Brain function assessment in different conscious states.

PubMed

Ozgoren, Murat; Bayazit, Onur; Kocaaslan, Sibel; Gokmen, Necati; Oniz, Adile

2010-06-03

The study of brain functioning is a major challenge in neuroscience fields as human brain has a dynamic and ever changing information processing. Case is worsened with conditions where brain undergoes major changes in so-called different conscious states. Even though the exact definition of consciousness is a hard one, there are certain conditions where the descriptions have reached a consensus. The sleep and the anesthesia are different conditions which are separable from each other and also from wakefulness. The aim of our group has been to tackle the issue of brain functioning with setting up similar research conditions for these three conscious states. In order to achieve this goal we have designed an auditory stimulation battery with changing conditions to be recorded during a 40 channel EEG polygraph (Nuamps) session. The stimuli (modified mismatch, auditory evoked etc.) have been administered both in the operation room and the sleep lab via Embedded Interactive Stimulus Unit which was developed in our lab. The overall study has provided some results for three domains of consciousness. In order to be able to monitor the changes we have incorporated Bispectral Index Monitoring to both sleep and anesthesia conditions. The first stage results have provided a basic understanding in these altered states such that auditory stimuli have been successfully processed in both light and deep sleep stages. The anesthesia provides a sudden change in brain responsiveness; therefore a dosage dependent anesthetic administration has proved to be useful. The auditory processing was exemplified targeting N1 wave, with a thorough analysis from spectrogram to sLORETA. The frequency components were observed to be shifting throughout the stages. The propofol administration and the deeper sleep stages both resulted in the decreasing of N1 component. The sLORETA revealed similar activity at BA7 in sleep (BIS 70) and target propofol concentration of 1.2 microg/mL. The current study utilized similar stimulation and recording system and incorporated BIS dependent values to validate a common approach to sleep and anesthesia. Accordingly the brain has a complex behavior pattern, dynamically changing its responsiveness in accordance with stimulations and states.

Cellular registration without behavioral recall of olfactory sensory input under general anesthesia.

PubMed

Samuelsson, Andrew R; Brandon, Nicole R; Tang, Pei; Xu, Yan

2014-04-01

Previous studies suggest that sensory information is "received" but not "perceived" under general anesthesia. Whether and to what extent the brain continues to process sensory inputs in a drug-induced unconscious state remain unclear. One hundred seven rats were randomly assigned to 12 different anesthesia and odor exposure paradigms. The immunoreactivities of the immediate early gene products c-Fos and Egr1 as neural activity markers were combined with behavioral tests to assess the integrity and relationship of cellular and behavioral responsiveness to olfactory stimuli under a surgical plane of ketamine-xylazine general anesthesia. The olfactory sensory processing centers could distinguish the presence or absence of experimental odorants even when animals were fully anesthetized. In the anesthetized state, the c-Fos immunoreactivity in the higher olfactory cortices revealed a difference between novel and familiar odorants similar to that seen in the awake state, suggesting that the anesthetized brain functions beyond simply receiving external stimulation. Reexposing animals to odorants previously experienced only under anesthesia resulted in c-Fos immunoreactivity, which was similar to that elicited by familiar odorants, indicating that previous registration had occurred in the anesthetized brain. Despite the "cellular memory," however, odor discrimination and forced-choice odor-recognition tests showed absence of behavioral recall of the registered sensations, except for a longer latency in odor recognition tests. Histologically distinguishable registration of sensory processing continues to occur at the cellular level under ketamine-xylazine general anesthesia despite the absence of behavioral recognition, consistent with the notion that general anesthesia causes disintegration of information processing without completely blocking cellular communications.

Cellular Registration Without Behavioral Recall Of Olfactory Sensory Input Under General Anesthesia

PubMed Central

Samuelsson, Andrew R.; Brandon, Nicole R.; Tang, Pei; Xu, Yan

2014-01-01

Background Previous studies suggest that sensory information is “received” but not “perceived” under general anesthesia. Whether and to what extent the brain continues to process sensory inputs in a drug-induced unconscious state remain unclear. Methods 107 rats were randomly assigned to 12 different anesthesia and odor exposure paradigms. The immunoreactivities of the immediate early gene products c-Fos and Egr1 as neural activity markers were combined with behavioral tests to assess the integrity and relationship of cellular and behavioral responsiveness to olfactory stimuli under a surgical plane of ketamine-xylazine general anesthesia. Results The olfactory sensory processing centers can distinguish the presence or absence of experimental odorants even when animals were fully anesthetized. In the anesthetized state, the c-Fos immunoreactivity in the higher olfactory cortices revealed a difference between novel and familiar odorants similar to that seen in the awake state, suggesting that the anesthetized brain functions beyond simply receiving external stimulation. Re-exposing animals to odorants previously experienced only under anesthesia resulted in c-Fos immunoreactivity similar to that elicited by familiar odorants, indicating that previous registration had occurred in the anesthetized brain. Despite the “cellular memory,” however, odor discrimination and forced-choice odor-recognition tests showed absence of behavioral recall of the registered sensations, except for a longer latency in odor recognition tests. Conclusions Histologically distinguishable registration of sensory process continues to occur at cellular level under ketamine-xylazine general anesthesia despite the absence of behavioral recognition, consistent with the notion that general anesthesia causes disintegration of information processing without completely blocking cellular communications. PMID:24694846

Efflux of drugs and solutes from brain: the interactive roles of diffusional transcapillary transport, bulk flow and capillary transporters.

PubMed

Groothuis, Dennis R; Vavra, Michael W; Schlageter, Kurt E; Kang, Eric W-Y; Itskovich, Andrea C; Hertzler, Shannon; Allen, Cathleen V; Lipton, Howard L

2007-01-01

We examined the roles of diffusion, convection and capillary transporters in solute removal from extracellular space (ECS) of the brain. Radiolabeled solutes (eight with passive distribution and four with capillary or cell transporters) were injected into the brains of rats (n=497) and multiple-time point experiments measured the amount remaining in brain as a function of time. For passively distributed compounds, there was a relationship between lipid:water solubility and total brain efflux:diffusional efflux, which dominated when k(p), the transcapillary efflux rate constant, was >10(0) h(-1); when 10(-1)

Optical imaging of the rat brain suggests a previously missing link between top-down and bottom-up nervous system function

PubMed Central

Greenfield, Susan A.; Badin, Antoine-Scott; Ferrati, Giovanni; Devonshire, Ian M.

2017-01-01

Abstract. Optical imaging with voltage-sensitive dyes enables the visualization of extensive yet highly transient coalitions of neurons (assemblies) operating throughout the brain on a subsecond time scale. We suggest that operating at the mesoscale level of brain organization, neuronal assemblies may provide a functional link between “bottom-up” cellular mechanisms and “top-down” cognitive ones within anatomically defined regions. We demonstrate in ex vivo rat brain slices how varying spatiotemporal dynamics of assemblies reveal differences not previously appreciated between: different stages of development in cortical versus subcortical brain areas, different sensory modalities (hearing versus vision), different classes of psychoactive drugs (anesthetics versus analgesics), different effects of anesthesia linked to hyperbaric conditions and, in vivo, depths of anesthesia. The strategy of voltage-sensitive dye imaging is therefore as powerful as it is versatile and as such can now be applied to the evaluation of neurochemical signaling systems and the screening of related new drugs, as well as to mathematical modeling and, eventually, even theories of consciousness. PMID:28573153

Optical imaging of the rat brain suggests a previously missing link between top-down and bottom-up nervous system function.

PubMed

Greenfield, Susan A; Badin, Antoine-Scott; Ferrati, Giovanni; Devonshire, Ian M

2017-07-01

Optical imaging with voltage-sensitive dyes enables the visualization of extensive yet highly transient coalitions of neurons (assemblies) operating throughout the brain on a subsecond time scale. We suggest that operating at the mesoscale level of brain organization, neuronal assemblies may provide a functional link between "bottom-up" cellular mechanisms and "top-down" cognitive ones within anatomically defined regions. We demonstrate in ex vivo rat brain slices how varying spatiotemporal dynamics of assemblies reveal differences not previously appreciated between: different stages of development in cortical versus subcortical brain areas, different sensory modalities (hearing versus vision), different classes of psychoactive drugs (anesthetics versus analgesics), different effects of anesthesia linked to hyperbaric conditions and, in vivo , depths of anesthesia. The strategy of voltage-sensitive dye imaging is therefore as powerful as it is versatile and as such can now be applied to the evaluation of neurochemical signaling systems and the screening of related new drugs, as well as to mathematical modeling and, eventually, even theories of consciousness.

Mapping oxygen concentration in the awake mouse brain

PubMed Central

Lyons, Declan G; Parpaleix, Alexandre; Roche, Morgane; Charpak, Serge

2016-01-01

Although critical for brain function, the physiological values of cerebral oxygen concentration have remained elusive because high-resolution measurements have only been performed during anesthesia, which affects two major parameters modulating tissue oxygenation: neuronal activity and blood flow. Using measurements of capillary erythrocyte-associated transients, fluctuations of oxygen partial pressure (Po2) associated with individual erythrocytes, to infer Po2 in the nearby neuropil, we report the first non-invasive micron-scale mapping of cerebral Po2 in awake, resting mice. Interstitial Po2 has similar values in the olfactory bulb glomerular layer and the somatosensory cortex, whereas there are large capillary hematocrit and erythrocyte flux differences. Awake tissue Po2 is about half that under isoflurane anesthesia, and within the cortex, vascular and interstitial Po2 values display layer-specific differences which dramatically contrast with those recorded under anesthesia. Our findings emphasize the importance of measuring energy parameters non-invasively in physiological conditions to precisely quantify and model brain metabolism. DOI: http://dx.doi.org/10.7554/eLife.12024.001 PMID:26836304

Mapping oxygen concentration in the awake mouse brain.

PubMed

Lyons, Declan G; Parpaleix, Alexandre; Roche, Morgane; Charpak, Serge

2016-02-02

Although critical for brain function, the physiological values of cerebral oxygen concentration have remained elusive because high-resolution measurements have only been performed during anesthesia, which affects two major parameters modulating tissue oxygenation: neuronal activity and blood flow. Using measurements of capillary erythrocyte-associated transients, fluctuations of oxygen partial pressure (Po2) associated with individual erythrocytes, to infer Po2 in the nearby neuropil, we report the first non-invasive micron-scale mapping of cerebral Po2 in awake, resting mice. Interstitial Po2 has similar values in the olfactory bulb glomerular layer and the somatosensory cortex, whereas there are large capillary hematocrit and erythrocyte flux differences. Awake tissue Po2 is about half that under isoflurane anesthesia, and within the cortex, vascular and interstitial Po2 values display layer-specific differences which dramatically contrast with those recorded under anesthesia. Our findings emphasize the importance of measuring energy parameters non-invasively in physiological conditions to precisely quantify and model brain metabolism.

Robust Brain Hyperglycemia during General Anesthesia: Relationships with Metabolic Brain Inhibition and Vasodilation

PubMed Central

Bola, R. Aaron; Kiyatkin, Eugene A.

2016-01-01

Glucose is the main energetic substrate for the metabolic activity of brain cells and its proper delivery into the extracellular space is essential for maintaining normal neural functions. Under physiological conditions, glucose continuously enters the extracellular space from arterial blood via gradient-dependent facilitated diffusion governed by the GLUT-1 transporters. Due to this gradient-dependent mechanism, glucose levels rise in the brain after consumption of glucose-containing foods and drinks. Glucose entry is also accelerated due to local neuronal activation and neuro-vascular coupling, resulting in transient hyperglycemia to prevent any metabolic deficit. Here, we explored another mechanism that is activated during general anesthesia and results in significant brain hyperglycemia. By using enzyme-based glucose biosensors we demonstrate that glucose levels in the nucleus accumbens (NAc) strongly increase after iv injection of Equthesin, a mixture of chloral hydrate and sodium pentobarbital, which is often used for general anesthesia in rats. By combining electrochemical recordings with brain, muscle, and skin temperature monitoring, we show that the gradual increase in brain glucose occurring during the development of general anesthesia tightly correlate with decreases in brain-muscle temperature differentials, suggesting that this rise in glucose is related to metabolic inhibition. While the decreased consumption of glucose by brain cells could contribute to the development of hyperglycemia, an exceptionally strong positive correlation (r = 0.99) between glucose rise and increases in skin-muscle temperature differentials was also found, suggesting the strong vasodilation of cerebral vessels as the primary mechanism for accelerated entry of glucose into brain tissue. Our present data could explain drastic differences in basal glucose levels found in awake and anesthetized animal preparations. They also suggest that glucose entry into brain tissue could be strongly modulated by pharmacological drugs via drug-induced changes in metabolic activity and the tone of cerebral vessels. PMID:26913008

Ketamine anesthesia during the first week of life can cause long-lasting cognitive deficits in rhesus monkeys.

PubMed

Paule, M G; Li, M; Allen, R R; Liu, F; Zou, X; Hotchkiss, C; Hanig, J P; Patterson, T A; Slikker, W; Wang, C

2011-01-01

Previously our laboratory has shown that ketamine exposure (24h of clinically relevant anesthesia) causes significant increases in neuronal cell death in perinatal rhesus monkeys. Sensitivity to this ketamine-induced neurotoxicity was observed on gestational days 120-123 (in utero exposure via maternal anesthesia) and on postnatal days (PNDs) 5-6, but not on PNDs 35-37. In the present study, six monkeys were exposed on PND 5 or 6 to intravenous ketamine anesthesia to maintain a light surgical plane for 24h and six control animals were unexposed. At 7 months of age all animals were weaned and began training to perform a series of cognitive function tasks as part of the National Center for Toxicological Research (NCTR) Operant Test Battery (OTB). The OTB tasks used here included those for assessing aspects of learning, motivation, color discrimination, and short-term memory. Subjects responded for banana-flavored food pellets by pressing response levers and press-plates during daily (M-F) test sessions (50 min) and were assigned training scores based upon their individual performance. As reported earlier (Paule et al., 2009) beginning around 10 months of age, control animals significantly outperformed (had higher training scores than) ketamine-exposed animals for approximately the next 10 months. For animals now over 3 and one-half years of age, the cognitive impairments continue to manifest in the ketamine-exposed group as poorer performance in the OTB learning and color and position discrimination tasks, as deficits in accuracy of task performance, but also in response speed. There are also apparent differences in the motivation of these animals which may be impacting OTB performance. These observations demonstrate that a single 24-h episode of ketamine anesthesia, occurring during a sensitive period of brain development, results in very long-lasting deficits in brain function in primates and provide proof-of-concept that general anesthesia during critical periods of brain development can result in subsequent functional deficits. Supported by NICHD, CDER/FDA and NCTR/FDA. Published by Elsevier Inc.

Surgery upregulates high mobility group box-1 and disrupts the blood-brain barrier causing cognitive dysfunction in aged rats.

PubMed

He, Hui-Juan; Wang, Yi; Le, Yuan; Duan, Kai-Ming; Yan, Xue-Bin; Liao, Qin; Liao, Yan; Tong, Jian-Bin; Terrando, Niccolò; Ouyang, Wen

2012-12-01

Postoperative cognitive dysfunction (POCD) is a growing and largely underestimated problem without defined etiology. Herein, we sought to determine the relationship between cognitive decline, blood-brain barrier (BBB) permeability, and inflammation, namely high mobility group box-1 (HMGB1), after surgery in aged rats. Aged rats were randomly assigned as surgery group (n = 45, splenectomy under general anesthesia), anesthesia (n = 45, 2% isoflurane for 2 h), and naïve control (n = 15). Markers of inflammation were measured in plasma and brain. Blood-brain barrier ultrastructure and permeability were measured by transmission electron microscope (TEM) and IgG immunohistochemistry. Cognitive function was assessed in a reversal learning version of the Morris water maze (MWM). Surgical trauma under general anesthesia caused distinct changes in systemic and central proinflammatory cytokines. Levels of HMGB1 and the receptor for advanced glycation end products (RAGE) were significantly upregulated in the hippocampus of operated animals. Immunohistochemistry and TEM showed BBB disruption induced by surgery and anesthesia. These molecular changes were associated with cognitive impairment in latency with the MWM up to postoperative day 3. HMGB1 and RAGE signaling appear pivotal mediators of surgery-induced cognitive decline and may contribute to the changes in BBB permeability after peripheral surgical trauma. © 2012 Blackwell Publishing Ltd.

Deep brain stimulation

MedlinePlus

... the skull Problems with speech, memory, muscle weakness, balance, vision, coordination, and other functions, which may be short-term or permanent Seizures Stroke Risks of general anesthesia are: Reactions to medicines Problems breathing

A comparison of functional magnetic resonance imaging findings in children with and without a history of early exposure to general anesthesia.

PubMed

Taghon, Thomas A; Masunga, Abigail N; Small, Robert H; Kashou, Nasser H

2015-03-01

Functional magnetic resonance imaging (fMRI) has been used to evaluate the long-term consequences of early exposure to neurotoxic agents. fMRI shows that different patterns of brain activation occur in ethanol-exposed subjects performing a go/no-go response inhibition task. Pharmacologically, ethanol and general anesthetics have similar receptor-level activity in the brain. This study utilizes fMRI to examine brain activation patterns in children exposed to general anesthesia and surgery during early brain development. After obtaining Nationwide Children's Hospital IRB approval, a surgical database was utilized to identify children aged 10-17 years with a history of at least 1 h of exposure to general anesthetics and surgery when they were between 0 and 24 months of age. Age- and gender-matched children without anesthesia exposure were recruited as a control group. All subjects were scanned while being presented with a go/no-go response inhibition task. Reaction time and accuracy data were acquired, and the blood-oxygen-level-dependent (BOLD) fMRI signal was measured as a biomarker for regional neuronal activity. There were no differences in terms of performance accuracy and response time. The analysis did not reveal any significant activation differences in the primary region of interest (prefrontal cortex and caudate nucleus); however, activation differences were seen in other structures, including the cerebellum, cingulate gyrus, and paracentral lobule. Early anesthetic exposure and surgery did not affect accuracy, response time, or activation patterns in the primary region of interest during performance of the task. Intergroup differences in activation patterns in other areas of the brain were observed, and the significance of these findings is unknown. fMRI appears to be a useful tool in evaluating the long-term effects of early exposure to general anesthesia. © 2015 John Wiley & Sons Ltd.

Method of euthanasia affects amygdala plasticity in horizontal brain slices from mice.

PubMed

Kulisch, C; Eckers, N; Albrecht, D

2011-10-15

An important consideration in any terminal experiment is the method used for euthanizing animals. Although the prime consideration is that the method is humane, some methods can have a dramatic impact on experimental outcomes. The standard inhalant anesthetic for experiments in brain slices is isoflurane, which replaced the flammable ethers used in the pioneer days of surgery. To our knowledge, there are no data available evaluating the effects of the method of euthanasia on plasticity changes in brain slices. Here, we compare the magnitude of long-term potentiation (LTP) and long-term depression (LTD) in the lateral nucleus of the amygdala (LA) after euthanasia following either ether or isoflurane anesthesia, as well as in mice decapitated without anesthesia. We found no differences in input-output curves using different methods of euthanasia. The LTP magnitude did not differ between ether and normal isoflurane anesthesia. After deep isoflurane anesthesia LTP induced by high frequency stimulation of cortical or intranuclear afferents was significantly reduced compared to ether anesthesia. In contrast to ether anesthesia and decapitation without anesthesia, the low frequency stimulation of cortical afferents induced a reliable LA-LTD after deep isoflurane anesthesia. Low frequency stimulation of intranuclear afferents only caused LTD after pretreatment with ether anesthesia. The results demonstrate that the method of euthanasia can influence brain plasticity for hours at least in the interface chamber. Therefore, the method of euthanasia is an important consideration when brain plasticity will be evaluated. Copyright © 2011 Elsevier B.V. All rights reserved.

Spinal anesthesia in infants: recent developments.

PubMed

Tirmizi, Henna

2015-06-01

Spinal anesthesia has long been described as a well-tolerated and effective means of providing anesthesia for infants undergoing lower abdominal surgery. Now, spinal anesthetics are being used for an increasing variety of surgeries previously believed to require a general anesthetic. This, along with increasing concerns over the neurocognitive effects of general anesthetics on developing brains, suggests that further exploration into this technique and its effects is essential. Exposure to spinal anesthesia in infancy has not shown the same suggestions of neurocognitive detriment as those resulting from general anesthesia. Ultrasound guidance has enhanced spinal technique by providing real-time guidance into the intrathecal space and confirming medication administration location, as well as helping avoid adverse outcomes by identifying aberrant anatomy. Spinal anesthesia provides benefits over general anesthesia, including cardiorespiratory stability, shorter postoperative recovery, and faster return of gastrointestinal function. Early findings of spinal anesthesia exposure in infancy have shown it to have no independent effect on neurocognitive delay as well as to provide sound cardiorespiratory stability. With safer means of administering a spinal anesthetic, such as with ultrasound guidance, it is a readily available and desirable tool for those providing anesthesia to infants.

The Potential Benefits of Awake Craniotomy for Brain Tumor Resection: An Anesthesiologist's Perspective.

PubMed

Meng, Lingzhong; Berger, Mitchel S; Gelb, Adrian W

2015-10-01

Awake craniotomy for brain tumor resection is becoming a standard of care for lesions residing within or in close proximity to regions presumed to have language or sensorimotor function. Evidence shows an improved outcome including greater extent of resection, fewer late neurological deficits, shorter hospital stay, and longer survival after awake brain tumor resection compared with surgery under general anesthesia. The surgeon's ability to maximize tumor resection within the constraint of preserving neurological function by intraoperative stimulation mapping in an awake patient is credited for this advantageous result. It is possible that the care provided by anesthesiologists, especially the avoidance of certain components of general endotracheal anesthesia, may also be important in the outcome of awake brain tumor resection. We present our interpretation of the evidence that we believe substantiates this proposition. However, due to the lack of direct evidence based on randomized-controlled trials and the heterogeneity of anesthetic techniques used for awake craniotomy, our perspective is largely speculative and hypothesis generating that needs to be validated or refuted by future quality research.

General Anesthesia and Human Brain Connectivity

PubMed Central

2012-01-01

Abstract General anesthesia consists of amnesia, hypnosis, analgesia, and areflexia. Of these, the mechanism of hypnosis, or loss of consciousness, has been the most elusive, yet a fascinating problem. How anesthetic agents suppress human consciousness has been investigated with neuroimaging for two decades. Anesthetics substantially reduce the global cerebral metabolic rate and blood flow with a degree of regional heterogeneity characteristic to the anesthetic agent. The thalamus appears to be a common site of modulation by several anesthetics, but this may be secondary to cortical effects. Stimulus-dependent brain activation is preserved in primary sensory areas, suggesting that unconsciousness cannot be explained by cortical deafferentation or a diminution of cortical sensory reactivity. The effect of general anesthetics in functional and effective connectivity is varied depending on the agent, dose, and network studied. At an anesthetic depth characterized by the subjects' unresponsiveness, a partial, but not complete, reduction in connectivity is generally observed. Functional connectivity of the frontoparietal association cortex is often reduced, but a causal role of this change for the loss of consciousness remains uncertain. Functional connectivity of the nonspecific (intralaminar) thalamic nuclei is preferentially reduced by propofol. Higher-order thalamocortical connectivity is also reduced with certain anesthetics. The changes in functional connectivity during anesthesia induction and emergence do not mirror each other; the recovery from anesthesia may involve increases in functional connectivity above the normal wakeful baseline. Anesthetic loss of consciousness is not a block of corticofugal information transfer, but a disruption of higher-order cortical information integration. The prime candidates for functional networks of the forebrain that play a critical role in maintaining the state of consciousness are those based on the posterior parietal-cingulate-precuneus region and the nonspecific thalamus. PMID:23153273

Anesthesia and perioperative stress: consequences on neural networks and postoperative behaviors.

PubMed

Borsook, David; George, Edward; Kussman, Barry; Becerra, Lino

2010-12-01

Anesthesia is a state of drug-induced unconsciousness with suppression of sensory perception, and consists of both hypnotic and analgesic components. The anesthesiologist monitors the clinical response to noxious stimuli and adjusts drug dosage(s) to achieve an adequate depth of anesthesia, with the aim of reducing operative stress. Acute stress in the perioperative period has four major contributors: anxiety, pain, the surgical stress response, and the potential neurotoxicity of anesthetic agents. Any or all of these may act deleteriously on multiple systems in the brain and have known significant effects on brain regions such as the hippocampus and the hypothalamic-pituitary-adrenal axis. Perioperative stress on the nervous system and the resultant central nervous system (CNS) changes are likely to be causative for altered behaviors that are seen postoperatively, including chronic pain, posttraumatic stress disorder, and learning difficulties. Improving the ability of the anesthesiologist to control all four components of acute perioperative stress could potentially reduce the negative impact of surgery on the brain. Currently, there is no objective measurement for any of these stressors. The development and application of objective measures for perioperative stressors is the first step towards controlling these risk factors and eliminating or reducing their serious postoperative consequences. In this paper we review known and likely effects of perioperative stressors on brain systems and how they may play a significant role in altered postoperative behaviors. We discuss the role of current (and developing) measures of brain function and their potential for monitoring perioperative stress, with an emphasis on functional neuroimaging. Copyright © 2010 Elsevier Ltd. All rights reserved.

Influence of anesthesia on cerebral blood flow, cerebral metabolic rate, and brain functional connectivity.

PubMed

Bonhomme, Vincent; Boveroux, Pierre; Hans, Pol; Brichant, Jean François; Vanhaudenhuyse, Audrey; Boly, Melanie; Laureys, Steven

2011-10-01

To describe recent studies exploring brain function under the influence of hypnotic anesthetic agents, and their implications on the understanding of consciousness physiology and anesthesia-induced alteration of consciousness. Cerebral cortex is the primary target of the hypnotic effect of anesthetic agents, and higher-order association areas are more sensitive to this effect than lower-order processing regions. Increasing concentration of anesthetic agents progressively attenuates connectivity in the consciousness networks, while connectivity in lower-order sensory and motor networks is preserved. Alteration of thalamic sub-cortical regulation could compromise the cortical integration of information despite preserved thalamic activation by external stimuli. At concentrations producing unresponsiveness, the activity of consciousness networks becomes anticorrelated with thalamic activity, while connectivity in lower-order sensory networks persists, although with cross-modal interaction alterations. Accumulating evidence suggests that hypnotic anesthetic agents disrupt large-scale cerebral connectivity. This would result in an inability of the brain to generate and integrate information, while external sensory information is still processed at a lower order of complexity.

Accelerated Recovery of Consciousness after General Anesthesia Is Associated with Increased Functional Brain Connectivity in the High-Gamma Bandwidth.

PubMed

Li, Duan; Hambrecht-Wiedbusch, Viviane S; Mashour, George A

2017-01-01

Recent data from our laboratory demonstrate that high-frequency gamma connectivity across the cortex is present during consciousness and depressed during unconsciousness. However, these data were derived from static and well-defined states of arousal rather than during transitions that would suggest functional relevance. We also recently found that subanesthetic ketamine administered during isoflurane anesthesia accelerates recovery upon discontinuation of the primary anesthetic and increases gamma power during emergence. In the current study we re-analyzed electroencephalogram (EEG) data to test the hypothesis that functional cortical connectivity between anterior and posterior cortical regions would be increased during accelerated recovery induced by ketamine when compared to saline-treated controls. Rodents were instrumented with intracranial EEG electrodes and general anesthesia was induced with isoflurane anesthesia. After 37.5 min of continuous isoflurane anesthesia, a subanesthetic dose of ketamine (25 mg/kg intraperitoneal) was administered, with evidence of a 44% reduction in emergence time. In this study, we analyzed gamma and theta coherence (measure of undirected functional connectivity) and normalized symbolic transfer entropy (measure of directed functional connectivity) between frontal and parietal cortices during various levels of consciousness, with a focus on emergence from isoflurane anesthesia. During accelerated emergence in the ketamine-treated group, there was increased frontal-parietal coherence { p = 0.005, 0.05-0.23 [95% confidence interval (CI)]} and normalized symbolic transfer entropy [frontal to parietal: p < 0.001, 0.010-0.026 (95% CI); parietal to frontal: p < 0.001, 0.009-0.025 (95% CI)] in high-frequency gamma bandwidth as compared with the saline-treated group. Surrogates of cortical information exchange in high-frequency gamma are increased in association with accelerated recovery from anesthesia. This finding adds evidence suggesting a functional significance of high-gamma information transfer in consciousness.

Spinal Anesthesia in Infant Rats: Development of a Model and Assessment of Neurological Outcomes

PubMed Central

Yahalom, Barak; Athiraman, Umeshkumar; Soriano, Sulpicio G.; Zurakowski, David; Carpino, Elizabeth; Corfas, Gabriel; Berde, Charles B.

2012-01-01

Background Previous studies in infant rats and case-control studies of human infants undergoing surgery have raised concerns about potential neurodevelopmental toxicities of general anesthesia. Spinal anesthesia is an alternative to general anesthesia for some infant surgeries. To test for potential toxicity, we developed a spinal anesthesia model in infant rats. Methods Rats of postnatal ages 7, 14, and 21 days were assigned to: no treatment; 1% isoflurane for either 1 h or 6 h, or lumbar spinal injection of saline or bupivacaine, at doses of 3.75 mg/kg (low dose) or 7.5 mg/kg (high dose). Subgroups of animals underwent neurobehavioral testing and blood gas analysis. Brain and lumbar spinal cord sections were examined for apoptosis using cleaved caspase-3 immunostaining. Lumbar spinal cord was examined histologically. Rats exposed to spinal or general anesthesia as infants underwent Rotarod testing of motor performance as adults. Data were analyzed using analysis of variance (ANOVA) using general linear models, Friedman Tests, and Mann–Whitney U tests, as appropriate. Results Bupivacaine 3.75 mg/kg was effective for spinal anesthesia in all age groups, and produced sensory and motor function recovered in 40 to 60 min. Blood gases were similar among groups. Brain and spinal cord apoptosis increased in rats receiving 6 h of 1% isoflurane, but not among the other treatments. All groups showed intact motor performance at adulthood. Conclusions Spinal anesthesia is technically feasible in infant rats, and appears benign in terms of neuroapoptotic and neuromotor sequelae. PMID:21555934

Anesthesia-induced epilepsy: causes and treatment.

PubMed

Zhao, Xiaojuan; Wang, Xuefeng

2014-09-01

Epilepsy is a type of chronic brain disease that results from an abnormally high synchronization of neuronal discharge. The typical clinical features of epilepsy are paroxysms and transient and stereotyped brain dysfunction. Many cases of epileptic seizures occurring during anesthesia have been reportedx. Recently, risk assessment of epileptic seizures during surgery and anesthesia has gained increasing attention. In this review, we systematically summarize the influence of anesthesia on epileptic seizures; the types, durations and frequencies of seizures related to anesthesia; and the epidemiology, prevention, treatment and prognosis of epilepsy. We also explore the possible mechanism of epilepsy and provide guidance for anesthesia during surgeries.

Body and brain temperature coupling: the critical role of cerebral blood flow

PubMed Central

Ackerman, Joseph J. H.; Yablonskiy, Dmitriy A.

2010-01-01

Direct measurements of deep-brain and body-core temperature were performed on rats to determine the influence of cerebral blood flow (CBF) on brain temperature regulation under static and dynamic conditions. Static changes of CBF were achieved using different anesthetics (chloral hydrate, CH; α-chloralose, αCS; and isoflurane, IF) with αCS causing larger decreases in CBF than CH and IF; dynamic changes were achieved by inducing transient hypercapnia (5% CO2 in 40% O2 and 55% N2). Initial deep-brain/body-core temperature differentials were anesthetic-type dependent with the largest differential observed with rats under αCS anesthesia (ca. 2°C). Hypercapnia induction raised rat brain temperature under all three anesthesia regimes, but by different anesthetic-dependent amounts correlated with the initial differentials—αCS anesthesia resulted in the largest brain temperature increase (0.32 ± 0.08°C), while CH and IF anesthesia lead to smaller increases (0.12 ± 0.03 and 0.16 ± 0.05°C, respectively). The characteristic temperature transition time for the hypercapnia-induced temperature increase was 2–3 min under CH and IF anesthesia and ~4 min under αCS anesthesia. We conclude that both, the deep-brain/body-core temperature differential and the characteristic temperature transition time correlate with CBF: a lower CBF promotes higher deep-brain/body-core temperature differentials and, upon hypercapnia challenge, longer characteristic transition times to increased temperatures. PMID:19277681

Body and brain temperature coupling: the critical role of cerebral blood flow.

PubMed

Zhu, Mingming; Ackerman, Joseph J H; Yablonskiy, Dmitriy A

2009-08-01

Direct measurements of deep-brain and body-core temperature were performed on rats to determine the influence of cerebral blood flow (CBF) on brain temperature regulation under static and dynamic conditions. Static changes of CBF were achieved using different anesthetics (chloral hydrate, CH; alpha-chloralose, alphaCS; and isoflurane, IF) with alphaCS causing larger decreases in CBF than CH and IF; dynamic changes were achieved by inducing transient hypercapnia (5% CO(2) in 40% O(2) and 55% N(2)). Initial deep-brain/body-core temperature differentials were anesthetic-type dependent with the largest differential observed with rats under alphaCS anesthesia (ca. 2 degrees C). Hypercapnia induction raised rat brain temperature under all three anesthesia regimes, but by different anesthetic-dependent amounts correlated with the initial differentials--alphaCS anesthesia resulted in the largest brain temperature increase (0.32 +/- 0.08 degrees C), while CH and IF anesthesia lead to smaller increases (0.12 +/- 0.03 and 0.16 +/- 0.05 degrees C, respectively). The characteristic temperature transition time for the hypercapnia-induced temperature increase was 2-3 min under CH and IF anesthesia and approximately 4 min under alphaCS anesthesia. We conclude that both, the deep-brain/body-core temperature differential and the characteristic temperature transition time correlate with CBF: a lower CBF promotes higher deep-brain/body-core temperature differentials and, upon hypercapnia challenge, longer characteristic transition times to increased temperatures.

Quantitative EEG correlations with brain glucose metabolic rate during anesthesia in volunteers.

PubMed

Alkire, M T

1998-08-01

To help elucidate the relationship between anesthetic-induced changes in the electroencephalogram (EEG) and the concurrent cerebral metabolic changes caused by anesthesia, positron emission tomography data of cerebral metabolism obtained in volunteers during anesthesia were correlated retrospectively with various concurrently measured EEG descriptors. Volunteers underwent functional brain imaging using the 18fluorodeoxyglucose technique; one scan always assessed awake-baseline cerebral metabolism (n = 7), and the other scans assessed metabolism during propofol sedation (n = 4), propofol anesthesia (n = 4), or isoflurane anesthesia (n = 5). The EEG was recorded continuously during metabolism assessment using a frontal-mastoid montage. Power spectrum variables, median frequency, 95% spectral edge, and bispectral index (BIS) values subsequently were correlated with the percentage of absolute cerebral metabolic reduction (PACMR) of glucose utilization caused by anesthesia. The percentage of absolute cerebral metabolic reduction, evident during anesthesia, trended median frequency (r = -0.46, P = 0.11), and the spectral edge (r = -0.52, P = 0.07), and correlated with anesthetic type (r = -0.70, P < 0.05), relative beta power (r = -0.60, P < 0.05), total power (r = 0.71,P < 0.01), and bispectral index (r = -0.81,P < 0.001). After controlling for anesthetic type, only bispectral index (r = 0.40, P = 0.08) and alpha power (r = 0.37, P = 0.10) approached significance for explaining residual percentage of absolute cerebral metabolic reduction prediction error. Some EEG descriptors correlated linearly with the magnitude of the cerebral metabolic reduction caused by propofol and isoflurane anesthesia. These data suggest that a physiologic link exists between the EEG and cerebral metabolism during anesthesia that is mathematically quantifiable.

Effect of different anesthesia techniques on the serum brain-derived neurotrophic factor (BDNF) levels.

PubMed

Ozer, A B; Demirel, I; Erhan, O L; Firdolas, F; Ustundag, B

2015-10-01

Serum Brain-Derived Neurotrophic Factor (BDNF) levels are associated with neurotransmission and cognitive functions. The goal of this study was to examine the effect of general anesthesia on BDNF levels. It was also to reveal whether this effect had a relationship with the surgical stress response or not. The study included 50 male patients, age 20-40, who were scheduled to have inguinoscrotal surgery, and who were in the ASA I-II risk group. The patients were divided into two groups according to the anesthesia techniques used: general (GA) and spinal (SA). In order to measure serum BDNF, cortisol, insulin and glucose levels, blood samples were taken at four different times: before and after anesthesia, end of the surgery, and before transferal from the recovery room. Serum BDNF levels were significantly low (p < 0.01), cortisol and glucose levels were higher (p < 0.05 and p < 0.01) in Group GA compared with Group SA. No significant difference was detected between the groups in terms of serum insulin levels. There was no correlation between serum BDNF and the stress hormones. Our findings suggested that general anesthetics had an effect on serum BDNF levels independent of the stress response. In future, BDNF could be used as biochemical parameters of anesthesia levels, but studies with a greater scope should be carried out to present the relationship between anesthesia and neurotrophins.

Anaesthetic management for awake craniotomy in brain glioma resection: initial experience in Military Hospital Mohamed V of Rabat.

PubMed

Meziane, Mohammed; Elkoundi, Abdelghafour; Ahtil, Redouane; Guazaz, Miloudi; Mustapha, Bensghir; Haimeur, Charki

2017-01-01

The awake brain surgery is an innovative approach in the treatment of tumors in the functional areas of the brain. There are various anesthetic techniques for awake craniotomy (AC), including asleep-awake-asleep technique, monitored anesthesia care, and the recent introduced awake-awake-awake method. We describe our first experience with anesthetic management for awake craniotomy, which was a combination of these techniques with scalp nerve block, and propofol/rémifentanil target controlled infusion. A 28-year-oldmale underwent an awake craniotomy for brain glioma resection. The scalp nerve block was performed and a low sedative state was maintained until removal of bone flap. During brain glioma resection, the patient awake state was maintained without any complications. Once, the tumorectomy was completed, the level of anesthesia was deepened and a laryngeal mask airway was inserted. A well psychological preparation, a reasonable choice of anesthetic techniques and agents, and continuous team communication were some of the key challenges for successful outcome in our patient.

Comparison of NREM sleep and intravenous sedation through local information processing and whole brain network to explore the mechanism of general anesthesia.

PubMed

Li, Yun; Wang, Shengpei; Pan, Chuxiong; Xue, Fushan; Xian, Junfang; Huang, Yaqi; Wang, Xiaoyi; Li, Tianzuo; He, Huiguang

2018-01-01

The mechanism of general anesthesia (GA) has been explored for hundreds of years, but unclear. Previous studies indicated a possible correlation between NREM sleep and GA. The purpose of this study is to compare them by in vivo human brain function to probe the neuromechanism of consciousness, so as to find out a clue to GA mechanism. 24 healthy participants were equally assigned to sleep or propofol sedation group by sleeping ability. EEG and Ramsay Sedation Scale were applied to determine sleep stage and sedation depth respectively. Resting-state functional magnetic resonance imaging (RS-fMRI) was acquired at each status. Regional homogeneity (ReHo) and seed-based whole brain functional connectivity maps (WB-FC maps) were compared. During sleep, ReHo primarily weakened on frontal lobe (especially preoptic area), but strengthened on brainstem. While during sedation, ReHo changed in various brain areas, including cingulate, precuneus, thalamus and cerebellum. Cingulate, fusiform and insula were concomitance of sleep and sedation. Comparing to sleep, FCs between the cortex and subcortical centers (centralized in cerebellum) were significantly attenuated under sedation. As sedation deepening, cerebellum-based FC maps were diminished, while thalamus- and brainstem-based FC maps were increased. There're huge distinctions in human brain function between sleep and GA. Sleep mainly rely on brainstem and frontal lobe function, while sedation is prone to affect widespread functional network. The most significant differences exist in the precuneus and cingulate, which may play important roles in mechanisms of inducing unconciousness by anesthetics. Institutional Review Board (IRB) ChiCTR-IOC-15007454.

Brainstem stimulation increases functional connectivity of basal forebrain-paralimbic network in isoflurane-anesthetized rats.

PubMed

Pillay, Siveshigan; Liu, Xiping; Baracskay, Péter; Hudetz, Anthony G

2014-09-01

Brain states and cognitive-behavioral functions are precisely controlled by subcortical neuromodulatory networks. Manipulating key components of the ascending arousal system (AAS), via deep-brain stimulation, may help facilitate global arousal in anesthetized animals. Here we test the hypothesis that electrical stimulation of the oral part of the pontine reticular nucleus (PnO) under light isoflurane anesthesia, associated with loss of consciousness, leads to cortical desynchronization and specific changes in blood-oxygenation-level-dependent (BOLD) functional connectivity (FC) of the brain. BOLD signals were acquired simultaneously with frontal epidural electroencephalogram before and after PnO stimulation. Whole-brain FC was mapped using correlation analysis with seeds in major centers of the AAS. PnO stimulation produced cortical desynchronization, a decrease in δ- and θ-band power, and an increase in approximate entropy. Significant increases in FC after PnO stimulation occurred between the left nucleus Basalis of Meynert (NBM) as seed and numerous regions of the paralimbic network. Smaller increases in FC were present between the central medial thalamic nucleus and retrosplenium seeds and the left caudate putamen and NBM. The results suggest that, during light anesthesia, PnO stimulation preferentially modulates basal forebrain-paralimbic networks. We speculate that this may be a reflection of disconnected awareness.

Intrinsic Brain Activity in Altered States of Consciousness

PubMed Central

Boly, M.; Phillips, C.; Tshibanda, L.; Vanhaudenhuyse, A.; Schabus, M.; Dang-Vu, T.T.; Moonen, G.; Hustinx, R.; Maquet, P.; Laureys, S.

2010-01-01

Spontaneous brain activity has recently received increasing interest in the neuroimaging community. However, the value of resting-state studies to a better understanding of brain–behavior relationships has been challenged. That altered states of consciousness are a privileged way to study the relationships between spontaneous brain activity and behavior is proposed, and common resting-state brain activity features observed in various states of altered consciousness are reviewed. Early positron emission tomography studies showed that states of extremely low or high brain activity are often associated with unconsciousness. However, this relationship is not absolute, and the precise link between global brain metabolism and awareness remains yet difficult to assert. In contrast, voxel-based analyses identified a systematic impairment of associative frontoparieto–cingulate areas in altered states of consciousness, such as sleep, anesthesia, coma, vegetative state, epileptic loss of consciousness, and somnambulism. In parallel, recent functional magnetic resonance imaging studies have identified structured patterns of slow neuronal oscillations in the resting human brain. Similar coherent blood oxygen level–dependent (BOLD) systemwide patterns can also be found, in particular in the default-mode network, in several states of unconsciousness, such as coma, anesthesia, and slow-wave sleep. The latter results suggest that slow coherent spontaneous BOLD fluctuations cannot be exclusively a reflection of conscious mental activity, but may reflect default brain connectivity shaping brain areas of most likely interactions in a way that transcends levels of consciousness, and whose functional significance remains largely in the dark. PMID:18591474

In vivo proton MRS to quantify anesthetic effects of pentobarbital on cerebral metabolism and brain activity in rat.

PubMed

Du, Fei; Zhang, Yi; Iltis, Isabelle; Marjanska, Malgorzata; Zhu, Xiao-Hong; Henry, Pierre-Gilles; Chen, Wei

2009-12-01

To quantitatively investigate the effects of pentobarbital anesthesia on brain activity, brain metabolite concentrations and cerebral metabolic rate of glucose, in vivo proton MR spectra, and electroencephalography were measured in the rat brain with various doses of pentobarbital. The results show that (1) the resonances attributed to propylene glycol, a solvent in pentobarbital injection solution, can be robustly detected and quantified in the brain; (2) the concentration of most brain metabolites remained constant under the isoelectric state (silent electroencephalography) with a high dose of pentobarbital compared to mild isoflurane anesthesia condition, except for a reduction of 61% in the brain glucose level, which was associated with a 37% decrease in cerebral metabolic rate of glucose, suggesting a significant amount of "housekeeping" energy for maintaining brain cellular integrity under the isoelectric state; and (3) electroencephalography and cerebral metabolic activities were tightly coupled to the pentobarbital anesthesia depth and they can be indirectly quantified by the propylene glycol resonance signal at 1.13 ppm. This study indicates that in vivo proton MR spectroscopy can be used to measure changes in cerebral metabolite concentrations and cerebral metabolic rate of glucose under varied pentobarbital anesthesia states; moreover, the propylene glycol signal provides a sensitive biomarker for quantitatively monitoring these changes and anesthesia depth noninvasively. (c) 2009 Wiley-Liss, Inc.

Anesthetic management with scalp nerve block and propofol/remifentanil infusion during awake craniotomy in an adolescent patient -A case report-

PubMed Central

Sung, Bohyun; Park, Jin-Woo; Byon, Hyo-Jin; Kim, Jin-Tae; Kim, Chong Sung

2010-01-01

Despite of various neurophysiologic monitoring methods under general anesthesia, functional mapping at awake state during brain surgery is helpful for conservation of speech and motor function. But, awake craniotomy in children or adolescents is worrisome considering their emotional friabilities. We present our experience on anesthetic management for awake craniotomy in an adolescent patient. The patient was 16 years old male who would undergo awake craniotomy for removal of brain tumor. Scalp nerve block was done with local anesthetics and we infused propofol and remifentanil with target controlled infusion. The patient endured well and was cooperative before scalp suture, but when surgeon sutured scalp, he complained of pain and was suddenly agitated. We decided change to general anesthesia. Neurosurgeon did full neurologic examinations and there was no neurologic deficit except facial palsy of right side. Facial palsy had improved with time. PMID:21286435

Awake craniotomy for tumor resection.

PubMed

Attari, Mohammadali; Salimi, Sohrab

2013-01-01

Surgical treatment of brain tumors, especially those located in the eloquent areas such as anterior temporal, frontal lobes, language, memory areas, and near the motor cortex causes high risk of eloquent impairment. Awake craniotomy displays major rule for maximum resection of the tumor with minimum functional impairment of the Central Nervous System. These case reports discuss the use of awake craniotomy during the brain surgery in Alzahra Hospital, Isfahan, Iran. A 56-year-old woman with left-sided body hypoesthesia since last 3 months and a 25-year-old with severe headache of 1 month duration were operated under craniotomy for brain tumors resection. An awake craniotomy was planned to allow maximum tumor intraoperative testing for resection and neurologic morbidity avoidance. The method of anesthesia should offer sufficient analgesia, hemodynamic stability, sedation, respiratory function, and also awake and cooperative patient for different neurological test. Airway management is the most important part of anesthesia during awake craniotomy. Tumor surgery with awake craniotomy is a safe technique that allows maximal resection of lesions in close relationship to eloquent cortex and has a low risk of neurological deficit.

Awake craniotomy for tumor resection

PubMed Central

Attari, Mohammadali; Salimi, Sohrab

2013-01-01

Surgical treatment of brain tumors, especially those located in the eloquent areas such as anterior temporal, frontal lobes, language, memory areas, and near the motor cortex causes high risk of eloquent impairment. Awake craniotomy displays major rule for maximum resection of the tumor with minimum functional impairment of the Central Nervous System. These case reports discuss the use of awake craniotomy during the brain surgery in Alzahra Hospital, Isfahan, Iran. A 56-year-old woman with left-sided body hypoesthesia since last 3 months and a 25-year-old with severe headache of 1 month duration were operated under craniotomy for brain tumors resection. An awake craniotomy was planned to allow maximum tumor intraoperative testing for resection and neurologic morbidity avoidance. The method of anesthesia should offer sufficient analgesia, hemodynamic stability, sedation, respiratory function, and also awake and cooperative patient for different neurological test. Airway management is the most important part of anesthesia during awake craniotomy. Tumor surgery with awake craniotomy is a safe technique that allows maximal resection of lesions in close relationship to eloquent cortex and has a low risk of neurological deficit. PMID:24223378

Frequency and Type of Situational Awareness Errors Contributing to Death and Brain Damage: A Closed Claims Analysis.

PubMed

Schulz, Christian M; Burden, Amanda; Posner, Karen L; Mincer, Shawn L; Steadman, Randolph; Wagner, Klaus J; Domino, Karen B

2017-08-01

Situational awareness errors may play an important role in the genesis of patient harm. The authors examined closed anesthesia malpractice claims for death or brain damage to determine the frequency and type of situational awareness errors. Surgical and procedural anesthesia death and brain damage claims in the Anesthesia Closed Claims Project database were analyzed. Situational awareness error was defined as failure to perceive relevant clinical information, failure to comprehend the meaning of available information, or failure to project, anticipate, or plan. Patient and case characteristics, primary damaging events, and anesthesia payments in claims with situational awareness errors were compared to other death and brain damage claims from 2002 to 2013. Anesthesiologist situational awareness errors contributed to death or brain damage in 198 of 266 claims (74%). Respiratory system damaging events were more common in claims with situational awareness errors (56%) than other claims (21%, P < 0.001). The most common specific respiratory events in error claims were inadequate oxygenation or ventilation (24%), difficult intubation (11%), and aspiration (10%). Payments were made in 85% of situational awareness error claims compared to 46% in other claims (P = 0.001), with no significant difference in payment size. Among 198 claims with anesthesia situational awareness error, perception errors were most common (42%), whereas comprehension errors (29%) and projection errors (29%) were relatively less common. Situational awareness error definitions were operationalized for reliable application to real-world anesthesia cases. Situational awareness errors may have contributed to catastrophic outcomes in three quarters of recent anesthesia malpractice claims.Situational awareness errors resulting in death or brain damage remain prevalent causes of malpractice claims in the 21st century.

Comparison of NREM sleep and intravenous sedation through local information processing and whole brain network to explore the mechanism of general anesthesia

PubMed Central

Pan, Chuxiong; Xue, Fushan; Xian, Junfang; Huang, Yaqi; Wang, Xiaoyi; He, Huiguang

2018-01-01

Background The mechanism of general anesthesia (GA) has been explored for hundreds of years, but unclear. Previous studies indicated a possible correlation between NREM sleep and GA. The purpose of this study is to compare them by in vivo human brain function to probe the neuromechanism of consciousness, so as to find out a clue to GA mechanism. Methods 24 healthy participants were equally assigned to sleep or propofol sedation group by sleeping ability. EEG and Ramsay Sedation Scale were applied to determine sleep stage and sedation depth respectively. Resting-state functional magnetic resonance imaging (RS-fMRI) was acquired at each status. Regional homogeneity (ReHo) and seed-based whole brain functional connectivity maps (WB-FC maps) were compared. Results During sleep, ReHo primarily weakened on frontal lobe (especially preoptic area), but strengthened on brainstem. While during sedation, ReHo changed in various brain areas, including cingulate, precuneus, thalamus and cerebellum. Cingulate, fusiform and insula were concomitance of sleep and sedation. Comparing to sleep, FCs between the cortex and subcortical centers (centralized in cerebellum) were significantly attenuated under sedation. As sedation deepening, cerebellum-based FC maps were diminished, while thalamus- and brainstem-based FC maps were increased. Conclusion There’re huge distinctions in human brain function between sleep and GA. Sleep mainly rely on brainstem and frontal lobe function, while sedation is prone to affect widespread functional network. The most significant differences exist in the precuneus and cingulate, which may play important roles in mechanisms of inducing unconciousness by anesthetics. Trial registration Institutional Review Board (IRB) ChiCTR-IOC-15007454. PMID:29486001

Accelerated Recovery of Consciousness after General Anesthesia Is Associated with Increased Functional Brain Connectivity in the High-Gamma Bandwidth

PubMed Central

Li, Duan; Hambrecht-Wiedbusch, Viviane S.; Mashour, George A.

2017-01-01

Recent data from our laboratory demonstrate that high-frequency gamma connectivity across the cortex is present during consciousness and depressed during unconsciousness. However, these data were derived from static and well-defined states of arousal rather than during transitions that would suggest functional relevance. We also recently found that subanesthetic ketamine administered during isoflurane anesthesia accelerates recovery upon discontinuation of the primary anesthetic and increases gamma power during emergence. In the current study we re-analyzed electroencephalogram (EEG) data to test the hypothesis that functional cortical connectivity between anterior and posterior cortical regions would be increased during accelerated recovery induced by ketamine when compared to saline-treated controls. Rodents were instrumented with intracranial EEG electrodes and general anesthesia was induced with isoflurane anesthesia. After 37.5 min of continuous isoflurane anesthesia, a subanesthetic dose of ketamine (25 mg/kg intraperitoneal) was administered, with evidence of a 44% reduction in emergence time. In this study, we analyzed gamma and theta coherence (measure of undirected functional connectivity) and normalized symbolic transfer entropy (measure of directed functional connectivity) between frontal and parietal cortices during various levels of consciousness, with a focus on emergence from isoflurane anesthesia. During accelerated emergence in the ketamine-treated group, there was increased frontal-parietal coherence {p = 0.005, 0.05–0.23 [95% confidence interval (CI)]} and normalized symbolic transfer entropy [frontal to parietal: p < 0.001, 0.010–0.026 (95% CI); parietal to frontal: p < 0.001, 0.009–0.025 (95% CI)] in high-frequency gamma bandwidth as compared with the saline-treated group. Surrogates of cortical information exchange in high-frequency gamma are increased in association with accelerated recovery from anesthesia. This finding adds evidence suggesting a functional significance of high-gamma information transfer in consciousness. PMID:28392760

Anaesthetic management for awake craniotomy in brain glioma resection: initial experience in Military Hospital Mohamed V of Rabat

PubMed Central

Meziane, Mohammed; Elkoundi, Abdelghafour; Ahtil, Redouane; Guazaz, Miloudi; Mustapha, Bensghir; Haimeur, Charki

2017-01-01

The awake brain surgery is an innovative approach in the treatment of tumors in the functional areas of the brain. There are various anesthetic techniques for awake craniotomy (AC), including asleep-awake-asleep technique, monitored anesthesia care, and the recent introduced awake-awake-awake method. We describe our first experience with anesthetic management for awake craniotomy, which was a combination of these techniques with scalp nerve block, and propofol/rémifentanil target controlled infusion. A 28-year-oldmale underwent an awake craniotomy for brain glioma resection. The scalp nerve block was performed and a low sedative state was maintained until removal of bone flap. During brain glioma resection, the patient awake state was maintained without any complications. Once, the tumorectomy was completed, the level of anesthesia was deepened and a laryngeal mask airway was inserted. A well psychological preparation, a reasonable choice of anesthetic techniques and agents, and continuous team communication were some of the key challenges for successful outcome in our patient. PMID:28904684

Mechanisms underlying brain monitoring during anesthesia: limitations, possible improvements, and perspectives

PubMed Central

2016-01-01

Currently, anesthesiologists use clinical parameters to directly measure the depth of anesthesia (DoA). This clinical standard of monitoring is often combined with brain monitoring for better assessment of the hypnotic component of anesthesia. Brain monitoring devices provide indices allowing for an immediate assessment of the impact of anesthetics on consciousness. However, questions remain regarding the mechanisms underpinning these indices of hypnosis. By briefly describing current knowledge of the brain's electrical activity during general anesthesia, as well as the operating principles of DoA monitors, the aim of this work is to simplify our understanding of the mathematical processes that allow for translation of complex patterns of brain electrical activity into dimensionless indices. This is a challenging task because mathematical concepts appear remote from clinical practice. Moreover, most DoA algorithms are proprietary algorithms and the difficulty of exploring the inner workings of mathematical models represents an obstacle to accurate simplification. The limitations of current DoA monitors — and the possibility for improvement — as well as perspectives on brain monitoring derived from recent research on corticocortical connectivity and communication are also discussed. PMID:27066200

Functional and Topological Conditions for Explosive Synchronization Develop in Human Brain Networks with the Onset of Anesthetic-Induced Unconsciousness

PubMed Central

Kim, Minkyung; Mashour, George A.; Moraes, Stefanie-Blain; Vanini, Giancarlo; Tarnal, Vijay; Janke, Ellen; Hudetz, Anthony G.; Lee, Uncheol

2016-01-01

Sleep, anesthesia, and coma share a number of neural features but the recovery profiles are radically different. To understand the mechanisms of reversibility of unconsciousness at the network level, we studied the conditions for gradual and abrupt transitions in conscious and anesthetized states. We hypothesized that the conditions for explosive synchronization (ES) in human brain networks would be present in the anesthetized brain just over the threshold of unconsciousness. To test this hypothesis, functional brain networks were constructed from multi-channel electroencephalogram (EEG) recordings in seven healthy subjects across conscious, unconscious, and recovery states. We analyzed four variables that are involved in facilitating ES in generic, non-biological networks: (1) correlation between node degree and frequency, (2) disassortativity (i.e., the tendency of highly-connected nodes to link with less-connected nodes, or vice versa), (3) frequency difference of coupled nodes, and (4) an inequality relationship between local and global network properties, which is referred to as the suppressive rule. We observed that the four network conditions for ES were satisfied in the unconscious state. Conditions for ES in the human brain suggest a potential mechanism for rapid recovery from the lightly-anesthetized state. This study demonstrates for the first time that the network conditions for ES, formerly shown in generic networks only, are present in empirically-derived functional brain networks. Further investigations with deep anesthesia, sleep, and coma could provide insight into the underlying causes of variability in recovery profiles of these unconscious states. PMID:26834616

Functional and Topological Conditions for Explosive Synchronization Develop in Human Brain Networks with the Onset of Anesthetic-Induced Unconsciousness.

PubMed

Kim, Minkyung; Mashour, George A; Moraes, Stefanie-Blain; Vanini, Giancarlo; Tarnal, Vijay; Janke, Ellen; Hudetz, Anthony G; Lee, Uncheol

2016-01-01

Sleep, anesthesia, and coma share a number of neural features but the recovery profiles are radically different. To understand the mechanisms of reversibility of unconsciousness at the network level, we studied the conditions for gradual and abrupt transitions in conscious and anesthetized states. We hypothesized that the conditions for explosive synchronization (ES) in human brain networks would be present in the anesthetized brain just over the threshold of unconsciousness. To test this hypothesis, functional brain networks were constructed from multi-channel electroencephalogram (EEG) recordings in seven healthy subjects across conscious, unconscious, and recovery states. We analyzed four variables that are involved in facilitating ES in generic, non-biological networks: (1) correlation between node degree and frequency, (2) disassortativity (i.e., the tendency of highly-connected nodes to link with less-connected nodes, or vice versa), (3) frequency difference of coupled nodes, and (4) an inequality relationship between local and global network properties, which is referred to as the suppressive rule. We observed that the four network conditions for ES were satisfied in the unconscious state. Conditions for ES in the human brain suggest a potential mechanism for rapid recovery from the lightly-anesthetized state. This study demonstrates for the first time that the network conditions for ES, formerly shown in generic networks only, are present in empirically-derived functional brain networks. Further investigations with deep anesthesia, sleep, and coma could provide insight into the underlying causes of variability in recovery profiles of these unconscious states.

Tracking Electroencephalographic Changes Using Distributions of Linear Models: Application to Propofol-Based Depth of Anesthesia Monitoring.

PubMed

Kuhlmann, Levin; Manton, Jonathan H; Heyse, Bjorn; Vereecke, Hugo E M; Lipping, Tarmo; Struys, Michel M R F; Liley, David T J

2017-04-01

Tracking brain states with electrophysiological measurements often relies on short-term averages of extracted features and this may not adequately capture the variability of brain dynamics. The objective is to assess the hypotheses that this can be overcome by tracking distributions of linear models using anesthesia data, and that anesthetic brain state tracking performance of linear models is comparable to that of a high performing depth of anesthesia monitoring feature. Individuals' brain states are classified by comparing the distribution of linear (auto-regressive moving average-ARMA) model parameters estimated from electroencephalographic (EEG) data obtained with a sliding window to distributions of linear model parameters for each brain state. The method is applied to frontal EEG data from 15 subjects undergoing propofol anesthesia and classified by the observers assessment of alertness/sedation (OAA/S) scale. Classification of the OAA/S score was performed using distributions of either ARMA parameters or the benchmark feature, Higuchi fractal dimension. The highest average testing sensitivity of 59% (chance sensitivity: 17%) was found for ARMA (2,1) models and Higuchi fractal dimension achieved 52%, however, no statistical difference was observed. For the same ARMA case, there was no statistical difference if medians are used instead of distributions (sensitivity: 56%). The model-based distribution approach is not necessarily more effective than a median/short-term average approach, however, it performs well compared with a distribution approach based on a high performing anesthesia monitoring measure. These techniques hold potential for anesthesia monitoring and may be generally applicable for tracking brain states.

Intraoperative Frontal Alpha-Band Power Correlates with Preoperative Neurocognitive Function in Older Adults

PubMed Central

Giattino, Charles M.; Gardner, Jacob E.; Sbahi, Faris M.; Roberts, Kenneth C.; Cooter, Mary; Moretti, Eugene; Browndyke, Jeffrey N.; Mathew, Joseph P.; Woldorff, Marty G.; Berger, Miles; Berger, Miles

2017-01-01

Each year over 16 million older Americans undergo general anesthesia for surgery, and up to 40% develop postoperative delirium and/or cognitive dysfunction (POCD). Delirium and POCD are each associated with decreased quality of life, early retirement, increased 1-year mortality, and long-term cognitive decline. Multiple investigators have thus suggested that anesthesia and surgery place severe stress on the aging brain, and that patients with less ability to withstand this stress will be at increased risk for developing postoperative delirium and POCD. Delirium and POCD risk are increased in patients with lower preoperative cognitive function, yet preoperative cognitive function is not routinely assessed, and no intraoperative physiological predictors have been found that correlate with lower preoperative cognitive function. Since general anesthesia causes alpha-band (8–12 Hz) electroencephalogram (EEG) power to decrease occipitally and increase frontally (known as “anteriorization”), and anesthetic-induced frontal alpha power is reduced in older adults, we hypothesized that lower intraoperative frontal alpha power might correlate with lower preoperative cognitive function. Here, we provide evidence that such a correlation exists, suggesting that lower intraoperative frontal alpha power could be used as a physiological marker to identify older adults with lower preoperative cognitive function. Lower intraoperative frontal alpha power could thus be used to target these at-risk patients for possible therapeutic interventions to help prevent postoperative delirium and POCD, or for increased postoperative monitoring and follow-up. More generally, these results suggest that understanding interindividual differences in how the brain responds to anesthetic drugs can be used as a probe of neurocognitive function (and dysfunction), and might be a useful measure of neurocognitive function in older adults. PMID:28533746

Brief anesthesia, but not voluntary locomotion, significantly alters cortical temperature

PubMed Central

Shirey, Michael J.; Kudlik, D'Anne E.; Huo, Bing-Xing; Greene, Stephanie E.; Drew, Patrick J.

2015-01-01

Changes in brain temperature can alter electrical properties of neurons and cause changes in behavior. However, it is not well understood how behaviors, like locomotion, or experimental manipulations, like anesthesia, alter brain temperature. We implanted thermocouples in sensorimotor cortex of mice to understand how cortical temperature was affected by locomotion, as well as by brief and prolonged anesthesia. Voluntary locomotion induced small (∼0.1°C) but reliable increases in cortical temperature that could be described using a linear convolution model. In contrast, brief (90-s) exposure to isoflurane anesthesia depressed cortical temperature by ∼2°C, which lasted for up to 30 min after the cessation of anesthesia. Cortical temperature decreases were not accompanied by a concomitant decrease in the γ-band local field potential power, multiunit firing rate, or locomotion behavior, which all returned to baseline within a few minutes after the cessation of anesthesia. In anesthetized animals where core body temperature was kept constant, cortical temperature was still >1°C lower than in the awake animal. Thermocouples implanted in the subcortex showed similar temperature changes under anesthesia, suggesting these responses occur throughout the brain. Two-photon microscopy of individual blood vessel dynamics following brief isoflurane exposure revealed a large increase in vessel diameter that ceased before the brain temperature significantly decreased, indicating cerebral heat loss was not due to increased cerebral blood vessel dilation. These data should be considered in experimental designs recording in anesthetized preparations, computational models relating temperature and neural activity, and awake-behaving methods that require brief anesthesia before experimental procedures. PMID:25972579

General Anesthesia Inhibits the Activity of the “Glymphatic System”

PubMed Central

Gakuba, Clement; Gaberel, Thomas; Goursaud, Suzanne; Bourges, Jennifer; Di Palma, Camille; Quenault, Aurélien; Martinez de Lizarrondo, Sara; Vivien, Denis; Gauberti, Maxime

2018-01-01

INTRODUCTION: According to the “glymphatic system” hypothesis, brain waste clearance is mediated by a continuous replacement of the interstitial milieu by a bulk flow of cerebrospinal fluid (CSF). Previous reports suggested that this cerebral CSF circulation is only active during general anesthesia or sleep, an effect mediated by the dilatation of the extracellular space. Given the controversies regarding the plausibility of this phenomenon and the limitations of currently available methods to image the glymphatic system, we developed original whole-brain in vivo imaging methods to investigate the effects of general anesthesia on the brain CSF circulation. METHODS: We used magnetic resonance imaging (MRI) and near-infrared fluorescence imaging (NIRF) after injection of a paramagnetic contrast agent or a fluorescent dye in the cisterna magna, in order to investigate the impact of general anesthesia (isoflurane, ketamine or ketamine/xylazine) on the intracranial CSF circulation in mice. RESULTS: In vivo imaging allowed us to image CSF flow in awake and anesthetized mice and confirmed the existence of a brain-wide CSF circulation. Contrary to what was initially thought, we demonstrated that the parenchymal CSF circulation is mainly active during wakefulness and significantly impaired during general anesthesia. This effect was especially significant when high doses of anesthetic agent were used (3% isoflurane). These results were consistent across the different anesthesia regimens and imaging modalities. Moreover, we failed to detect a significant change in the brain extracellular water volume using diffusion weighted imaging in awake and anesthetized mice. CONCLUSION: The parenchymal diffusion of small molecular weight compounds from the CSF is active during wakefulness. General anesthesia has a negative impact on the intracranial CSF circulation, especially when using a high dose of anesthetic agent. PMID:29344300

General Anesthesia Inhibits the Activity of the "Glymphatic System".

PubMed

Gakuba, Clement; Gaberel, Thomas; Goursaud, Suzanne; Bourges, Jennifer; Di Palma, Camille; Quenault, Aurélien; de Lizarrondo, Sara Martinez; Vivien, Denis; Gauberti, Maxime

2018-01-01

INTRODUCTION: According to the "glymphatic system" hypothesis, brain waste clearance is mediated by a continuous replacement of the interstitial milieu by a bulk flow of cerebrospinal fluid (CSF). Previous reports suggested that this cerebral CSF circulation is only active during general anesthesia or sleep, an effect mediated by the dilatation of the extracellular space. Given the controversies regarding the plausibility of this phenomenon and the limitations of currently available methods to image the glymphatic system, we developed original whole-brain in vivo imaging methods to investigate the effects of general anesthesia on the brain CSF circulation. METHODS: We used magnetic resonance imaging (MRI) and near-infrared fluorescence imaging (NIRF) after injection of a paramagnetic contrast agent or a fluorescent dye in the cisterna magna, in order to investigate the impact of general anesthesia (isoflurane, ketamine or ketamine/xylazine) on the intracranial CSF circulation in mice. RESULTS: In vivo imaging allowed us to image CSF flow in awake and anesthetized mice and confirmed the existence of a brain-wide CSF circulation. Contrary to what was initially thought, we demonstrated that the parenchymal CSF circulation is mainly active during wakefulness and significantly impaired during general anesthesia. This effect was especially significant when high doses of anesthetic agent were used (3% isoflurane). These results were consistent across the different anesthesia regimens and imaging modalities. Moreover, we failed to detect a significant change in the brain extracellular water volume using diffusion weighted imaging in awake and anesthetized mice. CONCLUSION: The parenchymal diffusion of small molecular weight compounds from the CSF is active during wakefulness. General anesthesia has a negative impact on the intracranial CSF circulation, especially when using a high dose of anesthetic agent.

Neural correlates of consciousness during general anesthesia using functional magnetic resonance imaging (fMRI).

PubMed

Bonhomme, V; Boveroux, P; Brichant, J F; Laureys, S; Boly, M

2012-01-01

This paper reviews the current knowledge about the mechanisms of anesthesia-induced alteration of consciousness. It is now evident that hypnotic anesthetic agents have specific brain targets whose function is hierarchically altered in a dose-dependent manner. Higher order networks, thought to be involved in mental content generation, as well as sub-cortical networks involved in thalamic activity regulation seems to be affected first by increasing concentrations of hypnotic agents that enhance inhibitory neurotransmission. Lower order sensory networks are preserved, including thalamo-cortical connectivity into those networks, even at concentrations that suppress responsiveness, but cross-modal sensory interactions are inhibited. Thalamo-cortical connectivity into the consciousness networks decreases with increasing concentrations of those agents, and is transformed into an anti-correlated activity between the thalamus and the cortex for the deepest levels of sedation, when the subject is non responsive. Future will tell us whether these brain function alterations are also observed with hypnotic agents that mainly inhibit excitatory neurotransmission. The link between the observations made using fMRI and the identified biochemical targets of hypnotic anesthetic agents still remains to be identified.

Neurodegeneration in newborn rats following propofol and sevoflurane anesthesia.

PubMed

Bercker, Sven; Bert, Bettina; Bittigau, Petra; Felderhoff-Müser, Ursula; Bührer, Christoph; Ikonomidou, Chrysanthy; Weise, Mirjam; Kaisers, Udo X; Kerner, Thoralf

2009-08-01

Propofol and sevoflurane are commonly used drugs in pediatric anesthesia. Exposure of newborn rats to a variety of anesthetics has been shown to induce apoptotic neurodegeneration in the developing brain. Newborn Wistar rats were treated with repeated intraperitoneal injections of propofol or sevoflurane inhalation and compared to controls. Brains were examined histopathologically using the De Olmos cupric silver staining. Additionally, a summation score of the density of apoptotic cells was calculated for every brain. Spatial memory learning was assessed by the Morris Water Maze (MWM) test and the hole board test, performed in 7 weeks old animals who underwent the same anesthetic procedure. Brains of propofol-treated animals showed a significant higher neurodegenerative summation score (24,345) when compared to controls (15,872) and to sevoflurane-treated animals (18,870). Treated animals also demonstrated persistent learning deficits in the hole board test, whereas the MWM test revealed no differences between both groups. Among other substances acting via GABAA agonism and/or NMDA antagonism propofol induced neurodegeneration in newborn rat brains whereas a sevoflurane based anesthesia did not. The significance of these results for clinical anesthesia has not been completely elucidated. Future studies have to focus on the detection of safe anesthetic strategies for the developing brain.

The right thalamus may play an important role in anesthesia-awakening regulation in frogs

PubMed Central

Fan, Yanzhu; Yue, Xizi; Xue, Fei; Brauth, Steven E.; Tang, Yezhong

2018-01-01

Background Previous studies have shown that the mammalian thalamus is a key structure for anesthesia-induced unconsciousness and anesthesia-awakening regulation. However, both the dynamic characteristics and probable lateralization of thalamic functioning during anesthesia-awakening regulation are not fully understood, and little is known of the evolutionary basis of the role of the thalamus in anesthesia-awakening regulation. Methods An amphibian species, the South African clawed frog (Xenopus laevis) was used in the present study. The frogs were immersed in triciane methanesulfonate (MS-222) for general anesthesia. Electroencephalogram (EEG) signals were recorded continuously from both sides of the telencephalon, diencephalon (thalamus) and mesencephalon during the pre-anesthesia stage, administration stage, recovery stage and post-anesthesia stage. EEG data was analyzed including calculation of approximate entropy (ApEn) and permutation entropy (PE). Results Both ApEn and PE values differed significantly between anesthesia stages, with the highest values occurring during the awakening period and the lowest values during the anesthesia period. There was a significant correlation between the stage durations and ApEn or PE values during anesthesia-awakening cycle primarily for the right diencephalon (right thalamus). ApEn and PE values for females were significantly higher than those for males. Discussion ApEn and PE measurements are suitable for estimating depth of anesthesia and complexity of amphibian brain activity. The right thalamus appears physiologically positioned to play an important role in anesthesia-awakening regulation in frogs indicating an early evolutionary origin of the role of the thalamus in arousal and consciousness in land vertebrates. Sex differences exist in the neural regulation of general anesthesia in frogs. PMID:29576980

Awake vs. anesthetized: layer-specific sensory processing in visual cortex and functional connectivity between cortical areas

PubMed Central

Sellers, Kristin K.; Bennett, Davis V.; Hutt, Axel; Williams, James H.

2015-01-01

During general anesthesia, global brain activity and behavioral state are profoundly altered. Yet it remains mostly unknown how anesthetics alter sensory processing across cortical layers and modulate functional cortico-cortical connectivity. To address this gap in knowledge of the micro- and mesoscale effects of anesthetics on sensory processing in the cortical microcircuit, we recorded multiunit activity and local field potential in awake and anesthetized ferrets (Mustela putoris furo) during sensory stimulation. To understand how anesthetics alter sensory processing in a primary sensory area and the representation of sensory input in higher-order association areas, we studied the local sensory responses and long-range functional connectivity of primary visual cortex (V1) and prefrontal cortex (PFC). Isoflurane combined with xylazine provided general anesthesia for all anesthetized recordings. We found that anesthetics altered the duration of sensory-evoked responses, disrupted the response dynamics across cortical layers, suppressed both multimodal interactions in V1 and sensory responses in PFC, and reduced functional cortico-cortical connectivity between V1 and PFC. Together, the present findings demonstrate altered sensory responses and impaired functional network connectivity during anesthesia at the level of multiunit activity and local field potential across cortical layers. PMID:25833839

Long-lasting behavioral effects in neonatal mice with multiple exposures to ketamine-xylazine anesthesia

PubMed Central

Huang, Lianyan; Hayes, Scott; Yang, Guang

2016-01-01

Anesthetic agents are often administered in the neonatal period, a time of rapid brain development and synaptogenesis. Mounting evidence suggests that anesthetics can disrupt neurocognitive development, particularly in cases of multiple or prolonged anesthetic exposure. Previous studies have shown that administering multiple doses of ketamine-xylazine (KX) anesthesia to neonatal mice can induce long-term changes to synaptic plasticity in the cortex, but the effect on neurocognitive function remains unclear. In this study, we exposed neonatal mice to single dose and multiple doses of KX anesthesia in the neonatal period (postnatal days 7, 9, 11), and conducted a series of behavioral tests in young adulthood (1 month of age). Mice receiving multiple doses of KX anesthesia showed deficits in novel object recognition, sociability, preference for social novelty and contextual fear response, but no effect on auditory-cued fear response. Single dose of KX anesthesia had no effect on these behaviors except for contextual fear response. We also observed that multiple exposures to KX anesthesia were associated with decreased CaMKII phosphorylation, which is known to play a role in synapse development and long-term potentiation, likely contributing to learning impairment. PMID:27622724

Permutation auto-mutual information of electroencephalogram in anesthesia

NASA Astrophysics Data System (ADS)

Liang, Zhenhu; Wang, Yinghua; Ouyang, Gaoxiang; Voss, Logan J.; Sleigh, Jamie W.; Li, Xiaoli

2013-04-01

Objective. The dynamic change of brain activity in anesthesia is an interesting topic for clinical doctors and drug designers. To explore the dynamical features of brain activity in anesthesia, a permutation auto-mutual information (PAMI) method is proposed to measure the information coupling of electroencephalogram (EEG) time series obtained in anesthesia. Approach. The PAMI is developed and applied on EEG data collected from 19 patients under sevoflurane anesthesia. The results are compared with the traditional auto-mutual information (AMI), SynchFastSlow (SFS, derived from the BIS index), permutation entropy (PE), composite PE (CPE), response entropy (RE) and state entropy (SE). Performance of all indices is assessed by pharmacokinetic/pharmacodynamic (PK/PD) modeling and prediction probability. Main results. The PK/PD modeling and prediction probability analysis show that the PAMI index correlates closely with the anesthetic effect. The coefficient of determination R2 between PAMI values and the sevoflurane effect site concentrations, and the prediction probability Pk are higher in comparison with other indices. The information coupling in EEG series can be applied to indicate the effect of the anesthetic drug sevoflurane on the brain activity as well as other indices. The PAMI of the EEG signals is suggested as a new index to track drug concentration change. Significance. The PAMI is a useful index for analyzing the EEG dynamics during general anesthesia.

Brain Connectivity in Pathological and Pharmacological Coma

PubMed Central

Noirhomme, Quentin; Soddu, Andrea; Lehembre, Rémy; Vanhaudenhuyse, Audrey; Boveroux, Pierre; Boly, Mélanie; Laureys, Steven

2010-01-01

Recent studies in patients with disorders of consciousness (DOC) tend to support the view that awareness is not related to activity in a single brain region but to thalamo-cortical connectivity in the frontoparietal network. Functional neuroimaging studies have shown preserved albeit disconnected low-level cortical activation in response to external stimulation in patients in a “vegetative state” or unresponsive wakefulness syndrome. While activation of these “primary” sensory cortices does not necessarily reflect conscious awareness, activation in higher-order associative cortices in minimally conscious state patients seems to herald some residual perceptual awareness. PET studies have identified a metabolic dysfunction in a widespread frontoparietal “global neuronal workspace” in DOC patients including the midline default mode network (“intrinsic” system) and the lateral frontoparietal cortices or “extrinsic system.” Recent studies have investigated the relation of awareness to the functional connectivity within intrinsic and extrinsic networks, and with the thalami in both pathological and pharmacological coma. In brain damaged patients, connectivity in all default network areas was found to be non-linearly correlated with the degree of clinical consciousness impairment, ranging from healthy controls and locked-in syndrome to minimally conscious, vegetative, coma, and brain dead patients. Anesthesia-induced loss of consciousness was also shown to correlate with a global decrease in cortico-cortical and thalamo-cortical connectivity in both intrinsic and extrinsic networks, but not in auditory, or visual networks. In anesthesia, unconsciousness was also associated with a loss of cross-modal interactions between networks. These results suggest that conscious awareness critically depends on the functional integrity of thalamo-cortical and cortico-cortical frontoparietal connectivity within and between “intrinsic” and “extrinsic” brain networks. PMID:21191476

Role of Network Science in the Study of Anesthetic State Transitions.

PubMed

Lee, UnCheol; Mashour, George A

2018-04-23

The heterogeneity of molecular mechanisms, target neural circuits, and neurophysiologic effects of general anesthetics makes it difficult to develop a reliable and drug-invariant index of general anesthesia. No single brain region or mechanism has been identified as the neural correlate of consciousness, suggesting that consciousness might emerge through complex interactions of spatially and temporally distributed brain functions. The goal of this review article is to introduce the basic concepts of networks and explain why the application of network science to general anesthesia could be a pathway to discover a fundamental mechanism of anesthetic-induced unconsciousness. This article reviews data suggesting that reduced network efficiency, constrained network repertoires, and changes in cortical dynamics create inhospitable conditions for information processing and transfer, which lead to unconsciousness. This review proposes that network science is not just a useful tool but a necessary theoretical framework and method to uncover common principles of anesthetic-induced unconsciousness.

Prospective study of awake craniotomy used routinely and nonselectively for supratentorial tumors.

PubMed

Serletis, Demitre; Bernstein, Mark

2007-07-01

The authors prospectively assessed the value of awake craniotomy used nonselectively in patients undergoing resection of supratentorial tumors. The demographic features, presenting symptoms, tumor location, histological diagnosis, outcomes, and complications were documented for 610 patients who underwent awake craniotomy for supratentorial tumor resection. Intraoperative brain mapping was used in 511 cases (83.8%). Mapping identified eloquent cortex in 115 patients (22.5%) and no eloquent cortex in 396 patients (77.5%). Neurological deficits occurred in 89 patients (14.6%). In the subset of 511 patients in whom brain mapping was performed, 78 (15.3%) experienced postoperative neurological worsening. This phenomenon was more common in patients with preoperative neurological deficits or in those individuals in whom mapping successfully identified eloquent tissue. Twenty-five (4.9%) of the 511 patients suffered intraoperative seizures, and two of these individuals required intubation and induction of general anesthesia after generalized seizures occurred. Four (0.7%) of the 610 patients developed wound complications. Postoperative hematomas developed in seven patients (1.1%), four of whom urgently required a repeated craniotomy to allow evacuation of the clot. Two patients (0.3%) required readmission to the hospital soon after being discharged. There were three deaths (0.5%). Awake craniotomy is safe, practical, and effective during resection of supratentorial lesions of diverse pathological range and location. It allows for intraoperative brain mapping that helps identify and protect functional cortex. It also avoids the complications inherent in the induction of general anesthesia. Awake craniotomy provides an excellent alternative to surgery of supratentorial brain lesions in patients in whom general anesthesia has been induced.

Temperature control can abolish anesthesia-induced tau hyperphosphorylation and partly reverse anesthesia-induced cognitive impairment in old mice.

PubMed

Xiao, Haibing; Run, Xiaoqin; Cao, Xu; Su, Ying; Sun, Zhou; Tian, Cheng; Sun, Shenggang; Liang, Zhihou

2013-11-01

Anesthesia is related to cognitive impairment and the risk for Alzheimer's disease. Hypothermia during anesthesia can lead to abnormal hyperphosphorylation of tau, which has been speculated to be involved in anesthesia-induced cognitive impairment. The aim of this study was to investigate whether maintenance of the tau phosphorylation level by body temperature control during anesthesia could reverse the cognitive dysfunction in C57BL/6 mice. Eighteen-month-old mice were repeatedly anesthetized during a 2-week period with or without maintenance of body temperature, control mice were treated with normal saline instead of anesthetics. Tau phosphorylation level in mice brain was detected on western blot, and cognitive performance was measured using the Morris water maze (MWM). After anesthesia-induced hypothermia in old mice, tau was hyperphosphorylated and the cognitive performance, measured on MWM, was impaired. When body temperature was controlled during anesthesia, however, the tau hyperphosphorylation was completely avoided, and there was partial recovery in cognitive impairment measured on the MWM. Hyperphosphorylation of tau in the brain after anesthesia is an important event, and it might be, although not solely, responsible for postoperative cognitive decline. © 2013 The Authors. Psychiatry and Clinical Neurosciences © 2013 Japanese Society of Psychiatry and Neurology.

Conversion of elderly to Alzheimer's dementia: role of confluence of hypothermia and senescent stigmata--the plausible pathway.

PubMed

Daulatzai, Mak Adam

2010-01-01

Aging is a consequence of progressive decline in special and somatosensory functions and specific brain stem nuclei. Many senescent stigmata, including hypoxia, hypoxemia, depressed cerebral blood flow and glucose metabolism, diseases of senescence, and their medications all enhance hypothermia as do alcohol, cold environment, and malnutrition. Hypothermia is a critical factor having deleterious impact on brain stem and neocortical functions. Additionally, anesthesia in elderly also promotes hypothermia; anesthetics not only cause consciousness (sensory and motor) changes, but memory impairment as well. Anesthesia inhibits cholinergic pathways, reticular and thalamocortical systems, cortico-cortical connectivity, and causes post-operative delirium and cognitive dysfunction. Increasing evidence indicates that anesthetic exposures may contribute to dementia onset and Alzheimer's disease (AD) in hypothermic elderly. Inhaled anesthetics potentiate caspases, BACE, tau hyperphosphorylation, and apoptosis. This paper addresses the important question: "Why do only some elderly fall victim to AD"? Based on information on the pathogenesis of early stages of cognitive dysfunction in elderly (i.e., due to senescent stigmata), and the effects of anesthesia superimposed, a detailed plausible neuropathological substrate (mechanism/pathway) is delineated here that reveals the possible cause(s) of AD. Basically, it encompasses several risk factors for cognitive dysfunction during senescence plus several hypothermia-enhancing routes; they all converge and tip the balance towards dementia onset. This knowledge of the confluence of heterogeneous risk factors in perpetuating dementia relentlessly is of importance in order to: (a) avoid their convergence; (b) take measures to stop/reverse cognitive dysfunction; and (c) to develop therapeutic strategies to enhance cognitive function and attenuate AD.

Breakdown of long-range temporal correlations in brain oscillations during general anesthesia.

PubMed

Krzemiński, Dominik; Kamiński, Maciej; Marchewka, Artur; Bola, Michał

2017-10-01

Consciousness has been hypothesized to emerge from complex neuronal dynamics, which prevails when brain operates in a critical state. Evidence supporting this hypothesis comes mainly from studies investigating neuronal activity on a short time-scale of seconds. However, a key aspect of criticality is presence of scale-free temporal dependencies occurring across a wide range of time-scales. Indeed, robust long-range temporal correlations (LRTCs) are found in neuronal oscillations during conscious states, but it is not known how LRTCs are affected by loss of consciousness. To further test a relation between critical dynamics and consciousness, we investigated LRTCs in electrocorticography signals recorded from four macaque monkeys during resting wakefulness and general anesthesia induced by various anesthetics (ketamine, medetomidine, or propofol). Detrended Fluctuation Analysis was used to estimate LRTCs in amplitude fluctuations (envelopes) of band-pass filtered signals. We demonstrate two main findings. First, during conscious states all lateral cortical regions are characterized by significant LRTCs of alpha-band activity (7-14 Hz). LRTCs are stronger in the eyes-open than eyes-closed state, but in both states they form a spatial gradient, with anterior brain regions exhibiting stronger LRTCs than posterior regions. Second, we observed a substantial decrease of LRTCs during loss of consciousness, the magnitude of which was associated with the baseline (i.e. pre-anesthesia) state of the brain. Specifically, brain regions characterized by strongest LRTCs during a wakeful baseline exhibited greatest decreases during anesthesia (i.e. "the rich got poorer"), which consequently disturbed the posterior-anterior gradient. Therefore, our results suggest that general anesthesia affects mainly brain areas characterized by strongest LRTCs during wakefulness, which might account for lack of capacities for extensive temporal integration during loss of consciousness. Copyright © 2017 Elsevier Inc. All rights reserved.

The effects of neonatal isoflurane exposure in mice on brain cell viability, adult behavior, learning, and memory.

PubMed

Loepke, Andreas W; Istaphanous, George K; McAuliffe, John J; Miles, Lili; Hughes, Elizabeth A; McCann, John C; Harlow, Kathryn E; Kurth, C Dean; Williams, Michael T; Vorhees, Charles V; Danzer, Steve C

2009-01-01

Volatile anesthetics, such as isoflurane, are widely used in infants and neonates. Neurodegeneration and neurocognitive impairment after exposure to isoflurane, midazolam, and nitrous oxide in neonatal rats have raised concerns regarding the safety of pediatric anesthesia. In neonatal mice, prolonged isoflurane exposure triggers hypoglycemia, which could be responsible for the neurocognitive impairment. We examined the effects of neonatal isoflurane exposure and blood glucose on brain cell viability, spontaneous locomotor activity, as well as spatial learning and memory in mice. Seven-day-old mice were randomly assigned to 6 h of 1.5% isoflurane with or without injections of dextrose or normal saline, or to 6 h of room air without injections (no anesthesia). Arterial blood gases and glucose were measured. After 2 h, 18 h, or 11 wk postexposure, cellular viability was assessed in brain sections stained with Fluoro-Jade B, caspase 3, or NeuN. Nine weeks postexposure, spontaneous locomotor activity was assessed, and spatial learning and memory were evaluated in the Morris water maze using hidden and reduced platform trials. Apoptotic cellular degeneration increased in several brain regions early after isoflurane exposure, compared with no anesthesia. Despite neonatal cell loss, however, adult neuronal density was unaltered in two brain regions significantly affected by the neonatal degeneration. In adulthood, spontaneous locomotor activity and spatial learning and memory performance were similar in all groups, regardless of neonatal isoflurane exposure. Neonatal isoflurane exposure led to an 18% mortality, and transiently increased Paco(2), lactate, and base deficit, and decreased blood glucose levels. However, hypoglycemia did not seem responsible for the neurodegeneration, as dextrose supplementation failed to prevent neuronal loss. Prolonged isoflurane exposure in neonatal mice led to increased immediate brain cell degeneration, however, no significant reductions in adult neuronal density or deficits in spontaneous locomotion, spatial learning, or memory function were observed.

Long-term Fate Mapping to Assess the Impact of Postnatal Isoflurane Exposure on Hippocampal Progenitor Cell Productivity.

PubMed

Jiang, Yifei; Tong, Dongyi; Hofacer, Rylon D; Loepke, Andreas W; Lian, Qingquan; Danzer, Steve C

2016-12-01

Exposure to isoflurane increases apoptosis among postnatally generated hippocampal dentate granule cells. These neurons play important roles in cognition and behavior, so their permanent loss could explain deficits after surgical procedures. To determine whether developmental anesthesia exposure leads to persistent deficits in granule cell numbers, a genetic fate-mapping approach to label a cohort of postnatally generated granule cells in Gli1-CreER::GFP bitransgenic mice was utilized. Green fluorescent protein (GFP) expression was induced on postnatal day 7 (P7) to fate map progenitor cells, and mice were exposed to 6 h of 1.5% isoflurane or room air 2 weeks later (P21). Brain structure was assessed immediately after anesthesia exposure (n = 7 controls and 8 anesthesia-treated mice) or after a 60-day recovery (n = 8 controls and 8 anesthesia-treated mice). A final group of C57BL/6 mice was exposed to isoflurane at P21 and examined using neurogenesis and cell death markers after a 14-day recovery (n = 10 controls and 16 anesthesia-treated mice). Isoflurane significantly increased apoptosis immediately after exposure, leading to cell death among 11% of GFP-labeled cells. Sixty days after isoflurane exposure, the number of GFP-expressing granule cells in treated animals was indistinguishable from control animals. Rates of neurogenesis were equivalent among groups at both 2 weeks and 2 months after treatment. These findings suggest that the dentate gyrus can restore normal neuron numbers after a single, developmental exposure to isoflurane. The authors' results do not preclude the possibility that the affected population may exhibit more subtle structural or functional deficits. Nonetheless, the dentate appears to exhibit greater resiliency relative to nonneurogenic brain regions, which exhibit permanent neuron loss after isoflurane exposure.

A transition in brain state during propofol-induced unconsciousness.

PubMed

Mukamel, Eran A; Pirondini, Elvira; Babadi, Behtash; Wong, Kin Foon Kevin; Pierce, Eric T; Harrell, P Grace; Walsh, John L; Salazar-Gomez, Andres F; Cash, Sydney S; Eskandar, Emad N; Weiner, Veronica S; Brown, Emery N; Purdon, Patrick L

2014-01-15

Rhythmic oscillations shape cortical dynamics during active behavior, sleep, and general anesthesia. Cross-frequency phase-amplitude coupling is a prominent feature of cortical oscillations, but its role in organizing conscious and unconscious brain states is poorly understood. Using high-density EEG and intracranial electrocorticography during gradual induction of propofol general anesthesia in humans, we discovered a rapid drug-induced transition between distinct states with opposite phase-amplitude coupling and different cortical source distributions. One state occurs during unconsciousness and may be similar to sleep slow oscillations. A second state occurs at the loss or recovery of consciousness and resembles an enhanced slow cortical potential. These results provide objective electrophysiological landmarks of distinct unconscious brain states, and could be used to help improve EEG-based monitoring for general anesthesia.

Dexmedetomidine Prevents Excessive γ-Aminobutyric Acid Type A Receptor Function after Anesthesia.

PubMed

Wang, Dian-Shi; Kaneshwaran, Kirusanthy; Lei, Gang; Mostafa, Fariya; Wang, Junhui; Lecker, Irene; Avramescu, Sinziana; Xie, Yu-Feng; Chan, Nathan K; Fernandez-Escobar, Alejandro; Woo, Junsung; Chan, Darren; Ramsey, Amy J; Sivak, Jeremy M; Lee, C Justin; Bonin, Robert P; Orser, Beverley A

2018-06-08

Postoperative delirium is associated with poor long-term outcomes and increased mortality. General anesthetic drugs may contribute to delirium because they increase cell-surface expression and function of α5 subunit-containing γ-aminobutyric acid type A receptors, an effect that persists long after the drugs have been eliminated. Dexmedetomidine, an α2 adrenergic receptor agonist, prevents delirium in patients and reduces cognitive deficits in animals. Thus, it was postulated that dexmedetomidine prevents excessive function of α5 γ-aminobutyric acid type A receptors. Injectable (etomidate) and inhaled (sevoflurane) anesthetic drugs were studied using cultured murine hippocampal neurons, cultured murine and human cortical astrocytes, and ex vivo murine hippocampal slices. γ-Aminobutyric acid type A receptor function and cell-signaling pathways were studied using electrophysiologic and biochemical methods. Memory and problem-solving behaviors were also studied. The etomidate-induced sustained increase in α5 γ-aminobutyric acid type A receptor cell-surface expression was reduced by dexmedetomidine (mean ± SD, etomidate: 146.4 ± 51.6% vs. etomidate + dexmedetomidine: 118.4 ± 39.1% of control, n = 8 each). Dexmedetomidine also reduced the persistent increase in tonic inhibitory current in hippocampal neurons (etomidate: 1.44 ± 0.33 pA/pF, n = 10; etomidate + dexmedetomidine: 1.01 ± 0.45 pA/pF, n = 9). Similarly, dexmedetomidine prevented a sevoflurane-induced increase in the tonic current. Dexmedetomidine stimulated astrocytes to release brain-derived neurotrophic factor, which acted as a paracrine factor to reduce excessive α5 γ-aminobutyric acid type A receptor function in neurons. Finally, dexmedetomidine attenuated memory and problem-solving deficits after anesthesia. Dexmedetomidine prevented excessive α5 γ-aminobutyric acid type A receptor function after anesthesia. This novel α2 adrenergic receptor- and brain-derived neurotrophic factor-dependent pathway may be targeted to prevent delirium.

Acceleration and persistence of neurofibrillary pathology in a mouse model of tauopathy following anesthesia

PubMed Central

Planel, Emmanuel; Bretteville, Alexis; Liu, Li; Virag, Laszlo; Du, Angela L.; Yu, Wai Haung; Dickson, Dennis W.; Whittington, Robert A.; Duff, Karen E.

2009-01-01

Alzheimer’s disease and other tauopathies are characterized by the presence of intracellular neurofibrillary tangles composed of hyperphosphorylated, insoluble tau. General anesthesia has been shown to be associated with increased risk of Alzheimer’s disease, and we have previously demonstrated that anesthesia induces hypothermia, which leads to overt tau hyperphosphorylation in the brain of mice regardless of the anesthetic used. To investigate whether anesthesia enhances the long-term risk of developing pathological forms of tau, we exposed a mouse model with tauopathy to anesthesia and monitored the outcome at two time points—during anesthesia, or 1 wk after exposure. We found that exposure to isoflurane at clinically relevant doses led to increased levels of phospho-tau, increased insoluble, aggregated forms of tau, and detachment of tau from microtubules. Furthermore, levels of phospho-tau distributed in the neuropil, as well as in cell bodies increased. Interestingly, the level of insoluble tau was increased 1 wk following anesthesia, suggesting that anesthesia precipitates changes in the brain that provoke the later development of tauopathy. Overall, our results suggest that anesthesia-induced hypothermia could lead to an acceleration of tau pathology in vivo that could have significant clinical implications for patients with early stage, or overt neurofibrillary tangle pathology.—Planel, E., Bretteville, A., Liu, L., Virag, L., Du, A. L., Yu, W. Y., Dickson, D. W., Whittington, R. A., Duff, K. E. Acceleration and persistence of neurofibrillary pathology in a mouse model of tauopathy following anesthesia. PMID:19279139

Local Versus Global Effects of Isoflurane Anesthesia on Visual Processing in the Fly Brain

PubMed Central

2016-01-01

Abstract What characteristics of neural activity distinguish the awake and anesthetized brain? Drugs such as isoflurane abolish behavioral responsiveness in all animals, implying evolutionarily conserved mechanisms. However, it is unclear whether this conservation is reflected at the level of neural activity. Studies in humans have shown that anesthesia is characterized by spatially distinct spectral and coherence signatures that have also been implicated in the global impairment of cortical communication. We questioned whether anesthesia has similar effects on global and local neural processing in one of the smallest brains, that of the fruit fly (Drosophila melanogaster). Using a recently developed multielectrode technique, we recorded local field potentials from different areas of the fly brain simultaneously, while manipulating the concentration of isoflurane. Flickering visual stimuli (‘frequency tags’) allowed us to track evoked responses in the frequency domain and measure the effects of isoflurane throughout the brain. We found that isoflurane reduced power and coherence at the tagging frequency (13 or 17 Hz) in central brain regions. Unexpectedly, isoflurane increased power and coherence at twice the tag frequency (26 or 34 Hz) in the optic lobes of the fly, but only for specific stimulus configurations. By modeling the periodic responses, we show that the increase in power in peripheral areas can be attributed to local neuroanatomy. We further show that the effects on coherence can be explained by impacted signal-to-noise ratios. Together, our results show that general anesthesia has distinct local and global effects on neuronal processing in the fruit fly brain. PMID:27517084

Local Versus Global Effects of Isoflurane Anesthesia on Visual Processing in the Fly Brain.

PubMed

Cohen, Dror; Zalucki, Oressia H; van Swinderen, Bruno; Tsuchiya, Naotsugu

2016-01-01

What characteristics of neural activity distinguish the awake and anesthetized brain? Drugs such as isoflurane abolish behavioral responsiveness in all animals, implying evolutionarily conserved mechanisms. However, it is unclear whether this conservation is reflected at the level of neural activity. Studies in humans have shown that anesthesia is characterized by spatially distinct spectral and coherence signatures that have also been implicated in the global impairment of cortical communication. We questioned whether anesthesia has similar effects on global and local neural processing in one of the smallest brains, that of the fruit fly (Drosophila melanogaster). Using a recently developed multielectrode technique, we recorded local field potentials from different areas of the fly brain simultaneously, while manipulating the concentration of isoflurane. Flickering visual stimuli ('frequency tags') allowed us to track evoked responses in the frequency domain and measure the effects of isoflurane throughout the brain. We found that isoflurane reduced power and coherence at the tagging frequency (13 or 17 Hz) in central brain regions. Unexpectedly, isoflurane increased power and coherence at twice the tag frequency (26 or 34 Hz) in the optic lobes of the fly, but only for specific stimulus configurations. By modeling the periodic responses, we show that the increase in power in peripheral areas can be attributed to local neuroanatomy. We further show that the effects on coherence can be explained by impacted signal-to-noise ratios. Together, our results show that general anesthesia has distinct local and global effects on neuronal processing in the fruit fly brain.

[The glymphatic system: concept, function and research progresses].

PubMed

Wang, Lin-Hui; Wang, Zi-Lan; Chen, Wen-Yue; Chen, Ming-Jia; Xu, Guang-Yin

2018-02-25

The glymphatic system is a cerebrospinal fluid-interstitial fluid exchange system dependent on the water channel aquaporin-4 polarized on astrocyte endfeet, which is proposed to account for the clearance of abnormal proteins (e.g. β-amyloid) and metabolites (e.g. lactate) from the brain. Accumulating studies have revealed that glymphatic activity during sleep and general anesthesia is dramatically enhanced, while its function is significantly damaged during aging, traumatic brain injury, Alzheimer's disease, stroke, and diabetes. The glymphatic hypothesis is a breakthrough in the field of neuroscience recently, which would considerably enhance our comprehension on the cerebrospinal fluid circulation and its role in the maintenance of brain homeostasis. In this review, we briefly introduced the conceptualization of glymphatic system, summarized the recent progresses, and prospected its future investigation and potential clinical application.

Tracking brain states under general anesthesia by using global coherence analysis.

PubMed

Cimenser, Aylin; Purdon, Patrick L; Pierce, Eric T; Walsh, John L; Salazar-Gomez, Andres F; Harrell, Priscilla G; Tavares-Stoeckel, Casie; Habeeb, Kathleen; Brown, Emery N

2011-05-24

Time and frequency domain analyses of scalp EEG recordings are widely used to track changes in brain states under general anesthesia. Although these analyses have suggested that different spatial patterns are associated with changes in the state of general anesthesia, the extent to which these patterns are spatially coordinated has not been systematically characterized. Global coherence, the ratio of the largest eigenvalue to the sum of the eigenvalues of the cross-spectral matrix at a given frequency and time, has been used to analyze the spatiotemporal dynamics of multivariate time-series. Using 64-lead EEG recorded from human subjects receiving computer-controlled infusions of the anesthetic propofol, we used surface Laplacian referencing combined with spectral and global coherence analyses to track the spatiotemporal dynamics of the brain's anesthetic state. During unconsciousness the spectrograms in the frontal leads showed increasing α (8-12 Hz) and δ power (0-4 Hz) and in the occipital leads δ power greater than α power. The global coherence detected strong coordinated α activity in the occipital leads in the awake state that shifted to the frontal leads during unconsciousness. It revealed a lack of coordinated δ activity during both the awake and unconscious states. Although strong frontal power during general anesthesia-induced unconsciousness--termed anteriorization--is well known, its possible association with strong α range global coherence suggests highly coordinated spatial activity. Our findings suggest that combined spectral and global coherence analyses may offer a new approach to tracking brain states under general anesthesia.

Brain Network Architecture and Global Intelligence in Children with Focal Epilepsy.

PubMed

Paldino, M J; Golriz, F; Chapieski, M L; Zhang, W; Chu, Z D

2017-02-01

The biologic basis for intelligence rests to a large degree on the capacity for efficient integration of information across the cerebral network. We aimed to measure the relationship between network architecture and intelligence in the pediatric, epileptic brain. Patients were retrospectively identified with the following: 1) focal epilepsy; 2) brain MR imaging at 3T, including resting-state functional MR imaging; and 3) full-scale intelligence quotient measured by a pediatric neuropsychologist. The cerebral cortex was parcellated into approximately 700 gray matter network "nodes." The strength of a connection between 2 nodes was defined by the correlation between their blood oxygen level-dependent time-series. We calculated the following topologic properties: clustering coefficient, transitivity, modularity, path length, and global efficiency. A machine learning algorithm was used to measure the independent contribution of each metric to the intelligence quotient after adjusting for all other metrics. Thirty patients met the criteria (4-18 years of age); 20 patients required anesthesia during MR imaging. After we accounted for age and sex, clustering coefficient and path length were independently associated with full-scale intelligence quotient. Neither motion parameters nor general anesthesia was an important variable with regard to accurate intelligence quotient prediction by the machine learning algorithm. A longer history of epilepsy was associated with shorter path lengths ( P = .008), consistent with reorganization of the network on the basis of seizures. Considering only patients receiving anesthesia during machine learning did not alter the patterns of network architecture contributing to global intelligence. These findings support the physiologic relevance of imaging-based metrics of network architecture in the pathologic, developing brain. © 2017 by American Journal of Neuroradiology.

Hypotensive Anesthesia versus Normotensive Anesthesia during Major Maxillofacial Surgery: A Review of the Literature

PubMed Central

Yoav, Leiser; Abu el-Naaj, Imad

2015-01-01

Steady blood pressure within normal limits during surgery is one of the markers of the ideal and skillful anesthesia. Yet, reduced blood pressure is advantageous in some settings because it can contribute to a reduction in overall blood loss and improve the surgical field conditions. Controlled hypotension during anesthesia or hypotensive anesthesia is often used in major maxillofacial operations. Since hypotensive anesthesia carries the risk of hypoperfusion to important organs and tissues, mainly the brain, heart, and kidneys, it cannot be applied safely in all patients. In this paper we review the medical literature regarding hypotensive anesthesia during major maxillofacial surgery, the means to achieve it, and the risks and benefits of this technique, in comparison to normotensive anesthesia. PMID:25811042

Postoperative Structural Brain Changes and Cognitive Dysfunction in Patients with Breast Cancer.

PubMed

Sato, Chiho; Sekiguchi, Atsushi; Kawai, Masaaki; Kotozaki, Yuka; Nouchi, Rui; Tada, Hiroshi; Takeuchi, Hikaru; Ishida, Takanori; Taki, Yasuyuki; Kawashima, Ryuta; Ohuchi, Noriaki

2015-01-01

The primary purpose of this study was to clarify the influence of the early response to surgery on brain structure and cognitive function in patients with breast cancer. It was hypothesized that the structure of the thalamus would change during the early response after surgery due to the effects of anesthesia and would represent one aspect of an intermediate phenotype of postoperative cognitive dysfunction (POCD). We examined 32 postmenopausal females with breast cancer and 20 age-matched controls. We assessed their cognitive function (attention, memory, and executive function), and performed brain structural MRI 1.5 ± 0.5 days before and 5.6 ± 1.2 days after surgery. We found a significant interaction between regional grey matter volume (rGMV) in the thalamus (P < 0.05, familywise error (FWE), small volume correction (SVC)) and one attention domain subtest (P = 0.001, Bonferroni correction) after surgery in the patient group compared with the control group. Furthermore, the changes in attention were significantly associated with sevoflurane anesthetic dose (r2 = 0.247, β = ‒0.471, P = 0.032) and marginally associated with rGMV changes in the thalamus (P = 0.07, FWE, SVC) in the Pt group. Our findings suggest that alterations in brain structure, particularly in the thalamus, may occur shortly after surgery and may be associated with attentional dysfunction. This early postoperative response to anesthesia may represent an intermediate phenotype of POCD. It was assumed that patients experiencing other risk factors of POCD, such as the severity of surgery, the occurrence of complications, and pre-existing cognitive impairments, would develop clinical POCD with broad and multiple types of cognitive dysfunction.

Anesthetic Sevoflurane Causes Neurotoxicity Differently in Neonatal Naïve and Alzheimer's Disease Transgenic Mice

PubMed Central

Lu, Yan; Wu, Xu; Dong, Yuanlin; Xu, Zhipeng; Zhang, Yiying; Xie, Zhongcong

2010-01-01

Background Recent studies have suggested that children having surgery under anesthesia could be at an increased risk for the development of learning disabilities, but whether anesthetics contribute to this learning disability is unclear. We therefore set out to assess effects of sevoflurane, the most commonly used inhalation anesthetic, on caspase activation, apoptosis, β-amyloid protein levels, and neuroinflammation in brain tissues of neonatal naïve and Alzheimer's disease (AD) transgenic mice. Methods Six-day-old naïve and AD transgenic [B6.Cg-Tg(amyloid precursor protein swe, PSEN1dE9)85Dbo/J] mice were treated with sevoflurane. The mice were euthanized at the end of the anesthesia and brain tissues were harvested, and were then subjected to Western blot, immunocytochemistry, ELISA and real-time polymerase chain reaction. Results Here we show for the first time that sevoflurane anesthesia induced caspase activation and apoptosis, altered amyloid precursor protein processing, and increased β-amyloid protein levels in the brain tissues of the neonatal mice. Furthermore, the sevoflurane anesthesia led to a greater degree of neurotoxicity in the brain tissues of the AD transgenic mice as compared to the naïve mice, and increased tumor necrosis factor-α levels only in the brain tissues of the AD transgenic mice. Finally, inositol 1,4,5-trisphosphate receptor antagonist 2-APB attenuated the sevoflurane-induced caspase-3 activation and β-amyloid protein accumulation in vivo. Conclusion These results suggest that sevoflurane may induce the neurotoxicity in neonatal mice. AD transgenic mice could be more venerable to such neurotoxicity. These findings should promote more studies to determine the potential neurotoxicity of anesthesia in animals and humans, especially in children. PMID:20460993

State dependence of noise correlations in macaque primary visual cortex

PubMed Central

Ecker, Alexander S.; Berens, Philipp; Cotton, R. James; Subramaniyan, Manivannan; Denfield, George H.; Cadwell, Cathryn R.; Smirnakis, Stelios M.; Bethge, Matthias; Tolias, Andreas S.

2014-01-01

Shared, trial-to-trial variability in neuronal populations has a strong impact on the accuracy of information processing in the brain. Estimates of the level of such noise correlations are diverse, ranging from 0.01 to 0.4, with little consensus on which factors account for these differences. Here we addressed one important factor that varied across studies, asking how anesthesia affects the population activity structure in macaque primary visual cortex. We found that under opioid anesthesia, activity was dominated by strong coordinated fluctuations on a timescale of 1–2 Hz, which were mostly absent in awake, fixating monkeys. Accounting for these global fluctuations markedly reduced correlations under anesthesia, matching those observed during wakefulness and reconciling earlier studies conducted under anesthesia and in awake animals. Our results show that internal signals, such as brain state transitions under anesthesia, can induce noise correlations, but can also be estimated and accounted for based on neuronal population activity. PMID:24698278

State dependence of noise correlations in macaque primary visual cortex.

PubMed

Ecker, Alexander S; Berens, Philipp; Cotton, R James; Subramaniyan, Manivannan; Denfield, George H; Cadwell, Cathryn R; Smirnakis, Stelios M; Bethge, Matthias; Tolias, Andreas S

2014-04-02

Shared, trial-to-trial variability in neuronal populations has a strong impact on the accuracy of information processing in the brain. Estimates of the level of such noise correlations are diverse, ranging from 0.01 to 0.4, with little consensus on which factors account for these differences. Here we addressed one important factor that varied across studies, asking how anesthesia affects the population activity structure in macaque primary visual cortex. We found that under opioid anesthesia, activity was dominated by strong coordinated fluctuations on a timescale of 1-2 Hz, which were mostly absent in awake, fixating monkeys. Accounting for these global fluctuations markedly reduced correlations under anesthesia, matching those observed during wakefulness and reconciling earlier studies conducted under anesthesia and in awake animals. Our results show that internal signals, such as brain state transitions under anesthesia, can induce noise correlations but can also be estimated and accounted for based on neuronal population activity. Copyright © 2014 Elsevier Inc. All rights reserved.

Robust Long-Range Coordination of Spontaneous Neural Activity in Waking, Sleep and Anesthesia.

PubMed

Liu, Xiao; Yanagawa, Toru; Leopold, David A; Fujii, Naotaka; Duyn, Jeff H

2015-09-01

Although the emerging field of functional connectomics relies increasingly on the analysis of spontaneous fMRI signal covariation to infer the spatial fingerprint of the brain's large-scale functional networks, the nature of the underlying neuro-electrical activity remains incompletely understood. In part, this lack in understanding owes to the invasiveness of electrophysiological acquisition, the difficulty in their simultaneous recording over large cortical areas, and the absence of fully established methods for unbiased extraction of network information from these data. Here, we demonstrate a novel, data-driven approach to analyze spontaneous signal variations in electrocorticographic (ECoG) recordings from nearly entire hemispheres of macaque monkeys. Based on both broadband analysis and analysis of specific frequency bands, the ECoG signals were found to co-vary in patterns that resembled the fMRI networks reported in previous studies. The extracted patterns were robust against changes in consciousness associated with sleep and anesthesia, despite profound changes in intrinsic characteristics of the raw signals, including their spectral signatures. These results suggest that the spatial organization of large-scale brain networks results from neural activity with a broadband spectral feature and is a core aspect of the brain's physiology that does not depend on the state of consciousness. Published by Oxford University Press 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Awake craniotomy anesthetic management using dexmedetomidine, propofol, and remifentanil

PubMed Central

Prontera, Andrea; Baroni, Stefano; Marudi, Andrea; Valzania, Franco; Feletti, Alberto; Benuzzi, Francesca; Bertellini, Elisabetta; Pavesi, Giacomo

2017-01-01

Introduction Awake craniotomy allows continuous monitoring of patients’ neurological functions during open surgery. Anesthesiologists have to sedate patients in a way so that they are compliant throughout the whole surgical procedure, nevertheless maintaining adequate analgesia and anxiolysis. Currently, the use of α2-receptor agonist dexmedetomidine as the primary hypnotic–sedative medication is increasing. Methods Nine patients undergoing awake craniotomy were treated with refined monitored anesthesia care (MAC) protocol consisting of a combination of local anesthesia without scalp block, low-dose infusion of dexmedetomidine, propofol, and remifentanil, without the need of airways management. Results The anesthetic protocol applied in our study has the advantage of decreasing the dose of each drug and thus reducing the occurrence of side effects. All patients had smooth and rapid awakenings. The brain remained relaxed during the entire procedure. Conclusion In our experience, this protocol is safe and effective during awake brain surgery. Nevertheless, prospective randomized trials are necessary to confirm the optimal anesthetic technique to be used. PMID:28424537

Awake craniotomy anesthetic management using dexmedetomidine, propofol, and remifentanil.

PubMed

Prontera, Andrea; Baroni, Stefano; Marudi, Andrea; Valzania, Franco; Feletti, Alberto; Benuzzi, Francesca; Bertellini, Elisabetta; Pavesi, Giacomo

2017-01-01

Awake craniotomy allows continuous monitoring of patients' neurological functions during open surgery. Anesthesiologists have to sedate patients in a way so that they are compliant throughout the whole surgical procedure, nevertheless maintaining adequate analgesia and anxiolysis. Currently, the use of α2-receptor agonist dexmedetomidine as the primary hypnotic-sedative medication is increasing. Nine patients undergoing awake craniotomy were treated with refined monitored anesthesia care (MAC) protocol consisting of a combination of local anesthesia without scalp block, low-dose infusion of dexmedetomidine, propofol, and remifentanil, without the need of airways management. The anesthetic protocol applied in our study has the advantage of decreasing the dose of each drug and thus reducing the occurrence of side effects. All patients had smooth and rapid awakenings. The brain remained relaxed during the entire procedure. In our experience, this protocol is safe and effective during awake brain surgery. Nevertheless, prospective randomized trials are necessary to confirm the optimal anesthetic technique to be used.

Estimating the Integrated Information Measure Phi from High-Density Electroencephalography during States of Consciousness in Humans

PubMed Central

Kim, Hyoungkyu; Hudetz, Anthony G.; Lee, Joseph; Mashour, George A.; Lee, UnCheol; Avidan, Michael S.

2018-01-01

The integrated information theory (IIT) proposes a quantitative measure, denoted as Φ, of the amount of integrated information in a physical system, which is postulated to have an identity relationship with consciousness. IIT predicts that the value of Φ estimated from brain activities represents the level of consciousness across phylogeny and functional states. Practical limitations, such as the explosive computational demands required to estimate Φ for real systems, have hindered its application to the brain and raised questions about the utility of IIT in general. To achieve practical relevance for studying the human brain, it will be beneficial to establish the reliable estimation of Φ from multichannel electroencephalogram (EEG) and define the relationship of Φ to EEG properties conventionally used to define states of consciousness. In this study, we introduce a practical method to estimate Φ from high-density (128-channel) EEG and determine the contribution of each channel to Φ. We examine the correlation of power, frequency, functional connectivity, and modularity of EEG with regional Φ in various states of consciousness as modulated by diverse anesthetics. We find that our approximation of Φ alone is insufficient to discriminate certain states of anesthesia. However, a multi-dimensional parameter space extended by four parameters related to Φ and EEG connectivity is able to differentiate all states of consciousness. The association of Φ with EEG connectivity during clinically defined anesthetic states represents a new practical approach to the application of IIT, which may be used to characterize various physiological (sleep), pharmacological (anesthesia), and pathological (coma) states of consciousness in the human brain. PMID:29503611

Estimating the Integrated Information Measure Phi from High-Density Electroencephalography during States of Consciousness in Humans.

PubMed

Kim, Hyoungkyu; Hudetz, Anthony G; Lee, Joseph; Mashour, George A; Lee, UnCheol

2018-01-01

The integrated information theory (IIT) proposes a quantitative measure, denoted as Φ, of the amount of integrated information in a physical system, which is postulated to have an identity relationship with consciousness. IIT predicts that the value of Φ estimated from brain activities represents the level of consciousness across phylogeny and functional states. Practical limitations, such as the explosive computational demands required to estimate Φ for real systems, have hindered its application to the brain and raised questions about the utility of IIT in general. To achieve practical relevance for studying the human brain, it will be beneficial to establish the reliable estimation of Φ from multichannel electroencephalogram (EEG) and define the relationship of Φ to EEG properties conventionally used to define states of consciousness. In this study, we introduce a practical method to estimate Φ from high-density (128-channel) EEG and determine the contribution of each channel to Φ. We examine the correlation of power, frequency, functional connectivity, and modularity of EEG with regional Φ in various states of consciousness as modulated by diverse anesthetics. We find that our approximation of Φ alone is insufficient to discriminate certain states of anesthesia. However, a multi-dimensional parameter space extended by four parameters related to Φ and EEG connectivity is able to differentiate all states of consciousness. The association of Φ with EEG connectivity during clinically defined anesthetic states represents a new practical approach to the application of IIT, which may be used to characterize various physiological (sleep), pharmacological (anesthesia), and pathological (coma) states of consciousness in the human brain.

Tracking brain states under general anesthesia by using global coherence analysis

PubMed Central

Cimenser, Aylin; Purdon, Patrick L.; Pierce, Eric T.; Walsh, John L.; Salazar-Gomez, Andres F.; Harrell, Priscilla G.; Tavares-Stoeckel, Casie; Habeeb, Kathleen; Brown, Emery N.

2011-01-01

Time and frequency domain analyses of scalp EEG recordings are widely used to track changes in brain states under general anesthesia. Although these analyses have suggested that different spatial patterns are associated with changes in the state of general anesthesia, the extent to which these patterns are spatially coordinated has not been systematically characterized. Global coherence, the ratio of the largest eigenvalue to the sum of the eigenvalues of the cross-spectral matrix at a given frequency and time, has been used to analyze the spatiotemporal dynamics of multivariate time-series. Using 64-lead EEG recorded from human subjects receiving computer-controlled infusions of the anesthetic propofol, we used surface Laplacian referencing combined with spectral and global coherence analyses to track the spatiotemporal dynamics of the brain's anesthetic state. During unconsciousness the spectrograms in the frontal leads showed increasing α (8–12 Hz) and δ power (0–4 Hz) and in the occipital leads δ power greater than α power. The global coherence detected strong coordinated α activity in the occipital leads in the awake state that shifted to the frontal leads during unconsciousness. It revealed a lack of coordinated δ activity during both the awake and unconscious states. Although strong frontal power during general anesthesia-induced unconsciousness—termed anteriorization—is well known, its possible association with strong α range global coherence suggests highly coordinated spatial activity. Our findings suggest that combined spectral and global coherence analyses may offer a new approach to tracking brain states under general anesthesia. PMID:21555565

Loss of consciousness is related to hyper-correlated gamma-band activity in anesthetized macaques and sleeping humans.

PubMed

Bola, Michał; Barrett, Adam B; Pigorini, Andrea; Nobili, Lino; Seth, Anil K; Marchewka, Artur

2018-02-15

Loss of consciousness can result from a wide range of causes, including natural sleep and pharmacologically induced anesthesia. Important insights might thus come from identifying neuronal mechanisms of loss and re-emergence of consciousness independent of a specific manipulation. Therefore, to seek neuronal signatures of loss of consciousness common to sleep and anesthesia we analyzed spontaneous electrophysiological activity recorded in two experiments. First, electrocorticography (ECoG) acquired from 4 macaque monkeys anesthetized with different anesthetic agents (ketamine, medetomidine, propofol) and, second, stereo-electroencephalography (sEEG) from 10 epilepsy patients in different wake-sleep stages (wakefulness, NREM, REM). Specifically, we investigated co-activation patterns among brain areas, defined as correlations between local amplitudes of gamma-band activity. We found that resting wakefulness was associated with intermediate levels of gamma-band coupling, indicating neither complete dependence, nor full independence among brain regions. In contrast, loss of consciousness during NREM sleep and propofol anesthesia was associated with excessively correlated brain activity, as indicated by a robust increase of number and strength of positive correlations. However, such excessively correlated brain signals were not observed during REM sleep, and were present only to a limited extent during ketamine anesthesia. This might be related to the fact that, despite suppression of behavioral responsiveness, REM sleep and ketamine anesthesia often involve presence of dream-like conscious experiences. We conclude that hyper-correlated gamma-band activity might be a signature of loss of consciousness common across various manipulations and independent of behavioral responsiveness. Copyright © 2017 Elsevier Inc. All rights reserved.

Brain-Derived Neurotrophic Factor (BDNF) and Traumatic Brain Injury (Head and Spinal)

DTIC Science & Technology

1999-01-01

surface area. J Microscopy 150: 117-136. Osterman-Latif C, Mader M, Felgenhauer K (1993) An efficient sandwich-ELISA for the determination of choline ...anesthesia and surgery but were not injured (sham injury). After the appropriate survival times, the rats were deeply anesthetized with an overdose of...post-injury (Hicks et al., 1997b, 1998). Tissue Processing Following deep anesthesia with an overdose of sodium pentobarbital, the animals ".vere

Clinical Electroencephalography for Anesthesiologists Part I: Background and Basic Signatures

PubMed Central

Purdon, Patrick L.; Sampson, Aaron; Pavone, Kara J.; Brown, Emery N.

2015-01-01

The widely used electroencephalogram-based indices for depth-of-anesthesia monitoring assume that the same index value defines the same level of unconsciousness for all anesthetics. In contrast, we show that different anesthetics act at different molecular targets and neural circuits to produce distinct brain states that are readily visible in the electroencephalogram. We present a two-part review to educate anesthesiologists on use of the unprocessed electroencephalogram and its spectrogram to track the brain states of patients receiving anesthesia care. Here in Part I, we review the biophysics of the electroencephalogram, and the neurophysiology of the electroencephalogram signatures of three intravenous anesthetics: propofol, dexmedetomidine and ketamine; and four inhaled anesthetics: sevoflurane, isoflurane, desflurane and nitrous oxide. Later in Part II, we discuss patient management using these electroencephalogram signatures. Use of these electroencephalogram signatures suggests a neurophysiologically-based paradigm for brain-state monitoring of patients receiving anesthesia care. PMID:26275092

[AWAKE CRANIOTOMY: IN SEARCH FOR OPTIMAL SEDATION].

PubMed

Kulikova, A S; Sel'kov, D A; Kobyakov, G L; Shmigel'skiy, A V; Lubnin, A Yu

2015-01-01

Awake craniotomy is a "gold standard"for intraoperative brain language mapping. One of the main anesthetic challenge of awake craniotomy is providing of optimal sedation for initial stages of intervention. The goal of this study was comparison of different technics of anesthesia for awake craniotomy. Materials and methods: 162 operations were divided in 4 groups: 76 cases with propofol sedation (2-4mg/kg/h) without airway protection; 11 cases with propofol sedation (4-5 mg/kg/h) with MV via LMA; 36 cases of xenon anesthesia; and 39 cases with dexmedetomidine sedation without airway protection. Results and discussion: brain language mapping was successful in 90% of cases. There was no difference between groups in successfulness of brain mapping. However in the first group respiratory complications were more frequent. Three other technics were more safer Xenon anesthesia was associated with ultrafast awakening for mapping (5±1 min). Dexmedetomidine sedation provided high hemodynamic and respiratory stability during the procedure.

The common inhalation anesthetic isoflurane induces caspase activation and increases amyloid beta-protein level in vivo.

PubMed

Xie, Zhongcong; Culley, Deborah J; Dong, Yuanlin; Zhang, Guohua; Zhang, Bin; Moir, Robert D; Frosch, Matthew P; Crosby, Gregory; Tanzi, Rudolph E

2008-12-01

An estimated 200 million patients worldwide have surgery each year. Anesthesia and surgery have been reported to facilitate emergence of Alzheimer's disease. The commonly used inhalation anesthetic isoflurane has previously been reported to induce apoptosis, and to increase levels and aggregation of Alzheimer's disease-associated amyloid beta-protein (Abeta) in cultured cells. However, the in vivo relevance has not been addressed. We therefore set out to determine effects of isoflurane on caspase activation and levels of beta-site amyloid precursor protein-cleaving enzyme (BACE) and Abeta in naive mice, using Western blot, immunohistochemistry, and reverse transcriptase polymerase chain reaction. Here we show for the first time that a clinically relevant isoflurane anesthesia (1.4% isoflurane for 2 hours) leads to caspase activation and modest increases in levels of BACE 6 hours after anesthesia in mouse brain. Isoflurane anesthesia induces caspase activation, and increases levels of BACE and Abeta up to 24 hours after anesthesia. Isoflurane may increase BACE levels by reducing BACE degradation. Moreover, the Abeta aggregation inhibitor, clioquinol, was able to attenuate isoflurane-induced caspase-3 activation in vivo. Given that transient insults to brain may lead to long-term brain damage, these findings suggest that isoflurane may promote Alzheimer's disease neuropathogenesis and, as such, have implications for use of isoflurane in humans, pending human study confirmation.

Incidence, Risk Factors and Consequences of Emergence Agitation in Adult Patients after Elective Craniotomy for Brain Tumor: A Prospective Cohort Study

PubMed Central

Chen, Lu; Xu, Ming; Li, Gui-Yun; Cai, Wei-Xin; Zhou, Jian-Xin

2014-01-01

Emergence agitation is a frequent complication that can have serious consequences during recovery from general anesthesia. However, agitation has been poorly investigated in patients after craniotomy. In this prospective cohort study, adult patients were enrolled after elective craniotomy for brain tumor. The sedation-agitation scale was evaluated during the first 12 hours after surgery. Agitation developed in 35 of 123 patients (29%). Of the agitated patients, 28 (80%) were graded as very and dangerously agitated. By multivariate stepwise logistic regression analysis, independent predictors for agitation included male sex, history of long-term use of anti-depressant drugs or benzodiazepines, frontal approach of the operation, method and duration of anesthesia and presence of endotracheal intubation. Total intravenous anesthesia and balanced anesthesia with short duration were protective factors. Emergence agitation was associated with self-extubation (8.6% vs 0%, P = 0.005). Sedatives were administered more in agitated patients than non-agitated patients (85.7% vs 6.8%, P<0.001). In conclusion, emergence agitation was a frequent complication in patients after elective craniotomy for brain tumors. The clarification of risk factors could help to identify the high-risk patients, and then to facilitate the prevention and treatment of agitation. For patients undergoing craniotomy, greater attention should be paid to those receiving a frontal approach for craniotomy and those anesthetized under balanced anesthesia with long duration. More researches are warranted to elucidate whether total intravenous anesthesia could reduce the incidence of agitation after craniotomy. Trial Registration ClinicalTrials.gov NCT00590499. PMID:25493435

Reduction in radiation-induced brain injury by use of pentobarbital or lidocaine protection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oldfield, E.H.; Friedman, R.; Kinsella, T.

1990-05-01

To determine if barbiturates would protect brain at high doses of radiation, survival rates in rats that received whole-brain x-irradiation during pentobarbital- or lidocaine-induced anesthesia were compared with those of control animals that received no medication and of animals anesthetized with ketamine. The animals were shielded so that respiratory and digestive tissues would not be damaged by the radiation. Survival rates in rats that received whole-brain irradiation as a single 7500-rad dose under pentobarbital- or lidocaine-induced anesthesia was increased from between from 0% and 20% to between 45% and 69% over the 40 days of observation compared with the othermore » two groups (p less than 0.007). Ketamine anesthesia provided no protection. There were no notable differential effects upon non-neural tissues, suggesting that pentobarbital afforded protection through modulation of ambient neural activity during radiation exposure. Neural suppression during high-dose cranial irradiation protects brain from acute and early delayed radiation injury. Further development and application of this knowledge may reduce the incidence of radiation toxicity of the central nervous system (CNS) and may permit the safe use of otherwise unsafe doses of radiation in patients with CNS neoplasms.« less

[Characteristics of perioperative period in Xenon-based combined general anaesthesia in neurosurgery].

PubMed

Viatkin, A A; Petrosian, L G; Mizikov, V M; Vasil'ev, S A

2013-01-01

Neuroprotection could be the aim to use Xenon for general anesthesia. However the experience of Xenon anesthesia in neurosurgery is quite limited. The appraisal of Xenon based anesthesia was accomplished in 12 patients during various brain surgery. Xe in concentration 65% was used to maintenance of anesthesia, other medication was avoided. As a resuIt there were 8 cases of arterial hypertension and 2 cases of superficial hypnotic state. Excitation (n = 3), hyperdynamic reaction (n = 8), PONV (n = 8) were detected in early postoperative period. An analysis of this study suggests a conclusion that studied method of Xenon-based anesthesia is inexpedient for neurosurgery.

The Fas Ligand/Fas Death Receptor Pathways Contribute to Propofol-Induced Apoptosis and Neuroinflammation in the Brain of Neonatal Rats.

PubMed

Milanovic, Desanka; Pesic, Vesna; Loncarevic-Vasiljkovic, Natasa; Pavkovic, Zeljko; Popic, Jelena; Kanazir, Selma; Jevtovic-Todorovic, Vesna; Ruzdijic, Sabera

2016-10-01

A number of experimental studies have reported that exposure to common, clinically used anesthetics induce extensive neuroapoptosis and cognitive impairment when applied to young rodents, up to 2 weeks old, in phase of rapid synaptogenesis. Propofol is the most used general anesthetic in clinical practice whose mechanisms of neurotoxicity on the developing brain remains to be examined in depth. This study investigated effects of different exposures to propofol anesthesia on Fas receptor and Fas ligand expressions, which mediate proapoptotic and proinflammation signaling in the brain. Propofol (20 mg/kg) was administered to 7-day-old rats in multiple doses sufficient to maintain 2-, 4- and 6-h duration of anesthesia. Animals were sacrificed at 0, 4, 16 and 24 h after termination of anesthesia. It was found that propofol anesthesia induced Fas/FasL and downstream caspase-8 expression more prominently in the thalamus than in the cortex. Opposite, Bcl-2 and caspase-9, markers of intrinsic pathway activation, were shown to be more influenced by propofol treatment in the cortex. Further, we have established upregulation of caspase-1 and IL-1β cytokine transcription as well as subsequent activation of microglia that is potentially associated with brain inflammation. Behavioral analyses revealed that P35 and P60 animals, neonatally exposed to propofol, had significantly higher motor activity during three consecutive days of testing in the open field, though formation of the intersession habituation was not prevented. This data, together with our previous results, contributes to elucidation of complex mechanisms of propofol toxicity in developing brain.

Glymphatic clearance controls state-dependent changes in brain lactate concentration.

PubMed

Lundgaard, Iben; Lu, Minh Lon; Yang, Ezra; Peng, Weiguo; Mestre, Humberto; Hitomi, Emi; Deane, Rashid; Nedergaard, Maiken

2017-06-01

Brain lactate concentration is higher during wakefulness than in sleep. However, it is unknown why arousal is linked to an increase in brain lactate and why lactate declines within minutes of sleep. Here, we show that the glymphatic system is responsible for state-dependent changes in brain lactate concentration. Suppression of glymphatic function via acetazolamide treatment, cisterna magna puncture, aquaporin 4 deletion, or changes in body position reduced the decline in brain lactate normally observed when awake mice transition into sleep or anesthesia. Concurrently, the same manipulations diminished accumulation of lactate in cervical, but not in inguinal lymph nodes when mice were anesthetized. Thus, our study suggests that brain lactate is an excellent biomarker of the sleep-wake cycle and increases further during sleep deprivation, because brain lactate is inversely correlated with glymphatic-lymphatic clearance. This analysis provides fundamental new insight into brain energy metabolism by demonstrating that glucose that is not fully oxidized can be exported as lactate via glymphatic-lymphatic fluid transport.

Glymphatic clearance controls state-dependent changes in brain lactate concentration

PubMed Central

Lu, Minh Lon; Yang, Ezra; Peng, Weiguo; Mestre, Humberto; Hitomi, Emi; Deane, Rashid; Nedergaard, Maiken

2016-01-01

Brain lactate concentration is higher during wakefulness than in sleep. However, it is unknown why arousal is linked to an increase in brain lactate and why lactate declines within minutes of sleep. Here, we show that the glymphatic system is responsible for state-dependent changes in brain lactate concentration. Suppression of glymphatic function via acetazolamide treatment, cisterna magna puncture, aquaporin 4 deletion, or changes in body position reduced the decline in brain lactate normally observed when awake mice transition into sleep or anesthesia. Concurrently, the same manipulations diminished accumulation of lactate in cervical, but not in inguinal lymph nodes when mice were anesthetized. Thus, our study suggests that brain lactate is an excellent biomarker of the sleep–wake cycle and increases further during sleep deprivation, because brain lactate is inversely correlated with glymphatic-lymphatic clearance. This analysis provides fundamental new insight into brain energy metabolism by demonstrating that glucose that is not fully oxidized can be exported as lactate via glymphatic-lymphatic fluid transport. PMID:27481936

Correlation of bispectral index (BIS) monitoring and end-tidal sevoflurane concentration in a patient with lobar holoprosencephaly.

PubMed

Galante, Dario; Fortarezza, Donatella; Caggiano, Maria; de Francisci, Giovanni; Pedrotti, Dino; Caruselli, Marco

2015-01-01

The bispectral index (BIS) is a parameter derived by electroencephalography (EEG) which provides a direct measurement of the effects of sedatives and anesthetics on the brain and offers guidance on the adequacy of anesthesia. The literature lacks studies on BIS monitoring in pediatric patients with congenital brain disease undergoing general anesthesia. A 13-year-old child weighing 32kg, suffering from lobar holoprosencephaly, underwent surgery in which the bispectral index (BIS) monitoring the depth of anesthesia showed an abnormal response. Detailed analysis of the trends of BIS values in the different observation times demonstrated sudden falls and repetitive values of BIS likely related to repetitive epileptiform electrical activity caused by sevoflurane. The BIS is a very useful monitoring tool for assessing the degree of depth of anesthesia and to analyze the electroencephalographic variations of anesthetics. Particular attention should be given to patients with congenital disorders of the central nervous system in which the BIS may give abnormal responses that do not reflect an accurate assessment of the depth of anesthesia. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

[Correlation of bispectral index (BIS) monitoring and end-tidal sevoflurane concentration in a patient with lobar holoprosencephaly].

PubMed

Galante, Dario; Fortarezza, Donatella; Caggiano, Maria; de Francisci, Giovanni; Pedrotti, Dino; Caruselli, Marco

2015-01-01

The bispectral index (BIS) is a parameter derived by electroencephalography (EEG) which provides a direct measurement of the effects of sedatives and anesthetics on the brain and offers guidance on the adequacy of anesthesia. The literature lacks studies on BIS monitoring in pediatric patients with congenital brain disease undergoing general anesthesia. A 13-year-old child weighing 32kg, suffering from lobar holoprosencephaly, underwent surgery in which the bispectral index (BIS) monitoring the depth of anesthesia showed an abnormal response. Detailed analysis of the trends of BIS values in the different observation times demonstrated sudden falls and repetitive values of BIS likely related to repetitive epileptiform electrical activity caused by sevoflurane. The BIS is a very useful monitoring tool for assessing the degree of depth of anesthesia and to analyze the electroencephalographic variations of anesthetics. Particular attention should be given to patients with congenital disorders of the central nervous system in which the BIS may give abnormal responses that do not reflect an accurate assessment of the depth of anesthesia. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Tracking the coupling of two electroencephalogram series in the isoflurane and remifentanil anesthesia.

PubMed

Liang, Zhenhu; Liang, Shujuan; Wang, Yinghua; Ouyang, Gaoxiang; Li, Xiaoli

2015-02-01

Coupling in multiple electroencephalogram (EEG) signals provides a perspective tool to understand the mechanism of brain communication. In this study, we propose a method based on permutation cross-mutual information (PCMI) to investigate whether or not the coupling between EEG series can be used to quantify the effect of specific anesthetic drugs (isoflurane and remifentanil) on brain activities. A Rössler-Lorenz system and surrogate analysis was first employed to compare histogram-based mutual information (HMI) and PCMI for estimating the coupling of two nonlinear systems. Then, the HMI and the PCMI indices of EEG recordings from two sides of the forehead of 12 patients undergoing combined remifentanil and isoflurane anesthesia were demonstrated for tracking the effect of drug on the coupling of brain activities. Performance of all indices was assessed by the correlation coefficients (Rij) and relative coefficient of variation (CV). The PCMI can track the coupling strength of two nonlinear systems, and it is sensitive to the phase change of the coupling systems. Compared to the HMI, the PCMI has a better correlation with the coupling strength in nonlinear systems. The PCMI could track the effect of anesthesia and distinguish the consciousness state from the unconsciousness state. Moreover, at the embedding dimension m=4 and lag τ=1, the PCMI had a better performance than HMI in tracking the effect of anesthesia drugs on brain activities. As a measure of coupling, the PCMI was able to reflect the state of consciousness from two EEG recordings. The PCMI is a promising new coupling measure for estimating the effect of isoflurane and remifentanil anesthetic drugs on the brain activity. Copyright © 2014 International Federation of Clinical Neurophysiology. All rights reserved.

Spectral entropy in monitoring anesthetic depth.

PubMed

Escontrela Rodríguez, B; Gago Martínez, A; Merino Julián, I; Martínez Ruiz, A

2016-10-01

Monitoring the brain response to hypnotics in general anesthesia, with the nociceptive and hemodynamic stimulus interaction, has been a subject of intense investigation for many years. Nowadays, monitors of depth of anesthesia are based in processed electroencephalogram by different algorithms, some of them unknown, to obtain a simplified numeric parameter approximate to brain activity state in each moment. In this review we evaluate if spectral entropy suitably reflects the brain electric behavior in response to hypnotics and the different intensity nociceptive stimulus effect during a surgical procedure. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Multiscale rescaled range analysis of EEG recordings in sevoflurane anesthesia.

PubMed

Liang, Zhenhu; Li, Duan; Ouyang, Gaoxiang; Wang, Yinghua; Voss, Logan J; Sleigh, Jamie W; Li, Xiaoli

2012-04-01

The Hurst exponent (HE) is a nonlinear method measuring the smoothness of a fractal time series. In this study we applied the HE index, extracted from electroencephalographic (EEG) recordings, as a measure of anesthetic drug effects on brain activity. In 19 adult patients undergoing sevoflurane general anesthesia, we calculated the HE of the raw EEG; comparing the maximal overlap discrete wavelet transform (MODWT) with the traditional rescaled range (R/S) analysis techniques, and with a commercial index of depth of anesthesia - the response entropy (RE). We analyzed each wavelet-decomposed sub-band as well as the combined low frequency bands (HEOLFBs). The methods were compared in regard to pharmacokinetic/pharmacodynamic (PK/PD) modeling, and prediction probability. All the low frequency band HE indices decreased when anesthesia deepened. However the HEOLFB was the best index because: it was less sensitive to artifacts, most closely tracked the exact point of loss of consciousness, showed a better prediction probability in separating the awake and unconscious states, and tracked sevoflurane concentration better - as estimated by the PK/PD models. The HE is a useful measure for estimating the depth of anesthesia. It was noted that HEOLFB showed the best performance for tracking drug effect. The HEOLFB could be used as an index for accurately estimating the effect of anesthesia on brain activity. Copyright © 2011 International Federation of Clinical Neurophysiology. All rights reserved.

The human brain pacemaker: Synchronized infra-slow neurovascular coupling in patients undergoing non-pulsatile cardiopulmonary bypass.

PubMed

Zanatta, Paolo; Toffolo, Gianna Maria; Sartori, Elisa; Bet, Anna; Baldanzi, Fabrizio; Agarwal, Nivedita; Golanov, Eugene

2013-05-15

In non-pulsatile cardiopulmonary bypass surgery, middle cerebral artery blood flow velocity (BFV) is characterized by infra-slow oscillations of approximately 0.06Hz, which are paralleled by changes in total EEG power variability (EEG-PV), measured in 2s intervals. Since the origin of these BFV oscillations is not known, we explored their possible causative relationships with oscillations in EEG-PV at around 0.06Hz. We monitored 28 patients undergoing non-pulsatile cardiopulmonary bypass using transcranial Doppler sonography and scalp electroencephalography at two levels of anesthesia, deep (prevalence of burst suppression rhythm) and moderate (prevalence of theta rhythm). Under deep anesthesia, the EEG bursts suppression pattern was highly correlative with BFV oscillations. Hence, a detailed quantitative picture of the coupling between electrical brain activity and BFV was derived, both in deep and moderate anesthesia, via linear and non linear processing of EEG-PV and BFV signals, resorting to widely used measures of signal coupling such as frequency of oscillations, coherence, Granger causality and cross-approximate entropy. Results strongly suggest the existence of coupling between EEG-PV and BFV. In moderate anesthesia EEG-PV mean dominant frequency is similar to frequency of BFV oscillations (0.065±0.010Hz vs 0.045±0.019Hz); coherence between the two signals was significant in about 55% of subjects, and the Granger causality suggested an EEG-PV→BFV causal effect direction. The strength of the coupling increased with deepening anesthesia, as EEG-PV oscillations mean dominant frequency virtually coincided with the BFV peak frequency (0.062±0.017Hz vs 0.060±0.024Hz), and coherence became significant in a larger number (65%) of subjects. Cross-approximate entropy decreased significantly from moderate to deep anesthesia, indicating a higher level of synchrony between the two signals. Presence of a subcortical brain pacemaker that drives vascular infra-slow oscillations in the brain is proposed. These findings allow to suggest an original hypothesis explaining the mechanism underlying infra-slow neurovascular coupling. Copyright © 2013 Elsevier Inc. All rights reserved.

Controlled Cortical Impact in Swine: Pathophysiology and Biomechanics

DTIC Science & Technology

2005-03-28

et al 3/28/05 free access to food and water until 12 h before anesthesia was induced. After intubation, anesthesia was maintained with a fentanyl ...injury in 10 of these 13 animals. Histological Studies After completion of monitoring, the swine received an overdose of pentobarbital. The brain was

Exposure to Surgery and Anesthesia After Concussion Due to Mild Traumatic Brain Injury.

PubMed

Abcejo, Arnoley S; Savica, Rodolfo; Lanier, William L; Pasternak, Jeffrey J

2017-07-01

To describe the epidemiology of surgical and anesthetic procedures in patients recently diagnosed as having a concussion due to mild traumatic brain injury. Study patients presented to a tertiary care center after a concussion due to mild traumatic brain injury from July 1, 2005, through June 30, 2015, and underwent a surgical procedure and anesthesia support under the direct or indirect care of a physician anesthesiologist. During the study period, 1038 patients met all the study inclusion criteria and subsequently received 1820 anesthetics. In this population of anesthetized patients, rates of diagnosed concussions due to sports injuries, falls, and assaults, but not motor vehicle accidents, increased during 2010-2011. Concussions were diagnosed in 965 patients (93%) within 1 week after injury. In the 552 patients who had surgery within 1 week after concussive injury, 29 (5%) had anesthesia and surgical procedures unrelated to their concussion-producing traumatic injury. The highest use of surgery occurred early after injury and most frequently required general anesthesia. Orthopedic and general surgical procedures accounted for 57% of procedures. Nine patients received 29 anesthetics before a concussion diagnosis, and all of these patients had been involved in motor vehicle accidents and received at least 1 anesthetic within 1 week of injury. Surgical and anesthesia use are common in patients after concussion. Clinicians should have increased awareness for concussion in patients who sustain a trauma and may need to take measures to avoid potentially injury-augmenting cerebral physiology in these patients. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Disruption of frontal-parietal connectivity during conscious sedation by propofol administration.

PubMed

Kim, Pil-Jong; Kim, Hong-Gee; Noh, Gyu-Jeong; Koo, Yong-Seo; Shin, Teo Jeon

2017-09-27

The sedative state is a transitional state from wakefulness to general anesthesia. However, little is understood regarding the mechanism of conscious sedation, different from general anesthesia while maintaining wakefulness. In this study, we aimed to investigate changes in functional connectivity of the parietal-frontal network, implicated in wakefulness during conscious sedation induced by propofol infusion. The electroencephalography was obtained at the frontal and parietal areas of adult volunteers who maintain wakefulness during low-dose propofol infusion (1.5 mg/kg/h) over 1 h. Spectral Granger causality (GC) (δ, θ, α, β, and γ frequency bands) and time-domain GC were calculated during each stage of awake (before propofol administration), sedation, and recovery (after discontinuation of propofol). We also calculated the phase-locking index and compared it with GC during each stage. A decrease in GC from the frontal to parietal areas was observed particularly in the low-frequency bands during propofol administration. Contrary to the GC changes in the frontoparietal direction, GC from the parietal to frontal areas was increased in the high-frequency bands during propofol administration and significantly decreased after discontinuation of propofol. In summary, we showed that frontal-parietal neural networks were significantly changed differently by the frequency of the brain rhythm and the directions of connections during sedation by propofol administration. Our result suggests that the alteration of brain interaction may induce sedative state lying between awake and general anesthesia.

Intranasal Insulin Prevents Anesthesia-Induced Cognitive Impairment and Chronic Neurobehavioral Changes.

PubMed

Chen, Yanxing; Dai, Chun-Ling; Wu, Zhe; Iqbal, Khalid; Liu, Fei; Zhang, Baorong; Gong, Cheng-Xin

2017-01-01

General anesthesia increases the risk for cognitive impairment post operation, especially in the elderly and vulnerable individuals. Recent animal studies on the impact of anesthesia on postoperative cognitive impairment have provided some valuable insights, but much remains to be understood. Here, by using mice of various ages and conditions, we found that anesthesia with propofol and sevoflurane caused significant deficits in spatial learning and memory, as tested using Morris Water Maze (MWM) 2-6 days after anesthesia exposure, in aged (17-18 months old) wild-type (WT) mice and in adult (7-8 months old) 3xTg-AD mice (a triple transgenic mouse model of Alzheimer's disease (AD)), but not in adult WT mice. Anesthesia resulted in long-term neurobehavioral changes in the fear conditioning task carried out 65 days after exposure to anesthesia in 3xTg-AD mice. Importantly, daily intranasal administration of insulin (1.75 U/mouse/day) for only 3 days prior to anesthesia completely prevented the anesthesia-induced deficits in spatial learning and memory and the long-term neurobehavioral changes tested 65 days after exposure to anesthesia in 3xTg-AD mice. These results indicate that aging and AD-like brain pathology increase the vulnerability to cognitive impairment after anesthesia and that intranasal treatment with insulin can prevent anesthesia-induced cognitive impairment.

The sensory thalamus and cerebral motor cortex are affected concurrently during induction of anesthesia with propofol: a case series with intracranial electroencephalogram recordings.

PubMed

Verdonck, Olivier; Reed, Sean J; Hall, Jeffery; Gotman, Jean; Plourde, Gilles

2014-03-01

Brain imaging studies suggest that loss of consciousness induced by general anesthetics is associated with impairment of thalamic function. There is, however, limited information on the time course of these changes. We recently obtained intracranial electroencephalogram (EEG) recordings from the ventroposterolateral (VPL) nucleus of the thalamus and from the motor cortex during induction of anesthesia in three patients to study the time course of the alterations of cortical and thalamic function. The patients were American Society of Anesthesiologists physical status I-II males aged 33-57 yr with intractable central pain caused by brachial plexus injury (patient 1 and 2) or insular infarct (patient 3). Anesthesia was induced with propofol (2.5-3.1 mg·kg(-1) over 30-45 sec) followed, after loss of consciousness, by rocuronium for tracheal intubation. The data retained for analysis are from one minute before the start of propofol to 110 sec later during ventilation of the patients' lungs before tracheal intubation. Spectral analysis was used to measure absolute EEG power. Propofol caused significant increases of cortical and thalamic power in the delta to beta frequency bands (1-30 Hz). These increases of cortical and thalamic power occurred either concomitantly or within seconds of each other. Propofol also caused a decrease in cortical and thalamic high-gamma (62-200 Hz) power that also followed a similar time course. We conclude that induction of anesthesia with propofol in these patients was associated with concurrent alterations of cortical and sensory thalamic activity.

An update on anesthetics and impact on the brain.

PubMed

Fodale, Vincenzo; Tripodi, Vincenzo F; Penna, Olivia; Famà, Fausto; Squadrito, Francesco; Mondello, Epifanio; David, Antonio

2017-09-01

While anesthetics are indispensable clinical tools and generally considered safe and effective, a growing concern over the potential neurotoxicity of anesthesia or specific anesthetic agents has called into question the safety of general anesthetics, especially when administered at extremes of age. Areas covered: This article reviews and updates research findings on the safety of anesthesia and anesthetics in terms of long-term neurotoxicity, with particular focus on postoperative cognitive dysfunctions, Alzheimer's disease and dementias, developing brain, post-operative depression and autism spectrum disorder. Expert opinion: Exposure to general anesthetics is potentially harmful to the human brain, and the consequent long-term cognitive deficits should be classified as an iatrogenic pathology, and considered a public health problem. The fact that in laboratory and clinical research only certain anesthetic agents and techniques, but not others, appear to be involved, raises the problem on what is the safest and the least safe anesthetic to maximize anesthesia efficiency, avoid occurrence of adverse events, and ensure patient safety. New trends in research are moving toward the theory that neuroinflammation could be the hallmark of, or could have a pivotal role in, several neurological disorders.

A Pharmacokinetics-Neural Mass Model (PK-NMM) for the Simulation of EEG Activity during Propofol Anesthesia

PubMed Central

Liang, Zhenhu; Duan, Xuejing; Su, Cui; Voss, Logan; Sleigh, Jamie; Li, Xiaoli

2015-01-01

Modeling the effects of anesthetic drugs on brain activity is very helpful in understanding anesthesia mechanisms. The aim of this study was to set up a combined model to relate actual drug levels to EEG dynamics and behavioral states during propofol-induced anesthesia. We proposed a new combined theoretical model based on a pharmacokinetics (PK) model and a neural mass model (NMM), which we termed PK-NMM—with the aim of simulating electroencephalogram (EEG) activity during propofol-induced general anesthesia. The PK model was used to derive propofol effect-site drug concentrations (C eff) based on the actual drug infusion regimen. The NMM model took C eff as the control parameter to produce simulated EEG-like (sEEG) data. For comparison, we used real prefrontal EEG (rEEG) data of nine volunteers undergoing propofol anesthesia from a previous experiment. To see how well the sEEG could describe the dynamic changes of neural activity during anesthesia, the rEEG data and the sEEG data were compared with respect to: power-frequency plots; nonlinear exponent (permutation entropy (PE)); and bispectral SynchFastSlow (SFS) parameters. We found that the PK-NMM model was able to reproduce anesthesia EEG-like signals based on the estimated drug concentration and patients’ condition. The frequency spectrum indicated that the frequency power peak of the sEEG moved towards the low frequency band as anesthesia deepened. Different anesthetic states could be differentiated by the PE index. The correlation coefficient of PE was 0.80±0.13 (mean±standard deviation) between rEEG and sEEG for all subjects. Additionally, SFS could track the depth of anesthesia and the SFS of rEEG and sEEG were highly correlated with a correlation coefficient of 0.77±0.13. The PK-NMM model could simulate EEG activity and might be a useful tool for understanding the action of propofol on brain activity. PMID:26720495

Oxidative and biochemical responses in Brycon amazonicus anesthetized and sedated with Myrcia sylvatica (G. Mey.) DC. and Curcuma longa L. essential oils.

PubMed

Saccol, Etiane M H; Londero, Érika P; Bressan, Caroline A; Salbego, Joseânia; Gressler, Luciane T; Silva, Lenise V F; Mourão, Rosa H V; Oliveira, Ricardo B; Llesuy, Susana F; Baldisserotto, Bernardo; Pavanato, Maria A

2017-05-01

To investigate the effects of rapid anesthesia and long-term sedation with the essential oils (EOs) of Myrcia sylvatica (EOMS) and Curcuma longa (EOCL) on biochemical and oxidative parameters in matrinxã. Prospective, randomized, laboratory experiment. A total of 72 matrinxã (Brycon amazonicus) adults weighing 404.8 ± 27.9 g were divided into eight groups of nine fish. Biochemical and oxidative effects were investigated in plasma and tissues of matrinxã subjected to rapid anesthesia (5 minutes) or long-term sedation (360 minutes, simulating the practice of transport) with EOMS (200 μL L -1 and 10 μL L -1 , respectively) and EOCL (500 μL L -1 and 40 μL L -1 , respectively). Transport simulation without sedation or anesthesia increased lipid peroxidation levels in the gills and kidney of fish in the control group. Anesthesia and sedation with EOs decreased cortisol concentrations and increased lactate concentrations compared with controls. Lipid peroxidation was lower in the brain, gills, liver and kidney of sedated and anesthetized fish, than in the control group. Anesthesia with EOs increased the activity of superoxide dismutase and glutathione-S-transferase in the brain, and catalase in the liver and gills, compared with controls. Long-term sedation with EOs increased superoxide dismutase, glutathione peroxidase and glutathione reductase activities in the brain, catalase in the liver, glutathione peroxidase and glutathione reductase in the gills and superoxide dismutase in the kidney. In general, nonprotein thiols content and total reactive antioxidant potential of tissues were higher after anesthesia and sedation with EOs compared with the control group. The concentrations of EOMS and EOCL used were effective at preventing a stress response and excess of reactive oxygen species formation. For these reasons, these substances may be recommended for use in the transportation of fish to improve survival and animal welfare. Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.

Potential Beneficial Effects of Probiotics on Human Migraine Headache: A Literature Review.

PubMed

Dai, Yu-Jie; Wang, Hai-Yan; Wang, Xi-Jian; Kaye, Alan D; Sun, Yong-Hai

2017-02-01

Recent studies have shown that migraine headache is often associated with concomitant gastrointestinal diseases. There is a higher prevalence of headaches in patients with gastrointestinal disorders. These associations between migraine and gastrointestinal disorders suggest a potential link to a bidirectional modulation of gut microbiota and brain function. The underlying working mechanistic links between migraine and gastrointestinal diseases may include increased intestinal epithelial permeability and inflammation. This review presents an overview of the relationship between gut microbiota and brain function, especially with regard to migraine headache. Literature review. Anesthesia and Operation Center, Department of Anesthesiology, Chinese PLA General Hospital. The present investigation included a PubMed search using the following terms: migraine headache, gut microbiota, brain function, and probiotics. In this literature review, we mainly discussed the relationship between gut microbiota and brain function, especially with regard to migraine headache. The potential effects of probiotics supplement on migraine headache were also included. There is limited evidence from clinical studies of the positive effects of probiotics in patients with migraine headache. Large-scale randomized, placebo-controlled clinical trials are warranted to evaluate the clinical efficacy and safety of probiotics in patients with migraine headache. Similar to migraine headache, disorders of the brain involving depression and anxiety have been demonstrated to be associated with increased gut permeability. An improvement in gut microbiota and reduction of inflammation can have positive effects on strengthening gut and brain function. Moreover, it can be inferred that probiotics may have a beneficial effect on the frequency and severity of migraine headache attacks. Large-scale randomized, placebo-controlled studies are warranted in the future to evaluate the clinical efficacy and safety of probiotics in patients with migraine headache.Key words: Migraine headache, gut microbiota, brain function, probiotics.

A Putative Multiple-Demand System in the Macaque Brain.

PubMed

Mitchell, Daniel J; Bell, Andrew H; Buckley, Mark J; Mitchell, Anna S; Sallet, Jerome; Duncan, John

2016-08-17

In humans, cognitively demanding tasks of many types recruit common frontoparietal brain areas. Pervasive activation of this "multiple-demand" (MD) network suggests a core function in supporting goal-oriented behavior. A similar network might therefore be predicted in nonhuman primates that readily perform similar tasks after training. However, an MD network in nonhuman primates has not been described. Single-cell recordings from macaque frontal and parietal cortex show some similar properties to human MD fMRI responses (e.g., adaptive coding of task-relevant information). Invasive recordings, however, come from limited prespecified locations, so they do not delineate a macaque homolog of the MD system and their positioning could benefit from knowledge of where MD foci lie. Challenges of scanning behaving animals mean that few macaque fMRI studies specifically contrast levels of cognitive demand, so we sought to identify a macaque counterpart to the human MD system using fMRI connectivity in 35 rhesus macaques. Putative macaque MD regions, mapped from frontoparietal MD regions defined in humans, were found to be functionally connected under anesthesia. To further refine these regions, an iterative process was used to maximize their connectivity cross-validated across animals. Finally, whole-brain connectivity analyses identified voxels that were robustly connected to MD regions, revealing seven clusters across frontoparietal and insular cortex comparable to human MD regions and one unexpected cluster in the lateral fissure. The proposed macaque MD regions can be used to guide future electrophysiological investigation of MD neural coding and in task-based fMRI to test predictions of similar functional properties to human MD cortex. In humans, a frontoparietal "multiple-demand" (MD) brain network is recruited during a wide range of cognitively demanding tasks. Because this suggests a fundamental function, one might expect a similar network to exist in nonhuman primates, but this remains controversial. Here, we sought to identify a macaque counterpart to the human MD system using fMRI connectivity. Putative macaque MD regions were functionally connected under anesthesia and were further refined by iterative optimization. The result is a network including lateral frontal, dorsomedial frontal, and insular and inferior parietal regions closely similar to the human counterpart. The proposed macaque MD regions can be useful in guiding electrophysiological recordings or in task-based fMRI to test predictions of similar functional properties to human MD cortex. Copyright © 2016 Mitchell et al.

Resting-state activity in development and maintenance of normal brain function.

PubMed

Pizoli, Carolyn E; Shah, Manish N; Snyder, Abraham Z; Shimony, Joshua S; Limbrick, David D; Raichle, Marcus E; Schlaggar, Bradley L; Smyth, Matthew D

2011-07-12

One of the most intriguing recent discoveries concerning brain function is that intrinsic neuronal activity manifests as spontaneous fluctuations of the blood oxygen level-dependent (BOLD) functional MRI signal. These BOLD fluctuations exhibit temporal synchrony within widely distributed brain regions known as resting-state networks. Resting-state networks are present in the waking state, during sleep, and under general anesthesia, suggesting that spontaneous neuronal activity plays a fundamental role in brain function. Despite its ubiquitous presence, the physiological role of correlated, spontaneous neuronal activity remains poorly understood. One hypothesis is that this activity is critical for the development of synaptic connections and maintenance of synaptic homeostasis. We had a unique opportunity to test this hypothesis in a 5-y-old boy with severe epileptic encephalopathy. The child developed marked neurologic dysfunction in association with a seizure disorder, resulting in a 1-y period of behavioral regression and progressive loss of developmental milestones. His EEG showed a markedly abnormal pattern of high-amplitude, disorganized slow activity with frequent generalized and multifocal epileptiform discharges. Resting-state functional connectivity MRI showed reduced BOLD fluctuations and a pervasive lack of normal connectivity. The child underwent successful corpus callosotomy surgery for treatment of drop seizures. Postoperatively, the patient's behavior returned to baseline, and he resumed development of new skills. The waking EEG revealed a normal background, and functional connectivity MRI demonstrated restoration of functional connectivity architecture. These results provide evidence that intrinsic, coherent neuronal signaling may be essential to the development and maintenance of the brain's functional organization.

Resting State Networks and Consciousness

PubMed Central

Heine, Lizette; Soddu, Andrea; Gómez, Francisco; Vanhaudenhuyse, Audrey; Tshibanda, Luaba; Thonnard, Marie; Charland-Verville, Vanessa; Kirsch, Murielle; Laureys, Steven; Demertzi, Athena

2012-01-01

In order to better understand the functional contribution of resting state activity to conscious cognition, we aimed to review increases and decreases in functional magnetic resonance imaging (fMRI) functional connectivity under physiological (sleep), pharmacological (anesthesia), and pathological altered states of consciousness, such as brain death, coma, vegetative state/unresponsive wakefulness syndrome, and minimally conscious state. The reviewed resting state networks were the DMN, left and right executive control, salience, sensorimotor, auditory, and visual networks. We highlight some methodological issues concerning resting state analyses in severely injured brains mainly in terms of hypothesis-driven seed-based correlation analysis and data-driven independent components analysis approaches. Finally, we attempt to contextualize our discussion within theoretical frameworks of conscious processes. We think that this “lesion” approach allows us to better determine the necessary conditions under which normal conscious cognition takes place. At the clinical level, we acknowledge the technical merits of the resting state paradigm. Indeed, fast and easy acquisitions are preferable to activation paradigms in clinical populations. Finally, we emphasize the need to validate the diagnostic and prognostic value of fMRI resting state measurements in non-communicating brain damaged patients. PMID:22969735

Methylphenidate Actively Induces Emergence from General Anesthesia

PubMed Central

Solt, Ken; Cotten, Joseph F.; Cimenser, Aylin; Wong, Kin F.K.; Chemali, Jessica J.; Brown, Emery N.

2011-01-01

Background Although accumulating evidence suggests that arousal pathways in the brain play important roles in emergence from general anesthesia, the roles of monoaminergic arousal circuits are unclear. In this study we tested the hypothesis that methylphenidate (an inhibitor of dopamine and norepinephrine transporters) induces emergence from isoflurane anesthesia. Methods Using adult rats we tested the effect of methylphenidate IV on time to emergence from isoflurane anesthesia. We then performed experiments to test separately for methylphenidate-induced changes in arousal and changes in minute ventilation. A dose-response study was performed to test for methylphenidate–induced restoration of righting during continuous isoflurane anesthesia. Surface electroencephalogram recordings were performed to observe neurophysiological changes. Plethysmography recordings and arterial blood gas analysis were performed to assess methylphenidate-induced changes in respiratory function. Droperidol IV was administered to test for inhibition of methylphenidate's actions. Results Methylphenidate decreased median time to emergence from 280 to 91 s. The median difference in time to emergence without compared to with methylphenidate was 200 [155, 331] s (median, [95% confidence interval]). During continuous inhalation of isoflurane, methylphenidate induced return of righting in a dose-dependent manner, induced a shift in electroencephalogram power from delta to theta, and induced an increase in minute ventilation. Administration of droperidol (0.5 mg/kg IV) prior to methylphenidate (5 mg/kg IV) largely inhibited methylphenidate-induced emergence behavior, electroencephalogram changes, and changes in minute ventilation. Conclusions Methylphenidate actively induces emergence from isoflurane anesthesia by increasing arousal and respiratory drive, possibly through activation of dopaminergic and adrenergic arousal circuits. Our findings suggest that methylphenidate may be clinically useful as an agent to reverse general anesthetic-induced unconsciousness and respiratory depression at the end of surgery. PMID:21934407

Factoring the brain signatures of anesthesia concentration and level of arousal across individuals.

PubMed

Barttfeld, Pablo; Bekinschtein, Tristan A; Salles, Alejo; Stamatakis, Emmanuel A; Adapa, Ram; Menon, David K; Sigman, Mariano

2015-01-01

Combining resting-state functional magnetic resonance imaging (fMRI) connectivity and behavioral analysis during sedation, we factored out general effects of the anesthetic drug propofol and a specific index of conscious report, participants' level of responsiveness. The factorial analysis shows that increasing concentration of propofol in blood specifically decreases the connectivity strength of fronto-parietal cortical loops. In contrast, loss of responsiveness is indexed by a functional disconnection between the thalamus and the frontal cortex, balanced by an increase in connectivity strength of the thalamus to the occipital and temporal regions of the cortex.

Factoring the brain signatures of anesthesia concentration and level of arousal across individuals

PubMed Central

Barttfeld, Pablo; Bekinschtein, Tristan A.; Salles, Alejo; Stamatakis, Emmanuel A.; Adapa, Ram; Menon, David K.; Sigman, Mariano

2015-01-01

Combining resting-state functional magnetic resonance imaging (fMRI) connectivity and behavioral analysis during sedation, we factored out general effects of the anesthetic drug propofol and a specific index of conscious report, participants’ level of responsiveness. The factorial analysis shows that increasing concentration of propofol in blood specifically decreases the connectivity strength of fronto-parietal cortical loops. In contrast, loss of responsiveness is indexed by a functional disconnection between the thalamus and the frontal cortex, balanced by an increase in connectivity strength of the thalamus to the occipital and temporal regions of the cortex. PMID:26509121

Impact of the Glymphatic System on the Kinetic and Distribution of Gadodiamide in the Rat Brain: Observations by Dynamic MRI and Effect of Circadian Rhythm on Tissue Gadolinium Concentrations.

PubMed

Taoka, Toshiaki; Jost, Gregor; Frenzel, Thomas; Naganawa, Shinji; Pietsch, Hubertus

2018-04-12

The glymphatic system is a recently hypothesized waste clearance system of the brain in which perivascular space constitutes a pathway similar to the lymphatic system in other body regions. Sleep and anesthesia are reported to influence the activity of the glymphatic system. Because rats are nocturnal animals, the glymphatic system is expected to be more active during the day. We attempted to elucidate the influence of the glymphatic system for intravenously injected gadodiamide in the rat brain by 2 experiments. One was a magnetic resonance imaging (MRI) experiment to evaluate the short-term dynamics of signal intensity changes after gadodiamide administration. The other was a quantification experiment to evaluate the concentration of retained gadolinium within the rat brain after repeated intravenous administration of gadodiamide at different times of day and levels of anesthesia. The imaging experiment was performed on 6 rats that received an intravenous injection of gadodiamide (1 mmol/kg) and dynamic MRI for 3 hours at 2.4-minute intervals. The time course of the signal intensity changes was evaluated for different brain structures. The tissue quantification experiment was performed on 24 rats divided into 4 groups by injection time (morning, late afternoon) and anesthesia (none, short, long) during administration. All animals received gadodiamide (1.8 mmol/kg, 8 times over 2 weeks). Gadolinium concentration of dissected brain tissues was quantified 5 weeks after the last administration by inductively coupled plasma mass spectrometry. In the imaging experiment, muscle and the fourth ventricle showed an instantaneous signal intensity increase immediately after gadodiamide injection. The signal curve of the cerebral cortex and deep cerebellar nuclei reached the peak signal intensity later than the fourth ventricle but earlier than that of the prepontine cistern. In the gadolinium quantification experiment, the concentration in the group with the morning injection showed a significantly lower concentration than the late afternoon injection group. The lowest tissue gadolinium concentrations were found in the groups injected in the morning during long anesthesia. Instantaneous transition of gadodiamide from blood to cerebrospinal fluid was indicated by dynamic MRI. The gadodiamide distribution to the cerebral cortex and deep cerebellar nuclei seemed to depend on both blood flow and cerebrospinal fluid. This confirms previous studies indicating that the cerebrospinal fluid is one potential pathway of gadolinium-based contrast agent entry into the brain. For the distribution and clearance of the gadodiamide from brain tissue, involvement of the glymphatic system seemed to be indicated in terms of the influence of sleep and anesthesia.

Risk in pediatric anesthesia.

PubMed

Paterson, Neil; Waterhouse, Peter

2011-08-01

Risk in pediatric anesthesia can be conveniently classified as minor or major. Major morbidity includes cardiac arrest, brain damage and death. Minor morbidity can be assessed by clinical audits with small patient samples. Major morbidity is rare. It is best assessed by very large clinical studies and by review of closed malpractice claims. Both minor and major morbidity occur most commonly in infants and children under three, especially those with severe co-morbidities. Knowledge of risk profiles in pediatric anesthesia is a starting point for the reduction of risk. © 2010 Blackwell Publishing Ltd.

Blood-brain barrier disruption and vascular damage induced by ultrasound bursts combined with microbubbles can be influenced by choice of anesthesia protocol

PubMed Central

McDannold, Nathan; Zhang, Yongzhi; Vykhodtseva, Natalia

2011-01-01

Numerous animal studies have demonstrated that ultrasound bursts combined with a microbubble-based ultrasound contrast agent can temporarily disrupt the blood-brain barrier (BBB) with little or no other apparent effects to the brain. As the BBB is a primary limitation to the use of most drugs in the brain, this method could enable a noninvasive means for targeted drug delivery in the brain. This work investigated whether BBB disruption and vessel damage when overexposure occurs can be influenced by choice of anesthesia protocol, which have different vasoactive effects. Four locations were sonicated transcranially in each brain of 16 rats using an unfocused 532 kHz piston transducer. Burst sonications (10 ms bursts applied at 1 Hz for 60 s) were combined with intravenous Definity (10 μl/kg) injections. BBB disruption was evaluated using contrast-enhanced MRI. Half of the animals were anesthetized with i.p. ketamine and xylazine, and the other half with inhaled isoflurane and oxygen. Over the range of exposure levels tested, MRI contrast enhancement was significantly higher (P<0.05) for animals anesthetized with ketamine/xylazine. Furthermore, the threshold for extensive erythrocyte extravasation was lower with ketamine/xylazine. These results suggest that BBB disruption and/or vascular damage can be affected by vascular or other factors that are influenced by different anesthesia protocol. These experiments may also have been influenced by the recently reported findings that the circulation time for perfluorocarbon microbubbles is substantially reduced when oxygen is used as the carrier gas. PMID:21645965

Legislative Enforcement of Nonconsensual Determination of Neurological (Brain) Death in Muslim Patients: A Violation of Religious Rights.

PubMed

Rady, Mohamed Y; Verheijde, Joseph L

2018-04-01

Death is defined in the Quran with a single criterion of irreversible separation of the ruh (soul) from the body. The Quran is a revelation from God to man, and the primary source of Islamic knowledge. The secular concept of death by neurological criteria, or brain death, is at odds with the Quranic definition of death. The validity of this secular concept has been contested scientifically and philosophically. To legitimize brain death for the purpose of organ donation and transplantation in Muslim communities, Chamsi-Pasha and Albar (concurring with the US President's Council on Bioethics) have argued that irreversible loss of capacity for consciousness and breathing (apneic coma) in brain death defines true death in accordance with Islamic sources. They have postulated that the absence of nafs (personhood) and nafas (breath) in apneic coma constitutes true death because of departure of the soul (ruh) from the body. They have also asserted that general anesthesia is routine in brain death before surgical procurement. Their argument is open to criticism because: (1) the ruh is described as the essence of life, whereas the nafs and nafas are merely human attributes; (2) unlike true death, the ruh is still present even with absent nafs and nafas in apneic coma; and (3) the routine use of general anesthesia indicates the potential harm to brain-dead donors from surgical procurement. Postmortem general anesthesia is not required for autopsy. Therefore, the conclusion must be that legislative enforcement of nonconsensual determination of neurological (brain) death and termination of life-support and medical treatment violates the religious rights of observant Muslims.

Recording Brain Electromagnetic Activity During the Administration of the Gaseous Anesthetic Agents Xenon and Nitrous Oxide in Healthy Volunteers.

PubMed

Pelentritou, Andria; Kuhlmann, Levin; Cormack, John; Woods, Will; Sleigh, Jamie; Liley, David

2018-01-13

Anesthesia arguably provides one of the only systematic ways to study the neural correlates of global consciousness/unconsciousness. However to date most neuroimaging or neurophysiological investigations in humans have been confined to the study of γ-Amino-Butyric-Acid-(GABA)-receptor-agonist-based anesthetics, while the effects of dissociative N-Methyl-D-Aspartate-(NMDA)-receptor-antagonist-based anesthetics ketamine, nitrous oxide (N2O) and xenon (Xe) are largely unknown. This paper describes the methods underlying the simultaneous recording of magnetoencephalography (MEG) and electroencephalography (EEG) from healthy males during inhalation of the gaseous anesthetic agents N2O and Xe. Combining MEG and EEG data enables the assessment of electromagnetic brain activity during anesthesia at high temporal, and moderate spatial, resolution. Here we describe a detailed protocol, refined over multiple recording sessions, that includes subject recruitment, anesthesia equipment setup in the MEG scanner room, data collection and basic data analysis. In this protocol each participant is exposed to varying levels of Xe and N2O in a repeated measures cross-over design. Following relevant baseline recordings participants are exposed to step-wise increasing inspired concentrations of Xe and N2O of 8, 16, 24 and 42%, and 16, 32 and 47% respectively, during which their level of responsiveness is tracked with an auditory continuous performance task (aCPT). Results are presented for a number of recordings to highlight the sensor-level properties of the raw data, the spectral topography, the minimization of head movements, and the unequivocal level dependent effects on the auditory evoked responses. This paradigm describes a general approach to the recording of electromagnetic signals associated with the action of different kinds of gaseous anesthetics, which can be readily adapted to be used with volatile and intravenous anesthetic agents. It is expected that the method outlined can contribute to the understanding of the macro-scale mechanisms of anesthesia by enabling methodological extensions involving source space imaging and functional network analysis.

Baseline brain energy supports the state of consciousness.

PubMed

Shulman, Robert G; Hyder, Fahmeed; Rothman, Douglas L

2009-07-07

An individual, human or animal, is defined to be in a conscious state empirically by the behavioral ability to respond meaningfully to stimuli, whereas the loss of consciousness is defined by unresponsiveness. PET measurements of glucose or oxygen consumption show a widespread approximately 45% reduction in cerebral energy consumption with anesthesia-induced loss of consciousness. Because baseline brain energy consumption has been shown by (13)C magnetic resonance spectroscopy to be almost exclusively dedicated to neuronal signaling, we propose that the high level of brain energy is a necessary property of the conscious state. Two additional neuronal properties of the conscious state change with anesthesia. The delocalized fMRI activity patterns in rat brain during sensory stimulation at a higher energy state (close to the awake) collapse to a contralateral somatosensory response at lower energy state (deep anesthesia). Firing rates of an ensemble of neurons in the rat somatosensory cortex shift from the gamma-band range (20-40 Hz) at higher energy state to <10 Hz at lower energy state. With the conscious state defined by the individual's behavior and maintained by high cerebral energy, measurable properties of that state are the widespread fMRI patterns and high frequency neuronal activity, both of which support the extensive interregional communication characteristic of consciousness. This usage of high brain energies when the person is in the "state" of consciousness differs from most studies, which attend the smaller energy increments observed during the stimulations that form the "contents" of that state.

Electroencephalographic Variation during End Maintenance and Emergence from Surgical Anesthesia

PubMed Central

MacColl, Jono N.; Illing, Sam; Sleigh, Jamie W.

2014-01-01

The re-establishment of conscious awareness after discontinuing general anesthesia has often been assumed to be the inverse of loss of consciousness. This is despite the obvious asymmetry in the initiation and termination of natural sleep. In order to characterize the restoration of consciousness after surgery, we recorded frontal electroencephalograph (EEG) from 100 patients in the operating room during maintenance and emergence from general anesthesia. We have defined, for the first time, 4 steady-state patterns of anesthetic maintenance based on the relative EEG power in the slow-wave (<14 Hz) frequency bands that dominate sleep and anesthesia. Unlike single-drug experiments performed in healthy volunteers, we found that surgical patients exhibited greater electroencephalographic heterogeneity while re-establishing conscious awareness after drug discontinuation. Moreover, these emergence patterns could be broadly grouped according to the duration and rapidity of transitions amongst these slow-wave dominated brain states that precede awakening. Most patients progressed gradually from a pattern characterized by strong peaks of delta (0.5–4 Hz) and alpha/spindle (8–14 Hz) power (‘Slow-Wave Anesthesia’) to a state marked by low delta-spindle power (‘Non Slow-Wave Anesthesia’) before awakening. However, 31% of patients transitioned abruptly from Slow-Wave Anesthesia to waking; they were also more likely to express pain in the post-operative period. Our results, based on sleep-staging classification, provide the first systematized nomenclature for tracking brain states under general anesthesia from maintenance to emergence, and suggest that these transitions may correlate with post-operative outcomes such as pain. PMID:25264892

Neurodevelopmental assessment after anesthesia in childhood: review of the literature and recommendations.

PubMed

Beers, Sue R; Rofey, Dana L; McIntyre, Katie A

2014-09-01

Preclinical studies have established that anesthesia is toxic to the brain in neonatal animals, but scant research investigates the neurodevelopmental effects of exposure to anesthesia. In this article, we discuss the issue of outcome measurement of children after anesthesia administered between infancy and approximately 4 years of age. Recent studies are reviewed with the goal of understanding the contributions and limitations of the extant literature with respect to neurodevelopmental outcome. A review of school-based information (academic achievement and learning disability characterization), which are most frequently applied to measure cognitive outcome in cohort studies, is provided. The strengths and limitations of this literature is reviewed, followed by a discussion of how future trials investigating neurodevelopmental outcome after anesthesia might be improved by procedures designed specifically to assess the status of the central nervous system. Neuropsychological assessment is described and proposed as a way to increase the validity and sensitivity of forthcoming studies that intend to evaluate the short- and long-term effects of exposure to anesthesia during infancy and early childhood.

A holistic approach to anesthesia-induced neurotoxicity and its implications for future mechanistic studies.

PubMed

Zanghi, Christine N; Jevtovic-Todorovic, Vesna

The year 2016 marked the 15th anniversary since anesthesia-induced developmental neurotoxicity and its resulting cognitive dysfunction were first described. Since that time, multiple scientific studies have supported these original findings and investigated possible mechanisms behind anesthesia-induced neurotoxicity. This paper reviews the existing mechanistic literature on anesthesia-induced neurotoxicity in the context of a holistic approach that emphasizes the importance of both neuronal and non-neuronal cells during early postnatal development. Sections are divided into key stages in early neural development; apoptosis, neurogenesis, migration, differentiation, synaptogenesis, gliogenesis, myelination and blood brain barrier/cerebrovasculature. In addition, the authors combine the established literature in the field of anesthesia-induced neurotoxicity with literature from other related scientific fields to speculate on the potential role of non-neuronal cells and to generate new future hypotheses for understanding anesthetic toxicity and its application to the practice of pediatric anesthesia. Copyright © 2017 Elsevier Inc. All rights reserved.

Dexmedetomidine Disrupts the Local and Global Efficiencies of Large-scale Brain Networks.

PubMed

Hashmi, Javeria A; Loggia, Marco L; Khan, Sheraz; Gao, Lei; Kim, Jieun; Napadow, Vitaly; Brown, Emery N; Akeju, Oluwaseun

2017-03-01

A clear understanding of the neural basis of consciousness is fundamental to research in clinical and basic neuroscience disciplines and anesthesia. Recently, decreased efficiency of information integration was suggested as a core network feature of propofol-induced unconsciousness. However, it is unclear whether this finding can be generalized to dexmedetomidine, which has a different molecular target. Dexmedetomidine was administered as a 1-μg/kg bolus over 10 min, followed by a 0.7-μg · kg · h infusion to healthy human volunteers (age range, 18 to 36 yr; n = 15). Resting-state functional magnetic resonance imaging data were acquired during baseline, dexmedetomidine-induced altered arousal, and recovery states. Zero-lag correlations between resting-state functional magnetic resonance imaging signals extracted from 131 brain parcellations were used to construct weighted brain networks. Network efficiency, degree distribution, and node strength were computed using graph analysis. Parcellated brain regions were also mapped to known resting-state networks to study functional connectivity changes. Dexmedetomidine significantly reduced the local and global efficiencies of graph theory-derived networks. Dexmedetomidine also reduced the average brain connectivity strength without impairing the degree distribution. Functional connectivity within and between all resting-state networks was modulated by dexmedetomidine. Dexmedetomidine is associated with a significant drop in the capacity for efficient information transmission at both the local and global levels. These changes result from reductions in the strength of connectivity and also manifest as reduced within and between resting-state network connectivity. These findings strengthen the hypothesis that conscious processing relies on an efficient system of information transfer in the brain.

Left Frontal Meningioangiomatosis Associated with Type IIIc Focal Cortical Dysplasia Causing Refractory Epilepsy and Literature Review.

PubMed

Roux, Alexandre; Mellerio, Charles; Lechapt-Zalcman, Emmanuelle; Still, Megan; Zerah, Michel; Bourgeois, Marie; Pallud, Johan

2018-06-01

We report the surgical management of a lesional drug-resistant epilepsy caused by a meningioangiomatosis associated with a type IIIc focal cortical dysplasia located in the left supplementary motor area in a young male patient. A first anatomically based partial surgical resection was performed on an 11-year-old under general anesthesia without intraoperative mapping, which allowed for postoperative seizure control (Engel IA) for 6 years. The patient then exhibited intractable right sensatory and aphasic focal onset seizures despite 2 appropriate antiepileptic drugs. A second functional-based surgical resection was performed using intraoperative corticosubcortical functional mapping with direct electrical stimulation under awake conditions. A complete surgical resection was performed, and a left partial supplementary motor area syndrome was observed. At 6 months postoperatively, the patient is seizure free (Engel IA) with an ongoing decrease in antiepileptic drug therapy. Intraoperative functional brain mapping can be applied to preserve the brain function and networks around a meningioangiomatosis to facilitate the resection of potentially epileptogenic perilesional dysplastic cortex and to tailor the extent of resection to functional boundaries. Copyright © 2018 Elsevier Inc. All rights reserved.

Isoflurane Impairs Low-Frequency Feedback but Leaves High-Frequency Feedforward Connectivity Intact in the Fly Brain.

PubMed

Cohen, Dror; van Swinderen, Bruno; Tsuchiya, Naotsugu

2018-01-01

Hierarchically organized brains communicate through feedforward (FF) and feedback (FB) pathways. In mammals, FF and FB are mediated by higher and lower frequencies during wakefulness. FB is preferentially impaired by general anesthetics in multiple mammalian species. This suggests FB serves critical functions in waking brains. The brain of Drosophila melanogaster (fruit fly) is also hierarchically organized, but the presence of FB in these brains is not established. Here, we studied FB in the fly brain, by simultaneously recording local field potentials (LFPs) from low-order peripheral structures and higher-order central structures. We analyzed the data using Granger causality (GC), the first application of this analysis technique to recordings from the insect brain. Our analysis revealed that low frequencies (0.1-5 Hz) mediated FB from the center to the periphery, while higher frequencies (10-45 Hz) mediated FF in the opposite direction. Further, isoflurane anesthesia preferentially reduced FB. Our results imply that the spectral characteristics of FF and FB may be a signature of hierarchically organized brains that is conserved from insects to mammals. We speculate that general anesthetics may induce unresponsiveness across species by targeting the mechanisms that support FB.

Isoflurane Impairs Low-Frequency Feedback but Leaves High-Frequency Feedforward Connectivity Intact in the Fly Brain

PubMed Central

2018-01-01

Abstract Hierarchically organized brains communicate through feedforward (FF) and feedback (FB) pathways. In mammals, FF and FB are mediated by higher and lower frequencies during wakefulness. FB is preferentially impaired by general anesthetics in multiple mammalian species. This suggests FB serves critical functions in waking brains. The brain of Drosophila melanogaster (fruit fly) is also hierarchically organized, but the presence of FB in these brains is not established. Here, we studied FB in the fly brain, by simultaneously recording local field potentials (LFPs) from low-order peripheral structures and higher-order central structures. We analyzed the data using Granger causality (GC), the first application of this analysis technique to recordings from the insect brain. Our analysis revealed that low frequencies (0.1–5 Hz) mediated FB from the center to the periphery, while higher frequencies (10–45 Hz) mediated FF in the opposite direction. Further, isoflurane anesthesia preferentially reduced FB. Our results imply that the spectral characteristics of FF and FB may be a signature of hierarchically organized brains that is conserved from insects to mammals. We speculate that general anesthetics may induce unresponsiveness across species by targeting the mechanisms that support FB. PMID:29541686

Blood-brain barrier disruption and vascular damage induced by ultrasound bursts combined with microbubbles can be influenced by choice of anesthesia protocol.

PubMed

McDannold, Nathan; Zhang, Yongzhi; Vykhodtseva, Natalia

2011-08-01

Numerous animal studies have demonstrated that ultrasound bursts combined with a microbubble-based ultrasound contrast agent can temporarily disrupt the blood-brain barrier (BBB) with little or no other apparent effects to the brain. As the BBB is a primary limitation to the use of most drugs in the brain, this method could enable a noninvasive means for targeted drug delivery in the brain. This work investigated whether BBB disruption and vessel damage when overexposure occurs can be influenced by choice of anesthesia protocol, which have different vasoactive effects. Four locations were sonicated transcranially in each brain of 16 rats using an unfocused 532 kHz piston transducer. Burst sonications (10 ms bursts applied at 1 Hz for 60 s) were combined with intravenous Definity (10 μl/kg) injections. BBB disruption was evaluated using contrast-enhanced MRI. Half of the animals were anesthetized with i.p. ketamine and xylazine, and the other half with inhaled isoflurane and oxygen. Over the range of exposure levels tested, MRI contrast enhancement was significantly higher (p < 0.05) for animals anesthetized with ketamine/xylazine. Furthermore, the threshold for extensive erythrocyte extravasation was lower with ketamine/xylazine. These results suggest that BBB disruption and/or vascular damage can be affected by vascular or other factors that are influenced by different anesthesia protocol. These experiments may also have been influenced by the recently reported findings that the circulation time for perfluorocarbon microbubbles is substantially reduced when oxygen is used as the carrier gas. Copyright © 2011 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Effects of isoflurane anesthesia on ensemble patterns of Ca2+ activity in mouse v1: reduced direction selectivity independent of increased correlations in cellular activity.

PubMed

Goltstein, Pieter M; Montijn, Jorrit S; Pennartz, Cyriel M A

2015-01-01

Anesthesia affects brain activity at the molecular, neuronal and network level, but it is not well-understood how tuning properties of sensory neurons and network connectivity change under its influence. Using in vivo two-photon calcium imaging we matched neuron identity across episodes of wakefulness and anesthesia in the same mouse and recorded spontaneous and visually evoked activity patterns of neuronal ensembles in these two states. Correlations in spontaneous patterns of calcium activity between pairs of neurons were increased under anesthesia. While orientation selectivity remained unaffected by anesthesia, this treatment reduced direction selectivity, which was attributable to an increased response to the null-direction. As compared to anesthesia, populations of V1 neurons coded more mutual information on opposite stimulus directions during wakefulness, whereas information on stimulus orientation differences was lower. Increases in correlations of calcium activity during visual stimulation were correlated with poorer population coding, which raised the hypothesis that the anesthesia-induced increase in correlations may be causal to degrading directional coding. Visual stimulation under anesthesia, however, decorrelated ongoing activity patterns to a level comparable to wakefulness. Because visual stimulation thus appears to 'break' the strength of pairwise correlations normally found in spontaneous activity under anesthesia, the changes in correlational structure cannot explain the awake-anesthesia difference in direction coding. The population-wide decrease in coding for stimulus direction thus occurs independently of anesthesia-induced increments in correlations of spontaneous activity.

Effects of Isoflurane Anesthesia on Ensemble Patterns of Ca2+ Activity in Mouse V1: Reduced Direction Selectivity Independent of Increased Correlations in Cellular Activity

PubMed Central

Goltstein, Pieter M.; Montijn, Jorrit S.; Pennartz, Cyriel M. A.

2015-01-01

Anesthesia affects brain activity at the molecular, neuronal and network level, but it is not well-understood how tuning properties of sensory neurons and network connectivity change under its influence. Using in vivo two-photon calcium imaging we matched neuron identity across episodes of wakefulness and anesthesia in the same mouse and recorded spontaneous and visually evoked activity patterns of neuronal ensembles in these two states. Correlations in spontaneous patterns of calcium activity between pairs of neurons were increased under anesthesia. While orientation selectivity remained unaffected by anesthesia, this treatment reduced direction selectivity, which was attributable to an increased response to the null-direction. As compared to anesthesia, populations of V1 neurons coded more mutual information on opposite stimulus directions during wakefulness, whereas information on stimulus orientation differences was lower. Increases in correlations of calcium activity during visual stimulation were correlated with poorer population coding, which raised the hypothesis that the anesthesia-induced increase in correlations may be causal to degrading directional coding. Visual stimulation under anesthesia, however, decorrelated ongoing activity patterns to a level comparable to wakefulness. Because visual stimulation thus appears to ‘break’ the strength of pairwise correlations normally found in spontaneous activity under anesthesia, the changes in correlational structure cannot explain the awake-anesthesia difference in direction coding. The population-wide decrease in coding for stimulus direction thus occurs independently of anesthesia-induced increments in correlations of spontaneous activity. PMID:25706867

Direct neuronal glucose uptake heralds activity-dependent increases in cerebral metabolism

PubMed Central

Lundgaard, Iben; Li, Baoman; Xie, Lulu; Kang, Hongyi; Sanggaard, Simon; Haswell, John Douglas R; Sun, Wei; Goldman, Siri; Blekot, Solomiya; Nielsen, Michael; Takano, Takahiro; Deane, Rashid; Nedergaard, Maiken

2015-01-01

Metabolically, the brain is a highly active organ that relies almost exclusively on glucose as its energy source. According to the astrocyte-to-neuron lactate shuttle hypothesis, glucose is taken up by astrocytes and converted to lactate, which is then oxidized by neurons. Here we show, using 2-photon imaging of a near-infrared 2-deoxyglucose analogue (2DG-IR), that glucose is taken up preferentially by neurons in awake behaving mice. Anesthesia suppressed neuronal 2DG-IR uptake and sensory stimulation was associated with a sharp increase in neuronal, but not astrocytic, 2DG-IR uptake. Moreover, hexokinase, which catalyze the first enzymatic steps in glycolysis, was highly enriched in neurons compared with astrocytes, in mouse as well as in human cortex. These observations suggest that brain activity and neuronal glucose metabolism are directly linked, and identifies the neuron as the principal locus of glucose uptake as visualized by functional brain imaging. PMID:25904018

Abdominal surgery activates nesfatin-1 immunoreactive brain nuclei in rats

PubMed Central

Stengel, Andreas; Goebel, Miriam; Wang, Lixin; Taché, Yvette

2011-01-01

Abdominal surgery-induced postoperative gastric ileus is well established to induce Fos expression in specific brain nuclei in rats within 2-h after surgery. However, the phenotype of activated neurons has not been thoroughly characterized. Nesfatin-1 was recently discovered in the rat hypothalamus as a new anorexigenic peptide that also inhibits gastric emptying and is widely distributed in rat brain autonomic nuclei suggesting an involvement in stress responses. Therefore, we investigated whether abdominal surgery activates nesfatin-1-immunoreactive (ir) neurons in the rat brain. Two hours after abdominal surgery with cecal palpation under short isoflurane anesthesia or anesthesia alone, rats were transcardially perfused and brains processed for double immunohistochemical labeling of Fos and nesfatin-1. Abdominal surgery, compared to anesthesia alone, induced Fos expression in neurons of the supraoptic nucleus (SON), paraventricular nucleus (PVN), locus coeruleus (LC), Edinger-Westphal nucleus (EW), rostral raphe pallidus (rRPa), nucleus of the solitary tract (NTS) and ventrolateral medulla (VLM). Double Fos/nesfatin-1 labeling showed that of the activated cells, 99% were nesfatin-1-immunoreactive in the SON, 91% in the LC, 82% in the rRPa, 74% in the EW and VLM, 71% in the anterior parvicellular PVN, 47% in the lateral magnocellular PVN, 41% in the medial magnocellular PVN, 14 % in the NTS and 9% in the medial parvicellular PVN. These data established nesfatin-1 immunoreactive neurons in specific hypothalamic and pontine nuclei as part of the neuronal response to abdominal surgery and suggest a possible implication of nesfatin-1 in the alterations of food intake and gastric transit associated with such a stressor. PMID:19944727

Management of parturients in active labor with Arnold Chiari malformation, tonsillar herniation, and syringomyelia

PubMed Central

Ghaly, Ramsis F.; Tverdohleb, Tatiana; Candido, Kenneth D.; Knezevic, Nebojsa Nick

2017-01-01

Background: Arnold-Chiari malformation Type 1 (ACM-1) in parturients is a topic of ongoing discussion between obstetricians and anesthesiologists. The primary unanswered question remains; How should the anesthesia provider proceed with labor analgesia and anesthesia for cesarean section when confronted with an advanced, asymptomatic, or minimally symptomatic case of ACM-1 during labor? Case Description: A 24-year-old, ASA II, G1P0 full-term parturient presented to Labor and Delivery for vaginal delivery. A diagnosis of ACM-1 was made 12 years ago when a brain magnetic resonance imaging (MRI) was performed for right-sided numbness following a rear-end motor vehicle collision. The patient had been asymptomatic since then and had been seen by an outside neurologist frequently for the past 10 years. During the anesthesia evaluation, it was noted that she had an exaggerated patellar reflex, and a questionable left-sided Babinski; subsequently, an MRI study was requested. Review of a brain MRI demonstrated an advanced form of ACM with a 1.7 cm transtonsillar herniation and a large syrinx extending from C1 down to C5. Following a discussion with the patient, family, and primary OB team, a plan for elective cesarean section was made per neurosurgical recommendations. This was conducted uneventfully under general anesthesia. The patient had no complaints in the post-anesthesia care unit. Conclusion: Unfamiliarity of health care providers with regards to ACM-1 parturients can be countered by increasing awareness of this condition throughout medical specialties involved in their care. The Ghaly Obstetric Guide to Arnold-Chiari malformation Type 1, along with proper training of anesthesia care providers regarding the specificities of ACM-1 parturients aids in better management and understanding of this complex condition. PMID:28217389

Management of parturients in active labor with Arnold Chiari malformation, tonsillar herniation, and syringomyelia.

PubMed

Ghaly, Ramsis F; Tverdohleb, Tatiana; Candido, Kenneth D; Knezevic, Nebojsa Nick

2017-01-01

Arnold-Chiari malformation Type 1 (ACM-1) in parturients is a topic of ongoing discussion between obstetricians and anesthesiologists. The primary unanswered question remains; How should the anesthesia provider proceed with labor analgesia and anesthesia for cesarean section when confronted with an advanced, asymptomatic, or minimally symptomatic case of ACM-1 during labor? A 24-year-old, ASA II, G1P0 full-term parturient presented to Labor and Delivery for vaginal delivery. A diagnosis of ACM-1 was made 12 years ago when a brain magnetic resonance imaging (MRI) was performed for right-sided numbness following a rear-end motor vehicle collision. The patient had been asymptomatic since then and had been seen by an outside neurologist frequently for the past 10 years. During the anesthesia evaluation, it was noted that she had an exaggerated patellar reflex, and a questionable left-sided Babinski; subsequently, an MRI study was requested. Review of a brain MRI demonstrated an advanced form of ACM with a 1.7 cm transtonsillar herniation and a large syrinx extending from C1 down to C5. Following a discussion with the patient, family, and primary OB team, a plan for elective cesarean section was made per neurosurgical recommendations. This was conducted uneventfully under general anesthesia. The patient had no complaints in the post-anesthesia care unit. Unfamiliarity of health care providers with regards to ACM-1 parturients can be countered by increasing awareness of this condition throughout medical specialties involved in their care. The Ghaly Obstetric Guide to Arnold-Chiari malformation Type 1, along with proper training of anesthesia care providers regarding the specificities of ACM-1 parturients aids in better management and understanding of this complex condition.

Time rescaling reproduces EEG behavior during transition from propofol anesthesia-induced unconsciousness to consciousness.

PubMed

Boussen, S; Spiegler, A; Benar, C; Carrère, M; Bartolomei, F; Metellus, P; Voituriez, R; Velly, L; Bruder, N; Trébuchon, A

2018-04-16

General anesthesia (GA) is a reversible manipulation of consciousness whose mechanism is mysterious at the level of neural networks leaving space for several competing hypotheses. We recorded electrocorticography (ECoG) signals in patients who underwent intracranial monitoring during awake surgery for the treatment of cerebral tumors in functional areas of the brain. Therefore, we recorded the transition from unconsciousness to consciousness directly on the brain surface. Using frequency resolved interferometry; we studied the intermediate ECoG frequencies (4-40 Hz). In the theoretical study, we used a computational Jansen and Rit neuron model to simulate recovery of consciousness (ROC). During ROC, we found that f increased by a factor equal to 1.62 ± 0.09, and δf varied by the same factor (1.61 ± 0.09) suggesting the existence of a scaling factor. We accelerated the time course of an unconscious EEG trace by an approximate factor 1.6 and we showed that the resulting EEG trace match the conscious state. Using the theoretical model, we successfully reproduced this behavior. We show that the recovery of consciousness corresponds to a transition in the frequency (f, δf) space, which is exactly reproduced by a simple time rescaling. These findings may perhaps be applied to other altered consciousness states.

Use of Propofol for Induction and Maintenance of Anesthesia in a King Penguin ( Aptenodytes patagonicus ) Undergoing Magnetic Resonance Imaging.

PubMed

Bigby, Sarah E; Carter, Jennifer E; Bauquier, Sébastien; Beths, Thierry

2016-09-01

Anesthesia protocols for patients with intracranial lesions need to provide hemodynamic stability, preserve cerebrovascular autoregulation, avoid increases in intracranial pressure, and facilitate a rapid recovery. Propofol total intravenous anesthesia (TIVA) maintains cerebral blood flow autoregulation and is considered superior to inhalant agents as an anesthetic protocol for patients with intracranial lesions. A propofol-based TIVA subsequent to premedication with medetomidine and diazepam was used in a king penguin ( Aptenodytes patagonicus ) undergoing magnetic resonance imaging of the brain after a new onset of seizures. This protocol provided a rapid and smooth induction and calm recovery in the penguin. When ventilation control is possible, propofol TIVA may be a superior choice to inhalant agents for anesthesia of birds with potential intracranial lesions.

A technique for administering xenon gas anesthesia during surgical procedures in mice.

PubMed

Ruder, Arne Mathias; Schmidt, Michaela; Ludiro, Alessia; Riva, Marco A; Gass, Peter

2014-11-01

Carrying out invasive procedures in animals requires the administration of anesthesia. Xenon gas offers advantages as an anesthetic agent compared with other agents, such as its protection of the brain and heart from hypoxia-induced damage. The high cost of xenon gas has limited its use as an anesthetic in animal experiments, however. The authors designed and constructed simple boxes for the induction and maintenance of xenon gas and isoflurane anesthesia in small rodents in order to minimize the amount of xenon gas that is wasted. While using their anesthesia delivery system to anesthetize pregnant mice undergoing caesarean sections, they measured the respiratory rates of the anesthetized mice, the survival of the pups and the percentages of oxygen and carbon dioxide within the system to confirm the system's safety.

The power of using functional fMRI on small rodents to study brain pharmacology and disease

PubMed Central

Jonckers, Elisabeth; Shah, Disha; Hamaide, Julie; Verhoye, Marleen; Van der Linden, Annemie

2015-01-01

Functional magnetic resonance imaging (fMRI) is an excellent tool to study the effect of pharmacological modulations on brain function in a non-invasive and longitudinal manner. We introduce several blood oxygenation level dependent (BOLD) fMRI techniques, including resting state (rsfMRI), stimulus-evoked (st-fMRI), and pharmacological MRI (phMRI). Respectively, these techniques permit the assessment of functional connectivity during rest as well as brain activation triggered by sensory stimulation and/or a pharmacological challenge. The first part of this review describes the physiological basis of BOLD fMRI and the hemodynamic response on which the MRI contrast is based. Specific emphasis goes to possible effects of anesthesia and the animal’s physiological conditions on neural activity and the hemodynamic response. The second part of this review describes applications of the aforementioned techniques in pharmacologically induced, as well as in traumatic and transgenic disease models and illustrates how multiple fMRI methods can be applied successfully to evaluate different aspects of a specific disorder. For example, fMRI techniques can be used to pinpoint the neural substrate of a disease beyond previously defined hypothesis-driven regions-of-interest. In addition, fMRI techniques allow one to dissect how specific modifications (e.g., treatment, lesion etc.) modulate the functioning of specific brain areas (st-fMRI, phMRI) and how functional connectivity (rsfMRI) between several brain regions is affected, both in acute and extended time frames. Furthermore, fMRI techniques can be used to assess/explore the efficacy of novel treatments in depth, both in fundamental research as well as in preclinical settings. In conclusion, by describing several exemplary studies, we aim to highlight the advantages of functional MRI in exploring the acute and long-term effects of pharmacological substances and/or pathology on brain functioning along with several methodological considerations. PMID:26539115

A Contemporary Analysis of Medicolegal Issues in Obstetric Anesthesia Between 2005 and 2015.

PubMed

Kovacheva, Vesela P; Brovman, Ethan Y; Greenberg, Penny; Song, Ellen; Palanisamy, Arvind; Urman, Richard D

2018-05-10

Detailed reviews of closed malpractice claims have provided insights into the most common events resulting in litigation and helped improve anesthesia care. In the past 10 years, there have been multiple safety advancements in the practice of obstetric anesthesia. We investigated the relationship among contributing factors, patient injuries, and legal outcome by analyzing a contemporary cohort of closed malpractice claims where obstetric anesthesiology was the principal defendant. The Controlled Risk Insurance Company (CRICO) is the captive medical liability insurer of the Harvard Medical Institutions that, in collaboration with other insurance companies and health care entities, contributes to the Comparative Benchmark System database for research purposes. We reviewed all (N = 106) closed malpractice cases related to obstetric anesthesia between 2005 and 2015 and compared the following classes of injury: maternal death and brain injury, neonatal death and brain injury, maternal nerve injury, and maternal major and minor injury. In addition, settled claims were compared to the cases that did not receive payment. χ, analysis of variance, Student t test, and Kruskal-Wallis tests were used for comparison between the different classes of injury. The largest number of claims, 54.7%, involved maternal nerve injury; 77.6% of these claims did not receive any indemnity payment. Cases involving maternal death or brain injury comprised 15.1% of all cases and were more likely to receive payment, especially in the high range (P = .02). The most common causes of maternal death or brain injury were high neuraxial blocks, embolic events, and failed intubation. Claims for maternal major and minor injury were least likely to receive payment (P = .02) and were most commonly (34.8%) associated with only emotional injury. Compared to the dropped/denied/dismissed claims, settled claims more frequently involved general anesthesia (P = .03), were associated with delays in care (P = .005), and took longer to resolve (3.2 vs 1.3 years; P < .0001). Obstetric anesthesia remains an area of significant malpractice liability. Opportunities for practice improvement in the area of severe maternal injury include timely recognition of high neuraxial block, availability of adequate resuscitative resources, and the use of advanced airway management techniques. Anesthesiologists should avoid delays in maternal care, establish clear communication, and follow their institutional policy regarding neonatal resuscitation. Prevention of maternal neurological injury should be directed toward performing neuraxial techniques at the lowest lumbar spine level possible and prevention/recognition of retained neuraxial devices.

Early exposure to general anesthesia with isoflurane downregulates inhibitory synaptic neurotransmission in the rat thalamus

PubMed Central

Joksovic, Pavle M.; Lunardi, Nadia; Jevtovic-Todorovic, Vesna; Todorovic, Slobodan M.

2015-01-01

Recent evidence supports the idea that common general anesthetics (GAs) such as isoflurane (Iso) and nitrous oxide (N2O; laughing gas) are neurotoxic and may harm the developing mammalian brain, including the thalamus; however, to date very little is known about how developmental exposure to GAs may affect synaptic transmission in the thalamus which, in turn, controls the function of thalamocortical circuitry. To address this issue we used in vitro patch-clamp recordings of evoked inhibitory postsynaptic currents (eIPSCs) from intact neurons of the nucleus reticularis thalami (nRT) in brain slices from rat pups (postnatal age P10-P18) exposed at age of P7 to clinically relevant GA combinations of Iso and N2O. We found that rats exposed to a combination of 0.75% Iso and 75% N2O display lasting reduction in the amplitude and faster decays of eIPSCs. Exposure to sub-anesthetic concentrations of 75% N2O alone or 0.75% Iso alone at P7 did not affect the amplitude of eIPSCs; however, Iso alone, but not N2O, significantly accelerated decay of eIPSCs. Anesthesia with 1.5% Iso alone decreased amplitudes, caused faster decay and decreased the paired-pulse ratio of eIPSCs. We conclude that anesthesia at P7 with Iso alone or in combination with N2O causes plasticity of eIPSCs in nRT neurons by both presynaptic and postsynaptic mechanisms. We hypothesize that changes in inhibitory synaptic transmission in the thalamus induced by GAs may contribute to altered neuronal excitability and consequently abnormal thalamocortical oscillations later in life. PMID:26048671

Isoflurane exerts neuroprotective actions at or near the time of severe traumatic brain injury.

PubMed

Statler, Kimberly D; Alexander, Henry; Vagni, Vincent; Holubkov, Richard; Dixon, C Edward; Clark, Robert S B; Jenkins, Larry; Kochanek, Patrick M

2006-03-03

Isoflurane improves outcome vs. fentanyl anesthesia, in experimental traumatic brain injury (TBI). We assessed the temporal profile of isoflurane neuroprotection and tested whether isoflurane confers benefit at the time of TBI. Adult, male rats were randomized to isoflurane (1%) or fentanyl (10 mcg/kg iv bolus then 50 mcg/kg/h) for 30 min pre-TBI. Anesthesia was discontinued, rats recovered to tail pinch, and TBI was delivered by controlled cortical impact. Immediately post-TBI, rats were randomized to 1 h of isoflurane, fentanyl, or no additional anesthesia, creating 6 anesthetic groups (isoflurane:isoflurane, isoflurane:fentanyl, isoflurane:none, fentanyl:isoflurane, fentanyl:fentanyl, fentanyl:none). Beam balance, beam walking, and Morris water maze (MWM) performances were assessed over post-trauma d1-20. Contusion volume and hippocampal survival were assessed on d21. Rats receiving isoflurane pre- and post-TBI exhibited better beam walking and MWM performances than rats treated with fentanyl pre- and any treatment post-TBI. All rats pretreated with isoflurane had better CA3 neuronal survival than rats receiving fentanyl pre- and post-TBI. In rats pretreated with fentanyl, post-traumatic isoflurane failed to affect function but improved CA3 neuronal survival vs. rats given fentanyl pre- and post-TBI. Post-traumatic isoflurane did not alter histopathological outcomes in rats pretreated with isoflurane. Rats receiving fentanyl pre- and post-TBI had the worst CA1 neuronal survival of all groups. Our data support isoflurane neuroprotection, even when used at the lowest feasible level before TBI (i.e., when discontinued with recovery to tail pinch immediately before injury). Investigators using isoflurane must consider its beneficial effects in the design and interpretation of experimental TBI research.

[Ophthalmic complications and local anesthesia. Pathophysiology and types of eye complications after intraoral dental anesthesia, and clinical recommendations].

PubMed

von Arx, Thomas; Lozanoff, Scott; Zinkernagel, Martin

2014-01-01

The present article reviews the different types of ophthalmologic complications following administration of intraoral local anesthesia. Since the first report by Brain in 1936, case reports about that topic have been published regularly in the literature. However, clinical studies evaluating the incidence of ophthalmologic complications after intraoral local anesthesia are rarely available. Previous data point to a frequency ranging from 0.03% to 0.13%. The most frequently described ophthalmologic complications include diplopia (double vision), ptosis (drooping of upper eyelid), and mydriasis (dilatation of pupil). Disorders that rather affect periorbital structures than the eye directly include facial paralysis and periorbital blanching (angiospasm). Diverse pathophysiologic mechanisms and causes have been reported in the literature, with the inadvertent intravascular administration of the local anesthetic considered the primary reason. The agent as well as the vasopressor is transported retrogradely via arteries or veins to the orbit or to periorbital structures (such as the cavernous sinus) with subsequent anesthesia of nerves and paralysis of muscles distant from the oral cavity. In general the ophthalmologic complications begin shortly after administration of the local anesthesia, and disappear once the local anesthesia has subsided.

Do anesthetics harm the developing human brain? An integrative analysis of animal and human studies.

PubMed

Lin, Erica P; Lee, Jeong-Rim; Lee, Christopher S; Deng, Meng; Loepke, Andreas W

Anesthetics that permit surgical procedures and stressful interventions have been found to cause structural brain abnormalities and functional impairment in immature animals, generating extensive concerns among clinicians, parents, and government regulators regarding the safe use of these drugs in young children. Critically important questions remain, such as the exact age at which the developing brain is most vulnerable to the effects of anesthetic exposure, whether a particular age exists beyond which anesthetics are devoid of long-term effects on the brain, and whether any specific exposure duration exists that does not lead to deleterious effects. Accordingly, the present analysis attempts to put the growing body of animal studies, which we identified to include >440 laboratory studies to date, into a translational context, by integrating the preclinical data on brain structure and function with clinical results attained from human neurocognitive studies, which currently exceed 30 studies. Our analysis demonstrated no clear exposure duration threshold below which no structural injury or subsequent cognitive abnormalities occurred. Animal data did not clearly identify a specific age beyond which anesthetic exposure did not cause any structural or functional abnormalities. Several potential mitigating strategies were found, however, no general anesthetic was identified that consistently lacked neurodegenerative properties and could be recommended over other anesthetics. It therefore is imperative, to expand efforts to devise safer anesthetic techniques and mitigating strategies, even before long-term alterations in brain development are unequivocally confirmed to occur in millions of young children undergoing anesthesia every year. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of carprofen on renal function during medetomidine-propofol-isoflurane anesthesia in dogs.

PubMed

Frendin, Jan H M; Boström, Ingrid M; Kampa, Naruepon; Eksell, Per; Häggström, Jens U; Nyman, Görel C

2006-12-01

To investigate effects of carprofen on indices of renal function and results of serum bio-chemical analyses and effects on cardiovascular variables during medetomidine-propofol-isoflurane anesthesia in dogs. 8 healthy male Beagles. A randomized crossover study was conducted with treatments including saline (0.9% NaCl) solution (0.08 mL/kg) and carprofen (4 mg/kg) administered IV. Saline solution or carprofen was administered 30 minutes before induction of anesthesia and immediately before administration of medetomidine (20 microg/kg, IM). Anesthesia was induced with propofol and maintained with inspired isoflurane in oxygen. Blood gas concentrations and ventilation were measured. Cardiovascular variables were continuously monitored via pulse contour cardiac output (CO) measurement. Renal function was assessed via glomerular filtration rate (GFR), renal blood flow (RBF), scintigraphy, serum biochemical analyses, urinalysis, and continuous CO measurements. Hematologic analysis was performed. Values did not differ significantly between the carprofen and saline solution groups. For both treatments, sedation and anesthesia caused changes in results of serum biochemical and hematologic analyses; a transient, significant increase in urine alkaline phosphatase activity; and blood flow diversion to the kidneys. The GFR increased significantly in both groups despite decreased CO, mean arterial pressure, and absolute RBF variables during anesthesia. Carprofen administered IV before anesthesia did not cause detectable, significant adverse effects on renal function during medetomidine-propofol-isoflurane anesthesia in healthy Beagles.

Disrupted brain network functional dynamics and hyper-correlation of structural and functional connectome topology in patients with breast cancer prior to treatment.

PubMed

Kesler, Shelli R; Adams, Marjorie; Packer, Melissa; Rao, Vikram; Henneghan, Ashley M; Blayney, Douglas W; Palesh, Oxana

2017-03-01

Several previous studies have demonstrated that cancer chemotherapy is associated with brain injury and cognitive dysfunction. However, evidence suggests that cancer pathogenesis alone may play a role, even in non-CNS cancers. Using a multimodal neuroimaging approach, we measured structural and functional connectome topology as well as functional network dynamics in newly diagnosed patients with breast cancer. Our study involved a novel, pretreatment assessment that occurred prior to the initiation of any cancer therapies, including surgery with anesthesia. We enrolled 74 patients with breast cancer age 29-65 and 50 frequency-matched healthy female controls who underwent anatomic and resting-state functional MRI as well as cognitive testing. Compared to controls, patients with breast cancer demonstrated significantly lower functional network dynamics ( p  = .046) and cognitive functioning ( p  < .02, corrected). The breast cancer group also showed subtle alterations in structural local clustering and functional local clustering ( p  < .05, uncorrected) as well as significantly increased correlation between structural global clustering and functional global clustering compared to controls ( p  = .03). This hyper-correlation between structural and functional topologies was significantly associated with cognitive dysfunction ( p  = .005). Our findings could not be accounted for by psychological distress and suggest that non-CNS cancer may directly and/or indirectly affect the brain via mechanisms such as tumor-induced neurogenesis, inflammation, and/or vascular changes, for example. Our results also have broader implications concerning the importance of the balance between structural and functional connectome properties as a potential biomarker of general neurologic deficit.

Caffeine Augments Anesthesia Neurotoxicity in the Fetal Macaque Brain.

PubMed

Noguchi, Kevin K; Johnson, Stephen A; Manzella, Francesca M; Masuoka, Kobe L; Williams, Sasha L; Martin, Lauren D; Dissen, Gregory A; Ikonomidou, Chrysanthy; Schenning, Katie J; Olney, John W; Brambrink, Ansgar M

2018-03-28

Caffeine is the most frequently used medication in premature infants. It is the respiratory stimulant of choice for apnea associated with prematurity and has been called the silver bullet in neonatology because of many proven benefits and few known risks. Research has revealed that sedative/anesthetic drugs trigger apoptotic death of neurons and oligodendrocytes in developing mammalian brains. Here we evaluated the influence of caffeine on the neurotoxicity of anesthesia in developing nonhuman primate brains. Fetal macaques (n = 7-8/group), at a neurodevelopmental age comparable to premature human infants, were exposed in utero for 5 hours to no drug (control), isoflurane, or isoflurane + caffeine and examined for evidence of apoptosis. Isoflurane exposure increased apoptosis 3.3 fold for neurons and 3.4 fold for oligodendrocytes compared to control brains. Isoflurane + caffeine caused neuronal apoptosis to increase 8.0 fold compared to control levels but did not augment oligoapoptosis. Neuronal death was particularly pronounced in the basal ganglia and cerebellum. Higher blood levels of caffeine within the range considered therapeutic and safe for human infants correlated with increased neuroapoptosis. Caffeine markedly augments neurotoxicity of isoflurane in the fetal macaque brain and challenges the assumption that caffeine is safe for premature infants.

Generalized seizures and transient contralateral hemiparesis following retrobulbar anesthesia: a case report.

PubMed

Dettoraki, Maria; Dimitropoulou, Chrisafoula; Nomikarios, Nikolaos; Moschos, Marilita M; Brοuzas, Dimitrios

2015-07-28

Retrobulbar block is a local anesthetic technique widely used for intraocular surgery. Although retrobulbar anesthesia is considered to be relatively safe, a number of serious adverse events have been reported. To our knowledge, immediate onset of generalized seizures with contralateral hemiparesis after retrobulbar anesthesia has not been reported. A 62-year-old Caucasian healthy male with a right eye retinal detachment was admitted for pars plana vitrectomy. During retrobulbar anesthesia with ropivacaine and before needle withdrawal, the patient developed twitching of the face which rapidly progressed to generalized tonic-clonic seizures. Arterial oxygen saturation decreased to 75 %. Chin lift was performed and 100 % oxygen was administrated via face mask, which increased saturation to 99 %. Midazolam 2 mg was administrated intravenously to control seizures. After cessation of seizures, left-sided hemiparesis was evident. Brain computed tomography and electroencephalogram were normal 3 h later. The patient underwent pars plana vitrectomy under general anesthesia 4 days later. Serious complications of local anesthesia for ophthalmic surgery are uncommon. We present a case in which generalized tonic-clonic seizures developed during retrobulbar anesthesia, followed by transient contralateral hemiparesis. The early onset of seizures indicated intra-arterial injection of the anesthetic. Our case suggested the need for close monitoring during the performance of retrobulbar anesthesia and the presence of well-trained personnel for early recognition and immediate management of the complications.

Developing a 3D Gestural Interface for Anesthesia-Related Human-Computer Interaction Tasks Using Both Experts and Novices.

PubMed

Jurewicz, Katherina A; Neyens, David M; Catchpole, Ken; Reeves, Scott T

2018-06-01

The purpose of this research was to compare gesture-function mappings for experts and novices using a 3D, vision-based, gestural input system when exposed to the same context of anesthesia tasks in the operating room (OR). 3D, vision-based, gestural input systems can serve as a natural way to interact with computers and are potentially useful in sterile environments (e.g., ORs) to limit the spread of bacteria. Anesthesia providers' hands have been linked to bacterial transfer in the OR, but a gestural input system for anesthetic tasks has not been investigated. A repeated-measures study was conducted with two cohorts: anesthesia providers (i.e., experts) ( N = 16) and students (i.e., novices) ( N = 30). Participants chose gestures for 10 anesthetic functions across three blocks to determine intuitive gesture-function mappings. Reaction time was collected as a complementary measure for understanding the mappings. The two gesture-function mapping sets showed some similarities and differences. The gesture mappings of the anesthesia providers showed a relationship to physical components in the anesthesia environment that were not seen in the students' gestures. The students also exhibited evidence related to longer reaction times compared to the anesthesia providers. Domain expertise is influential when creating gesture-function mappings. However, both experts and novices should be able to use a gesture system intuitively, so development methods need to be refined for considering the needs of different user groups. The development of a touchless interface for perioperative anesthesia may reduce bacterial contamination and eventually offer a reduced risk of infection to patients.

Identification of disappearing brain lesions with intraoperative magnetic resonance imaging prevents surgery.

PubMed

Sutherland, Christina S; Kelly, John Jp; Morrish, William; Sutherland, Garnette R

2010-10-01

Typically, neurosurgery is performed several weeks after diagnostic imaging. In the majority of cases, histopathology confirms the diagnosis of neoplasia. In a small number of cases, a different diagnosis is established or histopathology is nondiagnostic. The frequency with which these outcomes occur has not been established. To determine the frequency and outcome of disappearing brain lesions within a group of patients undergoing surgery for suspected brain tumor. Over the past decade, 982 patients were managed in the intraoperative magnetic resonance imaging unit at the University of Calgary, Calgary, Alberta, Canada. These patients have been prospectively evaluated. In 652 patients, a brain tumor was suspected. In 6 of the 652 patients, histopathology indicated a nontumor diagnosis. In 5 patients, intraoperative images, acquired after induction of anesthesia, showed complete or nearly complete resolution of the suspected tumor identified on diagnostic magnetic resonance imaging acquired 6 ± 4 (mean ± SD) weeks previously. Anesthesia was reversed, and the surgical procedure aborted. The lesions have not progressed with 6 ± 2 years of follow-up. Intraoperative magnetic resonance imaging prevented surgery on 5 patients with disappearing lesions.

[Acute brain expansion during emergency neck clipping surgery for cerebral aneurysms in a patient with dilated cardiomyopathy].

PubMed

Nakao, M; Kawaguchi, R; Nakatani, K; Niinai, H; Takezaki, T; Hanaki, C

1996-06-01

A 61-year-old male with coma and undiagnosed dilated cardiomyopathy received emergency cerebral aneurysm surgery. Anesthesia was induced with thiamylal, fentanyl and vecuronium and maintained with 66% N2O and 1.0% isoflurane. Five hundred ml of 20% mannitol was infused in 30 min. At the end of the infusion, hypotension occurred. Immediately after the injection of ephedrine, acute brain swelling was observed. The operation was switched to external decompression. Post-operative echocardiography revealed the presence of dilated cardiomyopathy (DCM). The ejection fraction was 34%. Two weeks later, the second operation was scheduled. The anesthesia was induced with fentanyl, midazolam and vecuronium and maintained with N2O and 0.7% isoflurane. Nitroglycerine, lidocaine, PGE1, dopamine and dobutamine were infused throughout the operation. Five hundred ml of 20% mannitol was infused in 60 min. There were no considerable hemodynamic changes and no episode of brain expansion during operation. We conclude that the rapid infusion of mannitol can trigger acute cardiac failure and brain edema in patients with DCM.

Toll-like receptor 4 knockout ameliorates neuroinflammation due to lung-brain interaction in mechanically ventilated mice.

PubMed

Chen, Ting; Chen, Chang; Zhang, Zongze; Zou, Yufeng; Peng, Mian; Wang, Yanlin

2016-08-01

Toll-like receptor 4 (TLR4) is a crucial receptor in the innate immune system, and increasing evidence supports its role in inflammation, stress, and tissue injury, including injury to the lung and brain. We aimed to investigate the effects of TLR4 on neuroinflammation due to the lung-brain interaction in mechanically ventilated mice. Male wild-type (WT) C57BL/6 and TLR4 knockout (TLR4 KO) mice were divided into three groups: (1) control group (C): spontaneous breathing; (2) anesthesia group (A): spontaneous breathing under anesthesia; and (3) mechanical ventilation group (MV): 6h of MV under anesthesia. The behavioral responses of mice were tested with fear conditioning tests. The histological changes in the lung and brain were assessed using hematoxylin-eosin (HE) staining. The level of TLR4 mRNA in tissue was measured using reverse transcription-polymerase chain reaction (RT-PCR). The levels of inflammatory cytokines were measured with an enzyme-linked immunosorbent assay (ELISA). Microgliosis, astrocytosis, and the TLR4 immunoreactivity in the hippocampus were measured by double immunofluorescence. MV mice exhibited impaired cognition, and this impairment was less severe in TLR4 KO mice than in WT mice. In WT mice, MV increased TLR4 mRNA expression in the lung and brain. MV induced mild lung injury, which was prevented in TLR4 KO mice. MV mice exhibited increased levels of inflammatory cytokines, increased microglia and astrocyte activation. Microgliosis was alleviated in TLR4 KO mice. MV mice exhibited increased TLR4 immunoreactivity, which was expressed in microglia and astrocytes. These results demonstrate that TLR4 is involved in neuroinflammation due to the lung-brain interaction and that TLR4 KO ameliorates neuroinflammation due to lung-brain interaction after prolonged MV. In addition, Administration of a TLR4 antagonist (100μg/mice) to WT mice also significantly attenuated neuroinflammation of lung-brain interaction due to prolonged MV. TLR4 antagonism may be a new and novel approach for the treatment and management of neuroinflammation in long-term mechanically ventilated patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Association Between a Single General Anesthesia Exposure Before Age 36 Months and Neurocognitive Outcomes in Later Childhood.

PubMed

Sun, Lena S; Li, Guohua; Miller, Tonya L K; Salorio, Cynthia; Byrne, Mary W; Bellinger, David C; Ing, Caleb; Park, Raymond; Radcliffe, Jerilynn; Hays, Stephen R; DiMaggio, Charles J; Cooper, Timothy J; Rauh, Virginia; Maxwell, Lynne G; Youn, Ahrim; McGowan, Francis X

2016-06-07

Exposure of young animals to commonly used anesthetics causes neurotoxicity including impaired neurocognitive function and abnormal behavior. The potential neurocognitive and behavioral effects of anesthesia exposure in young children are thus important to understand. To examine if a single anesthesia exposure in otherwise healthy young children was associated with impaired neurocognitive development and abnormal behavior in later childhood. Sibling-matched cohort study conducted between May 2009 and April 2015 at 4 university-based US pediatric tertiary care hospitals. The study cohort included sibling pairs within 36 months in age and currently 8 to 15 years old. The exposed siblings were healthy at surgery/anesthesia. Neurocognitive and behavior outcomes were prospectively assessed with retrospectively documented anesthesia exposure data. A single exposure to general anesthesia during inguinal hernia surgery in the exposed sibling and no anesthesia exposure in the unexposed sibling, before age 36 months. The primary outcome was global cognitive function (IQ). Secondary outcomes included domain-specific neurocognitive functions and behavior. A detailed neuropsychological battery assessed IQ and domain-specific neurocognitive functions. Parents completed validated, standardized reports of behavior. Among the 105 sibling pairs, the exposed siblings (mean age, 17.3 months at surgery/anesthesia; 9.5% female) and the unexposed siblings (44% female) had IQ testing at mean ages of 10.6 and 10.9 years, respectively. All exposed children received inhaled anesthetic agents, and anesthesia duration ranged from 20 to 240 minutes, with a median duration of 80 minutes. Mean IQ scores between exposed siblings (scores: full scale = 111; performance = 108; verbal = 111) and unexposed siblings (scores: full scale = 111; performance = 107; verbal = 111) were not statistically significantly different. Differences in mean IQ scores between sibling pairs were: full scale = -0.2 (95% CI, -2.6 to 2.9); performance = 0.5 (95% CI, -2.7 to 3.7); and verbal = -0.5 (95% CI, -3.2 to 2.2). No statistically significant differences in mean scores were found between sibling pairs in memory/learning, motor/processing speed, visuospatial function, attention, executive function, language, or behavior. Among healthy children with a single anesthesia exposure before age 36 months, compared with healthy siblings with no anesthesia exposure, there were no statistically significant differences in IQ scores in later childhood. Further study of repeated exposure, prolonged exposure, and vulnerable subgroups is needed.

Total Intravenous Anesthesia Including Ketamine versus Volatile Gas Anesthesia for Combat-related Operative Traumatic Brain Injury

DTIC Science & Technology

2008-07-01

receiving VGA with regard to Injury Severity Score, Glasgow Coma Scale score, base deficit, Head Abbreviated Injury Score, and craniectomy or craniotomy ...1, 2, or 3. Craniectomy or craniotomy was performed at the discretion of the neurosurgeon based on type of skull injury, severity of injury, and...perfectly on GCS ( 8, 8), base deficit ( 6, 6), Head Abbreviated Injury Score ( 3, 3) and craniectomy versus craniotomy . From these, subsets

Dynamic Repertoire of Intrinsic Brain States Is Reduced in Propofol-Induced Unconsciousness

PubMed Central

Liu, Xiping; Pillay, Siveshigan

2015-01-01

Abstract The richness of conscious experience is thought to scale with the size of the repertoire of causal brain states, and it may be diminished in anesthesia. We estimated the state repertoire from dynamic analysis of intrinsic functional brain networks in conscious sedated and unconscious anesthetized rats. Functional resonance images were obtained from 30-min whole-brain resting-state blood oxygen level-dependent (BOLD) signals at propofol infusion rates of 20 and 40 mg/kg/h, intravenously. Dynamic brain networks were defined at the voxel level by sliding window analysis of regional homogeneity (ReHo) or coincident threshold crossings (CTC) of the BOLD signal acquired in nine sagittal slices. The state repertoire was characterized by the temporal variance of the number of voxels with significant ReHo or positive CTC. From low to high propofol dose, the temporal variances of ReHo and CTC were reduced by 78%±20% and 76%±20%, respectively. Both baseline and propofol-induced reduction of CTC temporal variance increased from lateral to medial position. Group analysis showed a 20% reduction in the number of unique states at the higher propofol dose. Analysis of temporal variance in 12 anatomically defined regions of interest predicted that the largest changes occurred in visual cortex, parietal cortex, and caudate-putamen. The results suggest that the repertoire of large-scale brain states derived from the spatiotemporal dynamics of intrinsic networks is substantially reduced at an anesthetic dose associated with loss of consciousness. PMID:24702200

Vibration Anesthesia for Pain Reduction During Intralesional Steroid Injection for Keloid Treatment.

PubMed

Park, Kui Young; Lee, Yohan; Hong, Ji Yeon; Chung, Won Soon; Kim, Myeung Nam; Kim, Beom Joon

2017-05-01

Patients suffer significant pain during intralesional steroid injection treatment for keloids and hypertrophic scars. Vibration anesthesia has been shown to effectively and safely alleviate pain sensations, likely by reducing pain transmission from peripheral receptors to the brain. The objective was to evaluate the efficacy, safety, and patient satisfaction associated with vibration anesthesia for reducing pain during intralesional corticosteroid injection. The authors recruited 40 patients with 58 keloids who were scheduled to undergo intralesional triamcinolone acetonide (TA) injections. Half of each keloid was injected with concomitant vibration anesthesia, whereas the other half was injected without vibration anesthesia. Pain experienced by patients during both procedures was assessed according to visual analog scale (VAS) score. The authors also assessed procedure safety. The mean VAS score during intralesional TA injection therapy without vibration was 5.88 ± 2.34. By contrast, the same patients yielded a mean VAS score during intralesional TA injection therapy with vibration of 3.28 ± 1.85; the difference between the mean scores was significant (p < .05). Thirty-nine (97.5%) patients tolerated this therapy well. Vibration anesthesia is a promising option for reducing pain during keloid treatment with intralesional steroid injection.

[Introduction of translational research in omics science to clinical anesthesia].

PubMed

Sugino, Shigekazu; Hayase, Tomo; Yamakage, Michiaki

2013-03-01

Much progress has been made in omics research following completion of the Human Genome Project. This comprehensive analysis produced a new discipline (i.e., bioinformatics), and its findings contributed to the clinical practice of anesthesiology. Genomes of patients show genetic variations and may predict the sensitivity to anesthetics and analgesics, incidence of adverse effects, and intensity of postsurgical pain. Changes in the transcriptomes of patients may also reflect anesthesia-related expression profiles of various types of neurons in the brain, and information on such changes may contribute to molecular targeted therapy in anesthetized patients. In addition, novel epigenome research may explain why environments change the phenotypes of clinical anesthesia. We currently hypothesize that female gender is associated with DNA methylation in pain-related and vomiting-related gene promoter regions at the genome-wide level and that epigenetic mechanisms are involved in gender differences in anesthesia practice.

A Conserved Behavioral State Barrier Impedes Transitions between Anesthetic-Induced Unconsciousness and Wakefulness: Evidence for Neural Inertia

PubMed Central

Friedman, Eliot B.; Sun, Yi; Moore, Jason T.; Hung, Hsiao-Tung; Meng, Qing Cheng; Perera, Priyan; Joiner, William J.; Thomas, Steven A.; Eckenhoff, Roderic G.; Sehgal, Amita; Kelz, Max B.

2010-01-01

One major unanswered question in neuroscience is how the brain transitions between conscious and unconscious states. General anesthetics offer a controllable means to study these transitions. Induction of anesthesia is commonly attributed to drug-induced global modulation of neuronal function, while emergence from anesthesia has been thought to occur passively, paralleling elimination of the anesthetic from its sites in the central nervous system (CNS). If this were true, then CNS anesthetic concentrations on induction and emergence would be indistinguishable. By generating anesthetic dose-response data in both insects and mammals, we demonstrate that the forward and reverse paths through which anesthetic-induced unconsciousness arises and dissipates are not identical. Instead they exhibit hysteresis that is not fully explained by pharmacokinetics as previously thought. Single gene mutations that affect sleep-wake states are shown to collapse or widen anesthetic hysteresis without obvious confounding effects on volatile anesthetic uptake, distribution, or metabolism. We propose a fundamental and biologically conserved concept of neural inertia, a tendency of the CNS to resist behavioral state transitions between conscious and unconscious states. We demonstrate that such a barrier separates wakeful and anesthetized states for multiple anesthetics in both flies and mice, and argue that it contributes to the hysteresis observed when the brain transitions between conscious and unconscious states. PMID:20689589

Breakdown in the temporal and spatial organization of spontaneous brain activity during general anesthesia.

PubMed

Zhang, Jianfeng; Huang, Zirui; Chen, Yali; Zhang, Jun; Ghinda, Diana; Nikolova, Yuliya; Wu, Jinsong; Xu, Jianghui; Bai, Wenjie; Mao, Ying; Yang, Zhong; Duncan, Niall; Qin, Pengmin; Wang, Hao; Chen, Bing; Weng, Xuchu; Northoff, Georg

2018-05-01

Which temporal features that can characterize different brain states (i.e., consciousness or unconsciousness) is a fundamental question in the neuroscience of consciousness. Using resting-state functional magnetic resonance imaging (rs-fMRI), we investigated the spatial patterns of two temporal features: the long-range temporal correlations (LRTCs), measured by power-law exponent (PLE), and temporal variability, measured by standard deviation (SD) during wakefulness and anesthetic-induced unconsciousness. We found that both PLE and SD showed global reductions across the whole brain during anesthetic state comparing to wakefulness. Importantly, the relationship between PLE and SD was altered in anesthetic state, in terms of a spatial "decoupling." This decoupling was mainly driven by a spatial pattern alteration of the PLE, rather than the SD, in the anesthetic state. Our results suggest differential physiological grounds of PLE and SD and highlight the functional importance of the topographical organization of LRTCs in maintaining an optimal spatiotemporal configuration of the neural dynamics during normal level of consciousness. The central role of the spatial distribution of LRTCs, reflecting temporo-spatial nestedness, may support the recently introduced temporo-spatial theory of consciousness (TTC). © 2018 Wiley Periodicals, Inc.

Blood -brain barrier disruption was less under isoflurane than pentobarbital anesthesia via a PI3K/Akt pathway in early cerebral ischemia.

PubMed

Chi, Oak Z; Mellender, Scott J; Kiss, Geza K; Liu, Xia; Weiss, Harvey R

2017-05-01

One of the important factors altering the degree of blood-brain barrier (BBB) disruption in cerebral ischemia is the anesthetic used. The phosphoinositide 3-kinase (PI3K)/Akt signaling pathway has been reported to be involved in modulating BBB permeability and in isoflurane induced neuroprotection. This study was performed to compare the degree of BBB disruption in focal cerebral ischemia under isoflurane vs pentobarbital anesthesia and to determine whether inhibition of PI3K/Akt would affect the disruption in the early stage of focal cerebral ischemia. Permanent middle cerebral artery (MCA) occlusion was performed in rats under 1.4% isoflurane or pentobarbital (50mg/kg i.p.) anesthesia with controlled ventilation. In half of each group LY294002, which is a PI3K/Akt inhibitor, was applied on the ischemic cortex immediately after MCA occlusion. After one hour of MCA occlusion, the transfer coefficient (K i ) of 14 C-α-aminoisobutyric acid ( 14 C-AIB) was determined to quantify the degree of BBB disruption. MCA occlusion increased the K i both in the isoflurane and pentobarbital anesthetized rats. However, the value of K i was lower under isoflurane (11.5±6.0μL/g/min) than under pentobarbital (18.3±7.1μL/g/min) anesthesia. The K i of the contralateral cortex of the pentobarbital group was higher (+74%) than that of the isoflurane group. Application of LY294002 on the ischemic cortex increased the K i (+99%) only in the isoflurane group. The degree of BBB disruption by MCA occlusion was significantly lower under isoflurane than pentobarbital anesthesia in the early stage of cerebral ischemia. Our data demonstrated the importance of choice of anesthetics and suggest that PI3K/Akt signaling pathway plays a significant role in altering BBB disruption in cerebral ischemia during isoflurane but not during pentobarbital anesthesia. Copyright © 2017 Elsevier Inc. All rights reserved.

Neuroscience of water molecules: a salute to professor Linus Carl Pauling.

PubMed

Nakada, Tsutomu

2009-04-01

More than 35 years ago double Nobel laureate Linus Carl Pauling published a powerful model of the molecular mechanism of general anesthesia, generally referred to as the hydrate-microcrystal (aqueous-phase) theory. This hypothesis, based on the molecular behavior of water molecules, did not receive serious attention during Pauling's life time, when scientific tools for examining complex systems such as the brain were still in their infancy. The situation has since drastically changed, and, now, in the twenty first century, many scientific tools are available for examining different types of complex systems. The discovery of aquaporin-4, a subtype of water channel abundantly expressed in glial systems, further highlighted the concept that the dynamics of water molecules in the cerebral cortex play an important role in important physiological brain functions including consciousness and information processing.

Evaluation of drug effects on cerebral blood flow and glucose uptake in un-anesthetized and un-stimulated rats: application of free-moving apparatus enabling to keep rats free during PET/SPECT tracer injection and uptake.

PubMed

Sugita, Taku; Kondo, Yusuke; Ishino, Seigo; Mori, Ikuo; Horiguchi, Takashi; Ogawa, Mikako; Magata, Yasuhiro

2018-05-15

The purpose of this study is the development of novel fluorine-18-fluorodeoxyglucose (F-FDG)-PET and Tc-hexamethylpropylene amine oxime (HMPAO) SPECT methods with free-moving apparatus on conscious rats to investigate brain activity without the effects of anesthesia and tactual stimulation. We also assessed the sensitivity of the experimental system by an intervention study using fluoxetine as a reference drug. A catheter was inserted into the femoral vein and connected to a free-moving cannula system. After fluoxetine administration, the rats were given an injection of F-FDG or Tc-HMPAO via the intravenous cannula and released into a free-moving cage. After the tracer was trapped in the brain, the rats were anesthetized and scanned with PET or SPECT scanners. Then a volume of interest analysis and statistical parametric mapping were performed. We could inject the tracer without touching the rats, while keeping them conscious until the tracers were distributed and trapped in the brain using the developed system. The effects of fluoxetine on glucose uptake and cerebral blood flow were perceptively detected by volume of interest and statistical parametric mapping analysis. We successfully developed free-moving F-FDG-PET and Tc-HMPAO-SPECT imaging systems and detected detailed glucose uptake and cerebral blood flow changes in the conscious rat brain with fluoxetine administration. This system is expected to be useful to assess brain activity without the effects of anesthesia and tactual stimulation to evaluate drug effect or animal brain function.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/.

Where and When to Cut? Fluorescein Guidance for Brain Stem and Spinal Cord Tumor Surgery-Technical Note.

PubMed

Molina, Eric Suero; Stummer, Walter

2017-12-29

Spinal cord and brain stem lesions require a judicious approach with an optimized trajectory due to a clustering of functions on their surfaces. Intraoperative mapping helps locate function. To confidently locate such lesions, neuronavigation alone lacks the desired accuracy and is of limited use in the spinal cord. To evaluate the clinical value of fluoresceins for initial delineation of such critically located lesions. We evaluated fluorescein guidance in the surgical resection of lesions with blood-brain barrier disruption demonstrating contrast enhancement in magnet resonance imaging in the spinal cord and in the brain stem in 3 different patients. Two patients harbored a diffuse cervical and thoracic spinal cord lesion, respectively. Another patient suffered metastatic lesions in the brain stem and at the floor of the fourth ventricle. Low-dose fluorescein (4 mg/kg body weight) was applied after anesthesia induction and visualized using the Zeiss Pentero 900 Yellow560 filter (Carl Zeiss, Oberkochen, Germany). Fluorescein was helpful for locating lesions and for defining the best possible trajectory. During resection, however, we found unspecific propagation of fluorescein within the brain stem up to 6 mm within 3 h after application. As these lesions were otherwise distinguishable from surrounding tissue, monitoring resection was not an issue. Fluorescein guidance is a feasible tool for defining surgical entry zones when aiming for surgical removal of spinal cord and brain stem lesions. Unselective fluorescein extravasation cautions against using such methodology for monitoring completeness of resection. Providing the right timing, a window of pseudoselectivity could increase fluoresceins' clinical value in these cases. © Congress of Neurological Surgeons 2017.

Bispectral index, entropy, and quantitative electroencephalogram during single-agent xenon anesthesia.

PubMed

Laitio, Ruut M; Kaskinoro, Kimmo; Särkelä, Mika O K; Kaisti, Kaike K; Salmi, Elina; Maksimow, Anu; Långsjö, Jaakko W; Aantaa, Riku; Kangas, Katja; Jääskeläinen, Satu; Scheinin, Harry

2008-01-01

The aim was to evaluate the performance of anesthesia depth monitors, Bispectral Index (BIS) and Entropy, during single-agent xenon anesthesia in 17 healthy subjects. After mask induction with xenon and intubation, anesthesia was continued with xenon only. BIS, State Entropy and Response Entropy, and electroencephalogram were monitored throughout induction, steady-state anesthesia, and emergence. The performance of BIS, State Entropy, and Response Entropy were evaluated with prediction probability, sensitivity, and specificity analyses. The power spectrum of the raw electroencephalogram signal was calculated. The mean (SD) xenon concentration during anesthesia was 66.4% (2.4%). BIS, State Entropy, and Response Entropy demonstrated low prediction probability values at loss of response (0.455, 0.656, and 0.619) but 1 min after that the values were high (0.804, 0.941, and 0.929). Thereafter, equally good performance was demonstrated for all indices. At emergence, the prediction probability values to distinguish between steady-state anesthesia and return of response for BIS, State Entropy, and Response Entropy were 0.988, 0.892, and 0.992. No statistical differences between the performances of the monitors were observed. Quantitative electroencephalogram analyses showed generalized increase in total power (P < 0.001), delta (P < 0.001) and theta activity (P < 0.001), and increased alpha activity (P = 0.003) in the frontal brain regions. Electroencephalogram-derived depth of sedation indices BIS and Entropy showed a delay to detect loss of response during induction of xenon anesthesia. Both monitors performed well in distinguishing between conscious and unconscious states during steady-state anesthesia. Xenon-induced changes in electroencephalogram closely resemble those induced by propofol.

Voluntary running enhances glymphatic influx in awake behaving, young mice.

PubMed

von Holstein-Rathlou, Stephanie; Petersen, Nicolas Caesar; Nedergaard, Maiken

2018-01-01

Vascular pathology and protein accumulation contribute to cognitive decline, whereas exercise can slow vascular degeneration and improve cognitive function. Recent investigations suggest that glymphatic clearance measured in aged mice while anesthetized is enhanced following exercise. We predicted that exercise would also stimulate glymphatic activity in awake, young mice with higher baseline glymphatic function. Therefore, we assessed glymphatic function in young female C57BL/6J mice following five weeks voluntary wheel running and in sedentary mice. The active mice ran a mean distance of 6km daily. We injected fluorescent tracers in cisterna magna of awake behaving mice and in ketamine/xylazine anesthetized mice, and later assessed tracer distribution in coronal brain sections. Voluntary exercise consistently increased CSF influx during wakefulness, primarily in the hypothalamus and ventral parts of the cortex, but also in the middle cerebral artery territory. While glymphatic activity was higher under ketamine/xylazine anesthesia, we saw a decrease in glymphatic function during running in awake mice after five weeks of wheel running. In summary, daily running increases CSF flux in widespread areas of the mouse brain, which may contribute to the pro-cognitive effects of exercise. Copyright © 2017 Elsevier B.V. All rights reserved.

Anesthesia and the developing brain.

PubMed

Aker, John; Block, Robert I; Biddle, Chuck

2015-04-01

Despite the profound evolution in the safety and efficacy of neonatal and pediatric anesthesia, questions remain concerning the long-term neurotoxic and neurocognitive effects of the drugs used in anesthetic care. A variety of prospective animal models and retrospective human studies exist that inconsistently demonstrate a detrimental effect of early life exposure to anesthetic drugs and subsequent learning performance. Limitations associated with both non-human and human observational studies are critiqued. Research currently underway is briefly described. A framework for discussing the relevant issues with concerned parents is presented.

Blood-Brain Barrier Disruption Caused by Ultrasound Bursts Combined with Microbubbles Depends on Anesthesia

NASA Astrophysics Data System (ADS)

McDannold, Nathan; Zhang, Yongzhi; Vykhodtseva, Natalia

2011-09-01

Prior works on BBB disruption via inter-arterial infusions of osmotic agents have shown a strong dependence on anesthesia. Here, we investigated whether different anesthesia agents can affect ultrasound-induced BBB disruption. A piston transducer fired through a rubber aperture (frequency: 532 kHz, diameter: 4 cm, aperture diameter: 16 mm) was used to generate the ultrasound fields, and sonications combined with an ultrasound contrast agent were performed at 5 power levels. BBB disruption was quantified by measuring the MRI contrast enhancement in T1-weighted MRI, and erythrocyte extravasation characterized in light microscopy. For each exposure level tested, experiments performed with ketamine/xylazine resulted in significantly greater (P<0.05) enhancement than with isoflurane/oxygen. The onset of severe red blood cell extravasation occurred at lower power levels with ketamine/xylazine. These results suggest ultrasound-induced BBB disruption can depend on anesthesia agent, possibly due effects on the vasculature. These results suggest that care is needed in comparing experiments with different anesthesia agents and physiological factors need to be considered with ultrasound-induced BBB disruption.

Effects of carprofen on renal function and results of serum biochemical and hematologic analyses in anesthetized dogs that had low blood pressure during anesthesia.

PubMed

Boström, Ingrid M; Nyman, Görel C; Lord, Peter E; Häggström, Jens; Jones, Bernt E V; Bohlin, Henrik P

2002-05-01

To investigate effects of IV administered carprofen on indices of renal function and results of serum biochemical and hematologic analyses in dogs anesthetized with acepromazine-thiopentone-isoflurane that had low blood pressure during anesthesia. 6 healthy Beagles. A randomized crossover study was conducted, using the following treatments: saline (0.9% NaCl solution)-saline, saline-carprofen, and carprofen-saline. Saline (0.08 ml/kg) and carprofen (4 mg/kg) were administered IV. The first treatment was administered 30 minutes before induction of anesthesia and immediately before administration of acepromazine (0.1 mg/kg, IM). Anesthesia was induced with thiopentone (25 mg/ml, IV) and maintained with inspired isoflurane (2% in oxygen). The second treatment was administered 30 minutes after onset of inhalation anesthesia. Blood gases, circulation, and ventilation were monitored. Renal function was assessed by glomerular filtration rate (GFR), using scintigraphy, serum biochemical analyses, and urinalysis. Hematologic analysis was performed. Statistical analysis was conducted, using ANOVA or Friedman ANOVA. Values did not differ significantly among the 3 treatments. For all treatments, sedation and anesthesia caused changes in results of serum biochemical and hematologic analyses, a decrease in mean arterial blood pressure to 65 mm Hg, an increase of 115 pmol/L in angiotensin II concentration, and an increase of 100 seconds in time required to reach maximum activity counts during scintigraphy. Carprofen administered IV before or during anesthesia did not cause detectable significant adverse effects on renal function or results of serum biochemical and hematologic analyses in healthy Beagles with low blood pressure during anesthesia.

Thoracic Epidural Anesthesia Reduces Right Ventricular Systolic Function With Maintained Ventricular-Pulmonary Coupling.

PubMed

Wink, Jeroen; de Wilde, Rob B P; Wouters, Patrick F; van Dorp, Eveline L A; Veering, Bernadette Th; Versteegh, Michel I M; Aarts, Leon P H J; Steendijk, Paul

2016-10-18

Blockade of cardiac sympathetic fibers by thoracic epidural anesthesia may affect right ventricular function and interfere with the coupling between right ventricular function and right ventricular afterload. Our main objectives were to study the effects of thoracic epidural anesthesia on right ventricular function and ventricular-pulmonary coupling. In 10 patients scheduled for lung resection, right ventricular function and its response to increased afterload, induced by temporary, unilateral clamping of the pulmonary artery, was tested before and after induction of thoracic epidural anesthesia using combined pressure-conductance catheters. Thoracic epidural anesthesia resulted in a significant decrease in right ventricular contractility (ΔESV 25 : +25.5 mL, P=0.0003; ΔEes: -0.025 mm Hg/mL, P=0.04). Stroke work, dP/dt MAX , and ejection fraction showed a similar decrease in systolic function (all P<0.05). A concomitant decrease in effective arterial elastance (ΔEa: -0.094 mm Hg/mL, P=0.004) yielded unchanged ventricular-pulmonary coupling. Cardiac output, systemic vascular resistance, and mean arterial blood pressure were unchanged. Clamping of the pulmonary artery significantly increased afterload (ΔEa: +0.226 mm Hg/mL, P<0.001). In response, right ventricular contractility increased (ΔESV 25 : -26.6 mL, P=0.0002; ΔEes: +0.034 mm Hg/mL, P=0.008), but ventricular-pulmonary coupling decreased (Δ(Ees/Ea) = -0.153, P<0.0001). None of the measured indices showed significant interactive effects, indicating that the effects of increased afterload were the same before and after thoracic epidural anesthesia. Thoracic epidural anesthesia impairs right ventricular contractility but does not inhibit the native positive inotropic response of the right ventricle to increased afterload. Right ventricular-pulmonary arterial coupling was decreased with increased afterload but not affected by the induction of thoracic epidural anesthesia. URL: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2844. Unique identifier: NTR2844. © 2016 American Heart Association, Inc.

Retinopathy of prematurity and brain damage in the very preterm newborn.

PubMed

Allred, Elizabeth N; Capone, Antonio; Fraioli, Anthony; Dammann, Olaf; Droste, Patrick; Duker, Jay; Gise, Robert; Kuban, Karl; Leviton, Alan; O'Shea, T Michael; Paneth, Nigel; Petersen, Robert; Trese, Michael; Stoessel, Kathleen; Vanderveen, Deborah; Wallace, David K; Weaver, Grey

2014-06-01

To explain why very preterm newborns who develop retinopathy of prematurity (ROP) appear to be at increased risk of abnormalities of both brain structure and function. A total of 1,085 children born at <28 weeks' gestation had clinically indicated retinal examinations and had a developmental assessment at 2 years corrected age. Relationships between ROP categories and brain abnormalities were explored using logistic regression models with adjustment for potential confounders. The 173 children who had severe ROP, defined as prethreshold ROP (n = 146) or worse (n = 27) were somewhat more likely than their peers without ROP to have brain ultrasound lesions or cerebral palsy. They were approximately twice as likely to have very low Bayley Scales scores. After adjusting for risk factors common to both ROP and brain disorders, infants who developed severe ROP were at increased risk of low Bayley Scales only. Among children with prethreshold ROP, exposure to anesthesia was not associated with low Bayley Scales. Some but not all of the association of ROP with brain disorders can be explained by common risk factors. Most of the increased risks of very low Bayley Scales associated with ROP are probably not a consequence of exposure to anesthetic agents. Copyright © 2014 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

[Characteristics of anesthesia in patients with MELAS syndrome: Case report of anesthesia in video-assisted thoracoscopy].

PubMed

Haas, A; Wappler, F

2015-10-01

The mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome is a disease triggered by a disorder in energy production within mitochondria. The cause of this syndrome is a mutation in the mitochondrial DNA where in 80% of cases an A-to-G mutation is present at nucleotide 3243 and with a prevalence of 18.4/100,000 in the population. Predominantly affected are organ systems with a high energy metabolism, such as the heart, brain and musculature. During the premedication visit a thorough patient history and examination with respect to neurological impairments must be carried out. Epilepsy and the appropriate permanent medication lead to possible alterations in effectiveness of anesthetics and muscle relaxants which are difficult to predict. An extensive patient cardiac history and a preoperative electrocardiogram (ECG) for an appraisal of possible disorders in the cardiac conduction system and when necessary extended cardiac diagnostics, are recommended. The monitoring must be adapted depending on the functional limitations and the forthcoming intervention and when necessary a postoperative surveillance in an intensive care unit should be initiated. Knowledge of the special features of MELAS syndrome in association with a consideration of the characteristics of anesthesia in MELAS patients and an individually adapted intensified perioperative surveillance, can contribute to a reduction in perioperative morbidity in patients suffering from MELAS syndrome.

The effect of surgical and psychological stress on learning and memory function in aged C57BL/6 mice.

PubMed

Zhang, C; Li, C; Xu, Z; Zhao, S; Li, P; Cao, J; Mi, W

2016-04-21

Postoperative cognitive dysfunction (POCD) is an important complication following major surgery and general anesthesia in older patients. However, the etiology of POCD remains largely to be determined. It is unknown how surgical stress and psychological stress affect the postoperative learning and memory function in geriatric patients. We therefore established a pre-clinical model in aged C57BL/6 mice and aimed to investigate the effects of surgical stress and psychological stress on learning and memory function and the possible roles of the protein kinase B/mammalian target of rapamycin (AKT/mTOR) pathway. The surgical stress was induced by abdominal surgery under local anesthesia, and the psychological stress was induced by a communication box. Cognitive functions and markers of the AKT/mTOR pathway were assessed at 1, 3 and 7 days following the stress. The impairments of learning and memory function existed for up to 7 days following surgical stress and surgical stress plus psychological stress, whereas the psychological stress did not affect the cognitive function alone or combined with surgical stress. Analysis of brain tissue revealed a significant involvement of the AKT/mTOR pathway in the impairment of cognition. These data suggested that surgical stress could induce cognitive impairment in aged mice and perioperative psychological stress is not a constitutive factor of POCD. The AKT/mTOR pathway is likely involved as one of the underlying mechanisms of the development of POCD. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Markerless rat head motion tracking using structured light for brain PET imaging of unrestrained awake small animals

NASA Astrophysics Data System (ADS)

Miranda, Alan; Staelens, Steven; Stroobants, Sigrid; Verhaeghe, Jeroen

2017-03-01

Preclinical positron emission tomography (PET) imaging in small animals is generally performed under anesthesia to immobilize the animal during scanning. More recently, for rat brain PET studies, methods to perform scans of unrestrained awake rats are being developed in order to avoid the unwanted effects of anesthesia on the brain response. Here, we investigate the use of a projected structure stereo camera to track the motion of the rat head during the PET scan. The motion information is then used to correct the PET data. The stereo camera calculates a 3D point cloud representation of the scene and the tracking is performed by point cloud matching using the iterative closest point algorithm. The main advantage of the proposed motion tracking is that no intervention, e.g. for marker attachment, is needed. A manually moved microDerenzo phantom experiment and 3 awake rat [18F]FDG experiments were performed to evaluate the proposed tracking method. The tracking accuracy was 0.33 mm rms. After motion correction image reconstruction, the microDerenzo phantom was recovered albeit with some loss of resolution. The reconstructed FWHM of the 2.5 and 3 mm rods increased with 0.94 and 0.51 mm respectively in comparison with the motion-free case. In the rat experiments, the average tracking success rate was 64.7%. The correlation of relative brain regional [18F]FDG uptake between the anesthesia and awake scan reconstructions was increased from on average 0.291 (not significant) before correction to 0.909 (p  <  0.0001) after motion correction. Markerless motion tracking using structured light can be successfully used for tracking of the rat head for motion correction in awake rat PET scans.

Perifocal and remote blood-brain barrier disruption in cortical photothrombotic ischemic lesion and its modulation by the choice of anesthesia.

PubMed

Krysl, D; Deykun, K; Lambert, L; Pokorny, J; Mares, J

2012-04-01

We assessed blood-brain barrier (BBB) disruption in early stage of photothrombotic focal cerebral ischemia in the rat. We specifically looked for contralateral changes in BBB permeability and tested the influence of two anesthetics on the results. Adult Wistar rats were randomly anesthetized with pentobarbital (PB) or ketamine-xylazine (KX). Rats received intravenously (i.v.) Rose Bengal followed by Evans Blue (EB). Stereotactically defined spots on denuded skull were irradiated by laser (532 nm) for 18 min. Twenty four hours later, rats were killed, brains perfused, fixated, sectioned and slices analyzed by fluorescence microscopy. Volume of necrosis and volume of EB-albumin extravasation were calculated. Evidence of BBB breakdown in remote brain areas was sought and compared to sham handled controls. BBB disruption was consistently present, frequently with EB-albumin accumulating cells. Total lesion volume did not significantly differ among groups (TLVPB=9.4±1.3 mm³ vs. TLVKX=8.3±2.1 mm³); same was true for the volume of necrosis (NVPB=5.1±0.7 mm³ vs. NVKX=6.3±1.9 mm³). However, volume of EB-albumin extravasation area was significantly smaller in KX group (EBEVPB=4.3±0.8 mm³ vs. EBEVKX=2.0±0.5 mm³; p=0.0293). Median background EB-fluorescence signal density was higher in PB group (p<0.0001). Furthermore, regional increase in EB-fluorescence was found in two animals in PB group. Our study shows that anesthesia with NMDA-antagonist ketamine and α2-adrenergic agonist xylazine may reduce BBB breakdown in photothrombosis. Pentobarbital anesthesia lead to increased BBB permeability in the contralateral hemisphere.

Monoterpenoids (thymol, carvacrol and S-(+)-linalool) with anesthetic activity in silver catfish (Rhamdia quelen): evaluation of acetylcholinesterase and GABAergic activity

PubMed Central

Bianchini, A.E.; Garlet, Q.I.; da Cunha, J.A.; Bandeira, G.; Brusque, I.C.M.; Salbego, J.; Heinzmann, B.M.; Baldisserotto, B.

2017-01-01

This study evaluated the anesthetic potential of thymol and carvacrol, and their influence on acetylcholinesterase (AChE) activity in the muscle and brain of silver catfish (Rhamdia quelen). The AChE activity of S-(+)-linalool was also evaluated. We subsequently assessed the effects of thymol and S-(+)-linalool on the GABAergic system. Fish were exposed to thymol and carvacrol (25, 50, 75, and 100 mg/L) to evaluate time for anesthesia and recovery. Both compounds induced sedation at 25 mg/L and anesthesia with 50–100 mg/L. However, fish exposed to carvacrol presented strong muscle contractions and mortality. AChE activity was increased in the brain of fish at 50 mg/L carvacrol and 100 mg/L thymol, and decreased in the muscle at 100 mg/L carvacrol. S-(+)-linalool did not alter AChE activity. Anesthesia with thymol was reversed by exposure to picrotoxin (GABAA antagonist), similar to the positive control propofol, but was not reversed by flumazenil (antagonist of benzodiazepine binding site), as observed for the positive control diazepam. Picrotoxin did not reverse the effect of S-(+)-linalool. Thymol exposure at 50 mg/L is more suitable than carvacrol for anesthesia in silver catfish, because this concentration did not cause any mortality or interference with AChE activity. Thymol interacted with GABAA receptors, but not with the GABAA/benzodiazepine site. In contrast, S-(+)-linalool did not act in GABAA receptors in silver catfish. PMID:29069225

Monoterpenoids (thymol, carvacrol and S-(+)-linalool) with anesthetic activity in silver catfish (Rhamdia quelen): evaluation of acetylcholinesterase and GABAergic activity.

PubMed

Bianchini, A E; Garlet, Q I; da Cunha, J A; Bandeira, G; Brusque, I C M; Salbego, J; Heinzmann, B M; Baldisserotto, B

2017-10-19

This study evaluated the anesthetic potential of thymol and carvacrol, and their influence on acetylcholinesterase (AChE) activity in the muscle and brain of silver catfish (Rhamdia quelen). The AChE activity of S-(+)-linalool was also evaluated. We subsequently assessed the effects of thymol and S-(+)-linalool on the GABAergic system. Fish were exposed to thymol and carvacrol (25, 50, 75, and 100 mg/L) to evaluate time for anesthesia and recovery. Both compounds induced sedation at 25 mg/L and anesthesia with 50-100 mg/L. However, fish exposed to carvacrol presented strong muscle contractions and mortality. AChE activity was increased in the brain of fish at 50 mg/L carvacrol and 100 mg/L thymol, and decreased in the muscle at 100 mg/L carvacrol. S-(+)-linalool did not alter AChE activity. Anesthesia with thymol was reversed by exposure to picrotoxin (GABAA antagonist), similar to the positive control propofol, but was not reversed by flumazenil (antagonist of benzodiazepine binding site), as observed for the positive control diazepam. Picrotoxin did not reverse the effect of S-(+)-linalool. Thymol exposure at 50 mg/L is more suitable than carvacrol for anesthesia in silver catfish, because this concentration did not cause any mortality or interference with AChE activity. Thymol interacted with GABAA receptors, but not with the GABAA/benzodiazepine site. In contrast, S-(+)-linalool did not act in GABAA receptors in silver catfish.

Practical use of the raw electroencephalogram waveform during general anesthesia: the art and science.

PubMed

Bennett, Cambell; Voss, Logan J; Barnard, John P M; Sleigh, James W

2009-08-01

Quantitative electroencephalogram (qEEG) monitors are often used to estimate depth of anesthesia and intraoperative recall during general anesthesia. As with any monitor, the processed numerical output is often misleading and has to be interpreted within a clinical context. For the safe clinical use of these monitors, a clear mental picture of the expected raw electroencephalogram (EEG) patterns, as well as a knowledge of the common EEG artifacts, is absolutely necessary. This has provided the motivation to write this tutorial. We describe, and give examples of, the typical EEG features of adequate general anesthesia, effects of noxious stimulation, and adjunctive drugs. Artifacts are commonly encountered and may be classified as arising from outside the head, from the head but outside the brain (commonly frontal electromyogram), or from within the brain (atypical or pathologic). We include real examples of clinical problem-solving processes. In particular, it is important to realize that an artifactually high qEEG index is relatively common and may result in dangerous anesthetic drug overdose. The anesthesiologist must be certain that the qEEG number is consistent with the apparent state of the patient, the doses of various anesthetic drugs, and the degree of surgical stimulation, and that the qEEG number is consistent with the appearance of the raw EEG signal. Any discrepancy must be a stimulus for the immediate critical examination of the patient's state using all the available information rather than reactive therapy to "treat" a number.

Inflammatory Profile of Awake Function-Controlled Craniotomy and Craniotomy under General Anesthesia

PubMed Central

Klimek, Markus; Hol, Jaap W.; Wens, Stephan; Heijmans-Antonissen, Claudia; Niehof, Sjoerd; Vincent, Arnaud J.; Klein, Jan; Zijlstra, Freek J.

2009-01-01

Background. Surgical stress triggers an inflammatory response and releases mediators into human plasma such as interleukins (ILs). Awake craniotomy and craniotomy performed under general anesthesia may be associated with different levels of stress. Our aim was to investigate whether those procedures cause different inflammatory responses. Methods. Twenty patients undergoing craniotomy under general anesthesia and 20 patients undergoing awake function-controlled craniotomy were included in this prospective, observational, two-armed study. Circulating levels of IL-6, IL-8, and IL-10 were determined pre-, peri-, and postoperatively in both patient groups. VAS scores for pain, anxiety, and stress were taken at four moments pre- and postoperatively to evaluate physical pain and mental duress. Results. Plasma IL-6 level significantly increased with time similarly in both groups. No significant plasma IL-8 and IL-10 change was observed in both experimental groups. The VAS pain score was significantly lower in the awake group compared to the anesthesia group at 12 hours postoperative. Postoperative anxiety and stress declined similarly in both groups. Conclusion. This study suggests that awake function-controlled craniotomy does not cause a significantly different inflammatory response than craniotomy performed under general anesthesia. It is also likely that function-controlled craniotomy does not cause a greater emotional challenge than tumor resection under general anesthesia. PMID:19536349

Potential Adverse Effects of Prolonged Sevoflurane Exposure on Developing Monkey Brain: From Abnormal Lipid Metabolism to Neuronal Damage.

PubMed

Liu, Fang; Rainosek, Shuo W; Frisch-Daiello, Jessica L; Patterson, Tucker A; Paule, Merle G; Slikker, William; Wang, Cheng; Han, Xianlin

2015-10-01

Sevoflurane is a volatile anesthetic that has been widely used in general anesthesia, yet its safety in pediatric use is a public concern. This study sought to evaluate whether prolonged exposure of infant monkeys to a clinically relevant concentration of sevoflurane is associated with any adverse effects on the developing brain. Infant monkeys were exposed to 2.5% sevoflurane for 9 h, and frontal cortical tissues were harvested for DNA microarray, lipidomics, Luminex protein, and histological assays. DNA microarray analysis showed that sevoflurane exposure resulted in a broad identification of differentially expressed genes (DEGs) in the monkey brain. In general, these genes were associated with nervous system development, function, and neural cell viability. Notably, a number of DEGs were closely related to lipid metabolism. Lipidomic analysis demonstrated that critical lipid components, (eg, phosphatidylethanolamine, phosphatidylserine, and phosphatidylglycerol) were significantly downregulated by prolonged exposure of sevoflurane. Luminex protein analysis indicated abnormal levels of cytokines in sevoflurane-exposed brains. Consistently, Fluoro-Jade C staining revealed more degenerating neurons after sevoflurane exposure. These data demonstrate that a clinically relevant concentration of sevoflurane (2.5%) is capable of inducing and maintaining an effective surgical plane of anesthesia in the developing nonhuman primate and that a prolonged exposure of 9 h resulted in profound changes in gene expression, cytokine levels, lipid metabolism, and subsequently, neuronal damage. Generally, sevoflurane-induced neuronal damage was also associated with changes in lipid content, composition, or both; and specific lipid changes could provide insights into the molecular mechanism(s) underlying anesthetic-induced neurotoxicity and may be sensitive biomarkers for the early detection of anesthetic-induced neuronal damage. Published by Oxford University Press on behalf of the Society of Toxicology 2015. This work is written by a US Government employee and is in the public domain in the US.

Regional entropy of functional imaging signals varies differently in sensory and cognitive systems during propofol-modulated loss and return of behavioral responsiveness.

PubMed

Liu, Xiaolin; Lauer, Kathryn K; Ward, B Douglas; Roberts, Christopher J; Liu, Suyan; Gollapudy, Suneeta; Rohloff, Robert; Gross, William; Xu, Zhan; Chen, Shanshan; Wang, Lubin; Yang, Zheng; Li, Shi-Jiang; Binder, Jeffrey R; Hudetz, Anthony G

2018-05-08

The level and richness of consciousness depend on information integration in the brain. Altered interregional functional interactions may indicate disrupted information integration during anesthetic-induced unconsciousness. How anesthetics modulate the amount of information in various brain regions has received less attention. Here, we propose a novel approach to quantify regional information content in the brain by the entropy of the principal components of regional blood oxygen-dependent imaging signals during graded propofol sedation. Fifteen healthy individuals underwent resting-state scans in wakeful baseline, light sedation (conscious), deep sedation (unconscious), and recovery (conscious). Light sedation characterized by lethargic behavioral responses was associated with global reduction of entropy in the brain. Deep sedation with completely suppressed overt responsiveness was associated with further reductions of entropy in sensory (primary and higher sensory plus orbital prefrontal cortices) but not high-order cognitive (dorsal and medial prefrontal, cingulate, parietotemporal cortices and hippocampal areas) systems. Upon recovery of responsiveness, entropy was restored in the sensory but not in high-order cognitive systems. These findings provide novel evidence for a reduction of information content of the brain as a potential systems-level mechanism of reduced consciousness during propofol anesthesia. The differential changes of entropy in the sensory and high-order cognitive systems associated with losing and regaining overt responsiveness are consistent with the notion of "disconnected consciousness", in which a complete sensory-motor disconnection from the environment occurs with preserved internal mentation.

Activity of respiratory system during laser irradiation of brain structures

NASA Astrophysics Data System (ADS)

Merkulova, N. A.; Sergeyeva, L. I.

1984-06-01

The performance of one of the principal links of the respiratory system, the respiratory center, was studied as a function of the exposure of the medulla oblongata and the sensomotor zone of the cerebral hemisphere cortex to low level laser irradiation in the red wavelength of the spectrum. Experiments were done on white rats under barbital anesthesia. Under such conditions a substantial effect was observed on the activity of the respiratory center. Laser light may display activating or inhibitory influences, in some cases the bilateral symmetry of the activity of the respiratory center is affected indicating deep changes in the integrative mechanism of the functioning of the right and left sides of the hemispheres. The laser beam effect depends on many factors: specific light properties, duration of the exposure, repetition of exposures, initial functional state of the CNS, etc.

Surgery plus anesthesia induces loss of attention in mice

PubMed Central

Ren, Quan; Peng, Mian; Dong, Yuanlin; Zhang, Yiying; Chen, Ming; Yin, Ning; Marcantonio, Edward R.; Xie, Zhongcong

2015-01-01

There is a need to develop animal models to study postoperative delirium. Inattention is one of the symptoms of delirium. Increases in the levels of α-synuclein and S100β have been reported to be associated with delirium. Therefore, we set out to determine the effects of surgery plus general anesthesia on the behavioral changes (including loss of attention) in mice and on the levels of α-synuclein and S100β in the brain tissues of these mice. C57BL/6J mice (2- to 8-months-old) had a simple laparotomy plus isoflurane anesthesia. The behavioral changes, including attention level and the speed of movements, were determined 12, 24, and 48 h after the surgery plus anesthesia in the mice. The levels of α-synuclein and S100β in the cortex of these mice following the surgery plus anesthesia were determined by Western blot analysis. We found that there was a loss of attention at 24, but not 12 or 48 h following the surgery plus anesthesia (49% ± 5 vs. 33% ± 2.9, P = 0.011, N = 12) in the mice without significantly affecting the speed of their movements. There were increases in the levels of total α-synuclein (139% ± 33.5 vs. 100% ± 13.7, P = 0.037, N = 6) and S100β (142% ± 7.7 vs. 100% ± 6, P = 0.002, N = 6) in the cortex of the mice 12 h following the surgery plus anesthesia. These findings suggested that the surgery plus isoflurane anesthesia might induce behavioral and biochemical/cellular changes associated with delirium. We could use the surgery plus anesthesia in mice to develop an animal model to study postoperative delirium. PMID:26441522

Surgery plus anesthesia induces loss of attention in mice.

PubMed

Ren, Quan; Peng, Mian; Dong, Yuanlin; Zhang, Yiying; Chen, Ming; Yin, Ning; Marcantonio, Edward R; Xie, Zhongcong

2015-01-01

There is a need to develop animal models to study postoperative delirium. Inattention is one of the symptoms of delirium. Increases in the levels of α-synuclein and S100β have been reported to be associated with delirium. Therefore, we set out to determine the effects of surgery plus general anesthesia on the behavioral changes (including loss of attention) in mice and on the levels of α-synuclein and S100β in the brain tissues of these mice. C57BL/6J mice (2- to 8-months-old) had a simple laparotomy plus isoflurane anesthesia. The behavioral changes, including attention level and the speed of movements, were determined 12, 24, and 48 h after the surgery plus anesthesia in the mice. The levels of α-synuclein and S100β in the cortex of these mice following the surgery plus anesthesia were determined by Western blot analysis. We found that there was a loss of attention at 24, but not 12 or 48 h following the surgery plus anesthesia (49% ± 5 vs. 33% ± 2.9, P = 0.011, N = 12) in the mice without significantly affecting the speed of their movements. There were increases in the levels of total α-synuclein (139% ± 33.5 vs. 100% ± 13.7, P = 0.037, N = 6) and S100β (142% ± 7.7 vs. 100% ± 6, P = 0.002, N = 6) in the cortex of the mice 12 h following the surgery plus anesthesia. These findings suggested that the surgery plus isoflurane anesthesia might induce behavioral and biochemical/cellular changes associated with delirium. We could use the surgery plus anesthesia in mice to develop an animal model to study postoperative delirium.

Physostigmine and Methylphenidate Induce Distinct Arousal States During Isoflurane General Anesthesia in Rats.

PubMed

Kenny, Jonathan D; Chemali, Jessica J; Cotten, Joseph F; Van Dort, Christa J; Kim, Seong-Eun; Ba, Demba; Taylor, Norman E; Brown, Emery N; Solt, Ken

2016-11-01

Although emergence from general anesthesia is clinically treated as a passive process driven by the pharmacokinetics of drug clearance, agents that hasten recovery from general anesthesia may be useful for treating delayed emergence, emergence delirium, and postoperative cognitive dysfunction. Activation of central monoaminergic neurotransmission with methylphenidate has been shown to induce reanimation (active emergence) from general anesthesia. Cholinergic neurons in the brainstem and basal forebrain are also known to promote arousal. The objective of this study was to test the hypothesis that physostigmine, a centrally acting cholinesterase inhibitor, induces reanimation from isoflurane anesthesia in adult rats. The dose-dependent effects of physostigmine on time to emergence from a standardized isoflurane general anesthetic were tested. It was then determined whether physostigmine restores righting during continuous isoflurane anesthesia. In a separate group of rats with implanted extradural electrodes, physostigmine was administered during continuous inhalation of 1.0% isoflurane, and the electroencephalogram changes were recorded. Finally, 2.0% isoflurane was used to induce burst suppression, and the effects of physostigmine and methylphenidate on burst suppression probability (BSP) were tested. Physostigmine delayed time to emergence from isoflurane anesthesia at doses ≥0.2 mg/kg (n = 9). During continuous isoflurane anesthesia (0.9% ± 0.1%), physostigmine did not restore righting (n = 9). Blocking the peripheral side effects of physostigmine with the coadministration of glycopyrrolate (a muscarinic antagonist that does not cross the blood-brain barrier) produced similar results (n = 9 each). However, during inhalation of 1.0% isoflurane, physostigmine shifted peak electroencephalogram power from δ (<4 Hz) to θ (4-8 Hz) in 6 of 6 rats. During continuous 2.0% isoflurane anesthesia, physostigmine induced large, statistically significant decreases in BSP in 6 of 6 rats, whereas methylphenidate did not. Unlike methylphenidate, physostigmine does not accelerate time to emergence from isoflurane anesthesia and does not restore righting during continuous isoflurane anesthesia. However, physostigmine consistently decreases BSP during deep isoflurane anesthesia, whereas methylphenidate does not. These findings suggest that activation of cholinergic neurotransmission during isoflurane anesthesia produces arousal states that are distinct from those induced by monoaminergic activation.

Relationship between Child and Parental Dental Anxiety with Child's Psychological Functioning and Behavior during the Administration of Local Anesthesia.

PubMed

Boka, Vasiliki; Arapostathis, Konstantinos; Kotsanos, Nikolaos; Karagiannis, Vassilis; van Loveren, Cor; Veerkamp, Jaap

2016-01-01

The aims of this study were to determine: 1) the relationship between children's psychological functioning, dental anxiety and cooperative behavior before and during local anesthesia, 2) the relationship of parental dental anxiety with all the above child characteristics. There was a convenient sample of 100 children (4-12 years). Child dental anxiety and psychological functioning were measured using the "Children's Fear Survey Schedule" (CFSS-DS) and the "Strengths and Difficulties Questionnaire" (SDQ) respectively. Parental dental anxiety was measured using the "Modified Dental Anxiety Scale" (MDAS). All questionnaires were completed by parents. Before and during local anesthesia, the child behavior was scored by one experienced examiner, using the Venham scale. Non-parametric tests and correlations (Mann-Whitney, Spearman's rho) were used for the analysis. The mean SDQ score was 10±5.6 for boys (n=60) and 8.3±4.8 for girls (n=40) (p=0.038), but there was no correlation with children's age. The mean CFSS-DS score was 33.1±11.86 and there was no correlation with age or gender. Children with higher levels in the pro-social subscale of the SDQ had significantly less anxiety and better behavior before local anesthesia. Higher mean CFSS-DS scores were significantly associated with uncooperative behavior during local anesthesia (p=0.04). There was no correlation between parents' and their children's dental anxiety, psychological functioning and behavior. 46% of the children had previous dental experience in the last 6 months. As time since the last dental treatment increased, an improvement was found in children's behavior during local anesthesia. Child psychological functioning was related to dental anxiety and behavior during dental appointment involving local anesthesia.

[Personal computer-based computer monitoring system of the anesthesiologist (2-year experience in development and use)].

PubMed

Buniatian, A A; Sablin, I N; Flerov, E V; Mierbekov, E M; Broĭtman, O G; Shevchenko, V V; Shitikov, I I

1995-01-01

Creation of computer monitoring systems (CMS) for operating rooms is one of the most important spheres of personal computer employment in anesthesiology. The authors developed a PC RS/AT-based CMS and effectively used it for more than 2 years. This system permits comprehensive monitoring in cardiosurgical operations by real time processing the values of arterial and central venous pressure, pressure in the pulmonary artery, bioelectrical activity of the brain, and two temperature values. Use of this CMS helped appreciably improve patients' safety during surgery. The possibility to assess brain function by computer monitoring the EEF simultaneously with central hemodynamics and body temperature permit the anesthesiologist to objectively assess the depth of anesthesia and to diagnose cerebral hypoxia. Automated anesthesiological chart issued by the CMS after surgery reliably reflects the patient's status and the measures taken by the anesthesiologist.

Supplemental Interscalene Blockade to General Anesthesia for Shoulder Arthroscopy: Effects on Fast Track Capability, Analgesic Quality, and Lung Function.

PubMed

Zoremba, Martin; Kratz, Thomas; Dette, Frank; Wulf, Hinnerk; Steinfeldt, Thorsten; Wiesmann, Thomas

2015-01-01

After shoulder surgery performed in patients with interscalene nerve block (without general anesthesia), fast track capability and postoperative pain management in the PACU are improved compared with general anesthesia alone. However, it is not known if these evidence-based benefits still exist when the interscalene block is combined with general anesthesia. We retrospectively analyzed a prospective cohort data set of 159 patients undergoing shoulder arthroscopy with general anesthesia alone (n = 60) or combined with an interscalene nerve block catheter (n = 99) for fast track capability time. Moreover, comparisons were made for VAS scores, analgesic consumption in the PACU, pain management, and lung function measurements. The groups did not differ in mean time to fast track capability (22 versus 22 min). Opioid consumption in PACU was significantly less in the interscalene group, who had significantly better VAS scores during PACU stay. Patients receiving interscalene blockade had a significantly impaired lung function postoperatively, although this did not affect postoperative recovery and had no impact on PACU times. The addition of interscalene block to general anesthesia for shoulder arthroscopy did not enhance fast track capability. Pain management and VAS scores were improved in the interscalene nerve block group.

Measurement of pediatric regional cerebral blood flow from 6 months to 15 years of age in a clinical population.

PubMed

Carsin-Vu, Aline; Corouge, Isabelle; Commowick, Olivier; Bouzillé, Guillaume; Barillot, Christian; Ferré, Jean-Christophe; Proisy, Maia

2018-04-01

To investigate changes in cerebral blood flow (CBF) in gray matter (GM) between 6 months and 15 years of age and to provide CBF values for the brain, GM, white matter (WM), hemispheres and lobes. Between 2013 and 2016, we retrospectively included all clinical MRI examinations with arterial spin labeling (ASL). We excluded subjects with a condition potentially affecting brain perfusion. For each subject, mean values of CBF in the brain, GM, WM, hemispheres and lobes were calculated. GM CBF was fitted using linear, quadratic and cubic polynomial regression against age. Regression models were compared with Akaike's information criterion (AIC), and Likelihood Ratio tests. 84 children were included (44 females/40 males). Mean CBF values were 64.2 ± 13.8 mL/100 g/min in GM, and 29.3 ± 10.0 mL/100 g/min in WM. The best-fit model of brain perfusion was the cubic polynomial function (AIC = 672.7, versus respectively AIC = 673.9 and AIC = 674.1 with the linear negative function and the quadratic polynomial function). A statistically significant difference between the tested models demonstrating the superiority of the quadratic (p = 0.18) or cubic polynomial model (p = 0.06), over the negative linear regression model was not found. No effect of general anesthesia (p = 0.34) or of gender (p = 0.16) was found. we provided values for ASL CBF in the brain, GM, WM, hemispheres, and lobes over a wide pediatric age range, approximately showing inverted U-shaped changes in GM perfusion over the course of childhood. Copyright © 2018 Elsevier B.V. All rights reserved.

Imaging in the newborn: infant immobilizer obviates the need for anesthesia.

PubMed

Golan, Agneta; Marco, Rina; Raz, Hagit; Shany, Eilon

2011-11-01

Neonatal cerebral imaging is a sensitive technique for evaluating brain injury in the neonatal period. When performing computed tomography or magnetic resonance imaging, sedation is needed to prevent motion artifacts. However, general anesthesia in neonates carries significant risks and requires a complex logistic approach that often limits the use of these modalities. The development of infant immobilizers now enables imaging without general anesthesia and significantly increases clinical and research investigational opportunities. To assess the efficacy of the infant immobilizer instead of general anesthesia for infants undergoing imaging. The study group comprised all infants born over a 1 year period at Soroka University Medical Center who required imaging such as MRI, CT or bone scans. A MedVac Vacuum Splint infant immobilizer was used in all infants to prevent motion during imaging. The success rate of a single scan and the need for general anesthesia were assessed. Forty infants were examined during 1 year. The studies included 15 CT scans, 25 MRIs and 1 bone scan. The infants' gestational age at birth was 27-40 weeks and the examinations were performed at ages ranging from delivery to 6 months old. All imaging was successful and none of the infants required general anesthesia. An infant immobilizer should be used for imaging of newborns. Since this method carries a low risk and has a high success rate, general anesthesia in newborns is justified only when this non-invasive procedure fails.

Consciousness and Complexity during Unresponsiveness Induced by Propofol, Xenon, and Ketamine.

PubMed

Sarasso, Simone; Boly, Melanie; Napolitani, Martino; Gosseries, Olivia; Charland-Verville, Vanessa; Casarotto, Silvia; Rosanova, Mario; Casali, Adenauer Girardi; Brichant, Jean-Francois; Boveroux, Pierre; Rex, Steffen; Tononi, Giulio; Laureys, Steven; Massimini, Marcello

2015-12-07

A common endpoint of general anesthetics is behavioral unresponsiveness, which is commonly associated with loss of consciousness. However, subjects can become disconnected from the environment while still having conscious experiences, as demonstrated by sleep states associated with dreaming. Among anesthetics, ketamine is remarkable in that it induces profound unresponsiveness, but subjects often report "ketamine dreams" upon emergence from anesthesia. Here, we aimed at assessing consciousness during anesthesia with propofol, xenon, and ketamine, independent of behavioral responsiveness. To do so, in 18 healthy volunteers, we measured the complexity of the cortical response to transcranial magnetic stimulation (TMS)--an approach that has proven helpful in assessing objectively the level of consciousness irrespective of sensory processing and motor responses. In addition, upon emergence from anesthesia, we collected reports about conscious experiences during unresponsiveness. Both frontal and parietal TMS elicited a low-amplitude electroencephalographic (EEG) slow wave corresponding to a local pattern of cortical activation with low complexity during propofol anesthesia, a high-amplitude EEG slow wave corresponding to a global, stereotypical pattern of cortical activation with low complexity during xenon anesthesia, and a wakefulness-like, complex spatiotemporal activation pattern during ketamine anesthesia. Crucially, participants reported no conscious experience after emergence from propofol and xenon anesthesia, whereas after ketamine they reported long, vivid dreams unrelated to the external environment. These results are relevant because they suggest that brain complexity may be sensitive to the presence of disconnected consciousness in subjects who are considered unconscious based on behavioral responses. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Utility of Local Anesthesia for Neurosurgical Interventions in a Low-Resource Setting: A Case Series.

PubMed

Eaton, Jessica; Hanif, Asma Bilal; Mzumara, Suzgisam; Charles, Anthony

2018-05-01

Trauma is a major contributor to global morbidity and mortality, and injury to the central nervous system is the most common cause of death in these patients. While the provision of surgical services is being recognized as essential to global public health efforts, specialty areas such as neurosurgery remain overlooked. This is a retrospective case review of patients with operable lesions, such as extra-axial hematomas and unstable depressed skull fractures that underwent neurosurgical interventions under local anesthesia. A total of 13 patients underwent neurosurgical intervention under local anesthesia. Two and three patients with burr hole decompression of epidural and subdural hematomas, respectively; seven patients had elevation of depressed skull fractures and lastly one patient had an aspiration of a brain abscess. All patients survived with and without residual neurological deficits. Access to resources and staff required to deliver general anesthesia is challenging in resource-poor settings. We have therefore begun performing emergent interventions under local anesthesia, with or without conscious sedation. While some patients had some minor residual weakness after the procedure, the degree of neurological deficit was improved from that observed before the procedure in all patients.

The 8-item Short-Form Health Survey and the physical comfort composite score of the quality of recovery 40-item scale provide the most responsive assessments of pain, physical function, and mental function during the first 4 days after ambulatory knee surgery with regional anesthesia.

PubMed

Bost, James E; Williams, Brian A; Bottegal, Matthew T; Dang, Qianyu; Rubio, Doris M

2007-12-01

We evaluated the validity and responsiveness of three instruments: the numeric rating scale (NRS) pain score, the 8-item Short-Form Health Survey (SF-8), and the 40-item Quality of Recovery from Anesthesia (QoR) Survey in 154 outpatients undergoing anterior cruciate ligament reconstruction (ACLR). The objective was to provide a robust psychometric basis for outcome survey selection for surgical outpatients undergoing regional anesthesia without general anesthesia. Patients undergoing ACLR with a standardized spinal anesthesia plan were randomized to receive a perineural catheter with either placebo injection-infusion, or injection-infusion with levobupivacaine. Patients completed the NRS, SF-8, and QoR instruments for four postoperative days to evaluate pain, physical function, and mental function. Regarding pain, neither the NRS nor the QoR offered advantages over the SF-8. Regarding physical function, the QoR physical independence composite offered no advantage over the SF-8 physical component summary. The QoR physical comfort composite assessed short-term changes in treatment-related side effects, and thus provided information not covered by the SF-8. Regarding mental function, the SF-8 mental component summary and QoR emotional state composite showed little change over the four days, although the latter measure showed higher responsiveness to change. For ACLR outpatients receiving regional anesthesia, the SF-8 is sufficient to assess postoperative pain and physical function. Adding the QoR physical comfort composite will help assess short-term side effects.

Pretreatment with minocycline restores neurogenesis in the subventricular zone and subgranular zone of the hippocampus after ketamine exposure in neonatal rats.

PubMed

Lu, Yang; Giri, P K; Lei, Shan; Zheng, Juan; Li, Weisong; Wang, Ning; Chen, Xinlin; Lu, Haixia; Zuo, Zhiyi; Liu, Yong; Zhang, Pengbo

2017-06-03

Ketamine is commonly used for anesthesia in pediatric patients. Recent studies indicated that ketamine exposure in the developing brain can induce neuroapoptosis and disturb normal neurogenesis, which will result in long-lasting cognitive impairment. Minocycline exerts neuroprotection against a wide range of toxic insults in neurodegenerative disease models. In the present study, we investigated whether the disturbed neurogenesis and behavioral deficits after ketamine neonatal exposure could be alleviated by minocycline. Postnatal day (PND)7 Sprague-Dawley rat pups randomly received either normal saline, ketamine, or minocycline 30min prior to ketamine administration, respectively. The rats were decapitated at PND14 for the detection of neurogenesis in the subventricular zone (SVZ) and subgranular zone (SGZ) of the hippocampus by immunostaining. The protein expression of p-Akt, p-GSK-3β in the SVZ and SGZ at 12h after anesthesia, PND10 and PND14 were assessed by western blotting analysis. At PND 42-47, spatial learning and memory abilities were measured by the Morris water maze in all groups. Our data showed that ketamine exposure in neonatal rats resulted in neurogenetic damage and persistent cognitive deficits, and that pretreatment with minocycline eliminated the brain development damage and improved the behavioral function in adult rats. Moreover, the protection of minocycline is associated with the PI3K/Akt signaling pathway. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Experience-dependent modulation of feedback integration during singing: role of the right anterior insula.

PubMed

Kleber, Boris; Zeitouni, Anthony G; Friberg, Anders; Zatorre, Robert J

2013-04-03

Somatosensation plays an important role in the motor control of vocal functions, yet its neural correlate and relation to vocal learning is not well understood. We used fMRI in 17 trained singers and 12 nonsingers to study the effects of vocal-fold anesthesia on the vocal-motor singing network as a function of singing expertise. Tasks required participants to sing musical target intervals under normal conditions and after anesthesia. At the behavioral level, anesthesia altered pitch accuracy in both groups, but singers were less affected than nonsingers, indicating an experience-dependent effect of the intervention. At the neural level, this difference was accompanied by distinct patterns of decreased activation in singers (cortical and subcortical sensory and motor areas) and nonsingers (subcortical motor areas only) respectively, suggesting that anesthesia affected the higher-level voluntary (explicit) motor and sensorimotor integration network more in experienced singers, and the lower-level (implicit) subcortical motor loops in nonsingers. The right anterior insular cortex (AIC) was identified as the principal area dissociating the effect of expertise as a function of anesthesia by three separate sources of evidence. First, it responded differently to anesthesia in singers (decreased activation) and nonsingers (increased activation). Second, functional connectivity between AIC and bilateral A1, M1, and S1 was reduced in singers but augmented in nonsingers. Third, increased BOLD activity in right AIC in singers was correlated with larger pitch deviation under anesthesia. We conclude that the right AIC and sensory-motor areas play a role in experience-dependent modulation of feedback integration for vocal motor control during singing.

Depletion of serotonin synthesis with p-CPA pretreatment alters EEG in urethane anesthetized rats under whole body hyperthermia.

PubMed

Sinha, Rakesh Kumar; Aggarwal, Yogender

2007-01-01

Serotonin is believed as an important factor in brain function. The role of serotonin in cerebral psycho-patho-physiology has already been well established. However, the function of serotonin antagonist in anesthetized subjects under hyperthermia has not been studied properly. Experiments were performed in three groups of urethane-anesthetized rats, such as: (i) control group, (ii) whole body hyperthermia group and (iii) p-CPA (para-Chlorophenylalanine) pretreated hyperthermia group. Hyperthermia was produced by subjecting the rats to high ambient temperature of 38 +/- 1 degrees C (relative humidity 45-50%). Each group was divided for EEG (electroencephalogram) study and for determination of edematous swelling in the brain. Urethane anesthetized rats under hyperthermia show highly significant reduction in their survival time. The body temperature recorded during the hyperthermia was observed with significant and linear rise with marked increase in brain water content, which was analyzed just after the death of the subjects. The results of the electroencephalographic study in urethane-anesthetized rats recorded before death indicate that brain function varies in systematic manner during hyperthermia as sequential changes in EEG patterns were observed. However, a serotonin antagonist, p-CPA pretreatment increases the survival time with significant reduction in edematous swelling in brain but it does not affect the relationship between the core body temperature and the brain cortical potentials as observed in urethane anesthetized subjects exposed to whole body hyperthermia. The core body temperature in p-CPA pretreated rats show non-linear relationship with respect to the exposure time as it was observed in drug untreated subjects. The findings of the present study indicate that although pretreatment of p-CPA in rats has a marked correlation between the extravasations of the blood-brain barrier under hyperthermia but shows minimum effect on the EEG in a model of hyperthermia under irreversible anesthesia.

[Crisis management in pediatric anesthesia].

PubMed

Takeuchi, Mamoru; Otsuka, Yoji; Taga, Naoyuki; Sato, Yuki; Iwai, Hidetaka; Okada, Osamu

2009-05-01

We describe the risk management of pediatric anesthesia. The most important risk management of pediatric anesthesia is airway and temperature management. Neonates and infants easily become hypoxic due to their insufficient functional residual capacity. Therefore airway management is most important not only during induction of anesthesia but also during maintenance of anesthesia and extubation. The management of patients' temperature, including control of room temperature should be taken into consideration. In addition, careful attention should be paid not to introduce air bubbles in any lines, especially in patients with congenital heart diseases.

Successful deep brain stimulation surgery with intraoperative magnetic resonance imaging on a difficult neuroacanthocytosis case: case report.

PubMed

Lim, Thien Thien; Fernandez, Hubert H; Cooper, Scott; Wilson, Kathryn Mary K; Machado, Andre G

2013-07-01

Chorea acanthocytosis is a progressive hereditary neurodegenerative disorder characterized by hyperkinetic movements, seizures, and acanthocytosis in the absence of any lipid abnormality. Medical treatment is typically limited and disappointing. We report on a 32-year-old patient with chorea acanthocytosis with a failed attempt at awake deep brain stimulation (DBS) surgery due to intraoperative seizures and postoperative intracranial hematoma. He then underwent a second DBS operation, but under general anesthesia and with intraoperative magnetic resonance imaging guidance. Marked improvement in his dystonia, chorea, and overall quality of life was noted 2 and 8 months postoperatively. DBS surgery of the bilateral globus pallidus pars interna may be useful in controlling the hyperkinetic movements in neuroacanthocytosis. Because of the high propensity for seizures in this disorder, DBS performed under general anesthesia, with intraoperative magnetic resonance imaging guidance, may allow successful implantation while maintaining accurate target localization.

Recovery of dynamic balance after general anesthesia with sevoflurane in short-duration oral surgery.

PubMed

Fujisawa, Toshiaki; Miyamoto, Eriko; Takuma, Shigeru; Shibuya, Makiko; Kurozumi, Akihiro; Kimura, Yukifumi; Kamekura, Nobuhito; Fukushima, Kazuaki

2009-01-01

Recovery of dynamic balance, involving adjustment of the center of gravity, is essential for safe discharge on foot after ambulatory anesthesia. The purpose of this study was to assess the recovery of dynamic balance after general anesthesia with sevoflurane, using two computerized dynamic posturographies. Nine hospitalized patients undergoing oral surgery of less than 2 h duration under general anesthesia (air-oxygensevoflurane) were studied. A dynamic balance test, assessing the ability of postural control against unpredictable perturbation stimuli (Stability System; Biodex Medical), a walking analysis test using sheets with foot pressure sensors (Walk Way-MG1000; Anima), and two simple psychomotor function tests were performed before anesthesia (baseline), and 150 and 210 min after the emergence from anesthesia. Only the double-stance phase in the walking analysis test showed a significant difference between baseline and results at 150 min. None of the other variables showed any differences among results at baseline and at 150 and 210 min. The recovery times for dynamic balance and psychomotor function seem to be within 150 min after emergence from general anesthesia with sevoflurane in patients undergoing oral surgery of less than 2-h duration.

Age-dependent postoperative cognitive impairment and Alzheimer-related neuropathology in mice

NASA Astrophysics Data System (ADS)

Xu, Zhipeng; Dong, Yuanlin; Wang, Hui; Culley, Deborah J.; Marcantonio, Edward R.; Crosby, Gregory; Tanzi, Rudolph E.; Zhang, Yiying; Xie, Zhongcong

2014-01-01

Post-operative cognitive dysfunction (POCD) is associated with increased cost of care, morbidity, and mortality. However, its pathogenesis remains largely to be determined. Specifically, it is unknown why elderly patients are more likely to develop POCD and whether POCD is dependent on general anesthesia. We therefore set out to investigate the effects of peripheral surgery on the cognition and Alzheimer-related neuropathology in mice with different ages. Abdominal surgery under local anesthesia was established in the mice. The surgery induced post-operative elevation in brain β-amyloid (Aβ) levels and cognitive impairment in the 18 month-old wild-type and 9 month-old Alzheimer's disease transgenic mice, but not the 9 month-old wild-type mice. The Aβ accumulation likely resulted from elevation of beta-site amyloid precursor protein cleaving enzyme and phosphorylated eukaryotic translation initiation factor 2α. γ-Secretase inhibitor compound E ameliorated the surgery-induced brain Aβ accumulation and cognitive impairment in the 18 month-old mice. These data suggested that the peripheral surgery was able to induce cognitive impairment independent of general anesthesia, and that the combination of peripheral surgery with aging- or Alzheimer gene mutation-associated Aβ accumulation was needed for the POCD to occur. These findings would likely promote more research to investigate the pathogenesis of POCD.

Examiner's finger-mounted near-infrared spectroscopy is feasible to analyze cerebral and skeletal muscle oxygenation in conscious Chihuahuas.

PubMed

Hiwatashi, Keisuke; Doi, Kimiaki; Mizuno, Risuke; Yokosuka, Makoto

2017-02-01

To measure regional saturation of oxygen ( rSO 2 ) of hemoglobin and total hemoglobin index (HbI) in the brain (through the molera of the head) and skeletal muscle (musculus gracilis) of conscious Chihuahua dogs using an examiner’s finger-mounted near-infrared spectroscopy (NIRS) device, Toccare, we investigated brain and skeletal muscle NIRS in 48 Chihuahuas without severe disease. To measure rSO 2 and total HbI, a Toccare probe was placed on the molera of the head and musculus gracilis of each dog for real-time recording. Stable NIRS values were obtained within 10 s. We also examined the effect of anesthesia on rSO 2 and total HbI of a Chihuahua. Cerebral rSO 2 values ( 59 % ± 7 % ) were significantly lower than those obtained at femoral regions ( 67 % ± 6 % ), whereas total HbI values in the brain ( 0.38 ± 0.09 ) were significantly higher than those of the musculus gracilis ( 0.20 ± 0.05 ). Sedation with a combination of medetomidine and ketamine decreased cerebral rSO 2 along with a corresponding reduction in heart rate. Sevoflurane anesthesia with 100% O 2 maintained rSO 2 in the brain with a

Caudal thoracic air sac cannulation in zebra finches for isoflurane anesthesia.

PubMed

Nilson, Paige Crystal; Teramitsu, Ikuko; White, Stephanie Ann

2005-04-30

Small songbirds such as the zebra finch are commonly used for studies on the neural mechanisms that underlie vocal learning. For these studies, survival surgeries are often performed that involve animal anesthesia and stereotaxic stabilization for localization of specific brain regions. Here we describe air sac cannulation as a novel method for delivering isoflurane gas to zebra finches for anesthesia during neurosurgery. Advantages of this method include that it leaves the bird's head free for stereotaxic targeting and does not interfere with the beak clamps that are often used to position and stabilize the head. It additionally allows for the use of the inhalant anesthetic, isoflurane, which is an appealing alternative to injectable anesthetics because it provides fast, minimally stressful induction, and low subject and personnel toxicity. The use of isoflurane also prevents overdosing and lengthy postoperative recovery times.

A Prospective Study of Age-dependent Changes in Propofol-induced Electroencephalogram Oscillations in Children.

PubMed

Lee, Johanna M; Akeju, Oluwaseun; Terzakis, Kristina; Pavone, Kara J; Deng, Hao; Houle, Timothy T; Firth, Paul G; Shank, Erik S; Brown, Emery N; Purdon, Patrick L

2017-08-01

In adults, frontal electroencephalogram patterns observed during propofol-induced unconsciousness consist of slow oscillations (0.1 to 1 Hz) and coherent alpha oscillations (8 to 13 Hz). Given that the nervous system undergoes significant changes during development, anesthesia-induced electroencephalogram oscillations in children may differ from those observed in adults. Therefore, we investigated age-related changes in frontal electroencephalogram power spectra and coherence during propofol-induced unconsciousness. We analyzed electroencephalogram data recorded during propofol-induced unconsciousness in patients between 0 and 21 yr of age (n = 97), using multitaper spectral and coherence methods. We characterized power and coherence as a function of age using multiple linear regression analysis and within four age groups: 4 months to 1 yr old (n = 4), greater than 1 to 7 yr old (n = 16), greater than 7 to 14 yr old (n = 30), and greater than 14 to 21 yr old (n = 47). Total electroencephalogram power (0.1 to 40 Hz) peaked at approximately 8 yr old and subsequently declined with increasing age. For patients greater than 1 yr old, the propofol-induced electroencephalogram structure was qualitatively similar regardless of age, featuring slow and coherent alpha oscillations. For patients under 1 yr of age, frontal alpha oscillations were not coherent. Neurodevelopmental processes that occur throughout childhood, including thalamocortical development, may underlie age-dependent changes in electroencephalogram power and coherence during anesthesia. These age-dependent anesthesia-induced electroencephalogram oscillations suggest a more principled approach to monitoring brain states in pediatric patients.

Thermal camera used for the assessment of metabolism and functions of the rat brain

NASA Astrophysics Data System (ADS)

Kastek, Mariusz; Piatkowski, Tadeusz; Polakowski, Henryk; Kaczmarska, Katarzyna; Czernicki, Zbigniew; Koźniewska, Ewa; Przykaza, Lukasz

2014-05-01

Motivation to undertake research on brain surface temperature in clinical practice is based on a strong conviction that the enormous progress in thermal imaging techniques and camera design has a great application potential. Intraoperative imaging of pathological changes and functionally important areas of the brain is not yet fully resolved in neurosurgery and remains a challenge. Extensive knowledge of the complex mechanisms controlling homeostasis (thermodynamic status of an organism being a part of it ) and laws of physics (which are the foundations of thermography), make this method very good and a simple imaging tool in comparison with other modern techniques, such as computed tomography, magnetic resonance imaging and angiography. Measurements of temperature distribution across the brain surface were performed on four rats (Wistar strain) weighing approximately 300 g each. Animals have remained under general anesthesia typically conducted using isoflurane. The brain was unveiled (the dura mater remained untouched) through the skin incision and removal of the bone cranial vault. Cerebrocortical microflow was measured using laser-Doppler flow meter. Arterial blood pressure was also measured in rat femoral artery. From the above data the cerebrovascular resistance index was calculated. Cerebral flow was modified by increasing the CO2 concentration in the inspired air to 5% for the duration of 6 minutes. Another change in cerebral flow was induced by periodic closing of right middle cerebral artery. Artery occlusion was performed by introducing a filament for a period of 15 minutes, then an artery was opened again. Measurements were carried out before, during and after the artery occlusion. Paper presents results and methodology of measurements.

Patient injuries from anesthesia gas delivery equipment: a closed claims update.

PubMed

Mehta, Sonya P; Eisenkraft, James B; Posner, Karen L; Domino, Karen B

2013-10-01

Improvements in anesthesia gas delivery equipment and provider training may increase patient safety. The authors analyzed patient injuries related to gas delivery equipment claims from the American Society of Anesthesiologists Closed Claims Project database over the decades from 1970s to the 2000s. After the Institutional Review Board approval, the authors reviewed the Closed Claims Project database of 9,806 total claims. Inclusion criteria were general anesthesia for surgical or obstetric anesthesia care (n = 6,022). Anesthesia gas delivery equipment was defined as any device used to convey gas to or from (but not involving) the airway management device. Claims related to anesthesia gas delivery equipment were compared between time periods by chi-square test, Fisher exact test, and Mann-Whitney U test. Anesthesia gas delivery claims decreased over the decades (P < 0.001) to 1% of claims in the 2000s. Outcomes in claims from 1990 to 2011 (n = 40) were less severe, with a greater proportion of awareness (n = 9, 23%; P = 0.003) and pneumothorax (n = 7, 18%; P = 0.047). Severe injuries (death/permanent brain damage) occurred in supplemental oxygen supply events outside the operating room, breathing circuit events, or ventilator mishaps. The majority (85%) of claims involved provider error with (n = 7) or without (n = 27) equipment failure. Thirty-five percent of claims were judged as preventable by preanesthesia machine check. Gas delivery equipment claims in the Closed Claims Project database decreased in 1990-2011 compared with earlier decades. Provider error contributed to severe injury, especially with inadequate alarms, improvised oxygen delivery systems, and misdiagnosis or treatment of breathing circuit events.

Influence of serial electrical stimulations of perifornical and posterior hypothalamic orexin-containing neurons on regulation of sleep homeostasis and sleep-wakefulness cycle recovery from experimental comatose state and anesthesia-induced deep sleep.

PubMed

Chijavadze, E; Chkhartishvili, E; Babilodze, M; Maglakelidze, N; Nachkebia, N

2013-11-01

The work was aimed for the ascertainment of following question - whether Orexin-containing neurons of dorsal and lateral hypothalamic, and brain Orexinergic system in general, are those cellular targets which can speed up recovery of disturbed sleep homeostasis and accelerate restoration of sleep-wakefulness cycle phases during some pathological conditions - experimental comatose state and/or deep anesthesia-induced sleep. Study was carried out on white rats. Modeling of experimental comatose state was made by midbrain cytotoxic lesions at intra-collicular level.Animals were under artificial respiration and special care. Different doses of Sodium Ethaminal were used for deep anesthesia. 30 min after comatose state and/or deep anesthesia induced sleep serial electrical stimulations of posterior and/or perifornical hypothalamus were started. Stimulation period lasted for 1 hour with the 5 min intervals between subsequent stimulations applied by turn to the left and right side hypothalamic parts.EEG registration of cortical and hippocampal electrical activity was started immediately after experimental comatose state and deep anesthesia induced sleep and continued continuously during 72 hour. According to obtained new evidences, serial electrical stimulations of posterior and perifornical hypothalamic Orexin-containing neurons significantly accelerate recovery of sleep homeostasis, disturbed because of comatose state and/or deep anesthesia induced sleep. Speed up recovery of sleep homeostasis was manifested in acceleration of coming out from comatose state and deep anesthesia induced sleep and significant early restoration of sleep-wakefulness cycle behavioral states.

Something new about ketamine for pediatric anesthesia?

PubMed

Lois, Fernande; De Kock, Marc

2008-06-01

This review discusses the place of the old anesthetic ketamine in pediatric anesthesia. Despite the availability of modern alternatives, ketamine remains a frequently used drug particularly for anesthesia in high-risk children and for procedures outside the operating room. In adult patients undergoing surgery, a renewed interest in this drug is noted. It is the consequence of recent demonstrations of the following effects. First, ketamine is highly effective against surgery and opiate-induced hyperalgesia. Second, it has original antiproinflammatory properties. In other words, it promotes self-limitation of the inflammatory response that follows surgery. In the pediatric population, these benefits wait to be confirmed. Finally, questions arise about the safety of ketamine anesthesia. Ketamine is a potent proapoptotic drug. In rodents treated during the critical period for central nervous system development, long-term behavioral deficits were noted after an anesthetic dose of ketamine. The exact consequences of these proapoptotic properties on human brain tissue development have to be exactly determined and are still debatable. Ketamine has not yet revealed all its interactions in humans. Recent discoveries indicate interesting properties on the one hand and potentially deleterious effects on the other.

Repeated inhalation of sevoflurane inhibits the information transmission of Purkinje cells and delays motor development via the GABAA receptor ε subunit in neonatal mice.

PubMed

Fang, Hong; Wang, Ze-Hua; Bu, Ying-Jiang; Yuan, Zhi-Jun; Wang, Guo-Qiang; Guo, Yan; Cheng, Xiao-Yun; Qiu, Wen-Jie

2018-01-01

General anesthesia is widely used in pediatric surgery, although the influence of general anesthesia on cerebellar information transmission and motor function is unclear. In the present study, neonatal mice received repeated inhalation of sevoflurane, and electrophysiological alterations in Purkinje cells (PCs) and the development of motor functions were detected. In addition, γ‑aminobutyric acidA receptor ε (GABAA‑R ε) subunit knockout mice were used to investigate the mechanism of action of sevoflurane on cerebellar function. In the neonatal mice, the field potential response of PCs induced by sensory stimulation and the motor function indices were markedly inhibited by sevoflurane, and the inhibitory effect was positively associated with the number of repetitions of anesthesia. In additional the GABAA‑R ε subunit level of PCs was promoted by sevoflurane in a dose‑dependent manner, and the inhibitory effects of sevoflurane on PC field potential response and motor function were alleviated in GABAA‑R ε subunit knockout mice. The GABAA‑R ε subunit was activated by sevoflurane, leading to inhibition of sensory information transmission in the cerebellar cortex, field potential responses of PCs and the development of cerebellar motor function. The present study provided experimental evidence for the safe usage of sevoflurane in clinical anesthesia, and suggested that GABAA‑R ε subunit antagonists may be considered for combined application with general anesthesia with repeated inhalation of sevoflurane, for adverse effect prevention in the clinic.

Hypercapnia shortens emergence time from inhaled anesthesia in pigs.

PubMed

Gopalakrishnan, Nishant A; Sakata, Derek J; Orr, Joseph A; McJames, Scott; Westenskow, Dwayne R

2007-04-01

Anesthetic clearance from the lungs and the circle rebreathing system can be maximized using hyperventilation and high fresh gas flows. However, the concomitant clearance of CO2 decreases PAco2, thereby decreasing cerebral blood flow and slowing the clearance of anesthetic from the brain. This study shows that in addition to hyperventilation, hypercapnia (CO2 infusion or rebreathing) is a significant factor in decreasing emergence time from inhaled anesthesia. We anesthetized seven pigs with 2 MACPIG of isoflurane and four with 2 MACPIG of sevoflurane. After 2 h, anesthesia was discontinued, and the animals were hyperventilated. The time to movement of multiple limbs was measured under hypocapnic (end-tidal CO2 = 22 mm Hg) and hypercapnic (end-tidal CO2 = 55 mm Hg) conditions. The time between turning off the vaporizer and to movement of multiple limbs was faster with hypercapnia during hyperventilation. Emergence time from isoflurane and sevoflurane anesthesia was shortened by an average of 65% with rebreathing or with the use of a CO2 controller (P < 0.05). Hypercapnia, along with hyperventilation, may be used clinically to decrease emergence time from inhaled anesthesia. These time savings might reduce drug costs. In addition, higher PAco2 during emergence may enhance respiratory drive and airway protection after tracheal extubation.

Electroacupuncture-Assisted Craniotomy on an Awake Patient.

PubMed

Sidhu, Amritpal; Murgahayah, Trushna; Narayanan, Vairavan; Chandran, Hari; Waran, Vicknes

2017-01-01

Although acupuncture has existed for over 2000 years, its application as an anesthetic aid began in the 1950s in China. The first surgical procedure performed under acupuncture anesthesia was a tonsillectomy. Soon thereafter, major and minor surgical procedures took place with electroacupuncture alone providing the anesthesia. The procedures performed were diverse, ranging from cardiothoracic surgery to dental extractions. Usage of acupuncture anesthesia, specifically in neurosurgery, has been well documented in hospitals across China, especially in Beijing, dating back to the 1970s. We present a case of a 65-year-old man who presented with right-sided body weakness. He had a past medical history of uncontrolled diabetes mellitus, hypertension, and obstructive sleep apnea requiring use of a nasal continuous positive airway pressure device during sleep. We performed a computed tomography brain scan, which revealed a left-sided acute on chronic subdural hemorrhage. Due to his multiple comorbidities, we decided to perform the surgical procedure under electroacupuncture anesthesia. The aim of this case report is to describe a craniotomy performed under electroacupuncture on an elderly patient with multiple comorbidities who was awake during the procedure and in whom this procedure, if it had been performed under general anesthesia, would have carried high risk. Copyright © 2016 Medical Association of Pharmacopuncture Institute. Published by Elsevier B.V. All rights reserved.

Specificities of Awake Craniotomy and Brain Mapping in Children for Resection of Supratentorial Tumors in the Language Area.

PubMed

Delion, Matthieu; Terminassian, Aram; Lehousse, Thierry; Aubin, Ghislaine; Malka, Jean; N'Guyen, Sylvie; Mercier, Philippe; Menei, Philippe

2015-12-01

In the pediatric population, awake craniotomy began to be used for the resection of brain tumor located close to eloquent areas. Some specificities must be taken into account to adapt this method to children. The aim of this clinical study is to not only confirm the feasibility of awake craniotomy and language brain mapping in the pediatric population but also identify the specificities and necessary adaptations of the procedure. Six children aged 11 to 16 were operated on while awake under local anesthesia with language brain mapping for supratentorial brain lesions (tumor and cavernoma). The preoperative planning comprised functional magnetic resonance imaging (MRI) and neuropsychologic and psychologic assessment. The specific preoperative preparation is clearly explained including hypnosis conditioning and psychiatric evaluation. The success of the procedure was based on the ability to perform the language brain mapping and the tumor removal without putting the patient to sleep. We investigated the pediatric specificities, psychological experience, and neuropsychologic follow-up. The children experienced little anxiety, probably in large part due to the use of hypnosis. We succeeded in doing the cortical-subcortical mapping and removing the tumor without putting the patient to sleep in all cases. The psychological experience was good, and the neuropsychologic follow-up showed a favorable evolution. Preoperative preparation and hypnosis in children seemed important for performing awake craniotomy and contributing language brain mapping with the best possible psychological experience. The pediatrics specificities are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

Temporal Processing in the Visual Cortex of the Awake and Anesthetized Rat.

PubMed

Aasebø, Ida E J; Lepperød, Mikkel E; Stavrinou, Maria; Nøkkevangen, Sandra; Einevoll, Gaute; Hafting, Torkel; Fyhn, Marianne

2017-01-01

The activity pattern and temporal dynamics within and between neuron ensembles are essential features of information processing and believed to be profoundly affected by anesthesia. Much of our general understanding of sensory information processing, including computational models aimed at mathematically simulating sensory information processing, rely on parameters derived from recordings conducted on animals under anesthesia. Due to the high variety of neuronal subtypes in the brain, population-based estimates of the impact of anesthesia may conceal unit- or ensemble-specific effects of the transition between states. Using chronically implanted tetrodes into primary visual cortex (V1) of rats, we conducted extracellular recordings of single units and followed the same cell ensembles in the awake and anesthetized states. We found that the transition from wakefulness to anesthesia involves unpredictable changes in temporal response characteristics. The latency of single-unit responses to visual stimulation was delayed in anesthesia, with large individual variations between units. Pair-wise correlations between units increased under anesthesia, indicating more synchronized activity. Further, the units within an ensemble show reproducible temporal activity patterns in response to visual stimuli that is changed between states, suggesting state-dependent sequences of activity. The current dataset, with recordings from the same neural ensembles across states, is well suited for validating and testing computational network models. This can lead to testable predictions, bring a deeper understanding of the experimental findings and improve models of neural information processing. Here, we exemplify such a workflow using a Brunel network model.

Temporal Processing in the Visual Cortex of the Awake and Anesthetized Rat

PubMed Central

Aasebø, Ida E. J.; Stavrinou, Maria; Nøkkevangen, Sandra; Einevoll, Gaute

2017-01-01

Abstract The activity pattern and temporal dynamics within and between neuron ensembles are essential features of information processing and believed to be profoundly affected by anesthesia. Much of our general understanding of sensory information processing, including computational models aimed at mathematically simulating sensory information processing, rely on parameters derived from recordings conducted on animals under anesthesia. Due to the high variety of neuronal subtypes in the brain, population-based estimates of the impact of anesthesia may conceal unit- or ensemble-specific effects of the transition between states. Using chronically implanted tetrodes into primary visual cortex (V1) of rats, we conducted extracellular recordings of single units and followed the same cell ensembles in the awake and anesthetized states. We found that the transition from wakefulness to anesthesia involves unpredictable changes in temporal response characteristics. The latency of single-unit responses to visual stimulation was delayed in anesthesia, with large individual variations between units. Pair-wise correlations between units increased under anesthesia, indicating more synchronized activity. Further, the units within an ensemble show reproducible temporal activity patterns in response to visual stimuli that is changed between states, suggesting state-dependent sequences of activity. The current dataset, with recordings from the same neural ensembles across states, is well suited for validating and testing computational network models. This can lead to testable predictions, bring a deeper understanding of the experimental findings and improve models of neural information processing. Here, we exemplify such a workflow using a Brunel network model. PMID:28791331

Understanding of anesthesia – Why consciousness is essential for life and not based on genes

PubMed Central

Baluška, František; Yokawa, Ken; Mancuso, Stefano; Baverstock, Keith

2016-01-01

ABSTRACT Anesthesia and consciousness represent 2 mysteries not only for biology but also for physics and philosophy. Although anesthesia was introduced to medicine more than 160 y ago, our understanding of how it works still remains a mystery. The most prevalent view is that the human brain and its neurons are necessary to impose the effects of anesthetics. However, the fact is that all life can be anesthesized. Numerous theories have been generated trying to explain the major impact of anesthetics on our human-specific consciousness; switching it off so rapidly, but no single theory resolves this enduring mystery. The speed of anesthetic actions precludes any direct involvement of genes. Lipid bilayers, cellular membranes, and critical proteins emerge as the most probable primary targets of anesthetics. Recent findings suggest, rather surprisingly, that physical forces underlie both the anesthetic actions on living organisms as well as on consciousness in general. PMID:28042377

Understanding of anesthesia - Why consciousness is essential for life and not based on genes.

PubMed

Baluška, František; Yokawa, Ken; Mancuso, Stefano; Baverstock, Keith

2016-01-01

Anesthesia and consciousness represent 2 mysteries not only for biology but also for physics and philosophy. Although anesthesia was introduced to medicine more than 160 y ago, our understanding of how it works still remains a mystery. The most prevalent view is that the human brain and its neurons are necessary to impose the effects of anesthetics. However, the fact is that all life can be anesthesized. Numerous theories have been generated trying to explain the major impact of anesthetics on our human-specific consciousness; switching it off so rapidly, but no single theory resolves this enduring mystery. The speed of anesthetic actions precludes any direct involvement of genes. Lipid bilayers, cellular membranes, and critical proteins emerge as the most probable primary targets of anesthetics. Recent findings suggest, rather surprisingly, that physical forces underlie both the anesthetic actions on living organisms as well as on consciousness in general.

Examiner's finger-mounted near-infrared spectroscopy is feasible to analyze cerebral and skeletal muscle oxygenation in conscious Chihuahuas

NASA Astrophysics Data System (ADS)

Hiwatashi, Keisuke; Doi, Kimiaki; Mizuno, Risuke; Yokosuka, Makoto

2017-02-01

To measure regional saturation of oxygen (rSO2) of hemoglobin and total hemoglobin index (HbI) in the brain (through the molera of the head) and skeletal muscle (musculus gracilis) of conscious Chihuahua dogs using an examiner's finger-mounted near-infrared spectroscopy (NIRS) device, Toccare, we investigated brain and skeletal muscle NIRS in 48 Chihuahuas without severe disease. To measure rSO2 and total HbI, a Toccare probe was placed on the molera of the head and musculus gracilis of each dog for real-time recording. Stable NIRS values were obtained within 10 s. We also examined the effect of anesthesia on rSO2 and total HbI of a Chihuahua. Cerebral rSO2 values (59%±7%) were significantly lower than those obtained at femoral regions (67%±6%), whereas total HbI values in the brain (0.38±0.09) were significantly higher than those of the musculus gracilis (0.20±0.05). Sedation with a combination of medetomidine and ketamine decreased cerebral rSO2 along with a corresponding reduction in heart rate. Sevoflurane anesthesia with 100% O2 maintained rSO2 in the brain with an even lower heart rate. In conclusions, we measured brain and skeletal muscle rSO2 of hemoglobin in conscious Chihuahuas using a newly developed NIRS device, Toccare, and found that changes in cerebral oxygenation levels were associated with administration of anesthetics.

Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baba, Justin S; Endres, Christopher; Foss, Catherine

2013-01-01

We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a 99mTc-pertechnetate phantom, 99mTcmethylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand 123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained frommore » CT. The binding potential of 123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.« less

Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baba, Justin S.; Endres, Christopher J.; Foss, Catherine A.

2013-06-01

We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a ^99mTc-pertechnetate phantom, ^99mTc-methylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand ^123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained frommore » CT. The binding potential of ^123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.« less

Awake craniotomy may further improve neurological outcome of intraoperative MRI-guided brain tumor surgery.

PubMed

Tuominen, Juho; Yrjänä, Sanna; Ukkonen, Anssi; Koivukangas, John

2013-10-01

Results of awake craniotomy are compared to results of resections done under general anesthesia in patients operated with IMRI control. We hypothesized that stimulation of the cortex and white matter during awake surgery supplements IMRI control allowing for safer resection of eloquent brain area tumors. The study group consisted of 20 consecutive patients undergoing awake craniotomy with IMRI control. Resection outcome of these patients was compared to a control group of 20 patients operated in the same IMRI suite but under general anesthesia without cortical stimulation. The control group was composed of those patients whose age, sex, tumor location, recurrence and histology best matched to patients in study group. Cortical stimulation identified functional cortex in eight patients (40 %). Postoperatively the neurological condition in 16 patients (80 %) in the study group was unchanged or improved compared with 13 patients (65 %) in the control group. In both groups, three patients (15 %) had transient impairment symptoms. There was one patient (5 %) with permanent neurological impairment in the study group compared to four patients (20 %) in the control group. These differences between groups were not statistically significant. There was no surgical mortality in either group and the overall infection rate was 5 %. Mean operation time was 4 h 45 min in the study group and 3 h 15 min in the control group. The study consisted of a limited patient series, but it implies that awake craniotomy with bipolar cortical stimulation may help to reduce the risk of postoperative impairment following resection of tumors located in or near speech and motor areas also under IMRI control.

Scalp acupuncture attenuates neurological deficits in a rat model of hemorrhagic stroke.

PubMed

Liu, Hao; Sun, Xiaowei; Zou, Wei; Leng, Mengtong; Zhang, Beng; Kang, Xiaoyu; He, Tao; Wang, Hui

2017-06-01

Hemorrhagic stroke accounts for approximately 15% of all stroke cases, and is associated with high morbidity and mortality. Limited human studies suggested that scalp acupuncture could facilitate functional recovery after cerebral hemorrhage. In the current study, we used an animal model of cerebral hemorrhage to examine the potential effects of scalp acupuncture. Adult male Sprague-Dawley rats received autologous blood (50μL) into the right caudate nucleus on the right side under pentobarbital anesthesia, and then received scalp acupuncture (DU20 through GB7 on the lesion side) or sham acupuncture (1cm to the right side of the acupoints) (n=10 per group). A group of rats receiving autologous blood into the caudate nucleus but no other intervention, as well as a group of rats receiving anesthesia but no blood injection to the brain (n=10 per group) were included as additional controls. Composite neuroscore, corner turn test, forelimb placing test, wire hang task and beam walking were used to evaluate the behavior of rats. Hematoxylin and Eosin (HE) staining was used to observe the histopathological changes. Western blot was used to detect the content of tumor necrosis factor alpha (TNF-α) and nuclear factor-KappaB (NFκB) protein expression. Scalp acupuncture attenuated neurological deficits (p<0.01 or <0.05 vs. sham acupuncture using a variety of behavioral tests) at 1-7days after the treatment. The brain content of TNF-α and NFκB was decreased (p<0.01 for both). Scalp acupuncture could improve neurological deficits in a rat model of hemorrhagic stroke. Copyright © 2017 Elsevier Ltd. All rights reserved.

The abolishment of anesthesia-induced cognitive impairment by timely protection of mitochondria in the developing rat brain: the importance of free oxygen radicals and mitochondrial integrity.

PubMed

Boscolo, A; Starr, J A; Sanchez, V; Lunardi, N; DiGruccio, M R; Ori, C; Erisir, A; Trimmer, P; Bennett, J; Jevtovic-Todorovic, V

2012-03-01

Early exposure to general anesthesia (GA) causes developmental neuroapoptosis in the mammalian brain and long-term cognitive impairment. Recent evidence suggests that GA also causes functional and morphological impairment of the immature neuronal mitochondria. Injured mitochondria could be a significant source of reactive oxygen species (ROS), which, if not scavenged in timely fashion, may cause excessive lipid peroxidation and damage of cellular membranes. We examined whether early exposure to GA results in ROS upregulation and whether mitochondrial protection and ROS scavenging prevent GA-induced pathomorphological and behavioral impairments. We exposed 7-day-old rats to GA with or without either EUK-134, a synthetic ROS scavenger, or R(+) pramipexole (PPX), a synthetic aminobenzothiazol derivative that restores mitochondrial integrity. We found that GA causes extensive ROS upregulation and lipid peroxidation, as well as mitochondrial injury and neuronal loss in the subiculum. As compared to rats given only GA, those also given PPX or EUK-134 had significantly downregulated lipid peroxidation, preserved mitochondrial integrity, and significantly less neuronal loss. The subiculum is highly intertwined with the hippocampal CA1 region, anterior thalamic nuclei, and both entorhinal and cingulate cortices; hence, it is important in cognitive development. We found that PPX or EUK-134 co-treatment completely prevented GA-induced cognitive impairment. Because mitochondria are vulnerable to GA-induced developmental neurotoxicity, they could be an important therapeutic target for adjuvant therapy aimed at improving the safety of commonly used GAs. Copyright © 2011 Elsevier Inc. All rights reserved.

Simulation Training for the Office-Based Anesthesia Team.

PubMed

Ritt, Richard M; Bennett, Jeffrey D; Todd, David W

2017-05-01

An OMS office is a complex environment. Within such an environment, a diverse scope of complex surgical procedures is performed with different levels of anesthesia, ranging from local anesthesia to general anesthesia, on patients with varying comorbidities. Optimal patient outcomes require a functional surgical and anesthetic team, who are familiar with both standard operational principles and emergency recognition and management. Offices with high volume and time pressure add further stress and potential risk to the office environment. Creating and maintaining a functional surgical and anesthetic team that is competent with a culture of patient safety and risk reduction is a significant challenge that requires time, commitment, planning, and dedication. This article focuses on the role of simulation training in office training and preparation. Copyright © 2017 Elsevier Inc. All rights reserved.

Propofol disrupts functional interactions between sensory and high-order processing of auditory verbal memory.

PubMed

Liu, Xiaolin; Lauer, Kathryn K; Ward, Barney D; Rao, Stephen M; Li, Shi-Jiang; Hudetz, Anthony G

2012-10-01

Current theories suggest that disrupting cortical information integration may account for the mechanism of general anesthesia in suppressing consciousness. Human cognitive operations take place in hierarchically structured neural organizations in the brain. The process of low-order neural representation of sensory stimuli becoming integrated in high-order cortices is also known as cognitive binding. Combining neuroimaging, cognitive neuroscience, and anesthetic manipulation, we examined how cognitive networks involved in auditory verbal memory are maintained in wakefulness, disrupted in propofol-induced deep sedation, and re-established in recovery. Inspired by the notion of cognitive binding, an functional magnetic resonance imaging-guided connectivity analysis was utilized to assess the integrity of functional interactions within and between different levels of the task-defined brain regions. Task-related responses persisted in the primary auditory cortex (PAC), but vanished in the inferior frontal gyrus (IFG) and premotor areas in deep sedation. For connectivity analysis, seed regions representing sensory and high-order processing of the memory task were identified in the PAC and IFG. Propofol disrupted connections from the PAC seed to the frontal regions and thalamus, but not the connections from the IFG seed to a set of widely distributed brain regions in the temporal, frontal, and parietal lobes (with exception of the PAC). These later regions have been implicated in mediating verbal comprehension and memory. These results suggest that propofol disrupts cognition by blocking the projection of sensory information to high-order processing networks and thus preventing information integration. Such findings contribute to our understanding of anesthetic mechanisms as related to information and integration in the brain. Copyright © 2011 Wiley Periodicals, Inc.

Diabetic Goto-Kakizaki rats display pronounced hyperglycemia and longer-lasting cognitive impairments following ischemia induced by cortical compression.

PubMed

Moreira, T; Cebers, G; Pickering, C; Ostenson, C-G; Efendic, S; Liljequist, S

2007-02-23

Hyperglycemia has been shown to worsen the outcome of brain ischemia in several animal models but few experimental studies have investigated impairments in cognition induced by ischemic brain lesions in hyperglycemic animals. The Goto-Kakizaki (GK) rat naturally develops type 2 diabetes characterized by mild hyperglycemia and insulin resistance. We hypothesized that GK rats would display more severe cerebral damage due to hyperglycemia-aggravated brain injury and, accordingly, more severe cognitive impairments. In this study, recovery of motor and cognitive functions of GK and healthy Wistar rats was examined following extradural compression (EC) of the sensorimotor cortex. For this purpose, tests of vestibulomotor function (beam-walking) and combined tests of motor function and learning (locomotor activity from day (D) 1 to D5, operant lever-pressing from D14 to D25) were used. EC consistently reduced cerebral blood flow in both strains. Anesthesia-challenge and EC resulted in pronounced hyperglycemia in GK but not in Wistar rats. Lower beam-walking scores, increased locomotor activity, impairments in long-term habituation and learning of operant lever-pressing were more pronounced and observed at later time-points in GK rats. Fluoro-Jade, a marker of irreversible neuronal degeneration, revealed consistent degeneration in the ipsilateral cortex, hippocampus and thalamus at 2, 7 and 14 days post-compression. The amount of degeneration in these structures was considerably higher in GK rats. Thus, GK rats exhibited marked hyperglycemia during EC, as well as longer-lasting behavioral deficits and increased neurodegeneration during recovery. The GK rat is thus an attractive model for neuropathologic and cognitive studies after ischemic brain injury in hyperglycemic rats.

Patient acceptance of awake craniotomy.

PubMed

Wrede, Karsten H; Stieglitz, Lennart H; Fiferna, Antje; Karst, Matthias; Gerganov, Venelin M; Samii, Madjid; von Gösseln, Hans-Henning; Lüdemann, Wolf O

2011-12-01

The aim of this study was to objectively assess the patients' acceptance for awake craniotomy in a group of neurosurgical patients, who underwent this procedure for removal of lesions in or close to eloquent brain areas. Patients acceptance for awake craniotomy under local anesthesia and conscious sedation was assessed by a formal questionnaire (PPP33), initially developed for general surgery patients. The results are compared to a group of patients who had brain surgery under general anesthesia and to previously published data. The awake craniotomy (AC) group consisted of 37 male and 9 female patients (48 craniotomies) with age ranging from 18 to 71 years. The general anesthesia (GA) group consisted of 26 male and 15 female patients (43 craniotomies) with age ranging from 26 to 83 years. All patients in the study were included in the questionnaire analysis. In comparison to GA the overall PPP33 score for AC was higher (p=0.07), suggesting better overall acceptance for AC. The subscale scores for AC were also significantly better compared to GA for the two subscales "postoperative pain" (p=0.02) and "physical disorders" (p=0.01) and equal for the other 6 subscales. The results of the overall mean score and the scores for the subscales of the PPP33 questionnaire verify good patients' acceptance for AC. Previous studies have shown good patients' acceptance for awake craniotomy, but only a few times using formal approaches. By utilizing a formal questionnaire we could verify good patient acceptance for awake craniotomy for the treatment of brain tumors in or close to eloquent areas. This is a novel approach that substantiates previously published experiences. Copyright © 2011 Elsevier B.V. All rights reserved.

Regional or general anesthesia for fast-track hip and knee replacement - what is the evidence?

PubMed Central

Kehlet, Henrik; Aasvang, Eske Kvanner

2015-01-01

Regional anesthesia for knee and hip arthroplasty may have favorable outcome effects compared with general anesthesia by effectively blocking afferent input, providing initial postoperative analgesia, reducing endocrine metabolic responses, and providing sympathetic blockade with reduced bleeding and less risk of thromboembolic complications but with undesirable effects on lower limb motor and urinary bladder function. Old randomized studies supported the use of regional anesthesia with fewer postoperative pulmonary and thromboembolic complications, and this has been supported by recent large non-randomized epidemiological database cohort studies. In contrast, the data from newer randomized trials are conflicting, and recent studies using modern general anesthetic techniques may potentially support the use of general versus spinal anesthesia. In summary, the lack of properly designed large randomized controlled trials comparing modern general anesthesia and spinal anesthesia for knee and hip arthroplasty prevents final recommendations and calls for prospective detailed studies in this clinically important field. PMID:26918127

Total Laparoscopic Hysterectomy Under Regional Anesthesia.

PubMed

Moawad, Nash S; Santamaria Flores, Estefania; Le-Wendling, Linda; Sumner, Martina T; Enneking, F Kayser

2018-05-07

Laparoscopic hysterectomies comprise a large proportion of all hysterectomies in the United States. Procedures completed under regional anesthesia pose a number of benefits to patients, but laparoscopic hysterectomies traditionally have been performed under general anesthesia. We describe a case of total laparoscopic hysterectomy under epidural anesthesia with the patient fully awake. A 51-year-old woman with abnormal uterine bleeding underwent an uncomplicated total laparoscopic hysterectomy, bilateral salpingectomy, and excision of endometriosis. The procedure was completed under epidural anesthesia without intravenous sedation or systemic narcotics. Pneumoperitoneum with a pressure of 12 mm Hg and Trendelenburg to 15° allowed for adequate visualization. Anesthesia was achieved with midthoracic and low lumbar epidural catheters. Bilevel positive airway pressure was used for augmentation of respiratory function. With a committed patient, adequate planning, and knowledge of the potential intraoperative complications, regional anesthesia is an option for select women undergoing laparoscopic hysterectomy.

Sevoflurane anesthesia during acute right ventricular ischemia in pigs preserves cardiac function better than propofol anesthesia.

PubMed

Haraldsen, Pernille; Metzsch, Carsten; Lindstedt, Sandra; Algotsson, Lars; Ingemansson, Richard

2016-09-01

The intention of the present study was to evaluate possible cardioprotective properties of inhalation anesthesia with sevoflurane. A porcine, open-chest model of right ventricular ischemia was used in 7 pigs receiving inhalation anesthesia with sevoflurane. The model was earlier developed and published by our group, using pigs receiving intravenous anesthesia with propofol. They served as controls. The animals were observed for three hours after the induction of right ventricular ischemia by ligation of the main branches supplying the right ventricular free wall. In the sevoflurane group, the cardiac output recovered 2 hours after the induction of ischemia and intact right ventricular stroke work was observed. In the propofol group, no such recovery occurred. The release of troponin T was significantly lower than in the sevoflurane group. Inhalation anesthesia with sevoflurane seems superior to intravenous anesthesia with propofol in acute right ventricular ischemic dysfunction. © The Author(s) 2016.

Enhanced Burst-Suppression and Disruption of Local Field Potential Synchrony in a Mouse Model of Focal Cortical Dysplasia Exhibiting Spike-Wave Seizures.

PubMed

Williams, Anthony J; Zhou, Chen; Sun, Qian-Quan

2016-01-01

Focal cortical dysplasias (FCDs) are a common cause of brain seizures and are often associated with intractable epilepsy. Here we evaluated aberrant brain neurophysiology in an in vivo mouse model of FCD induced by neonatal freeze lesions (FLs) to the right cortical hemisphere (near S1). Linear multi-electrode arrays were used to record extracellular potentials from cortical and subcortical brain regions near the FL in anesthetized mice (5-13 months old) followed by 24 h cortical electroencephalogram (EEG) recordings. Results indicated that FL animals exhibit a high prevalence of spontaneous spike-wave discharges (SWDs), predominately during sleep (EEG), and an increase in the incidence of hyper-excitable burst/suppression activity under general anesthesia (extracellular recordings, 0.5%-3.0% isoflurane). Brief periods of burst activity in the local field potential (LFP) typically presented as an arrhythmic pattern of increased theta-alpha spectral peaks (4-12 Hz) on a background of low-amplitude delta activity (1-4 Hz), were associated with an increase in spontaneous spiking of cortical neurons, and were highly synchronized in control animals across recording sites in both cortical and subcortical layers (average cross-correlation values ranging from +0.73 to +1.0) with minimal phase shift between electrodes. However, in FL animals, cortical vs. subcortical burst activity was strongly out of phase with significantly lower cross-correlation values compared to controls (average values of -0.1 to +0.5, P < 0.05 between groups). In particular, a marked reduction in the level of synchronous burst activity was observed, the closer the recording electrodes were to the malformation (Pearson's Correlation = 0.525, P < 0.05). In a subset of FL animals (3/9), burst activity also included a spike or spike-wave pattern similar to the SWDs observed in unanesthetized animals. In summary, neonatal FLs increased the hyperexcitable pattern of burst activity induced by anesthesia and disrupted field potential synchrony between cortical and subcortical brain regions near the site of the cortical malformation. Monitoring the altered electrophysiology of burst activity under general anesthesia with multi-dimensional micro-electrode arrays may serve to define distinct neurophysiological biomarkers of epileptogenesis in human brain and improve techniques for surgical resection of epileptogenic malformed brain tissue.

A Procedural Electroencephalogram Simulator for Evaluation of Anesthesia Monitors.

PubMed

Petersen, Christian Leth; Görges, Matthias; Massey, Roslyn; Dumont, Guy Albert; Ansermino, J Mark

2016-11-01

Recent research and advances in the automation of anesthesia are driving the need to better understand electroencephalogram (EEG)-based anesthesia end points and to test the performance of anesthesia monitors. This effort is currently limited by the need to collect raw EEG data directly from patients. A procedural method to synthesize EEG signals was implemented in a mobile software application. The application is capable of sending the simulated signal to an anesthesia depth of hypnosis monitor. Systematic sweeps of the simulator generate functional monitor response profiles reminiscent of how network analyzers are used to test electronic components. Three commercial anesthesia monitors (Entropy, NeuroSENSE, and BIS) were compared with this new technology, and significant response and feature variations between the monitor models were observed; this includes reproducible, nonmonotonic apparent multistate behavior and significant hysteresis at light levels of anesthesia. Anesthesia monitor response to a procedural simulator can reveal significant differences in internal signal processing algorithms. The ability to synthesize EEG signals at different anesthetic depths potentially provides a new method for systematically testing EEG-based monitors and automated anesthesia systems with all sensor hardware fully operational before human trials.

Hardware, software, and scanning issues encountered during small animal imaging of photodynamic therapy in the athymic nude rat

NASA Astrophysics Data System (ADS)

Cross, Nathan; Sharma, Rahul; Varghai, Davood; Spring-Robinson, Chandra; Oleinick, Nancy L.; Muzic, Raymond F., Jr.; Dean, David

2007-02-01

Small animal imaging devices are now commonly used to study gene activation and model the effects of potential therapies. We are attempting to develop a protocol that non-invasively tracks the affect of Pc 4-mediated photodynamic therapy (PDT) in a human glioma model using structural image data from micro-CT and/or micro-MR scanning and functional data from 18F-fluorodeoxy-glucose (18F-FDG) micro-PET imaging. Methods: Athymic nude rat U87-derived glioma was imaged by micro-PET and either micro-CT or micro-MR prior to Pc 4-PDT. Difficulty insuring animal anesthesia and anatomic position during the micro-PET, micro-CT, and micro-MR scans required adaptation of the scanning bed hardware. Following Pc 4-PDT the animals were again 18F-FDG micro-PET scanned, euthanized one day later, and their brains were explanted and prepared for H&E histology. Histology provided the gold standard for tumor location and necrosis. The tumor and surrounding brain functional and structural image data were then isolated and coregistered. Results: Surprisingly, both the non-PDT and PDT groups showed an increase in tumor functional activity when we expected this signal to disappear in the group receiving PDT. Co-registration of the functional and structural image data was done manually. Discussion: As expected, micro-MR imaging provided better structural discrimination of the brain tumor than micro-CT. Contrary to expectations, in our preliminary analysis 18F-FDG micro-PET imaging does not readily discriminate the U87 tumors that received Pc 4-PDT. We continue to investigate the utility of micro-PET and other methods of functional imaging to remotely detect the specificity and sensitivity of Pc 4-PDT in deeply placed tumors.

Two-photon microscopy measurement of CMRO2 using periarteriolar PO2 gradients(Conference Presentation)

NASA Astrophysics Data System (ADS)

Sakadžić, Sava; Yaseen, Mohammad A.; Jaswal, Rajeshwer S.; Roussakis, Emmanuel; Dale, Anders M.; Buxton, Richard B.; Vinogradov, Sergei A.; Boas, David A.; Devor, Anna

2017-02-01

The cerebral metabolic rate of oxygen (CMRO2) is an essential parameter for evaluating brain function and pathophysiology. Measurements of CMRO2 with high spatio-temporal resolution are critically important for understanding how the brain copes with metabolic and blood perfusion changes associated with various clinical conditions, such as stroke, periinfarct depolarizations, and various microvasculopathies (e.g., Alzheimer's disease, chronic hypertension). CMRO2 measurements are also important for understanding the physiological underpinnings of functional Magnetic Resonance Imaging signals. However, the currently available approaches for quantifying CMRO2 rely on complex multimodal imaging and mathematical modeling. Here, we introduce a novel method that allows estimation of CMRO2 based on a single measurement modality - two-photon phosphorescence lifetime microscopy (2PLM) imaging of the partial pressure of oxygen (PO2) in cortical tissue. CMRO2 is estimated by fitting the changes of tissue PO2 around cortical penetrating arterioles with the Krogh cylinder model of oxygen diffusion. We measured the baseline CMRO2 in anesthetized rats, and modulated tissue PO2 levels by manipulating the depth of anesthesia. This method has a spatial resolution of approximately 200 μm and it may provide CMRO2 measurements in individual cortical layers or within confined cortical regions such as in ischemic penumbra and the foci of functional activation.

REPERTOIRE OF MESOSCOPIC CORTICAL ACTIVITY IS NOT REDUCED DURING ANESTHESIA

PubMed Central

HUDETZ, ANTHONY G.; VIZUETE, JEANNETTE A.; PILLAY, SIVESHIGAN; MASHOUR, GEORGE A.

2016-01-01

Consciousness has been linked to the repertoire of brain states at various spatiotemporal scales. Anesthesia is thought to modify consciousness by altering information integration in cortical and thalamocortical circuits. At a mesoscopic scale, neuronal populations in the cortex form synchronized ensembles whose characteristics are presumably state-dependent but this has not been rigorously tested. In this study, spontaneous neuronal activity was recorded with 64-contact microelectrode arrays in primary visual cortex of chronically instrumented, unrestrained rats under stepwise decreasing levels of desflurane anesthesia (8%, 6%, 4%, and 2% inhaled concentrations) and wakefulness (0% concentration). Negative phases of the local field potentials formed compact, spatially contiguous activity patterns (CAPs) that were not due to chance. The number of CAPs was 120% higher in wakefulness and deep anesthesia associated with burst-suppression than at intermediate levels of consciousness. The frequency distribution of CAP sizes followed a power–law with slope −1.5 in relatively deep anesthesia (8–6%) but deviated from that at the lighter levels. Temporal variance and entropy of CAP sizes were lowest in wakefulness (76% and 24% lower at 0% than at 8% desflurane, respectively) but changed little during recovery of consciousness. CAPs categorized by K-means clustering were conserved at all anesthesia levels and wakefulness, although their proportion changed in a state-dependent manner. These observations yield new knowledge about the dynamic landscape of ongoing population activity in sensory cortex at graded levels of anesthesia. The repertoire of population activity and self-organized criticality at the mesoscopic scale do not appear to contribute to anesthetic suppression of consciousness, which may instead depend on large-scale effects, more subtle dynamic properties, or changes outside of primary sensory cortex. PMID:27751957

Repertoire of mesoscopic cortical activity is not reduced during anesthesia.

PubMed

Hudetz, Anthony G; Vizuete, Jeannette A; Pillay, Siveshigan; Mashour, George A

2016-12-17

Consciousness has been linked to the repertoire of brain states at various spatiotemporal scales. Anesthesia is thought to modify consciousness by altering information integration in cortical and thalamocortical circuits. At a mesoscopic scale, neuronal populations in the cortex form synchronized ensembles whose characteristics are presumably state-dependent but this has not been rigorously tested. In this study, spontaneous neuronal activity was recorded with 64-contact microelectrode arrays in primary visual cortex of chronically instrumented, unrestrained rats under stepwise decreasing levels of desflurane anesthesia (8%, 6%, 4%, and 2% inhaled concentrations) and wakefulness (0% concentration). Negative phases of the local field potentials formed compact, spatially contiguous activity patterns (CAPs) that were not due to chance. The number of CAPs was 120% higher in wakefulness and deep anesthesia associated with burst-suppression than at intermediate levels of consciousness. The frequency distribution of CAP sizes followed a power-law with slope -1.5 in relatively deep anesthesia (8-6%) but deviated from that at the lighter levels. Temporal variance and entropy of CAP sizes were lowest in wakefulness (76% and 24% lower at 0% than at 8% desflurane, respectively) but changed little during recovery of consciousness. CAPs categorized by K-means clustering were conserved at all anesthesia levels and wakefulness, although their proportion changed in a state-dependent manner. These observations yield new knowledge about the dynamic landscape of ongoing population activity in sensory cortex at graded levels of anesthesia. The repertoire of population activity and self-organized criticality at the mesoscopic scale do not appear to contribute to anesthetic suppression of consciousness, which may instead depend on large-scale effects, more subtle dynamic properties, or changes outside of primary sensory cortex. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Real-time optoacoustic monitoring of stroke

NASA Astrophysics Data System (ADS)

Kneipp, Moritz; Turner, Jake; Hambauer, Sebastian; Krieg, Sandro M.; Lehmberg, Jens; Lindauer, Ute; Razansky, Daniel

2014-03-01

Characterizing disease progression and identifying possible therapeutic interventions in stroke is greatly aided by the use of longitudinal function imaging studies. In this study, we investigate the applicability of real-time multispectral optoacoustic tomography (MSOT) as a tool for non-invasive monitoring of the progression of stroke in the whole brain. The middle cerebral artery occlusion (MCAO) method was used to induce stroke. Mice were imaged under isoflurane anesthesia preoperatively and at several time points during and after the 60-minute occlusion. The animals were sacrificed after 24 hours and their excised brains frozen at -80°C for sectioning. The cryosection were stained using H&E staining to identify the ischemic lesion. Major vessels are readily identifiable in the whole mouse head in the in vivo optoacoustic scans. During ischemia, a reduction in cerebral blood volume is detectable in the cortex. Post ischemia, spectral unmixing of the optoacoustic signals shows an asymmetry of the deoxygenated hemoglobin in the hemisphere affected by MCAO. This hypoxic area was mainly located around the boundary of the ischemic lesion and was therefore identified as the ischemic penumbra. Non-invasive functional MSOT imaging is able to visualize the hypoxic penumbra in brains affected by stroke. Stopping the spread of the infarct area and revitalizing the penumbra is central in stroke research, this new imaging technique may therefore prove to be a valuable tool in the monitoring and developing new treatments.

Rat Models and Identification of Candidate Early Serum Biomarkers of Battlefield Traumatic Brain Injury

DTIC Science & Technology

2007-07-31

brain injury) All surgeries were performed using aseptic technique. Animals were checked for pain /distress immediately prior to anesthesia/surgery... Pain /distress checks were performed at 3, 6, 12, 24, 36, 48, 60, and 72 hours post-injury. Fluid Percussion Injury (FPI) For animals in the...NIH), and Neurobehavioral Scale (NBS). The criteria used to obtain the scores are detailed in Tables 2 and 3. As an additional endpoint, we also

Anesthetics and analgesics in experimental traumatic brain injury: Selection based on experimental objectives

PubMed Central

Rowe, Rachel K.; Harrison, Jordan L.; Thomas, Theresa C.; Pauly, James R.; Adelson, P. David; Lifshitz, Jonathan

2013-01-01

The use of animal modeling in traumatic brain injury (TBI) research is justified by the lack of sufficiently comprehensive in vitro and computer modeling that incorporates all components of the neurovascular unit. Valid animal modeling of TBI requires accurate replication of both the mechanical forces and secondary injury conditions observed in human patients. Regulatory requirements for animal modeling emphasize the administration of appropriate anesthetics and analgesics unless withholding these drugs is scientifically justified. The objective of this review is to present scientific justification for standardizing the use of anesthetics and analgesics, within a study, when modeling TBI in order to preserve study validity. Evidence for the interference of anesthetics and analgesics in the natural course of brain injury calls for consistent consideration of pain management regimens when conducting TBI research. Anesthetics administered at the time of or shortly after induction of brain injury can alter cognitive, motor, and histological outcomes following TBI. A consistent anesthesia protocol based on experimental objectives within each individual study is imperative when conducting TBI studies to control for the confounding effects of anesthesia on outcome parameters. Experimental studies that replicate the clinical condition are essential to gain further understanding and evaluate possible treatments for TBI. However, with animal models of TBI it is essential that investigators assure a uniform drug delivery protocol that minimizes confounding variables, while minimizing pain and suffering. PMID:23877609

Breakdown of local information processing may underlie isoflurane anesthesia effects.

PubMed

Wollstadt, Patricia; Sellers, Kristin K; Rudelt, Lucas; Priesemann, Viola; Hutt, Axel; Fröhlich, Flavio; Wibral, Michael

2017-06-01

The disruption of coupling between brain areas has been suggested as the mechanism underlying loss of consciousness in anesthesia. This hypothesis has been tested previously by measuring the information transfer between brain areas, and by taking reduced information transfer as a proxy for decoupling. Yet, information transfer is a function of the amount of information available in the information source-such that transfer decreases even for unchanged coupling when less source information is available. Therefore, we reconsidered past interpretations of reduced information transfer as a sign of decoupling, and asked whether impaired local information processing leads to a loss of information transfer. An important prediction of this alternative hypothesis is that changes in locally available information (signal entropy) should be at least as pronounced as changes in information transfer. We tested this prediction by recording local field potentials in two ferrets after administration of isoflurane in concentrations of 0.0%, 0.5%, and 1.0%. We found strong decreases in the source entropy under isoflurane in area V1 and the prefrontal cortex (PFC)-as predicted by our alternative hypothesis. The decrease in source entropy was stronger in PFC compared to V1. Information transfer between V1 and PFC was reduced bidirectionally, but with a stronger decrease from PFC to V1. This links the stronger decrease in information transfer to the stronger decrease in source entropy-suggesting reduced source entropy reduces information transfer. This conclusion fits the observation that the synaptic targets of isoflurane are located in local cortical circuits rather than on the synapses formed by interareal axonal projections. Thus, changes in information transfer under isoflurane seem to be a consequence of changes in local processing more than of decoupling between brain areas. We suggest that source entropy changes must be considered whenever interpreting changes in information transfer as decoupling.

Breakdown of local information processing may underlie isoflurane anesthesia effects

PubMed Central

Sellers, Kristin K.; Priesemann, Viola; Hutt, Axel

2017-01-01

The disruption of coupling between brain areas has been suggested as the mechanism underlying loss of consciousness in anesthesia. This hypothesis has been tested previously by measuring the information transfer between brain areas, and by taking reduced information transfer as a proxy for decoupling. Yet, information transfer is a function of the amount of information available in the information source—such that transfer decreases even for unchanged coupling when less source information is available. Therefore, we reconsidered past interpretations of reduced information transfer as a sign of decoupling, and asked whether impaired local information processing leads to a loss of information transfer. An important prediction of this alternative hypothesis is that changes in locally available information (signal entropy) should be at least as pronounced as changes in information transfer. We tested this prediction by recording local field potentials in two ferrets after administration of isoflurane in concentrations of 0.0%, 0.5%, and 1.0%. We found strong decreases in the source entropy under isoflurane in area V1 and the prefrontal cortex (PFC)—as predicted by our alternative hypothesis. The decrease in source entropy was stronger in PFC compared to V1. Information transfer between V1 and PFC was reduced bidirectionally, but with a stronger decrease from PFC to V1. This links the stronger decrease in information transfer to the stronger decrease in source entropy—suggesting reduced source entropy reduces information transfer. This conclusion fits the observation that the synaptic targets of isoflurane are located in local cortical circuits rather than on the synapses formed by interareal axonal projections. Thus, changes in information transfer under isoflurane seem to be a consequence of changes in local processing more than of decoupling between brain areas. We suggest that source entropy changes must be considered whenever interpreting changes in information transfer as decoupling. PMID:28570661

Photoacoustic microscopy of cerebral hemodynamic and oxygen-metabolic responses to anesthetics

NASA Astrophysics Data System (ADS)

Cao, Rui; Li, Jun; Ning, Bo; Sun, Naidi; Wang, Tianxiong; Zuo, Zhiyi; Hu, Song

2017-02-01

General anesthetics are known to have profound effects on cerebral hemodynamics and neuronal activities. However, it remains a challenge to directly assess anesthetics-induced hemodynamic and oxygen-metabolic changes from the true baseline under wakefulness at the microscopic level, due to the lack of an enabling technology for high-resolution functional imaging of the awake mouse brain. To address this challenge, we have developed head-restrained photoacoustic microscopy (PAM), which enables simultaneous imaging of the cerebrovascular anatomy, total concentration and oxygen saturation of hemoglobin (CHb and sO2), and blood flow in awake mice. From these hemodynamic measurements, two important metabolic parameters, oxygen extraction fraction (OEF) and the cerebral metabolic rate of oxygen (CMRO2), can be derived. Side-by-side comparison of the mouse brain under wakefulness and anesthesia revealed multifaceted cerebral responses to isoflurane, a volatile anesthetic widely used in preclinical research and clinical practice. Key observations include elevated cerebral blood flow (CBF) and reduced oxygen extraction and metabolism.

Health Benefits of Animal Research: The Dog as a Research Subject.

ERIC Educational Resources Information Center

Gay, William I.

1984-01-01

Discusses the role of dogs in research, considering their use in studies related to: behavior; aging; anesthesia; gastrointestinal surgery; the brain; organ transplants; radiobiology; trauma and shock; arterial diseases; hemophelia; ophthalmology; diabetes; nutrition; cancer; lupus; cyclic neutropenia; thyroiditis; hepatitis; skeletal system,…

Ventriculoperitoneal shunt

MedlinePlus

... cavities (ventricles) of the brain ( hydrocephalus ). Description This procedure is done in the operating room under general anesthesia. It takes about 1 1/2 hours. A tube (catheter) is passed from the cavities of the head to the ... is drained. The procedure is done as follows: An area of hair ...

Frailty Related to Anesthesia guided by the Index "bispectraL" (FRAIL) study: study protocol for a randomized controlled trial.

PubMed

Le Guen, Morgan; Herr, Marie; Bizard, Antoine; Bichon, Caroline; Boichut, Nathalie; Chazot, Thierry; Liu, Ngai; Ankri, Joel; Fischler, Marc

2017-03-16

Currently, patients older than 60 years of age represent 25% of the population and are at an increased risk during surgery. Therefore, reducing postoperative morbidity and mortality is a major concern in medical research and practice. Dependence on caregivers and cognitive impairment represent two major risk factors in the elderly, especially in frail patients after surgery under general anesthesia. In this context, continuous monitoring of the depth of anesthesia using a bispectral index (BIS) sensor may reduce the occurrence of impairments by gaining better control of the anesthetic depth. The first aim of this study is to compare manual versus automated administration of intravenous anesthetics with regard to 6-month functional decline in persons aged 70 years and older. The secondary objective includes an evaluation of the influence of the frail phenotype on self-sufficiency in elderly patients after general anesthesia. After receiving ethical committee approval and written consent, a complete preoperative assessment of physiological reserve and self-sufficiency will be performed on patients more than 70 years old who are scheduled for surgery under general anesthesia. This evaluation will determine the patient's frailty status in three categories: robust, pre-frail, and frail. Then, patients will be randomized into two groups: manual administration of anesthetics guided by BIS sensor (manual group) or automated administration (automated group) with recording of the anesthesia. A second examination will be scheduled after 6 months to assess changes in functional abilities, cognitive functions, and frailty status. A priori calculation of sample size gives a population of 430 patients to be included in this multicenter trial. This clinical study is designed to detect any postoperative complications and deaths related to the performance of the general anesthesia guided by the BIS sensor and the preoperative functional status of the elderly: robust, pre-frail, or frail. ClinicalTrials.gov, NCT02524327 . Registered on 10 August 2015.

Using animal models to evaluate the functional consequences of anesthesia during early neurodevelopment.

PubMed

Maloney, Susan E; Creeley, Catherine E; Hartman, Richard E; Yuede, Carla M; Zorumski, Charles F; Jevtovic-Todorovic, Vesna; Dikranian, Krikor; Noguchi, Kevin K; Farber, Nuri B; Wozniak, David F

2018-03-14

Fifteen years ago Olney and colleagues began using animal models to evaluate the effects of anesthetic and sedative agents (ASAs) on neurodevelopment. The results from ongoing studies indicate that, under certain conditions, exposure to these drugs during development induces an acute elevated apoptotic neurodegenerative response in the brain and long-term functional impairments. These animal models have played a significant role in bringing attention to the possible adverse effects of exposing the developing brain to ASAs when few concerns had been raised previously in the medical community. The apoptotic degenerative response resulting from neonatal exposure to ASAs has been replicated in many studies in both rodents and non-human primates, suggesting that a similar effect may occur in humans. In both rodents and non-human primates, significantly increased levels of apoptotic degeneration are often associated with functional impairments later in life. However, behavioral deficits following developmental ASA exposure have not been consistently reported even when significantly elevated levels of apoptotic degeneration have been documented in animal models. In the present work, we review this literature and propose a rodent model for assessing potential functional deficits following neonatal ASA exposure with special reference to experimental design and procedural issues. Our intent is to improve test sensitivity and replicability for detecting subtle behavioral effects, and thus enhance the translational significance of ASA models. Copyright © 2018 Elsevier Inc. All rights reserved.

Repeat Manipulation Under Anesthesia For Persistent Stiffness After Total Knee Arthroplasty Achieves Functional Range of Motion.

PubMed

Ferrel, Jason R; Davis, Richard L; Agha, Obiajulu A J C; Politi, Joel R

2015-05-01

Poor range of motion may decrease a patient's ability to participate in activities of daily living after total knee arthroplasty. Manipulation under anesthesia has been shown to improve range of motion; however, some patients have persistent stiffness even after manipulation. The goal of this study was to evaluate the outcomes and complications of patients who underwent a second manipulation under anesthesia for persistent stiffness after total knee arthroplasty. The review of surgical records of two joint arthroplasty surgeons identified 226 knees in 210 patients who underwent a manipulation under anesthesia for poor range of motion after total knee arthroplasty. Of these patients, 16 patients underwent a second manipulation under anesthesia. For patients undergoing two manipulations under anesthesia procedures, at latest follow up (mean 539 days), mean extension improved from 10.50° to 2.50° (p=0.001) and mean flexion improved from 87.50° to 112.69° (p=0.001) respectively. SF-12 scores were available for 12 of 16 knees with a mean score of 34.42. Two of 16 patients (12.5%) experienced a complication. Three of 16 (18.8%) patients who underwent a second manipulation required a revision arthroplasty procedure. In conclusion, a second manipulation under anesthesia can achieve functional range of motion that is sustained after total knee arthroplasty.

Influence of ketamine on regional brain glucose use

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, D.W.; Mans, A.M.; Biebuyck, J.F.

1988-08-01

The purpose of this study was to determine the effect of different doses of ketamine on cerebral function at the level of individual brain structures as reflected by glucose use. Rats received either 5 or 30 mg/kg ketamine intravenously as a loading dose, followed by an infusion to maintain a steady-state level of the drug. An additional group received 30 mg/kg as a single injection only, and was studied 20 min later, by which time they were recovering consciousness (withdrawal group). Regional brain energy metabolism was evaluated with (6-/sup 14/C)glucose and quantitative autoradiography during a 5-min experimental period. A subhypnotic,more » steady-state dose (5 mg/kg) of ketamine caused a stimulation of glucose use in most brain areas, with an average increase of 20%. At the larger steady-state dose (30 mg/kg, which is sufficient to cause anesthesia), there was no significant effect on most brain regions; some sensory nuclei were depressed (inferior colliculus, -29%; cerebellar dentate nucleus, -18%; vestibular nucleus, -16%), but glucose use in the ventral posterior hippocampus was increased by 33%. In contrast, during withdrawal from a 30-mg/kg bolus, there was a stimulation of glucose use throughout the brain (21-78%), at a time when plasma ketamine levels were similar to the levels in the 5 mg/kg group. At each steady-state dose, as well as during withdrawal, ketamine caused a notable stimulation of glucose use by the hippocampus.« less

Effect of laryngeal anesthesia on pulmonary function testing in normal subjects.

PubMed

Kuna, S T; Woodson, G E; Sant'Ambrogio, G

1988-03-01

Pulmonary function tests (PFT) were performed on 11 normal subjects before and after topical anesthesia of the larynx. The PFT consisted of flow volume loops and body box determinations of functional residual capacity and airway resistance, each performed in triplicate. After the first set of tests, cotton pledgets soaked in 4% lidocaine were held in the pyriform sinuses for 2 min to block the superior laryngeal nerves. In addition, 1.5 ml of 10% cocaine was dropped on the vocal cords via indirect laryngoscopy. PFT were repeated 5 min after anesthesia. Besides routine analysis of the flow volume loops, areas under the inspiratory (Area I) and expiratory (Area E) portions of the loops were calculated by planimetry. Area I, peak inspiratory flow (PIF), as well as forced inspiratory flow at 25, 50, and 75% forced vital capacity (FVC), decreased after anesthesia. Peak expiratory flow decreased after anesthesia, but Area E and forced expiratory flow at 25, 50, and 75% FVC were unchanged. This protocol also was performed in 12 normal subjects with isotonic saline being substituted for the lidocaine and cocaine. In this group, no significant differences were observed when flow volume loop parameters were compared before and after topical application of saline. In 5 spontaneously breathing anesthetized dogs, posterior cricoarytenoid muscle and afferent superior laryngeal nerve activity were recorded before and after laryngeal anesthesia performed with the same procedure used in the human subjects. Laryngeal anesthesia resulted in a substantial decrease or a complete disappearance of afferent SLN activity recorded during unobstructed and obstructed respiration. The data suggest that laryngeal receptors help modulate upper airway patency in man.

[Upper Age Limit in Outpatient Anesthesia: Opportunities and Risks].

PubMed

Hüppe, Tobias; Kneller, Nicole; Raddatz, Alexander

2018-05-01

Ambulatory surgery in elderly patients continues to increase - avoiding hospitalization and thus postoperative cognitive dysfunction in older patients being its major objectives. An upper age limit in outpatient anesthesia does not exist to date. However, functional rather than chronological age is crucial in patient selection. In consensus discussion, baseline functional status should be evaluated regularly - defined as everyday behaviors necessary to maintain daily life and encompassing areas of physical, cognitive, and social functioning. Moreover, frailty in elderly patients can be quantified objectively and is associated with increased perioperative morbidity in ambulatory general surgery. The decision for or against outpatient anesthesia therefore remains a case-by-case decision which should be discussed within a team. Georg Thieme Verlag KG Stuttgart · New York.

Sequential variation in brain functional magnetic resonance imaging after peripheral nerve injury: A rat study.

PubMed

Onishi, Okihiro; Ikoma, Kazuya; Oda, Ryo; Yamazaki, Tetsuro; Fujiwara, Hiroyoshi; Yamada, Shunji; Tanaka, Masaki; Kubo, Toshikazu

2018-04-23

Although treatment protocols are available, patients experience both acute neuropathic pain and chronic neuropathic pain, hyperalgesia, and allodynia after peripheral nerve injury. The purpose of this study was to identify the brain regions activated after peripheral nerve injury using functional magnetic resonance imaging (fMRI) sequentially and assess the relevance of the imaging results using histological findings. To model peripheral nerve injury in male Sprague-Dawley rats, the right sciatic nerve was crushed using an aneurysm clip, under general anesthesia. We used a 7.04T MRI system. T 2 * weighted image, coronal slice, repetition time, 7 ms; echo time, 3.3 ms; field of view, 30 mm × 30 mm; pixel matrix, 64 × 64 by zero-filling; slice thickness, 2 mm; numbers of slices, 9; numbers of average, 2; and flip angle, 8°. fMR images were acquired during electrical stimulation to the rat's foot sole; after 90 min, c-Fos immunohistochemical staining of the brain was performed in rats with induced peripheral nerve injury for 3, 6, and 9 weeks. Data were pre-processed by realignment in the Statistical Parametric Mapping 8 software. A General Linear Model first level analysis was used to obtain T-values. One week after the injury, significant changes were detected in the cingulate cortex, insular cortex, amygdala, and basal ganglia; at 6 weeks, the brain regions with significant changes in signal density were contracted; at 9 weeks, the amygdala and hippocampus showed activation. Histological findings of the rat brain supported the fMRI findings. We detected sequential activation in the rat brain using fMRI after sciatic nerve injury. Many brain regions were activated during the acute stage of peripheral nerve injury. Conversely, during the chronic stage, activation of the amygdala and hippocampus may be related to chronic-stage hyperalgesia, allodynia, and chronic neuropathic pain. Copyright © 2018 Elsevier B.V. All rights reserved.

Endocannabinoid signaling in hypothalamic circuits regulates arousal from general anesthesia in mice

PubMed Central

Zhong, Haixing; Tong, Li; Gu, Ning; Gao, Fang; Lu, Yacheng; Liu, Jingjing; Li, Xin; Bergeron, Richard; Pomeranz, Lisa E.; Wang, Feng; Luo, Chun-Xia; Ren, Yan; Wu, Sheng-Xi; Xie, Zhongcong; Xu, Lin; Li, Jinlian; Dong, Hailong; Xiong, Lize

2017-01-01

Consciousness can be defined by two major attributes: awareness of environment and self, and arousal, which reflects the level of awareness. The return of arousal after general anesthesia presents an experimental tool for probing the neural mechanisms that control consciousness. Here we have identified that systemic or intracerebral injection of the cannabinoid CB1 receptor (CB1R) antagonist AM281 into the dorsomedial nucleus of the hypothalamus (DMH) — but not the adjacent perifornical area (Pef) or the ventrolateral preoptic nucleus of the hypothalamus (VLPO) — accelerates arousal in mice recovering from general anesthesia. Anesthetics selectively activated endocannabinoid (eCB) signaling at DMH glutamatergic but not GABAergic synapses, leading to suppression of both glutamatergic DMH-Pef and GABAergic DMH-VLPO projections. Deletion of CB1R from widespread cerebral cortical or prefrontal cortical (PFC) glutamatergic neurons, including those innervating the DMH, mimicked the arousal-accelerating effects of AM281. In contrast, CB1R deletion from brain GABAergic neurons or hypothalamic glutamatergic neurons did not affect recovery time from anesthesia. Inactivation of PFC-DMH, DMH-VLPO, or DMH-Pef projections blocked AM281-accelerated arousal, whereas activation of these projections mimicked the effects of AM281. We propose that decreased eCB signaling at glutamatergic terminals of the PFC-DMH projection accelerates arousal from general anesthesia through enhancement of the excitatory DMH-Pef projection, the inhibitory DMH-VLPO projection, or both. PMID:28463228

How safe is deep sedation or general anesthesia while providing dental care?

PubMed

Bennett, Jeffrey D; Kramer, Kyle J; Bosack, Robert C

2015-09-01

Deep sedation and general anesthesia are administered daily in dental offices, most commonly by oral and maxillofacial surgeons and dentist anesthesiologists. The goal of deep sedation or general anesthesia is to establish a safe environment in which the patient is comfortable and cooperative. This requires meticulous care in which the practitioner balances the patient's depth of sedation and level of responsiveness while maintaining airway integrity, ventilation, and cardiovascular hemodynamics. Using the available data and informational reports, the authors estimate that the incidence of death and brain injury associated with deep sedation or general anesthesia administered by all dentists most likely exceeds 1 per month. Airway compromise is a significant contributing factor to anesthetic complications. The American Society of Anesthesiology closed claim analysis also concluded that human error contributed highly to anesthetic mishaps. The establishment of a patient safety database for anesthetic management in dentistry would allow for a more complete assessment of morbidity and mortality that could direct efforts to further increase safe anesthetic care. Deep sedation and general anesthesia can be safely administered in the dental office. Optimization of patient care requires appropriate patient selection, selection of appropriate anesthetic agents, utilization of appropriate monitoring, and a highly trained anesthetic team. Achieving a highly trained anesthetic team requires emergency management preparation that can foster decision making, leadership, communication, and task management. Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.

Isoflurane modulates neuronal excitability of the nucleus reticularis thalami in vitro.

PubMed

Joksovic, Pavle M; Todorovic, Slobodan M

2010-06-01

The thalamus has a key function in processing sensory information, sleep, and cognition. We examined the effects of a common volatile anesthetic, isoflurane, on modulation of neuronal excitability in reticular thalamic nucleus (nRT) in intact brain slices from immature rats. In current-clamp recordings, isoflurane (300-600 micromol/L) consistently depolarized membrane potential, decreased input resistance, and inhibited both rebound burst firing and tonic spike firing modes of nRT neurons. The isoflurane-induced depolarization persisted not only in the presence of tetrodotoxin, but after replacement of Ca(2+) with Ba(2+) ions in external solution; it was abolished by partial replacement of extracellular Na(+) ions with N-methyl-D-glucamine. In voltage-clamp recordings, we found that isoflurane slowed recovery from inactivation of T-type Ca(2+) current. Thus, at clinically relevant concentrations, isoflurane inhibits neuronal excitability of nRT neurons in developing brain via multiple ion channels. Inhibition of the neuronal excitability of thalamic cells may contribute to impairment of sensory information transfer in the thalamocortical network by general anesthetics. The findings may be important for understanding cellular mechanisms of anesthesia, such as loss of consciousness and potentially damaging consequences of general anesthetics on developing mammalian brains.

Parecoxib mitigates spatial memory impairment induced by sevoflurane anesthesia in aged rats.

PubMed

Gong, M; Chen, G; Zhang, X M; Xu, L H; Wang, H M; Yan, M

2012-05-01

Inflammation in brain plays a critical role in the pathogenesis of cognitive impairment. Anti-inflammatory therapy may thus constitute a novel approach for associated cognitive dysfunction. The present study investigated the effects of parecoxib in the prevention of cognitive impairments induced by sevoflurane in aged rats. Sixty-six aged rats were divided randomly into three groups: control group (n = 22, sham anesthesia), sevoflurane group (n = 22, received 2% sevoflurane for 5 h) and parecoxib group (n = 22, received intraperitoneal injections of 10 mg/kg parecoxib and then exposed to 2% sevoflurane for 5 h). Spatial learning performance was tested by Morris water maze. The expression of cyclooxygenase-2 protein and ultrastructure of synapse in hippocampus were measured. Sevoflurane anesthesia impaired the spatial learning and memory in aged rats. Compared with sevoflurane group, parecoxib group showed shorter escape latency and more number of crossings over the previous platform area. Furthermore, parecoxib treatment also significantly prevented the synaptic changes induced by sevoflurane. Parecoxib mitigates spatial memory impairment induced by sevoflurane anesthesia in aged rats. The synaptic morphometry change may be one of the mechanisms involved in learning and memory deficit. © 2012 The Authors. Acta Anaesthesiologica Scandinavica © 2012 The Acta Anaesthesiologica Scandinavica Foundation.

Acupuncture Effects on Cardiac Functions Measured by Cardiac Magnetic Resonance Imaging in a Feline Model

PubMed Central

Lin, Jen-Hsou; Shih, Chen-Haw; Kaphle, Krishna; Wu, Leang-Shin; Tseng, Weng-Yih; Chiu, Jen-Hwey; Lee, Tzu-chi

2010-01-01

The usefulness of acupuncture (AP) as a complementary and/or alternative therapy in animals is well established but more research is needed on its clinical efficacy relative to conventional therapy, and on the underlying mechanisms of the effects of AP. Cardiac magnetic resonance imaging (CMRI), an important tool in monitoring cardiovascular diseases, provides a reliable method to monitor the effects of AP on the cardiovascular system. This controlled experiment monitored the effect electro-acupuncture (EA) at bilateral acupoint Neiguan (PC6) on recovery time after ketamine/xylazine cocktail anesthesia in healthy cats. The CMRI data established the basic feline cardiac function index (CFI), including cardiac output and major vessel velocity. To evaluate the effect of EA on the functions of the autonomic nervous and cardiovascular systems, heart rate, respiration rate, electrocardiogram and pulse rate were also measured. Ketamine/xylazine cocktail anesthesia caused a transient hypertension in the cats; EA inhibited this anesthetic-induced hypertension and shortened the post-anesthesia recovery time. Our data support existing knowledge on the cardiovascular benefits of EA at PC6, and also provide strong evidence for the combination of anesthesia and EA to shorten post-anesthesia recovery time and counter the negative effects of anesthetics on cardiac physiology. PMID:18955311

Analysis of expert consultation referrals for anesthesia-related issues (December 2008-July 2010): KSA legislation committee report

PubMed Central

Lee, Kook Hyun; An, Tae-Hun; Choi, Jong Ho; Lim, Dong Gun; Lee, Yeong-Ju

2011-01-01

Background Since 2009, database construction of anesthesia-related adverse events has been initiated through the legislation committee of the Korean Society of Anesthesiologists (KSA), based on expert consultation referrals provided by police departments, civil courts, and criminal courts. Methods This study was a retrospective descriptive analysis of expert consultation referrals on surgical anesthesia-related cases between December 2008 and July 2010. Results During the given period, 46 surgical anesthesia-related cases were referred to the KSA legislation committee for expert consultation. Because six cases were excluded due to insufficient data, 40 cases were included in the final analysis. Of 40 cases, 29 (72.5%) resulted in death. Respiratory events were most common in both surviving/disabled and dead patients (36.4 vs. 51.7%, respectively; P > 0.05). Overall, respiratory depression due to the drugs used for monitored anesthesia care (MAC) was the most common specific mechanism (25%), in which all but one case (profound brain damage) resulted in death. In all of these cases, surgeons or physicians provided MAC without the help of anesthesiologists. Conclusions Overall, the most common damaging mechanism was related to respiratory depression due to sedatives or anesthetics used for MAC. Almost all MAC injury cases are believed to be preventable with the use of additional or better monitoring and an effective response to initial physiological derangement. Thus, it is essential to establish practical MAC guidelines and adhere to these guidelines strictly to reduce the occurrence of severe anesthesia-related adverse outcomes. PMID:21602976

Spinal anesthesia in children: A review

PubMed Central

Gupta, Anju; Saha, Usha

2014-01-01

Even after a vast safety record, the role of spinal anesthesia (SA) as a primary anesthetic technique in children remains contentious and is mainly limited to specialized pediatric centers. It is usually practiced on moribund former preterm infants (<60 weeks post-conception) to reduce the incidence of post-operative apnea when compared to general anesthesia (GA). However, there is ample literature to suggest its safety and efficacy for suitable procedures in older children as well. SA in children has many advantages as in adults with an added advantage of minimal cardio-respiratory disturbance. Recently, several reports from animal studies have raised serious concerns regarding the harmful effects of GA on young developing brain. This may further increase the utility of SA in children as it provides all components of balanced anesthesia technique. Also, SA can be an economical option for countries with finite resources. Limited duration of surgical anesthesia in children is one of the major deterrents for its widespread use in them. To overcome this, several additives like epinephrine, clonidine, fentanyl, morphine, neostigmine etc. have been used and found to be effective even in neonates. But, the developing spinal cord may also be vulnerable to drug-related toxicity, though this has not been systematically evaluated in children. So, adjuvants and drugs with widest therapeutic index should be preferred in children. Despite its widespread use, incidence of side-effects is low and permanent neurological sequalae have not been reported with SA. Literature yields encouraging results regarding its safety and efficacy. Technical skills and constant vigilance of experienced anesthesia providers is indispensable to achieve good results with this technique. PMID:24574586

Technical Aspects of Awake Craniotomy with Mapping for Brain Tumors in a Limited Resource Setting.

PubMed

Leal, Rafael Teixeira Magalhaes; Barcellos, Bruno Mendonça; Landeiro, Jose Alberto

2018-05-01

Brain tumor surgery near or within eloquent regions is increasingly common and is associated with a high risk of neurologic injury. Awake craniotomy with mapping has been shown to be a valid method to preserve neurologic function and increase the extent of resection. However, the technique used varies greatly among centers. Most count on professionals such as neuropsychologists, speech therapists, neurophysiologists, or neurologists to help in intraoperative patient evaluation. We describe our technique with the sole participation of neurosurgeons and anesthesiologists. A retrospective review of 19 patients who underwent awake craniotomies for brain tumors between January 2013 and February 2017 at a tertiary university hospital was performed. We sought to identify and describe the most critical stages involved in this surgery as well as show the complications associated with our technique. Preoperative preparation, positioning, anesthesia, brain mapping, resection, and management of seizures and pain were stages deemed relevant to the accomplishment of an awake craniotomy. Sixteen percent of the patients developed new postoperative deficit. Seizures occurred in 24%. None led to awake craniotomy failure. We provide a thorough description of the technique used in awake craniotomies with mapping used in our institution, where the intraoperative patient evaluation is carried out solely by neurosurgeons and anesthesiologists. The absence of other specialized personnel and equipment does not necessarily preclude successful mapping during awake craniotomy. We hope to provide helpful information for those who wish to offer function-guided tumor resection in their own centers. Copyright © 2018 Elsevier Inc. All rights reserved.

Anesthesia for euthanasia influences mRNA expression in healthy mice and after traumatic brain injury.

PubMed

Staib-Lasarzik, Irina; Kriege, Oliver; Timaru-Kast, Ralph; Pieter, Dana; Werner, Christian; Engelhard, Kristin; Thal, Serge C

2014-10-01

Tissue sampling for gene expression analysis is usually performed under general anesthesia. Anesthetics are known to modulate hemodynamics, receptor-mediated signaling cascades, and outcome parameters. The present study determined the influence of anesthetic paradigms typically used for euthanization and tissue sampling on cerebral mRNA expression in mice. Naïve mice and animals with acute traumatic brain injury induced by controlled cortical impact (CCI) were randomized to the following euthanasia protocols (n=10-11/group): no anesthesia (NA), 1 min of 4 vol% isoflurane in room air (ISO), 3 min of a combination of 5 mg/kg midazolam, 0.05 mg/kg fentanyl, and 0.5 mg/kg medetomidine intraperitoneally (COMB), or 3 min of 360 mg/kg chloral hydrate intraperitoneally (CH). mRNA expression of actin-1-related gene (Act1), FBJ murine osteosarcoma viral oncogene homolog B (FosB), tumor necrosis factor alpha (TNFα), heat shock protein beta-1 (HspB1), interleukin (IL)-6, tight junction protein 1 (ZO-1), IL-1ß, cyclophilin A, micro RNA 497 (miR497), and small cajal body-specific RNA 17 were determined by real-time polymerase chain reaction (PCR) in hippocampus samples. In naïve animals, Act1 expression was downregulated in the CH group compared with NA. FosB expression was downregulated in COMB and CH groups compared with NA. CCI reduced Act1 and FosB expression, whereas HspB1 and TNFα expression increased. After CCI, HspB1 expression was significantly higher in ISO, COMB, and CH groups, and TNFα expression was elevated in ISO and COMB groups. MiR497, IL-6, and IL-1ß were upregulated after CCI but not affected by anesthetics. Effects were independent of absolute mRNA copy numbers. The data demonstrate that a few minutes of anesthesia before tissue sampling are sufficient to induce immediate mRNA changes, which seem to predominate in the early-regulated gene cluster. Anesthesia-related effects on gene expression might explain limited reproduciblity of real-time PCR data between studies or research groups and should therefore be considered for quantitative PCR data.

The effects of exposure to general anesthesia in infancy on academic performance at age 12.

PubMed

Bong, Choon Looi; Allen, John Carson; Kim, Josephine Tan Swee

2013-12-01

Recent evidence from juvenile animal models has shown that exposure to anesthetic drugs above threshold doses during a critical neurodevelopmental window causes widespread neuronal apoptosis, resulting in irreversible brain damage and subsequent learning difficulties. The relevance of this to human infants having general anesthesia for minor surgery is unknown. In this pilot observational cohort study, we sought to determine whether children exposed to general anesthesia for minor surgery during infancy exhibited differences in academic achievement at age 12 years, as evidenced by (1) lower aggregate scores in the Singapore standardized Primary School Leaving Examination (PSLE) and (2) formally diagnosed learning disability, compared with children who were never exposed to anesthesia or sedation. We compared 100 full-term, apparently healthy children aged 12 years who were exposed to general anesthesia for minor surgery before age 1 at our institution with an age-matched cohort of 106 children who were never exposed to anesthesia or sedation. Parents of children completed a 20-minute telephone interview with questions regarding their children's medical history, school environment, and home environment. The difference in mean PSLE aggregate scores (3.0; 95% confidence interval [CI], -8.3 to 14.3) between exposed (197.0; 95% CI, 185.6-208.4) and control groups (194.0; 95% CI, 182.9-205.1) was not statistically significant (P = 0.603). The presence of formally diagnosed learning disability was 15% (15 of 100) in the exposed group compared with 3.77% (4 of 106) in the control group (P < 0.001). The odds ratio for a formal diagnosis of learning disability in those exposed to general anesthesia relative to controls was 4.5 (95% CI, 1.44-14.1). The odds of a formal diagnosis of learning disability by age 12 years in apparently healthy children exposed to general anesthesia for minor surgery during infancy were 4.5 times greater than their peers who had never been exposed to anesthesia. However, study precision was inadequate to detect a clinically relevant difference in PSLE scores.

The Efficacy and Safety of the Novel Peripheral Analgesic Isovaline as an Adjuvant to Propofol for General Anesthesia and Conscious Sedation: A Proof-of-Principle Study in Mice.

PubMed

Whitehead, Ryan A; Schwarz, Stephan K W; Asiri, Yahya I; Fung, Timothy; Puil, Ernest; MacLeod, Bernard A

2015-12-01

The combination of propofol and an opioid analgesic is widely used for procedural sedation, as well as total IV anesthesia. However, opioids produce respiratory depression, a primary cause of death due to these agents. We recently reported on the antinociceptive actions of isovaline, a small nonbiogenic amino acid that does not readily cross the blood-brain barrier and acts on peripheral γ-aminobutyric acid type B receptors. Here, we explored the possibility that isovaline may be an effective and safe alternative to opioids as an adjunct to propofol for producing anesthesia. With approval from our Animal Care Committee, we conducted an in vivo study in adult female CD-1 mice using Dixon's "up-and-down" method for dose assessment. Animals received intraperitoneal saline, propofol, isovaline, fentanyl, or coadministration of propofol with isovaline or fentanyl. We assessed hypnosis by a loss of righting reflex and immobility by an absence of motor response to tail clip application. General anesthesia was defined as the presence of both hypnosis and immobility. We assessed conscious sedation as a decrease in time on a rotarod. The maximal dose without respiratory rates of <4 per minute, apnea, or death was defined as the maximal tolerated dose. Either isovaline or fentanyl coadministered with propofol at its half-maximal effective dose (ED50) for hypnosis produced general anesthesia (isovaline ED50, 96 mg/kg [95% confidence interval {CI}, 88-124 mg/kg]; fentanyl ED50, 0.12 mg/kg [95% CI, 0.08-3.5 mg/kg]). Propofol produced hypnosis (ED50, 124 mg/kg [95% CI, 84-3520 mg/kg]) but did not block responses to tail clip application. Neither isovaline nor fentanyl produced hypnosis at doses which produced immobility (isovaline ED50, 350 mg/kg [95% CI, 286-1120 mg/kg]; fentanyl ED50, 0.35 mg/kg [95% CI, 0.23-0.51 mg/kg]). Isovaline at its analgesic ED50, coadministered with a subhypnotic dose of propofol (40 mg/kg), did not exacerbate propofol-induced deficits in rotarod performance. The median maximal tolerated dose of fentanyl coadministered with the hypnotic ED50 of propofol was 11 mg/kg (95% CI, 8-18 mg/kg). Isovaline at a maximal deliverable (soluble) dose of 5000 mg/kg produced no apparent respiratory depression or other adverse effects. The novel analgesic, isovaline, coadministered with propofol, produced general anesthesia and conscious sedation in mice. The margin of safety for propofol-isovaline was considerably higher than that for propofol-fentanyl. This study's results show that propofol-based sedation and general anesthesia can be effectively and safely produced by replacing the conventional opioid component with a brain-impermeant peripherally acting γ-aminobutyric acid type B receptor agonist. The results provide proof of the principle of combining a peripheral analgesic with a centrally acting hypnotic to produce general anesthesia. This principle suggests a novel approach to clinical general anesthesia and conscious sedation.

Capturing Pain in the Cortex during General Anesthesia: Near Infrared Spectroscopy Measures in Patients Undergoing Catheter Ablation of Arrhythmias

PubMed Central

Yücel, Meryem A.; Steele, Sarah C.; Alexander, Mark E.; Boas, David A.; Borsook, David; Becerra, Lino

2016-01-01

The predictability of pain makes surgery an ideal model for the study of pain and the development of strategies for analgesia and reduction of perioperative pain. As functional near-infrared spectroscopy reproduces the known functional magnetic resonance imaging activations in response to a painful stimulus, we evaluated the feasibility of functional near-infrared spectroscopy to measure cortical responses to noxious stimulation during general anesthesia. A multichannel continuous wave near-infrared imager was used to measure somatosensory and frontal cortical activation in patients undergoing catheter ablation of arrhythmias under general anesthesia. Anesthetic technique was standardized and intraoperative NIRS signals recorded continuously with markers placed in the data set for the timing and duration of each cardiac ablation event. Frontal cortical signals only were suitable for analysis in five of eight patients studied (mean age 14 ± 1 years, weight 66.7 ± 17.6 kg, 2 males). Thirty ablative lesions were recorded for the five patients. Radiofrequency or cryoablation was temporally associated with a hemodynamic response function in the frontal cortex characterized by a significant decrease in oxyhemoglobin concentration (paired t-test, p<0.05) with the nadir occurring in the period 4 to 6 seconds after application of the ablative lesion. Cortical signals produced by catheter ablation of arrhythmias in patients under general anesthesia mirrored those seen with noxious stimulation in awake, healthy volunteers, during sedation for colonoscopy, and functional Magnetic Resonance Imaging activations in response to pain. This study demonstrates the feasibility and potential utility of functional near-infrared spectroscopy as an objective measure of cortical activation under general anesthesia. PMID:27415436

Capturing Pain in the Cortex during General Anesthesia: Near Infrared Spectroscopy Measures in Patients Undergoing Catheter Ablation of Arrhythmias.

PubMed

Kussman, Barry D; Aasted, Christopher M; Yücel, Meryem A; Steele, Sarah C; Alexander, Mark E; Boas, David A; Borsook, David; Becerra, Lino

2016-01-01

The predictability of pain makes surgery an ideal model for the study of pain and the development of strategies for analgesia and reduction of perioperative pain. As functional near-infrared spectroscopy reproduces the known functional magnetic resonance imaging activations in response to a painful stimulus, we evaluated the feasibility of functional near-infrared spectroscopy to measure cortical responses to noxious stimulation during general anesthesia. A multichannel continuous wave near-infrared imager was used to measure somatosensory and frontal cortical activation in patients undergoing catheter ablation of arrhythmias under general anesthesia. Anesthetic technique was standardized and intraoperative NIRS signals recorded continuously with markers placed in the data set for the timing and duration of each cardiac ablation event. Frontal cortical signals only were suitable for analysis in five of eight patients studied (mean age 14 ± 1 years, weight 66.7 ± 17.6 kg, 2 males). Thirty ablative lesions were recorded for the five patients. Radiofrequency or cryoablation was temporally associated with a hemodynamic response function in the frontal cortex characterized by a significant decrease in oxyhemoglobin concentration (paired t-test, p<0.05) with the nadir occurring in the period 4 to 6 seconds after application of the ablative lesion. Cortical signals produced by catheter ablation of arrhythmias in patients under general anesthesia mirrored those seen with noxious stimulation in awake, healthy volunteers, during sedation for colonoscopy, and functional Magnetic Resonance Imaging activations in response to pain. This study demonstrates the feasibility and potential utility of functional near-infrared spectroscopy as an objective measure of cortical activation under general anesthesia.

Functional impairment of the auditory pathway after perinatal asphyxia and the short-term effect of perinatal propofol anesthesia in lambs.

PubMed

Smit, Adriana L; Seehase, Matthias; Stokroos, Robert J; Jellema, Reint K; Felipe, Lilian; Chenault, Michelene N; Anteunis, Lucien J C; Kremer, Bernd; Kramer, Boris W

2013-07-01

Sensorineural hearing loss (SNHL) is a common feature in the postasphyxial syndrome in newborns. Several anesthetic drugs have been proposed to attenuate secondary neuronal injury elicited by hypoxia-ischemia. We hypothesized that propofol anesthesia reduces auditory impairment after perinatal asphyxia in comparison with isoflurane. Twenty-three pregnant ewes were randomized to propofol or isoflurane anesthesia and sedation. The lambs underwent in utero umbilical cord occlusion (isoflurane n = 5; propofol n = 7) and were compared with sham-treated animals (isoflurane n = 5; propofol n = 6) at a gestational age of 133 d. For 8 h after delivery by cesarean section, repeated auditory brainstem responses (ABRs) were recorded to obtain hearing thresholds, peak amplitudes, latencies, and interpeak latencies. Significantly elevated mean thresholds, diminished amplitudes, and elevated latencies were observed in the asphyxia group relative to the control group through the observation period. Comparison of anesthetic treatment in the asphyxia group revealed a significantly lower elevation in threshold and less impairment in the ABR amplitudes and latencies during propofol anesthesia as compared with isoflurane anesthesia. Our results support the hypothesis that anesthesia with propofol has a preventive effect on the functional changes to the auditory pathway in the event of perinatal asphyxia.

“Awake” intraoperative functional MRI (ai-fMRI) for mapping the eloquent cortex: Is it possible in awake craniotomy?☆

PubMed Central

Lu, Jun-Feng; Zhang, Han; Wu, Jin-Song; Yao, Cheng-Jun; Zhuang, Dong-Xiao; Qiu, Tian-Ming; Jia, Wen-Bin; Mao, Ying; Zhou, Liang-Fu

2012-01-01

As a promising noninvasive imaging technique, functional MRI (fMRI) has been extensively adopted as a functional localization procedure for surgical planning. However, the information provided by preoperative fMRI (pre-fMRI) is hampered by the brain deformation that is secondary to surgical procedures. Therefore, intraoperative fMRI (i-fMRI) becomes a potential alternative that can compensate for brain shifts by updating the functional localization information during craniotomy. However, previous i-fMRI studies required that patients be under general anesthesia, preventing the wider application of such a technique as the patients cannot perform tasks unless they are awake. In this study, we propose a new technique that combines awake surgery and i-fMRI, named “awake” i-fMRI (ai-fMRI). We introduced ai-fMRI to the real-time localization of sensorimotor areas during awake craniotomy in seven patients. The results showed that ai-fMRI could successfully detect activations in the bilateral primary sensorimotor areas and supplementary motor areas for all patients, indicating the feasibility of this technique in eloquent area localization. The reliability of ai-fMRI was further validated using intraoperative stimulation mapping (ISM) in two of the seven patients. Comparisons between the pre-fMRI-derived localization result and the ai-fMRI derived result showed that the former was subject to a heavy brain shift and led to incorrect localization, while the latter solved that problem. Additionally, the approaches for the acquisition and processing of the ai-fMRI data were fully illustrated and described. Some practical issues on employing ai-fMRI in awake craniotomy were systemically discussed, and guidelines were provided. PMID:24179766

Mass-spectrometric monitoring of the intravenous anesthetic concentration in the breathing circuit of an anesthesia machine

NASA Astrophysics Data System (ADS)

Elizarov, A. Yu.; Levshankov, A. I.

2011-04-01

Interaction between inhalational anesthetic sevoflurane and an absorber of CO2 (soda lime) in the breathing circuit of an anesthesia machine during low-flow anesthesia (0.5 l of a fresh gaseous mixture per minute) is studied with the mass-spectrometric method. Monitoring data for the concentration of sevoflurane and three toxic products of sevoflurane decompositions (substances A, B, and C) during anesthesia in the inspiration-expiration regime are presented. The highest concentration of substance A is found to be 65 ppm. The biochemical blood analysis before and after anesthesia shows that nephropathy is related to the function of liver toxicity. It is found that inhalational anesthetic sevoflurane influences the concentration of intravenous hypnotic propofol in blood.

Use of a rapid brain-sampling technique in a physiologic preparation: effects of morphine, ketamine, and halothane on tissue energy intermediates.

PubMed

Dedrick, D F; Sherer, Y D; Biebuyck, J F

1975-06-01

A new method of rapid sampling of brain tissue, "freeze-blowing," has been used to compare the neurochemistry of the brain during anesthesia with that in the awake state. The method avoids anoxia associated with the sampling process. Physiologic variables, including body temperature, blood-gas tensions and blood pressure, were carefully monitored and controlled in the experimental animals. None of the agents tested (halothane, morphine, and ketamine) reduced the brain tissue high-energy phosphate reserved. All three drugs doubled glucose levels. Morphine lowered both lactate and the lactate/pyruvate ratio. Uniformly, the three anesthetic agents led to twofold increases of brain cyclic 3'-5' adenosine monophosphate concentrations. These changes suggest a possible role for cyclic nucleotides in central neurotransmission.

Ophthalmologic complications after administration of local anesthesia in dentistry: a systematic review.

PubMed

Alamanos, Christos; Raab, Philipp; Gamulescu, Andreea; Behr, Michael

2016-03-01

The aim of this review was to investigate the association between the occurrence of ocular adverse events and dental local anesthesia, the most plausible anatomic mechanisms, and the measures that offer patients a restitutio ad integrum. This systematic review adopted a structured protocol to access available publications and followed the PRISMA statement. Eighty-nine cases of patients experiencing ocular adverse events after administration of dental local anesthesia have been reported in the literature. Most of the complications manifested as double vision. Only 8% of the complications caused permanent functional damage, either as vision deficit or anisocoria. Complete permanent blindness was not reported. Ocular complications as a result of dental local anesthesia may be seen as rare occurrences with usually low intensity. However, visual function may become permanently impaired and serious medical conditions may obscure ocular dysfunction. Copyright © 2016. Published by Elsevier Inc.

The effect of anesthetization and urinary bladder catheterization on renal function of rainbow trout

USGS Publications Warehouse

Hunn, J.B.; Willford, W.A.

1970-01-01

1. Rainbow trout were anesthetized with MS-222 (Sandoz) or methylpentynol and catheterized. Urine was collected at selected intervals up to 48 hr. 2. Effects of MS-222 anesthesia on urine flow and composition were isolated from the stress of catheterization by re-anesthetizing the fish 18 to 20 hr post catheterization. 3. Urine output patterns were similar following MS-222 or methylpentynol anesthesia and catheterization. Highest urine flows were measured 4 to 8 hr post treatment. The highest urine output after re-anesthetization with MS-222 was observed 2 to 4 hr post-anesthesia. 4. Highest concentrations of Na2+, K+, Ca2+, Cl- and inorganic PO4 in the urine were measured in the first 2 hr after anesthesia and catheterization. 5. Flow rates and chemical composition of urine indicate that "normal" renal function is re-established 12 to 24 hr post-treatment.

Site specific effects of anosmia and cloacal gland anesthesia on Fos expression induced in male quail brain by sexual behavior

PubMed Central

Taziaux, Mélanie; Keller, Matthieu; Ball, Gregory F.; Balthazart, Jacques

2008-01-01

In rats, expression of the immediate early gene, c-fos observed in the brain following male copulatory behavior relates mostly to the detection of olfactory information originating from the female and to somatosensory feedback from the penis. However, quail, like most birds, are generally considered to have a relatively poorly developed sense of smell. Furthermore, quail have no intromittent organ (e.g., penis). It is therefore intriguing that expression of male copulatory behavior induces in quail and rats a similar pattern of c-fos expression in the medial preoptic area (mPOA), bed nucleus of the stria terminalis (BSTM) and parts of the amygdala. We analyzed here by immunocytochemistry Fos expression in the mPOA/BSTM/amygdala of male quail that had been allowed to copulate with a female during standardized tests. Before these tests, some of the males had either their nostrils plugged, or their cloacal area anesthetized, or both. A control group was not exposed to females. These manipulations did not affect frequencies of male sexual behavior and all birds exposed to a female copulated normally. In the mPOA, the increased Fos expression induced by copulation was not affected by the cloacal gland anesthesia but was markedly reduced in subjects deprived of olfactory input. Both manipulations affected copulation-induced Fos expression in the BSTM. No change in Fos expression was observed in the amygdala. Thus immediate early gene expression in the mPOA and BSTM of quail is modulated at least in part by olfactory cues and/or somatosensory stimuli originating from the cloacal gland. Future work should specify the nature of these stimuli and their function in the expression of avian male sexual behavior. PMID:18638505

Comparison of analgesic efficacy of preoperative or postoperative carprofen with or without preincisional mepivacaine epidural anesthesia in canine pelvic or femoral fracture repair.

PubMed

Bergmann, Hannes M; Nolte, Ingo; Kramer, Sabine

2007-10-01

To compare analgesic efficacy of preoperative versus postoperative administration of carprofen and to determine, if preincisional mepivacaine epidural anesthesia improves postoperative analgesia in dogs treated with carprofen. Blind, randomized clinical study. Dogs with femoral (n=18) or pelvic (27) fractures. Dogs were grouped by restricted randomization into 4 groups: group 1 = carprofen (4 mg/kg subcutaneously) immediately before induction of anesthesia, no epidural anesthesia; group 2 = carprofen immediately after extubation, no epidural anesthesia; group 3 = carprofen immediately before induction, mepivacaine epidural block 15 minutes before surgical incision; and group 4 = mepivacaine epidural block 15 minutes before surgical incision, carprofen after extubation. All dogs were administered carprofen (4 mg/kg, subcutaneously, once daily) for 4 days after surgery. Physiologic variables, nociceptive threshold, lameness score, pain, and sedation (numerical rating scale [NRS], visual analog scale [VAS]), plasma glucose and cortisol concentration, renal function, and hemostatic variables were measured preoperatively and at various times after surgery. Dogs with VAS pain scores >30 were administered rescue analgesia. Group 3 and 4 dogs had significantly lower pain scores and amount of rescue analgesia compared with groups 1 and 2. VAS and NRS pain scores were not significantly different among groups 1 and 2 or among groups 3 and 4. There was no treatment effect on renal function and hemostatic variables. Preoperative carprofen combined with mepivacaine epidural anesthesia had superior postoperative analgesia compared with preoperative carprofen alone. When preoperative epidural anesthesia was performed, preoperative administration of carprofen did not improve postoperative analgesia compared with postoperative administration of carprofen. Preoperative administration of systemic opioid agonists in combination with regional anesthesia and postoperative administration of carprofen provides safe and effective pain relieve in canine fracture repair.

Percolation Model of Sensory Transmission and Loss of Consciousness Under General Anesthesia

NASA Astrophysics Data System (ADS)

Zhou, David W.; Mowrey, David D.; Tang, Pei; Xu, Yan

2015-09-01

Neurons communicate with each other dynamically; how such communications lead to consciousness remains unclear. Here, we present a theoretical model to understand the dynamic nature of sensory activity and information integration in a hierarchical network, in which edges are stochastically defined by a single parameter p representing the percolation probability of information transmission. We validate the model by comparing the transmitted and original signal distributions, and we show that a basic version of this model can reproduce key spectral features clinically observed in electroencephalographic recordings of transitions from conscious to unconscious brain activities during general anesthesia. As p decreases, a steep divergence of the transmitted signal from the original was observed, along with a loss of signal synchrony and a sharp increase in information entropy in a critical manner; this resembles the precipitous loss of consciousness during anesthesia. The model offers mechanistic insights into the emergence of information integration from a stochastic process, laying the foundation for understanding the origin of cognition.

Sevoflurane-induced down-regulation of hippocampal oxytocin and arginine vasopressin impairs juvenile social behavioral abilities.

PubMed

Zhou, Zhi-Bin; Yang, Xiao-Yu; Yuan, Bao-Long; Niu, Li-Jun; Zhou, Xue; Huang, Wen-Qi; Feng, Xia; Zhou, Li-Hua

2015-05-01

Cumulative evidence indicates that early childhood anesthesia can alter a child's future behavioral performance. Animal researchers have found that sevoflurane, the most commonly used anesthetic for children, can produce damage in the neonatal brains of rodents. To further investigate this phenomenon, we focused on the influence of sevoflurane anesthesia on the development of juvenile social behavioral abilities and the pro-social proteins oxytocin (OT) and arginine vasopressin (AVP) in the neonatal hippocampus. A single 6-h sevoflurane exposure for postnatal day 5 mice resulted in decreased OT and AVP messenger RNA (mRNA) and protein levels in the hippocampus. OT and AVP proteins became sparsely distributed in the dorsal hippocampus after the exposure to sevoflurane. Compared with the air-treated group, mice in the sevoflurane-treated group showed signs of impairment in social recognition memory formation and social discrimination ability. Sevoflurane anesthesia reduces OT and AVP activities in the neonatal hippocampus and impairs social recognition memory formation and social discrimination ability in juvenile mice.

Use of the Draeger Apollo to Deliver Bilevel Positive Pressure Ventilation During Awake Frontal Craniotomy for a Patient with Severe Chronic Obstructive Pulmonary Disease.

PubMed

Lee, Susie So-Hyun; Berman, Mitchell F

2015-12-01

In this case report, we describe the use of the Draeger Apollo anesthesia machine to deliver bilevel positive airway pressure (BiPAP) to a patient with severe chronic obstructive pulmonary disease and a history of lung resection undergoing frontal craniotomy for the removal of a brain tumor under moderate to deep sedation. BiPAP in the perioperative period has been described for purposes of preoxygenation and postextubation recruitment. Although its utility as a mode of ventilation during moderate to deep sedation has been demonstrated, it has not come into widespread use. We describe the intraoperative use of pressure support mode on the anesthesia machine to deliver noninvasive positive pressure ventilation through a standard anesthesia mask. Given its ease of access and effectiveness, it is our belief that intraoperative BiPAP may reduce hypoxemia and/or hypercarbia in patients with chronic obstructive pulmonary disease and obstructive sleep apnea undergoing moderate to deep sedation.

Mechanics and Morphology of Silk Drawn from Anesthetized Spiders

NASA Astrophysics Data System (ADS)

Madsen, B.; Vollrath, F.

CO2 and N2 anesthetized Nephila spiders produced dragline silk with mechanical properties that differed from control silk as a function of time under anesthesia. Silk from CO2 spiders had a significantly lower breaking strain and breaking energy, significantly higher initial modulus, and marginally lower breaking stress. At the onset of anesthesia the silk diameter became highly variable. During deep anesthesia silk either became thinner or retained cross-section but fibrillated.

The uncomfortable reality … We simply do not know if general anesthesia negatively impacts the neurocognitive development of our small children.

PubMed

Mann, Glenn E; Kahana, Madelyn

2015-09-01

Annually in the United States more than one million children under the age of 5 years are exposed to anesthetics for therapeutic and diagnostic procedures. Pre-clinical data in animal models has consistently shown that anesthetic exposure to the developing brain results in long-term cognitive deficits. Current clinical data addressing the safety of these pharmaceutical agents on the developing human brain is limited. Recently, there has been an enormous amount of attention directed at this potential public health issue in both pre-clinical investigations and ongoing human research. A number of these studies should add to our understanding about the impact anesthetic exposure will have on the developing human brain. Until then, there is little data that absolutely reassures clinicians and parents that the pharmaceutical agents used are indeed safe for our children. The uncomfortable reality is that despite the fact that there are more than one million children younger than 5 years old who receive general anesthesia in the United States annually, and thousands more who are deeply sedated for imaging and diagnostic studies or as a necessary adjunct to care in the intensive care unit, there is little data that assures clinicians and parents that the pharmaceutical agents used are indeed safe for the developing brain. That said, there are no convincing human data to suggest that they are not. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Burst suppression probability algorithms: state-space methods for tracking EEG burst suppression

NASA Astrophysics Data System (ADS)

Chemali, Jessica; Ching, ShiNung; Purdon, Patrick L.; Solt, Ken; Brown, Emery N.

2013-10-01

Objective. Burst suppression is an electroencephalogram pattern in which bursts of electrical activity alternate with an isoelectric state. This pattern is commonly seen in states of severely reduced brain activity such as profound general anesthesia, anoxic brain injuries, hypothermia and certain developmental disorders. Devising accurate, reliable ways to quantify burst suppression is an important clinical and research problem. Although thresholding and segmentation algorithms readily identify burst suppression periods, analysis algorithms require long intervals of data to characterize burst suppression at a given time and provide no framework for statistical inference. Approach. We introduce the concept of the burst suppression probability (BSP) to define the brain's instantaneous propensity of being in the suppressed state. To conduct dynamic analyses of burst suppression we propose a state-space model in which the observation process is a binomial model and the state equation is a Gaussian random walk. We estimate the model using an approximate expectation maximization algorithm and illustrate its application in the analysis of rodent burst suppression recordings under general anesthesia and a patient during induction of controlled hypothermia. Main result. The BSP algorithms track burst suppression on a second-to-second time scale, and make possible formal statistical comparisons of burst suppression at different times. Significance. The state-space approach suggests a principled and informative way to analyze burst suppression that can be used to monitor, and eventually to control, the brain states of patients in the operating room and in the intensive care unit.

General anesthetics and cytotoxicity: possible implications for brain health.

PubMed

Armstrong, Ryden; Xu, Fenglian; Arora, Anish; Rasic, Nivez; Syed, Naweed I

2017-04-01

The search for agents that bring about faster induction and quicker recovery in the operating room have yielded numerous anesthetics whose mechanisms of action and potential toxic side effects remain unknown, especially in the young and aging brain. Taking advantage of our clinical and basic science expertise, here we subject the reader to an interesting perspective vis-à-vis the current applications of general anesthetics, and present evidence for their neurotoxic effects on the developing and elderly brains. Recent studies have called into question the safety of general anesthetics, especially with regards to potentially significant detrimental impacts on the developing brains of young children, and cognitive decline in the elderly - often following multiple episodes of anesthesia. Despite accumulating evidence from animal studies demonstrating that general anesthesia leads to neurodegeneration and cognitive impairment, to date a clear consensus on the impact of anesthetics in humans remains elusive. Because a direct impact of anesthetics on human neuronal networks is often difficult to deduce experimentally, most laboratories have resorted to animal models - albeit with limited success in translating these findings back to the clinic. Moreover, the precise mechanisms that lead to potential cognitive, learning, and memory decline in young and elderly patients also remain to be fully defined. This review will focus primarily on the cytotoxic effects of anesthetics, and offer some practical resolutions that may attenuate their long-term harm. An urgent need for studies on animal models and an increased focus on highly controlled prospective epidemiological studies is also reinforced.

Anesthesia Care Capacity at Health Facilities in 22 Low- and Middle-Income Countries.

PubMed

Hadler, Rachel A; Chawla, Sagar; Stewart, Barclay T; McCunn, Maureen C; Kushner, Adam L

2016-05-01

Globally, an estimated 2 billion people lack access to surgical and anesthesia care. We sought to pool results of anesthesia care capacity assessments in low- and middle-income countries (LMICs) to identify patterns of deficits and provide useful targets for advocacy and intervention. A systematic review of PubMed, Cochrane Database of Systematic Reviews, and Google Scholar identified reports that documented anesthesia care capacity from LMICs. When multiple assessments from one country were identified, only the study with the most facilities assessed was included. Patterns of availability or deficit were described. We identified 22 LMICs (15 low- and 8 middle-income countries) with anesthesia care capacity assessments (614 facilities assessed). Anesthesia care resources were often unavailable, including relatively low-cost ones (e.g., oxygen and airway supplies). Capacity varied markedly between and within countries, regardless of the national income. The availability of fundamental resources for safe anesthesia, such as airway supplies and functional pulse oximeters, was often not reported (72 and 36 % of hospitals assessed, respectively). Anesthesia machines and the capability to perform general anesthesia were unavailable in 43 % (132/307 hospitals) and 56 % (202/361) of hospitals, respectively. We identified a pattern of critical deficiencies in anesthesia care capacity in LMICs, including some low-cost, high-value added resources. The global health community should advocate for improvements in anesthesia care capacity and the potential benefits of doing so to health system planners. In addition, better quality data on anesthesia care capacity can improve advocacy, as well as the monitoring and evaluation of changes over time and the impact of capacity improvement interventions.

RT-06GAMMA KNIFE SURGERY AFTER NAVIGATION-GUIDED ASPIRATION FOR CYSTIC METASTATIC BRAIN TUMORS

PubMed Central

Chiba, Yasuyoshi; Mori, Kanji; Toyota, Shingo; Kumagai, Tetsuya; Yamamoto, Shota; Sugano, Hirofumi; Taki, Takuyu

2014-01-01

Metastatic brain tumors over 3 cm in diameter (volume of 14.1ml) are generally considered poor candidates for Gamma Knife surgery (GKS). We retrospectively assessed the method and efficacy of GKS for large cystic metastatic brain tumors after navigation-guided aspiration under local anesthesia. From September 2007 to April 2014, 38 cystic metastatic brain tumors in 32 patients (12 males, 20 females; mean age, 63.2 years) were treated at Kansai Rosai Hospital. The patients were performed navigation-guided cyst aspiration under local anesthesia, then at the day or the next day, were performed GKS and usually discharged on the day. The methods for preventing of leptomeningeal dissemination are following: 1) puncture from the place whose cerebral thickness is 1 cm or more; 2) avoidance of Ommaya reservoir implantation; and 3) placement of absorbable gelatin sponge to the tap tract. Tumor volume, including the cystic component, decreased from 25.4 ml (range 8.7-84.7 ml) to 11.4 ml (range 2.9-36.7 ml) following aspiration; the volume reduction was approximately 51.6%. Follow-up periods in the study population ranged from 0 to 24 months (median 3.5 months). The overall median survival was 6.7 months. There was no leptomeningeal dissemination related to the aspiration. One patient experienced radiation necrosis after GKS, one patient experienced re-aspiration by failure of aspiration, and two patients experienced surgical resections and one patient experienced re-aspiration by cyst regrowth after GKS. Long-term hospitalization is not desirable for the patients with brain metastases. In japan, Long-term hospitalization is required for surgical resection or whole brain radiation therapy, but only two days hospitalization is required for GKS after navigation-guided aspiration at our hospital. This GKS after navigation-guided aspiration is more effective and less invasive than surgical resection or whole brain radiation therapy.

Statistical framework and noise sensitivity of the amplitude radial correlation contrast method.

PubMed

Kipervaser, Zeev Gideon; Pelled, Galit; Goelman, Gadi

2007-09-01

A statistical framework for the amplitude radial correlation contrast (RCC) method, which integrates a conventional pixel threshold approach with cluster-size statistics, is presented. The RCC method uses functional MRI (fMRI) data to group neighboring voxels in terms of their degree of temporal cross correlation and compares coherences in different brain states (e.g., stimulation OFF vs. ON). By defining the RCC correlation map as the difference between two RCC images, the map distribution of two OFF states is shown to be normal, enabling the definition of the pixel cutoff. The empirical cluster-size null distribution obtained after the application of the pixel cutoff is used to define a cluster-size cutoff that allows 5% false positives. Assuming that the fMRI signal equals the task-induced response plus noise, an analytical expression of amplitude-RCC dependency on noise is obtained and used to define the pixel threshold. In vivo and ex vivo data obtained during rat forepaw electric stimulation are used to fine-tune this threshold. Calculating the spatial coherences within in vivo and ex vivo images shows enhanced coherence in the in vivo data, but no dependency on the anesthesia method, magnetic field strength, or depth of anesthesia, strengthening the generality of the proposed cutoffs. Copyright (c) 2007 Wiley-Liss, Inc.

Cerebral oxygenation in patients undergoing shoulder surgery in beach chair position: comparing general to regional anesthesia and the impact on neurobehavioral outcome.

PubMed

Aguirre, J; Borgeat, A; Trachsel, T; Cobo Del Prado, I; De Andrés, J; Bühler, P

2014-02-01

Ischemic brain damage has been reported in healthy patients after beach chair position for surgery due to cerebral hypoperfusion. Near-infrared spectroscopy has been described as a non-invasive, continuous method to monitor cerebral oxygen saturation. However, its impact on neurobehavioral outcome comparing different anesthesia regimens has been poorly described. In this prospective, assessor-blinded study, 90 patients undergoing shoulder surgery in beach chair position following general (G-group, n=45) or regional anesthesia (R-group; n=45) were enrolled to assess the prevalence of cerebral desaturation events comparing anesthesia regimens and their impact on neurobehavioral and neurological outcome. Anesthesiologists were blinded to regional cerebral oxygen saturation values. Baseline data assessed the day before surgery included neurological and neurobehavioral tests, which were repeated the day after surgery. The baseline data for regional cerebral oxygen saturation/bispectral index and invasive blood pressure both at heart and auditory meatus levels were taken prior to anesthesia, 5 min after induction of anesthesia, 5 min after beach chair positioning, after skin incision and thereafter all 20 min until discharge. Patients in the R-group showed significantly less cerebral desaturation events (p<0.001), drops in regional cerebral oxygen saturation values (p<0.001), significantly better neurobehavioral test results the day after surgery (p<0.001) and showed a greater hemodynamic stability in the beach chair position compared to patients in the G-group. The incidence of regional cerebral oxygen desaturations seems to influence the neurobehavioral outcome. Regional anesthesia offers more stable cardiovascular conditions for shoulder surgery in beach chair position influencing neurobehavioral test results at 24h. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Brain Monitoring with Electroencephalography and the Electroencephalogram-Derived Bispectral Index During Cardiac Surgery

PubMed Central

Kertai, Miklos D.; Whitlock, Elizabeth L.; Avidan, Michael S.

2011-01-01

Cardiac surgery presents particular challenges for the anesthesiologist. In addition to standard and advanced monitors typically used during cardiac surgery, anesthesiologists may consider monitoring the brain with raw or processed electroencephalography (EEG). There is strong evidence that a protocol incorporating the processed EEG Bispectral Index (BIS) decreases the incidence intraoperative awareness compared with standard practice. However there is conflicting evidence that incorporating the BIS into cardiac anesthesia practice improves “fast-tracking,” decreases anesthetic drug use, or detects cerebral ischemia. Recent research, including many cardiac surgical patients, shows that a protocol based on BIS monitoring is not superior to a protocol based on end tidal anesthetic concentration monitoring in preventing awareness. There has been a resurgence of interest in the anesthesia literature in limited montage EEG monitoring, including nonproprietary processed indices. This has been accompanied by research showing that with structured training, anesthesiologists can glean useful information from the raw EEG trace. In this review, we discuss both the hypothesized benefits and limitations of BIS and frontal channel EEG monitoring in the cardiac surgical population. PMID:22253267

Effects of ellagic acid pretreatment on renal functions disturbances induced by global cerebral ischemic-reperfusion in rat.

PubMed

Nejad, Khojasteh Hoseiny; Gharib-Naseri, Mohammad Kazem; Sarkaki, Alireza; Dianat, Mahin; Badavi, Mohammad; Farbood, Yaghoub

2017-01-01

Global cerebral ischemia-reperfusion (GCIR) causes disturbances in brain functions as well as other organs such as kidney. Our aim was to evaluate the protective effects of ellagic acid (EA) on certain renal disfunction after GCIR. Adult male Wistar rats (n=32, 250-300 g) were used. GCIR was induced by bilateral vertebral and common carotid arteries occlusion (4-VO). Animal groups were: 1) received DMSO/saline (10%) as solvent of EA, 2) solvent + GCIR, 3) EA + GCIR, and 4) EA. Under anesthesia with ketamine/xylazine, GCIR was induced (20 and 30 min respectively) in related groups. EA (100 mg/kg, dissolved in DMSO/saline (10%) or solvent was administered (1.5 ml/kg) orally for 10 consecutive days to the related groups. EEG was recorded from NTS in GCIR treated groups. Our data showed that: a) EEG in GCIR treated groups was flattened. b) GCIR reduced GFR ( P <0.01) and pretreatment with EA attenuated this reduction. c) BUN was increased by GCIR ( P <0.001) and pretreatment with EA improved the BUN to normal level. d) Serum creatinine concentration was elevated by GCIR but not significantly, however, in EA+GCIR group serum creatinine was reduced ( P <0.05). e) GCIR induced proteinuria ( P <0.05) but, EA was unable to reduced proteinuria. Results indicate that GCIR impairs certain renal functions and EA as an antioxidant can improve these functions. Our results suggest the possible usefulness of ellagic acid in patients with brain stroke.

Anesthesia patient risk: a quantitative approach to organizational factors and risk management options.

PubMed

Paté-Cornell, M E; Lakats, L M; Murphy, D M; Gaba, D M

1997-08-01

The risk of death or brain damage to anesthesia patients is relatively low, particularly for healthy patients in modern hospitals. When an accident does occur, its cause is usually an error made by the anesthesiologist, either in triggering the accident sequence, or failing to take timely corrective measures. This paper presents a pilot study which explores the feasibility of extending probabilistic risk analysis (PRA) of anesthesia accidents to assess the effects of human and management components on the patient risk. We develop first a classic PRA model for the patient risk per operation. We then link the probabilities of the different accident types to their root causes using a probabilistic analysis of the performance shaping factors. These factors are described here as the "state of the anesthesiologist" characterized both in terms of alertness and competence. We then analyze the effects of different management factors that affect the state of the anesthesiologist and we compute the risk reduction benefits of several risk management policies. Our data sources include the published version of the Australian Incident Monitoring Study as well as expert opinions. We conclude that patient risk could be reduced substantially by closer supervision of residents, the use of anesthesia simulators both in training and for periodic recertification, and regular medical examinations for all anesthesiologists.

Alteration of rod and cone function in children with Usher syndrome.

PubMed

Malm, Eva; Ponjavic, Vesna; Möller, Claes; Kimberling, William J; Stone, Edwin S; Andréasson, Sten

2011-01-01

To evaluate the retinal function, with emphasis on phenotype and rate of progression, in infants and children with different genotypes of Usher syndrome. Fourteen children (2-10 years of age) with retinitis pigmentosa and hearing impairment were examined with full-field electroretinography (ERG) during general anesthesia, ophthalmologic examination, and genetic analysis. Five children were repeatedly examined (follow-up 5-10 years) with full-field ERG under local anesthesia and in 2 children multifocal ERG and optical coherence tomography (OCT) were performed. These results were compared to full-field ERG data from 58 children without retinal eye disorder. Six children were genotyped as Usher 1B, 2A, and 3A. Full-field ERG demonstrated early alterations corresponding to a rod-cone dystrophy in all children. A remaining rod function could be verified in the majority of the children up to 4 years of age. After 4 years of age, there was a further deterioration of the rod function; the progress was severe in Usher types 1 and 2 and moderate in Usher type 3. In all children, the cone function was moderately reduced, in a few cases almost normal. The results from the 58 children without retinal disorder confirm that full-field ERG during general anesthesia is reliable. Multifocal ERG confirmed a preserved central cone function and in OCT there were discrete structural alterations. Full-field ERG during general anesthesia in children with Usher syndrome demonstrates variable phenotypes and different degrees in rate of progression during childhood.

The Effects of Oxygen on Ultrasound-Induced Blood-Brain Barrier Disruption in Mice.

PubMed

McDannold, Nathan; Zhang, Yongzhi; Vykhodtseva, Natalia

2017-02-01

Numerous researchers are investigating the use of microbubble-enhanced ultrasound to disrupt the blood-brain barrier (BBB) and deliver drugs to the brain. This study investigated the impact of using oxygen as a carrier gas for anesthesia on microbubble activity and BBB disruption. Targets in mice were sonicated in combination with administration of Optison microbubbles (100 μL/kg) under isoflurane anesthesia with either oxygen or medical air. A 690-kHz focused ultrasound transducer applied 10-ms bursts at peak pressure amplitudes of 0.46-0.54 MPa (n = 2) or 0.34-0.36 MPa (n = 5). After sonication of two locations in one hemisphere, the carrier gas for the anesthesia was changed and the sonications were repeated in the contralateral hemisphere. The BBB disruption, measured via contrast-enhanced magnetic resonance imaging, was significantly greater (p < 0.001) with medical air than with oxygen. Harmonic emissions were also greater with air (p < 0.001), while the decay rate of the harmonic emissions was 1.5 times faster with oxygen. A good correlation (R 2 , 0.46) was observed between the harmonic emissions strength and magnetic resonance imaging signal enhancement. At 0.46-0.54 MPa, both the occurrence and strength of wideband emissions were greater with medical air. However, at lower peak pressure amplitudes of 0.34-0.36 MPa, the strength and probability for wideband emissions were higher with oxygen. Little or no effects were observed in histology at 0.34-0.36 MPa. These findings show that use of oxygen as a carrier gas can result in a substantial diminution of BBB disruption. These results should be taken into account when comparing studies from different researchers and in translating this method to humans. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Inter- and Intrafractional Positional Uncertainties in Pediatric Radiotherapy Patients With Brain and Head and Neck Tumors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beltran, Chris, E-mail: chris.beltran@stjude.or; Krasin, Matthew J.; Merchant, Thomas E.

2011-03-15

Purpose: To estimate radiation therapy planning margins based on inter- and intrafractional uncertainty for pediatric brain and head and neck tumor patients at different imaging frequencies. Methods: Pediatric patients with brain (n = 83) and head and neck (n = 17) tumors (median age = 7.2 years) were enrolled on an internal review board-approved localization protocol and stratified according to treatment position and use of anesthesia. Megavoltage cone-beam CT (CBCT) was performed before each treatment and after every other treatment. The pretreatment offsets were used to calculate the interfractional setup uncertainty (SU), and posttreatment offsets were used to calculate themore » intrafractional residual uncertainty (RU). The SU and RU are the patient-related components of the setup margin (SM), which is part of the planning target volume (PTV). SU data was used to simulate four intervention strategies using different imaging frequencies and thresholds. Results: The SM based on all patients treated on this study was 2.1 mm (SU = 0.9 mm, RU = 1.9 mm) and varied according to treatment position (supine = 1.8 mm, prone = 2.6 mm) and use of anesthesia (with = 1.7 mm, without = 2.5 mm) because of differences in the RU. The average SU for a 2-mm threshold based on no imaging, once per week imaging, initial five images, and daily imaging was 3.6, 2.1, 2.2, and 0.9 mm, respectively. Conclusion: On the basis of this study, the SM component of the PTV may be reduced to 2 mm for daily CBCT compared with 3.5 mm for weekly CBCT. Considering patients who undergo daily pretreatment CBCT, the SM is larger for those treated in the prone position or smaller for those treated under anesthesia because of differences in the RU.« less

Revolutionary optical sensor for physiological monitoring in the battlefield

NASA Astrophysics Data System (ADS)

Kingsley, Stuart A.; Sriram, Sriram; Pollick, Andrea; Marsh, John

2004-09-01

SRICO has developed a revolutionary approach to physiological status monitoring using state-of-the-art optical chip technology. The company"s patent pending Photrode is a photonic electrode that uses unique optical voltage sensing technology to measure and monitor electrophysiological parameters. The optical-based monitoring system enables dry-contact measurements of EEG and ECG signals that require no surface preparation or conductive gel and non-contact measurements of ECG signals through the clothing. The Photrode applies high performance optical integrated circuit technology, that has been successfully implemented in military & commercial aerospace, missile, and communications applications for sensing and signal transmission. SRICO"s award winning Photrode represents a new paradigm for the measurement of biopotentials in a reliable, convenient, and non-intrusive manner. Photrode technology has significant applications on the battlefield for rapid triage to determine the brain dead from those with viable brain function. An ECG may be obtained over the clothing without any direct skin contact. Such applications would enable the combat medic to receive timely medical information and to make important decisions regarding identification, location, triage priority and treatment of casualties. Other applications for the Photrode include anesthesia awareness monitoring, sleep medicine, mobile medical monitoring for space flight, emergency patient care, functional magnetic resonance imaging, various biopotential signal acquisition (EMG, EOG), and routine neuro and cardio diagnostics.

Development of integrated semiconductor optical sensors for functional brain imaging

NASA Astrophysics Data System (ADS)

Lee, Thomas T.

Optical imaging of neural activity is a widely accepted technique for imaging brain function in the field of neuroscience research, and has been used to study the cerebral cortex in vivo for over two decades. Maps of brain activity are obtained by monitoring intensity changes in back-scattered light, called Intrinsic Optical Signals (IOS), that correspond to fluctuations in blood oxygenation and volume associated with neural activity. Current imaging systems typically employ bench-top equipment including lamps and CCD cameras to study animals using visible light. Such systems require the use of anesthetized or immobilized subjects with craniotomies, which imposes limitations on the behavioral range and duration of studies. The ultimate goal of this work is to overcome these limitations by developing a single-chip semiconductor sensor using arrays of sources and detectors operating at near-infrared (NIR) wavelengths. A single-chip implementation, combined with wireless telemetry, will eliminate the need for immobilization or anesthesia of subjects and allow in vivo studies of free behavior. NIR light offers additional advantages because it experiences less absorption in animal tissue than visible light, which allows for imaging through superficial tissues. This, in turn, reduces or eliminates the need for traumatic surgery and enables long-term brain-mapping studies in freely-behaving animals. This dissertation concentrates on key engineering challenges of implementing the sensor. This work shows the feasibility of using a GaAs-based array of vertical-cavity surface emitting lasers (VCSELs) and PIN photodiodes for IOS imaging. I begin with in-vivo studies of IOS imaging through the skull in mice, and use these results along with computer simulations to establish minimum performance requirements for light sources and detectors. I also evaluate the performance of a current commercial VCSEL for IOS imaging, and conclude with a proposed prototype sensor.

Near-death experiences between science and prejudice.

PubMed

Facco, Enrico; Agrillo, Christian

2012-01-01

Science exists to refute dogmas; nevertheless, dogmas may be introduced when undemonstrated scientific axioms lead us to reject facts incompatible with them. Several studies have proposed psychobiological interpretations of near-death experiences (NDEs), claiming that NDEs are a mere byproduct of brain functions gone awry; however, relevant facts incompatible with the ruling physicalist and reductionist stance have been often neglected. The awkward transcendent look of NDEs has deep epistemological implications, which call for: (a) keeping a rigorously neutral position, neither accepting nor refusing anything a priori; and (b) distinguishing facts from speculations and fallacies. Most available psychobiological interpretations remain so far speculations to be demonstrated, while brain disorders and/or drug administration in critical patients yield a well-known delirium in intensive care and anesthesia, the phenomenology of which is different from NDEs. Facts can be only true or false, never paranormal. In this sense, they cannot be refused a priori even when they appear implausible with respect to our current knowledge: any other stance implies the risk of turning knowledge into dogma and the adopted paradigm into a sort of theology.

Near-death experiences between science and prejudice

PubMed Central

Facco, Enrico; Agrillo, Christian

2012-01-01

Science exists to refute dogmas; nevertheless, dogmas may be introduced when undemonstrated scientific axioms lead us to reject facts incompatible with them. Several studies have proposed psychobiological interpretations of near-death experiences (NDEs), claiming that NDEs are a mere byproduct of brain functions gone awry; however, relevant facts incompatible with the ruling physicalist and reductionist stance have been often neglected. The awkward transcendent look of NDEs has deep epistemological implications, which call for: (a) keeping a rigorously neutral position, neither accepting nor refusing anything a priori; and (b) distinguishing facts from speculations and fallacies. Most available psychobiological interpretations remain so far speculations to be demonstrated, while brain disorders and/or drug administration in critical patients yield a well-known delirium in intensive care and anesthesia, the phenomenology of which is different from NDEs. Facts can be only true or false, never paranormal. In this sense, they cannot be refused a priori even when they appear implausible with respect to our current knowledge: any other stance implies the risk of turning knowledge into dogma and the adopted paradigm into a sort of theology. PMID:22826697

In vivo microscopy of the mouse brain using multiphoton laser scanning techniques

NASA Astrophysics Data System (ADS)

Yoder, Elizabeth J.

2002-06-01

The use of multiphoton microscopy for imaging mouse brain in vivo offers several advantages and poses several challenges. This tutorial begins by briefly comparing multiphoton microscopy with other imaging modalities used to visualize the brain and its activity. Next, an overview of the techniques for introducing fluorescence into whole animals to generate contrast for in vivo microscopy using two-photon excitation is presented. Two different schemes of surgically preparing mice for brain imaging with multiphoton microscopy are reviewed. Then, several issues and problems with in vivo microscopy - including motion artifact, respiratory and cardiac rhythms, maintenance of animal health, anesthesia, and the use of fiducial markers - are discussed. Finally, examples of how these techniques have been applied to visualize the cerebral vasculature and its response to hypercapnic stimulation are provided.

Pulsed-Dye Laser Treatment of Port-Wine Stains in Children: Useful Tips to Avoid General Anesthesia.

PubMed

Alegre-Sánchez, Adrián; Pérez-García, Bibiana; Boixeda, Pablo

2017-09-01

Pulsed dye laser (PDL) treatment of port-wine stains (PWSs) in children is a common procedure performed in most laser units. Pain assessment in our younger patients is a major concern, especially in those with extensive PWSs. The use of general anesthesia (GA) results in pain-free treatment, but its effects on the developing brain are far from totally understood. Thus we propose some tips that avoid the use of GA in most of our young patients, including the use of topical anesthetics and cooling systems, large laser spot size and high frequencies, early and frequent treatment with parents present, and the "introduction" and "pressure" techniques, among others. © 2017 Wiley Periodicals, Inc.

[Examination of diagnosis procedure combination survey data that influence function evaluation coefficient II].

PubMed

Nakajima, Hisato; Yano, Kouya; Nagasawa, Kaoko; Kobayashi, Eiji; Yokota, Kuninobu

2015-01-01

On the basis of Diagnosis Procedure Combination (DPC) survey data, the factors that increase the value of function evaluation coefficient II were considered. A total of 1,505 hospitals were divided into groups I, II, and III, and the following items were considered. 1. Significant differences in function evaluation coefficient II and DPC survey data. 2. Examination of using the Mahalanobis-Taguchi (MT) method. 3. Correlation between function evaluation coefficient II and each DPC survey data item. 1. Function evaluation coefficient II was highest in group II. Group I hospitals showed the highest bed capacity, and numbers of hospitalization days, operations, chemotherapies, radiotherapies and general anesthesia procedures. 2. Using the MT method, we found that the number of ambulance conveyances was effective factor in group I hospitals, the number of general anesthesia procedures was effective factor in group II hospitals, and the bed capacity was effective factor in group III hospitals. 3. In group I hospitals, function evaluation coefficient II significantly correlated to the numbers of ambulance conveyances and chemotherapies. In group II hospitals, function evaluation coefficient II significantly correlated to bed capacity, the numbers of ambulance conveyances, hospitalization days, operations, general anesthesia procedures, and mean hospitalization days. In group III hospitals, function evaluation coefficient II significantly correlated to all items. The factors that improve the value of function evaluation coefficient II were the increases in the numbers of ambulance conveyances, chemotherapies and radiotherapies in group I hospitals, increases in the numbers of hospitalization days, operations, ambulance conveyances and general anesthesia procedures in group II hospitals, and increases in the numbers of hospitalization days, operations and ambulance conveyances. These results indicate that the profit of a hospital will increase, which will lead to medical services of good quality.

The impact of multichannel microelectrode recording (MER) in deep brain stimulation of the basal ganglia.

PubMed

Kinfe, Thomas M; Vesper, Jan

2013-01-01

Deep brain stimulation (DBS) of the basal ganglia (Ncl. subthalamicus, Ncl. ventralis intermedius thalami, globus pallidus internus) has become an evidence-based and well-established treatment option in otherwise refractory movement disorders. The Ncl. subthalamicus (STN) is the target of choice in Parkinson's disease.However, a considerable discussion is currently ongoing with regard to the necessity for micro-electrode recording (MER) in DBS surgery.The present review provides an overview on deep brain stimulation and (MER) of the STN in patients with Parkinson's disease. Detailed description is given concerning the multichannel MER systems nowadays available for DBS of the basal ganglia, especially of the STN, as a useful tool for target refinement. Furthermore, an overview is given of the historical aspects, spatial mapping of the STN by MER, and its impact for accuracy and precision in current functional stereotactic neurosurgery.The pros concerning target refinement by MER means on the one hand, and cons including increased bleeding risk, increased operation time, local or general anesthesia, and single versus multichannel microelectrode recording are discussed in detail. Finally, the authors favor the use of MER with intraoperative testing combined with imaging to achieve a more precise electrode placement, aiming to ameliorate clinical outcome in therapy-resistant movement disorders.

Patients' perceptions of awake and outpatient craniotomy for brain tumor: a qualitative study.

PubMed

Khu, Kathleen Joy; Doglietto, Francesco; Radovanovic, Ivan; Taleb, Faisal; Mendelsohn, Daniel; Zadeh, Gelareh; Bernstein, Mark

2010-05-01

Routine and nonselective use of awake and outpatient craniotomy for supratentorial tumors has been shown to be safe and effective from a medical standpoint. In this study the authors aim was to explore patients' perceptions about awake and outpatient craniotomy. Qualitative research methodology was used. Two semistructured, open-ended interviews were conducted with 27 participants, who were ambulatory adult patients who underwent craniotomy for brain tumor excision between October 2008 and April 2009. The participants were each assigned to one of the following categories: 1) awake outpatient; 2) awake inpatient; 3) outpatient under general anesthesia; and 4) inpatient under general anesthesia. Interviews were audiotaped and transcribed, and the data were subjected to thematic analysis. The following 6 overarching themes emerged from the data: 1) patients had a positive experience with awake craniotomy; 2) patient satisfaction with outpatient surgery was high; 3) patients understood the rationale behind awake surgery; 4) patients were surprised that brain surgery can be done on an outpatient basis; 5) trust in one's surgeon was important; and 6) patients were more concerned about the disease than the procedure. The results reflected positively on the patients' awake and outpatient surgery experience, but there were some areas that require improvement, specifically perioperative pain control and postoperative care. These insights on patients' perspectives can lead to better delivery of care, and ultimately, improved health outcomes.

Anesthesia for Euthanasia Influences mRNA Expression in Healthy Mice and after Traumatic Brain Injury

PubMed Central

Staib-Lasarzik, Irina; Kriege, Oliver; Timaru-Kast, Ralph; Pieter, Dana; Werner, Christian; Engelhard, Kristin

2014-01-01

Abstract Tissue sampling for gene expression analysis is usually performed under general anesthesia. Anesthetics are known to modulate hemodynamics, receptor-mediated signaling cascades, and outcome parameters. The present study determined the influence of anesthetic paradigms typically used for euthanization and tissue sampling on cerebral mRNA expression in mice. Naïve mice and animals with acute traumatic brain injury induced by controlled cortical impact (CCI) were randomized to the following euthanasia protocols (n=10–11/group): no anesthesia (NA), 1 min of 4 vol% isoflurane in room air (ISO), 3 min of a combination of 5 mg/kg midazolam, 0.05 mg/kg fentanyl, and 0.5 mg/kg medetomidine intraperitoneally (COMB), or 3 min of 360 mg/kg chloral hydrate intraperitoneally (CH). mRNA expression of actin-1-related gene (Act1), FBJ murine osteosarcoma viral oncogene homolog B (FosB), tumor necrosis factor alpha (TNFα), heat shock protein beta-1 (HspB1), interleukin (IL)-6, tight junction protein 1 (ZO-1), IL-1ß, cyclophilin A, micro RNA 497 (miR497), and small cajal body-specific RNA 17 were determined by real-time polymerase chain reaction (PCR) in hippocampus samples. In naïve animals, Act1 expression was downregulated in the CH group compared with NA. FosB expression was downregulated in COMB and CH groups compared with NA. CCI reduced Act1 and FosB expression, whereas HspB1 and TNFα expression increased. After CCI, HspB1 expression was significantly higher in ISO, COMB, and CH groups, and TNFα expression was elevated in ISO and COMB groups. MiR497, IL-6, and IL-1ß were upregulated after CCI but not affected by anesthetics. Effects were independent of absolute mRNA copy numbers. The data demonstrate that a few minutes of anesthesia before tissue sampling are sufficient to induce immediate mRNA changes, which seem to predominate in the early-regulated gene cluster. Anesthesia-related effects on gene expression might explain limited reproduciblity of real-time PCR data between studies or research groups and should therefore be considered for quantitative PCR data. PMID:24945082

Continuous intra-articular infusion anesthesia for pain control after total knee arthroplasty: study protocol for a randomized controlled trial.

PubMed

Guo, Da; Cao, Xue-Wei; Liu, Jin-Wen; Ouyang, Wen-Wei; Pan, Jian-Ke; Liu, Jun

2014-06-23

Postoperative pain control after total knee arthroplasty (TKA) remains a great challenge. The management of pain in the immediate postoperative period is one of the most critical aspects to allow speedier rehabilitation and reduce the risk of postoperative complications. Recently, periarticular infiltration anesthesia has become popular, but the outcome is controversial. Some studies have shown transient effects, "rebound pain", or no effectiveness in pain control. Continuous intra-articular infusion technique has been introduced to improve these transient effects, but more clinical studies are needed. Furthermore, the potential risk of early periprosthetic joint infection is causing concerning. We plan to compare continuous intra-articular infusion anesthesia with epidural infusion anesthesia after TKA to assess the effectiveness of this technique in reducing pain, in improving postoperative function, and to look at the evidence for risk of early infection. This trial is a randomized, controlled study. Patients (n = 214) will be randomized into two groups: to receive continuous intra-articular infusion anesthesia (group C); and epidural infusion anesthesia (group E). For the first 3 postoperative days, pain at rest, active range of motion (A-ROM), rescue analgesia and side effects will be recorded. At 3-month and 6-month follow-up, A-ROM, C-reactive protein, erythrocyte sedimentation rate, and synovial fluid cell count and culture will be analyzed. The results from this study will provide clinical evidence on the efficacy of a continuous intra-articular infusion technique in reducing pain, postoperative functional improvement and safety. It will be the first randomized controlled trial to investigate infection risk with local anesthesia after TKA. ClinicalTrials.gov identifier: ChiCTR-TRC-13003999.

Effects of Combined General/Epidural Anesthesia on Hemodynamics, Respiratory Function, and Stress Hormone Levels in Patients with Ovarian Neoplasm Undergoing Laparoscopy.

PubMed

Xu, Qiang; Zhang, Hao; Zhu, Yan-Mei; Shi, Nian-Jun

2016-11-08

BACKGROUND The aim of this study was to evaluate the influence of combined general/epidural anesthesia (GEA) on hemodynamics, respiratory function and stress hormone levels in patients with ovarian neoplasm undergoing laparoscopy. MATERIAL AND METHODS A total of 177 patients with ovarian neoplasm (screened by inclusion/exclusion criteria) receiving laparoscopy were divided into groups G (general anesthesia alone), L1.0 (GEA with 1.0% lidocaine), and L1.5 (GEA with 1.5% lidocaine). Hemodynamics, respiratory parameters and stress hormone levels in the 3 groups were recorded and analyzed. RESULTS Hemodynamic indexes and PaO2/PaCO2 in group L1.0 showed no differences at each time point (all P>0.05). At the end of anesthesia tracheal intubation (T1), 10 min after pneumoperitoneum (T2) and the end of anesthesia tracheal extubation (T3), there were significant differences in hemodynamic indexes, respiratory parameters, epinephrine (E), and noradrenalin (NE) of group G/L1.5, compared with before anesthesia induction (T0) (all P<0.05). Compared with group G, there were big differences in dosage of anesthetics (sufentanil, vecuronium, and propofol) and pharmaceutic adjuvants (ephedrine, atropine, and nitroglycerin), postoperative recovery time, extubation time, and incidence of agitation in group L1.0/L1.5 (all P<0.05). CONCLUSIONS GEA can improve the quality and efficiency in laparoscopy for ovarian neoplasm, with the advantages of reduced anesthetics dosage, satisfactory postoperative analgesia, maintained hemodynamic stability, excellent uterine relaxation, and reduced time of anesthesia induction, surgery, recovery, and extubation. In addition, compared with group L1.5, group L1.0 was more secure and worthy of clinical promotion in laparoscopy.

Postoperative cognitive changes after total knee arthroplasty under regional anesthesia

PubMed Central

Jeon, Young-Tae; Kim, Byung-Gun; Park, Young Ho; Sohn, Hye-Min; Kim, Jungeun; Kim, Seung Chan; An, Seong Soo; Kim, SangYun

2016-01-01

Abstract Background: The type of postoperative cognitive decline after surgery under spinal anesthesia is unknown. We investigated the type of postoperative cognitive decline after total knee arthroplasty (TKA). Neuropsychological testing was conducted and the changes in cerebrospinal fluid (CSF) biomarkers after surgery were evaluated. Methods: Fifteen patients who required bilateral TKA at a 1-week interval under spinal anesthesia were included. Neuropsychological tests were performed twice, once the day before the first operation and just before the second operation (usually 1 week after the first test) to determine cognitive decline. Validated neuropsychological tests were used to examine 4 types of cognitive decline: memory, frontal-executive, language-semantic, and others. Concentrations of CSF amyloid peptide, tau protein, and S100B were measured twice during spinal anesthesia at a 1-week interval. The patients showed poor performance in frontal-executive function (forward digit span, semantic fluency, letter-phonemic fluency, and Stroop color reading) at the second compared to the first neuropsychological assessment. Results: S100B concentration decreased significantly 1 week after the operation compared to the basal value (638 ± 178 vs 509 ± 167 pg/mL) (P = 0.019). Amyloid protein β1–42, total tau, and phosphorylated tau concentrations tended to decrease but the changes were not significant. Conclusion: Our results suggest that frontal-executive function declined 1 week after TKA under spinal anesthesia. The CSF biomarker analysis indicated that TKA under regional anesthesia might not cause neuronal damage. PMID:28033253

Intraoperative dorsal language network mapping by using single-pulse electrical stimulation.

PubMed

Yamao, Yukihiro; Matsumoto, Riki; Kunieda, Takeharu; Arakawa, Yoshiki; Kobayashi, Katsuya; Usami, Kiyohide; Shibata, Sumiya; Kikuchi, Takayuki; Sawamoto, Nobukatsu; Mikuni, Nobuhiro; Ikeda, Akio; Fukuyama, Hidenao; Miyamoto, Susumu

2014-09-01

The preservation of language function during brain surgery still poses a challenge. No intraoperative methods have been established to monitor the language network reliably. We aimed to establish intraoperative language network monitoring by means of cortico-cortical evoked potentials (CCEPs). Subjects were six patients with tumors located close to the arcuate fasciculus (AF) in the language-dominant left hemisphere. Under general anesthesia, the anterior perisylvian language area (AL) was first defined by the CCEP connectivity patterns between the ventrolateral frontal and temporoparietal area, and also by presurgical neuroimaging findings. We then monitored the integrity of the language network by stimulating AL and by recording CCEPs from the posterior perisylvian language area (PL) consecutively during both general anesthesia and awake condition. High-frequency electrical stimulation (ES) performed during awake craniotomy confirmed language function at AL in all six patients. Despite an amplitude decline (≤32%) in two patients, CCEP monitoring successfully prevented persistent language impairment. After tumor removal, single-pulse ES was applied to the white matter tract beneath the floor of the removal cavity in five patients, in order to trace its connections into the language cortices. In three patients in whom high-frequency ES of the white matter produced naming impairment, this "eloquent" subcortical site directly connected AL and PL, judging from the latencies and distributions of cortico- and subcortico-cortical evoked potentials. In conclusion, this study provided the direct evidence that AL, PL, and AF constitute the dorsal language network. Intraoperative CCEP monitoring is clinically useful for evaluating the integrity of the language network. Copyright © 2014 Wiley Periodicals, Inc.

Monitoring the Depth of Anesthesia Using a New Adaptive Neurofuzzy System.

PubMed

Shalbaf, Ahmad; Saffar, Mohsen; Sleigh, Jamie W; Shalbaf, Reza

2018-05-01

Accurate and noninvasive monitoring of the depth of anesthesia (DoA) is highly desirable. Since the anesthetic drugs act mainly on the central nervous system, the analysis of brain activity using electroencephalogram (EEG) is very useful. This paper proposes a novel automated method for assessing the DoA using EEG. First, 11 features including spectral, fractal, and entropy are extracted from EEG signal and then, by applying an algorithm according to exhaustive search of all subsets of features, a combination of the best features (Beta-index, sample entropy, shannon permutation entropy, and detrended fluctuation analysis) is selected. Accordingly, we feed these extracted features to a new neurofuzzy classification algorithm, adaptive neurofuzzy inference system with linguistic hedges (ANFIS-LH). This structure can successfully model systems with nonlinear relationships between input and output, and also classify overlapped classes accurately. ANFIS-LH, which is based on modified classical fuzzy rules, reduces the effects of the insignificant features in input space, which causes overlapping and modifies the output layer structure. The presented method classifies EEG data into awake, light, general, and deep states during anesthesia with sevoflurane in 17 patients. Its accuracy is 92% compared to a commercial monitoring system (response entropy index) successfully. Moreover, this method reaches the classification accuracy of 93% to categorize EEG signal to awake and general anesthesia states by another database of propofol and volatile anesthesia in 50 patients. To sum up, this method is potentially applicable to a new real-time monitoring system to help the anesthesiologist with continuous assessment of DoA quickly and accurately.

General anesthesia selectively disrupts astrocyte calcium signaling in the awake mouse cortex

PubMed Central

Thrane, Alexander Stanley; Zeppenfeld, Douglas; Lou, Nanhong; Xu, Qiwu; Nagelhus, Erlend Arnulf; Nedergaard, Maiken

2012-01-01

Calcium signaling represents the principle pathway by which astrocytes respond to neuronal activity. General anesthetics are routinely used in clinical practice to induce a sleep-like state, allowing otherwise painful procedures to be performed. Anesthetic drugs are thought to mainly target neurons in the brain and act by suppressing synaptic activity. However, the direct effect of general anesthesia on astrocyte signaling in awake animals has not previously been addressed. This is a critical issue, because calcium signaling may represent an essential mechanism through which astrocytes can modulate synaptic activity. In our study, we performed calcium imaging in awake head-restrained mice and found that three commonly used anesthetic combinations (ketamine/xylazine, isoflurane, and urethane) markedly suppressed calcium transients in neocortical astrocytes. Additionally, all three anesthetics masked potentially important features of the astrocyte calcium signals, such as synchronized widespread transients that appeared to be associated with arousal in awake animals. Notably, anesthesia affected calcium transients in both processes and soma and depressed spontaneous signals, as well as calcium responses, evoked by whisker stimulation or agonist application. We show that these calcium transients are inositol 1,4,5-triphosphate type 2 receptor (IP3R2)-dependent but resistant to a local blockade of glutamatergic or purinergic signaling. Finally, we found that doses of anesthesia insufficient to affect neuronal responses to whisker stimulation selectively suppressed astrocyte calcium signals. Taken together, these data suggest that general anesthesia may suppress astrocyte calcium signals independently of neuronal activity. We propose that these glial effects may constitute a nonneuronal mechanism for sedative action of anesthetic drugs. PMID:23112168

Anesthesia/Surgery Induces Cognitive Impairment in Female Alzheimer's Disease Transgenic Mice.

PubMed

Zhang, Ce; Zhang, Yiying; Shen, Yuan; Zhao, Guoqing; Xie, Zhongcong; Dong, Yuanlin

2017-01-01

Anesthesia and/or surgery may promote Alzheimer's disease (AD) by accelerating its neuropathogenesis. Other studies showed different findings. However, the potential sex difference among these studies has not been well considered, and it is unknown whether male or female AD patients are more vulnerable to develop postoperative cognitive dysfunction. We therefore set out to perform a proof of concept study to determine whether anesthesia and surgery can have different effects in male and female AD transgenic (Tg) mice, and in female AD Tg plus Cyclophilin D knockout (CypD KO) mice. The mice received an abdominal surgery under sevoflurane anesthesia (anesthesia/surgery). Fear Conditioning System (FCS) was used to assess the cognitive function. Hippocampal levels of synaptic marker postsynaptic density 95 (PSD-95) and synaptophysin (SVP) were measured using western blot analysis. Here we showed that the anesthesia/surgery decreased the freezing time in context test of FCS at 7 days after the anesthesia/surgery in female, but not male, mice. The anesthesia/surgery reduced hippocampus levels of synaptic marker PSD-95 and SVP in female, but not male, mice. The anesthesia/surgery induced neither reduction in freezing time in FCS nor decreased hippocampus levels of PSD-95 and SVP in the AD Tg plus CypD KO mice. These data suggest that the anesthesia/surgery induced a sex-dependent cognitive impairment and reduction in hippocampus levels of synaptic markers in AD Tg mice, potentially via a mitochondria-associated mechanism. These findings could promote clinical investigations to determine whether female AD patients are more vulnerable to the development of postoperative cognitive dysfunction.

Susceptibility of Primary Sensory Cortex to Spreading Depolarizations.

PubMed

Bogdanov, Volodymyr B; Middleton, Natalie A; Theriot, Jeremy J; Parker, Patrick D; Abdullah, Osama M; Ju, Y Sungtaek; Hartings, Jed A; Brennan, K C

2016-04-27

Spreading depolarizations (SDs) are recognized as actors in neurological disorders as diverse as migraine and traumatic brain injury (TBI). Migraine aura involves sensory percepts, suggesting that sensory cortices might be intrinsically susceptible to SDs. We used optical imaging, MRI, and field potential and potassium electrode recordings in mice and electrocorticographic recordings in humans to determine the susceptibility of different brain regions to SDs. Optical imaging experiments in mice under isoflurane anesthesia showed that both cortical spreading depression and terminal anoxic depolarization arose preferentially in the whisker barrel region of parietal sensory cortex. MRI recordings under isoflurane, ketamine/xylazine, ketamine/isoflurane, and urethane anesthesia demonstrated that the depolarizations did not propagate from a subcortical source. Potassium concentrations showed larger increases in sensory cortex, suggesting a mechanism of susceptibility. Sensory stimulation biased the timing but not the location of depolarization onset. In humans with TBI, there was a trend toward increased incidence of SDs in parietal/temporal sensory cortex compared with other regions. In conclusion, SDs are inducible preferentially in primary sensory cortex in mice and most likely in humans. This tropism can explain the predominant sensory phenomenology of migraine aura. It also demonstrates that sensory cortices are vulnerable in brain injury. Spreading depolarizations (SDs) are involved in neurologic disorders as diverse as migraine and traumatic brain injury. In migraine, the nature of aura symptoms suggests that sensory cortex may be preferentially susceptible. In brain injury, SDs occur at a vulnerable time, during which the issue of sensory stimulation is much debated. We show, in mouse and human, that sensory cortex is more susceptible to SDs. We find that sensory stimulation biases the timing but not the location of the depolarizations. Finally, we show a relative impairment of potassium clearance in sensory cortex, providing a potential mechanism for the susceptibility. Our data help to explain the sensory nature of the migraine aura and reveal that sensory cortices are vulnerable in brain injury. Copyright © 2016 the authors 0270-6474/16/364733-11$15.00/0.

Susceptibility of Primary Sensory Cortex to Spreading Depolarizations

PubMed Central

Bogdanov, Volodymyr B.; Middleton, Natalie A.; Theriot, Jeremy J.; Parker, Patrick D.; Abdullah, Osama M.; Ju, Y. Sungtaek; Hartings, Jed A.

2016-01-01

Spreading depolarizations (SDs) are recognized as actors in neurological disorders as diverse as migraine and traumatic brain injury (TBI). Migraine aura involves sensory percepts, suggesting that sensory cortices might be intrinsically susceptible to SDs. We used optical imaging, MRI, and field potential and potassium electrode recordings in mice and electrocorticographic recordings in humans to determine the susceptibility of different brain regions to SDs. Optical imaging experiments in mice under isoflurane anesthesia showed that both cortical spreading depression and terminal anoxic depolarization arose preferentially in the whisker barrel region of parietal sensory cortex. MRI recordings under isoflurane, ketamine/xylazine, ketamine/isoflurane, and urethane anesthesia demonstrated that the depolarizations did not propagate from a subcortical source. Potassium concentrations showed larger increases in sensory cortex, suggesting a mechanism of susceptibility. Sensory stimulation biased the timing but not the location of depolarization onset. In humans with TBI, there was a trend toward increased incidence of SDs in parietal/temporal sensory cortex compared with other regions. In conclusion, SDs are inducible preferentially in primary sensory cortex in mice and most likely in humans. This tropism can explain the predominant sensory phenomenology of migraine aura. It also demonstrates that sensory cortices are vulnerable in brain injury. SIGNIFICANCE STATEMENT Spreading depolarizations (SDs) are involved in neurologic disorders as diverse as migraine and traumatic brain injury. In migraine, the nature of aura symptoms suggests that sensory cortex may be preferentially susceptible. In brain injury, SDs occur at a vulnerable time, during which the issue of sensory stimulation is much debated. We show, in mouse and human, that sensory cortex is more susceptible to SDs. We find that sensory stimulation biases the timing but not the location of the depolarizations. Finally, we show a relative impairment of potassium clearance in sensory cortex, providing a potential mechanism for the susceptibility. Our data help to explain the sensory nature of the migraine aura and reveal that sensory cortices are vulnerable in brain injury. PMID:27122032

A comparison of liver function after hepatectomy with inflow occlusion between sevoflurane and propofol anesthesia.

PubMed

Song, J C; Sun, Y M; Yang, L Q; Zhang, M Z; Lu, Z J; Yu, W F

2010-10-01

In this study, we compared liver function tests after hepatectomy with inflow occlusion as a function of propofol versus sevoflurane anesthesia. One hundred patients undergoing elective liver resection with inflow occlusion were randomized into a sevoflurane group or a propofol group. General anesthesia was induced with 3 μg/kg fentanyl, 0.2 mg/kg cisatracurium, and target-controlled infusion of propofol, set at a plasma target concentration of 4 to 6 μg/mL, or sevoflurane initially started at 8%. Anesthesia was maintained with target-controlled infusion of propofol (2-4 μg/mL) or sevoflurane (1.5%-2.5%). The primary end point was postoperative liver injury assessed by peak values of liver transaminases. Transaminase levels peaked between the first and the third postoperative day. Peak alanine aminotransferase was 504 and 571 U/L in the sevoflurane group and the propofol group, respectively. Peak aspartate aminotransferase was 435 U/L after sevoflurane and 581 U/L in the propofol group. There were no significant differences in peak alanine aminotransferase or peak aspartate aminotransferase between groups. Other liver function tests including bilirubin and alkaline phosphatase, and peak values of white blood cell counts and creatinine, were also not different between groups. Sevoflurane and propofol anesthetics resulted in similar patterns of liver function tests after hepatectomy with inflow occlusion. These data suggest that the 2 anesthetics are equivalent in this clinical context.

Reversal of soft-tissue local anesthesia with phentolamine mesylate in adolescents and adults.

PubMed

Hersh, Elliot V; Moore, Paul A; Papas, Athena S; Goodson, J Max; Navalta, Laura A; Rogy, Siegfried; Rutherford, Bruce; Yagiela, John A

2008-08-01

The authors conducted two multicenter, randomized, double-blinded, controlled Phase III clinical trials to study the efficacy and safety of phentolamine mesylate (PM) in shortening the duration and burden of soft-tissue anesthesia. The study involved 484 subjects who received one of four commercially available local anesthetic solutions containing vasoconstrictors for restorative or scaling procedures. On completion of the dental procedure, subjects randomly received a PM or a sham injection (an injection in which a needle does not penetrate the soft tissue) in the same site as the local anesthetic injection. The investigators measured the duration of soft-tissue anesthesia by using standardized lip- and tongue-tapping procedures every five minutes for five hours. They also evaluated functional measures and subject-perceived altered function, sensation, appearance and safety. Median recovery times in the lower lip and tongue for subjects in the PM group were 70 minutes and 60 minutes, respectively. Median recovery times in the lower lip and tongue for subjects in the sham group were 155 minutes and 125 minutes, respectively. Upper lip median recovery times were 50 minutes for subjects in the PM group and 133 minutes for subjects in the sham group. These differences were significant (P < .0001). Recovery from actual functional deficits and subject-perceived altered function, sensation and appearance also showed significant differences between the PM and the sham groups. PM was efficacious and safe in reducing the duration of local anesthetic- induced soft-tissue numbness and its associated functional deficits. Clinicians can use PM to accelerate reversal of soft-tissue anesthesia and the associated functional deficits.

The Unique Role of the Pediatric Clinical Research Nurse in Anesthesia: An Interdisciplinary Collaboration.

PubMed

Dube, Christine; Young, Vanessa; Anderson, Michelle; Barton, Brenda; Leahy, Izabela

2017-08-01

This article describes the distinctive function of the pediatric clinical research nurse (CRN) in the anesthesia setting. The pediatric CRN in anesthesia acts as a liaison between families and the research team and is the major nexus between the principal investigator or anesthesiologist on a study, and the collaborating surgeons from many different departments. This is unique because the CRNs collaborate with physicians in specialties that can include plastics, urology, neurosurgery, orthopaedics, otolaryngology, cardiology, critical care, and many other departments. The profession requires a breath of knowledge ranging from clinical understanding of diseases, surgical procedures, and recovery to cognitive and developmental stages, to expertise in the research protocol process. Our objective was to describe these specialized activities of the pediatric anesthesia CRN, with focus on care coordination, communication, and continuity of care. Defining this role will enhance the quality of clinical research conducted by the CRN in anesthesia and may influence the development of novel medical treatments. Copyright © 2016 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

Recovery of storage and emptying functions of the urinary bladder after spinal anesthesia with lidocaine and with bupivacaine in men.

PubMed

Kamphuis, E T; Ionescu, T I; Kuipers, P W; de Gier, J; van Venrooij, G E; Boon, T A

1998-02-01

The aim of this study was to evaluate and compare the effects of spinal anesthesia with lidocaine and with bupivacaine on urinary bladder function in healthy men who were scheduled for minor orthopaedic surgical procedures. Twenty men were randomly allocated to receive either bupivacaine or lidocaine. Before spinal anesthesia, filling cystometry was performed with the patient in the supine position and a pressure flow study was done with the patient in the standing position. After operation, cystometric measurements were continued until the patient could void urine spontaneously. The levels of analgesia and of motor blockade were recorded. The urge to void disappeared immediately after injection of the local anesthetics. There was no difference in the duration of lower extremity motor blockade between bupivacaine and lidocaine. Detrusor blockade lasted significantly longer in the bupivacaine group (means +/- SD, 460 +/- 60 min) than in the lidocaine group (235 +/- 30 min). Total fluid intake and urine volume accumulated during the detrusor blockade were significantly higher in the bupivacaine group than in the lidocaine group. In the bupivacaine group, the total volume of accumulated urine (875 +/- 385 ml) was also significantly higher than cystometric bladder capacity (505 +/- 120 ml) with the risk of over distension of the bladder. Spontaneous voiding of urine did not occur until segmental sensory analgesia had regressed to the third sacral segment. Spinal anesthesia with lidocaine and with bupivacaine causes a clinically significant disturbance of bladder function due to interruption of the micturition reflex. The urge to void disappears quickly and bladder function remains impaired until the block has regressed to the third sacral segment in all patients. With long-acting local anesthetics, the volume of accumulated urine may exceed the cystometric bladder capacity. With respect to recovery of urinary bladder function, the use of short-acting local anesthetics for spinal anesthesia seems to be preferable.

Anesthesia Management of Organ Donors.

PubMed

Xia, Victor W; Braunfeld, Michelle

2017-09-01

The shortage of suitable organs is the biggest obstacle for transplants. At present, most organs for transplant in the United States are from donation after neurologic determination of death (brain death). Potential organs for transplant need to maintain their viability during a series of insults, including the original disease, physiologic derangements during the dying process, ischemia, and reperfusion. Proper donor management before, during, and after procurement has potential to increase the number and quality of organs from donors. Anesthesiologists need to understand the physiologic derangements associated with brain death and the updated donor management during the periprocurement period. Copyright © 2017 Elsevier Inc. All rights reserved.

Simultaneous two-photon imaging of cerebral oxygenation and capillary blood flow in atherosclerotic mice

NASA Astrophysics Data System (ADS)

Lu, Xuecong; Li, Baoqiang; Moeini, Mohammad; Lesage, Frédéric

2017-02-01

Gradual changes in brain microvasculature and cerebral capillary blood flow occurring with atherosclerosis may significantly contribute to cognition decline due to their role in brain tissue oxygenation. However, previous stud- ies of the relationship between cerebral capillary blood flow and brain tissue oxygenation are limited. This study aimed to investigate vascular and concomitant changes in brain tissue pO2 with atherosclerosis. Experiments in young healthy C57B1/6 mice (n=6 , WT), young atherosclerotic mice (n=6 , ATX Y) and old atherosclerotic mice (n=6 , ATX O) were performed imaging on the left sensory-motor cortex at resting state under urethane (1.5 g/kg) anesthesia using two-photon fluorescence microscopy. The results showed that pO2 around capillaries, correlated with red blood cell (RBC) flux, increased with atherosclerosis.

Nitrous oxide-induced slow and delta oscillations.

PubMed

Pavone, Kara J; Akeju, Oluwaseun; Sampson, Aaron L; Ling, Kelly; Purdon, Patrick L; Brown, Emery N

2016-01-01

Switching from maintenance of general anesthesia with an ether anesthetic to maintenance with high-dose (concentration >50% and total gas flow rate >4 liters per minute) nitrous oxide is a common practice used to facilitate emergence from general anesthesia. The transition from the ether anesthetic to nitrous oxide is associated with a switch in the putative mechanisms and sites of anesthetic action. We investigated whether there is an electroencephalogram (EEG) marker of this transition. We retrospectively studied the ether anesthetic to nitrous oxide transition in 19 patients with EEG monitoring receiving general anesthesia using the ether anesthetic sevoflurane combined with oxygen and air. Following the transition to nitrous oxide, the alpha (8-12 Hz) oscillations associated with sevoflurane dissipated within 3-12 min (median 6 min) and were replaced by highly coherent large-amplitude slow-delta (0.1-4 Hz) oscillations that persisted for 2-12 min (median 3 min). Administration of high-dose nitrous oxide is associated with transient, large amplitude slow-delta oscillations. We postulate that these slow-delta oscillations may result from nitrous oxide-induced blockade of major excitatory inputs (NMDA glutamate projections) from the brainstem (parabrachial nucleus and medial pontine reticular formation) to the thalamus and cortex. This EEG signature of high-dose nitrous oxide may offer new insights into brain states during general anesthesia. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Nitrous oxide-induced slow and delta oscillations

PubMed Central

Pavone, Kara J.; Akeju, Oluwaseun; Sampson, Aaron; Ling, Kelly; Purdon, Patrick L.; Brown, Emery N.

2015-01-01

Objectives Switching from maintenance of general anesthesia with an ether anesthetic to maintenance with high-dose (concentration > 50% and total gas flow rate > 4 liters per minute) nitrous oxide is a common practice used to facilitate emergence from general anesthesia. The transition from the ether anesthetic to nitrous oxide is associated with a switch in the putative mechanisms and sites of anesthetic action. We investigated whether there is an electroencephalogram (EEG) marker of this transition. Methods We retrospectively studied the ether anesthetic to nitrous oxide transition in 19 patients with EEG monitoring receiving sevoflurane, oxygen and air for general anesthesia maintenance. Results Following the transition to nitrous oxide, the alpha (8 to 12 Hz) oscillations associated with sevoflurane dissipated within 3 to 12 minutes (median 6 minutes) and were replaced by highly coherent large-amplitude slow-delta (0.1 to 4 Hz) oscillations that persisted for 2 to 12 minutes (median 3 minutes). Conclusions Administration of high-dose nitrous oxide is associated with transient, large amplitude slow-delta oscillations. Significance We postulate that these slow-delta oscillations may result from nitrous oxide-induced blockade of major excitatory inputs (NMDA glutamate projections) from the brainstem (parabrachial nucleus and medial pontine reticular formation) to the thalamus and cortex. This EEG signature of high-dose nitrous oxide may offer new insights into brain states during general anesthesia. PMID:26118489

Neurophysiologic intraoperative monitoring of the vestibulocochlear nerve.

PubMed

Simon, Mirela V

2011-12-01

Neurosurgical procedures involving the skull base and structures within can pose a significant risk of damage to the brain stem and cranial nerves. This can have life-threatening consequences and/or result in devastating neurologic deficits. Over the past decade, intraoperative neurophysiology has significantly evolved and currently offers a great tool for live monitoring of the integrity of nervous structures. Thus, dysfunction can be identified early and prompt modification of the surgical management or operating conditions, leads to avoidance of permanent structural damage.Along these lines, the vestibulocochlear nerve (CN VIII) and, to a greater extent, the auditory pathways as they pass through the brain stem are especially at risk during cerebelopontine angle (CPA), posterior/middle fossa, or brain stem surgery. CN VIII can be damaged by several mechanisms, from vascular compromise to mechanical injury by stretch, compression, dissection, and heat injury. Additionally, cochlea itself can be significantly damaged during temporal bone drilling, by noise, mechanical destruction, or infarction, and because of rupture, occlusion, or vasospasm of the internal auditory artery.CN VIII monitoring can be successfully achieved by live recording of the function of one of its parts, the cochlear or auditory nerve (AN), using the brain stem auditory evoked potentials (BAEPs), electrocochleography (ECochG), and compound nerve action potentials (CNAPs) of the cochlear nerve.This is a review of these techniques, their principle, applications, methodology, interpretation of the evoked responses, and their change from baseline, within the context of surgical and anesthesia environments, and finally the appropriate management of these changes.

Memantine elicits spinal blockades of motor function, proprioception, and nociception in rats.

PubMed

Chen, Yu-Wen; Chiu, Chong-Chi; Liu, Kuo-Sheng; Hung, Ching-Hsia; Wang, Jhi-Joung

2015-12-01

Although memantine blocks sodium currents and produces local skin anesthesia, spinal anesthesia with memantine is unknown. The purpose of the study was to evaluate the local anesthetic effect of memantine in spinal anesthesia and its comparison with a widely used local anesthetic lidocaine. After intrathecally injecting the rats with five doses of each drug, the dose-response curves of memantine and lidocaine were constructed. The potencies of the drugs and durations of spinal anesthetic effects on motor function, proprioception, and nociception were compared with those of lidocaine. We showed that memantine produced dose-dependent spinal blockades in motor function, proprioception, and nociception. On a 50% effective dose (ED50 ) basis, the rank of potency was lidocaine greater than memantine (P < 0.05 for the differences). At the equipotent doses (ED25 , ED50 , ED75 ), the block duration produced by memantine was longer than that produced by lidocaine (P < 0.05 for the differences). Memantine, but not lidocaine, displayed more sensory/nociceptive block than motor block. The preclinical data demonstrated that memantine is less potent than lidocaine, whereas memantine produces longer duration of spinal anesthesia than lidocaine. Memantine shows a more sensory-selective action over motor blockade. © 2015 Société Française de Pharmacologie et de Thérapeutique.

[Role of the intraoperative electrical brain stimulation in conserving the speech and language function in neurosurgical procedures on conscious patients].

PubMed

Eross, Loránd; Fekete, Gábor; Entz, László; Fabó, Dániel; Borbély, Csaba; Kozák, Lajos Rudolf; Andrejkovics, Mónika; Czirják, Sándor; Fedorcsák, Imre; Novák, László; Bognár, László

2012-09-30

To summarize the results gained with awake craniotomies, which were performed in either low grade glioma patients or epilepsy surgical patients whose tumor or epileptogenic zone, was in the vicinity of eloquent, mostly language, cortices. PATIENT SELECTION AND METHODS: In our retrospective study we selected 16 patients who were operated awake between 1999-2011 at the Neurosurgical Department of MAV Kórház Budapest, or at the National Institute of Neurosciences in Budapest, or at the Neurosurgical Department of the University of Debrecen in Debrecen. In the presurgical evaluation if it was possible we performed functional magnetic resonance imaging, tractography and detailed neuropsychological testing. At the National Institute of Neurosciences all patients were operated with the aid of MR guided neuronavigation. Anesthesia was carried out without complications in all of the 16 cases. Monitoring of sleep deepness has significantly contributed to the safety of anesthesia during the superficial anesthezied states of the operation. The intraoperative neuropsychological tasks used for testing language were sensitive enough to judge the little disturbances in speech during stimulation. Stimulation evoked seizures could be adequately managed during surgery and did not influence the outcome of the procedures. The use of neuronavigation helped significantly by planning the optimal place for the craniotomy and by intraoperative orientation. Awake craniotomies require well practiced surgical teams, which requires the cooperation of neuro-anesthesiologits, neurosurgeons, neuropsychologist and electrophysiologists. It has two goals, first to reduce the time of surgery to minimize surgical complications, secondly the detailed intraoperative mapping of cognitive and motor functions to avoid any neurological deficit. The intraoperative anatomical data provided by the neuronavigation and the functional data provided by awake intraoperative stimulation of the patient together serve the safety of the patient which is essential in the neurologically minimal invasive neurosurgical approach of the 21st century.

Safety Aspects of Postanesthesia Care Unit Discharge without Motor Function Assessment after Spinal Anesthesia: A Randomized, Multicenter, Semiblinded, Noninferiority, Controlled Trial.

PubMed

Aasvang, Eske Kvanner; Jørgensen, Christoffer Calov; Laursen, Mogens Berg; Madsen, Jacob; Solgaard, Søren; Krøigaard, Mogens; Kjærsgaard-Andersen, Per; Mandøe, Hans; Hansen, Torben Bæk; Nielsen, Jørgen Ulrich; Krarup, Niels; Skøtt, Annette Elisabeth; Kehlet, Henrik

2017-06-01

Postanesthesia care unit (PACU) discharge without observation of lower limb motor function after spinal anesthesia has been suggested to significantly reduce PACU stay and enhance resource optimization and early rehabilitation but without enough data to allow clinical recommendations. A multicenter, semiblinded, noninferiority randomized controlled trial of discharge from the PACU with or without assessment of lower limb motor function after elective total hip or knee arthroplasty under spinal anesthesia was undertaken. The primary outcome was frequency of a successful fast-track course (length of stay 4 days or less and no 30-day readmission). Noninferiority would be declared if the odds ratio (OR) for a successful fast-track course was no worse for those patients receiving no motor function assessment versus those patients receiving motor function assessment by OR = 0.68. A total of 1,359 patients (98.8% follow-up) were available for analysis (93% American Society of Anesthesiologists class 1 to 2). The primary outcome occurred in 92.2% and 92.0%, corresponding to no motor function assessment being noninferior to motor function assessment with OR 0.97 (95% CI, 0.70 to 1.35). Adverse events in the ward during the first 24 h occurred in 5.8% versus 7.4% with or without motor function assessment, respectively (OR, 0.77; 95% CI, 0.5 to 1.19, P = 0.24). PACU discharge without assessment of lower limb motor function after spinal anesthesia for total hip or knee arthroplasty was noninferior to motor function assessment in achieving length of stay 4 days or less or 30-day readmissions. Because a nonsignificant tendency toward increased adverse events during the first 24 h in the ward was discovered, further safety data are needed in patients without assessment of lower limb motor function before PACU discharge.

[When a patient falls (asleep) and can't get up: conversion disorder - paraplegia following general anesthesia].

PubMed

Mason, Chawla LaToya

This case report describes the rare occurrence of paraplegia caused by conversion disorder in a woman who received general anesthesia for breast surgery. A 46-year-old healthy woman received general anesthesia for excision of a left breast fibroepithelial lesion. In the post-anesthesia care unit, she reported bilateral loss of both sensation and motor function below the knees. Physical signs and symptoms did not correlate with any anatomical or neurological patterns; imaging revealed no abnormalities. Psychiatric consultation was performed wherein familial stressor circumstances were identified, leading to diagnosis and management of conversion disorder. Conversion disorder is characterized by alteration of physical function due to expression of an underlying psychological ailment. Its diagnosis requires thorough evaluation including appropriate workup to exclude organic causes. The meshing together of anesthesiology and psychiatry - as demonstrated by this case report - offers an opportunity to highlight important information pertaining to the definition, diagnosis, and management of conversion disorder as it may be encountered in the postanesthesia recovery period. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Restructuring consciousness -the psychedelic state in light of integrated information theory.

PubMed

Gallimore, Andrew R

2015-01-01

The psychological state elicited by the classic psychedelics drugs, such as LSD and psilocybin, is one of the most fascinating and yet least understood states of consciousness. However, with the advent of modern functional neuroimaging techniques, the effect of these drugs on neural activity is now being revealed, although many of the varied phenomenological features of the psychedelic state remain challenging to explain. Integrated information theory (IIT) is one of the foremost contemporary theories of consciousness, providing a mathematical formalization of both the quantity and quality of conscious experience. This theory can be applied to all known states of consciousness, including the psychedelic state. Using the results of functional neuroimaging data on the psychedelic state, the effects of psychedelic drugs on both the level and structure of consciousness can be explained in terms of the conceptual framework of IIT. This new IIT-based model of the psychedelic state provides an explanation for many of its phenomenological features, including unconstrained cognition, alterations in the structure and meaning of concepts and a sense of expanded awareness. This model also suggests that whilst cognitive flexibility, creativity, and imagination are enhanced during the psychedelic state, this occurs at the expense of cause-effect information, as well as degrading the brain's ability to organize, categorize, and differentiate the constituents of conscious experience. Furthermore, the model generates specific predictions that can be tested using a combination of functional imaging techniques, as has been applied to the study of levels of consciousness during anesthesia and following brain injury.

Synchronization software for automation in anesthesia.

PubMed

Bressan, Nadja; Castro, Ana; Brás, Susana; Oliveira, Hélder P; Ribeiro, Lénio; Ferreira, David A; Antunes, Luís; Amorim, Pedro; Nunes, Catarina S

2007-01-01

This work presents the development of a software for data acquisition and control (ASYS) on a clinical setup. Similar to the industrial Supervisory Control And Data Acquisition (SCADA) the software assembles a Target Controlled Infusion (TCI) monitoring and supervisory control data in real time from devices in a surgical room. The software is not a full controller since the TCI systems comprehend permanent interaction from the anesthesiologist. Based on pharmacokinetic models, the effect-site and plasma concentrations can be related with the drug dose infused and vice versa. The software determines the infusion rates of the drug which are given as commands to the infusion pumps. This software provides the anesthesiologist with a trustworthy tool for managing a safe and balanced anesthesia. Since it also incorporates the acquisition and display of patients brain signals.

Laparoscopic cholecystectomy under spinal anesthesia: comparative study between conventional-dose and low-dose hyperbaric bupivacaine

PubMed Central

Imbelloni, Luiz Eduardo; Sant’Anna, Raphael; Fornasari, Marcos; Fialho, José Carlos

2011-01-01

Background Laparoscopic cholecystectomy has the advantages of causing less postoperative pain and requiring a short hospital stay, and therefore is the treatment of choice for cholelithiasis. This study was designed to compare spinal anesthesia using hyperbaric bupivacaine given as a conventional dose by lumbar puncture or as a low-dose by thoracic puncture. Methods A total of 140 patients with symptomatic gallstone disease were randomized to undergo laparoscopic cholecystectomy with low-pressure CO2 pneumoperitoneum under spinal anesthesia using either conventional lumbar spinal anesthesia (hyperbaric bupivacaine 15 mg and fentanyl 20 mg) or low-dose thoracic spinal anesthesia (hyperbaric bupivacaine 7.5 mg and fentanyl 20 μg). Intraoperative parameters, postoperative pain, complications, recovery time, and patient satisfaction at follow-up were compared between the two treatment groups. Results All procedures were completed under spinal anesthesia, with no cases needing conversion to general anesthesia. Values for time for block to reach the T3 dermatomal level, duration of motor and sensory block, and hypotensive events were significantly lower with low-dose bupivacaine. Postoperative pain was higher for low-dose hyperbaric bupivacaine at 6 and 12 hours. All patients were discharged after 24 hours. Follow-up 1 week postoperatively showed all patients to be satisfied and to be keen advocates of spinal anesthesia. Conclusion Laparoscopic cholecystectomy can be performed successfully under spinal anesthesia. A small dose of hyperbaric bupivacaine 7.5 mg and 20 μg fentanyl provides adequate spinal anesthesia for laparoscopy and, in comparison with hyperbaric bupivacaine 15% and fentanyl 20 μg, causes markedly less hypotension. The low-dose strategy may have an advantage in ambulatory patients because of the earlier recovery of motor and sensory function and earlier discharge. PMID:22915892

Anesthesia for Patients With Liver Disease

PubMed Central

Rahimzadeh, Poupak; Safari, Saeid; Faiz, Seyed Hamid Reza; Alavian, Seyed Moayed

2014-01-01

Context: Liver plays an important role in metabolism and physiological homeostasis in the body. This organ is unique in its structure and physiology. So it is necessary for an anesthesiologist to be familiar with various hepatic pathophysiologic conditions and consequences of liver dysfunction. Evidence Acquisition: We searched MEDLINE (Pub Med, OVID, MD Consult), SCOPUS and the Cochrane database for the following keywords: liver disease, anesthesia and liver disease, regional anesthesia in liver disease, epidural anesthesia in liver disease and spinal anesthesia in liver disease, for the period of 1966 to 2013. Results: Although different anesthetic regimens are available in modern anesthesia world, but anesthetizing the patients with liver disease is still really tough. Spinal or epidural anesthetic effects on hepatic blood flow and function is not clearly investigated, considering both the anesthetic drug-induced changes and outcomes. Regional anesthesia might be used in patients with advanced liver disease. In these cases lower drug dosages are used, considering the fact that locally administered drugs have less systemic effects. In case of general anesthesia it seems that using inhalation agents (Isoflurane, Desflurane or Sevoflurane), alone or in combination with small doses of fentanyl can be considered as a reasonable regimen. When administering drugs, anesthetist must realize and consider the substantially changed pharmacokinetics of some other anesthetic drugs. Conclusions: Despite the fact that anesthesia in chronic liver disease is a scary and pretty challenging condition for every anesthesiologist, this hazard could be diminished by meticulous attention on optimizing the patient’s condition preoperatively and choosing appropriate anesthetic regimen and drugs in this setting. Although there are paucity of statistics and investigations in this specific group of patients but these little data show that with careful monitoring and considering the above mentioned rules a safe anesthesia could be achievable in these patients. PMID:25031586

Anesthesia management of surgery for sigmoid perforation and acute peritonitis patient following heart transplantation: case report

PubMed Central

Yang, Xu-Li; Dai, Shu-Hong; Zhang, Juan; Zhang, Jing; Liu, Yan-Jun; Yang, Yan; Sun, Yu-E; Ma, Zheng-Liang; Gu, Xiao-Ping

2015-01-01

Here we described a case in which a patient underwent emergency laparotomy for acute peritonitis and sigmoid perforation under general anesthesia with a history of heart transplantation. A good knowledge in the physiology of the transplanted heart is critical for effective and safe general anesthesia. We chose etomidate that have a weaker impact on cardiovascular function plus propofol for induction, and propofol plus cisatracurium for maintenance with intermittently analgesics and vasoactive drugs to facilitate the anesthesia. In addition, fluid input, electrolyte and acid-base balance were well adjusted during the whole procedure. The patient was in good condition after the surgery. In this case report we are aiming to provide some guidance for those scheduled for non-cardiac surgery after heart transplant. PMID:26379997

EEG slow-wave coherence changes in propofol-induced general anesthesia: experiment and theory

PubMed Central

Wang, Kaier; Steyn-Ross, Moira L.; Steyn-Ross, D. A.; Wilson, Marcus T.; Sleigh, Jamie W.

2014-01-01

The electroencephalogram (EEG) patterns recorded during general anesthetic-induced coma are closely similar to those seen during slow-wave sleep, the deepest stage of natural sleep; both states show patterns dominated by large amplitude slow waves. Slow oscillations are believed to be important for memory consolidation during natural sleep. Tracking the emergence of slow-wave oscillations during transition to unconsciousness may help us to identify drug-induced alterations of the underlying brain state, and provide insight into the mechanisms of general anesthesia. Although cellular-based mechanisms have been proposed, the origin of the slow oscillation has not yet been unambiguously established. A recent theoretical study by Steyn-Ross et al. (2013) proposes that the slow oscillation is a network, rather than cellular phenomenon. Modeling anesthesia as a moderate reduction in gap-junction interneuronal coupling, they predict an unconscious state signposted by emergent low-frequency oscillations with chaotic dynamics in space and time. They suggest that anesthetic slow-waves arise from a competitive interaction between symmetry-breaking instabilities in space (Turing) and time (Hopf), modulated by gap-junction coupling strength. A significant prediction of their model is that EEG phase coherence will decrease as the cortex transits from Turing–Hopf balance (wake) to Hopf-dominated chaotic slow-waves (unconsciousness). Here, we investigate changes in phase coherence during induction of general anesthesia. After examining 128-channel EEG traces recorded from five volunteers undergoing propofol anesthesia, we report a significant drop in sub-delta band (0.05–1.5 Hz) slow-wave coherence between frontal, occipital, and frontal–occipital electrode pairs, with the most pronounced wake-vs.-unconscious coherence changes occurring at the frontal cortex. PMID:25400558

Electromyographic activation reveals cortical and sub-cortical dissociation during emergence from general anesthesia.

PubMed

Hight, Darren F; Voss, Logan J; García, Paul S; Sleigh, Jamie W

2017-08-01

During emergence from anesthesia patients regain their muscle tone (EMG). In a typical population of surgical patients the actual volatile gas anesthetic concentrations in the brain (C e MAC) at which EMG activation occurs remains unknown, as is whether EMG activation at higher C e MACs is correlated with subsequent severe pain, or with cortical activation. Electroencephalographic (EEG) and EMG activity was recorded from the forehead of 273 patients emerging from general anesthesia following surgery. We determined C e MAC at time of EMG activation and at return of consciousness. Pain was assessed immediately after return of consciousness using an 11 point numerical rating scale. The onset of EMG activation during emergence was associated with neither discernible muscle movement nor with the presence of exogenous stimulation in half the patients. EMG activation could be modelled as two distinct processes; termed high- and low-C e MAC (occurring higher or lower than 0.07 C e MAC). Low-C e MAC activation was typically associated with simultaneous EMG activation and consciousness, and the presence of a laryngeal mask. In contrast, high-C e MAC EMG activation occurred independently of return of consciousness, and was not associated with severe post-operative pain, but was more common in the presence of an endotracheal tube. Patients emerging from general anesthesia with an endotracheal tube in place are more likely to have an EMG activation at higher C e MAC concentrations. These activations are not associated with subsequent high-pain, nor with cortical arousal, as evidenced by continuing delta waves in the EEG. Conversely, patients emerging from general anesthesia with a laryngeal mask demonstrate marked neural inertia-EMG activation occurs at a low C e MAC, and is closely temporally associated with return of consciousness.

Influence of clove oil and eugenol on muscle contraction of silkworm (Bombyx mori).

PubMed

Kheawfu, Kantaporn; Pikulkaew, Surachai; Hamamoto, Hiroshi; Sekimizu, Kazuhisa; Okonogi, Siriporn

2017-05-30

Clove oil is used in fish anesthesia and expected to have a mechanism via glutamic receptor. The present study explores the activities of clove oil and its major compound, eugenol, in comparison with L-glutamic acid on glutamic receptor of silkworm muscle and fish anesthesia. It was found that clove oil and eugenol had similar effects to L-glutamic acid on inhibition of silkworm muscle contraction after treated with D-glutamic acid and kainic acid. Anesthetic activity of the test samples was investigated in goldfish. The results demonstrated that L-glutamic acid at 20 and 40 mM could induce the fish to stage 3 of anesthesia that the fish exhibited total loss of equilibrium and muscle tone, whereas clove oil and eugenol at 60 ppm could induce the fish to stage 4 of anesthesia that the reflex activity of the fish was lost. These results suggest that clove oil and eugenol have similar functional activities and mechanism to L-glutamic acid on muscle contraction and fish anesthesia.

[The research on a pocket microcontroller system for target controlled infusion].

PubMed

Cheng, Yu-Ke; Zhang, Xin-An; Zhang, Yan-Wu; Wu, Qun-Ling; Dou, Jian-Hong; Wang, Rou-Shong

2005-05-01

This paper present a microcontroller system for target controlled infusion according to pharmacodynamic parameters of intravenous anesthetics. It can control the depth of anesthesia by adjusting the level of plasma concentrations. The system has the advantages of high precision, extended function and easy operation. It has been now used in the clinical anesthesia.

Anesthesia and bariatric surgery gut preparation alter plasma acylcarnitines reflective of mitochondrial fat and branched-chain amino acid oxidation

USDA-ARS?s Scientific Manuscript database

The period around bariatric surgery offers a unique opportunity to characterize metabolism responds to dynamic shifts in energy, gut function, and anesthesia. We analyzed plasma acylcarnitines in obese women (n=17) sampled in the overnight fasted/postabsorptive state ca. 1-2 weeks prior to surgery ...

Animal Model Selection for Inhalational HCN Exposure

DTIC Science & Technology

2016-08-01

temperature and pressure). Health Effects from CN Exposure Cardiovascular responses to CN are complex and include precordial pain and EKG abnormalities...thyroid) may be affected, the brain is selectively sensitive given its high oxygen consumption and low rhodanese content, an enzyme involved in CN...efficiency of oxygenation while in dorsal recumbency under anesthesia, is decreased slightly compared to humans. The alveolar ventilation and perfusion (VA/Q

Perinatal supplementation with omega-3 polyunsaturated fatty acids improves sevoflurane-induced neurodegeneration and memory impairment in neonatal rats.

PubMed

Lei, Xi; Zhang, Wenting; Liu, Tengyuan; Xiao, Hongyan; Liang, Weimin; Xia, Weiliang; Zhang, Jun

2013-01-01

To investigate if perinatal Omega-3 polyunsaturated fatty acids (n-3 PUFAs) supplementation can improve sevoflurane-induced neurotoxicity and cognitive impairment in neonatal rats. Female Sprague-Dawley rats (n = 3 each group) were treated with or without an n-3 PUFAs (fish oil) enriched diet from the second day of pregnancy to 14 days after parturition. The offspring rats (P7) were treated with six hours sevoflurane administration (one group without sevoflurane/prenatal n-3 PUFAs supplement as control). The 5-bromodeoxyuridine (Brdu) was injected intraperitoneally during and after sevoflurane anesthesia to assess dentate gyrus (DG) progenitor proliferation. Brain tissues were harvested and subjected to Western blot and immunohistochemistry respectively. Morris water maze spatial reference memory, fear conditioning, and Morris water maze memory consolidation were tested at P35, P63 and P70 (n = 9), respectively. Six hours 3% sevoflurane administration increased the cleaved caspase-3 in the thalamus, parietal cortex but not hippocampus of neonatal rat brain. Sevoflurane anesthesia also decreased the neuronal precursor proliferation of DG in rat hippocampus. However, perinatal n-3 PUFAs supplement could decrease the cleaved caspase-3 in the cerebral cortex of neonatal rats, and mitigate the decrease in neuronal proliferation in their hippocampus. In neurobehavioral studies, compared with control and n-3 PUFAs supplement groups, we did not find significant spatial cognitive deficit and early long-term memory impairment in sevoflurane anesthetized neonatal rats at their adulthood. However, sevoflurane could impair the immediate fear response and working memory and short-term memory. And n-3 PUFAs could improve neurocognitive function in later life after neonatal sevoflurane exposure. Our study demonstrated that neonatal exposure to prolonged sevoflurane could impair the immediate fear response, working memory and short-term memory of rats at their adulthood, which may through inducing neuronal apoptosis and decreasing neurogenesis. However, these sevoflurane-induced unfavorable neuronal effects can be mitigated by perinatal n-3 PUFAs supplementation.

SU-F-T-668: Irradiating Mouse Brain with a Clinical Linear Accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perez-Torres, C

Purpose: To design and construct a “mouse jig” device that would allow for irradiation of the mouse brain with a clinical Varian 6 MeV Linear Accelerator. This device must serve as a head immobilizer, gaseous anesthesia delivery, and radiation bolus concurrently. Methods: The mouse jig was machined out of nylon given that it is inexpensive, easy to machine, and has similar electron density to water. A cylindrical opening with diameter of 16 mm and 40 mm depth was drilled into a nylon block sized 56×56×50 mm (width, length, depth). Additional slots were included in the block for ear bars andmore » a tooth bar to serve as a three-point immobilization device as well as for anesthesia delivery and scavenging. For ease of access when loading the mouse into the holder, there is a removable piece at the top of the block that is 15 mm in depth. This serves a dual purpose, as with the proper extra shielding, the mouse jig could be used with lower linear energy transfer photons with this piece removed. A baseplate was then constructed with five square slots where the mouse jig can securely be inserted plus additional slots that would allow the baseplate to be mounted on a standard lock bar in the treatment couch. This maximizes the reproducibility of placement between imaging and treatment and between treatment sessions. Results: CT imaging and radiation treatment planning was performed that showed acceptable coverage and uniformity of radiation dose in the mouse brain while sparing the throat and eyes. Conclusion: We have designed and manufactured a device that fulfills our criteria allowing us to selectively irradiate the mouse brain with a clinical linear accelerator. This setup will be used for generating mouse models of radiation-induced brain injury.« less

Anesthesia and kidney transplantation.

PubMed

Ricaurte, L; Vargas, J; Lozano, E; Díaz, L

2013-05-01

Chronic kidney disease (CKD) has diverse causes and the outcomes can change with renal transplantation, which has the potential to increase quality of life and improve survival. Because transplant recipients usually have comorbid conditions, presurgical assessment, optimization of health status, monitoring, and intraoperative anesthetic management are essential. The objective of this study was to evaluate available medical literature concerning presurgical anesthetic assessment and intraoperative and postoperative anesthetic management of patients undergoing renal transplantation. REVIEW CRITERIA: A bibliographic search was made in MEDLINE, OVID, and LILIACS without language or design limits. Available evidence from February 1991 to February 2011 was taken. Articles about anesthesia in renal transplantation were included. Information quality was assessed according to design type with "Critical Appraisal Skills Program" (CASP-UK) tools. Epidemiological data in Colombia were obtained from the Social Protection Ministry and FOSYGA (Solidarity and Guarantee Fund) web pages. Regarding prognosis, CKD mortality increases with dialysis and with its duration, whereas transplantation reduces it and enhances survival. Recipient mortality, functionality, and graft lifespan are influenced by donor type (immediate diuresis with living donors, P < .05), hydration (60-90 mL/kg), early diuresis (13% mortality rate at 1 year if delayed and reduction of graft lifetime 20%-40%). When comparing diuresis, clearance creatinine, kidney perfusion, and function, there were no significant differences between general and regional anesthesia. Nevertheless, postoperative analgesia was better with epidural anesthesia. Examination of the patient and optimization of the overall health status contributes to graft optimal function and patient survival. Regional anesthesia has better control over postoperative pain, but it has no effect on the prognosis, The intraoperative maintenance of appropriate hydration enhances flux and renal perfusion, which allows early functionality of the graft. This, together with a living donor are considered good prognosis factors, moreover they reduce recipient mortality and improve graft lifetime. Copyright © 2013 Elsevier Inc. All rights reserved.

Electrophysiologic Study of a Method of Euthanasia Using Intrathecal Lidocaine Hydrochloride Administered during Intravenous Anesthesia in Horses.

PubMed

Aleman, M; Davis, E; Williams, D C; Madigan, J E; Smith, F; Guedes, A

2015-01-01

An intravenous (IV) overdose of pentobarbital sodium is the most commonly used method of euthanasia in veterinary medicine. However, this compound is not available in many countries or rural areas resulting in usage of alternative methods such as intrathecal lidocaine administration after IV anesthesia. Its safety and efficacy as a method of euthanasia have not been investigated in the horse. To investigate changes in mean arterial blood pressure and electrical activity of the cerebral cortex, brainstem, and heart during intrathecal administration of lidocaine. Our hypothesis was that intrathecal lidocaine affects the cerebral cortex and brainstem before affecting cardiovascular function. Eleven horses requiring euthanasia for medical reasons. Prospective observational study. Horses were anesthetized with xylazine, midazolam, and ketamine; and instrumented for recording of electroencephalogram (EEG), electrooculogram (EOG), brainstem auditory evoked response (BAER), and electrocardiogram (ECG). Physical and neurological (brainstem reflexes) variables were monitored. Mean arterial blood pressure was recorded throughout the study. Loss of cerebro-cortical electrical activity occurred up to 226 seconds after the end of the infusion of lidocaine solution. Cessation of brainstem function as evidenced by a lack of brainstem reflexes and disappearance of BAER occurred subsequently. Undetectable heart sounds, nonpalpable arterial pulse, and extremely low mean arterial blood pressure supported cardiac death; a recordable ECG was the last variable to disappear after the infusion (300-1,279 seconds). Intrathecal administration of lidocaine is an effective alternative method of euthanasia in anesthetized horses, during which brain death occurs before cardiac death. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of American College of Veterinary Internal Medicine.

Neurophysiology of hypnosis.

PubMed

Vanhaudenhuyse, A; Laureys, S; Faymonville, M-E

2014-10-01

We here review behavioral, neuroimaging and electrophysiological studies of hypnosis as a state, as well as hypnosis as a tool to modulate brain responses to painful stimulations. Studies have shown that hypnotic processes modify internal (self awareness) as well as external (environmental awareness) brain networks. Brain mechanisms underlying the modulation of pain perception under hypnotic conditions involve cortical as well as subcortical areas including anterior cingulate and prefrontal cortices, basal ganglia and thalami. Combined with local anesthesia and conscious sedation in patients undergoing surgery, hypnosis is associated with improved peri- and postoperative comfort of patients and surgeons. Finally, hypnosis can be considered as a useful analogue for simulating conversion and dissociation symptoms in healthy subjects, permitting better characterization of these challenging disorders by producing clinically similar experiences. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Renal function following xenon anesthesia for partial nephrectomy-An explorative analysis of a randomized controlled study.

PubMed

Stevanovic, Ana; Schaefer, Patrick; Coburn, Mark; Rossaint, Rolf; Stoppe, Christian; Boor, Peter; Pfister, David; Heidenreich, Axel; Christ, Hildegard; Hellmich, Martin; Fahlenkamp, Astrid V

2017-01-01

Perioperative preservation of renal function has a significant impact on morbidity and mortality in kidney surgery. Nephroprotective effects of the anesthetic xenon on ischemia-reperfusion injury were found in several experimental studies. We aimed to explore whether xenon anesthesia can reduce renal damage in humans undergoing partial nephrectomy and to gather pilot data of possible nephroprotection in these patients. A prospective randomized, single-blinded, controlled study. Single-center, University Hospital of Aachen, Germany between July 2013-October 2015. Forty-six patients with regular renal function undergoing partial nephrectomy. Patients were randomly assigned to receive xenon- (n = 23) or isoflurane (n = 23) anesthesia. Primary outcome was the maximum postoperative glomerular filtration rate (GFR) decline within seven days after surgery. Secondary outcomes included intraoperative and tumor-related data, assessment of further kidney injury markers, adverse events and optional determination of renal function after 3-6 months. Unexpected radical nephrectomy was performed in 5 patients, thus they were excluded from the per-protocol analysis, but included in the intention-to-treat analysis. The maximum postoperative GFR decline was attenuated by 45% in the xenon-group (10.9 ml min-1 1.73 cm-2 versus 19.7 ml min-1 1.73 cm-2 in the isoflurane group), but without significance (P = 0.084). Occurrence of adverse events was reduced (P = 0.003) in the xenon group. Renal function was similar among the groups after 3-6 months. Xenon anesthesia was feasible and safe in patients undergoing partial nephrectomy with regard to postoperative renal function. We found no significant effect on early renal function but less adverse events in the xenon group. Larger randomized controlled studies in more heterogeneous collectives are required, to confirm or refute the possible clinical benefit on renal function by xenon. ClinicalTrials.gov NCT01839084 and EudraCT 2012-005698-30.

Circuit Analysis of a Drosophila Dopamine Type 2 Receptor That Supports Anesthesia-Resistant Memory.

PubMed

Scholz-Kornehl, Sabrina; Schwärzel, Martin

2016-07-27

Dopamine is central to reinforcement processing and exerts this function in species ranging from humans to fruit flies. It can do so via two different types of receptors (i.e., D1 or D2) that mediate either augmentation or abatement of cellular cAMP levels. Whereas D1 receptors are known to contribute to Drosophila aversive odor learning per se, we here show that D2 receptors are specific for support of a consolidated form of odor memory known as anesthesia-resistant memory. By means of genetic mosaicism, we localize this function to Kenyon cells, the mushroom body intrinsic neurons, as well as GABAergic APL neurons and local interneurons of the antennal lobes, suggesting that consolidated anesthesia-resistant memory requires widespread dopaminergic modulation within the olfactory circuit. Additionally, dopaminergic neurons themselves require D2R, suggesting a critical role in dopamine release via its recognized autoreceptor function. Considering the dual role of dopamine in balancing memory acquisition (proactive function of dopamine) and its "forgetting" (retroactive function of dopamine), our analysis suggests D2R as central player of either process. Dopamine provides different information; while it mediates reinforcement during the learning act (proactive function), it balances memory performance between two antithetic processes thereafter (retroactive function) (i.e., forgetting and augmentation). Such bidirectional design can also be found at level of dopamine receptors, where augmenting D1 and abating D2 receptors are engaged to balance cellular cAMP levels. Here, we report that consolidated anesthesia-resistant memory (ARM), but not other concomitant memory phases, are sensitive to bidirectional dopaminergic signals. By means of genetic mosaicism, we identified widespread dopaminergic modulation within the olfactory circuit that suggests nonredundant and reiterating functions of D2R in support of ARM. Our results oppose ARM to its concomitant memory phases that localize to mushroom bodies and propose a decentralized organization of consolidated ARM. Copyright © 2016 the authors 0270-6474/16/367936-10$15.00/0.

HYPNOTIC TACTILE ANESTHESIA: Psychophysical and Signal-Detection Analyses

PubMed Central

Tataryn, Douglas J.; Kihlstrom, John F.

2017-01-01

Two experiments that studied the effects of hypnotic suggestions on tactile sensitivity are reported. Experiment 1 found that suggestions for anesthesia, as measured by both traditional psychophysical methods and signal detection procedures, were linearly related to hypnotizability. Experiment 2 employed the same methodologies in an application of the real-simulator paradigm to examine the effects of suggestions for both anesthesia and hyperesthesia. Significant effects of hypnotic suggestion on both sensitivity and bias were found in the anesthesia condition but not for the hyperesthesia condition. A new bias parameter, C′, indicated that much of the bias found in the initial analyses was artifactual, a function of changes in sensitivity across conditions. There were no behavioral differences between reals and simulators in any of the conditions, though analyses of postexperimental interviews suggested the 2 groups had very different phenomenal experiences. PMID:28230465

Local infiltration anesthesia with steroids in total knee arthroplasty: A systematic review of randomized control trials.

PubMed

Tran, Jonathan; Schwarzkopf, Ran

2015-10-01

Local infiltration anesthesia (LIA) with anesthetics, steroids, NSAIDS, and epinephrine has been shown to be effective in reducing total knee arthroplasty (TKA) postoperative pain. This systematic review explores the functional outcomes of randomized control trials that have compared the use of LIA with and without steroids during TKA. Five studies with 412 patients met the inclusion criteria, 228 received local infiltration anesthesia with steroids (LIAS) and 184 received local infiltration anesthesia without steroids (LIAWS). The use of LIAS in management of postoperative TKA pain has been shown to decrease the length of hospital stay, time required to achieve straight leg raise, and pro-inflammatory signals in patients. Although there is no overwhelming data to suggest LIAS improves postoperative TKA pain, current literature does support its effectiveness in producing other favorable surgical outcomes.

World Health Organization-World Federation of Societies of Anaesthesiologists (WHO-WFSA) International Standards for a Safe Practice of Anesthesia.

PubMed

Gelb, Adrian W; Morriss, Wayne W; Johnson, Walter; Merry, Alan F; Abayadeera, Anuja; Belîi, Natalia; Brull, Sorin J; Chibana, Aline; Evans, Faye; Goddia, Cyril; Haylock-Loor, Carolina; Khan, Fauzia; Leal, Sandra; Lin, Nan; Merchant, Richard; Newton, Mark W; Rowles, Jackie S; Sanusi, Arinola; Wilson, Iain; Velazquez Berumen, Adriana

2018-06-01

The International Standards for a Safe Practice of Anesthesia were developed on behalf of the World Federation of Societies of Anaesthesiologists (WFSA), a nonprofit organization representing anesthesiologists in 150 countries, and the World Health Organization (WHO). The recommendations have been approved by WHO and the membership of WFSA. These Standards are applicable to all anesthesia providers throughout the world. They are intended to provide guidance and assistance to anesthesia providers, their professional organizations, hospital and facility administrators, and governments for maintaining and improving the quality and safety of anesthesia care. The Standards cover professional aspects; facilities and equipment; medications and intravenous fluids; monitoring; and the conduct of anesthesia. HIGHLY RECOMMENDED standards, the functional equivalent of mandatory standards, include (amongst other things): the continuous presence of a trained and vigilant anesthesia provider; continuous monitoring of tissue oxygenation and perfusion by clinical observation and a pulse oximeter; intermittent monitoring of blood pressure; confirmation of correct placement of an endotracheal tube (if used) by auscultation and carbon dioxide detection; the use of the WHO Safe Surgery Checklist; and a system for transfer of care at the end of an anesthetic. The International Standards represent minimum standards and the goal should always be to practice to the highest possible standards, preferably exceeding the standards outlined in this document.

World Health Organization-World Federation of Societies of Anaesthesiologists (WHO-WFSA) International Standards for a Safe Practice of Anesthesia.

PubMed

Gelb, Adrian W; Morriss, Wayne W; Johnson, Walter; Merry, Alan F

2018-05-07

The International Standards for a Safe Practice of Anesthesia were developed on behalf of the World Federation of Societies of Anaesthesiologists (WFSA), a non-profit organization representing anesthesiologists in 150 countries, and the World Health Organization (WHO). The recommendations have been approved by WHO and the membership of WFSA. These Standards are applicable to all anesthesia providers throughout the world. They are intended to provide guidance and assistance to anesthesia providers, their professional organizations, hospital and facility administrators, and governments for maintaining and improving the quality and safety of anesthesia care. The Standards cover professional aspects; facilities and equipment; medications and intravenous fluids; monitoring; and the conduct of anesthesia. HIGHLY RECOMMENDED standards, the functional equivalent of mandatory standards, include (amongst other things): the continuous presence of a trained and vigilant anesthesia provider; continuous monitoring of tissue oxygenation and perfusion by clinical observation and a pulse oximeter; intermittent monitoring of blood pressure; confirmation of correct placement of an endotracheal tube (if used) by auscultation and carbon dioxide detection; the use of the WHO Safe Surgery Checklist; and a system for transfer of care at the end of an anesthetic. The International Standards represent minimum standards and the goal should always be to practice to the highest possible standards, preferably exceeding the standards outlined in this document.

Anesthesia and concussion.

PubMed

Tasker, Robert C

2017-06-01

As clinicians preparing patients for general anesthesia, should we consider the possibility of concussion in our elective operative patients? If so, why is this necessary? Is it possible that exposure to an anesthetic is detrimental to recovery from concussion? If so, what should we do about the imperative/urgency for surgery? No answers are promised in this review. Rather, the focus is on the questions and approaches taken in the recent literature, as well as highlighting a need for more research. Surgery, pain and general anesthesia all influence autonomic nervous system responses. Intravenous and inhalational anesthetic agents are also known to have variable effects on the cerebrovascular reactivity (CVR) to carbon dioxide (CO2). This review adds to this general information the recent, specific physiologic alterations seen after concussion in autonomic system function and the CVR to CO2. This review provides a perspective about autonomic nervous system function and cerebrovascular effects of concussion, and some relevant clinical issues that warrant further clinical study.

Ammonia encephalopathy and awake craniotomy for brain language mapping: cause of failed awake craniotomy.

PubMed

Villalba Martínez, G; Fernández-Candil, J L; Vivanco-Hidalgo, R M; Pacreu Terradas, S; León Jorba, A; Arroyo Pérez, R

2015-05-01

We report the case of an aborted awake craniotomy for a left frontotemporoinsular glioma due to ammonia encephalopathy on a patient taking Levetiracetam, valproic acid and clobazam. This awake mapping surgery was scheduled as a second-stage procedure following partial resection eight days earlier under general anesthesia. We planned to perform the surgery with local anesthesia and sedation with remifentanil and propofol. After removal of the bone flap all sedation was stopped and we noticed slow mentation and excessive drowsiness prompting us to stop and control the airway and proceed with general anesthesia. There were no post-operative complications but the patient continued to exhibit bradypsychia and hand tremor. His ammonia level was found to be elevated and was treated with an infusion of l-carnitine after discontinuation of the valproic acid with vast improvement. Ammonia encephalopathy should be considered in patients treated with valproic acid and mental status changes who require an awake craniotomy with patient collaboration. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Nonopioid anesthesia for awake craniotomy: a case report.

PubMed

Wolff, Diane L; Naruse, Robert; Gold, Michele

2010-02-01

Awake craniotomy is becoming more popular as a neurosurgical technique that allows for increased tumor resection and decreased postoperative neurologic morbidity. This technique, however, presents many challenges to both the neurosurgeon and anesthetist. An ASA class II, 37-year-old man with recurrent oligodendroglioma presented for repeated craniotomy. Prior craniotomy under general anesthesia resulted in residual neurologic deficits. An awake craniotomy was planned to allow for intraoperative testing for maximum tumor resection and avoidance of neurologic morbidity. The patient was sedated with propofol, and bupivacaine was infiltrated for placement of Mayfield tongs and skin incision. Following exposure of brain tissue, propofol infusion was discontinued to allow for patient cooperation during the procedure. Speech, motor, and sensory testing occurred during tumor resection until resection stopped after onset of weakness in the right arm. The propofol infusion was resumed while the cranium was closed and Mayfield tongs removed. The patient was awake, alert, oriented, and able to move all extremities but had residual weakness in the right forearm. Awake craniotomy requires appropriate patient selection, knowledge of the surgeon's skill, and a thorough anesthesia plan. This case report discusses the clinical and anesthetic management for awake craniotomy and reviews the literature.

[Anesthesiological management of awake craniotomy : Asleep-awake-asleep technique or without sedation].

PubMed

Seemann, M; Zech, N; Graf, B; Hansen, E

2015-02-01

Awake craniotomy is indicated in deep brain stimulation (DBS) for treatment of certain movement disorders, such as in Parkinson disease patients or in the surgery of brain tumors in close vicinity to the language area. The standard procedure is the asleep-awake-asleep technique where general anesthesia or analgosedation is intermittently interrupted for neurological testing. In DBS the intraoperative improvement of symptoms, stereotactic navigation and microelectrode reading guide to the optimal position. In brain tumor resection, reversible functional impairments during electrical stimulation on the brain surface (brain mapping) show the exact individual position of eloquent or motoric areas that should be protected.The anesthesiology procedures used are very variable. It is a balancing act between overdosing of anesthetics with impairment of respiration and alertness and underdosing with pain, strain and stress for the patient. For the asleep-awake-asleep technique high acceptance but also frequent and partly severe complications have been reported. The psychological stress for the patient can be immense. Obviously, a feeling of being left alone and being at someone's mercy is not adequately treated by drugs and performance of the neurological tests is undoubtedly better and more reliable with less pharmacological impairment. Cranial nerve blocks can reduce the amount of anesthetics as they provide analgesia of the scalp more efficiently than local infiltration. With these nerve blocks, a strong therapeutic relationship and a specific communication, sedatives can be avoided and the need for opioids markedly reduced or abolished. The suggestive communication promotes for instance dissociation to an inner safe refuge, as well as reframing of disturbing noises and sensations. Each of the methods applied for awake craniotomy can profit from the principles of this awake-awake-awake technique.

The Effect of Body Posture on Brain Glymphatic Transport.

PubMed

Lee, Hedok; Xie, Lulu; Yu, Mei; Kang, Hongyi; Feng, Tian; Deane, Rashid; Logan, Jean; Nedergaard, Maiken; Benveniste, Helene

2015-08-05

The glymphatic pathway expedites clearance of waste, including soluble amyloid β (Aβ) from the brain. Transport through this pathway is controlled by the brain's arousal level because, during sleep or anesthesia, the brain's interstitial space volume expands (compared with wakefulness), resulting in faster waste removal. Humans, as well as animals, exhibit different body postures during sleep, which may also affect waste removal. Therefore, not only the level of consciousness, but also body posture, might affect CSF-interstitial fluid (ISF) exchange efficiency. We used dynamic-contrast-enhanced MRI and kinetic modeling to quantify CSF-ISF exchange rates in anesthetized rodents' brains in supine, prone, or lateral positions. To validate the MRI data and to assess specifically the influence of body posture on clearance of Aβ, we used fluorescence microscopy and radioactive tracers, respectively. The analysis showed that glymphatic transport was most efficient in the lateral position compared with the supine or prone positions. In the prone position, in which the rat's head was in the most upright position (mimicking posture during the awake state), transport was characterized by "retention" of the tracer, slower clearance, and more CSF efflux along larger caliber cervical vessels. The optical imaging and radiotracer studies confirmed that glymphatic transport and Aβ clearance were superior in the lateral and supine positions. We propose that the most popular sleep posture (lateral) has evolved to optimize waste removal during sleep and that posture must be considered in diagnostic imaging procedures developed in the future to assess CSF-ISF transport in humans. The rodent brain removes waste better during sleep or anesthesia compared with the awake state. Animals exhibit different body posture during the awake and sleep states, which might affect the brain's waste removal efficiency. We investigated the influence of body posture on brainwide transport of inert tracers of anesthetized rodents. The major finding of our study was that waste, including Aβ, removal was most efficient in the lateral position (compared with the prone position), which mimics the natural resting/sleeping position of rodents. Although our finding awaits testing in humans, we speculate that the lateral position during sleep has advantage with regard to the removal of waste products including Aβ, because clinical studies have shown that sleep drives Aβ clearance from the brain. Copyright © 2015 the authors 0270-6474/15/3511034-11$15.00/0.

The Effect of Body Posture on Brain Glymphatic Transport

PubMed Central

Lee, Hedok; Xie, Lulu; Yu, Mei; Kang, Hongyi; Feng, Tian; Deane, Rashid; Logan, Jean; Nedergaard, Maiken

2015-01-01

The glymphatic pathway expedites clearance of waste, including soluble amyloid β (Aβ) from the brain. Transport through this pathway is controlled by the brain's arousal level because, during sleep or anesthesia, the brain's interstitial space volume expands (compared with wakefulness), resulting in faster waste removal. Humans, as well as animals, exhibit different body postures during sleep, which may also affect waste removal. Therefore, not only the level of consciousness, but also body posture, might affect CSF–interstitial fluid (ISF) exchange efficiency. We used dynamic-contrast-enhanced MRI and kinetic modeling to quantify CSF-ISF exchange rates in anesthetized rodents' brains in supine, prone, or lateral positions. To validate the MRI data and to assess specifically the influence of body posture on clearance of Aβ, we used fluorescence microscopy and radioactive tracers, respectively. The analysis showed that glymphatic transport was most efficient in the lateral position compared with the supine or prone positions. In the prone position, in which the rat's head was in the most upright position (mimicking posture during the awake state), transport was characterized by “retention” of the tracer, slower clearance, and more CSF efflux along larger caliber cervical vessels. The optical imaging and radiotracer studies confirmed that glymphatic transport and Aβ clearance were superior in the lateral and supine positions. We propose that the most popular sleep posture (lateral) has evolved to optimize waste removal during sleep and that posture must be considered in diagnostic imaging procedures developed in the future to assess CSF-ISF transport in humans. SIGNIFICANCE STATEMENT The rodent brain removes waste better during sleep or anesthesia compared with the awake state. Animals exhibit different body posture during the awake and sleep states, which might affect the brain's waste removal efficiency. We investigated the influence of body posture on brainwide transport of inert tracers of anesthetized rodents. The major finding of our study was that waste, including Aβ, removal was most efficient in the lateral position (compared with the prone position), which mimics the natural resting/sleeping position of rodents. Although our finding awaits testing in humans, we speculate that the lateral position during sleep has advantage with regard to the removal of waste products including Aβ, because clinical studies have shown that sleep drives Aβ clearance from the brain. PMID:26245965

Isoflurane prevents neurocognitive dysfunction after cardiopulmonary bypass in rats.

PubMed

Li, Wen; Zheng, Beijie; Xu, Huan; Deng, Yuxiao; Wang, Shuyan; Wang, Xiangrui; Su, Diansan

2013-06-01

Postoperative cognitive dysfunction occurs frequently after cardiac surgeries with cardiopulmonary bypass (CPB). Available data from rat CPB models are conflicting. However, none of them was designed to investigate the role of isoflurane (the main anesthetic in all of these studies) in the neurocognitive dysfunction after CPB. Isoflurane has documented neuroprotective effects so the present authors hypothesized that isoflurane prevents the neurocognitive dysfunction in rats after CPB. A prospective, interventional study. A university research laboratory. Male Sprague-Dawley rats. Male Sprague-Dawley rats were divided into 5 groups: the isoflurane CPB group, the animals were anesthetized with isoflurane and underwent 60 minutes of normothermic CPB; the chloral hydrate CPB group, the animals were anesthetized with chloral hydrate and underwent 60 minutes of normothermic CPB; the isoflurane sham group, the animals were subjected only to cannulation and the same duration of anesthesia but no CPB; the chloral hydrate sham group, the animals received only cannulation and the same duration of anesthesia but no CPB; and the naive group, the animals received no treatment. The neurocognitive function of all rats was measured on days 4 to 6 (short-term) and 31 to 33 after CPB (long-term). After the behavior tests, the animals were sacrificed, and the brain was harvested for the measurement of acetylcholinesterase (AChE) and choline acetyltransferase protein levels. Short-term (days 4-6 after CPB) learning and memory were impaired after CPB when the animals were anesthetized with chloral hydrate. When isoflurane was used, the learning and memory did not change after CPB. No long-term (days 31-33 after CPB) neurocognitive changes were found after CPB. AChE decreased significantly after isoflurane anesthesia regardless of whether CPB was performed. Isoflurane prevented the neurocognitive dysfunction induced by CPB, which might involve the cerebral cholinergic system. Copyright © 2013 Elsevier Inc. All rights reserved.

Postoperative stroke after hemiarthroplasty for femoral neck fracture: a report of 2 cases and review of literature.

PubMed

Ding, David Yi; Christoforou, Dimitrios; Turner, Garth; Tejwani, Nirmal C

2014-06-01

Femoral neck fractures in the elderly comprise a significant number of orthopedic surgical cases at a major trauma center. These patients are immediately incapacitated, and surgical fixation can help increase mobility, restore independence, and reduce morbidity and mortality. However, operative treatment carries its own inherent risks including infections, deep vein thromboses, and intraoperative cardiovascular collapse. Cerebrovascular stroke is a relatively uncommon occurrence after hip fractures. We present 2 cases with unusual postoperative medical complication after cemented hip hemiarthroplasty for femoral neck fracture that will serve to illustrate an infrequent but very serious complication. Case 1 was a 73-year-old man with a Garden IV femoral neck fracture who underwent a right hip unipolar cemented hemiarthroplasty under general anesthesia. After uneventful surgery, he developed neurological deficits, and a postoperative noncontrast head computed tomography showed a right medial thalamic infarct. Case 2 was an 82-year-old man with a Garden IV femoral neck fracture who underwent a right hip unipolar cemented hemiarthroplasty under general anesthesia. After uneventful surgery, the patient became hemodynamically unstable. A postoperative noncontrast head computed tomography showed a large evolving left middle cerebral artery stroke. General anesthesia in the setting of decreased cardiac function (decreased ejection fraction and output) carries the risk for ischemic injury to the brain from decreased cerebral perfusion. Risk factors including advanced age, history of coronary artery disease, atherosclerotic disease, and atrial fibrillation increase the risk for perioperative stroke. Furthermore, it is known that during the cementing of implants, microemboli can be released, which must be considered in patients with preoperative heart disease. As a result, consideration of using a noncemented implant or cementing without pressurizing in this clinical scenario should be an important aspect of the preoperative plan in an at-risk patient. Further studies are needed that can elucidate a causal relationship.

Effect of cervical epidural blockade with 2% lidocaine plus epinephrine on respiratory function.

PubMed

Huang, Chih-Hung

2007-12-01

Cervical epidural anesthesia has been used widely for surgery of upper limbs. Although cervical epidural anesthesia with local anesthetic of 2% lidocaine (plain) has demonstrated the safety in respiratory function in spite of unavoidable phrenic and intercostal palsies to certain extent, the replacement of local anesthetics with 2% lidocaine plus epinephrine has not been investigated yet. I conducted this study to look into the effect of 2% lidocaine plus epinephrine on respiratory function. I collected data from 50 patients with mean age of 24 +/- 3 yrs, mean weight of 65 +/- 10 kg, ASA status: I-II without preoperative pulmonary dysfunction undergoing orthropedic open-reduction with internal fixation because of fractures of upper limbs. Cervical epidural space (C7-T1) was approached by hanging-drop method, using a 17G Tuohy needle. A catheter was inserted craniad to a distance of 12 cm. Pulmonary function measurement and arterial blood gas data were obstained before, 20 min, 50 min and 105 min after injection of 12 mL 2% lidocaine with 1:200,000 epinephrine. The anesthesia levels were between C3-T3 and obtained 15 +/- 2 min after injection. Mean arterial blood gas analysis showed mild respiratory acidosis at 20 min (PaCO2: 48 +/- 3 mmHg) and 50 min (PaCO2: 44 +/- 2 mmHg). The measured values of inspiratory vital capacity (IVC), vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), peak expiratory flow (PEF) when compaired with control values, were decreased about 18.0% and 12.1% of the control values at 20 min and 50 min respectively. The ratios of FEV1/VC, FEV1/FVC were still within normal limits (> 80%). The results were significantly compatible with the criteria of mild restrictive type of pulmonary function. Cervical epidural anesthesia with 2% lidocaine plus epinephrine could reduce lung volumes and capacities, resulting from partially paralytic intercostal muscles and diaphragm innervated respectively by thoracic intercostal nerve and phrenic nerve. Without inadvertant total spinal or intravenous anesthesia or pre-existing pulmonary dysfunction, the patients with normal lungs could tolerate these changes well with the procedure.

Oral health-related quality-of-life in Swedish children before and after dental treatment under general anesthesia.

PubMed

Ridell, Karin; Borgström, Margareta; Lager, Elisabeth; Magnusson, Gunilla; Brogårdh-Roth, Susanne; Matsson, Lars

2015-01-01

This study evaluated oral health-related quality-of-life (OHRQoL) in children and families before and after dental treatment under general anesthesia because of severe caries or molar-incisor hypomineralization (MIH). A consecutive sample of the parents/caregivers of children (3-14 years) in need of treatment under general anesthesia participated in the study. The children were divided into two groups: 3-6 years and 7-14 years. The 49-item questionnaire that was administered before and after general anesthesia comprised the Child Oral Health Quality of Life-components of the Parental-Caregivers Perception Questionnaire (P-CPQ), the Family Impact Scale (FIS) and two global questions concerning oral health and general well-being. The P-CPQ domains were Oral symptoms, Functional limitations, Emotional well-being and Social well-being. The FIS items assessed impact on family life. In both age groups, a significant decrease (p < 0.001) occurred in overall P-CPQ and the Oral symptoms, Functional limitations and Emotional limitations domains of the P-CPQ. Mean values for the Social well-being domain decreased significantly in the older (p < 0.05) but not the younger age group. Mean values for FIS decreased significantly in the younger (p < 0.001) and the older (p < 0.05) age groups. Dental treatment of severe caries or MIH, performed under general anesthesia, had an immediate effect on the oral health-related quality-of-life in the children in this study and a positive impact on the family situation.

Communication between anesthesiologists, patients and the anesthesia team: a descriptive study of induction and emergence.

PubMed

Smith, Andrew F; Pope, Catherine; Goodwin, Dawn; Mort, Maggie

2005-11-01

Although the importance of communication skills in anesthetic practice is increasingly recognized, formal communication skills training has hitherto dealt only with limited aspects of this professional activity. We aimed to document and analyze the informally-learned communication that takes place between anesthesia personnel and patients at induction of and emergence from general anesthesia. We adopted an ethnographic approach based principally on observation of anesthesia personnel at work in the operating theatres with subsequent analysis of observation transcripts. We noted three main styles of communication on induction, commonly combined in a single induction. In order of frequency, these were: (1) descriptive, where the anesthesiologists explained to the patient what he/she might expect to feel; (2) functional, which seemed designed to help anesthesiologists maintain physiological stability or assess the changing depth of anesthesia and (3) evocative, which referred to images or metaphors. Although the talk we have described is nominally directed at the patient, it also signifies to other members of the anesthetic team how induction is progressing. The team may also contribute to the communication behaviour depending on the context. Communication on emergence usually focused on establishing that the patient was awake. Communication at induction and emergence tends to fall into specific patterns with different emphases but similar functions. This communication work is shared across the anesthetic team. Further work could usefully explore the relationship between communication styles and team performance or indicators of patient safety or well-being.

Percutaneous Needle Tenotomy for the Treatment of Muscle and Tendon Contractures in Adults With Brain Damage: Results and Complications.

PubMed

Coroian, Flavia; Jourdan, Claire; Froger, Jérome; Anquetil, Claire; Choquet, Olivier; Coulet, Bertand; Laffont, Isabelle

2017-05-01

To study the results and complications of percutaneous needle tenotomy for superficial retracted tendons in patients with brain damage. Prospective observational study. University hospital. Patients with severe brain damage (N=38; mean age, 60.7y; age range, 24-93y; 21 women) requiring surgical management of contractures and eligible for percutaneous needle tenotomy were enrolled between February 2015 and February 2016. The percutaneous needle tenotomy gesture was performed by a physical medicine and rehabilitation physician trained by an orthopedic surgeon, under local or locoregional anesthesia. Treated tendons varied among patients. All patients were evaluated at 1, 3, and 6 months to assess surgical outcomes (joint range of motion [ROM], pain, and functional improvement) while screening for complications. Improvements in ROM (37/38) and contractures-related pain (12/12) were satisfactory. Functional results were satisfactory (Goal Attainment Scale score ≥0) for most patients (37/38): nursing (n=12), putting shoes on (n=8), getting in bed or sitting on a chair (n=6), verticalization (n=7), transfers and gait (n=8), and grip (n=2). Five patients had complications related to the surgical gesture: cast-related complications (n=2), hand hematoma (n=2), and cutaneous necrosis of the Achilles tendon in a patient with previous obliterative arteriopathy of the lower limbs (n=1). Percutaneous needle tenotomy yields good results in the management of selected superficial muscle and tendon contractures. The complications rate is very low, and this treatment can be an alternative to conventional surgery in frail patients with neurologic diseases. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Sleep facilitates clearance of metabolites from the brain: glymphatic function in aging and neurodegenerative diseases.

PubMed

Mendelsohn, Andrew R; Larrick, James W

2013-12-01

Decline of cognition and increasing risk of neurodegenerative diseases are major problems associated with aging in humans. Of particular importance is how the brain removes potentially toxic biomolecules that accumulate with normal neuronal function. Recently, a biomolecule clearance system using convective flow between the cerebrospinal fluid (CSF) and interstitial fluid (ISF) to remove toxic metabolites in the brain was described. Xie and colleagues now report that in mice the clearance activity of this so-called "glymphatic system" is strongly stimulated by sleep and is associated with an increase in interstitial volume, possibly by shrinkage of astroglial cells. Moreover, anesthesia and attenuation of adrenergic signaling can activate the glymphatic system to clear potentially toxic proteins known to contribute to the pathology of Alzheimer disease (AD) such as beta-amyloid (Abeta). Clearance during sleep is as much as two-fold faster than during waking hours. These results support a new hypothesis to answer the age-old question of why sleep is necessary. Glymphatic dysfunction may pay a hitherto unsuspected role in the pathogenesis of neurodegenerative diseases as well as maintenance of cognition. Furthermore, clinical studies suggest that quality and duration of sleep may be predictive of the onset of AD, and that quality sleep may significantly reduce the risk of AD for apolipoprotein E (ApoE) ɛ4 carriers, who have significantly greater chances of developing AD. Further characterization of the glymphatic system in humans may lead to new therapies and methods of prevention of neurodegenerative diseases. A public health initiative to ensure adequate sleep among middle-aged and older people may prove useful in preventing AD, especially in apolipoprotein E (ApoE) ɛ4 carriers.

Effects of dexmedetomidine on H-FABP, CK-MB, cTnI levels, neurological function and near-term prognosis in patients undergoing heart valve replacement.

PubMed

Wang, Zhi; Chen, Qiang; Guo, Hao; Li, Zhishan; Zhang, Jinfeng; Lv, Lei; Guo, Yongqing

2017-12-01

This study investigated the effects of dexmedetomidine on heart-type fatty acid binding protein (H-FABP), creatine kinase isoenzymes (CK-MB), and troponin I (cTnI) levels, neurological function and near-term prognosis in patients undergoing heart valve replacement. Patients undergoing heart valve replacement were randomly allocated to remifentanil anesthesia (control group, n=48) or dexmedetomidine anesthesia (observation group, n=48). Hemodynamic parameters were measured before anesthesia induction (T1), 1 min after intubation (T2), 10 min after start of surgery (T3), and on completion of surgery (T4). Levels of plasma H-FABP, CK-MB and cTnI were measured 10 min before anesthesia induction (C1), 10 min after start of surgery (C2), on completion of surgery (C3), 6 h after surgery (C4), and 24 h after surgery (C5). S100β protein and serum neuron-specific enolase (NSE) were detected 10 min before anesthesia induction (C1), and 24 h after surgery (C5). Neurological and cardiac function was evaluated 24 h after surgery. Incidence of cardiovascular adverse events was recorded for 1 year of follow-up. There were no significant differences in the average heart rate between the two groups during the perioperative period. The mean arterial pressure in the observation group was significantly lower than control group (P<0.05). Levels of H-FABP, CK-MB and cTnI at C2, C3, C4 and C5, were significantly higher than C1, but significantly lower in the observation versus control group (P<0.05). Twenty-four hours after surgery, levels of S100β and NSE in both groups were higher than those before induction (P<0.05), but significantly lower in the observation versus control group (P<0.05). Twenty-four hours after surgery, neurological function scores were better, and myocardial contractility and arrhythmia scores significantly lower in the observation versus control group (P<0.05 for all). After follow-up for 1 year, incidence of cardiovascular adverse events was significantly lower in the observation versus control group (P<0.05). Dexmedetomidine anesthesia can effectively maintain hemodynamic stability, reduce myocardial injury and the occurrence of cognitive dysfunction, and improve prognosis in patients undergoing heart valve replacement.

The Emergence of Single Neurons in Clinical Neurology

PubMed Central

Cash, Sydney S.; Hochberg, Leigh R.

2015-01-01

Summary Single neuron actions and interactions are the sine qua non of brain function, and nearly all diseases and injuries of the central nervous system trace their clinical sequelae to neuronal dysfunction or failure. Remarkably, discussion of neuronal activity is largely absent in clinical neuroscience. Advances in neurotechnology and computational capabilities, accompanied by shifts in theoretical frameworks, have led to renewed interest in the information represented by single neurons. Using direct interfaces with the nervous system, millisecond-scale information will soon be extracted from single neurons in clinical environments, supporting personalized treatment of neurologic and psychiatric disease. In this review we focus on single neuronal activity in restoring communication and motor control in patients suffering from devastating neurological injuries. We also explore the single neuron's role in epilepsy and movement disorders, surgical anesthesia, and in cognitive processes disrupted in neurodegenerative and neuropsychiatric disease. Finally, we speculate on how technological advances will revolutionize neurotherapeutics. PMID:25856488

The emergence of single neurons in clinical neurology.

PubMed

Cash, Sydney S; Hochberg, Leigh R

2015-04-08

Single neuron actions and interactions are the sine qua non of brain function, and nearly all diseases and injuries of the CNS trace their clinical sequelae to neuronal dysfunction or failure. Remarkably, discussion of neuronal activity is largely absent in clinical neuroscience. Advances in neurotechnology and computational capabilities, accompanied by shifts in theoretical frameworks, have led to renewed interest in the information represented by single neurons. Using direct interfaces with the nervous system, millisecond-scale information will soon be extracted from single neurons in clinical environments, supporting personalized treatment of neurologic and psychiatric disease. In this Perspective, we focus on single-neuronal activity in restoring communication and motor control in patients suffering from devastating neurological injuries. We also explore the single neuron's role in epilepsy and movement disorders, surgical anesthesia, and in cognitive processes disrupted in neurodegenerative and neuropsychiatric disease. Finally, we speculate on how technological advances will revolutionize neurotherapeutics. Copyright © 2015 Elsevier Inc. All rights reserved.

[(18)F]-fluorodeoxyglucose positron emission tomography of the cat brain: A feasibility study to investigate osteoarthritis-associated pain.

PubMed

Guillot, Martin; Chartrand, Gabriel; Chav, Ramnada; Rousseau, Jacques; Beaudoin, Jean-François; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Lecomte, Roger; de Guise, Jacques A; Troncy, Eric

2015-06-01

The objective of this pilot study was to investigate central nervous system (CNS) changes related to osteoarthritis (OA)-associated chronic pain in cats using [(18)F]-fluorodeoxyglucose ((18)FDG) positron emission tomography (PET) imaging. The brains of five normal, healthy (non-OA) cats and seven cats with pain associated with naturally occurring OA were imaged using (18)FDG-PET during a standardized mild anesthesia protocol. The PET images were co-registered over a magnetic resonance image of a cat brain segmented into several regions of interest. Brain metabolism was assessed in these regions using standardized uptake values. The brain metabolism in the secondary somatosensory cortex, thalamus and periaqueductal gray matter was increased significantly (P ≤ 0.005) in OA cats compared with non-OA cats. This study indicates that (18)FDG-PET brain imaging in cats is feasible to investigate CNS changes related to chronic pain. The results also suggest that OA is associated with sustained nociceptive inputs and increased activity of the descending modulatory pathways. Copyright © 2015 Elsevier Ltd. All rights reserved.

Embedded Ultrathin Cluster Electrodes for Long-Term Recordings in Deep Brain Centers

PubMed Central

Thorbergsson, Palmi Thor; Ekstrand, Joakim; Friberg, Annika; Granmo, Marcus; Pettersson, Lina M. E.; Schouenborg, Jens

2016-01-01

Neural interfaces which allow long-term recordings in deep brain structures in awake freely moving animals have the potential of becoming highly valuable tools in neuroscience. However, the recording quality usually deteriorates over time, probably at least partly due to tissue reactions caused by injuries during implantation, and subsequently micro-forces due to a lack of mechanical compliance between the tissue and neural interface. To address this challenge, we developed a gelatin embedded neural interface comprising highly flexible electrodes and evaluated its long term recording properties. Bundles of ultrathin parylene C coated platinum electrodes (N = 29) were embedded in a hard gelatin based matrix shaped like a needle, and coated with Kollicoat™ to retard dissolution of gelatin during the implantation. The implantation parameters were established in an in vitro model of the brain (0.5% agarose). Following a craniotomy in the anesthetized rat, the gelatin embedded electrodes were stereotactically inserted to a pre-target position, and after gelatin dissolution the electrodes were further advanced and spread out in the area of the subthalamic nucleus (STN). The performance of the implanted electrodes was evaluated under anesthesia, during 8 weeks. Apart from an increase in the median-noise level during the first 4 weeks, the electrode impedance and signal-to-noise ratio of single-units remained stable throughout the experiment. Histological postmortem analysis confirmed implantation in the area of STN in most animals. In conclusion, by combining novel biocompatible implantation techniques and ultra-flexible electrodes, long-term neuronal recordings from deep brain structures with no significant deterioration of electrode function were achieved. PMID:27159159

Rehabilitation of arm function after stroke. Literature review.

PubMed

Oujamaa, L; Relave, I; Froger, J; Mottet, D; Pelissier, J-Y

2009-04-01

In the recent literature we can find many articles dealing with upper extremity rehabilitation in stroke patients. New techniques, still under evaluation, are becoming the practical applications for the concept of post-stroke brain plasticity. This literature review focuses on controlled randomized studies, reviews and meta-analyses published in the English language from 2004 to 2008. The research was conducted in MEDLINE with the following keywords: "upper limb", "stroke", "rehabilitation". We reviewed 66 studies. The main therapeutic strategies are: activation of the ipsilesional motor cortex, inhibition of the contralesional motor cortex and modulation of the sensory afferents. Keeping a cortical representation of the upper limb distal extremity could prevent the learned non-use phenomenon. The modulation of sensory afferents is then proposed: distal cutaneous electrostimulation, anesthesia of the healthy limb, mirror therapy, virtual reality. Intensifying the rehabilitation care means increasing the total hours of rehabilitation dedicated to the paretic limb (proprioceptive stimulation and repetitive movements). This specific rehabilitation is facilitated by robot-aided therapy in the active-assisted mode, neuromuscular electrostimulation and bilateral task training. Intensifying the rehabilitation training program significantly improves the arm function outcome when performed during subacute stroke rehabilitation (< six months). Ipsilesional neurostimulation as well as mental practice optimize the effect of repetitive gestures for slight motor impairments. Contralesional neurostimulation or anesthesia of the healthy hand both improve the paretic hand's dexterity via a decrease of the transcallosal inhibition. This pathophysiological mechanism could also explain the positive impact of constraint-induced movement therapy (CI therapy) in an environmental setting for chronic stroke patients. To ensure a positive functional outcome, stroke rehabilitation programs are based on task-oriented repetitive training. This literature review shows that exercising the hemiparetic hand and wrist is essential in all stages of a stroke rehabilitation program. New data stemming from neurosciences suggest that ipsilesional corticospinal excitability should be a priority.

[Functional cardiovascular assessment in dentists performing local anesthesia in out-patient settings].

PubMed

Rabinovich, S A; Razumova, S N; Vasil'ev, Yu L

The article presents the results of the cardiovascular changes assessment using electrocardiography (ECG) monitoring during local anesthesia in GP dentists. Selective ECG monitoring was carried out in 60 dentists aged 25-55 years (1 group - 25-34 y.o.; 2 group - 35-44 y.o.; 3 group - 45-55 y.o.) by means of portable «Valens» system. The study of stress index or the index of regulatory systems tension (IT) was conducted for 6 hours in the first day half within 1 working day. IT from 50 to 150 relative units was considered normal. In the first group IT peak was observed at the time of expectation of clinically relevant anesthesia in upper and lower jaw, while in the second and third groups it was associated with pain reaction in the course of treatment despite of clinical signs of anesthesia in the maxilla (IT=20±5.3 and 231±1.4, correspondingly) and mandible (IT=213±2.7 and 223±2.6, correspondingly). In all groups greater IT correlated more with mandible anesthesia events.

Restructuring consciousness –the psychedelic state in light of integrated information theory

PubMed Central

Gallimore, Andrew R.

2015-01-01

The psychological state elicited by the classic psychedelics drugs, such as LSD and psilocybin, is one of the most fascinating and yet least understood states of consciousness. However, with the advent of modern functional neuroimaging techniques, the effect of these drugs on neural activity is now being revealed, although many of the varied phenomenological features of the psychedelic state remain challenging to explain. Integrated information theory (IIT) is one of the foremost contemporary theories of consciousness, providing a mathematical formalization of both the quantity and quality of conscious experience. This theory can be applied to all known states of consciousness, including the psychedelic state. Using the results of functional neuroimaging data on the psychedelic state, the effects of psychedelic drugs on both the level and structure of consciousness can be explained in terms of the conceptual framework of IIT. This new IIT-based model of the psychedelic state provides an explanation for many of its phenomenological features, including unconstrained cognition, alterations in the structure and meaning of concepts and a sense of expanded awareness. This model also suggests that whilst cognitive flexibility, creativity, and imagination are enhanced during the psychedelic state, this occurs at the expense of cause-effect information, as well as degrading the brain's ability to organize, categorize, and differentiate the constituents of conscious experience. Furthermore, the model generates specific predictions that can be tested using a combination of functional imaging techniques, as has been applied to the study of levels of consciousness during anesthesia and following brain injury. PMID:26124719

Challenging the Myth of Right Nondominant Hemisphere: Lessons from Corticosubcortical Stimulation Mapping in Awake Surgery and Surgical Implications.

PubMed

Vilasboas, Tatiana; Herbet, Guillaume; Duffau, Hugues

2017-07-01

For many years, the right hemisphere (RH) was considered as nondominant, especially in right-handers. In neurosurgical practice, this dogma resulted in the selection of awake procedure with language mapping only for lesions of the left dominant hemisphere. Conversely, surgery under general anesthesia (possibly with motor mapping) was usually proposed for right lesions. However, when objective neuropsychological assessments were performed, they frequently showed cognitive and behavioral deficits after brain surgery, even in the RH. Therefore, to preserve an optimal quality of life, especially in patients with a long survival expectancy (as in low-grade gliomas), awake surgery with cortical and axonal electrostimulation mapping has recently been proposed for resection of right tumors. Here, we review new insights gained from intraoperative stimulation into the pivotal role of the RH in movement execution and control, visual processes and spatial cognition, language and nonverbal semantic processing, executive functions (e.g., attention), and social cognition (mentalizing and emotion recognition). These original findings, which break with the myth of a nondominant RH, may have important implications in cognitive neurosciences, by improving our knowledge of the functional connectivity of the RH, as well as for the clinical management of patients with a right lesion. In brain surgery, awake mapping should be considered more systematically in the RH. Moreover, neuropsychological examination must be achieved in a more systematic manner before and after surgery within the RH, to optimize care by predicting the likelihood of functional recovery and by elaborating specific programs of rehabilitation. Copyright © 2017 Elsevier Inc. All rights reserved.

Oxidative stress responses of juvenile tambaqui Colossoma macropomum after short-term anesthesia with benzocaine and MS-222.

PubMed

Stringhetta, Giovanna R; Barbas, Luis A L; Maltez, Lucas C; Sampaio, Luís A; Monserrat, José M; Garcia, Luciano O

2017-01-01

The present study aimed to evaluate the effects of benzocaine and tricaine methanesulfonate on oxidative stress parameters of juvenile tambaqui tissues. Fish (n=80) were anesthetized with benzocaine (100 mg L-1) or tricaine (240 mg L-1) and two control groups were used (non-anesthetized fish and fish exposed to ethanol-only). After anesthetic induction 10 fish/anesthetic were euthanized after 3, 12 and 24 hours post-anesthesia and tissue samplings (gills, liver and brain) were performed. Samples were submitted to analyses of enzyme activity glutathione-S-transferase (GST), cellular lipid peroxidation (TBARS) and total antioxidant capacity (ACAP). ACAP increased in gills of benzocaine treatment after 12 hours. The liver showed a reduction in ACAP of tricaine treatment after 12 hours. Both anesthetic treatments showed an increase of ACAP at 24 hours compared to control group. The activity of the GST enzyme increased in the gills for treatments benzocaine and tricaine after 3 and 12 hours. Liver showed increased GST activity (benzocaine after 24 hours and tricaine after 3 and 24 hours). Lipid damage decreased in gills (both anesthetics) and brain (tricaine) after 24 hours. The results demonstrate that benzocaine and tricaine did not cause oxidative damage in juvenile tambaqui under the experimental conditions herein established.

Isoflurane anesthesia results in reversible ultrastructure and occludin tight junction protein expression changes in hippocampal blood-brain barrier in aged rats.

PubMed

Cao, Yiyun; Ni, Cheng; Li, Zhengqian; Li, Lunxu; Liu, Yajie; Wang, Chunyi; Zhong, Yanfeng; Cui, Dehua; Guo, Xiangyang

2015-02-05

The underlying mechanism of isoflurane-induced cognitive dysfunction in older individuals is unknown. In this study, the effects of isoflurane exposure on the hippocampal blood-brain barrier (BBB) in aged rats were investigated because it was previously shown that BBB disruption involves in cognitive dysfunction. Twenty-month-old rats randomly received 1.5% isoflurane or vehicle gas as control. Hippocampal BBB ultrastructure was analyzed by transmission electron microscopy and expression of tight junction proteins was measured by western blot analysis. BBB permeability was detected with sodium fluorescein extravasation and further confirmed by immunoglobulin G immunohistochemistry. Spatial learning and memory were assessed by the Morris water maze test. Isoflurane anesthesia resulted in reversible time-dependent BBB ultrastructure morphological damage and significant decreases in expression of the tight junction proteins occludin, which contributed to sodium fluorescein and IgG leakage. Rats with isoflurane exposure also showed significant cognitive deficits in the Morris water maze test. This in vivo data indicate that occludin down-regulation may be one of the mediators of isoflurane-induced hippocampus BBB disruption, and may contribute to hippocampus-dependent cognitive impairment after isoflurane exposure in aged rats. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Electroencephalogram Signatures of Ketamine-Induced Unconsciousness

PubMed Central

Akeju, Oluwaseun; Song, Andrew H.; Hamilos, Allison E.; Pavone, Kara J.; Flores, Francisco J.; Brown, Emery N.; Purdon, Patrick L.

2016-01-01

Objectives Ketamine is an N-methyl-D-aspartate receptor antagonist commonly administered as a general anesthetic. However, circuit level mechanisms to explain ketamine-induced unconsciousness in humans are yet to be clearly defined. Disruption of frontal-parietal network connectivity has been proposed as a mechanism to explain this brain state. However, this mechanism was recently demonstrated at subanesthetic doses of ketamine in awake-patients. Therefore we investigated whether there is an electroencephalogram (EEG) marker for ketamine-induced unconsciousness. Methods We retrospectively studied the EEG in 12 patients who received ketamine for the induction of general anesthesia. We analyzed the EEG dynamics using power spectral and coherence methods. Results Following the administration of a bolus dose of ketamine to induce unconsciousness, we observed a “gamma burst” EEG pattern that consisted of alternating slow-delta (0.1-4 Hz) and gamma (~27-40 Hz) oscillations. This pattern was also associated with increased theta oscillations (~4-8 Hz) and decreased alpha/beta oscillations (~10-24 Hz). Conclusions Ketamine-induced unconsciousness is associated with a gamma burst EEG pattern. Significance We postulate that the gamma burst pattern is a thalamocortical rhythm based on insights previously obtained from cat neurophysiological experiments. This EEG signature of ketamine-induced unconsciousness may offer new insights into general anesthesia induced brain states. PMID:27178861

Anesthesia equipment malfunction: origins and clinical recognition.

PubMed Central

McIntyre, J. W.

1979-01-01

Equipment malfunction is a problem of particular importance during anesthesia and resuscitation. A review of published reports shows that the most common clinical events involve endotracheal tubes, the inspired oxygen concentration, the volume of inspired anesthetic vapours and gases, and pressures in the breathing or ventilation system. It is concluded that protection of a patient from equipment malfunction depends on: (a) appropriate application of standards set by a national standards association; (b) careful evaluation of equipment prior to purchase; (c) comprehension of equipment function by the user; (d) conscientious routine servicing of all systems concerned with anesthesia and resuscitation, and checking after service and before clinical use; (e) preanesthesia testing of equipment, including the use of an oxygen analyser in the breathing circuit; (f) early inclusion of equipment malfunction in the differential diagnosis of events during anesthesia; and (g) rapid action that cannot present a new hazard to the patient to correct the results of apparatus malfunction. PMID:436069

Awake Craniotomy with Noninvasive Brain Mapping by 3-Tesla Functional Magnetic Resonance Imaging for Excision of Low-grade Glioma: A Case of a Young Patient from Pakistan.

PubMed

Aleem Bhatti, Atta Ul; Jakhrani, Nasir Khan; Parekh, Maria Adnan

2018-01-01

The past few years have seen increasing support for gross total resection in the management of low-grade gliomas (LGGs), with a greater extent of resection correlated with better overall survival, progression-free survival, and time to malignant transformation. There is consistent evidence in literature supporting extent of safe resection as a good prognostic indicator as well as positively affecting seizure control, symptomatic relief in pressure symptoms, and longer progression-free and total survival. The operative goal in most LGG cases is to maximize the extent of resection for these benefits while avoiding postoperative neurologic deficits. Several advanced invasive and noninvasive surgical techniques such as intraoperative magnetic resonance imaging (MRI), fluorescence-guided surgery, intraoperative functional pathway mapping, and neuronavigation have been developed in an attempt to better achieve maximal safe resection. We present a case of LGG in a young patient with a 5-year history of refractory seizures and gradual onset walking difficulty. Serial MRI brain scans revealed a progressive increase in right frontal tumor size with substantial edema and parafalcine herniation. Noninvasive brain mapping by functional MRI (fMRI) and sleep-awake-sleep type of anesthesia with endotracheal tube insertion was utilized during an awake craniotomy. Histopathology confirmed a Grade II oligodendroglioma, and genetic analysis revealed no codeletion at 1p/19q. Neurological improvement was remarkable in terms of immediate motor improvement, and the patient remained completely seizure free on a single antiepileptic drug. There is no radiologic or clinical evidence of recurrence 6 months postoperatively. This is the first published report of an awake craniotomy for LGG in Pakistan. The contemporary concept of supratotal resection in LGGs advocates generous functional resection even beyond MRI findings rather than mere excision of oncological boundaries. This relatively aggressive approach is only possible with an awake craniotomy, which ensures preservation of functional status and thus less postoperative morbidity and better outcomes. Noninvasive mapping for intracranial space-occupying lesions, including fMRI and blood-oxygen-level dependent (BOLD) imaging modality, is an essential tool in a resource-limited setting such as Pakistan.

Selective spinal anesthesia versus intravenous propofol in transrectal ultrasound-guided prostate biopsy.

PubMed

Sundarathiti, Petchara; Sirinan, Chomchaba; Seangrung, Rattaphol; Watcharotayangul, Jittiya; Sithamwilai, Wannipa

2009-07-01

Selective spinal anesthesia (SSA) focuses on the use of minimal doses of intrathecal agents with greater precision and selectivity so that return of function occurs rapidly. The authors compared the efficacy of 1.25 mg of hyperbaric bupivacaine intrathecally with propofol anesthesia in terms of hemodynamic stability, surgical conditions and ability to bypass the post anesthetic care unit (PACU). Seventy male patients, 45-85 years old, ASA physical status I-III, were randomly allocated into two groups. Group 1 (n=35) received intrathecal 1.25 mg hyperbaric bupivacaine plus patients cerebrospinal fluid 0.75 ml. Group 2 (n=35) received propofol 1-1.5 mg/kg IV bolus dose and 6-10 mg/kg/hr infusion to maintain surgical anesthesia. The patients in group 1 had adequate anesthesia and were able to walk and bypass the PACU (100%). The need of supplemental oxygen and airway maneuver; the incidence of hypotension and bradycardia were found only in group 2. The surgical conditions were rated as excellent 100% in group 1 and 57.1% in group 2. SSA is superior to propofol anesthesia in terms of hemodynamic stability, surgical conditions and recovery profiles. Even elderly patients were able to walk out from the operating theatre immediately after the procedure.

"Are We hurting ourselves?" What is the prevalence of back pain in anesthesia providers?

PubMed

Anson, Jonathan A; Mets, Elbert J; Vaida, Sonia J; King, Tonya S; Ochoa, Tim; Gordin, Vitaly

2016-11-01

Back injuries are a highly reported category of occupational injury in the health care setting. The daily clinical activities of an anesthesia provider, including lifting, pushing stretchers, transferring patients, and bending for procedures, are risk factors for developing low back pain. The purpose of this study is to investigate the prevalence of work related low back pain in anesthesia providers. We conducted a cross-sectional survey study of anesthesia providers at an academic institution. The target population included all 141 clinical anesthesia providers employed by the Penn State Milton S. Hershey Medical Center Department of Anesthesia. A survey study was conducted using the Oswestry Disability Index (ODI), a validated scoring system for low back pain. Additional questions related to the daily activities of clinical anesthesia practice were also asked. The survey instrument underwent pretesting and clinical sensibility testing to ensure validity and consistent interpretation. The primary self-reported measures were the prevalence of low back pain in anesthesia providers and an assessment of disability based on the ODI. Secondary functional measures included the impact of low back pain on work flow. Nearly half (46.6%) of respondents suffer from low back pain attributed to clinical practice. In this subset of respondents, 70.1% reported not having back pain prior to their anesthesia training. Of those with low back pain, 44% alter their work flow, and 9.8% reported missing at least one day of work. Six providers (5.3%) required surgical intervention. Using the ODI score interpretation guidelines, 46% of respondents had a "mild disability" and 2% had a "moderate disability." Respondents reporting feeling "burned out" from their job had a significantly higher average ODI score compared to those who did not (6.8 vs 3.3, respectively; P=.01). Nearly half of all anesthesia providers sampled suffer from low back pain subjectively attributed to their clinical practice. This leads to changes in work flow and missed days of work. The results of this study suggest a deficiency in the effectiveness of anesthesia training programs in teaching proper techniques to prevent musculoskeletal injuries. Copyright © 2016 Elsevier Inc. All rights reserved.

Improving Patient Safety with X-Ray and Anesthesia Machine Ventilator Synchronization: A Medical Device Interoperability Case Study

NASA Astrophysics Data System (ADS)

Arney, David; Goldman, Julian M.; Whitehead, Susan F.; Lee, Insup

When a x-ray image is needed during surgery, clinicians may stop the anesthesia machine ventilator while the exposure is made. If the ventilator is not restarted promptly, the patient may experience severe complications. This paper explores the interconnection of a ventilator and simulated x-ray into a prototype plug-and-play medical device system. This work assists ongoing interoperability framework development standards efforts to develop functional and non-functional requirements and illustrates the potential patient safety benefits of interoperable medical device systems by implementing a solution to a clinical use case requiring interoperability.

Environmental Enrichment Mitigates Deficits after Repetitive Mild Traumatic Brain Injury.

PubMed

Liu, Xixia; Qiu, Jianhua; Alcon, Sasha; Hashim, Jumana; Meehan, William P; Mannix, Rebekah

2017-08-15

Although environmental enrichment has been shown to improve functional and histologic outcomes in pre-clinical moderate-to-severe traumatic brain injury (TBI), there are a paucity of pre-clinical data regarding enrichment strategies in the setting of repetitive mild traumatic brain injury (rmTBI). Given the vast numbers of athletes and those in the military who sustain rmTBI, the mounting evidence of the long-term and progressive sequelae of rmTBI, and the lack of targeted therapies to mitigate these sequelae, successful enrichment interventions in rmTBI could have large public health significance. Here, we evaluated enrichment strategies in an established pre-clinical rmTBI model. Seventy-one male C57BL/6 mice were randomized to two different housing conditions, environmental enrichment (EE) or normal condition (NC), then subjected to rmTBI injury (seven injuries in 9 days) or sham injury (anesthesia only). Functional outcomes in all four groups (NC-TBI, EE-TBI, NC-sham, and EE-sham) were assessed by motor, exploratory/anxiety, and mnemonic behavioral tests. At the synaptic level, N-methyl d-aspartate receptor (NMDAR) subunit expression of phosphorylated glutamate receptor 1 (GluR1), phosphorylated Ca 2+ /calmodulin-dependent protein kinase II (CaMKII), and calpain were evaluated by western blot. Compared to injured NC-TBI mice, EE-TBI mice had improved memory and decreased anxiety and exploratory activity post-injury. Treatment with enrichment also corresponded to normal NMDAR subunit expression, decreased GluR1 phosphorylation, decreased phosphorylated CaMKII, and normal calpain expression post-rmTBI. These data suggest that enrichment strategies may improve functional outcomes and mitigate synaptic changes post-rmTBI. Given that enrichment strategies are feasible in the clinical setting, particularly for athletes and soldiers for whom the risk of repetitive injury is greatest, these data suggest that clinical trials may be warranted.

Hydrogen gas attenuates sevoflurane neurotoxicity through inhibiting nuclear factor κ-light-chain-enhancer of activated B cells signaling and proinflammatory cytokine release in neonatal rats.

PubMed

Shi, Yiwei; Wang, Gang; Li, Jinyuan; Yu, Wenli

2017-12-06

Anesthesia neurotoxicity in developing brain has gained increasing attention. However, knowledge regarding its mitigating strategies remains scant. Sevoflurane, a commonly used anesthetic, is responsible for learning and memory deficits in neonates. Molecular hydrogen is reported to be a potential neuroprotective agent because of its antioxidative and anti-inflammatory activities. This study aimed to investigate the effect of hydrogen gas on sevoflurane neurotoxicity. The newborn rats were treated with sevoflurane and/or hydrogen gas for 2 h. Spatial recognition memory and fear memory were determined by Y-maze and fear conditioning tests at 10 weeks of age. Nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and proinflammatory cytokine levels were detected using western blot analysis. The data showed that the spatial recognition memory and fear memory of the rats treated with sevoflurane decreased compared with the control, and the cognitive function of the rats treated with sevoflurane and hydrogen gas significantly increased in comparison with treatment with sevoflurane alone. Moreover, hydrogen gas suppressed NF-κB phosphorylation and nuclear translocation and reduced the production of interleukin-1β, interleukin-6, and tumor necrosis factor-α following sevoflurane administration. Thus, the results proposed that hydrogen gas might protect against sevoflurane neurotoxicity by inhibiting NF-κB activation and proinflammatory cytokine release, providing a novel therapeutic strategy for anesthesia neurotoxicity.

[A case of severe asthma exacerbation complicated with cerebral edema and diffuse multiple cerebral micro-bleeds].

PubMed

Ohkura, Noriyuki; Fujimura, Masaki; Sakai, Asao; Fujita, Kentaro; Katayama, Nobuyuki

2009-08-01

A 36-year-old woman was admitted to the Intensive Care Unit for the treatment of severe asthma exacerbation. Her condition of asthma improved with systemic glucocorticosteroids, inhaled beta2-agonist, intravenous theophylline and inhaled anesthesia (isoflurane) under mechanical ventilation. Her consciousness was disturbed even after terminating isoflurane. Brain CT and MRI scan showed cerebral edema and diffuse multiple cerebral micro-bleeds. Glyceol, a hyperosmotic diuretic solution consisting of 10% glycerol and 5% fructose in saline, was administered to decrease cerebral edema. Her consciousness disturbance gradually recovered. Cerebral edema and hemorrhage improved. On the 69th hospital day, she was discharged from hospital without sequelae. This case is a rare one in which severe asthma exacerbation was complicated with cerebral edema and diffuse multiple cerebral hemorrhage. Inhaled anesthesia for asthma exacerbation should be used carefully to avoid delay of diagnosis of central nervous system complications.

Biothermal Model of Patient and Automatic Control System of Brain Temperature for Brain Hypothermia Treatment

NASA Astrophysics Data System (ADS)

Wakamatsu, Hidetoshi; Gaohua, Lu

Various surface-cooling apparatus such as the cooling cap, muffler and blankets have been commonly used for the cooling of the brain to provide hypothermic neuro-protection for patients of hypoxic-ischemic encephalopathy. The present paper is aimed at the brain temperature regulation from the viewpoint of automatic system control, in order to help clinicians decide an optimal temperature of the cooling fluid provided for these three types of apparatus. At first, a biothermal model characterized by dynamic ambient temperatures is constructed for adult patient, especially on account of the clinical practice of hypothermia and anesthesia in the brain hypothermia treatment. Secondly, the model is represented by the state equation as a lumped parameter linear dynamic system. The biothermal model is justified from their various responses corresponding to clinical phenomena and treatment. Finally, the optimal regulator is tentatively designed to give clinicians some suggestions on the optimal temperature regulation of the patient’s brain. It suggests the patient’s brain temperature could be optimally controlled to follow-up the temperature process prescribed by the clinicians. This study benefits us a great clinical possibility for the automatic hypothermia treatment.

Feasibility and Pilot Study of the Pediatric Anesthesia NeuroDevelopment Assessment (PANDA) Project

PubMed Central

Sun, Lena S.; Li, Guohua; DiMaggio, Charles J.; Byrne, Mary W.; Ing, Caleb; Miller, Tonya LK; Bellinger, David C.; Han, Sena; McGowan, Francis X.

2012-01-01

Background Animal studies have documented that exposure of the developing brain to commonly used anesthetic agents induce neurotoxicity and late abnormal neurobehavioral functions as adults. Results from clinical studies have all been performed using existing datasets, and produced inconsistent results. To provide more definitive evidence to address the clinical relevance of anesthetic neurotoxicity in children, an interdisciplinary team of investigators designed and developed the Pediatric Anesthesia NeuroDevelopment Assessment (PANDA) project. We present pilot study results in 28 sibling pairs recruited and tested at Columbia University Medical Center (CUMC) and Children’s Hospital of Boston (CHB) for the PANDA project. Methods The PANDA project uses an ambi-directional cohort design. We performed prospective neuropsychological assessment in 28 exposed-unexposed sibling pairs ages 6–11 years old. The exposed siblings were ASA 1 or 2 and had received a single episode of anesthesia for inguinal hernia repair prior to age 36 months and the unexposed siblings had no anesthesia before age 36 months. All sibling pairs were English speaking and were 36 weeks gestational age or greater. Each sibling pair underwent direct testing using WASI and NEPSY II, and the parents completed questionnaires related to behavior using CBCL and Conners’ rating. Data are presented as means ± SD. We conducted descriptive analyses of demographic data. We compared exposed and unexposed sibling groups on WASI and NEPSY II, and total and T-scores from CBCL and Conners’ as continuous data by paired t test between. A P< 0.05 was considered significant. Results Following IRB approval for the study at both CUMC and CHB, the full PANDA study protocol was implemented to perform a pilot feasibility study. Our success rate was 96.7% in obtaining detailed medical and anesthesia records in our historical cohort. Scores for verbal IQ (Exposed=106.1±16.3,Unexposed=109.2±17.9), performance IQ (Exposed=109.1±16.0, Unexposed=113.9±15.9) and full IQ (Exposed=108.2±14.0, Unexposed=112.8±16.8) were comparable between siblings. There were no differences between the two groups in T scores for any of the NEPSY II sub-domains, CBCL or Conners’. An abstraction protocol with web-based electronic data capture forms also was developed in conjunction with the International Center for Health Outcomes and Innovation Research (InCHOIR). Conclusions The pilot study provided useful information for feasibility to recruit the sample size and to obtain relevant clinical data. For the final study protocol, both the neuropsychological battery and the age range for testing were revised. Our results confirmed the feasibility of our study approach, and yielded pilot data from neuropsychological testing. PMID:23076226

Local anesthesia selection algorithm in patients with concomitant somatic diseases.

PubMed

Anisimova, E N; Sokhov, S T; Letunova, N Y; Orekhova, I V; Gromovik, M V; Erilin, E A; Ryazantsev, N A

2016-01-01

The paper presents basic principles of local anesthesia selection in patients with concomitant somatic diseases. These principles are history taking; analysis of drugs interaction with local anesthetic and sedation agents; determination of the functional status of the patient; patient anxiety correction; dental care with monitoring of hemodynamics parameters. It was found that adhering to this algorithm promotes prevention of urgent conditions in patients in outpatient dentistry.

[Anesthesia in bronchial asthma].

PubMed

Bremerich, D H

2000-09-01

Asthma is defined as a chronic inflammatory airway disease in response to a wide variety of provoking stimuli. Characteristic clinical symptoms of asthma are bronchial hyperreactivity, reversible airway obstruction, wheezing and dyspnea. Asthma presents a major public health problem with increasing prevalence rates and severity worldwide. Despite major advances in our understanding of the clinical management of asthmatic patients, it remains a challenging population for anesthesiologists in clinical practice. The anesthesiologist's responsibility starts with the preoperative assessment and evaluation of the pulmonary function. For patients with asthma who currently have no symptoms, the risk of perioperative respiratory complications is extremely low. Therefore, pulmonary function should be optimized preoperatively and airway obstruction should be controlled by using steroids and bronchodilators. Preoperative spirometry is a simple means of assessing presence and severity of airway obstruction as well as the degree of reversibility in response to bronchodilator therapy. An increase of 15% in FEV1 is considered clinically significant. Most asymptomatic persons with asthma can safely undergo general anesthesia with and without endotracheal intubation. Volatile anesthetics are still recommended for general anesthetic techniques. As compared to barbiturates and even ketamine, propofol is considered to be the agent of choice for induction of anesthesia in asthmatics. The use of regional anesthesia does not reduce perioperative respiratory complications in asymptomatic asthmatics, whereas it is advantageous in symptomatic patients. Pregnant asthmatic and parturients undergoing anesthesia are at increased risk, especially if regional anesthetic techniques are not suitable and prostaglandin and its derivates are administered for abortion or operative delivery. Bronchial hyperreactivity associated with asthma is an important risk factor of perioperative bronchospasm. The occurrence of this potentially life-threatening condition in anesthesia practice varies from 0.17 to 4.2%. The anesthesiologists' goal should be to minimize the risk of inciting bronchospasm and to avoid triggering stimuli. As increases in airway resistance are noticed, therapy should be directed towards optimizing oxygenation and proper diagnosis needs to be established. With deepening anesthesia level and aggressive pharmacological management utilizing both, beta-agonists and steroids, respiratory failure may be properly controlled.

Rofecoxib does not compromise platelet aggregation during anesthesia and surgery.

PubMed

Silverman, David G; Halaszynski, Thomas; Sinatra, Raymond; Luther, Martha; Rinder, Christine S

2003-12-01

This study was undertaken because, although there is evidence that cyclooxygenase type 2 (COX)-2 inhibitors do not compromise platelets in healthy volunteers, many clinicians remain hesitant to administer them perioperatively without definitive evidence of intact platelet function during anesthesia and surgery. In 20 patients scheduled for lower abdominal and pelvic surgery, 5 mL of blood were obtained for baseline platelet aggregometry. One hour prior to surgery, patients received an oral solution of either rofecoxib (ROF) 50 mg or placebo (PLAC) by randomized, double-blinded assignment. Approximately one hour after onset of anesthesia, an intraoperative blood sample was obtained. Baseline and postdrug samples were centrifuged to generate platelet-rich plasma, which was challenged with adenosine diphosphate (ADP) and arachidonic acid (AA). Aggregometry was performed with and without incubation with aspirin. The data in each subject were normalized to baseline aggregation in response to AA alone and ADP alone. Intergroup differences were assessed using paired t test; P < 0.05 was considered significant. Consistent with known effects of anesthesia on platelet function, both groups had approximately 25% intraoperative declines in aggregation in response to ADP (P = NS for PLAC vs ROF) and even greater declines in response to AA (P = NS for PLAC vs ROF). Aspirin eliminated aggregation in response to AA in both groups (P = NS), and it caused similar declines in PLAC and ROF groups during exposure to ADP (P = NS). This study provides strong evidence that ROF does not compromise platelet aggregation during anesthesia and surgery; nor does it interfere with the platelet inhibitory effect of aspirin.

Anesthetic biotransformation and renal function in obese patients during and after methoxyflurane or halothane anesthesia.

PubMed

Young, S R; Stoelting, R K; Peterson, C; Madura, J A

1975-04-01

Anesthetic biotransformation and renal function were studied in obese adult patients (148 plus or minus 8 kg; mean plus or minus SE) anesthetized for three hours with 60 per cent nitrous oxide plus either methoxyflurane or halothane for elective jejunoileal small-bowel-bypass operations. There was no evidence of persistent renal dysfunction in any patient postoperatively, but serum osmolality was elevated 72 hours after methoxyflurane anesthesia. Urine concentrating ability was not determined. Peak serum ionic fluoride concentration was 55.8 plus or minus 5.8 muM/1 two hours after discontinuation of methoxyflurane. Urinary ionic fluoride and oxalate excretions increased postoperatively. Compared with previously reported data from nonobese patients, serum ionic fluoride concentrations in obese patients increased more rapidly during methoxyflurane anesthesia and peaked higher and sooner after discontinuation of methoxyflurane. The peak serum ionic fluoride concentration was 10.4 plus or minus 1.5 muM/1 at the conclusion of halothane anesthesia, significantly more than the corresponding value in nonobese patients. Intraoperative liver biopsies from 23 of 27 patients showed moderate to severe fatty metamorphosis. Fatty liver infiltration may have increased hepatic anesthetic uptake and exposed more methoxyflurane or halothane to hepatic microsomal enzymes. The more rapid elevation and higher peak levels of serum ionic fluoride following methoxyflurane, and to a lesser extent following halothane, may reflect increased anesthetic biotransformation in obese compared with nonobese patients. To avoid excessive serum ionic fluoride elevations the authors recommended limiting low-dose methoxyflurane anesthesia delivered to obese patients with potential fatty liver infiltration to no more than three hours.

The effects of anesthetic agents on pupillary function during general anesthesia using the automated infrared quantitative pupillometer.

PubMed

Shirozu, Kazuhiro; Setoguchi, Hidekazu; Tokuda, Kentaro; Karashima, Yuji; Ikeda, Mizuko; Kubo, Makoto; Nakamura, Katsuya; Hoka, Sumio

2017-04-01

Pupil reactivity can be used to evaluate central nervous system function and can be measured using a quantitative pupillometer. However, whether anesthetic agents affect the accuracy of the technique remains unclear. We examined the effects of anesthetic agents on pupillary reactivity. Thirty-five patients scheduled for breast or thyroid surgery were enrolled in the study. Patients were divided into four groups based on the technique used to maintain anesthesia: a sevoflurane-remifentanil (SEV/REM) group, a sevoflurane (SEV) group, a desflurane-remifentanil (DES/REM) group, and a propofol-remifentanil (PRO/REM) group. We measured maximum resting pupil size (MAX), reduction pupil size ratio (%CH), latency duration (LAT) and neurological pupil index (NPi). A marked reduction in MAX and %CH compared with baseline was observed in all groups, but LAT was unchanged during surgery. NPi reduced within the first hour of surgery in the SEV/REM, SEV, and DES/REM groups, but was not significantly different in the PRO/REM group. Compared with the PRO/REM group, mean %CH and NPi in patients anesthetized with SEV/REM, SEV or DES/REM were markedly lower at 1 h after surgery had commenced. There was no correlation between NPi and bispectral index. Fentanyl given alone decreased pupil size and %CH in light reflex, but did not change the NPi. NPi was decreased by inhalational anesthesia not but intravenous anesthesia. The difference in pupil reactivity between inhalational anesthetic and propofol may indicate differences in the alteration of midbrain reflexs in patients under inhalational or intravenous anesthesia.

The effects of memantine on recovery, cognitive functions, and pain after propofol anesthesia.

PubMed

Emik, Ulku; Unal, Yusuf; Arslan, Mustafa; Demirel, Cengiz Bekir

2016-01-01

Postoperative cognitive dysfunction refers to the problems associated with thought and memory that are often experienced after major surgery. The aim of this study is to evaluate the effects of intraperitoneally administered memantine on recovery, cognitive functions, and pain after propofol anesthesia. The study was conducted in Gazi University Animal Research Laboratory, Ankara, Turkey in January 2012. Twenty-four adult female Wistar Albino rats weighing 170-270g were educated for 300s in the radial arm maze (RAM) over three days. Group P was administered 150mgkg(-1) of intraperitoneal (IP) propofol; Group M was given 1mgkg(-1) of IP memantine; and Group MP was given 1mgkg(-1) of IP memantine before being administered 150mgkg(-1) of IP propofol. The control group received only IP saline. RAM and hot plate values were obtained after recovery from the groups that received propofol anesthesia and 30min after the administration of drugs in other two groups. The duration of recovery for Group MP was significantly shorter than Group P (p<0.001), and the number of entries and exits in the RAM by Group MP was significantly higher during the first hour when compared to Group P (p<0.0001). Hot plate values, on the other hand, were found to be significantly increased in all groups when compared to the control values, aside from Group C (p<0.0001). In this study, memantine provided shorter recovery times, better cognitive functions, and reduced postoperative pain. From this study, we find that memantine has beneficial effects on recovery, cognitive functions, and pain after propofol anesthesia. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Intraoperative Neurophysiological Monitoring : A Review of Techniques Used for Brain Tumor Surgery in Children.

PubMed

Kim, Keewon; Cho, Charles; Bang, Moon-Suk; Shin, Hyung-Ik; Phi, Ji-Hoon; Kim, Seung-Ki

2018-05-01

Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal ageadjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.

Cerebral hemodynamic changes and electroencephalography during carotid endarterectomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Algotsson, L.; Messeter, K.; Rehncrona, S.

Some patients undergoing endarterectomy for occlusive carotid artery disease run a risk of brain ischemia during cross-clamping of the artery. The present study of 15 patients was undertaken to evaluate changes in cerebral blood flow (CBF), as measured with an intravenous (IV) tracer (133Xenon) technique, and to relate CBF changes to changes in the electroencephalogram (EEG). CBF was measured before and after induction of anesthesia, during cross-clamping of the carotid artery, after release of the clamps, and at 24 hours after the operation. All the patients were anesthetized with methohexitone, fentanyl, and nitrous oxide and oxygen. EEG was continuously recordedmore » during the operation. Carotid artery shunts were not used. In 8 patients, cross-clamping of the carotid artery did not influence the EEG. In this group of patients, induction of anesthesia caused a 38% decrease in CBF, which presumably reflects the normal reaction to the anesthetic agent given. There were no further changes in CBF during cross-clamping. In 7 patients, the EEG showed signs of deterioration during the intraoperative vascular occlusion. In these patients, anesthesia did not cause any CBF change, whereas cross-clamping the artery induced a 33% decrease in CBF. In individual patients, the severity of EEG changes correlated with the decrease in CBF. The absence of a change in CBF by anesthesia and a decrease due to cross-clamping of the carotid artery may be explained by the presence of a more advanced cerebrovascular disease and an insufficiency to maintain CBF during cross-clamping.« less

The effects of delivery route and anesthesia type on early postnatal weight loss in newborns: the role of vasoactive hormones.

PubMed

Okumus, Nurullah; Atalay, Yildiz; Onal, Eray E; Turkyilmaz, Canan; Senel, Saliha; Gunaydin, Berrin; Pasaoglu, Hatice; Koc, Esin; Ergenekon, Ebru; Unal, Suna

2011-01-01

To investigate the effects of delivery route and maternal anesthesia type and the roles of vasoactive hormones on early postnatal weight loss in term newborns. Ninety-four term infants delivered vaginally (group 1, n=31), cesarean section (C/S) with general anesthesia (GA) (group 2, n=29), and C/S with epidural anesthesia (EA) (group 3, n=34) were included in this study. All infants were weighed at birth and on the second day of life and intravenous (IV) fluid infused to the mothers for the last 6 h prior to delivery was recorded. Serum electrolytes, osmolality, N-terminal proANP (NT-proANP), brain natriuretic peptide (BNP), aldosterone and plasma antidiuretic hormone (ADH) concentrations were measured at cord blood and on the second day of life. Our research showed that postnatal weight loss of infants was higher in C/S than vaginal deliveries (5.7% vs. 1.3%) (p < 0.0001) and in EA group than GA group (6.8% vs. 4.3%) (p < 0.0001). Postnatal weight losses were correlated with IV fluid volume infused to the mothers for the last 6 h prior to delivery (R = 0.814, p = 0.000) and with serum NT-proANP (R = 0.418, p = 0.000), BNP (R = 0.454, p = 0.000), and ADH (R = 0.509, p = 0.000) but not with aldosterone concentrations (p > 0.05). Large amounts of IV fluid given to the mothers who were applied EA prior to the delivery affect their offsprings' postnatal weight loss via certain vasoactive hormones.

[A case of postoperative airway obstruction by Quincke edema].

PubMed

Ebata, S; Fujii, Y; Kojima, Y; Tanaka, H

1994-05-01

A 42-year-old female was scheduled for removal of brain tumor under general anesthesia with nitrous oxide, oxygen and isoflurane. Two days after operation, airway obstruction by increased swelling around the neck was observed. The first neck X-ray films and CT-scans after operation were not indicative of the hematoma or cyst but suggestive of the neurovascular edema (Quincke). It is necessary not to overlook postoperative airway obstruction by Quincke's edema.

Characterization of Sleep Using Bispectral Analysis

DTIC Science & Technology

2001-10-25

approved the Bispectral Index (BIS) - developed by Aspect Medical Systems (Natick, MA) - as a tool for monitoring the depth of anesthesia based on...on the brain [2]. The A-1000 BIS monitor quantifies the level of hypnosis based on frequency, amplitude, and coherence of the EEG. The BIS index...on a scale of 0-100 (100 reflecting the fully conscious or awake state), is a single-number indicator of the level of induced hypnosis . Furthermore

The effect of timing of manipulation under anesthesia to improve range of motion and functional outcomes following total knee arthroplasty.

PubMed

Issa, Kimona; Banerjee, Samik; Kester, Mark A; Khanuja, Harpal S; Delanois, Ronald E; Mont, Michael A

2014-08-20

Manipulation under anesthesia has been reported to improve range of motion when other rehabilitative efforts fail to obtain adequate motion after total knee arthroplasty. The purpose of this study was to evaluate the effects of the timing of the manipulation on knee range of motion and clinical outcomes. All 2128 total knee arthroplasties performed at our institution from 2005 to 2011 were reviewed to determine the number of patients who had undergone manipulation under anesthesia. A total of 144 manipulations in eighty-eight women and forty-five men were reviewed. Manipulations under anesthesia that were performed within the first twelve weeks after total knee arthroplasty were considered early and those after that period were considered late. Patients were further substratified according to the timing of the manipulation: Group I included those who had the manipulation within six weeks; Group II, at seven to twelve weeks; Group III, at thirteen to twenty-six weeks; and Group IV, after twenty-six weeks. Outcomes evaluated included gains in flexion and final range of motion, and Knee Society objective and function scores between early and late manipulation, using various adjusted multivariable regression models and at a mean follow-up of fifty-one months (range, twelve to eighty-one months). Mediation analysis was used to investigate whether gains in range of motion from the manipulations under anesthesia alone had mediated the effect between the timing of the manipulation and the clinical outcomes. Patients who underwent early manipulation had a significantly higher mean gain in flexion (36.5° versus 17°), higher final range of motion (119° versus 95°), and higher Knee Society objective (89 versus 84 points) and function scores (88 versus 83 points) than those who had late manipulation under anesthesia. There were no significant differences in the outcomes of Groups I and II. Manipulations after twenty-six weeks resulted in unsatisfactory clinical outcomes. Multivariable regression analyses confirmed significantly better clinical outcomes with early manipulation. Mediation analysis showed that the timing of manipulation independently had significantly contributed to the outcomes. Orthopaedic surgeons should have a low threshold for performing early manipulations with the patient under anesthesia within twelve weeks after an arthroplasty, to achieve higher knee range of motion and improved clinical outcomes. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Monitoring of cerebral blood flow autoregulation in adults undergoing sevoflurane anesthesia: a prospective cohort study of two age groups.

PubMed

Goettel, Nicolai; Patet, Camille; Rossi, Ariane; Burkhart, Christoph S; Czosnyka, Marek; Strebel, Stephan P; Steiner, Luzius A

2016-06-01

Autoregulation of blood flow is a key feature of the human cerebral vascular system to assure adequate oxygenation and metabolism of the brain under changing physiological conditions. The impact of advanced age and anesthesia on cerebral autoregulation remains unclear. The primary objective of this study was to determine the effect of sevoflurane anesthesia on cerebral autoregulation in two different age groups. This is a follow-up analysis of data acquired in a prospective observational cohort study. One hundred thirty-three patients aged 18-40 and ≥65 years scheduled for major noncardiac surgery under general anesthesia were included. Cerebral autoregulation indices, limits, and ranges were compared in young and elderly patient groups. Forty-nine patients (37 %) aged 18-40 years and 84 patients (63 %) aged ≥65 years were included in the study. Age-adjusted minimum alveolar concentrations of sevoflurane were 0.89 ± 0.07 in young and 0.99 ± 0.14 in older subjects (P < 0.001). Effective autoregulation was found in a blood pressure range of 13.8 ± 9.8 mmHg in young and 10.2 ± 8.6 mmHg in older patients (P = 0.079). The lower limit of autoregulation was 66 ± 12 mmHg and 73 ± 14 mmHg in young and older patients, respectively (P = 0.075). The association between sevoflurane concentrations and autoregulatory capacity was similar in both age groups. Our data suggests that the autoregulatory plateau is shortened in both young and older patients under sevoflurane anesthesia with approximately 1 MAC. Lower and upper limits of cerebral blood flow autoregulation, as well as the autoregulatory range, are not influenced by the age of anesthetized patients. Trial registration ClinicalTrials.gov (NCT00512200).

Frontal-temporal synchronization of EEG signals quantified by order patterns cross recurrence analysis during propofol anesthesia.

PubMed

Shalbaf, Reza; Behnam, Hamid; Sleigh, Jamie W; Steyn-Ross, D Alistair; Steyn-Ross, Moira L

2015-05-01

Characterizing brain dynamics during anesthesia is a main current challenge in anesthesia study. Several single channel electroencephalogram (EEG)-based commercial monitors like the Bispectral index (BIS) have suggested to examine EEG signal. But, the BIS index has obtained numerous critiques. In this study, we evaluate the concentration-dependent effect of the propofol on long-range frontal-temporal synchronization of EEG signals collected from eight subjects during a controlled induction and recovery design. We used order patterns cross recurrence plot and provide an index named order pattern laminarity (OPL) to assess changes in neuronal synchronization as the mechanism forming the foundation of conscious perception. The prediction probability of 0.9 and 0.84 for OPL and BIS specified that the OPL index correlated more strongly with effect-site propofol concentration. Also, our new index makes faster reaction to transients in EEG recordings based on pharmacokinetic and pharmacodynamic model parameters and demonstrates less variability at the point of loss of consciousness (standard deviation of 0.04 for OPL compared with 0.09 for BIS index). The result show that the OPL index can estimate anesthetic state of patient more efficiently than the BIS index in lightly sedated state with more tolerant of artifacts.

Intraoperative seizures during craniotomy under general anesthesia.

PubMed

Howe, John; Lu, Xiaoying; Thompson, Zoe; Peterson, Gordon W; Losey, Travis E

2016-05-01

An acute symptomatic seizure is a clinical seizure occurring at the time of or in close temporal association with a brain insult. We report an acute symptomatic seizure occurring during a surgical procedure in a patient who did not have a prior history of epilepsy and who did not have a lesion associated with an increased risk of epilepsy. To characterize the incidence and clinical features of intraoperative seizures during craniotomy under general anesthesia, we reviewed cases where continuous EEG was acquired during craniotomy. Records of 400 consecutive cases with propofol as general anesthesia during craniotomy were reviewed. Demographic data, indication for surgery, clinical history, history of prior seizures, duration of surgery and duration of burst suppression were recorded. Cases where seizures were observed were analyzed in detail. Two out of 400 patients experienced intraoperative seizures, including one patient who appeared to have an acute symptomatic seizure related to the surgical procedure itself and a second patient who experienced two seizures likely related to an underlying diagnosis of epilepsy. This is the first report of an acute symptomatic seizure secondary to a neurosurgical procedure. Overall, 0.5% of patients monitored experienced seizures, indicating that intraoperative seizures are rare, and EEG monitoring during craniotomies is of low yield in detecting seizures. Copyright © 2016. Published by Elsevier Ltd.

An Observational Assessment of Anesthesia Capacity in Madagascar as a Prerequisite to the Development of a National Surgical Plan.

PubMed

Baxter, Linden S; Ravelojaona, Vaonandianina A; Rakotoarison, Hasiniaina N; Herbert, Alison; Bruno, Emily; Close, Kristin L; Andean, Vanessa; Andriamanjato, Hery H; Shrime, Mark G; White, Michelle C

2017-06-01

The global lack of anesthesia capacity is well described, but country-specific data are needed to provide country-specific solutions. We aimed to assess anesthesia capacity in Madagascar as part of the development of a Ministry of Health national surgical plan. As part of a nationwide surgical safety quality improvement project, we surveyed 19 of 22 regional hospitals, representing surgical facilities caring for 75% of the total population. The assessment was divided into 3 areas: anesthesia workforce density, infrastructure and equipment, and medications. Data were obtained by semistructured interviews with Ministry of Health officials, hospital directors, technical directors, statisticians, pharmacists, and anesthesia providers and through on-site observations. Interview questions were adapted from the World Health Organization Situational Analysis Tool and the World Federation of Societies of Anaesthesiologists International Standards for Safe Practice of Anaesthesia. Additional data on workforce density were collected from the 3 remaining regions so that workforce density data are representative of all 22 regions. Anesthesia physician workforce density is 0.26 per 100,000 population and 0.19 per 100,000 outside of the capital region. Less than 50% of hospitals surveyed reported having a reliable electricity and oxygen supply. The majority of anesthesia providers work without pulse oximetry (52%) or a functioning vaporizer (52%). All the hospitals surveyed had very basic pediatric supplies, and none had a pediatric pulse oximetry probe. Ketamine is universally available but more than 50% of hospitals lack access to opioids. None of the 19 regional hospitals surveyed was able to completely meet the World Federation of Societies of Anaesthesiologists' standards for monitoring. Improving anesthesia care is complex. Capacity assessment is a first step that would enable progress to be tracked against specific targets. In Madagascar, scale-up of the anesthesia workforce, investment in infrastructure and equipment, and improvement in medication supply-chain management are needed to attain minimal international standards. Data from this study were presented to the Ministry of Health for inclusion in the development of a national surgical plan, together with recommendations for the needed improvements in the delivery of anesthesia.

Anesthesia for a Rare Case of Uncorrected Pentalogy of Fallot Undergoing Craniotomy and Drainage of Brain Abscess.

PubMed

Marulasiddappa, Vinay; Raghavavendra, B S

2015-07-01

Children with uncorrected cyanotic congenital heart diseases can present for non cardiac surgeries. They pose several challenges to the Anaesthesiologist, especially when they are posted for emergency surgery, due to the complex haemodynamic changes secondary to the heart disease. Pentalogy of Fallot (POF) is a rare form of congenital heart disease characterized by the association of Tetralogy of Fallot (TOF) with an atrial septal defect (ASD). TOF is the leading cause of intracardiac right to left shunt and is the commonest type of cyanotic congenital heart disease to cause a brain abscess. Children with POF presenting with brain abscess pose several challenges to the anaesthesiologist due to the altered haemodynamics and warrant a meticulous anaesthetic plan. There are very few case reports of Anaesthesia management of a child with Pentalogy of Fallot (POF) presenting for non cardiac surgery. We report the anaesthetic management of a rare case of a 5-year-old child with uncorrected POF, who presented to our Superspeciality hospital with a brain abscess and underwent an emergency craniotomy with drainage of the brain abscess successfully.

A new microcontroller-based human brain hypothermia system.

PubMed

Kapidere, Metin; Ahiska, Raşit; Güler, Inan

2005-10-01

Many studies show that artificial hypothermia of brain in conditions of anesthesia with the rectal temperature lowered down to 33 degrees C produces pronounced prophylactic effect protecting the brain from anoxia. Out of the methods employed now in clinical practice for reducing the oxygen consumption by the cerebral tissue, the most efficacious is craniocerebral hypothermia (CCH). It is finding even more extensive application in cardiovascular surgery, neurosurgery, neurorenimatology and many other fields of medical practice. In this study, a microcontroller-based designed human brain hypothermia system (HBHS) is designed and constructed. The system is intended for cooling and heating the brain. HBHS consists of a thermoelectric hypothermic helmet, a control and a power unit. Helmet temperature is controlled by 8-bit PIC16F877 microcontroller which is programmed using MPLAB editor. Temperature is converted to 10-bit digital and is controlled automatically by the preset values which have been already entered in the microcontroller. Calibration is controlled and the working range is tested. Temperature of helmet is controlled between -5 and +46 degrees C by microcontroller, with the accuracy of +/-0.5 degrees C.

Variable versus conventional lung protective mechanical ventilation during open abdominal surgery: study protocol for a randomized controlled trial.

PubMed

Spieth, Peter M; Güldner, Andreas; Uhlig, Christopher; Bluth, Thomas; Kiss, Thomas; Schultz, Marcus J; Pelosi, Paolo; Koch, Thea; Gama de Abreu, Marcelo

2014-05-02

General anesthesia usually requires mechanical ventilation, which is traditionally accomplished with constant tidal volumes in volume- or pressure-controlled modes. Experimental studies suggest that the use of variable tidal volumes (variable ventilation) recruits lung tissue, improves pulmonary function and reduces systemic inflammatory response. However, it is currently not known whether patients undergoing open abdominal surgery might benefit from intraoperative variable ventilation. The PROtective VARiable ventilation trial ('PROVAR') is a single center, randomized controlled trial enrolling 50 patients who are planning for open abdominal surgery expected to last longer than 3 hours. PROVAR compares conventional (non-variable) lung protective ventilation (CV) with variable lung protective ventilation (VV) regarding pulmonary function and inflammatory response. The primary endpoint of the study is the forced vital capacity on the first postoperative day. Secondary endpoints include further lung function tests, plasma cytokine levels, spatial distribution of ventilation assessed by means of electrical impedance tomography and postoperative pulmonary complications. We hypothesize that VV improves lung function and reduces systemic inflammatory response compared to CV in patients receiving mechanical ventilation during general anesthesia for open abdominal surgery longer than 3 hours. PROVAR is the first randomized controlled trial aiming at intra- and postoperative effects of VV on lung function. This study may help to define the role of VV during general anesthesia requiring mechanical ventilation. Clinicaltrials.gov NCT01683578 (registered on September 3 3012).

Umbilical hernia in cirrhotic patients: outcome of elective repair.

PubMed

Lasheen, Adel; Naser, Hatem M; Abohassan, Ahmed

2013-12-01

Cirrhotic patients with umbilical hernia have an increased likelihood of complications following repair. The aim of this study was to assess the outcomes of elective umbilical hernia repair in cirrhotic patients. Fifty patients having uncomplicated umbilical hernia with a cirrhotic liver were studied prospectively. These patients divided into three groups' according to Child-Turcotte-Pugh (CTP) classification. After management of coagulopathy, correction of hypoalbuminaemia and electrolytes imbalance, and control of ascites, all patients underwent elective hernia repair under regional anesthesia. A comparison was made between the three groups as regard the size of the defect in the linea Alba, operative time, postoperative morbidity and mortality, length of hospital stay, time of return to daily life and postoperative changes in liver function tests (LFTs) in relation to the regional anesthesia applied. hernioplasty was done under spinal anesthesia in 13 patients (26%), under epidural anesthesia in 10 patients (20%), under intercostal nerve block in 7 patients (14%), and under local anesthesia in 20 patients (40%). There was an increased safety (less changes in LFTs) in cases done under local anesthesia and intercostal nerve block. The overall complications rate was 30%. There was an increased complications rate towards the decompensated cases. The differences in the mean length of hospital stay and mean time of return to daily life are statistically significant between the three groups. Umbilical hernia recurrence rate was 2% and no mortality was reported in the study groups.

Testing of Anesthesia Machines and Defibrillators in Healthcare Institutions.

PubMed

Gurbeta, Lejla; Dzemic, Zijad; Bego, Tamer; Sejdic, Ervin; Badnjevic, Almir

2017-09-01

To improve the quality of patient treatment by improving the functionality of medical devices in healthcare institutions. To present the results of the safety and performance inspection of patient-relevant output parameters of anesthesia machines and defibrillators defined by legal metrology. This study covered 130 anesthesia machines and 161 defibrillators used in public and private healthcare institutions, during a period of two years. Testing procedures were carried out according to international standards and legal metrology legislative procedures in Bosnia and Herzegovina. The results show that in 13.84% of tested anesthesia machine and 14.91% of defibrillators device performance is not in accordance with requirements and should either have its results be verified, or the device removed from use or scheduled for corrective maintenance. Research emphasizes importance of independent safety and performance inspections, and gives recommendations for the frequency of inspection based on measurements. Results offer implications for adequacy of preventive and corrective maintenance performed in healthcare institutions. Based on collected data, the first digital electronical database of anesthesia machines and defibrillators used in healthcare institutions in Bosnia and Herzegovina is created. This database is a useful tool for tracking each device's performance over time.

Comparison of Adrenal Suppression between Etomidate and Dexmedetomidine in Children with Congenital Heart Disease.

PubMed

Gu, Hongbin; Zhang, Mazhong; Cai, Meihua; Liu, Jinfen

2015-05-29

The aim of this study was to compare plasma cortisol concentration during anesthesia of children with congenital heart disease who received dexmedetomidine (DEX) with those who received etomidate (ETO). We recruited 99 ASA physical status II-III pediatric patients scheduled for congenital heart disease (CHD) corrective surgery and divided into them into 3 groups. Group DEX received an infusion of DEX intravenously with a bolus dose of 0.5 µg·kg-1 within 10 min during anesthesia induction, followed by a maintenance dose of DEX 0.5 µg·kg-1·h-1. Group ETO received ETO intravenously with a bolus dose of 0.3 mg·kg-1 without a maintenance dose. Group CON received routine anesthetics as controls. The preset timepoints were: before anesthesia induction (T0), at the end of induction (T1), 30 min after anesthesia induction (T2), at the time of aortic and inferior vena catheterization (T3), and at 180 min (T4) and 24 h (T5) after anesthesia induction. The cortisol concentration decreased gradually after anesthesia induction in all groups, and returned to baseline values after 24 h. The cortisol concentration was significantly lower in Group ETO children than in Group DEX or group CON at T4. The plasma concentrations of cortisol decreased in CHD children after the operation, but returned to baseline after 24 h of anesthesia induction. The adrenal cortex function inhibition induced by ETO in CHD children is longer and more serious than that induced by DEX (if any) during the preoperative period.

Central Connections of the Lacrimal Functional Unit.

PubMed

Willshire, Catherine; Buckley, Roger J; Bron, Anthony J

2017-08-01

To study the contribution of each eye to the reflex tear response, after unilateral and bilateral topical anesthesia. A closed-eye, modified Schirmer test was performed bilaterally in 8 normal subjects, in a controlled environment chamber set to 23°C, 45% relative humidity, and 0.08 m/s airflow. Eye drops were instilled into each eye 10 minutes before the Schirmer test. Experiments were as follows: 1) bilateral saline (control), 2) unilateral anesthesia (ipsilateral anesthetic; contralateral saline), and 3) bilateral anesthesia. There was no difference in between-eye wetting lengths in the saline control eyes (P = 0.394) or the bilaterally anesthetized eyes (P = 0.171). The wetting length was reduced in both eyes after bilateral anesthesia compared with saline controls (P = 0.001; P ≤ 0.0005). After unilateral anesthesia, the wetting length was reduced in the anesthetized eye compared with its saline control by 51.4% (P ≤ 0.0005) and compared with its fellow, unanesthetized eye (P = 0.005). The fellow eye value was also reduced compared with its saline control (P = 0.06). The wetting length was reduced by topical anesthesia, when instilled bilaterally and ipsilaterally. The latter response implies an ipsilateral, reflex sensory drive to lacrimal secretion. In the unanesthetized fellow eye, the reduction compared with its saline control was not quite significant. This implies a relative lack of central, sensory, reflex cross-innervation, although the possibility cannot entirely be ruled out. These results are relevant to the possibility of reflex lacrimal compensation from a normal fellow eye, in cases of unilateral corneal anesthesia.

Infusion of guaifenesin, ketamine, and medetomidine in combination with inhalation of sevoflurane versus inhalation of sevoflurane alone for anesthesia of horses.

PubMed

Yamashita, Kazuto; Muir, William W; Tsubakishita, Sae; Abrahamsen, Eric; Lerch, Phillip; Izumisawa, Yasuharu; Kotani, Tadao

2002-10-15

To evaluate effects of infusion of guaifenesin, ketamine, and medetomidine in combination with inhalation of sevoflurane versus inhalation of sevoflurane alone for anesthesia of horses. Randomized clinical trial. 40 horses. Horses were premedicated with xylazine and anesthetized with diazepam and ketamine. Anesthesia was maintained by infusion of guaifenesin, ketamine, and medetomidine and inhalation of sevoflurane (20 horses) or by inhalation of sevoflurane (20 horses). A surgical plane of anesthesia was maintained by controlling the inhaled concentration of sevoflurane. Sodium pentothal was administered as necessary to prevent movement in response to surgical stimulation. Hypotension was treated with dobutamine; hypoxemia and hypercarbia were treated with intermittent positive-pressure ventilation. The quality of anesthetic induction, maintenance, and recovery and the quality of the transition to inhalation anesthesia were scored. The delivered concentration of sevoflurane (ie, the vaporizer dial setting) was significantly lower and the quality of transition to inhalation anesthesia and of anesthetic maintenance were significantly better in horses that received the guaifenesin-ketamine-medetomidine infusion than in horses that did not. Five horses, all of which received sevoflurane alone, required administration of pentothal. Recovery time and quality of recovery were not significantly different between groups, but horses that received the guaifenesin-ketamine-medetomidine infusion required fewer attempts to stand. Results suggest that in horses, the combination of a guaifenesin-ketamine-medetomidine infusion and inhalation of sevoflurane resulted in better transition and maintenance phases while improving cardiovascular function and reducing the number of attempts needed to stand after the completion of anesthesia, compared with inhalation of sevoflurane.

Anesthesia information management systems: a review of functionality and installation considerations.

PubMed

Ehrenfeld, Jesse M; Rehman, Mohamed A

2011-02-01

The functionality and rate of implementation of Anesthesia Information Management Systems (AIMS) has markedly risen over the past decade. These systems have now become much more than the generic automated record keepers, originally proposed and developed in the 1980s. AIMS have now become complex integrated systems, which have been shown to improve patient care and, in some cases, the financial performance of a department. Although the underlying technology has improved greatly over the past 5 years, the process of selecting and completing an AIMS installation still presents a number of challenges, and must be approached carefully in order to maximize the benefits provided by these systems.

Harmonic Brain Modes: A Unifying Framework for Linking Space and Time in Brain Dynamics.

PubMed

Atasoy, Selen; Deco, Gustavo; Kringelbach, Morten L; Pearson, Joel

2018-06-01

A fundamental characteristic of spontaneous brain activity is coherent oscillations covering a wide range of frequencies. Interestingly, these temporal oscillations are highly correlated among spatially distributed cortical areas forming structured correlation patterns known as the resting state networks, although the brain is never truly at "rest." Here, we introduce the concept of harmonic brain modes-fundamental building blocks of complex spatiotemporal patterns of neural activity. We define these elementary harmonic brain modes as harmonic modes of structural connectivity; that is, connectome harmonics, yielding fully synchronous neural activity patterns with different frequency oscillations emerging on and constrained by the particular structure of the brain. Hence, this particular definition implicitly links the hitherto poorly understood dimensions of space and time in brain dynamics and its underlying anatomy. Further we show how harmonic brain modes can explain the relationship between neurophysiological, temporal, and network-level changes in the brain across different mental states ( wakefulness, sleep, anesthesia, psychedelic). Notably, when decoded as activation of connectome harmonics, spatial and temporal characteristics of neural activity naturally emerge from the interplay between excitation and inhibition and this critical relation fits the spatial, temporal, and neurophysiological changes associated with different mental states. Thus, the introduced framework of harmonic brain modes not only establishes a relation between the spatial structure of correlation patterns and temporal oscillations (linking space and time in brain dynamics), but also enables a new dimension of tools for understanding fundamental principles underlying brain dynamics in different states of consciousness.

Influence of cadmium on ketamine-induced anesthesia and brain microsomal Na[sup +], K[sup +]-ATPase in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Y.; Sangiah, S.

1994-10-01

Cadmium is a rare metallic element, present in almost all types of food. Shellfish, wheat and rice accumulate very high amounts. Occupational and environmental pollutants are the main sources of cadmium exposure. Cadmium has a very long biologic half-life. Exposure to Cadmium causes anemia, hypertension, hepatic, renal, pulmonary and cardiovascular disorders as well as being a possible mutagen, teratogen and carcinogen. Acute cadmium treatment increased the hexobarbital sleeping time and inhibited hepatic microsomal drug metabolism due to a decrease in cytochrome P[sub 450] content. Cadmium potentiated ethanol-induced sleep in a dose-dependent manner. Cadmium has been shown to inhibit brain microsomalmore » Na[sup +], K[sup +]-ATPase activity in vitro and in vivo. Cadmium and ethanol additively inhibited brain Na[sup +], K[sup +]-ATPase. This might be a direct interaction between cadmium and ethanol in the central nervous system. Ketamine is an intravenous anesthetic agent. It acts on central nervous system and produces [open quotes]dissociative anaesthesia.[close quotes] Ketamine provides adequate surgical anesthesia and is used alone in humans and/or combination with xylazine, an [alpha][sub 2]-adrenergic agonist in animals. It produces CNS depression, analgesia, amnesia, immobility and a feeling of dissociation from the environment. Ketamine is a non-competitive antagonist of the NMDA subset of the glutamate receptor. This perhaps results in an increase in neuronal activity leading to disorganization of normal neurotransmission and produces dissociative anesthetic state. Because it is different from most other anesthetics, ketamine may be expected to have a unique effect on brain biochemical parameters and enzymes. The purpose of this study was to examine the interactions between cadmium and ketamine on the central nervous system and ATPase, in an attempt to further understand the mechanism of action. 12 refs., 3 figs.« less

Therapeutic effect of magnesium sulphate on carbon monoxide toxicity-mediated brain lipid peroxidation.

PubMed

Yavuz, Y; Mollaoglu, H; Yürümez, Y; Ucok, K; Duran, L; Tünay, K; Akgün, L

2013-02-01

Carbon monoxide (CO) toxicity primarily results from cellular hypoxia caused by impedance of oxygen delivery. Studies show that CO may cause brain lipid peroxidation and leukocyte-mediated inflammatory changes in the brain. The aim of this study was to investigate whether magnesium sulphate could prevent or diminish brain lipid peroxidation caused by carbon monoxide toxicity in rats. Fourty rats were divided into five groups of 8 rats each. Group l was not received any agent during the experiment. Group 2 was inhaled CO gas followed by intraperitoneally normal saline 30 minutes (min) later. Group 3 was inhaled CO gas followed by 100 mg/kg magnesium sulphate intraperitoneally 30 min later. Group 2 and Group 3 rats was undergone laparotomy and craniotomy while still under anesthesia at 6 hour, and tissue sample was obtained from the cerebrum. Group 4 was inhaled CO gas followed by intraperitoneally normal saline 30 min later. Group 5 was inhaled CO gas followed by 100 mg/kg magnesium sulphate intraperitoneally 30 min later. Group 4 and Group 5 rats was undergone laparotomy and craniotomy while still under anesthesia at 24 hour, and tissue sample was obtained from the cerebrum. Nitric oxide levels were no significantly different between all groups. Malonyldialdehyde levels increased in intoxication group (group 2) and decreased in treatment group (group 3). Activities of superoxide dismutase decreased in intoxication group (group 2) and increased in treatment group (group 3). Activities of catalase increased in intoxication group (group 2) and decreased in treatment group (group 3). Activities of glutathione peroxidase (GSH-Px) decreased in intoxication group (group 4) and increased in treatment group (group 5). CO poisoning caused significant damage, detected within the first 6 hours. Due to antioxidant enzymes, especially GSH-Px activity reaching the top level within 24th hours, significant oxidative damage was not observed. The protective effect against oxidative damage of magnesium sulfate has been identified within the first 6 hours.

TRIO Platform: A Novel Low Profile In vivo Imaging Support and Restraint System for Mice.

PubMed

Voziyanov, Vladislav; Kemp, Benjamin S; Dressel, Chelsea A; Ponder, Kayla; Murray, Teresa A

2016-01-01

High resolution, in vivo optical imaging of the mouse brain over time often requires anesthesia, which necessitates maintaining the animal's body temperature and level of anesthesia, as well as securing the head in an optimal, stable position. Controlling each parameter usually requires using multiple systems. Assembling multiple components into the small space on a standard microscope stage can be difficult and some commercially available parts simply do not fit. Furthermore, it is time-consuming to position an animal in the identical position over multiple imaging sessions for longitudinal studies. This is especially true when using an implanted gradient index (GRIN) lens for deep brain imaging. The multiphoton laser beam must be parallel with the shaft of the lens because even a slight tilt of the lens can degrade image quality. In response to these challenges, we have designed a compact, integrated in vivo imaging support system to overcome the problems created by using separate systems during optical imaging in mice. It is a single platform that provides (1) sturdy head fixation, (2) an integrated gas anesthesia mask, and (3) safe warm water heating. This THREE-IN-ONE (TRIO) Platform has a small footprint and a low profile that positions a mouse's head only 20 mm above the microscope stage. This height is about one half to one third the height of most commercially available immobilization devices. We have successfully employed this system, using isoflurane in over 40 imaging sessions with an average of 2 h per session with no leaks or other malfunctions. Due to its smaller size, the TRIO Platform can be used with a wider range of upright microscopes and stages. Most of the components were designed in SOLIDWORKS® and fabricated using a 3D printer. This additive manufacturing approach also readily permits size modifications for creating systems for other small animals.

TRIO Platform: A Novel Low Profile In vivo Imaging Support and Restraint System for Mice

PubMed Central

Voziyanov, Vladislav; Kemp, Benjamin S.; Dressel, Chelsea A.; Ponder, Kayla; Murray, Teresa A.

2016-01-01

High resolution, in vivo optical imaging of the mouse brain over time often requires anesthesia, which necessitates maintaining the animal's body temperature and level of anesthesia, as well as securing the head in an optimal, stable position. Controlling each parameter usually requires using multiple systems. Assembling multiple components into the small space on a standard microscope stage can be difficult and some commercially available parts simply do not fit. Furthermore, it is time-consuming to position an animal in the identical position over multiple imaging sessions for longitudinal studies. This is especially true when using an implanted gradient index (GRIN) lens for deep brain imaging. The multiphoton laser beam must be parallel with the shaft of the lens because even a slight tilt of the lens can degrade image quality. In response to these challenges, we have designed a compact, integrated in vivo imaging support system to overcome the problems created by using separate systems during optical imaging in mice. It is a single platform that provides (1) sturdy head fixation, (2) an integrated gas anesthesia mask, and (3) safe warm water heating. This THREE-IN-ONE (TRIO) Platform has a small footprint and a low profile that positions a mouse's head only 20 mm above the microscope stage. This height is about one half to one third the height of most commercially available immobilization devices. We have successfully employed this system, using isoflurane in over 40 imaging sessions with an average of 2 h per session with no leaks or other malfunctions. Due to its smaller size, the TRIO Platform can be used with a wider range of upright microscopes and stages. Most of the components were designed in SOLIDWORKS® and fabricated using a 3D printer. This additive manufacturing approach also readily permits size modifications for creating systems for other small animals. PMID:27199633

Effect of meloxicam and carprofen on renal function when administered to healthy dogs prior to anesthesia and painful stimulation.

PubMed

Crandell, Dawn E; Mathews, Karol A; Dyson, Doris H

2004-10-01

To determine whether administration of the nonsteroidal anti-inflammatory drugs meloxicam or carprofen to healthy dogs that were subsequently anesthetized and subjected to painful electrical stimulation has adverse effects on renal function as measured by glomerular filtration rate (GFR) and evaluation of serum concentrations of urea and creatinine. 6 male and 6 female healthy young-adult Beagles. A study was conducted in accordance with a randomized crossover Latin-square design. One of 3 treatments (saline [0.9% NaCl] solution, 0.2 mg of meloxicam/kg, or 4.0 mg of carprofen/kg) was administered i.v. 1 hour before anesthesia was induced by use of drugs in accordance with a standard anesthetic protocol (butorphanol tartrate and acepromazine maleate as preanesthetic medications, ketamine hydrochloride and diazepam for induction, and maintenance with isoflurane). Anesthetized dogs were subjected to intermittent electrical stimulation for 30 minutes. Direct, mean arterial blood pressure; heart rate; and respiratory rate were monitored. End-tidal isoflurane concentration was maintained at 1.5 times the minimum alveolar concentration. The GFR, as measured by plasma clearance of 99mTc-diethylenetriaminepentaacetic acid, and serum concentrations of serum and creatinine were determined 24 hours after induction of anesthesia. Neither meloxicam nor carprofen significantly affected GFR or serum concentrations of urea and creatinine, compared with values for the saline treatment. When administered 1 hour before onset of anesthesia and painful electrical stimulation, meloxicam or carprofen did not cause clinically important alterations of renal function in young healthy dogs.

Hyperexcitability of Rat Thalamocortical Networks after Exposure to General Anesthesia during Brain Development

PubMed Central

DiGruccio, Michael R.; Joksimovic, Srdjan; Joksovic, Pavle M.; Lunardi, Nadia; Salajegheh, Reza; Jevtovic-Todorovic, Vesna; Beenhakker, Mark P.; Goodkin, Howard P.

2015-01-01

Prevailing literature supports the idea that common general anesthetics (GAs) cause long-term cognitive changes and neurodegeneration in the developing mammalian brain, especially in the thalamus. However, the possible role of GAs in modifying ion channels that control neuronal excitability has not been taken into consideration. Here we show that rats exposed to GAs at postnatal day 7 display a lasting reduction in inhibitory synaptic transmission, an increase in excitatory synaptic transmission, and concomitant increase in the amplitude of T-type calcium currents (T-currents) in neurons of the nucleus reticularis thalami (nRT). Collectively, this plasticity of ionic currents leads to increased action potential firing in vitro and increased strength of pharmacologically induced spike and wave discharges in vivo. Selective blockade of T-currents reversed neuronal hyperexcitability in vitro and in vivo. We conclude that drugs that regulate thalamic excitability may improve the safety of GAs used during early brain development. PMID:25632125

A Case of Subclavian Artery Aneurysm with History of Ischemic Heart Disease Operated Under Cervical Epidural Anesthesia.

PubMed

Rath, Amrita; Abhinay, J; Loha, Sandeep; Singh, Atul Kumar

2017-01-01

Subclavian artery aneurysm is usually operated under general anesthesia (GA), but in specific situations, it can also be conducted under regional anesthesia (RA) such as cervical epidural anesthesia (CEA). A 48-year-old male presented with chief complaint of progressive swelling in the right side of the neck for the past 3 months following trauma. He was diagnosed as subclavian artery aneurysm, and surgical intervention was advised. He had previous history of angina 4 months back for which tablet aspirin 75 mg and tablet clopidogrel 75 mg once daily was prescribed. Cardiological evaluation revealed of an ejection fraction of around 30% with mild left ventricular hypokinesia and grade 2 diastolic dysfunction. Due to the poor cardiac functional status of the patient, RA with CEA was planned. The risk with GA in cases with a history of myocardial ischemia is more than RA, hence, it is better to use CEA which is equally efficacious in such high-risk cases.

Audit of the Functioning of the Elective Neurosurgical Operation Theater in India: A Prospective Study and Review of Literature.

PubMed

Saikia, Amrit Kumar; Sriganesh, Kamath; Ranjan, Manish; Claire, Marie; Mittal, Mohit; Pandey, Paritosh

2015-08-01

Knowledge about the utilization of the operation theater (OT) is essential to improve its efficiency. This study evaluated the neurosurgical operation theater utilization in a neurosciences teaching hospital. Data collected included OT start time, delay in start, anesthesia induction time, surgical preparation time, anesthesia recovery time, operating time, time between cases, and theater closing time. Five hundred thirty-seven surgeries were performed during the study period. The percentage of time used for anesthesia induction, actual surgical procedure, recovery from anesthesia, and theater preparation between the two cases were 8%, 70%, 6% and 5%, respectively. Fourteen percent of scheduled cases were cancelled. On 220 occasions (70.51%), theater was over-run. Late start contributed to loss of 8370 minutes (140 hours) of theater time. This study identified the proportion of time spent on each activity in the neurosurgical OT. This knowledge is likely to facilitate better planning of neurosurgical theater schedule and result in optimal utilization. Copyright © 2015 Elsevier Inc. All rights reserved.

Anorectal manometry with and without ketamine for evaluation of defecation disorders in children.

PubMed

Keshtgar, A S; Choudhry, M S; Kufeji, D; Ward, H C; Clayden, G S

2015-03-01

Anorectal manometry (ARCM) provides valuable information in children with chronic constipation and fecal incontinence but may not be tolerated in the awake child. This study aimed to evaluate the effect of ketamine anesthesia on the assessment of anorectal function by manometry and to evaluate defecation dynamics and anal sphincter resting pressure in the context of pathophysiology of chronic functional (idiopathic) constipation and soiling in children. This was a prospective study of children who were investigated for symptoms of chronic constipation and soiling between April 2001 and April 2004. We studied 52 consecutive children who had awake ARCM, biofeedback training and endosonography (awake group) and 64 children who had ketamine anesthesia for ARCM and endosonography (ketamine group). We age matched 31 children who had awake anorectal studies with 27 who had ketamine anesthesia. The children in awake and ketamine groups were comparable for age, duration of bowel symptoms and duration of laxative treatments. ARCM profile was comparable between the awake and the ketamine groups with regard to anal sphincter resting pressure, rectal capacity, amplitude of rectal contractions, frequency of rectal and IAS contractions and functional length of anal canal. Of 52 children who had awake ARCM, dyssynergia of the EAS muscles was observed in 22 (42%) and median squeeze pressure was 87mm Hg (range 25-134). The anal sphincter resting pressure was non-obstructive and comparable to healthy normal children. Rectoanal inhibitory reflex was seen in all children excluding diagnosis of Hirschsprung disease. Ketamine anesthesia does not affect quantitative or qualitative measurements of autonomic anorectal function and can be used reliably in children who will not tolerate the manometry while awake. Paradoxical contraction of the EAS can only be evaluated in the awake children and should be investigated further as the underlying cause of obstructive defecation in patients with chronic functional constipation and soiling. Copyright © 2015 Elsevier Inc. All rights reserved.

[Acute asthma attacks introduced by anesthesia before nasal endoscopic surgery].

PubMed

Lü, Xiaofei; Han, Demin; Zhou, Bing; Ding, Bin

2004-05-01

In order to pay our attention to the perioperative treatment before nasal endoscopic surgery. Three patients with asthma accompanied chronic sinusitis were analyzed systemically, who had undergone acute attacks of asthma introduced by anesthesia. Anesthetic drugs and instruments can lead to acute attacks of asthma, because sinusitis with asthma means allergic airway inflammation, broncho-hyperreactivity and lower compensatory pulmonary function. Then all of the 3 cases had missed the preoperative treatment. Anesthetic drugs and instruments can lead to acute attacks of asthma. The perioperative treatment before nasal endoscopic surgery is very important for the prevention of the occurrences of this severe complication. Except emergency, the operation should be can celled for avoiding the acute attack of asthma introduced by anesthesia.

InVivo Imaging of Myelination for Drug Discovery and Development in Multiple Sclerosis

DTIC Science & Technology

2012-10-01

oligodendrocyte precursor cells, which are subsequently activated and distributed to the damaged axons. However, the remyelination process is often disrupted in...emitting carbon -11, and used for PET imaging of myelination (Wu et al., 2008; Wu et al., 2010). We demonstrated that [11C]MeDAS can readily penetrate...conducted. The animals were killed by a transcardial perfusion of saline followed by 4% polyformaldhyde ( PFA ) under anesthesia. The spinal cord and brain

Trehalose protects from aggravation of amyloid pathology induced by isoflurane anesthesia in APP(swe) mutant mice.

PubMed

Perucho, Juan; Casarejos, Maria J; Gomez, Ana; Solano, Rosa M; de Yébenes, Justo Garcia; Mena, Maria A

2012-03-01

There is an open controversy about the role of surgery and anesthesia in the pathogenesis of Alzheimer's disease (AD). Clinical studies have shown a high prevalence of these procedures in subjects with AD but the interpretation of these studies is difficult because of the co-existence of multiple variables. Experimental studies in vitro and in vivo have shown that small molecular weight volatile anesthetics enhance amyloidogenesis in vitro and produce behavioral deficits and brain lesions similar to those found in patients with AD. We examined the effect of co-treatment with trehalose on isoflurane-induced amyloidogenesis in mice. WT and APP(swe) mice, of 11 months of age, were exposed to 1% isoflurane, 3 times, for 1.5 hours each time and sacrificed 24 hours after their last exposure to isoflurane. The right hemi-brain was used for histological analysis and the contra-lateral hemi-brain used for biochemical studies. In this study, we have shown that repetitive exposure to isoflurane in pre-symptomatic mature APP(swe) mice increases apoptosis in hippocampus and cerebral cortex, enhances astrogliosis and the expression of GFAP and that these effects are prevented by co-treatment with trehalose, a disaccharide with known effects as enhancer of autophagy. We have also confirmed that in our model the co-treatment with trehalose increases the expression of autophagic markers as well as the expression of chaperones. Cotreatment with trehalose reduces the levels of β amyloid peptide aggregates, tau plaques and levels of phospho-tau. Our study, therefore, provides new therapeutic avenues that could help to prevent the putative pro-amyloidogenic properties of small volatile anesthetics.

Dual-labeling with 5-aminolevulinic acid and fluorescein for fluorescence-guided resection of high-grade gliomas: technical note.

PubMed

Suero Molina, Eric; Wölfer, Johannes; Ewelt, Christian; Ehrhardt, André; Brokinkel, Benjamin; Stummer, Walter

2018-02-01

OBJECTIVE Fluorescence guidance with 5-aminolevulinic acid (5-ALA) helps improve resections of malignant gliomas. However, one limitation is the low intensity of blue light for background illumination. Fluorescein has recently been reintroduced into neurosurgery, and novel microscope systems are available for visualizing this fluorochrome, which highlights all perfused tissues but has limited selectivity for tumor detection. Here, the authors investigate a combination of both fluorochromes: 5-ALA for distinguishing tumor and fluorescein for providing tissue fluorescence of adjacent brain tissue. METHODS The authors evaluated 6 patients who harbored cerebral lesions suggestive of high-grade glioma. Patients received 5-ALA (20 mg/kg) orally 4 hours before induction of anesthesia. Low-dose fluorescein (3 mg/kg intravenous) was injected immediately after anesthesia induction. Pentero microscopes (equipped either with Yellow 560 or Blue 400 filters) were used to visualize fluorescence. To simultaneously visualize both fluorochromes, the Yellow 560 module was combined with external blue light illumination (D-light C System). RESULTS Fluorescein-induced fluorescence created a useful background for protoporphyrin IX (PPIX) fluorescence, which appeared orange to red, surrounded by greenly fluorescent normal brain and edematous tissue. Green brain-tissue fluorescence was helpful in augmenting background. Levels of blue illumination that were too strong obscured PPIX fluorescence. Unspecific extravasation of fluorescein was noted at resection margins, which did not interfere with PPIX fluorescence detection. CONCLUSIONS Dual labeling with both PPIX and fluorescein fluorescence is feasible and gives superior background information during fluorescence-guided resections. The authors believe that this technique carries potential as a next step in fluorescence-guided resections if it is completely integrated into the surgical microscope.

Preoperative assessment and preparation of patients with diseases affecting the central nervous system.

PubMed

Milaković, Branko; Dimitrijević, Ivan; Malenković, Vesna; Marković, Dejan; Pantić-Palibrk, Vesna; Gvozdenović, Ljiljana

2011-01-01

This review will examine the most important issues of preoperative evaluation and preparation in relation to patients with deseases affecting the central nervous system. Those patients may undergo various forms of surgery unrelated to the central nervous system disease. We discuss the effect of physiologic and pharmacological factors on cerebral autoregulation and control of intracranial pressure alongside its clinical relevance with the help of new evidence. Regardless of the reason for surgery, coexisting diseases of brain often have important implications when selecting anesthetic drugs, procedures and monitoring techniques. Suppression of cerebral metabolic rate is not the sole mechanism for the neuroprotective effect of anaesthetic agents. There are certain general principles, but also some specific circumstances, when we are talking about optimal anesthetic procedure for a patient with coexisting brain disease. Intravenous anesthesia, such as combination of propofol and remifentanil, provides best preservation of autoregulation. Among inhaled agents isoflurane and sevoflurane appear to preserve autoregulation at all doses, whereas with other agents autoregulation is impaired in a dose-related manner. During maintenance of anesthesia the patient is ventilated by intermittent positive pressure ventilation, at intermediate hyperventilation (PaCO2 25-30 mmHg). Intraoperative cerebral autoregulation monitoring is an important consideration for the patients with coexisting neurological disease. Transcranial Doppler based static autoregulation measurements appears to be the most robust bedside method for this purpose.

Mechanisms of Anesthetic Action and Neurotoxicity: Lessons from Molluscs

PubMed Central

Armstrong, Ryden; Riaz, Saba; Hasan, Sean; Iqbal, Fahad; Rice, Tiffany; Syed, Naweed

2018-01-01

Anesthesia is a prerequisite for most surgical procedures in both animals and humans. Significant strides have been made in search of effective and safer compounds that elicit rapid induction and recovery from anesthesia. However, recent studies have highlighted possible negative effects of several anesthetic agents on the developing brain. The precise nature of this cytotoxicity remains to be determined mainly due to the complexity and the intricacies of the mammalian brain. Various invertebrates have contributed significantly toward our understanding of how both local and general anesthetics affect intrinsic membrane and synaptic properties. Moreover, the ability to reconstruct in vitro synapses between individually identifiable pre- and postsynaptic neurons is a unique characteristic of molluscan neurons allowing us to ask fundamental questions vis-à-vis the long-term effects of anesthetics on neuronal viability and synaptic connectivity. Here, we highlight some of the salient aspects of various molluscan organisms and their contributions toward our understanding of the fundamental mechanisms underlying the actions of anesthetic agents as well as their potential detrimental effects on neuronal growth and synaptic connectivity. We also present some novel preliminary data regarding a newer anesthetic agent, dexmedetomidine, and its effects on synaptic transmission between Lymnaea neurons. The findings presented here underscore the importance of invertebrates for research in the field of anesthesiology while highlighting their relevance to both vertebrates and humans. PMID:29410627

Disconnecting Consciousness: Is There a Common Anesthetic End Point?

PubMed

Hudetz, Anthony G; Mashour, George A

2016-11-01

A quest for a systems-level neuroscientific basis of anesthetic-induced loss and return of consciousness has been in the forefront of research for the past 2 decades. Recent advances toward the discovery of underlying mechanisms have been achieved using experimental electrophysiology, multichannel electroencephalography, magnetoencephalography, and functional magnetic resonance imaging. By the careful dosing of various volatile and IV anesthetic agents to the level of behavioral unresponsiveness, both specific and common changes in functional and effective connectivity across large-scale brain networks have been discovered and interpreted in the context of how the synthesis of neural information might be affected during anesthesia. The results of most investigations to date converge toward the conclusion that a common neural correlate of anesthetic-induced unresponsiveness is a consistent depression or functional disconnection of lateral frontoparietal networks, which are thought to be critical for consciousness of the environment. A reduction in the repertoire of brain states may contribute to the anesthetic disruption of large-scale information integration leading to unconsciousness. In future investigations, a systematic delineation of connectivity changes with multiple anesthetics using the same experimental design, and the same analytical method will be desirable. The critical neural events that account for the transition between responsive and unresponsive states should be assessed at similar anesthetic doses just below and above the loss or return of responsiveness. There will also be a need to identify a robust, sensitive, and reliable measure of information transfer. Ultimately, finding a behavior-independent measure of subjective experience that can track covert cognition in unresponsive subjects and a delineation of causal factors versus correlated events will be essential to understand the neuronal basis of human consciousness and unconsciousness.

Disconnecting Consciousness: Is There a Common Anesthetic End-Point?

PubMed Central

Hudetz, Anthony G.; Mashour, George A.

2016-01-01

A quest for a systems-level neuroscientific basis of anesthetic-induced loss and return of consciousness has been in the forefront of research of the last two decades. Recent advances toward the discovery of underlying mechanisms have been achieved using experimental electrophysiology, multichannel electroencephalography, magnetoencephalography, and functional magnetic resonance imaging. By the careful dosing of various volatile and IV anesthetic agents to the level of behavioral unresponsiveness, both specific and common changes in functional and effective connectivity across large-scale brain networks have been discovered and interpreted in the context of how the synthesis of neural information might be affected during anesthesia. The results of most investigations to date converge toward the conclusion that a common neural correlate of anesthetic-induced unresponsiveness is a consistent depression or functional disconnection of lateral frontoparietal networks, which are thought to be critical for consciousness of the environment. A reduction in the repertoire of brain states may contribute to the anesthetic disruption of large-scale information integration leading to unconsciousness. In future investigations, a systematic delineation of connectivity changes with multiple anesthetics using the same experimental design and the same analytical method will be desirable. The critical neural events that account for the transition between responsive and unresponsive states should be assessed at similar anesthetic doses just below and above the loss or return of responsiveness. There will also be a need to identify a robust, sensitive, and reliable measure of information transfer. Ultimately, finding a behavior-independent measure of subjective experience that can track covert cognition in unresponsive subjects and a delineation of causal factors vs. correlated events will be essential to understand the neuronal basis of human consciousness and unconsciousness. PMID:27331780

Cardiopulmonary effects of thiopental versus propofol as an induction agent prior to isoflurane anesthesia in chair trained rhesus macaques (Macaca mulatta).

PubMed

Choi, Yun-Jung; Park, Hye-Jin; Kim, Hyeon-Ho; Lee, Yun-Jin; Jung, Kyeong-Cheon; Park, Seong-Hoe; Lee, Jae-Il

2016-03-01

The purpose of this study was to evaluate the effects of thiopental versus propofol on cardiopulmonary functions, when used as an induction agent prior to isoflurane anesthesia in rhesus monkeys. Eight healthy rhesus monkeys weighing 3.72 to 5.7 kg, 4-5 years old, were used in the study. Anesthesia was induced with thiopental or propofol intravenous injection, and then maintained with isoflurane in oxygen for 45 minutes. Cardiopulmonary measurements were obtained before and 5, 15, 30, 45, and 60 minutes after induction. The induction doses of thiopental and propofol were 19.41±0.54 and 9.33±1.02 mg/kg, respectively. In both groups, the values of heart rate, respiratory rate, temperature, systolic blood pressure, mean blood pressure, diastolic blood pressure, pH, and lactate were decreased, while the values of partial pressure of carbon dioxide, partial pressure of oxygen, total carbon dioxide, bicarbonate, oxygen saturation, and base excess in the extracellular fluid were increased, as compared with baseline. Systolic blood pressure was significantly lower in thiopental group compare to propofol group. Induction time was very short in both agents but not revealed a significant difference between both groups. However, recovery time was extremely faster in the propofol group. Our results demonstrated that propofol provides a minor suppression in systolic arterial blood pressure than thiopental sodium. In addition, propofol have a fast recovery effect from the anesthesia as well. Furthermore, it is suggested that thiopental sodium could also be used to induce anesthesia instead of propofol, despite slight more suppression of cardiopulmonary function compared to thiopental sodium.

[Oxygen-transporting function of the blood circulation system in sevoflurane anesthesia during myocardial revascularization under extracorporeal circulation].

PubMed

Skopets, A A; Lomivorotov, V V; Karakhalis, N B; Makarov, A A; Duman'ian, E S; Lomivorotova, L V

2009-01-01

The purpose of the study was to evaluate the efficiency of oxygen-transporting function of the circulatory system under sevoflurane anesthesia during myocardial revascularization operations under extracorporeal circulation. Twenty-five patients with coronary heart disease were examined. Mean blood pressure, heart rate, cardiac index, total peripheral vascular resistance index, pulmonary pressure, pulmonary wedge pressure, and central venous pressure were measured. Arterial and mixed venous blood oxygen levels, oxygen delivery and consumption index, arteriovenous oxygen difference, and glucose and lactate concentrations were calculated. The study has demonstrated that sevoflurane is an effective and safe anesthetic for myocardial revascularization operations in patients with coronary heart disease. The use of sevoflurane contributes to steady-state oxygen-transporting function of the circulatory system at all surgical stages.

Urinary extracorporeal shock wave lithotripsy: equipment, techniques, and overview.

PubMed

Pfister, R C; Papanicolaou, N; Yoder, I C

1988-01-01

Second generation urinary lithotriptors are characterized by extensive technical alterations and significant equipment improvement in the functional, logistical, and medical aspects of shock wave lithotripsy (SWL). These newer devices feature a water bath-free environment, a reduced anesthesia requirement, improved imaging, functional uses in addition to lithotripsy, or combinations thereof. Shock wave generation by spark gap, electromagnetic, piezoelectric and microexplosive techniques are related to their peak energy, frequency, and total energy capabilities which impacts on both anesthesia needs and the length and number of treatment sessions required to pulverize calculi. A master table summarizes the types of SW energy, coupling, imaging systems, patient transport, functional features, cost, and treatment effectiveness of 12 worldwide lithotriptors in various stages of investigative and clinical trials as monitored by the Food and Drug Administration (FDA) of America.

[Anesthesia and Consciousness].

PubMed

Ogino, Yuichi; Kawamichi, Hiroaki; Saiot, Shigeru

2016-05-01

The mechanism of consciousness and loss of conciousness by general anesthetics are crucial issue for the anesthesiologists. Recent non-invasive brain-imaging technology brings about light to various our emotions and sensations in human brain; however, neural correlate of consciousness is not yet still elucidated. The concept "the seat of the consciousness (is in the subcortical nuclei)" is now completely denied, but instead the consciousness is based on the idea that connectivity and communications across cortical and thalamocortical networks. Anesthetics and sleep disrupt the networks that encompass complexity and integration. The compatibility between complexity and integration is the key feature of the consciousness, which is represented by complex, extensive, communicative and integrative electroencephalograph currents evoked by transcranial magnetic stimulation, provoking a single unified conscious experience in us, humans.

Low Dose Isoflurane Exerts Opposing Effects on Neuronal Network Excitability in Neocortex and Hippocampus

PubMed Central

Ranft, Andreas; von Meyer, Ludwig; Zieglgänsberger, Walter; Kochs, Eberhard; Dodt, Hans-Ulrich

2012-01-01

The anesthetic excitement phase occurring during induction of anesthesia with volatile anesthetics is a well-known phenomenon in clinical practice. However, the physiological mechanisms underlying anesthetic-induced excitation are still unclear. Here we provide evidence from in vitro experiments performed on rat brain slices that the general anesthetic isoflurane at a concentration of about 0.1 mM can enhance neuronal network excitability in the hippocampus, while simultaneously reducing it in the neocortex. In contrast, isoflurane tissue concentrations above 0.3 mM expectedly caused a pronounced reduction in both brain regions. Neuronal network excitability was assessed by combining simultaneous multisite stimulation via a multielectrode array with recording intrinsic optical signals as a measure of neuronal population activity. PMID:22723999

Serum inorganic fluoride and renal function in dogs after methoxyflurane anesthesia, tetracycline treatment, and surgical manipulation.

PubMed

Fleming, J T; Pedersoli, W M

1980-12-01

Effects of 2 hours of methoxyflurane-induced anesthesia in 25 dogs were determined by serum inorganic fluoride, serum urea nitrogen, serum creatinine, water intake, urine excretion, and urine specific gravity measurements; arterial concentrations of the anesthetic were also determined. The dogs were allotted to 5 groups (PTM, CTM, PTML, CTML, ML) of 5 dogs in each group and were anesthetized (M, in group designations) for 2 hours. The dogs were injected with chemically pure tetracycline or commercial tetracycline (PT and CT, in group designations) before, on the day of, and after anesthesia. In 3 groups, laparotomy (L, in group designations) was done; group ML did not receive tetracycline but a laparotomy was performed. Serum inorganic fluoride increased (P less than 0.05) in all groups 24 hours after anesthesia when compared with the base-line values; the highest mean serum concentration was 81.1 +/- 7.91 mumol/L (group PTM) and the lowest was 32.7 +/- 4.53 mumol/L (group PTML). There was no difference (P greater than 0.05) seen in serum urea nitrogen concentrations between groups. Methoxyflurane and tetracycline treatment caused no difference (P greater than 0.05) on serum concentrations of inorganic fluoride and urea nitrogen. Serum creatinine concentrations differed (P less than 0.05) only for groups PTM, CTM, PTML, and CTML vs group ML. Water intake reached peak at 48 hours after anesthesia. Arterial concentrations of methoxyflurane determined at 60 and 120 minutes of anesthesia indicated no difference (P greater than 0.05) among groups. Neither clinical nor laboratory signs of severe kidney dysfunction were detected in any of the experimental dogs during a 5-day observation period after anesthesia.

A prospective double blinded randomized study of anterior cruciate ligament reconstruction with hamstrings tendon and spinal anesthesia with or without femoral nerve block.

PubMed

Astur, Diego Costa; Aleluia, Vinicius; Veronese, Ciro; Astur, Nelson; Oliveira, Saulo Gomes; Arliani, Gustavo Gonçalves; Badra, Ricardo; Kaleka, Camila Cohen; Amaro, Joicemar Tarouco; Cohen, Moisés

2014-10-01

Current literature supports the thought that anesthesia and analgesia administered perioperatively for an anterior cruciate ligament (ACL) reconstruction have a great influence on time to effective rehabilitation during the first week after hospital discharge. The aim of this study is to answer the research question is there a difference in clinical outcomes between the use of a femoral nerve block with spinal anesthesia versus spinal analgesia alone for people undergoing ACL reconstruction? ACL reconstruction with spinal anesthesia and patient sedation (Group one); and spinal anesthesia with patient sedation and an additional femoral nerve block (Group two). Patients were re-evaluated for pain, range of motion (ROM), active contraction of the quadriceps, and a Functional Independence Measure (FIM) scoring scale. Spinal anesthesia with a femoral nerve block demonstrates pain relief 6h after surgery (VAS 0.37; p=0.007). From the third (VAS=4.56; p=0.028) to the seventh (VAS=2.87; p=0.05) days after surgery, this same nerve blockage delivered higher pain scores. Patients had a similar progressive improvement on knee joint range of motion with or without femoral nerve block (p<0.002). Group one and two had 23.75 and 24.29° 6h after surgery and 87.81 and 85.36° of knee flexion after 48h post op. Spinal anesthesia associated with a femoral nerve block had no additional benefits on pain control after the third postoperative day. There were no differences between groups concerning ability for knee flexion and to complete daily activities during postoperative period. Randomized Clinical Trial Level I. Copyright © 2014 Elsevier B.V. All rights reserved.

Behavioral analysis of children's response to induction of anesthesia.

PubMed

Chorney, Jill MacLaren; Kain, Zeev N

2009-11-01

It is documented that children experience distress at anesthesia induction, but little is known about the prevalence of specific behaviors exhibited by children. Digital audiovisual recordings of 293 children undergoing outpatient elective surgery were coded using Observer XT software and the validated Revised Perioperative Child-Adult Medical Procedure Interaction Scale. Multiple pass second-by-second data recording was used to capture children's behaviors across phases of anesthesia induction. More than 40% of children aged 2-10 yr displayed some distress behavior during induction with 17% of these children displaying significant distress and more than 30% of children resisting anesthesiologists during induction. Children's distress and nondistress behaviors displayed four profiles over the course of anesthesia induction: Acute Distress, Anticipatory Distress, Early Regulating Behaviors, and Engagement with Procedure. Older children had higher scores on early regulating and engagement profiles whereas younger children had higher scores on Acute Distress. There were no differences across age in children's Anticipatory Distress. Construct validity of behavior profiles was supported via correlations of profile score (overall and on the walk to the operating room) with a validated assessment of children's anxiety at induction. Children undergoing anesthesia display a range of distress and nondistress behaviors. A group of behaviors was identified that, when displayed on the walk to the operating room, is associated with less distress at anesthesia induction. These data provide the first examination of potentially regulating behaviors of children, but more detailed sequential analysis is required to validate specific functions of these behaviors.

Gait abnormalities caused by selective anesthesia of the suprascapular nerve in horses.

PubMed

Devine, Dustin V; Jann, Henry W; Payton, Mark E

2006-05-01

To assess gait abnormalities associated with selective anesthesia of the suprascapular nerve (SSN) achieved by use of perineural catheterization and thereby determine the function of that nerve as it relates to gait in horses. 3 adult horses with no preexisting clinically apparent lameness at a walk. Each horse was anesthetized; the right SSN was exposed surgically for placement of a perineural catheter to permit delivery of 1 mL of 2% mepivacaine hydrochloride. Six hours after recovery from anesthesia, each horse was videotaped while walking (50-step data acquisition period) before and after administration of mepivacaine. Videotapes were reviewed and the proportion of abnormal steps before and after selective SSN anesthesia was assessed. A step was considered abnormal if a marked amount of scapulohumeral joint instability (ie, lateral luxation of the proximal portion of the humerus) was observed during the weight-bearing phase of the stride. Clinically apparent gait dysfunction was detected in all 3 horses following perineural administration of the local anesthetic agent. Anesthesia of the SSN resulted in scapulohumeral joint instability as evidenced by consistent lateral excursion of the shoulder region during the weight-bearing phase of gait at a walk. The proportion of abnormal steps before and after SSN anesthesia was significantly different in all 3 horses. These data support the role of the SSN in shoulder joint stability in horses and define SSN dysfunction as 1 mechanism by which the syndrome and gait dysfunction clinically referred to as sweeny may develop.

Awake Craniotomy Anesthesia: A Comparison of the Monitored Anesthesia Care and Asleep-Awake-Asleep Techniques.

PubMed

Eseonu, Chikezie I; ReFaey, Karim; Garcia, Oscar; John, Amballur; Quiñones-Hinojosa, Alfredo; Tripathi, Punita

2017-08-01

Commonly used sedation techniques for an awake craniotomy include monitored anesthesia care (MAC), using an unprotected airway, and the asleep-awake-asleep (AAA) technique, using a partially or totally protected airway. We present a comparative analysis of the MAC and AAA techniques, evaluating anesthetic management, perioperative outcomes, and complications in a consecutive series of patients undergoing the removal of an eloquent brain lesion. Eighty-one patients underwent awake craniotomy for an intracranial lesion over a 9-year period performed by a single-surgeon and a team of anesthesiologists. Fifty patients were treated using the MAC technique, and 31 were treated using the AAA technique. A retrospective analysis evaluated anesthetic management, intraoperative complications, postoperative outcomes, pain management, and complications. The MAC and AAA groups had similar preoperative patient and tumor characteristics. Mean operative time was shorter in the MAC group (283.5 minutes vs. 313.3 minutes; P = 0.038). Hypertension was the most common intraoperative complication seen (8% in the MAC group vs. 9.7% in the AAA group; P = 0.794). Intraoperative seizure occurred at a rate of 4% in the MAC group and 3.2% in the AAA group (P = 0.858). Awake cases were converted to general anesthesia in no patients in the MAC group and in 1 patient (3.2%) in the AAA group (P = 0.201). No cases were aborted in either group. The mean hospital length of stay was 3.98 days in the MAC group and 3.84 days in the AAA group (P = 0.833). Both the MAC and AAA sedation techniques provide an efficacious and safe method for managing awake craniotomy cases and produce similar perioperative outcomes, with the MAC technique associated with shorter operative time. Copyright © 2017 Elsevier Inc. All rights reserved.

A survey of anesthesiologists' role, trust in anesthesiologists, and knowledge and fears about anesthesia among predominantly Hispanic patients from an inner-city county preoperative anesthesia clinic.

PubMed

Nagrampa, Dustin; Bazargan-Hejazi, Shahrzad; Neelakanta, Gundappa; Mojtahedzadeh, Mona; Law, Adrienne; Miller, Margaret

2015-03-01

To determine the difference between the Hispanic and non-Hispanic public's knowledge about anesthesia, anesthesiologist's expertise, and role of the anesthesiologist in and out of the operating room (OR). Cross-sectional survey. Los Angeles inner-city county hospital preoperative anesthesia clinic. Predominantly Hispanic population. A 54-question survey in English and Spanish was distributed to adult patients. Demographic data, knowledge of the anesthesiologist's roles/responsibilities, knowledge of anesthesia, trust in anesthesiologists, and fears related to anesthesia were collected. Descriptive analysis and multiple regression analysis of the data were used to report knowledge, trust, and fear, and the predictive role of patient characteristics. 300 (88% of eligible pts) completed the survey. Patient demographics were as follows: Hispanics (73%), female (63%), mean age 47 ± 14 years, high school-educated or below (71%), previous surgery (67%), possessing a chronic medical condition (49%), self-reported health of fair to poor (58%). Seventy percent of patients recognized anesthesiologists as specially trained doctors. Mean ± SD trust scores in doctors were 2.6 ± 1.2 out of a maximum 4. Patients with a better perception of their self-health (P < 0.01) and with higher knowledge scores (P < 0.01) had significantly higher trust in the doctors. Women (P = 0.01) patients, those patients with chronic medical condition (P < 0.02), and patients with greater knowledge scores had greater fear or concerns about anesthesia. Mean ± SD knowledge score about anesthesia was 6.3 ± 2.8 (range 0-13). Patients who had surgery previously (P < 0.01) had higher knowledge scores. Most Hispanic patients believe that anesthesiologists are specialist doctors and that they put patients to sleep, but these patients are uncertain of their exact role or function during surgery or outside of the OR. High concerns or fears about devastating but rare complications of anesthesia remain. Educational efforts should be directed at this group especially, with the goal of alleviating preoperative anxiety. Copyright © 2014 Elsevier Inc. All rights reserved.

Survey of the sevoflurane sedation status in one provincial dental clinic center for the disabled.

PubMed

Park, Chang-Hyun; Kim, Seungoh

2016-12-01

Sevoflurane sedation in pediatric and disabled patients has the advantage of faster induction and recovery compared to general anesthesia, as well as minimum influence on the respiratory and cardiovascular functions, and airway protective reflexes. This study aimed to evaluate the clinical efficacy of sevoflurane sedation used in dental treatment at one provincial dental clinic center for the disabled. We investigated patients' gender, age, reasons for undergoing sedation, medication history prior to treatment, duration of anesthesia, treatment length, type of treatment, and yearly patterns, for 387 cases of dental treatment performed using sevoflurane sedation from January 2013 to October 2016. We analyzed 387 cases (215 male patients, 172 female patients). Male patients aged 20 year or older accounted for 39.0% of all patients, marking the highest proportion. Patient's lack of cooperation was the most common reason for performing dental sedation. Prosthetic treatment was the most frequently practiced, accounting for 174 treatment cases. The mean lengths of the entire treatment and of the dental procedure were 55.2 min and 39.8 min, respectively. Sevoflurane sedation has the advantage of fast anesthesia induction and recovery compared to general anesthesia; therefore, it can be used efficiently to induce anesthesia in pediatric and disabled patients during short dental procedures, enabling stable treatment of these patients.

[EFFECTS OF CANNABIS EXTRACT PREMEDICATION ON ANESTHETIC DEPTH].

PubMed

Ibera, Carlos; Shalom, Ben; Saifi, Fayez; Shruder, Joshua; Davidson, Elyad

2018-03-01

Cannabis is the most widely used illicit drug in the world, used by approximately 2.7-4.9% of the world's population, and 7.6-10.2% of Israel's adults. During the past few years, legal systems around the world have enacted large scale adoption of the legalization of both medical and recreational cannabis. Anesthetists should therefore be prepared to treat patients who used cannabis and are undergoing elective or emergency operations. However, the interactions between cannabinoids and general anesthetic agents and the possible implications for patient care are not yet fully understood. The study aimed to examine how preoperative use of cannabis affects the anesthesia process, and whether this use requires special attention by the anesthesiologists during surgery. Hence, we examined the effect of preoperative administration of cannabis extract Sativex (nabiximols) on obtained BIS value relative to the concentration of anesthetic gases. This study is a double-blind randomized controlled trial. Twenty-seven patients undergoing elective orthopedic surgery under general anesthesia were randomly allocated to one of the following regimes: high dose cannabis (6), low dose cannabis (8), active placebo (6) and placebo (7). The study drugs were administered as premedication 20 minutes before induction of general anesthesia in a double-blind fashion. Cannabis was administered in the form of nabiximols (Sativex®), which is a highly-standardized extract of cannabis plants containing known drug dosages. During the surgery, hemodynamic parameters were monitored, and the anesthesia depth was measured using a BIS monitor, which is based on brain activity analysis. We found a significant effect of treatment groups on bispectral index (BIS) after controlling for minimum alveolar concentration (MAC). The average BIS values, as measured during steady state anesthesia, were significantly higher in the high dose cannabis treatment group. This study provides the first evidence that cannabinoids may affect the BIS. We speculate that the cannabinoid-induced increase in BIS may be the result of changes in EEG activity rather than an indication of a shallower anesthetic state. However, this hypothesis should be examined in further studies. The clinical importance of this study is that with patients who use cannabis adjacent to general anesthesia induction, one cannot rely on the BIS monitoring for the purpose of determining the patient sedative state.

The Hypothalamic-Pituitary-Adrenal Axis and Anesthetics: A Review.

PubMed

Besnier, Emmanuel; Clavier, Thomas; Compere, Vincent

2017-04-01

The hypothalamic-pituitary-adrenal (HPA) axis is essential for human adaptation to stress. However, many anesthetic agents may interfere with the activity of this axis. Although etomidate is known for its suppressive effect on HPA axis function, in vitro evidence suggests that many other drugs used in anesthesia care may also interfere with HPA activity. In this review, we discuss the mechanisms by which all HPA axis activity may be altered during anesthesia and critical care and focus on the impact of hypnotic and analgesic drugs.

The locus coeruleus-norepinephrine network optimizes coupling of cerebral blood volume with oxygen demand.

PubMed

Bekar, Lane K; Wei, Helen S; Nedergaard, Maiken

2012-12-01

Given the brain's uniquely high cell density and tissue oxygen levels bordering on hypoxia, the ability to rapidly and precisely match blood flow to constantly changing patterns in neural activity is an essential feature of cerebrovascular regulation. Locus coeruleus-norepinephrine (LC-NE) projections innervate the cerebral vasculature and can mediate vasoconstriction. However, function of the LC-mediated constriction in blood-flow regulation has never been addressed. Here, using intrinsic optical imaging coupled with an anesthesia regimen that only minimally interferes with LC activity, we show that NE enhances spatial and temporal aspects of functional hyperemia in the mouse somatosensory cortex. Increasing NE levels in the cortex using an α(2)-adrenergic receptor antagonist paradoxically reduces the extent of functional hyperemia while enhancing the surround blood-flow reduction. However, the NE-mediated vasoconstriction optimizes spatial and temporal focusing of the hyperemic response resulting in a sixfold decrease in the disparity between blood volume and oxygen demand. In addition, NE-mediated vasoconstriction accelerated redistribution to subsequently active regions, enhancing temporal synchronization of blood delivery. These observations show an important role for NE in optimizing neurovascular coupling. As LC neuron loss is prominent in Alzheimer and Parkinson diseases, the diminished ability to couple blood volume to oxygen demand may contribute to their pathogenesis.

Genetic Dissection of Aversive Associative Olfactory Learning and Memory in Drosophila Larvae

PubMed Central

Widmann, Annekathrin; Artinger, Marc; Biesinger, Lukas; Boepple, Kathrin; Schlechter, Jana; Selcho, Mareike; Thum, Andreas S.

2016-01-01

Memory formation is a highly complex and dynamic process. It consists of different phases, which depend on various neuronal and molecular mechanisms. In adult Drosophila it was shown that memory formation after aversive Pavlovian conditioning includes—besides other forms—a labile short-term component that consolidates within hours to a longer-lasting memory. Accordingly, memory formation requires the timely controlled action of different neuronal circuits, neurotransmitters, neuromodulators and molecules that were initially identified by classical forward genetic approaches. Compared to adult Drosophila, memory formation was only sporadically analyzed at its larval stage. Here we deconstruct the larval mnemonic organization after aversive olfactory conditioning. We show that after odor-high salt conditioning larvae form two parallel memory phases; a short lasting component that depends on cyclic adenosine 3’5’-monophosphate (cAMP) signaling and synapsin gene function. In addition, we show for the first time for Drosophila larvae an anesthesia resistant component, which relies on radish and bruchpilot gene function, protein kinase C activity, requires presynaptic output of mushroom body Kenyon cells and dopamine function. Given the numerical simplicity of the larval nervous system this work offers a unique prospect for studying memory formation of defined specifications, at full-brain scope with single-cell, and single-synapse resolution. PMID:27768692

Genetic Dissection of Aversive Associative Olfactory Learning and Memory in Drosophila Larvae.

PubMed

Widmann, Annekathrin; Artinger, Marc; Biesinger, Lukas; Boepple, Kathrin; Peters, Christina; Schlechter, Jana; Selcho, Mareike; Thum, Andreas S

2016-10-01

Memory formation is a highly complex and dynamic process. It consists of different phases, which depend on various neuronal and molecular mechanisms. In adult Drosophila it was shown that memory formation after aversive Pavlovian conditioning includes-besides other forms-a labile short-term component that consolidates within hours to a longer-lasting memory. Accordingly, memory formation requires the timely controlled action of different neuronal circuits, neurotransmitters, neuromodulators and molecules that were initially identified by classical forward genetic approaches. Compared to adult Drosophila, memory formation was only sporadically analyzed at its larval stage. Here we deconstruct the larval mnemonic organization after aversive olfactory conditioning. We show that after odor-high salt conditioning larvae form two parallel memory phases; a short lasting component that depends on cyclic adenosine 3'5'-monophosphate (cAMP) signaling and synapsin gene function. In addition, we show for the first time for Drosophila larvae an anesthesia resistant component, which relies on radish and bruchpilot gene function, protein kinase C activity, requires presynaptic output of mushroom body Kenyon cells and dopamine function. Given the numerical simplicity of the larval nervous system this work offers a unique prospect for studying memory formation of defined specifications, at full-brain scope with single-cell, and single-synapse resolution.

Method for image reconstruction of moving radionuclide source distribution

DOEpatents

Stolin, Alexander V.; McKisson, John E.; Lee, Seung Joon; Smith, Mark Frederick

2012-12-18

A method for image reconstruction of moving radionuclide distributions. Its particular embodiment is for single photon emission computed tomography (SPECT) imaging of awake animals, though its techniques are general enough to be applied to other moving radionuclide distributions as well. The invention eliminates motion and blurring artifacts for image reconstructions of moving source distributions. This opens new avenues in the area of small animal brain imaging with radiotracers, which can now be performed without the perturbing influences of anesthesia or physical restraint on the biological system.

Evolution of consciousness: Phylogeny, ontogeny, and emergence from general anesthesia

PubMed Central

Mashour, George A.; Alkire, Michael T.

2013-01-01

Are animals conscious? If so, when did consciousness evolve? We address these long-standing and essential questions using a modern neuroscientific approach that draws on diverse fields such as consciousness studies, evolutionary neurobiology, animal psychology, and anesthesiology. We propose that the stepwise emergence from general anesthesia can serve as a reproducible model to study the evolution of consciousness across various species and use current data from anesthesiology to shed light on the phylogeny of consciousness. Ultimately, we conclude that the neurobiological structure of the vertebrate central nervous system is evolutionarily ancient and highly conserved across species and that the basic neurophysiologic mechanisms supporting consciousness in humans are found at the earliest points of vertebrate brain evolution. Thus, in agreement with Darwin’s insight and the recent “Cambridge Declaration on Consciousness in Non-Human Animals,” a review of modern scientific data suggests that the differences between species in terms of the ability to experience the world is one of degree and not kind. PMID:23754370

Rat model of blood-brain barrier disruption to allow targeted neurovascular therapeutics.

PubMed

Martin, Jacob A; Maris, Alexander S; Ehtesham, Moneeb; Singer, Robert J

2012-11-30

Endothelial cells with tight junctions along with the basement membrane and astrocyte end feet surround cerebral blood vessels to form the blood-brain barrier(1). The barrier selectively excludes molecules from crossing between the blood and the brain based upon their size and charge. This function can impede the delivery of therapeutics for neurological disorders. A number of chemotherapeutic drugs, for example, will not effectively cross the blood-brain barrier to reach tumor cells(2). Thus, improving the delivery of drugs across the blood-brain barrier is an area of interest. The most prevalent methods for enhancing the delivery of drugs to the brain are direct cerebral infusion and blood-brain barrier disruption(3). Direct intracerebral infusion guarantees that therapies reach the brain; however, this method has a limited ability to disperse the drug(4). Blood-brain barrier disruption (BBBD) allows drugs to flow directly from the circulatory system into the brain and thus more effectively reach dispersed tumor cells. Three methods of barrier disruption include osmotic barrier disruption, pharmacological barrier disruption, and focused ultrasound with microbubbles. Osmotic disruption, pioneered by Neuwelt, uses a hypertonic solution of 25% mannitol that dehydrates the cells of the blood-brain barrier causing them to shrink and disrupt their tight junctions. Barrier disruption can also be accomplished pharmacologically with vasoactive compounds such as histamine(5) and bradykinin(6). This method, however, is selective primarily for the brain-tumor barrier(7). Additionally, RMP-7, an analog of the peptide bradykinin, was found to be inferior when compared head-to-head with osmotic BBBD with 25% mannitol(8). Another method, focused ultrasound (FUS) in conjunction with microbubble ultrasound contrast agents, has also been shown to reversibly open the blood-brain barrier(9). In comparison to FUS, though, 25% mannitol has a longer history of safety in human patients that makes it a proven tool for translational research(10-12). In order to accomplish BBBD, mannitol must be delivered at a high rate directly into the brain's arterial circulation. In humans, an endovascular catheter is guided to the brain where rapid, direct flow can be accomplished. This protocol models human BBBD as closely as possible. Following a cut-down to the bifurcation of the common carotid artery, a catheter is inserted retrograde into the ECA and used to deliver mannitol directly into the internal carotid artery (ICA) circulation. Propofol and N2O anesthesia are used for their ability to maximize the effectiveness of barrier disruption(13). If executed properly, this procedure has the ability to safely, effectively, and reversibly open the blood-brain barrier and improve the delivery of drugs that do not ordinarily reach the brain (8,13,14).

Increases in Brain 1H-MR Glutamine and Glutamate Signals Following Acute Exhaustive Endurance Exercise in the Rat

PubMed Central

Świątkiewicz, Maciej; Fiedorowicz, Michał; Orzeł, Jarosław; Wełniak-Kamińska, Marlena; Bogorodzki, Piotr; Langfort, Józef; Grieb, Paweł

2017-01-01

Objective: Proton magnetic resonance spectroscopy (1H-MRS) in ultra-high magnetic field can be used for non-invasive quantitative assessment of brain glutamate (Glu) and glutamine (Gln) in vivo. Glu, the main excitatory neurotransmitter in the central nervous system, is efficiently recycled between synapses and presynaptic terminals through Glu-Gln cycle which involves glutamine synthase confined to astrocytes, and uses 60–80% of energy in the resting human and rat brain. During voluntary or involuntary exercise many brain areas are significantly activated, which certainly intensifies Glu-Gln cycle. However, studies on the effects of exercise on 1H-MRS Glu and/or Gln signals from the brain provided divergent results. The present study on rats was performed to determine changes in 1H-MRS signals from three brain regions engaged in motor activity consequential to forced acute exercise to exhaustion. Method: After habituation to treadmill running, rats were subjected to acute treadmill exercise continued to exhaustion. Each animal participating in the study was subject to two identical imaging sessions performed under light isoflurane anesthesia, prior to, and following the exercise bout. In control experiments, two imaging sessions separated by the period of rest instead of exercise were performed. 1H-NMR spectra were recorded from the cerebellum, striatum, and hippocampus using a 7T small animal MR scanner. Results: Following exhaustive exercise statistically significant increases in the Gln and Glx signals were found in all three locations, whereas increases in the Glu signal were found in the cerebellum and hippocampus. In control experiments, no changes in 1H-MRS signals were found. Conclusion: Increase in glutamine signals from the brain areas engaged in motor activity may reflect a disequilibrium caused by increased turnover in the glutamate-glutamine cycle and a delay in the return of glutamine from astrocytes to neurons. Increased turnover of Glu-Gln cycle may be a result of functional activation caused by forced endurance exercise; the increased rate of ammonia detoxification may also contribute. Increases in glutamate in the cerebellum and hippocampus are suggestive of an anaplerotic increase in glutamate synthesis due to exercise-related stimulation of brain glucose uptake. The disequilibrium in the glutamate-glutamine cycle in brain areas activated during exercise may be a significant contributor to the central fatigue phenomenon. PMID:28197103

Feasibility and pilot study of the Pediatric Anesthesia NeuroDevelopment Assessment (PANDA) project.

PubMed

Sun, Lena S; Li, Guohua; DiMaggio, Charles J; Byrne, Mary W; Ing, Caleb; Miller, Tonya L K; Bellinger, David C; Han, Sena; McGowan, Francis X

2012-10-01

Animal studies have documented that exposure of the developing brain to commonly used anesthetic agents induces neurotoxicity and late abnormal neurobehavioral functions as adults. Results from clinical studies have all been analyzed using existing data sets, and these studies produced inconsistent results. To provide more definitive evidence to address the clinical relevance of anesthetic neurotoxicity in children, an interdisciplinary team of investigators designed and developed the Pediatric Anesthesia NeuroDevelopment Assessment (PANDA) project. We present pilot study results in 28 sibling pairs recruited and tested at the Columbia University Medical Center (CUMC) and Children's Hospital of Boston (CHB) for the PANDA project. The PANDA project uses an ambidirectional cohort design. We performed prospective neuropsychological assessment in 28 exposed-unexposed sibling pairs from 6 to 11 years of age. The exposed siblings were ASA 1 or 2 and had received a single episode of anesthesia for inguinal hernia repair before the age of 36 months and the unexposed siblings had no anesthesia before the age of 36 months. All the sibling pairs were English speaking and were 36 weeks of gestational age or older. Each sibling pair underwent a direct testing using the Wechsler Abbreviated Scale of Intelligence (WASI) and the NEuroPSYchological Assessment, second edition (NEPSY II), and the parents completed questionnaires related to behavior using CBCL and Conners rating. Data are presented as means±SD. We conducted descriptive analyses of the demographic data. We compared both the exposed and the unexposed sibling groups on WASI and NEPSY II, and total and T scores from CBCL and Conners rating were analyzed as continuous data using the paired t test between the two groups. A P<0.05 was considered significant. After the Institutional Review Board approval for the study at both CUMC and CHB, the full PANDA study protocol was implemented to perform a pilot feasibility study. Our success rate was 96.7% in obtaining detailed medical and anesthesia records in our historical cohort. The scores for verbal IQ (exposed=106.1±16.3, unexposed=109.2±17.9), performance IQ (exposed=109.1±16.0, unexposed=113.9±15.9), and full IQ (exposed=108.2±14.0, unexposed=112.8±16.8) were comparable between the siblings. There were no differences between the two groups in T scores for any of the NEPSY II subdomains, CBCL, or Conners rating. An abstraction protocol with web-based electronic data capture forms also was developed in conjunction with the International Center for Health Outcomes and Innovation Research (InCHOIR). The pilot study provided useful information for feasibility to recruit the sample size and to obtain relevant clinical data. For the final study protocol, both the neuropsychological battery and the age range for testing were revised. Our results confirmed the feasibility of our study approach and yielded pilot data from neuropsychological testing.

Two-photon microscopy measurement of cerebral metabolic rate of oxygen using periarteriolar oxygen concentration gradients.

PubMed

Sakadžić, Sava; Yaseen, Mohammad A; Jaswal, Rajeshwer; Roussakis, Emmanuel; Dale, Anders M; Buxton, Richard B; Vinogradov, Sergei A; Boas, David A; Devor, Anna

2016-10-01

The cerebral metabolic rate of oxygen ([Formula: see text]) is an essential parameter for evaluating brain function and pathophysiology. However, the currently available approaches for quantifying [Formula: see text] rely on complex multimodal imaging and mathematical modeling. Here, we introduce a method that allows estimation of [Formula: see text] based on a single measurement modality-two-photon imaging of the partial pressure of oxygen ([Formula: see text]) in cortical tissue. We employed two-photon phosphorescence lifetime microscopy (2PLM) and the oxygen-sensitive nanoprobe PtP-C343 to map the tissue [Formula: see text] distribution around cortical penetrating arterioles. [Formula: see text] is subsequently estimated by fitting the changes of tissue [Formula: see text] around arterioles with the Krogh cylinder model of oxygen diffusion. We measured the baseline [Formula: see text] in anesthetized rats and modulated tissue [Formula: see text] levels by manipulating the depth of anesthesia. This method provides [Formula: see text] measurements localized within [Formula: see text] and it may provide oxygen consumption measurements in individual cortical layers or within confined cortical regions, such as in ischemic penumbra and the foci of functional activation.

Neural correlates of successful semantic processing during propofol sedation.

PubMed

Adapa, Ram M; Davis, Matthew H; Stamatakis, Emmanuel A; Absalom, Anthony R; Menon, David K

2014-07-01

Sedation has a graded effect on brain responses to auditory stimuli: perceptual processing persists at sedation levels that attenuate more complex processing. We used fMRI in healthy volunteers sedated with propofol to assess changes in neural responses to spoken stimuli. Volunteers were scanned awake, sedated, and during recovery, while making perceptual or semantic decisions about nonspeech sounds or spoken words respectively. Sedation caused increased error rates and response times, and differentially affected responses to words in the left inferior frontal gyrus (LIFG) and the left inferior temporal gyrus (LITG). Activity in LIFG regions putatively associated with semantic processing, was significantly reduced by sedation despite sedated volunteers continuing to make accurate semantic decisions. Instead, LITG activity was preserved for words greater than nonspeech sounds and may therefore be associated with persistent semantic processing during the deepest levels of sedation. These results suggest functionally distinct contributions of frontal and temporal regions to semantic decision making. These results have implications for functional imaging studies of language, for understanding mechanisms of impaired speech comprehension in postoperative patients with residual levels of anesthetic, and may contribute to the development of frameworks against which EEG based monitors could be calibrated to detect awareness under anesthesia. Copyright © 2013 Wiley Periodicals, Inc.

Connectivity changes after laser ablation: Resting-state fMRI.

PubMed

Boerwinkle, Varina L; Vedantam, Aditya; Lam, Sandi; Wilfong, Angus A; Curry, Daniel J

2018-05-01

Resting-state functional magnetic resonance imaging (rsfMRI) is emerging as a useful tool in the multimodal assessment of patients with epilepsy. In pediatric patients who cannot perform task-based fMRI, rsfMRI may present an adjunct and alternative. Although changes in brain activation during task-based fMRI have been described after surgery for epilepsy, there is limited data on the role of postoperative rsfMRI. In this short review, we discuss the role of postoperative rsfMRI after laser ablation of seizure foci. By establishing standardized anesthesia protocols and imaging parameters, we have been able to perform serial rsfMRI at postoperative follow-up. The development of in-house software that can merge rsfMRI images to surgical navigation systems has allowed us to enhance the clinical applications of this technique. Resting-state fMRI after laser ablation has the potential to identify changes in connectivity, localize new seizure foci, and guide antiepileptic therapy. In our experience, rsfMRI complements conventional MR imaging and task-based fMRI for the evaluation of patients with seizure recurrence after laser ablation, and represents a potential noninvasive biomarker for functional connectivity. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

[Children's intelligence quotient following general anesthesia for dental care: a clinical observation by Chinese Wechsler young children scale of intelligence].

PubMed

Xia, B; Wang, J H; Xiao, Y M; Liu, K Y; Yang, X D; Ge, L H

2016-04-18

It has been demonstrated that anesthetics exposure may lead to neurocognitive impairment in developing brain of animal models. However, for the limitation that the animal models cannot fully mimic the dose and duration in clinical settings especially for dental general anesthesia, the clinical significance of anesthetics exposure on developing central nervous system remains undetermined. Therefore, we conducted the current study in order to observe the fluctuation of intelligence quotient (IQ) after the administration of dental general anesthesia comparing to that before surgery. We conducted the current study in order to observe the fluctuation of intelligence quotient (IQ) after the administration of dental general anesthesia compared with that before surgery. Thirty two patients, ASA I, who were exposed to dental general anesthesia in Department of Pediatric Dentistry Peking University School and Hospital of Stomatology, aged 4 to 6.5 years, were enrolled in this prospective study. Patients with severe learning difficulties or communication disorders were excluded. Written and informed consent was obtained from each patients' family which was fully explained of the purpose and method of study. Their intelligence quotients were evaluated with the Chinese Wechsler young children scale of intelligence (Urban version) before and 2 weeks after dental anesthesia. They were treated by experienced pediatric dentists and the sevoflurane, propofol and nitrous oxide were used for general anesthesia by anesthetist. Articaine hydrochloride and epinephrine tartrate injections were used for their pulp treatment or extraction. The examiners and scorers for IQ had technical training in the test administration. All the patients were tested by the same examiner and with standardized guide language. Each subtest was scored according to the tool review. Verbal IQ and performance IQ consisted of relevant 5 subtests and full scale IQ. Statistical analyses were performed by SPSS 18.0. All the scores of subtests and 3 types of IQ were expressed as mean±standard deviation. Paired two-tailed t test was applied and P<0.05 was accepted as statistically significant. The results of intelligent assessment from 28 subjects were collected. The anesthetic time was (163.4±32.6) min and the number of treated teeth was 12.1±2.3, mean age (4.60±0.41) years; age range=4.04 to 5.44 years. Among the patients, there were 13 girls and 15 boys. There was no significant difference in gender distribution. The postoperative full IQ (128.46±10.85) was higher than that before surgery (124.64±11.46, P= 0.017). We found that the elevation of performance IQ, to a large extent, contributed to this change in full IQ (P= 0.007). Correspondingly, there was no statistical difference in the verbal IQ, which was 119.68±11.74 to 120.21±15.61 (P=0.854). Dental general anesthesia has no negative effect on the intelligence of preschool children, who were treated under general anesthesia by sevoflurane, propofol and nitrous oxide for 2 to 4 hours. The full IQ and performance IQ were slightly enhanced after treatment which can be explained by the memory effect.

The influence of propofol anesthesia exposure on nonaversive memory retrieval and expression of molecules involved in memory process in the dorsal hippocampus in peripubertal rats.

PubMed

Pavković, Željko; Milanović, Desanka; Ruždijić, Sabera; Kanazir, Selma; Pešić, Vesna

2018-06-01

The effects of anesthetic drugs on postoperative cognitive function in children are not well defined and have not been experimentally addressed. The present study aimed to examine the influence of propofol anesthesia exposure on nonaversive hippocampus-dependent learning and biochemical changes involved in memory process in the dorsal hippocampus, in peripubertal rats as the rodent model of periadolescence. The intersession spatial habituation and the novel object recognition tasks were used to assess spatial and nonspatial, nonaversive hippocampus-dependent learning. The exposure to anesthesia was performed after comparably long acquisition phases in both tasks. Behavioral testing lasted for 2 consecutive days (24-hour retention period). Changes in the expression of molecules involved in memory retrieval/reconsolidation were examined in the dorsal hippocampus by Western blot and immunohistochemistry, at the time of behavioral testing. Exposure to propofol anesthesia resulted in inappropriate assessment of spatial novelty at the beginning of the test session and affected continuation of acquisition in the spatial habituation test. The treatment did not affect recognition of the novel object at the beginning of the test session but it attenuated overall preference to novelty, reflecting retrieval of a weak memory. The expression of phosphorylated extracellular signal-regulated kinase 2 (involved in memory retrieval) was decreased while the level of phosphorylated Ca 2+ /calmodulin-dependent protein kinase IIα and early growth response protein 1 (involved in memory reconsolidation) was increased in the dorsal hippocampus. The level of Finkel-Biskis-Jinkins murine osteosarcoma viral oncogene homolog B (neuronal activity indicator) was increased in the dorsal dentate gyrus. Enhanced exploratory activity was still evident in the propofol anesthesia exposure (PAE) group 48 hour after the treatment in both tasks. In peripubertal rats, propofol anesthesia exposure affects memory retrieval and acquisition of new learning in the spatial and nonspatial, nonaversive learning tasks 24 hour after the treatment, along with the expression of molecules that participate in memory retrieval/reconsolidation in the dorsal hippocampus. These results may have clinical implications, favoring control of basic cognitive functions in older children after the propofol exposure. © 2018 John Wiley & Sons Ltd.

In Vivo Recording of Neural and Behavioral Correlates of Anesthesia Induction, Reversal, and Euthanasia in Cephalopod Molluscs.

PubMed

Butler-Struben, Hanna M; Brophy, Samantha M; Johnson, Nasira A; Crook, Robyn J

2018-01-01

Cephalopod molluscs are among the most behaviorally and neurologically complex invertebrates. As they are now included in research animal welfare regulations in many countries, humane and effective anesthesia is required during invasive procedures. However, currently there is no evidence that agents believed to act as anesthetics produce effects beyond immobility. In this study we demonstrate, for the first time, that two of the most commonly used agents in cephalopod general anesthesia, magnesium chloride and ethanol, are capable of producing strong and reversible blockade of afferent and efferent neural signal; thus they are genuine anesthetics, rather than simply sedating agents that render animals immobile but not insensible. Additionally, we demonstrate that injected magnesium chloride and lidocaine are effective local anesthetic agents. This represents a considerable advance for cephalopod welfare. Using a reversible, minimally invasive recording procedure, we measured activity in the pallial nerve of cuttlefish ( Sepia bandensis ) and octopus ( Abdopus aculeatus, Octopus bocki ), during induction and reversal for five putative general anesthetic and two local anesthetic agents. We describe the temporal relationship between loss of behavioral responses (immobility), loss of efferent neural signal (loss of "consciousness") and loss of afferent neural signal (anesthesia) for general anesthesia, and loss of afferent signal for local anesthesia. Both ethanol and magnesium chloride were effective as bath-applied general anesthetics, causing immobility, complete loss of behavioral responsiveness and complete loss of afferent and efferent neural signal. Cold seawater, diethyl ether, and MS-222 (tricaine) were ineffective. Subcutaneous injection of either lidocaine or magnesium chloride blocked behavioral and neural responses to pinch in the injected area, and we conclude that both are effective local anesthetic agents for cephalopods. Lastly, we demonstrate that a standard euthanasia protocol-immersion in isotonic magnesium chloride followed by surgical decerebration-produced no behavioral response and no neural activity during surgical euthanasia. Based on these data, we conclude that both magnesium chloride and ethanol can function as general anesthetic agents, and lidocaine and magnesium chloride can function as local anesthetic agents for cephalopod molluscs.

In Vivo Recording of Neural and Behavioral Correlates of Anesthesia Induction, Reversal, and Euthanasia in Cephalopod Molluscs

PubMed Central

Butler-Struben, Hanna M.; Brophy, Samantha M.; Johnson, Nasira A.; Crook, Robyn J.

2018-01-01

Cephalopod molluscs are among the most behaviorally and neurologically complex invertebrates. As they are now included in research animal welfare regulations in many countries, humane and effective anesthesia is required during invasive procedures. However, currently there is no evidence that agents believed to act as anesthetics produce effects beyond immobility. In this study we demonstrate, for the first time, that two of the most commonly used agents in cephalopod general anesthesia, magnesium chloride and ethanol, are capable of producing strong and reversible blockade of afferent and efferent neural signal; thus they are genuine anesthetics, rather than simply sedating agents that render animals immobile but not insensible. Additionally, we demonstrate that injected magnesium chloride and lidocaine are effective local anesthetic agents. This represents a considerable advance for cephalopod welfare. Using a reversible, minimally invasive recording procedure, we measured activity in the pallial nerve of cuttlefish (Sepia bandensis) and octopus (Abdopus aculeatus, Octopus bocki), during induction and reversal for five putative general anesthetic and two local anesthetic agents. We describe the temporal relationship between loss of behavioral responses (immobility), loss of efferent neural signal (loss of “consciousness”) and loss of afferent neural signal (anesthesia) for general anesthesia, and loss of afferent signal for local anesthesia. Both ethanol and magnesium chloride were effective as bath-applied general anesthetics, causing immobility, complete loss of behavioral responsiveness and complete loss of afferent and efferent neural signal. Cold seawater, diethyl ether, and MS-222 (tricaine) were ineffective. Subcutaneous injection of either lidocaine or magnesium chloride blocked behavioral and neural responses to pinch in the injected area, and we conclude that both are effective local anesthetic agents for cephalopods. Lastly, we demonstrate that a standard euthanasia protocol—immersion in isotonic magnesium chloride followed by surgical decerebration—produced no behavioral response and no neural activity during surgical euthanasia. Based on these data, we conclude that both magnesium chloride and ethanol can function as general anesthetic agents, and lidocaine and magnesium chloride can function as local anesthetic agents for cephalopod molluscs. PMID:29515454

Hemodynamic responses to etomidate versus ketamine-thiopental sodium combination for anesthetic induction in coronary artery bypass graft surgery patients with low ejection fraction: a double-blind, randomized, clinical trial.

PubMed

Habibi, Mohammad Reza; Baradari, Afshin Gholipour; Soleimani, Aria; Emami Zeydi, Amir; Nia, Hamid Sharif; Habibi, Ali; Onagh, Naser

2014-10-01

During induction of anesthesia and intubation, hemodynamic changes are very important; especially in patients with coronary artery disease (CAD) and left ventricular dysfunction. A little information is available on the hemodynamic effects of a combination of ketamine-thiopental for induction of anesthesia in patients undergoing coronary artery bypass graft (CABG) surgery, with impaired ventricular function. The aim of this study was to compare the hemodynamic responses to etomidate versus ketamine-thiopental sodium combination for anesthetic induction in CABG surgery patients with low ejection fraction (EF<45%). In a double blind randomized clinical trial, a total of 100 patients, scheduled for elective CABG surgery were randomly assigned into two groups. These patients received either etomidate or ketamine-thiopental sodium combination at induction of anesthesia. Hemodynamics variable were measured and recorded at baseline, immediately before and after laryngoscopy and intubation, one, two and three minutes after intubation. Also, muscle twitching incidence among patients in two groups was evaluated. No significant differences between the two groups regarding the changes of hemodynamic variables including systolic and diastolic arterial blood pressure, mean arterial pressure and heart rate, were notice (p>0.05). Muscle twitching was not observed in the two groups. Hemodynamic stability after administration of ketamine-thiopental sodium combination for induction of anesthesia in patients undergoing CABG surgery, with impaired ventricular function, supports the clinical impression that this combination is safe in CABG surgery patients with low EF.

Determination of Serotonin and Dopamine Metabolites in Human Brain Microdialysis and Cerebrospinal Fluid Samples by UPLC-MS/MS: Discovery of Intact Glucuronide and Sulfate Conjugates

PubMed Central

Suominen, Tina; Uutela, Päivi; Ketola, Raimo A.; Bergquist, Jonas; Hillered, Lars; Finel, Moshe; Zhang, Hongbo; Laakso, Aki; Kostiainen, Risto

2013-01-01

An UPLC-MS/MS method was developed for the determination of serotonin (5-HT), dopamine (DA), their phase I metabolites 5-HIAA, DOPAC and HVA, and their sulfate and glucuronide conjugates in human brain microdialysis samples obtained from two patients with acute brain injuries, ventricular cerebrospinal fluid (CSF) samples obtained from four patients with obstructive hydrocephalus, and a lumbar CSF sample pooled mainly from patients undergoing spinal anesthesia in preparation for orthopedic surgery. The method was validated by determining the limits of detection and quantification, linearity, repeatability and specificity. The direct method enabled the analysis of the intact phase II metabolites of 5-HT and DA, without hydrolysis of the conjugates. The method also enabled the analysis of the regioisomers of the conjugates, and several intact glucuronide and sulfate conjugates were identified and quantified for the first time in the human brain microdialysis and CSF samples. We were able to show the presence of 5-HIAA sulfate, and that dopamine-3-O-sulfate predominates over dopamine-4-O-sulfate in the human brain. The quantitative results suggest that sulfonation is a more important phase II metabolism pathway than glucuronidation in the human brain. PMID:23826355

Blood-brain barrier alteration after microwave-induced hyperthermia is purely a thermal effect: I. Temperature and power measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moriyama, E.; Salcman, M.; Broadwell, R.D.

The effect of microwave-induced hyperthermia on the blood-brain barrier was studied in 21 Sprague-Dawley rats. Under sodium pentobarbital anesthesia, animals were place in a stereotactic frame, and an interstitial microwave antenna operating at 2450 MHz was inserted in a bony groove drilled parallel to the sagittal suture. Some antennae were equipped with an external cooling jacket. Temperature measurements were made lateral to the antenna by fluoroptical thermometry, and power was calculated from the time-temperature profile. Five minutes prior to termination of microwave irradiation, horseradish peroxidase (1 mg/20 g body weight) was injected intravenously. Extravasation of horseradish peroxidase was observed inmore » brain tissue heated above 44.3 degrees C for 30 minutes and at 42.5 degrees C for 60 minutes. Microwave irradiation failed to open the blood-brain barrier when brain temperatures were sustained below 40.3 degrees C by the cooling system. Extravasation of blood-borne peroxidase occurred at sites of maximal temperature elevation, even when these did not coincide with the site of maximum power density. The data suggest that microwave-induced hyperthermia is an effective means for opening the blood-brain barrier and that the mechanism is not related to the nonthermal effect of microwaves.« less

Comparison of the cardiopulmonary effects of anesthesia maintained by continuous infusion of romifidine, guaifenesin, and ketamine with anesthesia maintained by inhalation of halothane in horses.

PubMed

McMurphy, Rose M; Young, Lesley E; Marlin, David J; Walsh, Karen

2002-12-01

To compare cardiopulmonary responses during anesthesia maintained with halothane and responses during anesthesia maintained by use of a total intravenous anesthetic (TIVA) regimen in horses. 7 healthy adult horses (1 female, 6 geldings). Each horse was anesthetized twice. Romifidine was administered IV, and anesthesia was induced by IV administration of ketamine. Anesthesia was maintained for 75 minutes by administration of halothane (HA) or IV infusion of romifidine, guaifenesin, and ketamine (TIVA). The order for TIVA or HA was randomized. Cardiopulmonary variables were measured 40, 60, and 75 minutes after the start of HA orTIVA. Systolic, diastolic, and mean carotid arterial pressures, velocity time integral, and peak acceleration of aortic blood flow were greater, and systolic, diastolic, and mean pulmonary arterial pressure were lower at all time points for TIVA than for HA. Pre-ejection period was shorter and ejection time was longer for TIVA than for HA. Heart rate was greater for HA at 60 minutes. Minute ventilation and alveolar ventilation were greater and inspiratory time was longer for TIVA than for HA at 75 minutes. The PaCO2 was higher at 60 and 75 minutes for HA than forTIVA. Horses receiving a constant-rate infusion of romifidine, guaifenesin, and ketamine maintained higher arterial blood pressures than when they were administered HA. There was some indication that left ventricular function may be better during TIVA, but influences of preload and afterload on measured variables could account for some of these differences.

The effect of electroacupuncture on postoperative immunoinflammatory response in patients undergoing supratentorial craniotomy

PubMed Central

LI, GUOYAN; LI, SHUQIN; WANG, BAOGUO; AN, LIXIN

2013-01-01

The aim of this study was to explore the effect of electroacupuncture (EA) on immune function in patients undergoing supratentorial craniotomy. We also examined whether point specificity in EA was present. The study involved 29 patients undergoing craniotomy. The patients were divided into three groups: a control (C, n=10), an EA (A, n=9) and a sham acupoints group (S, n=10). Blood samples were collected at the following time points: before anesthesia (T0), 4 h after the induction of anesthesia (T1), 1 day post-surgery (T2) and 2 days post-surgery (T3) to determine the levels of tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8), interleukin-10 (IL-10), immunoglobulin M (IgM), IgA and IgG. Data were analyzed using SPSS 13.0 software. When comparing the levels of cytokines following surgery, we observed that the peripheral blood IL-8 levels in groups A and S were increased significantly compared with those of group C at 1 and 2 days after surgery. When comparing immunoglobulin levels after surgery, we established that the peripheral blood IgA levels in group C had decreased significantly compared to those of group A and group S 4 h after induction of anesthesia and 1 day after surgery. However, there was no significant difference between group A and group S. Compared with simple general anesthesia, acupuncture combined with anesthesia partially reduces immune suppression in the perioperative periods under the same conditions as the simple general anesthesia. Point specificity in EA was not present. PMID:24137250

Study of the development of fetal baboon brain using magnetic resonance imaging at 3 Tesla

PubMed Central

Liu, Feng; Garland, Marianne; Duan, Yunsuo; Stark, Raymond I.; Xu, Dongrong; Dong, Zhengchao; Bansal, Ravi; Peterson, Bradley S.; Kangarlu, Alayar

2008-01-01

Direct observational data on the development of the brains of human and nonhuman primates is on remarkably scant, and most of our understanding of primate brain development is extrapolated from findings in rodent models. Magnetic resonance imaging (MRI) is a promising tool for the noninvasive, longitudinal study of the developing primate brain. We devised a protocol to scan pregnant baboons serially at 3 T for up to 3 h per session. Seven baboons were scanned 1–6 times, beginning as early as 56 days post-conceptional age, and as late as 185 days (term ~185 days). Successful scanning of the fetal baboon required careful animal preparation and anesthesia, in addition to optimization of the scanning protocol. We successfully acquired maps of relaxation times (T1 and T2) and high-resolution anatomical images of the brains of fetal baboons at multiple time points during the course of gestation. These images demonstrated the convergence of gray and white matter contrast near term, and furthermore demonstrated that the loss of contrast at that age is a consequence of the continuous change in relaxation times during fetal brain development. These data furthermore demonstrate that maps of relaxation times have clear advantages over the relaxation time weighted images for the tracking of the changes in brain structure during fetal development. This protocol for in utero MRI of fetal baboon brains will help to advance the use of nonhuman primate models to study fetal brain development longitudinally. PMID:18155925

Deep-brain stimulation for aggressive and disruptive behavior.

PubMed

Franzini, Angelo; Broggi, Giovanni; Cordella, Roberto; Dones, Ivano; Messina, Giuseppe

2013-01-01

To describe our institutional experience with deep-brain stimulation (DBS) used in the treatment of aggressive and disruptive behavior refractory to conservative treatment. With stereotactic methodology and under general anesthesia, seven patients (from 2002 to 2010) were given DBS in the posterior hypothalamic region, bilaterally, and with the aid of intraoperative microrecording. Six of seven patients presented a clear reduction in the aggression and disruptive bouts, with subsequent simplification of familiar management. DBS of the posterior hypothalamic region could be an effective treatment for patients affected by mental retardation in whom disruptive and drug-refractory aggressive behavior coexists. Although several experimental data are available on this target, further studies are necessary to confirm the long-term efficacy and safety of this procedure. Copyright © 2013. Published by Elsevier Inc.

Mechanistic Insights into Neurotoxicity Induced by Anesthetics in the Developing Brain

PubMed Central

Lei, Xi; Guo, Qihao; Zhang, Jun

2012-01-01

Compelling evidence has shown that exposure to anesthetics used in the clinic can cause neurodegeneration in the mammalian developing brain, but the basis of this is not clear. Neurotoxicity induced by exposure to anesthestics in early life involves neuroapoptosis and impairment of neurodevelopmental processes such as neurogenesis, synaptogenesis and immature glial development. These effects may subsequently contribute to behavior abnormalities in later life. In this paper, we reviewed the possible mechanisms of anesthetic-induced neurotoxicity based on new in vitro and in vivo findings. Also, we discussed ways to protect against anesthetic-induced neurotoxicity and their implications for exploring cellular and molecular mechanisms of neuroprotection. These findings help in improving our understanding of developmental neurotoxicology and in avoiding adverse neurological outcomes in anesthesia practice. PMID:22837663

A comparison of different synchronization measures in electroencephalogram during propofol anesthesia.

PubMed

Liang, Zhenhu; Ren, Ye; Yan, Jiaqing; Li, Duan; Voss, Logan J; Sleigh, Jamie W; Li, Xiaoli

2016-08-01

Electroencephalogram (EEG) synchronization is becoming an essential tool to describe neurophysiological mechanisms of communication between brain regions under general anesthesia. Different synchronization measures have their own properties to reflect the changes of EEG activities during different anesthetic states. However, the performance characteristics and the relations of different synchronization measures in evaluating synchronization changes during propofol-induced anesthesia are not fully elucidated. Two-channel EEG data from seven volunteers who had undergone a brief standardized propofol anesthesia were then adopted to calculate eight synchronization indexes. We computed the prediction probability (P K ) of synchronization indexes with Bispectral Index (BIS) and propofol effect-site concentration (C eff ) to quantify the ability of the indexes to predict BIS and C eff . Also, box plots and coefficient of variation were used to reflect the different synchronization changes and their robustness to noise in awake, unconscious and recovery states, and the Pearson correlation coefficient (R) was used for assessing the relationship among synchronization measures, BIS and C eff . Permutation cross mutual information (PCMI) and determinism (DET) could predict BIS and follow C eff better than nonlinear interdependence (NI), mutual information based on kernel estimation (KerMI) and cross correlation. Wavelet transform coherence (WTC) in α and β frequency bands followed BIS and C eff better than that in other frequency bands. There was a significant decrease in unconscious state and a significant increase in recovery state for PCMI and NI, while the trends were opposite for KerMI, DET and WTC. Phase synchronization based on phase locking value (PSPLV) in δ, θ, α and γ1 frequency bands dropped significantly in unconscious state, whereas it had no significant synchronization in recovery state. Moreover, PCMI, NI, DET correlated closely with each other and they had a better robustness to noise and higher correlation with BIS and C eff than other synchronization indexes. Propofol caused EEG synchronization changes during the anesthetic period. Different synchronization measures had individual properties in evaluating synchronization changes in different anesthetic states, which might be related to various forms of neural activities and neurophysiological mechanisms under general anesthesia.

The effect of perioperative insulin treatment on cardiodepression in mild adiposity in mice.

PubMed

Boly, Chantal A; Eringa, Etto C; Bouwman, R Arthur; van den Akker, Rob F P; de Man, Frances S; Schalij, Ingrid; Loer, Stephan A; Boer, Christa; van den Brom, Charissa E

2016-09-20

While most studies focus on cardiovascular morbidity following anesthesia and surgery in excessive obesity, it is unknown whether these intraoperative cardiovascular alterations also occur in milder forms of adiposity without type 2 diabetes and if insulin is a possible treatment to improve intraoperative myocardial performance. In this experimental study we investigated whether mild adiposity without metabolic alterations is already associated with cardiometabolic dysfunction during anesthesia, mechanical ventilation and surgery and whether these myocardial alterations can be neutralized by intraoperative insulin treatment. Mice were fed a western (WD) or control diet (CD) for 4 weeks. After metabolic profiling, mice underwent general anesthesia, mechanical ventilation and surgery. Cardiac function was determined with echocardiography and left-ventricular pressure-volume analysis. Myocardial perfusion was determined with contrast-enhanced echocardiography. WD-fed mice were subsequently treated with insulin by hyperinsulinemic euglycemic clamping followed by the same measurements of cardiac function and perfusion. Western-type diet feeding led to a 13 % increase in bodyweight, (p < 0.0001) and increased adipose tissue mass, without metabolic alterations. Despite this mild phenotype, WD-fed mice had decreased systolic and diastolic function (end-systolic elastance was 2.0 ± 0.5 versus 4.1 ± 2.4 mmHg/μL, p = 0.01 and diastolic beta was 0.07 ± 0.03 versus 0.04 ± 0.01 mmHg/μL, p = 0.02) compared to CD-fed mice. Ventriculo-arterial coupling and myocardial perfusion were decreased by 48 % (p = 0.003) and 43 % (p = 0.03) respectively. Insulin treatment in WD-fed mice improved echo-derived systolic function (fractional shortening 42 ± 5 % to 46 ± 3, p = 0.05), likely due to decreased afterload, but there was no effect on load-independent measures of systolic function or myocardial perfusion. However, there was a trend towards improved diastolic function after insulin treatment (43 % improvement, p = 0.05) in WD-fed mice. Mild adiposity without metabolic alterations already affected cardiac function and perfusion during anesthesia, mechanical ventilation and surgery in mice. Intraoperative insulin may be beneficial to reduce afterload and enhance intraoperative ventricular relaxation, but not to improve ventricular contractility or myocardial perfusion.

Critical appraisal of organ procurement under Maastricht 3 condition.

PubMed

Puybasset, L; Bazin, J-E; Beloucif, S; Bizouarn, P; Crozier, S; Devalois, B; Eon, B; Fieux, F; Gisquet, E; Guibet-Lafaye, C; Kentish, N; Lienhart, A; Nicolas-Robin, A; Otero Lopez, M; Pelluchon, C; Roussin, F; Beydon, L

2014-02-01

The ethics committee of the French Society of Anesthesia and Intensive Care (Sfar) has been requested by the French Biomedical Agency to consider the issue of organ donation in patients after the decision to withdraw life-supportive therapies has been taken. This type of organ donation is performed in the USA, Canada, the United Kingdom, the Netherlands and Belgium. The three former countries have published recommendations formalizing procedures and operations. The French Society of Anesthesia and Intensive Care (Société française d'anesthésie et de reanimation [Sfar]) ethics committee has considered this issue and envisioned the different aspects of the whole process. Consequently, it sounded a note of caution regarding the applicability of this type of organ procurement in unselected patients following a decision to withdraw life-supportive therapies. According to French regulations concerning organ procurement in brain-dead patients, the committee stresses the need to restrict this specific way of procurement to severely brain-injured patients, once confirmatory investigations predicting a catastrophic prognosis have been performed. This suggests that the nature of the confirmatory investigation required should be formalized by the French Biomedical Agency on behalf of the French parliamentarians, which should help preserve population trust regarding organ procurement and provide a framework for medical decision. This text has been endorsed by the Sfar. Copyright © 2013 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

Randomized controlled trial of moderate hypothermia versus deep hypothermia anesthesia on brain injury during Stanford A aortic dissection surgery.

PubMed

Sun, Xufang; Yang, Hua; Li, Xinyu; Wang, Yue; Zhang, Chuncheng; Song, Zhimin; Pan, Zhenxiang

2018-01-01

This study aimed to compare the effects of moderate versus deep hypothermia anesthesia for Stanford A aortic dissection surgery on brain injury. A total of 82 patients who would undergo Stanford A aortic dissection surgery were randomized into two groups: moderate hypothermia group (MH, n = 40, nasopharyngeal temperature 25 °C, and rectal temperature 28 °C) and deep hypothermia group (DH, n = 42, nasopharyngeal temperature 20 °C, and rectal temperature 25 °C). Different vascular replacement techniques including aortic root replacement, Bentall, and Wheat were used. The intraoperative and postoperative indicators of these patients were recorded. There were no differences in intraoperative and postoperative measures between MH and DH groups. The concentrations of neuron-specific enolase and S-100β increased with operation time, and were significantly lower in MH group than those in the DH group (P < 0.05). The occurrence rates of complications including chenosis, postoperative agitation, and neurological complications in MH group were significantly lower than in DH group. The recovery time, postoperative tube, and ICU intubation stay were significantly shorter in MH group than those in DH group (P < 0.05). There were no significant differences revealed in hospital stay and death rate. MH exhibited better cerebral protective effects, less complications, and shorter tube time than DH in surgery for Stanford A aortic dissection.

High-resolution detection of 13C multiplets from the conscious mouse brain by ex vivo NMR spectroscopy

PubMed Central

Marin-Valencia, Isaac; Good, Levi B.; Ma, Qian; Jeffrey, F. Mark; Malloy, Craig R.; Pascual, Juan M.

2011-01-01

Glucose readily supplies the brain with the majority of carbon needed to sustain neurotransmitter production and utilization., The rate of brain glucose metabolism can be computed using 13C nuclear magnetic resonance (NMR) spectroscopy by detecting changes in 13C contents of products generated by cerebral metabolism. As previously observed, scalar coupling between adjacent 13C carbons (multiplets) can provide additional information to 13C contents for the computation of metabolic rates. Most NMR studies have been conducted in large animals (often under anesthesia) because the mass of the target organ is a limiting factor for NMR. Yet, despite the challengingly small size of the mouse brain, NMR studies are highly desirable because the mouse constitutes a common animal model for human neurological disorders. We have developed a method for the ex vivo resolution of NMR multiplets arising from the brain of an awake mouse after the infusion of [1,6-13C2]glucose. NMR spectra obtained by this method display favorable signal-to-noise ratios. With this protocol, the 13C multiplets of glutamate, glutamine, GABA and aspartate achieved steady state after 150 min. The method enables the accurate resolution of multiplets over time in the awake mouse brain. We anticipate that this method can be broadly applicable to compute brain fluxes in normal and transgenic mouse models of neurological disorders. PMID:21946227

The effect of general and spinal anesthesia on balance control in elderly patients.

PubMed

Suárez, Alejo; Macadar, Omar

2008-01-01

Falls are a major problem in the elderly population, but few communications address the influence of anesthesia on balance control. This study reports how a general balanced anesthesia (GBA) and a spinal anesthesia (SA) affect balance control in the elderly. We divided into three groups, according to electronystagmography findings and type of anesthesia, 21 men older than 65 years (mean age, 72 years) who were scheduled for prostate adenectomy. One group, designated GBN, consisted of normal subjects who underwent surgery under GBA. In another group, designated GBP, were pathological subjects who had clinically compensated central vestibular disorders (CVDs) and underwent surgery under GBA. The third group, designated SP, contained CVD patients who underwent surgery under SA. We assessed balance control via static posturography preoperatively and 48 hours postoperatively. We observed no change in balance control parameters (center of pressure distribution area [COPa] or COP sway velocity [SV]) for those patients in the GBN group or for those in the SP group. We did observe a significant difference for the patients in the GBP group, with higher postoperative values of COPa and SV (Wilcoxon signed rank test). Our results showed that in subjects with clinically compensated underlying CVD prior to a GBA, balance control worsens after the procedure, whereas no change in balance control occurs after an SA. Balance control in subjects with normal vestibuloocular function did not change even after a GBA.

Survey of the sevoflurane sedation status in one provincial dental clinic center for the disabled

PubMed Central

Park, Chang-hyun

2016-01-01

Background Sevoflurane sedation in pediatric and disabled patients has the advantage of faster induction and recovery compared to general anesthesia, as well as minimum influence on the respiratory and cardiovascular functions, and airway protective reflexes. This study aimed to evaluate the clinical efficacy of sevoflurane sedation used in dental treatment at one provincial dental clinic center for the disabled. Methods We investigated patients' gender, age, reasons for undergoing sedation, medication history prior to treatment, duration of anesthesia, treatment length, type of treatment, and yearly patterns, for 387 cases of dental treatment performed using sevoflurane sedation from January 2013 to October 2016. Results We analyzed 387 cases (215 male patients, 172 female patients). Male patients aged 20 year or older accounted for 39.0% of all patients, marking the highest proportion. Patient's lack of cooperation was the most common reason for performing dental sedation. Prosthetic treatment was the most frequently practiced, accounting for 174 treatment cases. The mean lengths of the entire treatment and of the dental procedure were 55.2 min and 39.8 min, respectively. Conclusions Sevoflurane sedation has the advantage of fast anesthesia induction and recovery compared to general anesthesia; therefore, it can be used efficiently to induce anesthesia in pediatric and disabled patients during short dental procedures, enabling stable treatment of these patients. PMID:28879316

Effect of Anesthesia Carrier Gas on In-Vivo Circulation Times of Ultrasound Microbubble Contrast Agents in Rats

PubMed Central

Mullin, Lee; Gessner, Ryan; Kwan, James; Kaya, Mehmet; Borden, Mark A.; Dayton, Paul A.

2012-01-01

Purpose Microbubble contrast agents are currently implemented in a variety of both clinical and preclinical ultrasound imaging studies. The therapeutic and diagnostic capabilities of these contrast agents are limited by their short in-vivo lifetimes, and research to lengthen their circulation times is ongoing. In this manuscript, observations are presented from a controlled experiment performed to evaluate differences in circulation times for lipid shelled perfluorocarbon-filled contrast agents circulating within rodents as a function of inhaled anesthesia carrier gas. Methods The effects of two common anesthesia carrier gas selections - pure oxygen and medical air – were observed within five rats. Contrast agent persistence within the kidney was measured and compared for oxygen and air anesthesia carrier gas for six bolus contrast injections in each animal. Simulations were performed to examine microbubble behavior with changes in external environment gases. Results A statistically significant extension of contrast circulation time was observed for animals breathing medical air compared to breathing pure oxygen. Simulations support experimental observations and indicate that enhanced contrast persistence may be explained by reduced ventilation/perfusion mismatch and classical diffusion, in which nitrogen plays a key role by contributing to the volume and diluting other gas species in the microbubble gas core. Conclusion: Using medical air in place of oxygen as the carrier gas for isoflurane anesthesia can increase the circulation lifetime of ultrasound microbubble contrast agents. PMID:21246710

Biothermal Model of Patient for Brain Hypothermia Treatment

NASA Astrophysics Data System (ADS)

Wakamatsu, Hidetoshi; Gaohua, Lu

A biothermal model of patient is proposed and verified for the brain hypothermia treatment, since the conventionally applied biothermal models are inappropriate for their unprecedented application. The model is constructed on the basis of the clinical practice of the pertinent therapy and characterized by the mathematical relation with variable ambient temperatures, in consideration of the clinical treatments such as the vital cardiopulmonary regulation. It has geometrically clear representation of multi-segmental core-shell structure, database of physiological and physical parameters with a systemic state equation setting the initial temperature of each compartment. Its step response gives the time constant about 3 hours in agreement with clinical knowledge. As for the essential property of the model, the dynamic temperature of its face-core compartment is realized, which corresponds to the tympanic membrane temperature measured under the practical anesthesia. From the various simulations consistent with the phenomena of clinical practice, it is concluded that the proposed model is appropriate for the theoretical analysis and clinical application to the brain hypothermia treatment.

Biomedical application of wavelets: analysis of electroencephalograph signals for monitoring depth of anesthesia

NASA Astrophysics Data System (ADS)

Abbate, Agostino; Nayak, A.; Koay, J.; Roy, R. J.; Das, Pankaj K.

1996-03-01

The wavelet transform (WT) has been used to study the nonstationary information in the electroencephalograph (EEG) as an aid in determining the anesthetic depth. A complex analytic mother wavelet is utilized to obtain the time evolution of the various spectral components of the EEG signal. The technique is utilized for the detection and spectral analysis of transient and background processes in the awake and asleep states. It can be observed that the response of both states before the application of the stimulus is similar in amplitude but not in spectral contents, which suggests a background activity of the brain. The brain reacts to the external stimulus in two different modes depending on the state of consciousness of the subject. In the case of awake state, there is an evident increase in response, while for the sleep state a reduction in this activity is observed. This analysis seems to suggest that the brain has an ongoing background process that monitors external stimulus in both the sleep and awake states.

Early postnatal exposure to isoflurane causes cognitive deficits and disrupts development of newborn hippocampal neurons via activation of the mTOR pathway

PubMed Central

Lim, Sanghee; Kwak, Minhye; Gray, Christy D.; Xu, Michael; Choi, Jun H.; Junn, Sue; Kim, Jieun; Xu, Jing; Schaefer, Michele; Johns, Roger A.; Song, Hongjun; Ming, Guo-Li; Mintz, C. David

2017-01-01

Clinical and preclinical studies indicate that early postnatal exposure to anesthetics can lead to lasting deficits in learning and other cognitive processes. The mechanism underlying this phenomenon has not been clarified and there is no treatment currently available. Recent evidence suggests that anesthetics might cause persistent deficits in cognitive function by disrupting key events in brain development. The hippocampus, a brain region that is critical for learning and memory, contains a large number of neurons that develop in the early postnatal period, which are thus vulnerable to perturbation by anesthetic exposure. Using an in vivo mouse model we demonstrate abnormal development of dendrite arbors and dendritic spines in newly generated dentate gyrus granule cell neurons of the hippocampus after a clinically relevant isoflurane anesthesia exposure conducted at an early postnatal age. Furthermore, we find that isoflurane causes a sustained increase in activity in the mechanistic target of rapamycin pathway, and that inhibition of this pathway with rapamycin not only reverses the observed changes in neuronal development, but also substantially improves performance on behavioral tasks of spatial learning and memory that are impaired by isoflurane exposure. We conclude that isoflurane disrupts the development of hippocampal neurons generated in the early postnatal period by activating a well-defined neurodevelopmental disease pathway and that this phenotype can be reversed by pharmacologic inhibition. PMID:28683067

Understanding of anesthesia machine function is enhanced with a transparent reality simulation.

PubMed

Fischler, Ira S; Kaschub, Cynthia E; Lizdas, David E; Lampotang, Samsun

2008-01-01

Photorealistic simulations may provide efficient transfer of certain skills to the real system, but by being opaque may fail to encourage deeper learning of the structure and function of the system. Schematic simulations that are more abstract, with less visual fidelity but make system structure and function transparent, may enhance deeper learning and optimize retention and transfer of learning. We compared learning effectiveness of these 2 modes of externalizing the output of a common simulation engine (the Virtual Anesthesia Machine, VAM) that models machine function and dynamics and responds in real time to user interventions such as changes in gas flow or ventilation. Undergraduate students (n = 39) and medical students (n = 35) were given a single, 1-hour guided learning session with either a Transparent or an Opaque version of the VAM simulation. The following day, the learners' knowledge of machine components, function, and dynamics was tested. The Transparent-VAM groups scored higher than the Opaque-VAM groups on a set of multiple-choice questions concerning conceptual knowledge about anesthesia machines (P = 0.009), provided better and more complete explanations of component function (P = 0.003), and were more accurate in remembering and inferring cause-and-effect dynamics of the machine and relations among components (P = 0.003). Although the medical students outperformed undergraduates on all measures, a similar pattern of benefits for the Transparent VAM was observed for these 2 groups. Schematic simulations that transparently allow learners to visualize, and explore, underlying system dynamics and relations among components may provide a more effective mental model for certain systems. This may lead to a deeper understanding of how the system works, and therefore, we believe, how to detect and respond to potentially adverse situations.

Plant anesthesia supports similarities between animals and plants: Claude Bernard's forgotten studies.

PubMed

Grémiaux, Alexandre; Yokawa, Ken; Mancuso, Stefano; Baluška, František

2014-01-01

The French scientist Claude Bernard (1813-1878) is famous for his discoveries in physiology and for introducing rigorous experimental methods to medicine and biology. One of his major technical innovations was the use of chemicals in order to disrupt normal physiological function to test hypotheses. But less known is his conviction that the physiological functions of all living organisms rely on the same underlying principles. He hypothesized that similarly to animals, plants are also able to sense changes in their environment. He called this ability "sensitivity." In order to test his ideas, he performed anesthesia on plants and the results of these experiments were presented in 1878 in "Leçonssur les phénomènes de la vie communs aux animaux et aux végétaux." The phenomena described by Claude Bernard more than a century ago are not fully understood yet. Here, we present a short overview of anesthetic effects in animals and we discuss how anesthesia affects plant movements, seed germination, and photosynthesis. Surprisingly, these phenomena may have ecological relevance, since stressed plants generate anesthetics such as ethylene and ether. Finally, we discuss Claude Bernard's interpretations and conclusions in the perspective of modern plant sciences.

Toward molecular mechanism of xenon anesthesia: a link to studies of xenon complexes with small aromatic molecules.

PubMed

Andrijchenko, Natalya N; Ermilov, Alexander Yu; Khriachtchev, Leonid; Räsänen, Markku; Nemukhin, Alexander V

2015-03-19

The present study illustrates the steps toward understanding molecular mechanism of xenon anesthesia by focusing on a link to the structures and spectra of intermolecular complexes of xenon with small aromatic molecules. A primary cause of xenon anesthesia is attributed to inhibition of N-methyl-D-aspartate (NMDA) receptors by an unknown mechanism. Following the results of quantum mechanics/molecular mechanics (QM/MM) and molecular dynamics (MD) calculations we report plausible xenon action sites in the ligand binding domain of the NMDA receptor, which are due to interaction of xenon atoms with aromatic amino-acid residues. We rely in these calculations on computational protocols adjusted in combined experimental and theoretical studies of intermolecular complexes of xenon with phenol. Successful reproduction of vibrational shifts in molecular species upon complexation with xenon measured in low-temperature matrices allowed us to select a proper functional form in density functional theory (DFT) approach for use in QM subsystems, as well as to calibrate force field parameters for MD simulations. The results of molecular modeling show that xenon atoms can compete with agonists for a place in the corresponding protein cavity, thus indicating their active role in anesthetic action.

A child with a difficult airway: what do I do next?

PubMed

Engelhardt, Thomas; Weiss, Markus

2012-06-01

Difficulties in pediatric airway management are common and continue to result in significant morbidity and mortality. This review reports on current concepts in approaching a child with a difficult airway. Routine airway management in healthy children with normal airways is simple in experienced hands. Mask ventilation (oxygenation) is always possible and tracheal intubation normally simple. However, transient hypoxia is common in these children usually due to unexpected anatomical and functional airway problems or failure to ventilate during rapid sequence induction. Anatomical airway problems (upper airway collapse and adenoid hypertrophy) and functional airway problems (laryngospasm, bronchospasm, insufficient depth of anesthesia and muscle rigidity, gastric hyperinflation, and alveolar collapse) require urgent recognition and treatment algorithms due to insufficient oxygen reserves. Early muscle paralysis and epinephrine administration aids resolution of these functional airway obstructions. Children with an 'impaired' normal (foreign body, allergy, and inflammation) or an expected difficult (scars, tumors, and congenital) airway require careful planning and expertise. Training in the recognition and management of these different situations as well as a suitably equipped anesthesia workstation and trained personnel are essential. The healthy child with an unexpected airway problem requires clear strategies. The 'impaired' normal pediatric airway may be handled by anesthetists experienced with children, whereas the expected difficult pediatric airway requires dedicated pediatric anesthesia specialist care and should only be managed in specialized centers.

Deep Brain Stimulation for Tremor Tractographic Versus Traditional (DISTINCT): Study Protocol of a Randomized Controlled Feasibility Trial.

PubMed

Sajonz, Bastian Elmar Alexander; Amtage, Florian; Reinacher, Peter Christoph; Jenkner, Carolin; Piroth, Tobias; Kätzler, Jürgen; Urbach, Horst; Coenen, Volker Arnd

2016-12-22

Essential tremor is a movement disorder that can result in profound disability affecting the quality of life. Medically refractory essential tremor can be successfully reduced by deep brain stimulation (DBS) traditionally targeting the thalamic ventral intermediate nucleus (Vim). Although this structure can be identified with magnetic resonance (MR) imaging nowadays, Vim-DBS electrodes are still implanted in the awake patient with intraoperative tremor testing to achieve satisfactory tremor control. This can be attributed to the fact that the more effective target of DBS seems to be the stimulation of fiber tracts rather than subcortical nuclei like the Vim. There is evidence that current coverage of the dentatorubrothalamic tract (DRT) results in good tremor control in Vim-DBS. Diffusion tensor MR imaging (DTI) tractography-assisted stereotactic surgery targeting the DRT would therefore not rely on multiple trajectories and intraoperative tremor testing in the awake patient, bearing the potential of more patient comfort and reduced operation-related risks. This is the first randomized controlled trial comparing DTI tractography-assisted stereotactic surgery targeting the DRT in general anesthesia with stereotactic surgery of thalamic/subthalamic region as conventionally used. This clinical pilot trial aims at demonstrating safety of DTI tractography-assisted stereotactic surgery in general anesthesia and proving its equality compared to conventional stereotactic surgery with intraoperative testing in the awake patient. The Deep Brain Stimulation for Tremor Tractographic Versus Traditional (DISTINCT) trial is a single-center investigator-initiated, randomized, controlled, observer-blinded trial. A total of 24 patients with medically refractory essential tremor will be randomized to either DTI tractography-assisted stereotactic surgery targeting the DRT in general anesthesia or stereotactic surgery of the thalamic/subthalamic region as conventionally used. The primary objective is to assess the tremor reduction, obtained by the Fahn-Tolosa-Marin Tremor Rating Scale in the 2 treatment groups. Secondary objectives include (among others) assessing the quality of life, optimal electrode contact positions, and safety of the intervention. The study protocol has been approved by the independent ethics committee of the University of Freiburg. Recruitment to the DISTINCT trial opened in September 2015 and is expected to close in June 2017. At the time of manuscript submission the trial is open to recruitment. The DISTINCT trial is the first to compare DTI tractography-assisted stereotactic surgery with target point of the DRT in general anesthesia to stereotactic surgery of the thalamic/subthalamic region as conventionally used. It can serve as a cornerstone for the evolving technique of DTI tractography-assisted stereotactic surgery. ClinicalTrials.gov NCT02491554; https://clinicaltrials.gov/ct2/show/NCT02491554 (Archived by WebCite at http://www.webcitation.org/6mezLnB9D). German Clinical Trials Register DRKS00008913; http://drks-neu.uniklinik-freiburg.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00008913 (Archived by WebCite at http://www.webcitation.org/6mezCtxhS). ©Bastian Elmar Alexander Sajonz, Florian Amtage, Peter Christoph Reinacher, Carolin Jenkner, Tobias Piroth, Jürgen Kätzler, Horst Urbach, Volker Arnd Coenen. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 22.12.2016.

Anterior Ethmoidal Nerve Block in Prevention of Postoperative Agitation

ClinicalTrials.gov

2018-02-08

Postoperative Agitation: Impaired Awareness, Abnormal Cognitive Function, Confusion, and Verbal and Physical Agitation During Recovery From General Anesthesia; Deviated Nasal Septum; Chronic Rhinosinusitis (Diagnosis); Nasal Polyps

Implementation of Intraoperative Neurophysiological Monitoring during Endovascular Procedures in the Central Nervous System.

PubMed

Martinez Piñeiro, Alicia; Cubells, Carles; Garcia, Pablo; Castaño, Carlos; Dávalos, Antonio; Coll-Canti, Jaume

2015-03-01

Intraoperative monitoring (IOM) has been used in different surgical disciplines since the 1980s. Nonetheless, regular routine use of IOM in interventional neuroradiology units has only been reported in a few centers. The aim of this study is to report our experience, 1 year after deciding to implement standardized IOM during endovascular treatment of vascular abnormalities of the central nervous system. Basic recordings included somatosensory-evoked potentials (SEPs) and motor-evoked potentials (MEPs). Corticobulbar motor-evoked potentials and flash-visual-evoked potentials were also recorded depending on the topography of the lesion. Intra-arterial provocative tests (PTs) with amobarbital and lidocaine were also performed. All patients except 1 were under total intravenous anesthesia. Clinical outcome was assessed prospectively and correlated with IOM events. Twelve patients and 15 procedures were monitored during the inclusion period. Significant IOM events were detected during 3 of the 15 procedures (20%). We observed temporary MEP changes in 2 cases which resolved after interruption of the embolization or application of corrective measures, leaving no postoperative neurological deficits. In 1 case, persistent SEP and MEP deterioration was detected secondary to a frontal hematoma, resulting in mild sensory-motor deficit in the right upper extremity after the procedure. Overall, 12 PTs (4 spinal cord and 8 brain abnormalities) were performed using lidocaine and sodium amytal injections. One positive result occurred after the injection of lidocaine. No false negatives were detected. IOM may provide continuous real-time data about the functional status of eloquent areas and pathways of the central nervous system in patients under general anesthesia. It therefore allows us to detect early neurological damage in time to perform specific actions that may prevent irreversible neurological deficits.

Xenon for the prevention of postoperative delirium in cardiac surgery: study protocol for a randomized controlled clinical trial.

PubMed

Al Tmimi, Layth; Van de Velde, Marc; Herijgers, Paul; Meyns, Bart; Meyfroidt, Geert; Milisen, Koen; Fieuws, Steffen; Coburn, Mark; Poesen, Koen; Rex, Steffen

2015-10-09

Postoperative delirium (POD) is a manifestation of acute postoperative brain dysfunction that is frequently observed after cardiac surgery. POD is associated with short-term complications such as an increase in mortality, morbidity, costs and length of stay, but can also have long-term sequelae, including persistent cognitive deficits, loss of independence, and increased mortality for up to 2 years. The noble gas xenon has been demonstrated in various models of neuronal injury to exhibit remarkable neuroprotective properties. We therefore hypothesize that xenon anesthesia reduces the incidence of POD in elderly patients undergoing cardiac surgery with the use of cardiopulmonary bypass. One hundred and ninety patients, older than 65 years, and scheduled for elective cardiac surgery, will be enrolled in this prospective, randomized, controlled trial. Patients will be randomized to receive general anesthesia with either xenon or sevoflurane. Primary outcome parameter will be the incidence of POD in the first 5 postoperative days. The occurrence of POD will be assessed by trained research personnel, blinded to study group, with the validated 3-minute Diagnostic Confusion Assessment Method (3D-CAM) (on the intensive care unit in its version specifically adapted for the ICU), in addition to chart review and the results of delirium screening tools that will be performed by the bedside nurses). Secondary outcome parameters include duration and severity of POD, and postoperative cognitive function as assessed with the Mini-Mental State Examination. Older patients undergoing cardiac surgery are at particular risk to develop POD. Xenon provides remarkable hemodynamic stability and has been suggested in preclinical studies to exhibit neuroprotective properties. The present trial will assess whether the promising profile of xenon can be translated into a better outcome in the geriatric population. EudraCT Identifier: 2014-005370-11 (13 May 2015).

Sensory transduction of weak electromagnetic fields: role of glutamate neurotransmission mediated by NMDA receptors.

PubMed

Frilot, C; Carrubba, S; Marino, A A

2014-01-31

Subliminal electromagnetic fields (EMFs) triggered nonlinear evoked potentials in awake but not anesthetized animals, and increased glucose metabolism in the hindbrain. Field detection occurred somewhere in the head and possibly was an unrecognized function of sensory neurons in facial skin, which synapse in the trigeminal nucleus and project to the thalamus via glutamate-dependent pathways. If so, anesthetic agents that antagonize glutamate neurotransmission would be expected to degrade EMF-evoked potentials (EEPs) to a greater extent than agents having different pharmacological effects. We tested the hypothesis using ketamine which blocks N-methyl-d-aspartate (NMDA) receptors (NMDARs), and xylazine which is an α₂-adrenoreceptor agonist. Electroencephalograms (EEGs) of rats were examined using recurrence analysis to observe EEPs in the presence and absence of ketamine and/or xylazine anesthesia. Auditory evoked potentials (AEPs) served as positive controls. The frequency of observation of evoked potentials in a given condition (wake or anesthesia) was compared with that due to chance using the Fisher's exact test. EEPs were observed in awake rats but not while they were under anesthesia produced using a cocktail of xylazine and ketamine. In another experiment each rat was measured while awake and while under anesthesia produced using either xylazine or ketamine. EEPs and AEPs were detected during wake and under xylazine (P<0.05 in each of the four measurements). In contrast, neither EEPs nor AEPs were observed when anesthesia was produced partly or wholly using ketamine. The duration and latency of the EEPs was unaltered by xylazine anesthesia. The afferent signal triggered by the transduction of weak EMFs was likely mediated by NMDAR-mediated glutamate neurotransmission. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

[Propofol anesthesia for a patient with progressive muscular dystrophy].

PubMed

Egi, Moritoki; Tokioka, Hiroaki; Chikai, Takashi; Fukushima, Tomihiro; Ishizu, Tomoko; Tanaka, Toshiaki; Kosogabe, Yoshinori

2002-02-01

We gave propofol anesthesia to a patient with limb-girdle type of progressive muscular dystrophy. A 42 year-old male was to have skin graft for third degree burn. His respiratory function test showed %VC of 73.6% and %FEV1.0 of 107.6%. Arterial blood gas data were within normal ranges. He was anesthetized with propofol, fentanyl, vecuronium and nitrous oxide. During position change, Wenckebach type of second degree AV block occurred. AV block returned to sinus rhythm easily by injection of ephedrine hydrochloride and atropine sulfate, and reduction of propofol infusion rate. There were no perioperative respiratory complications and no clinical manifestations of malignant hyperthermia. Propofol anesthesia is suitable for limb-girdle type of progressive muscular dystrophy, because of very little possibility of triggering malignant hyperthermia, rapid awaking, minimal residual effects of the respiratory system, and easiness in controlling anesthetic depth.

Relationship between intraoperative regional cerebral oxygen saturation trends and cognitive decline after total knee replacement: a post-hoc analysis

PubMed Central

2014-01-01

Background Bilateral regional brain oxygen saturation (rSO2) trends, reflecting intraoperative brain oxygen imbalance, could warn of brain dysfunction. Various types of cognitive impairment, such as memory decline, alterations in executive function or subjective complaints, have been described three months after surgery. Our aim was to explore the potential utility of rSO2 values as a warning sign for the development of different types of decline in postoperative psychological function. Methods Observational post-hoc analysis of data for the patient sample (n = 125) of a previously conducted clinical trial in patients over the age of 65 years undergoing total knee replacement under spinal anesthesia. Demographic, hemodynamic and bilateral rSO2 intraoperative values were recorded. An absolute rSO2 value of <50% or a reduction of >20% or >25% below baseline were chosen as relevant cutoffs. Composite function test scores were created from baseline to three months for each patient and adjusted for the mean (SD) score changes for a control group (n = 55). Tests were used to assess visual-motor coordination and executive function (VM-EF) (Wechsler Digit Symbol-Coding and Visual Reproduction, Trail Making Test) and memory (Auditory Verbal Learning, Wechsler Memory Scale); scales were used to assess psychological symptoms. Results We observed no differences in baseline rSO2 values; rSO2 decreased significantly in all patients during surgery (P < 0.0001). Seventy-five patients (60%) had no sign of cognitive decline or psychological symptoms. Twenty-one patients (16.8%) had memory decline, 3 (2.4%) had VM-EF decline, and 33 (26.4%) had psychological symptoms. Left and right rSO2 values were asymmetric in patients who had memory decline (mean [SD] left-right ratio of 95.03 [8.51] vs 101.29 [6.7] for patients with no changes, P = 0.0012). The mean right-left difference in rSO2 was also significant in these patients (-2.87% [4.73%], lower on the right, P = 0.0034). Conclusions Detection of a trend to asymmetry in rSO2 values can warn of possible postoperative onset of memory decline. Psychological symptoms and memory decline were common three months after knee replacement in our patients over the age of 65 years. PMID:25061427

Relationship between intraoperative regional cerebral oxygen saturation trends and cognitive decline after total knee replacement: a post-hoc analysis.

PubMed

Salazar, Fátima; Doñate, Marta; Boget, Teresa; Bogdanovich, Ana; Basora, Misericordia; Torres, Ferran; Gracia, Isabel; Fàbregas, Neus

2014-01-01

Bilateral regional brain oxygen saturation (rSO2) trends, reflecting intraoperative brain oxygen imbalance, could warn of brain dysfunction. Various types of cognitive impairment, such as memory decline, alterations in executive function or subjective complaints, have been described three months after surgery. Our aim was to explore the potential utility of rSO2 values as a warning sign for the development of different types of decline in postoperative psychological function. Observational post-hoc analysis of data for the patient sample (n = 125) of a previously conducted clinical trial in patients over the age of 65 years undergoing total knee replacement under spinal anesthesia. Demographic, hemodynamic and bilateral rSO2 intraoperative values were recorded. An absolute rSO2 value of <50% or a reduction of >20% or >25% below baseline were chosen as relevant cutoffs. Composite function test scores were created from baseline to three months for each patient and adjusted for the mean (SD) score changes for a control group (n = 55). Tests were used to assess visual-motor coordination and executive function (VM-EF) (Wechsler Digit Symbol-Coding and Visual Reproduction, Trail Making Test) and memory (Auditory Verbal Learning, Wechsler Memory Scale); scales were used to assess psychological symptoms. We observed no differences in baseline rSO2 values; rSO2 decreased significantly in all patients during surgery (P < 0.0001). Seventy-five patients (60%) had no sign of cognitive decline or psychological symptoms. Twenty-one patients (16.8%) had memory decline, 3 (2.4%) had VM-EF decline, and 33 (26.4%) had psychological symptoms. Left and right rSO2 values were asymmetric in patients who had memory decline (mean [SD] left-right ratio of 95.03 [8.51] vs 101.29 [6.7] for patients with no changes, P = 0.0012). The mean right-left difference in rSO2 was also significant in these patients (-2.87% [4.73%], lower on the right, P = 0.0034). Detection of a trend to asymmetry in rSO2 values can warn of possible postoperative onset of memory decline. Psychological symptoms and memory decline were common three months after knee replacement in our patients over the age of 65 years.

[Impacts of the different frequencies of electroacupunctrue on cognitive function in patients after abdominal operation under compound anesthesia of acupuncture and drugs].

PubMed

Lin, Shun-Yan; Gao, Ju; Yin, Zheng-Lu; Zhou, Luo-Jing; Chen, Xin

2013-12-01

To observe the impacts of different frequencies of electroacupuncture (EA) on post-operative cognitive function and the change in serum S-100beta protein under the compound anesthesia of acupuncture and drugs. One hundred and twenty-four patients of abdominal operation at selective time were randomized into a routine drug anesthesia group (group A, 24 cases), a meridian point 2 Hz group (group B, 26 cases), a me ridian point 2 Hz/100 Hz group (group C, 25 cases), a meridian point 100 Hz group (group D, 24 cases) and a transcutaneous acupoint electric stimulation 2 Hz/100 Hz group (group E, 25 cases). In group A, the endotrachea-lgeneral anesthesia was applied. In the rest groups, the acupuncture anesthesia was induced for 30 min before the endotracheal general anesthesia, at Baihui (GV 20), Yintang (GV 29) and Neiguan (PC 6), with G6805-2 electric acupuncture apparatus used. In group B, the continuous wave and 2Hz in frequency were selected. In group C, the disperse-dense wave and 2 Hz/100 Hz in frequency were selected. In group D, the continuous wave and 100 Hz in frequency were selected. In group E, the disperse-dense wave and 2 Hz/100 Hz in frequency were selected, and the electrode pads were stick on the acupoints and connected with the electric stimulation till the end of operation. Mini-mental state examination (MMSE) was adopted to evaluate and record the changes in cognitive function 1 day before operation and on the 3rd day after operation. The conditions of post-operative cognitive dysfunction (POCD) in the patients and the changes in serum S-100beta protein were monitored before and at the end of operation. The incidence rate of POCD on the 3rd day after operation was 41.7% (10/24) in group A. The incidence rates of POCD were 26.9% (7/26), 16.0% (4/25), 33.3% (8/24) and 16.0% (4/25) in group B, C, D and E separately. Compared with group A, the incidence rate of PCOD in group B, C, D and E were reduced (all P<0.05), the incidence rate in group C and E were lower than that in groups B and D (all P<0.05). At the end of operation, the level of serumS-100beta protein was (0.186 +/- 0.027) microg/L in group A, the levels were (0.165 +/- 0. 028) microg/L, (0.166 +/- 0.027) microg/L, (0.163 +/- 0.025) microg/L and (0.164 +/- 0.025) microg/L in group B, C, D and E separately. The levels of serum S-100beta protein in group B, C, D and E were lower than that in group A separately (all P<0.05). The general anesthesia assisted with EA at different frequencies reduces the incidence of cognitive dysfunctionand, decreases the level of serum S-100beta protein after intestinal cancer resection. The effects of the meridian point electric stimulation at 2 Hz/100 Hz and the transcutaneous electric stimulation at 2 Hz/100 Hz are the best. Hence, these two approaches of anesthesia deserve to be recommended practically.

Chest physiotherapy during anesthesia for children with cystic fibrosis: effects on respiratory function.

PubMed

Tannenbaum, E; Prasad, S A; Dinwiddie, R; Main, Eleanor

2007-12-01

Physiotherapists sometimes use elective surgical procedures for children with cystic fibrosis as an opportunity to perform physiotherapy treatments during anesthesia. These treatments theoretically facilitate direct endotracheal airway clearance and compensate for any post-operative respiratory deterioration related to the anaesthetic and surgery. MATERIALS, PATIENTS, AND METHODS: Children were randomized either to receive physiotherapy or not following anesthesia and intubation. Respiratory mechanics (C(rs) and R(rs)), tidal volume, and peak inspiratory pressure (PIP) were measured immediately before and after physiotherapy. FEV(1) was measured before and after surgery and post-operative physiotherapy requirements were recorded. Eighteen patients, mean age 12 years (range 2.8-15 years) were recruited, with nine in each group. Both groups showed a non-significant decline in FEV(1) the day after surgery compared with pre-operative values (-5.8%: physiotherapy and -7.1%: control). Both PIP and R(rs) increased significantly following physiotherapy (within- and between-groups, P < 0.05). In addition, there was a significant within-group reduction in C(rs) after physiotherapy which approached significance between-groups (P = 0.07). There were no significant within- or between-group differences in tidal volume following treatment in either group. The unanticipated decline in respiratory function immediately following physiotherapy was short-lived and not discernible in longer term outcomes measured by FEV(1) or physiotherapy requirements post-operatively. If respiratory physiotherapy under anesthesia is considered necessary and the benefits of removing secretions are deemed to outweigh the short-term risks, it may be necessary for the anaesthetist to consider modifying ventilatory support to counteract any short-term negative effects of the treatment.

Intraoperative Clinical Decision Support for Anesthesia: A Narrative Review of Available Systems.

PubMed

Nair, Bala G; Gabel, Eilon; Hofer, Ira; Schwid, Howard A; Cannesson, Maxime

2017-02-01

With increasing adoption of anesthesia information management systems (AIMS), there is growing interest in utilizing AIMS data for intraoperative clinical decision support (CDS). CDS for anesthesia has the potential for improving quality of care, patient safety, billing, and compliance. Intraoperative CDS can range from passive and post hoc systems to active real-time systems that can detect ongoing clinical issues and deviations from best practice care. Real-time CDS holds the most promise because real-time alerts and guidance can drive provider behavior toward evidence-based standardized care during the ongoing case. In this review, we describe the different types of intraoperative CDS systems with specific emphasis on real-time systems. The technical considerations in developing and implementing real-time CDS are systematically covered. This includes the functional modules of a CDS system, development and execution of decision rules, and modalities to alert anesthesia providers concerning clinical issues. We also describe the regulatory aspects that affect development, implementation, and use of intraoperative CDS. Methods and measures to assess the effectiveness of intraoperative CDS are discussed. Last, we outline areas of future development of intraoperative CDS, particularly the possibility of providing predictive and prescriptive decision support.

Applications of magnesium sulfate in obstetrics and anesthesia.

PubMed

Barbosa, Fabiano Timbó; Barbosa, Luciano Timbó; Jucá, Mário Jorge; Cunha, Rafael Martins da

2010-01-01

Magnesium is predominantly an intracellular ion. Its blocking effects on NMDA receptors are responsible for the analgesic and sedative characteristics of this ion. The objective of this study was to review the physiology, pharmacology, and decreased plasma levels of magnesium, as well as its applications in obstetrics and anesthesia. Magnesium is an intracellular cation with multiple functions: it is a cofactor for enzymes of the glucose metabolism and those that participate in the degradation of nucleic acids, proteins, and fatty acids; it regulates the movements of transmembrane ions; and it intervenes in the activity of several enzymes. Critical patients have a tendency to develop hypomagnesemia, and the treatment consists in correcting the cause, whenever possible, and replacement of magnesium. A reduction in the minimum alveolar concentration (MAC) of inhalational agents in animals and the use of opioids in humans under anesthesia has been demonstrated. Magnesium sulfate has been used in obstetrics with good results, inhibiting premature labor and in the treatment of eclampsia-associated seizures. It is potentially analgesic and sedative, and could be used as adjuvant during general anesthesia, attenuating the blood pressure response to tracheal intubation and decreasing the need of anesthetics.

A case of a power failure in the operating room.

PubMed

Yasny, Jeffrey; Soffer, Robert

2005-01-01

In the operating room, safely administering anesthesia amidst a major power failure can instantly present one with a formidable challenge. A case is presented involving a 23-year-old healthy woman who underwent a complex oral and maxillofacial surgery to correct a dentofacial deformity. Three hours into the case and with the patient's maxilla downfractured, the overhead surgical lights blacked out, and there was an apparent loss of the anesthesia machine's ability to function. Providing adequate oxygenation, ventilation, anesthesia levels, monitoring of vital signs, and transportation of the patient were some of the challenges faced, and the response to this unexpected event is recounted. The importance of one's familiarity with an anesthesia machine's backup battery supply, routinely checking machinery, ensuring that appropriate and sufficient supplies are readily available, exercising calm leadership with clear communication, and formulating a clear plan with backup alternatives are discussed. Various recommendations are proposed with respect to the preparation for and the prevention of a power failure in the operating room. This report's account of events is aimed to "shed some light" on this topic, serve as a check of one's own preparedness, and facilitate the optimal management of a similarly unexpected incident.

Age at Exposure to Surgery and Anesthesia in Children and Association With Mental Disorder Diagnosis.

PubMed

Ing, Caleb; Sun, Ming; Olfson, Mark; DiMaggio, Charles J; Sun, Lena S; Wall, Melanie M; Li, Guohua

2017-12-01

Animals exposed to anesthetics during specific age periods of brain development experience neurotoxicity, with neurodevelopmental changes subsequently observed during adulthood. The corresponding vulnerable age in children, however, is unknown. An observational cohort study was performed using a longitudinal dataset constructed by linking individual-level Medicaid claims from Texas and New York from 1999 to 2010. This dataset was evaluated to determine whether the timing of exposure to anesthesia ≤5 years of age for a single common procedure (pyloromyotomy, inguinal hernia, circumcision outside the perinatal period, or tonsillectomy and/or adenoidectomy) is associated with increased subsequent risk of diagnoses for any mental disorder, or specifically developmental delay (DD) such as reading and language disorders, and attention deficit hyperactivity disorder (ADHD). Exposure to anesthesia and surgery was evaluated in 11 separate age at exposure categories: ≤28 days old, >28 days and ≤6 months, >6 months and ≤1 year, and 6-month age intervals between >1 year old and ≤5 years old. For each exposed child, 5 children matched on propensity score calculated using sociodemographic and clinical covariates were selected for comparison. Cox proportional hazards models were used to measure the hazard ratio of a mental disorder diagnosis associated with exposure to surgery and anesthesia. A total of 38,493 children with a single exposure and 192,465 propensity score-matched children unexposed before 5 years of age were included in the analysis. Increased risk of mental disorder diagnosis was observed at all ages at exposure with an overall hazard ratio of 1.26 (95% confidence interval [CI], 1.22-1.30), which did not vary significantly with the timing of exposure. Analysis of DD and ADHD showed similar results, with elevated hazard ratios distributed evenly across all ages, and overall hazard ratios of 1.26 (95% CI, 1.20-1.32) for DD and 1.31 (95% CI, 1.25-1.37) for ADHD. Children who undergo minor surgery requiring anesthesia under age 5 have a small but statistically significant increased risk of mental disorder diagnoses and DD and ADHD diagnoses, but the timing of the surgical procedure does not alter the elevated risks. Based on these findings, there is little support for the concept of delaying a minor procedure to reduce long-term neurodevelopmental risks of anesthesia in children. In evaluating the influence of age at exposure, the types of procedures included may need to be considered, as some procedures are associated with specific comorbid conditions and are only performed at certain ages.