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Sample records for hypothermia induced

  1. Method for inducing hypothermia

    DOEpatents

    Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

    2003-04-15

    Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

  2. Method for inducing hypothermia

    DOEpatents

    Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

    2005-11-08

    Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

  3. Method for inducing hypothermia

    SciTech Connect

    Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

    2008-09-09

    Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

  4. Role of neurotensin in radiation-induced hypothermia in rats

    SciTech Connect

    Kandasamy, S.B.; Hunt, W.A.; Harris, A.H. )

    1991-05-01

    The role of neurotensin in radiation-induced hypothermia was examined. Intracerebroventricular (ICV) administration of neurotensin produced dose-dependent hypothermia. Histamine appears to mediate neurotensin-induced hypothermia because the mast cell stabilizer disodium cromoglycate and antihistamines blocked the hypothermic effects of neurotensin. An ICV pretreatment with neurotensin antibody attenuated neurotensin-induced hypothermia, but did not attenuate radiation-induced hypothermia, suggesting that radiation-induced hypothermia was not mediated by neurotensin.

  5. Hypothermia-induced acute kidney injury in an elderly patient.

    PubMed

    Yoon, Hyun Ju; Kim, Mun Chul; Park, Jae Woo; Yang, Min A; Lee, Cheon Beom; Sun, In O; Lee, Kwang Young

    2014-01-01

    Hypothermia, defined as an unintentional decline in the core body temperature to below 35℃, is a life-threatening condition. Patients with malnutrition and diabetes mellitus as well as those of advanced age are at high risk for accidental hypothermia. Due to the high mortality rates of accidental hypothermia, proper management is critical for the wellbeing of patients. Accidental hypothermia was reported to be associated with acute kidney injury (AKI) in over 40% of cases. Although the pathogenesis remains to be elucidated, vasoconstriction and ischemia in the kidney were considered to be the main mechanisms involved. Cases of AKI associated with hypothermia have been reported worldwide, but there have been few reports of hypothermia-induced AKI in Korea. Here, we present a case of hypothermia-induced AKI that was treated successfully with rewarming and supportive care.

  6. Hypothermia

    MedlinePlus

    Cold weather can affect your body in different ways. You can get frostbite, which is an injury to the ... Anyone who spends much time outdoors in cold weather can get hypothermia. You can also get it ...

  7. [Hypothermia].

    PubMed

    García Iriarte, Antxon; Sáenz Mendía, Raquel; Marín Fernández, Blanca

    2010-01-01

    A deep understanding about the causes and situations which predispose a patient to hypothermia can prevent its progression and the emergence of complications which present life-threatening risks and can lead to irreversible organ deterioration. The distinct degrees of hypothermia require a diagnosis and a distinct therapeutic treatment which share common pillars based on: the need to employ general measures which counterarrest the deterioration of those organs caused by heat loss; and the use of internal or external reheating methods which vary due to the degree of hypothermia and the hemodynamic stability of the patient. In moderate or severe cases, a nurse's role, as one who collaborates in patient treatment, requires paying special attention to strict monitoring of vital constants, neurological, metabolic and cardio-respiratory signs, as well as collaborating in various therapeutic procedures. As a nursing diagnosis, hypothermia refers to those situations in which a nurse's professional competence capacitates he/she to carry out actions which resolve that prejudicial situation a patient faces.

  8. Inducing Therapeutic Hypothermia in Cardiac Arrest Caused by Lightning Strike.

    PubMed

    Scantling, Dane; Frank, Brian; Pontell, Mathew E; Medinilla, Sandra

    2016-09-01

    Only limited clinical scenarios are grounds for induction of therapeutic hypothermia. Its use in traumatic cardiac arrests, including those from lightning strikes, is not well studied. Nonshockable cardiac arrest rhythms have only recently been included in resuscitation guidelines. We report a case of full neurological recovery with therapeutic hypothermia after a lightning-induced pulseless electrical activity cardiac arrest in an 18-year-old woman. We also review the important pathophysiology of lightning-induced cardiac arrest and neurologic sequelae, elaborate upon the mechanism of therapeutic hypothermia, and add case-based evidence in favor of the use of targeted temperature management in lightning-induced cardiac arrest.

  9. Role of Neurotensin in Radiation-Induced Hypothermia in Rats

    DTIC Science & Technology

    1991-01-01

    variety of behavioral and physiolog- of Neurotensin in Radiation-induced Hypothermia in Rat.A- ical effects, including the stimulation of histamine relmeas...induction of hypothermia, after intracisternal or intraven- was examined. Intracerebroventricular (IafCV) adminis-tration of tricular administration...1S-4 7). ’The purposes of this study ne-urotensin produced dose-dependent hypoihermia. Histamine were to investigate the role of neurotensin in

  10. Alpha-lipoic acid protects mitochondrial enzymes and attenuates lipopolysaccharide-induced hypothermia in mice

    EPA Science Inventory

    Abstract: Hypothermia is a key symptom of sepsis and the mechanism(s) leading to hypothermia during sepsis is largely unknown. To investigate a potential mechanism and find an effective treatment for hypothermia in sepsis, we induced hypothermia in mice by lipopolysaccharide (LP...

  11. Naltrexone-induced hypothermia in the rat.

    PubMed

    Ary, M; Chesarek, W; Sorensen, S M; Lomax, P

    1976-10-01

    Naltrexone, in relatively high doses, has been reported to cause a fall in body temperature in human ex-heroin addicts who had been abstinent for at least 6 weeks. The underlying mechanism of this hypothermic effect has been investigated in rats. The first consideration was that the temperature change was a reflection of delayed withdrawal but rats implanted with a morphine pellet 45 days earlier showed no significant change in temperature after a dose of naltrexone that caused marked withdrawal hypothermia in dependent rats implanted 3 days previously. A fall in core temperature was only induced in rats after doses of 80 and 160 mg/kg i.p. of naltrexone. Behavioral thermoregulatory studies revealed that the animals correct the falling body temperature by increased exposure to a radiant heat source indicating that the central thermostats had not been significantly affected by the drug. These data suggest that the major component in the hypothermic effect of naltrexone is activation of efferent heat loss pathways or peripheral heat loss mechanisms. Due to current suggestions that opiate receptors might represent the receptors for an endogenous transmitter the results are discussed in relation to this consideration. When compared to the sites and mechanism of action of opiates on thermoregulation the results with naltrexone lend little support to the hypothesis that the fall in temperature is due to displacement of an endogenous substance from central opiate receptors.

  12. Mild Hypothermia Attenuates the Anesthetic Isoflurane-Induced Cytotoxicity

    PubMed Central

    Li, Cheng; Dong, Yuanlin; Chen, Dan; Xie, Zhongcong; Zhang, Yiying

    2017-01-01

    The commonly used inhalation anesthetic isoflurane has been reported to induce DNA damage and cytotoxicity. However, the methods to attenuate these effects remain largely to be determined. Mild hypothermia has neuroprotective effects. We therefore set out to assess whether mild hypothermia could protect the isoflurane-induced DNA damage and cytotoxicity. Moreover, we investigated the underlying mechanisms by assessing the effects of mild hypothermia on the isoflurane-induced changes in ATP levels. H4 human neuroglioma cells were treated with 2% isoflurane for 3 or 6 h with and without mild hypothermia (35°C). We assessed the cell viability by using 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and lactate dehydrogenase (LDH) assay. We determined DNA damage by measuring levels of phosphorylation of the histone protein H2A variant X at Ser139 (γH2A.X), the marker of DNA damage. We also measured ATP levels in the cells. Here we showed that the treatment with 2% isoflurane for 6 h induced cytotoxicity and DNA damage in the cells. Moreover, the treatment with 2% isoflurane for 3 h decreased ATP levels without inducing cytotoxicity. Mild hypothermia attenuated the isoflurane-induced cytotoxicity, DNA damage, and ATP reduction in the cells. Taken together, these data suggest that the isoflurane-induced reduction in ATP levels occurred before the isoflurane-induced cytotoxicity. Isoflurane may induce DNA damage and cause cytotoxicity through reducing ATP levels. Mild hypothermia would ameliorate isoflurane-induced DNA damage and cytotoxicity by attenuating the isoflurane-induced reduction in ATP levels. These pilot studies have established a system and will promote the future investigations of anesthesia neurotoxicity. PMID:28228717

  13. Mild Hypothermia Attenuates the Anesthetic Isoflurane-Induced Cytotoxicity.

    PubMed

    Li, Cheng; Dong, Yuanlin; Chen, Dan; Xie, Zhongcong; Zhang, Yiying

    2017-01-01

    The commonly used inhalation anesthetic isoflurane has been reported to induce DNA damage and cytotoxicity. However, the methods to attenuate these effects remain largely to be determined. Mild hypothermia has neuroprotective effects. We therefore set out to assess whether mild hypothermia could protect the isoflurane-induced DNA damage and cytotoxicity. Moreover, we investigated the underlying mechanisms by assessing the effects of mild hypothermia on the isoflurane-induced changes in ATP levels. H4 human neuroglioma cells were treated with 2% isoflurane for 3 or 6 h with and without mild hypothermia (35°C). We assessed the cell viability by using 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and lactate dehydrogenase (LDH) assay. We determined DNA damage by measuring levels of phosphorylation of the histone protein H2A variant X at Ser139 (γH2A.X), the marker of DNA damage. We also measured ATP levels in the cells. Here we showed that the treatment with 2% isoflurane for 6 h induced cytotoxicity and DNA damage in the cells. Moreover, the treatment with 2% isoflurane for 3 h decreased ATP levels without inducing cytotoxicity. Mild hypothermia attenuated the isoflurane-induced cytotoxicity, DNA damage, and ATP reduction in the cells. Taken together, these data suggest that the isoflurane-induced reduction in ATP levels occurred before the isoflurane-induced cytotoxicity. Isoflurane may induce DNA damage and cause cytotoxicity through reducing ATP levels. Mild hypothermia would ameliorate isoflurane-induced DNA damage and cytotoxicity by attenuating the isoflurane-induced reduction in ATP levels. These pilot studies have established a system and will promote the future investigations of anesthesia neurotoxicity.

  14. Nitrous oxide-induced hypothermia in the rat

    SciTech Connect

    Quock, R.M.; Panek, R.W.; Kouchich, F.J.; Rosenthal, M.A.

    1987-08-10

    Exposure of rats to high levels of nitrous oxide (N2O) in oxygen reduced body temperature in a concentration-related manner. The hypothermia was partly reversed by pretreatment with naloxone but not naltrexone. But in rats rendered tolerant to morphine by pellet implantation, exposure to 75% N2O/25% O2 evoked a marked hypothermia similar to that observed in morphine-naive animals. In another experiment, the hypothermic effect of chloral hydrate was also sensitive to antagonism by pretreatment with naloxone but not naltrexone. These observations lead the authors to suspect that N2O-induced hypothermia in rats is possibly not mediated by opiate receptors. The thermotropic activity of N2O may result from some non-opioid action of N2O. Its selective antagonism by naloxone (but not naltrexone) may be due to a unique non-opioid analeptic action of naloxone. 32 references, 4 figures.

  15. Coagulopathy induced by acidosis, hypothermia and hypocalcaemia in severe bleeding.

    PubMed

    De Robertis, E; Kozek-Langenecker, S A; Tufano, R; Romano, G M; Piazza, O; Zito Marinosci, G

    2015-01-01

    Acidosis, hypothermia and hypocalcaemia are determinants for morbidity and mortality during massive hemorrhages. However, precise pathological mechanisms of these environmental factors and their potential additive or synergistic anticoagulant and/or antiplatelet effects are not fully elucidated and are at least in part controversial. Best available evidences from experimental trials indicate that acidosis and hypothermia progressively impair platelet aggregability and clot formation. Considering the cell-based model of coagulation physiology, hypothermia predominantly prolongs the initiation phase, while acidosis prolongs the propagation phase of thrombin generation. Acidosis increases fibrinogen breakdown while hypothermia impairs its synthesis. Acidosis and hypothermia have additive effects. The effect of hypocalcaemia on coagulopathy is less investigated but it appears that below the cut-off of 0.9 mmol/L, several enzymatic steps in the plasmatic coagulation system are blocked while above that cut-off effects remain without clinical sequalae. The impact of environmental factor on hemostasis is underestimated in clinical practice due to our current practice of using routine coagulation laboratory tests such as partial thromboplastin time or prothrombin time, which are performed at standardized test temperature, after pH correction, and upon recalcification. Temperature-adjustments are feasible in viscoelastic point-of-care tests such as thrombelastography and thromboelastometry which may permit quantification of hypothermia-induced coagulopathy. Rewarming hypothermic bleeding patients is highly recommended because it improves patient outcome. Despite the absence of high-quality evidence, calcium supplementation is clinical routine in bleeding management. Buffer administration may not reverse acidosis-induced coagulopathy but may be essential for the efficacy of coagulation factor concentrates such as recombinant activated factor VII.

  16. Use of therapeutic hypothermia in cocaine-induced cardiac arrest: further evidence.

    PubMed

    Scantling, Dane; Klonoski, Emily; Valentino, Dominic J

    2014-01-01

    Therapeutic hypothermia is an important and successful treatment that has been endorsed only in specific clinical settings of cardiac arrest. Inclusion criteria thus far have not embraced drug-induced cardiac arrest, but clinical evidence has been mounting that therapeutic hypothermia may be beneficial in such cases. A 59-year-old man who experienced a cocaine-induced cardiac arrest had a full neurological recovery after use of therapeutic hypothermia. The relevant pathophysiology of cocaine-induced cardiac arrest is reviewed, the mechanism and history of therapeutic hypothermia are discussed, and the clinical evidence recommending the use of therapeutic hypothermia in cocaine-induced cardiac arrest is reinforced.

  17. Induced Hypothermia Does Not Harm Hemodynamics after Polytrauma: A Porcine Model

    PubMed Central

    Weuster, Matthias; Mommsen, Philipp; Pfeifer, Roman; Mohr, Juliane; Ruchholtz, Steffen; Flohé, Sascha; Fröhlich, Matthias; Keibl, Claudia; Seekamp, Andreas; van Griensven, Martijn; Witte, Ingo

    2015-01-01

    Background. The deterioration of hemodynamics instantly endangers the patients' life after polytrauma. As accidental hypothermia frequently occurs in polytrauma, therapeutic hypothermia still displays an ambivalent role as the impact on the cardiopulmonary function is not yet fully understood. Methods. We have previously established a porcine polytrauma model including blunt chest trauma, penetrating abdominal trauma, and hemorrhagic shock. Therapeutic hypothermia (34°C) was induced for 3 hours. We documented cardiovascular parameters and basic respiratory parameters. Pigs were euthanized after 15.5 hours. Results. Our polytrauma porcine model displayed sufficient trauma impact. Resuscitation showed adequate restoration of hemodynamics. Induced hypothermia had neither harmful nor major positive effects on the animals' hemodynamics. Though heart rate significantly decreased and mixed venous oxygen saturation significantly increased during therapeutic hypothermia. Mean arterial blood pressure, central venous pressure, pulmonary arterial pressure, and wedge pressure showed no significant differences comparing normothermic trauma and hypothermic trauma pigs during hypothermia. Conclusions. Induced hypothermia after polytrauma is feasible. No major harmful effects on hemodynamics were observed. Therapeutic hypothermia revealed hints for tissue protective impact. But the chosen length for therapeutic hypothermia was too short. Nevertheless, therapeutic hypothermia might be a useful tool for intensive care after polytrauma. Future studies should extend therapeutic hypothermia. PMID:26170533

  18. Helium-cold induced hypothermia in the white rat.

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.; Jacobs, M.

    1973-01-01

    Hypothermia was induced in white rats by exposing them to low ambient temperatures (about 0 C) and a gaseous atmosphere of 80% helium and 20% oxygen (helox). Biological survival, in which revival from hypothermia to normothermia is achieved, and clinical survival, in which one or more functional attributes are monitored in the hypothermic animal until it dies, are examined. The helium-cold method appears to produce a hypothermic state in the rat quite similar to that resulting from such techniques as ice water immersion or hypercapnia + hypoxia. There is a direct relationship between body weight and percent survival. Despite the fact that they require a longer period to become hypothermic, the heavier animals are better able to survive.

  19. Pharmacologically induced hypothermia attenuates traumatic brain injury in neonatal rats.

    PubMed

    Gu, Xiaohuan; Wei, Zheng Zachory; Espinera, Alyssa; Lee, Jin Hwan; Ji, Xiaoya; Wei, Ling; Dix, Thomas A; Yu, Shan Ping

    2015-05-01

    Neonatal brain trauma is linked to higher risks of mortality and neurological disability. The use of mild to moderate hypothermia has shown promising potential against brain injuries induced by stroke and traumatic brain injury (TBI) in various experimental models and in clinical trials. Conventional methods of physical cooling, however, are difficult to use in acute treatments and in induction of regulated hypothermia. In addition, general anesthesia is usually required to mitigate the negative effects of shivering during physical cooling. Our recent investigations demonstrate the potential therapeutic benefits of pharmacologically induced hypothermia (PIH) using the neurotensin receptor (NTR) agonist HPI201 (formerly known as ABS201) in stroke and TBI models of adult rodents. The present investigation explored the brain protective effects of HPI201 in a P14 rat pediatric model of TBI induced by controlled cortical impact. When administered via intraperitoneal (i.p.) injection, HPI201 induced dose-dependent reduction of body and brain temperature. A 6-h hypothermic treatment, providing an overall 2-3°C reduction of brain and body temperature, showed significant effect of attenuating the contusion volume versus TBI controls. Attenuation occurs whether hypothermia is initiated 15min or 2h after TBI. No shivering response was seen in HPI201-treated animals. HPI201 treatment also reduced TUNEL-positive and TUNEL/NeuN-colabeled cells in the contusion area and peri-injury regions. TBI-induced blood-brain barrier damage was attenuated by HPI201 treatment, evaluated using the Evans Blue assay. HPI201 significantly decreased MMP-9 levels and caspase-3 activation, both of which are pro-apototic, while it increased anti-apoptotic Bcl-2 gene expression in the peri-contusion region. In addition, HPI201 prevented the up-regulation of pro-inflammatory tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6. In sensorimotor activity assessments, rats in the HPI201

  20. Translating drug-induced hibernation to therapeutic hypothermia.

    PubMed

    Jinka, Tulasi R; Combs, Velva M; Drew, Kelly L

    2015-06-17

    Therapeutic hypothermia (TH) improves prognosis after cardiac arrest; however, thermoregulatory responses such as shivering complicate cooling. Hibernators exhibit a profound and safe reversible hypothermia without any cardiovascular side effects by lowering the shivering threshold at low ambient temperatures (Ta). Activation of adenosine A1 receptors (A1ARs) in the central nervous system (CNS) induces hibernation in hibernating species and a hibernation-like state in rats, principally by attenuating thermogenesis. Thus, we tested the hypothesis that targeted activation of the central A1AR combined with a lower Ta would provide a means of managing core body temperature (Tb) below 37 °C for therapeutic purposes. We targeted the A1AR within the CNS by combining systemic delivery of the A1AR agonist (6)N-cyclohexyladenosine (CHA) with 8-(p-sulfophenyl)theophylline (8-SPT), a nonspecific adenosine receptor antagonist that does not readily cross the blood-brain barrier. Results show that CHA (1 mg/kg) and 8-SPT (25 mg/kg), administered intraperitoneally every 4 h for 20 h at a Ta of 16 °C, induce and maintain the Tb between 29 and 31 °C for 24 h in both naïve rats and rats subjected to asphyxial cardiac arrest for 8 min. Faster and more stable hypothermia was achieved by continuous infusion of CHA delivered subcutaneously via minipumps. Animals subjected to cardiac arrest and cooled by CHA survived better and showed less neuronal cell death than normothermic control animals. Central A1AR activation in combination with a thermal gradient shows promise as a novel and effective pharmacological adjunct for inducing safe and reversible targeted temperature management.

  1. Induced mild hypothermia in post-cardiopulmonary bypass vasoplegia syndrome.

    PubMed

    Tripathi, Mukesh; Singh, Prabhat Kumar; Kumar, Naresh; Pant, Kailash Chandra

    2009-01-01

    The state of vasoplegia in immediate post-cardiopulmonary bypass period is characterized by severe hypotension, supranormal cardiac output, low systemic vascular resistance (SVR), and resistance to vasoconstrictors. We could successfully use induced mild hypothermia to increase SVR, and could avoid very high doses of nor-epinephrine (>0.3 mcg/kg/min) in the background of severe pulmonary hypertension (systolic pulmonary pressure> 90 mmHg). Its effects such as decreased oxygen demand, positive inotropy and better right ventricle performance probably helped to improve oxygenation in presence of pulmonary oedema.

  2. Facilitation of amphetamine-induced hypothermia in mice by GABA agonists and CCK-8.

    PubMed

    Boschi, G; Launay, N; Rips, R

    1991-04-01

    1. Amphetamine-induced hypothermia in mice is facilitated by dopaminergic stimulation and 5-hydroxytryptaminergic inhibition. The present study was designed to investigate: (a) the involvement of other neuronal systems, such as the gamma-aminobutyric acid (GABA), the opioid and the cholecystokinin (CCK-8) systems; (b) the possible contribution of hydroxylated metabolites of amphetamine to the hypothermia; (c) the capacity of dopamine itself to induce hypothermia and its mechanisms, in order to clarify the resistance of amphetamine-induced hypothermia to certain neuroleptics. 2. Pretreatment with the GABA antagonists, bicuculline and picrotoxin, did not inhibit amphetamine-induced hypothermia. The GABAB agonist, baclofen (2.5 mg kg-1, i.p.) potentiated this hypothermia, whereas the GABAA agonist, muscimol, did not. gamma-Butyrolactone (GBL) (40 mg kg-1, i.p.) and the neuropeptide CCK-8 (0.04 mg kg-1, i.p.) also induced potentiation. The opioid antagonist, naloxone, was without effect. 3. Dopamine itself (3, 9, 16 and 27 micrograms, i.c.v.) induced less hypothermia than the same doses of amphetamine. Sulpiride did not block dopamine-induced hypothermia, but pimozide (4 mg kg-1, i.p.), cis(z)flupentixol (0.25 mg kg-1, i.p.) and haloperidol (5 micrograms, i.c.v.) did. The direct dopamine receptor agonist, apomorphine, did not alter the hypothermia. Neither the 5-hydroxytryptamine (5-HT) receptor blocker, cyproheptadine, nor the inhibitor of 5-HT synthesis, p-chlorophenylalanine (PCPA), modified dopamine-induced hypothermia. Fluoxetine, an inhibitor of 5-HT reuptake, had no effect, whereas quipazine (6 mg kg-1, i.p.), a 5-HT agonist, totally prevented the hypothermia. Hypothermia was unaffected by pretreatment with CCK-8. 4. These data indicate that the hypothermia induced by amphetamine involves not only dopaminergic and 5-hydroxytryptaminergic systems which are functionally antagonistic, but is also facilitated by direct or indirect GABA and CCK-8 receptor stimulation

  3. Neurotensin analog NT77 induces regulated hypothermia in the rat.

    PubMed

    Gordon, Christopher J; McMahon, Beth; Richelson, Elliott; Padnos, Beth; Katz, Laurence

    2003-10-03

    The potential use of hypothermia as a therapeutic treatment for stroke and other pathological insults has prompted the search for drugs that can lower core temperature. Ideally, a drug is needed that reduces the set-point for control of core temperature (T(c)) and thereby induces a regulated reduction in T(c). To this end, a neurotensin analog (NT77) that crosses the blood brain barrier and induces hypothermia was assessed for its effects on the set-point for temperature regulation in the Sprague-Dawley rat by measuring behavioral and autonomic thermoregulatory responses. Following surgical implanation of radiotransmitters to monitor T(c), rats were placed in a temperature gradient and allowed to select from a range of ambient temperatures (T(a)) while T(c) was monitored by radiotelemetry. There was an abrupt decrease in selected T(a) from 29 to 16 degrees C and a concomitant reduction in T(c) from 37.4 to 34.0 degrees C 1 hr after IP injection of 5.0 mg/kg NT77. Selected T(a) and T(c) then recovered to control levels by 1.5 hr and 4 hr, respectively. Oxygen consumption (M) and heat loss (H) were measured in telemetered rats housed in a direct calorimeter maintained at a T(a) of 23.5 degrees C. Injection of NT77 initially led to a reduction in M, little change in H, and marked decrease in T(c). H initially rose but decreased around the time of the maximal decrease in T(c). Overall, NT77 appears to induce a regulated hypothermic response because the decrease in T(c) was preceded by a reduction in heat production, no change in heat loss, and preference for cold T(a)'s. Inducing a regulated hypothermic response with drugs such as NT77 may be an important therapy for ischemic disease and other insults.

  4. Moderate Hypothermia Inhibits Brain Inflammation and Attenuates Stroke-induced Immunodepression in Rats

    PubMed Central

    Gu, Li-Juan; Xiong, Xiao-Xing; Ito, Takashi; Lee, Jessica; Xu, Bao-Hui; Krams, Sheri; Steinberg, Gary K.; Zhao, Heng

    2013-01-01

    Summary Aims Stroke causes both brain inflammation and immunodepression. Mild to moderate hypothermia is known to attenuate brain inflammation but its role in stroke-induced immunodepression (SIID) of the peripheral immune system remains unknown. This study investigated the effects in rats of moderate intra-ischemic hypothermia on SIID and brain inflammation. Methods Stroke was induced in rats by permanent distal MCA occlusion combined with transient bilateral CCA occlusion while body temperature was reduced to 30°C. Real-time PCR, flow cytometry, in vitro T cell proliferation assays and confocal microscopy were used to study SIID and brain inflammation. Results Brief Intra-Ischemic hypothermia helped maintain certain leukocytes in the peripheral blood and spleen, and enhanced T cell proliferation in vitro and delayed-type hypersensitivity in vivo, suggesting that hypothermia reduces SIID. In contrast, in the brain, brief intra-Ischemic hypothermia inhibited mRNA expression of anti-inflammatory cytokine IL-10 and pro-inflammatory cytokines INF-γ, TNF-α, IL-2, IL-1β and MIP-2. Brief intra-Ischemic hypothermia also attenuated the infiltration of lymphocytes, neutrophils (MPO+ cells) and macrophages (CD68+ cells) into the ischemic brain, suggesting that hypothermia inhibited brain inflammation. Conclusions Brief intra-ischemic hypothermia attenuated SIID and protected against acute brain inflammation. PMID:23981596

  5. Ethanol-induced hypothermia and hyperglycemia in genetically obese mice

    SciTech Connect

    Haller, E.W.; Wittmers, L.E. Jr.

    1989-01-01

    Blood glucose and rectal temperatures were monitored in two strains of genetically obese mice (C57 BL/6J ob/ob) prior to and following intragastric ethanol administration in an attempt to relate the hypothermic response to ethanol to extracellular glucose concentration. In contrast to expectation, ethanol administration was typically associated with a hyperglycemia and a hypothermic response. In the ob/ob genotype, the hypothermic response was associated with pronounced hyperglycemia which was more emphatic in older animals. The data support the conclusion that ethanol-induced hypothermia is independent of blood glucose levels. In light of the known sensitivity of ob/ob mice to insulin, it is suggested further that the observed hypothermic response was not a function of the animals' ability to transport glucose into peripheral cells. The observed hyperglycemia of the obese animals was most likely stress-related

  6. Mild hypothermia reduces ventilator-induced lung injury, irrespective of reducing respiratory rate.

    PubMed

    Aslami, Hamid; Kuipers, Maria T; Beurskens, Charlotte J P; Roelofs, Joris J T H; Schultz, Marcus J; Juffermans, Nicole P

    2012-02-01

    In the era of lung-protective mechanical ventilation using limited tidal volumes, higher respiratory rates are applied to maintain adequate minute volume ventilation. However, higher respiratory rates may contribute to ventilator-induced lung injury (VILI). Induced hypothermia reduces carbon dioxide production and might allow for lower respiratory rates during mechanical ventilation. We hypothesized that hypothermia protects from VILI and investigated whether reducing respiratory rates enhance lung protection in an in vivo model of VILI. During 4 h of mechanical ventilation, VILI was induced by tidal volumes of 18 mL/kg in rats, with respiratory rates set at 15 or 10 breaths/min in combination with hypothermia (32°C) or normothermia (37°C). Hypothermia was induced by external cooling. A physiologic model was established. VILI was characterized by increased pulmonary neutrophil influx, protein leak, wet weights, histopathology score, and cytokine levels compared with lung protective mechanical ventilation. Hypothermia decreased neutrophil influx, pulmonary levels, systemic interleukin-6 levels, and histopathology score, and it tended to decrease the pulmonary protein leak. Reducing the respiratory rate in combination with hypothermia did not reduce the parameters of the lung injury. In conclusion, hypothermia protected from lung injury in a physiologic VILI model by reducing inflammation. Decreasing the respiratory rate mildly did not enhance protection.

  7. Intrathecal Opioid-Induced Hypothermia Following Subarachnoid Block With Morphine Injection for Elective Cesarean Delivery: A Case Report.

    PubMed

    Mach, John; Van Havel, Teresa; Gadwood, John; Biegner, M Andrew

    2016-02-01

    Opioids have been administered intrathecally with subarachnoid block for postoperative pain relief in parturients undergoing elective cesarean deliveries. This case report presents the uncommon occurrence of intrathecal opioid-induced hypothermia in the latent phase of recovery following elective cesarean delivery. There are few case reports on the occurrence of latent-phase postanesthesia care hypothermia in patients receiving subarachnoid block with morphine sulfate injection (Duramorph). Hypothermia can occur postoperatively for many reasons and can be life-threatening. In this case, hypothermia developed and progressed throughout the postoperative period. The causes of hypothermia were evaluated and treated without success initially. Thyroid dysfunction and alternative differential diagnoses were ruled out. Further assessment determined that the morphine injection might have been a contributing factor. Naloxone at 40-μg increments was administered intravenously and corrected the hypothermia. Awareness of hypothermia postoperatively with associated morphine administration through subarachnoid block must be ruled out in cases of progressing hypothermia.

  8. THE MUSCARINIC ANTAGONIST SCOPOLAMINE ATTENUATES CHLORPYRIFOS INDUCED HYPOTHERMIA IN THE DEVELOPING RAT.

    EPA Science Inventory

    Chlorpyrifos (CHP), an anticholinesterase organophosphate (OP) pesticide, induces acute hypothermia in adult and developing rats. Previously we demonstrated that thermoregulation in preweanling pups is markedly more sensitive to the neurotoxic effects of CHP than in adults. The c...

  9. ATP induces mild hypothermia in rats but has a strikingly detrimental impact on focal cerebral ischemia.

    PubMed

    Zhang, Meijuan; Li, Wenjin; Niu, Guangming; Leak, Rehana K; Chen, Jun; Zhang, Feng

    2013-01-01

    Ischemic stroke is a devastating condition lacking effective therapies. A promising approach to attenuate ischemic injury is mild hypothermia. Recent studies show that adenosine nucleotides can induce hypothermia in mice. The purpose of the present study was to test the hypothesis that adenosine 5'-triphosphate (ATP) induces mild hypothermia in rats and reduces ischemic brain injury. We found that intraperitoneal injections of ATP decreased core body temperature in a dose-dependent manner; the dose appropriate for mild hypothermia was 2 g/kg. When ATP-induced hypothermia was applied to stroke induced by middle cerebral artery occlusion, however, a neuroprotective effect was not observed. Instead, the infarct volume grew even larger in ATP-treated rats. This was accompanied by an increased rate of seizure events, hemorrhagic transformation, and higher mortality. Continuous monitoring of physiologic parameters revealed that ATP reduced heartbeat rate and blood pressure. ATP also increased blood glucose, accompanied by severe acidosis and hypocalcemia. Western blotting showed that ATP decreased levels of both phospho-Akt and total-Akt in the cortex. Our results reveal that, despite inducing hypothermia, ATP is not appropriate for protecting the brain against stroke. Instead, we show for the first time that ATP treatment is associated with exaggerated ischemic outcomes and dangerous systemic side effects.

  10. Accidental Hypothermia,

    DTIC Science & Technology

    1988-03-03

    on risk factors.329,538,539,303,93 Safe experimental investigations of hypothermia in hurman volunteers terminate cooling at 350C. This precludes...clinical experiments and surgically induced hypothermia. 423 a195 ,19 3 13 ,202 ,543 ,19 7 ,84 ,175 ,227 ,10 1,443 yward measured his own esophageal...the periphery and core. L9 For example, hypothermic patients experience major afterdrops when frostbitten extremities are thawed prematurely

  11. Moderate or deep local hypothermia does not prevent the onset of ischemia-induced dendritic damage

    PubMed Central

    Tran, Sherri; Chen, Shangbin; Liu, Ran R; Xie, Yicheng; Murphy, Timothy H

    2012-01-01

    We studied the acute (up to 2 hours after reperfusion) effects of localized cortical hypothermia on ischemia-induced dendritic structural damage. Moderate (31°C) and deep (22°C) hypothermia delays, but does not block the onset of dendritic blebbing or spine loss during global ischemia in mouse in vivo. Hypothermic treatment promoted more consistent recovery of dendritic structure and spines during reperfusion. These results suggest that those using therapeutic hypothermia will need to consider that it does not spare neurons from structural changes that are the result of ischemia, but hypothermia may interact with mechanisms that control the onset of damage and recovery during reperfusion. PMID:22167237

  12. Involvement of histamine H1 and H2 receptors in hypothermia induced by ionizing radiation in guinea pigs

    SciTech Connect

    Kandasamy, S.B.; Hunt, W.A.

    1988-01-01

    Radiation-induced hypothermia was examined in guinea pigs. Exposure to the head alone or whole-body irradiation induced hypothermia, whereas exposure of the body alone produced a small insignificant response. Systemic injection of disodium cromoglycate (a mast cell stabilizer) and cimetidine (H2-receptor antagonist) had no effect on radiation-induced hypothermia, whereas systemic and central administration of mepyramine (H1-receptor antagonist) or central administration of disodium cromoglycate or cimetidine attenuated it, indicating the involvement of central histamine through both H1 and H2 receptors in this response. Serotonin is not involved, since the serotonin antagonist methysergide had no effect on radiation-induced hypothermia. These results indicate that central histaminergic systems may be involved in radiation-induced hypothermia. 34 references, 5 figures, 2 tables.

  13. Involvement of histamine H1 and H2 receptors in hypothermia induced by ionizing radiation in guinea pigs

    SciTech Connect

    Kandasamy, S.B.; Hunt, W.A.

    1988-01-01

    Radiation-induced hypothermia was examined in guinea pigs. Exposure to the head alone or whole-body irradiation-induced hypothermia, whereas exposure of the body alone produced a small insignificant response. Systemic injection of disodium cromoglycate (a mast cell stabilizer) and cimetidine (H2-receptor antagonist) had no effect on radiation-induced hypothermia, whereas systemic and central administration of mepyramine (H1-receptor antagonist) or central administration disodium cromoglycate or cimetidine attenuated it, indicating the involvement of central histamine through both H1 and H2 receptors in this response. Serotonin is not involved, since the serotonin antagonist methysergide had no effect on radiation-induced hypothermia. These results indicate that central histaminergic systems may be involved in radiation-induced hypothermia.

  14. Adaptation to cold swim stress-induced hypothermia: Absence of Pavlovian conditional tolerance.

    PubMed

    Kokkinidis, L

    1986-01-01

    Mice subjected to cold swim stress developed pronounced hypothermia. Exposure to warm water swim, however, had little or no effect on body temperature. After repeated exposure to cold swim, the stress-induced hypothermia was attenuated. The finding that cold swim resulted in hypothermia, whereas warm swim had no effect in this respect, provided a useful experimental design by which to assess the role of conditioning factors in the adaptation to the thermic effects of cold swim. In two subsequent experiments, mice received cold swim either in a familiar environment or in a novel environment. Adaptation to the thermic effects of cold swim was observed when mice were tested in the distinctive environment, regardless of the environmental cues previously paired with repeated exposure to the cold swim stress. These findings suggest that contextual cues were not of primary importance in the development of tolerance to the thermic effects of cold swim stress.

  15. Capsaicin pretreatment attenuates LPS-induced hypothermia through TRPV1-independent mechanisms in chicken.

    PubMed

    Nikami, Hideki; Mahmoud, Motamed Elsayed; Shimizu, Yasutake; Shiina, Takahiko; Hirayama, Haruko; Iwami, Momoe; Dosoky, Reem Mahmoud; Ahmed, Moustafa Mohamed; Takewaki, Tadashi

    2008-06-06

    It has been demonstrated that chicken TRPV1 (transient receptor potential vanilloid of subtype-1) is insensitive to capsaicin (CAP), and therefore, a chicken model is suitable to analyze the CAP-sensitive TRPV1-independent pathway. We elucidated here the possible involvement of the pathway in hypothermia induced by bacterial endotoxin (lipopolysaccharide, LPS) in chickens. Chicks were pretreated with CAP (10 mg/kg, iv) at 1, 2 and 3 days of age to desensitize them towards the CAP-sensitive pathway. An intravenous injection of LPS in 4-day-old chicks caused progressive hypothermia, ending with collapse and 78% mortality within 12 h after injection. The CAP pretreatment rescued the LPS-induced endotoxin shock and hypothermia in chicks. LPS-induced iNOS expression as well as NO production in liver and lung was suppressed by CAP pretreatment. CAP pretreatment also attenuated hypothermia due to exposure of chicks to cold ambient temperature. These findings suggest that a CAP-sensitive TRPV1-independent pathway may be involved in pathophysiological hypothermic reactions through the mediation of NO in chickens.

  16. [Cold inducible RNA-binding protein inhibits hippocampal neuronal apoptosis under hypothermia by regulating redox system].

    PubMed

    Li, Jing-Hui; Zhang, Xue; Meng, Yu; Li, Chang-Sheng; Ji, Hong; Yang, Huan-Min; Li, Shi-Ze

    2015-08-25

    In this study, we intend to confirm our hypothesis that cold inducible RNA-binding protein (CIRP) can inhibit neuronal apoptosis through suppressing the formation of oxygen free radicals under hypothermia. Primary rat hippocampal neurons were isolated and cultured in vitro, and were divided into five groups: (1) normal control group (37 °C), (2) cells infected by empty viral vector group, (3) CIRP over-expressed group, (4) CIRP knock-down group, and (5) hypothermia control group. Cells in groups 2-5 were cultured under 32 °C, 5% CO2. Apoptosis of hippocampal neurons were detected by Annexin V-FITC/PI staining and flow cytometry; Expression of CIRP was determined by Western blot; Redox-related parameters (T-AOC, GSH-Px, SOD, MDA) were detected by ELISA kits. Results showed that CIRP expression levels were significantly increased (P < 0.01) and the apoptotic rates were significantly decreased (P < 0.01) in hypothermia control group and CIRP over-expressed group when compared with normal control group. On the other hand, the apoptotic rate was significantly increased (P < 0.05) in CIRP knock-down group compared with that in hypothermia control group. The levels of redox parameters in hypothermia control group and CIRP over-expressed group were significantly changed in comparison with those in normal control group, CIRP knock-down group and empty viral vector infected group, respectively (P < 0.05 or P < 0.01). These results suggest that up-regulation of CIRP by hypothermia treatment can protect the neuron from apoptosis through suppressing the formation of oxygen free radicals.

  17. Intravenous hydrogen sulfide does not induce hypothermia or improve survival from hemorrhagic shock in pigs.

    PubMed

    Drabek, Tomas; Kochanek, Patrick M; Stezoski, Jason; Wu, Xianren; Bayir, Hülya; Morhard, Ryan C; Stezoski, S William; Tisherman, Samuel A

    2011-01-01

    Several laboratory studies suggested that induced hypothermia during hemorrhagic shock improves survival. Inhaled hydrogen sulfide (H2S) induced hypothermia and decreased metabolism in mice and rats but not in piglets. We tested the hypothesis that i.v. H2S will induce hypothermia, reduce oxygen consumption (VO2), and improve outcome in prolonged hemorrhagic shock in pigs. We also assessed markers of organ injury (alanine aminotransferase, aspartate aminotransferase, creatine phosphokinase, creatinine, and troponin) and level of protein thiols to monitor H2S metabolism. In a prospective randomized study, pigs were subjected to volume-controlled hemorrhagic shock with limited fluid resuscitation to maintain MAP 30 mmHg or greater. The study group received infusion of H2S at 5 mg·kg·h; the control group received vehicle (n = 8 per group). Dose was based on the highest tolerated dose in pilot studies. Full resuscitation was initiated after 3 h. There were no differences in survival at 24 h between groups (2/8 in H2S vs. 3/8 in control group). Heart rate increased similarly during hemorrhagic shock in both groups. Cardiac output was better preserved in the delayed phase of hemorrhagic shock in the control group. Temperature and VO2 were similar in both groups during hemorrhagic shock and resuscitation. Markers of organ injury and protein thiols markedly increased in both groups with no differences between groups. In conclusion, we were not able to demonstrate the hypothermia-inducing effect or a reduction in VO2 from H2S infusion in our model of hemorrhagic shock in pigs. Our data mirror those seen in piglets and provide additional evidence of difficulty in translating the hypothermia effect of H2S to large animals in a clinically relevant postinsult paradigm.

  18. Systemic Administration of the TRPV3 Ion Channel Agonist Carvacrol Induces Hypothermia in Conscious Rodents

    PubMed Central

    Feketa, Viktor V.; Marrelli, Sean P.

    2015-01-01

    Therapeutic hypothermia is a promising new strategy for neuroprotection. However, the methods for safe and effective hypothermia induction in conscious patients are lacking. The current study explored the Transient Receptor Potential Vanilloid 3 (TRPV3) channel activation by the agonist carvacrol as a potential hypothermic strategy. It was found that carvacrol lowers core temperature after intraperitoneal and intravenous administration in mice and rats. However, the hypothermic effect at safe doses was modest, while higher intravenous doses of carvacrol induced a pronounced drop in blood pressure and substantial toxicity. Experiments on the mechanism of the hypothermic effect in mice revealed that it was associated with a decrease in whole-body heat generation, but not with a change in cold-seeking behaviors. In addition, the hypothermic effect was lost at cold ambient temperature. Our findings suggest that although TRPV3 agonism induces hypothermia in rodents, it may have a limited potential as a novel pharmacological method for induction of hypothermia in conscious patients due to suboptimal effectiveness and high toxicity. PMID:26528923

  19. Neuroprotective effects of hypothermia on synaptic actin cytoskeletal changes induced by perinatal asphyxia.

    PubMed

    Muñiz, Javier; Romero, Juan; Holubiec, Mariana; Barreto, George; González, Janneth; Saint-Martin, Madeleine; Blanco, Eduardo; Carlos Cavicchia, Juan; Castilla, Rocío; Capani, Francisco

    2014-05-14

    Cerebral hypoxia-ischemia damages synaptic proteins, resulting in cytoskeletal alterations, protein aggregation and neuronal death. In the previous works, we have shown neuronal and synaptic changes in rat neostriatum subjected to hypoxia that leads to ubi-protein accumulation. Recently, we also showed that, changes in F-actin organization could be related to early alterations induced by hypoxia in the Central Nervous System. However, little is known about effective treatment to diminish the damage. The main aim of this work is to study the effects of birth hypothermia on the actin cytoskeleton of neostriatal post-synaptic densities (PSD) in 60 days olds rats by immunohistochemistry, photooxidation and western blot. We used 2 different protocols of hypothermia: (a) intrahypoxic hypothermia at 15°C and (b) post-hypoxia hypothermia at 32°C. Consistent with previous data at 30 days, staining with phalloidin-Alexa(488) followed by confocal microscopy analysis showed an increase of F-actin fluorescent staining in the neostriatum of hypoxic animals. Correlative photooxidation electron microscopy confirmed these observations showing an increment in the number of mushroom-shaped F-actin staining spines in neostriatal excitatory synapses in rats subjected to hypoxia. In addition, western blot revealed β-actin increase in PSDs in hypoxic animals. The optic relative density measurement showed a significant difference between controls and hypoxic animals. When hypoxia was induced under hypothermic conditions, the changes observed in actin cytoskeleton were blocked. Post-hypoxic hypothermia showed similar answer but actin cytoskeleton modifications were not totally reverted as we observed at 15°C. These data suggest that the decrease of the body temperature decreases the actin modifications in dendritic spines preventing the neuronal death.

  20. Opposite effects of WR-2721 and WR-1065 on radiation-induced hypothermia: possible correlation with oxygen uptake. Scientific report

    SciTech Connect

    Kandasamy, S.B.; Kumar, K.S.; Hunt, W.A.; Weiss, J.F.

    1988-01-01

    Ionizing radiation induces hypothermia in guinea pigs. While systemic injection of the radioprotectant S-2-(3-aminopropylamimo)ethylphosphorothioic acid (WR-2721) did not block hypothermia induced by exposure to 10 Gy of gamma radiation, central administration did attenuate it. The dephosphorylated metabolite of WR-2721, N-(2-mercaptoethyl)-1,3-diaminopropane (WR-1065), accentuated radiation-induced hypothermia by both routes of administration. In brain homogenates, oxygen uptake was inhibited by WR-2721 but elevated by WR-1065. These results suggest that the antagonism of radiation-induced hypothermia found only after central administration of WR-2721 is due to its direct actions and not in its dephosphorylated metabolite, and that this effect may be correlated with the inhibition by WR-2721 of oxygen uptake.

  1. Cardiac hypertrophy in chick embryos induced by hypothermia

    SciTech Connect

    Boehm, C.; Johnson, T.R.; Caston, J.D.; Przybylski, R.J.

    1987-01-01

    A decrease in incubation temperature from 38 to 32/sup 0/C elicits a decrease in chicken embryo size and weight with concomitant heart enlargement if done after day 10 of incubation. When assayed at day 18 of incubation with the hypothermia started on day 11 or 14, evidence is presented that the heart enlargement is an hypertrophy with no detectable hyperplasia. Supporting data are presented for various physical parameters showing increases in heart wet and dry weight, volume, area, wall thickness, and cell size. There was little difference in DNA content and nuclear (/sup 3/H)thymidine labeling index between hearts of control and hypothermic embryos. Hearts of hypothermic embryos showed a slight increase in water content and considerable increases in RNA, protein, and glycogen content per unit DNA. The average size of polysomes isolated from hypothermic hearts was larger than that of polysomes isolated from controls. Microscopic studies showed no obvious increase in amount of capillary beds, connective tissue, and myocardial cells. Annulate lamellae were found only in myocardial cells of hypothermic embryos in sparse amounts and low frequency but always associated with large deposits of glycogen.

  2. A novel stroke therapy of pharmacologically induced hypothermia after focal cerebral ischemia in mice

    PubMed Central

    Choi, Ko-Eun; Hall, Casey L.; Sun, Jin-Mei; Wei, Ling; Mohamad, Osama; Dix, Thomas A.; Yu, Shan P.

    2012-01-01

    Compelling evidence from preclinical and clinical studies has shown that mild to moderate hypothermia is neuroprotective against ischemic stroke. Clinical applications of hypothermia therapy, however, have been hindered by current methods of physical cooling, which is generally inefficient and impractical in clinical situations. In this report, we demonstrate the potential of pharmacologically induced hypothermia (PIH) by the novel neurotensin receptor 1 (NTR1) agonist ABS-201 in a focal ischemic model of adult mice. ABS-201 (1.5–2.5 mg/kg, i.p.) reduces body and brain temperature by 2–5°C in 15–30 min in a dose-dependent manner without causing shivering or altering physiological parameters. Infarct volumes at 24 h after stroke are reduced by ∼30–40% when PIH therapy is initiated either immediately after stroke induction or after 30–60 min delay. ABS-201 treatment increases bcl-2 expression, decreases caspase-3 activation, and TUNEL-positive cells in the peri-infarct region, and suppresses autophagic cell death compared to stroke controls. The PIH therapy using ABS-201 improves recovery of sensorimotor function as tested 21 d after stroke. These results suggest that PIH induced by neurotensin analogs represented by ABS-201 are promising candidates for treatment of ischemic stroke and possibly for other ischemic or traumatic injuries. Choi, K.-E., Hall, C. L., Sun, J.-M., Wei, L., Mohamad, O., Dix, T. A., Yu, S. P. A novel stroke therapy of pharmacologically induced hypothermia after focal cerebral ischemia in mice. PMID:22459147

  3. Hypothermia in trauma.

    PubMed

    Moffatt, Samuel Edwin

    2013-12-01

    Hypovolaemic shock that results through traumatically inflicted haemorrhage can have disastrous consequences for the victim. Initially the body can compensate for lost circulating volume, but as haemorrhage continues compensatory mechanisms fail and the patient's condition worsens significantly. Hypovolaemia results in the lethal triad, a combination of hypothermia, acidosis and coagulopathy, three factors that are interlinked and serve to worsen each other. The lethal triad is a form of vicious cycle, which unless broken will result in death. This report will focus on the role of hypothermia (a third of the lethal triad) in trauma, examining literature to assess how prehospital temperature control can impact on the trauma patient. Spontaneous hypothermia following trauma has severely deleterious consequences for the trauma victim; however, both active warming of patients and clinically induced hypothermia can produce particularly positive results and improve patient outcome. Possible coagulopathic side effects of clinically induced hypothermia may be corrected with topical haemostatic agents, with the benefits of an extended golden hour given by clinically induced hypothermia far outweighing these risks. Active warming of patients, to prevent spontaneous trauma induced hypothermia, is currently the only viable method currently available to improve patient outcome. This method is easy to implement requiring simple protocols and contributes significantly to interrupting the lethal triad. However, the future of trauma care appears to lie with clinically induced therapeutic hypothermia. This new treatment provides optimism that in the future the number of deaths resulting from catastrophic haemorrhaging may be significantly lessened.

  4. Ketogenic diet and fasting induce the expression of cold-inducible RNA-binding protein with time-dependent hypothermia in the mouse liver.

    PubMed

    Oishi, Katsutaka; Yamamoto, Saori; Uchida, Daisuke; Doi, Ryosuke

    2013-01-01

    Cold-inducible RNA-binding protein (CIRBP) induced by cold stress modulates the molecular circadian clock in vitro. The present study examines the effect of a ketogenic diet (KD) and fasting on Cirbp expression in the mouse liver. Chronic KD administration induced time-dependent Cirbp expression with hypothermia in mice. The circadian expression of clock genes such as Bmal1 and Clock was phase-advanced and augmented in the liver of mice fed with a KD. Transient food deprivation also induced time-dependent Cirbp expression with hypothermia in mice. These findings suggest that hypothermia is involved in the increased expression of Cirbp under ketogenic or fasting conditions.

  5. Hypothermia induced by adenosine 5'-monophosphate attenuates early stage injury in an acute gouty arthritis rat model.

    PubMed

    Miao, Zhimin; Guo, Weiting; Lu, Shulai; Lv, Wenshan; Li, Changgui; Wang, Yangang; Zhao, Shihua; Yan, Shengli; Tao, Zhenyin; Wang, Yunlong

    2013-08-01

    To investigate whether the hypothermia induced by Adenosine 5'-Monophosphate (5'-AMP) could attenuate early stage injury in a rat acute gouty arthritis model. Ankle joint injection with monosodium urate monohydrate crystals (MSU crystals) in hypothermia rat model which was induced by 5'-AMP and then observe whether hypothermia induced by 5'-AMP could be effectively inhibit the inflammation on acute gouty arthritis in rats. AMP-induced hypothermia has protective effects on our acute gouty arthritis, which was demonstrated by the following criteria: (1) a significant reduction in the ankle swelling (p < 0.001); (2) a significant decrease in the occurrence of leukocyte infiltration and mild hemorrhage; (3) a significant reduction in the presence of serum Interleukin-1β (IL-1β, p < 0.001) and metalloproteinase-9 (MMP-9, p < 0.001); and (4) a significant inhibition in the Nuclear Factor -κappaB (NF-κB) activity (p < 0.001). AMP-induced hypothermia could inhibit acute inflammation reaction and protect the synovial tissue against acute injury in a rat acute gouty arthritis model.

  6. Opposite effects of WR-2721 and WR-1065 on radiation-induced hypothermia: possible correlation with oxygen uptake

    SciTech Connect

    Kandasamy, S.B.; Kumar, K.S.; Hunt, W.A.; Weiss, J.F.

    1988-05-01

    Ionizing radiation induces hypothermia in guinea pigs. While systemic injection of the radioprotectant S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721) did not block hyperthermia induced by exposure to 10 Gy of gamma radiation, central administration did attenuate it. The dephosphorylated metabolite of WR-2721, N-(2-mercaptoethyl)-1,3-diaminopropane (WR-1065), accentuated radiation-induced hypothermia by both routes of administration. In brain homogenates, oxygen uptake was inhibited by WR-2721 but elevated by WR-1065. These results suggest that the antagonism of radiation-induced hypothermia found only after central administration of WR-2721 is due to its direct actions and not to its dephosphorylated metabolite and that this effect may be correlated with the inhibition by WR-2721 of oxygen uptake.

  7. Tyrosine Pretreatment Reverses Hypothermia-Induced Behavioral Depression

    DTIC Science & Technology

    1990-01-01

    behavioral depression induced by forced swimming in 21- Tyrosine significantly decreased immobility in the swim test 25C water, in a restricted space...Figure 2 shows the effect of tyrosine on immobility in the swim observed that tle behavioral inactivity and the reduction of brain test . A post hoc...Gibson. C. J.; Wurtman, R. J. Physiological control of brain Immobility induced by forced swimming ,n rats: Effects of agents norepinephrine synthesis by

  8. Hypoxia-induced hypothermia mediated by GABA in the rostral parapyramidal area of the medulla oblongata.

    PubMed

    Osaka, T

    2014-05-16

    Hypoxia evokes a regulated decrease in the body core temperature (Tc) in a variety of animals. The neuronal mechanisms of this response include, at least in part, glutamatergic activation in the lateral preoptic area (LPO) of the hypothalamus. As the sympathetic premotor neurons in the medulla oblongata constitute a cardinal relay station in the descending neuronal pathway from the hypothalamus for thermoregulation, their inhibition can also be critically involved in the mechanisms of the hypoxia-induced hypothermia. Here, I examined the hypothesis that hypoxia-induced hypothermia is mediated by glutamate-responsive neurons in the LPO that activate GABAergic transmission in the rostral raphe pallidus (rRPa) and neighboring parapyramidal region (PPy) of the medulla oblongata in urethane-chloralose-anesthetized, neuromuscularly blocked, artificially ventilated rats. Unilateral microinjection of GABA (15nmol) into the rRPa and PPy regions elicited a prompt increase in tail skin temperature (Ts) and decreases in Tc, oxygen consumption rate (VO2), and heart rate. Next, when the GABAA receptor blocker bicuculline methiodide (bicuculline methiodide (BMI), 10pmol) alone was microinjected into the rRPa, it elicited unexpected contradictory responses: simultaneous increases in Ts, VO2 and heart rate and a decrease in Tc. Then, when BMI was microinjected bilaterally into the PPy, no direct effect on Ts was seen; and thermogenic and tachycardic responses were slight. However, pretreatment of the PPy with BMI, but not vehicle saline, greatly attenuated the hypothermic responses evoked by hypoxic (10%O2-90%N2, 5min) ventilation or bilateral microinjections of glutamate (5nmol, each side) into the LPO. The results suggest that hypoxia-induced hypothermia was mediated, at least in part, by the activation of GABAA receptors in the PPy.

  9. Neuroprotective effects of bloodletting at Jing points combined with mild induced hypothermia in acute severe traumatic brain injury

    PubMed Central

    Tu, Yue; Miao, Xiao-mei; Yi, Tai-long; Chen, Xu-yi; Sun, Hong-tao; Cheng, Shi-xiang; Zhang, Sai

    2016-01-01

    Bloodletting at Jing points has been used to treat coma in traditional Chinese medicine. Mild induced hypothermia has also been shown to have neuroprotective effects. However, the therapeutic effects of bloodletting at Jing points and mild induced hypothermia alone are limited. Therefore, we investigated whether combined treatment might have clinical effectiveness for the treatment of acute severe traumatic brain injury. Using a rat model of traumatic brain injury, combined treatment substantially alleviated cerebral edema and blood-brain barrier dysfunction. Furthermore, neurological function was ameliorated, and cellular necrosis and the inflammatory response were lessened. These findings suggest that the combined effects of bloodletting at Jing points (20 μL, twice a day, for 2 days) and mild induced hypothermia (6 hours) are better than their individual effects alone. Their combined application may have marked neuroprotective effects in the clinical treatment of acute severe traumatic brain injury. PMID:27482221

  10. Naturally occurring hypothermia is more advantageous than fever in severe forms of lipopolysaccharide- and Escherichia coli-induced systemic inflammation

    PubMed Central

    Liu, Elaine; Lewis, Kevin; Al-Saffar, Hiba; Krall, Catherine M.; Singh, Anju; Kulchitsky, Vladimir A.; Corrigan, Joshua J.; Simons, Christopher T.; Petersen, Scott R.; Musteata, Florin M.; Bakshi, Chandra S.; Romanovsky, Andrej A.; Sellati, Timothy J.

    2012-01-01

    The natural switch from fever to hypothermia observed in the most severe cases of systemic inflammation is a phenomenon that continues to puzzle clinicians and scientists. The present study was the first to evaluate in direct experiments how the development of hypothermia vs. fever during severe forms of systemic inflammation impacts the pathophysiology of this malady and mortality rates in rats. Following administration of bacterial lipopolysaccharide (LPS; 5 or 18 mg/kg) or of a clinical Escherichia coli isolate (5 × 109 or 1 × 1010 CFU/kg), hypothermia developed in rats exposed to a mildly cool environment, but not in rats exposed to a warm environment; only fever was revealed in the warm environment. Development of hypothermia instead of fever suppressed endotoxemia in E. coli-infected rats, but not in LPS-injected rats. The infiltration of the lungs by neutrophils was similarly suppressed in E. coli-infected rats of the hypothermic group. These potentially beneficial effects came with costs, as hypothermia increased bacterial burden in the liver. Furthermore, the hypotensive responses to LPS or E. coli were exaggerated in rats of the hypothermic group. This exaggeration, however, occurred independently of changes in inflammatory cytokines and prostaglandins. Despite possible costs, development of hypothermia lessened abdominal organ dysfunction and reduced overall mortality rates in both the E. coli and LPS models. By demonstrating that naturally occurring hypothermia is more advantageous than fever in severe forms of aseptic (LPS-induced) or septic (E. coli-induced) systemic inflammation, this study provides new grounds for the management of this deadly condition. PMID:22513748

  11. Processed aconite root prevents cold-stress-induced hypothermia and immuno-suppression in mice.

    PubMed

    Makino, Toshiaki; Kato, Keita; Mizukami, Hajime

    2009-10-01

    Processed aconite root (PA) is a crude drug used in traditional Chinese or Japanese medicine to generate heat in interior body and dispel cold. We evaluated the effects of PA on hypothermia and reduction in the activity of natural killer (NK) cells in mice exposed to chronic cold stress. Male mice were reared at 4 degrees C, and powdered PA was administered for 10 d as a food additive. Core body temperature of mice significantly decreased by approximately 1 degrees C after rearing in a cold environment, and PA administration significantly restored the reduction in core body temperature in a dose-dependent manner. After 10 d, splenic NK-cell activity of cold-stressed mice was significantly reduced, and the reduction was dose-dependently recovered by PA administration. An aconitine-type alkaloid fraction prepared from PA was ineffective when administered to cold-stressed mice, and the thermogenic effect on hypothermic mice was present in the fraction containing low-molecular-weight compounds without alkaloids. In cold-stressed mice, the weight of brown adipose tissue (BAT) and uncoupling protein (UCP)-1 level in BAT increased, whereas the weight of white adipose tissue decreased. The increase in UCP-1 level in BAT of cold-stressed mice was further augmented by PA treatment. These results indicate that PA exhibited a thermogenic effect on hypothermia induced by cold stress in mice by additional upregulation of UCP-1 level in BAT, which was already enhanced by hypothermia, and that the active ingredients present in PA are non-alkaloidal low-molecular-weight compounds.

  12. Effects of acute low-level microwaves on pentobarbital-induced hypothermia depend on exposure orientation

    SciTech Connect

    Lai, H.; Horita, A.; Chou, C.K.; Guy, A.W.

    1984-01-01

    Two series of experiments were performed to study the effects of acute exposure (45 min) to 2,450-MHz circularly polarized, pulsed microwaves (1 mW/cm2, 2-mus pulses, 500 pps, specific absorption rate (SAR) 0.6 W/kg) on the actions of pentobarbital in the rat. In the first experiment, rats were irradiated with microwaves and then immediately injected with pentobarbital. Microwave exposure did not significantly affect the extent of the pentobarbital-induced fall in colonic temperature. However, the rate of recovery from the hypothermia was significantly slower in the microwave-irradiated rats and they also took a significantly longer time to regain their righting reflex. In a second experiment, rats were first anesthetized with pentobarbital and then exposed to microwaves with their heads either pointing toward the source of microwaves (anterior exposure) or pointing away (posterior exposure). Microwave radiation significantly retarded the pentobarbital-induced fall in colonic temperature regardless of the orientation of exposure. However, the recovery from hypothermia was significantly faster in posterior-exposed animals compared to those of the anterior-exposed and sham-irradiated animals. Furthermore, the posterior-exposed rats took a significantly shorter time to regain their righting reflex than both the anterior-exposed and sham-irradiated animals.

  13. Involvement of α₂-adrenoceptors, imidazoline, and endothelin-A receptors in the effect of agmatine on morphine and oxycodone-induced hypothermia in mice.

    PubMed

    Bhalla, Shaifali; Andurkar, Shridhar V; Gulati, Anil

    2013-10-01

    Potentiation of opioid analgesia by endothelin-A (ET(A)) receptor antagonist, BMS182874, and imidazoline receptor/α₂-adrenoceptor agonists such as clonidine and agmatine are well known. It is also known that agmatine blocks morphine hyperthermia in rats. However, the effect of agmatine on morphine or oxycodone hypothermia in mice is unknown. The present study was carried out to study the role of α₂-adrenoceptors, imidazoline, and ET(A) receptors in morphine and oxycodone hypothermia in mice. Body temperature was determined over 6 h in male Swiss Webster mice treated with morphine, oxycodone, agmatine, and combination of agmatine with morphine or oxycodone. Yohimbine, idazoxan, and BMS182874 were used to determine involvement of α₂-adrenoceptors, imidazoline, and ET(A) receptors, respectively. Morphine and oxycodone produced significant hypothermia that was not affected by α₂-adrenoceptor antagonist yohimbine, imidazoline receptor/α₂ adrenoceptor antagonist idazoxan, or ET(A) receptor antagonist, BMS182874. Agmatine did not produce hypothermia; however, it blocked oxycodone but not morphine-induced hypothermia. Agmatine-induced blockade of oxycodone hypothermia was inhibited by idazoxan and yohimbine. The blockade by idazoxan was more pronounced compared with yohimbine. Combined administration of BMS182874 and agmatine did not produce changes in body temperature in mice. However, when BMS182874 was administered along with agmatine and oxycodone, it blocked agmatine-induced reversal of oxycodone hypothermia. This is the first report demonstrating that agmatine does not affect morphine hypothermia in mice, but reverses oxycodone hypothermia. Imidazoline receptors and α₂-adrenoceptors are involved in agmatine-induced reversal of oxycodone hypothermia. Our findings also suggest that ET(A) receptors may be involved in blockade of oxycodone hypothermia by agmatine.

  14. An unusual autopsy case of lethal hypothermia exacerbated by body lice-induced severe anemia.

    PubMed

    Nara, Akina; Nagai, Hisashi; Yamaguchi, Rutsuko; Makino, Yohsuke; Chiba, Fumiko; Yoshida, Ken-ichi; Yajima, Daisuke; Iwase, Hirotaro

    2016-05-01

    Pediculus humanus humanus (known as body lice) are commonly found in the folds of clothes, and can cause skin disorders when they feed on human blood, resulting in an itching sensation. Body lice are known as vectors of infectious diseases, including typhus, recurrent fever, and trench fever. An infestation with blood-sucking body lice induces severe cutaneous pruritus, and this skin disorder is known as "vagabond's disease." A body lice infestation is sometimes complicated with iron deficiency anemia. In the present case, a man in his late 70s died of lethal hypothermia in the outdoors during the winter season. The case history and autopsy findings revealed that the cause of the lethal hypothermia was iron deficiency anemia, which was associated with a prolonged infestation of blood-sucking body lice. Also, he had vagabond's disease because the skin on his body was abnormal and highly pigmented. This is an unusual autopsy case since the body lice contributed to the cause of the death.

  15. Lipopolysaccharide-induced hypothermia and hypotension are associated with inflammatory signaling that is triggered outside the brain.

    PubMed

    Al-Saffar, Hiba; Lewis, Kevin; Liu, Elaine; Schober, Alexandra; Corrigan, Joshua J; Shibata, Keita; Steiner, Alexandre A

    2013-02-01

    Little is known about the neuroimmune mechanisms responsible for the switch from fever to hypothermia observed in severe forms of systemic inflammation. We evaluated whether bacterial lipopolysaccharide (LPS) acting directly on the brain could promote a fever-hypothermia switch as well as the hypotension that is often associated with hypothermia in models of systemic inflammation. At an ambient temperature of 22°C, freely moving rats received intracerebroventricular (i.c.v.) injections of LPS at doses ranging from 0.5 to 25μg. Despite the use of such high doses, the prevailing thermal response was fever. To investigate if a hypothermic response could be hidden within the prevailing febrile response, rats were pretreated with a cyclooxygenase-2 inhibitor (SC-236, 3.5mg/kg i.v.) known to block fever, but this strategy also failed to reveal any consistent hypothermic response following i.c.v. LPS. At the doses tested, i.c.v. LPS was similarly ineffective at inducing hypotension. Additional doses of LPS did not need to be tested because the 25-μg dose was already sufficient to induce both hypothermia and hypotension when administered peripherally (intra-arterially). An empirical 3D model of the interplay among body temperature, arterial pressure and heart rate following intra-arterial LPS reinforced the strong association of hypothermia with hypotension and, at the same time, exposed a bell-shaped relationship between heart rate and body temperature. In summary, the present study demonstrates that hypothermia and hypotension are triggered exclusively by LPS acting outside the brain and provides an integrated model of the thermal and cardiovascular responses to peripheral LPS.

  16. Pharmacologically induced hypothermia via TRPV1 channel agonism provides neuroprotection following ischemic stroke when initiated 90 min after reperfusion.

    PubMed

    Cao, Zhijuan; Balasubramanian, Adithya; Marrelli, Sean P

    2014-01-15

    Traditional methods of therapeutic hypothermia show promise for neuroprotection against cerebral ischemia-reperfusion (I/R), however, with limitations. We examined effectiveness and specificity of pharmacological hypothermia (PH) by transient receptor potential vanilloid 1 (TRPV1) channel agonism in the treatment of focal cerebral I/R. Core temperature (T(core)) was measured after subcutaneous infusion of TRPV1 agonist dihydrocapsaicin (DHC) in conscious C57BL/6 WT and TRPV1 knockout (KO) mice. Acute measurements of heart rate (HR), mean arterial pressure (MAP), and cerebral perfusion were measured before and after DHC treatment. Focal cerebral I/R (1 h ischemia + 24 h reperfusion) was induced by distal middle cerebral artery occlusion. Hypothermia (>8 h) was initiated 90 min after start of reperfusion by DHC infusion (osmotic pump). Neurofunction (behavioral testing) and infarct volume (TTC staining) were measured at 24 h. DHC (1.25 mg/kg) produced a stable drop in T(core) (33°C) in naive and I/R mouse models but not in TRPV1 KO mice. DHC (1.25 mg/kg) had no measurable effect on HR and cerebral perfusion but produced a slight transient drop in MAP (<6 mmHg). In stroke mice, DHC infusion produced hypothermia, decreased infarct volume by 87%, and improved neurofunctional score. The hypothermic and neuroprotective effects of DHC were absent in TRPV1 KO mice or mice maintained normothermic with heat support. PH via TRPV1 agonist appears to be a well-tolerated and effective method for promoting mild hypothermia in the conscious mouse. Furthermore, TRPV1 agonism produces effective hypothermia in I/R mice and significantly improves outcome when initiated 90 min after start of reperfusion.

  17. Evidence for a caudal brainstem site of action for cannabinoid induced hypothermia.

    PubMed

    Hosko, M J; Schmeling, W T; Hardman, H F

    1981-03-01

    delta 9-Tetrahydrocannabinol (THC), 11-hydroxy delta 9-tetrahydrocannabinol (11-OH-THC) and the synthetic dimethylheptyl analogue of THC (DMHP) were injected intracerebrally into proven chemosensitive sites in the hypothalamus of unanesthetized cats with implanted microinjection guide tubes. 100 micrograms of each compound was administered in a volume of 8 microliters. Chemosensitivity of all injection sites was established by microinjection of carbamylcholine to induce hyperthermia and tetrodotoxin to induce hypothermia. THC or its analogues produced no significant change in body temperature when injected intracerebrally. However, in the same animals, parenteral administration of THC, 11-OH-THC or DMHP (0.5 to 2.0 mg/kg) induced hypothermic responses ranging from -2.0 to -7.0 degrees C. Intravenous administration of THC was effective in blocking shivering induced by cooling the preoptic region in unanesthetized cats with implanted thermodes. In cats with mid-pontine transections, cooling of the spinal cord by perfusion with an epidural double wall cannula at temperatures of 30, 20, 10 and 0 degrees C produced graded shivering which was recorded electromyographically. Intravenous THC, (0.25-2.0 mg/kg) produced a dose-dependent attenuation of spinal cord induced shivering. These data plus results of prior studies suggest that the tetrahydrocannabinols produce their hypothermic effect at sites in the caudal brainstem. Suppression of shivering at the ponto medullary or spinal cord level may represent an important mechanism which contributes to the lowering of body temperature.

  18. Induced hypothermia during resuscitation from hemorrhagic shock attenuates microvascular inflammation in the rat mesenteric microcirculation.

    PubMed

    Coyan, Garrett N; Moncure, Michael; Thomas, James H; Wood, John G

    2014-12-01

    Microvascular inflammation occurs during resuscitation following hemorrhagic shock, causing multiple organ dysfunction and mortality. Preclinical evidence suggests that hypothermia may have some benefit in selected patients by decreasing this inflammation, but this effect has not been extensively studied. Intravital microscopy was used to visualize mesenteric venules of anesthetized rats in real time to evaluate leukocyte adherence and mast cell degranulation. Animals were randomly allocated to normotensive or hypotensive groups and further subdivided into hypothermic and normothermic resuscitation (n = 6 per group). Animals in the shock groups underwent mean arterial blood pressure reduction to 40 to 45 mmHg for 1 h via blood withdrawal. During the first 2 h following resuscitation by infusion of shed blood plus double that volume of normal saline, rectal temperature of the hypothermic groups was maintained at 32°C to 34°C, whereas the normothermic groups were maintained between 36°C to 38°C. The hypothermic group was then rewarmed for the final 2 h of resuscitation. Leukocyte adherence was significantly lower after 2 h of hypothermic resuscitation compared with normothermic resuscitation: (2.8 ± 0.8 vs. 8.3 ± 1.3 adherent leukocytes, P = 0.004). Following rewarming, leukocyte adherence remained significantly different between hypothermic and normothermic shock groups: (4.7 ± 1.2 vs. 9.5 ± 1.6 adherent leukocytes, P = 0.038). Mast cell degranulation index (MDI) was significantly decreased in the hypothermic (1.02 ± 0.04 MDI) versus normothermic (1.22 ± 0.07 MDI) shock groups (P = 0.038) after the experiment. Induced hypothermia during resuscitation following hemorrhagic shock attenuates microvascular inflammation in rat mesentery. Furthermore, this decrease in inflammation is carried over after rewarming takes place.

  19. Pramipexole-Induced Hypothermia Reduces Early Brain Injury via PI3K/AKT/GSK3β pathway in Subarachnoid Hemorrhage rats

    PubMed Central

    Ma, Junwei; Wang, Zhong; Liu, Chenglin; Shen, Haitao; Chen, Zhouqing; Yin, Jia; Zuo, Gang; Duan, Xiaochun; Li, Haiying; Chen, Gang

    2016-01-01

    Previous studies have shown neuroprotective effects of hypothermia. However, its effects on subarachnoid hemorrhage (SAH)-induced early brain injury (EBI) remain unclear. In this study, a SAH rat model was employed to study the effects and mechanisms of pramipexole-induced hypothermia on EBI after SAH. Dose-response experiments were performed to select the appropriate pramipexole concentration and frequency of administration for induction of mild hypothermia (33–36 °C). Western blot, neurobehavioral evaluation, Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and Fluoro-Jade B (FJB) staining were used to detect the effects of pramipexole-induced hypothermia on SAH-induced EBI, as well as to study whether controlled rewarming could attenuate these effects. Inhibitors targeting the PI3K/AKT/GSK3β pathway were administered to determine whether the neuroprotective effect of pramipexole-induced hypothermia was mediated by PI3K/AKT/GSK3β signaling pathway. The results showed that intraperitoneal injection of pramipexole at 0.25 mg/kg body weight once per 8 hours was found to successfully and safely maintain rats at mild hypothermia. Pramipexole-induced hypothermia ameliorated SAH-induced brain cell death, blood-brain barrier damage and neurobehavioral deficits in a PI3K/AKT/GSK3β signaling-dependent manner. Therefore, we may conclude that pramipexole-induced hypothermia could effectively inhibit EBI after SAH in rats via PI3K/AKT/GSK3β signaling pathway. PMID:27026509

  20. Microwave attenuation of ethanol-induced hypothermia: ethanol tolerance, time course, exposure duration, and dose response studies

    SciTech Connect

    Hjeresen, D.L.; Francendese, A.; O'Donnell, J.M.

    1988-01-01

    Four experiments were conducted to quantify the reported attenuation by microwave (MW) irradiation of ethanol-induced hypothermia. In one experiment rats were irradiated (continuous wave 2.45 GHz, specific absorption rate = 0.3 W/kg) or sham irradiated for 45 min, injected with 3.6 g/kg, 20% (v/v) ethanol (EtOH) or saline (NaCl) i.p.. Colonic temperature was monitored at 20-min intervals for 2 h. This procedure was repeated for 8 days to determine the rate of tolerance development to the hypothermic effect of ethanol. While MW irradiation did significantly attenuate EtOH-induced hypothermia, it did not enhance or retard the rate of tolerance development. To determine the duration of irradiation necessary to attenuate EtOH-induced hypothermia, groups of rats were irradiated or sham irradiated for 5, 15, 30, or 60 min prior to EtOH injection and subsequent temperature measurements. The attenuation was apparent only after 60 min of irradiation. To determine the duration of the attenuation effect after irradiation, rats were injected with EtOH or NaCl at 0, 30, 60, 120, or 480 min after 45 min of irradiation or sham irradiation. The attenuation effect was apparent among rats injected 0 to 30 min after irradiation and for the first 40 min for groups injected at 120 min. Additional rats were injected with NaCl or 0.9, 1.8, or 2.7 g/kg of EtOH i.p. following 45 min of irradiation or sham irradiation to determine if the attenuation effect depends on the dose of EtOH administered. Attenuation of EtOH-induced hypothermia was more apparent at lower doses of EtOH than at higher doses. These results indicate that the effect is an acute response to irradiation, and rule out several other potential explanations.

  1. Electrocardiographic changes during induced therapeutic hypothermia in comatose survivors after cardiac arrest

    PubMed Central

    Salinas, Pablo; Lopez-de-Sa, Esteban; Pena-Conde, Laura; Viana-Tejedor, Ana; Rey-Blas, Juan Ramon; Armada, Eduardo; Lopez-Sendon, Jose Luis

    2015-01-01

    AIM: To assess the safety of therapeutic hypothermia (TH) concerning arrhythmias we analyzed serial electrocardiograms (ECG) during TH. METHODS: All patients recovered from a cardiac arrest with Glasgow < 9 at admission were treated with induced mild TH to 32-34 °C. TH was obtained with cool fluid infusion or a specific intravascular device. Twelve-lead ECG before, during, and after TH, as well as ECG telemetry data was recorded in all patients. From a total of 54 patients admitted with cardiac arrest during the study period, 47 patients had the 3 ECG and telemetry data available. ECG analysis was blinded and performed with manual caliper by two independent cardiologists from blinded copies of original ECG, recorded at 25 mm/s and 10 mm/mV. Coronary care unit staff analyzed ECG telemetry for rhythm disturbances. Variables measured in ECG were rhythm, RR, PR, QT and corrected QT (QTc by Bazett formula, measured in lead v2) intervals, QRS duration, presence of Osborn’s J wave and U wave, as well as ST segment displacement and T wave amplitude in leads II, v2 and v5. RESULTS: Heart rate went down an average of 19 bpm during hypothermia and increased again 16 bpm with rewarming (P < 0.0005, both). There was a non-significant prolongation of the PR interval during TH and a significant decrease with rewarming (P = 0.041). QRS duration significantly prolonged (P = 0.041) with TH and shortened back (P < 0.005) with rewarming. QTc interval presented a mean prolongation of 58 ms (P < 0.005) during TH and a significant shortening with rewarming of 22.2 ms (P = 0.017). Osborn or J wave was found in 21.3% of the patients. New arrhythmias occurred in 38.3% of the patients. Most frequent arrhythmia was non-sustained ventricular tachycardia (19.1%), followed by severe bradycardia or paced rhythm (10.6%), accelerated nodal rhythm (8.5%) and atrial fibrillation (6.4%). No life threatening arrhythmias (sustained ventricular tachycardia, polymorphic ventricular tachycardia or

  2. Hypothermia and rewarming induce gene expression and multiplication of cells in healthy rat prostate tissue.

    PubMed

    Kaija, Helena; Pakanen, Lasse; Kortelainen, Marja-Leena; Porvari, Katja

    2015-01-01

    Prostate cancer has been extensively studied, but cellular stress responses in healthy prostate tissue are rarely investigated. Hypothermia is known to cause alterations in mRNA and protein expressions and stability. The aim of this study was to use normal rat prostate as a model in order to find out consequences of cold exposure and rewarming on the expressions of genes which are either members or functionally/structurally related to erythroblastic leukemia viral oncogene B (ErbB) signaling pathway. Relative mRNA expressions of amphiregulin (AMR), cyclin D1 (CyD1), cyclin-dependent kinase inhibitor 1A (p21), transmembrane form of the prostatic acid phosphatase (PAcP), thrombomodulin (TM) and heat shock transcription factor 1 (HSF1) in rat ventral prostate were quantified in mild (2 or 4.5 h at room temperature) and severe (2 or 4.5 h at +10°C) hypothermia and in rewarming after cold exposure (2 h at +10°C followed by 2 h at room temperature or 3 h at +28°C). AMR protein level, apoptotic Bcl-2 associated X protein to B-cell CLL/lymphoma 2 (Bax/Bcl-2) mRNA ratio and proliferative index Ki-67 were determined. 4.5-h mild hypothermia, 2-h severe hypothermia and rewarming increased expression of all these genes. Elevated proliferation index Ki-67 could be seen in 2-h severe hypothermia, and the proliferation index had its highest value in longer rewarming with totally recovered normal body temperature. Pro-apoptotic tendency could be seen in 2-h mild hypothermia while anti-apoptosis was predominant in 4.5-h mild hypothermia and in shorter rewarming with only partly recovered body temperature. Hypothermia and following rewarming promote the proliferation of cells in healthy rat prostate tissue possibly via ErbB signaling pathway.

  3. Involvement of endogenous central hydrogen sulfide (H2S) in hypoxia-induced hypothermia in spontaneously hypertensive rats.

    PubMed

    Sabino, João Paulo J; Soriano, Renato N; Donatti, Alberto F; Fernandez, Rodrigo Restrepo; Kwiatkoski, Marcelo; Francescato, Heloísa D C; Coimbra, Terezila M; Branco, Luiz G S

    2017-02-01

    Spontaneously hypertensive rats (SHR) display autonomic imbalance and abnormal body temperature (Tb) adjustments. Hydrogen sulfide (H2S) modulates hypoxia-induced hypothermia, but its role in SHR thermoregulation is unknown. We tested the hypothesis that SHR display peculiar thermoregulatory response to hypoxia and that endogenous H2S overproduced in the caudal nucleus of the solitary tract (NTS) of SHR modulates this response. SHR and Wistar rats were microinjected into the fourth ventricle with aminooxyacetate (AOA, H2S-synthezing enzyme inhibitor) or sodium sulfide (Na2S, H2S donor) and exposed to normoxia (21% inspired O2) or hypoxia (10% inspired O2, 30 min). Tb was continuously measured, and H2S production rate was assessed in caudal NTS homogenates. In both groups, AOA, Na2S, or saline (i.e., control; 1 μL) did not affect euthermia. Hypoxia caused similar decreases in Tb in both groups. AOA presented a longer latency to potentiate hypoxic hypothermia in SHR. Caudal NTS H2S production rate was higher in SHR. We suggest that increased bioavailability of H2S in the caudal NTS of SHR enables the adequate modulation of excitability of peripheral chemoreceptor-activated NTS neurons that ultimately induce suppression of brown adipose tissue thermogenesis, thus accounting for the normal hypoxic hypothermia.

  4. Brief Rewarming Blunts Hypothermia-Induced Alterations in Sensation, Motor Drive and Cognition

    PubMed Central

    Brazaitis, Marius; Paulauskas, Henrikas; Skurvydas, Albertas; Budde, Henning; Daniuseviciute, Laura; Eimantas, Nerijus

    2016-01-01

    hypothermia-induced alterations in neural drive transmission (4.3 ± 0.5 vs. 3.4 ± 0.8 mV H-reflex and 4.9 ± 0.2 vs. 4.4 ± 0.4 mV V-wave, P < 0.05), which increased central fatigue during a 2-min maximum load (P < 0.05). Furthermore, only in brief warm water rewarming cerebral alterations were restored to the control level and it was indicated by shortened reaction times (P < 0.05). Conclusions: Brief rewarming in warm water rather than the same duration rewarming in thermoneutral environment blunted the hypothermia-induced alterations for sensation, motor drive, and cognition, despite the fact that rectal and deep muscle temperature remained lowered. PMID:27990123

  5. Handling Hypothermia.

    ERIC Educational Resources Information Center

    Saho, S. Bamba

    1996-01-01

    Presents a unit on the body's response to hypothermia. Includes activities in which students measure the amount of heat absorbed by a white piece of cloth and a black piece of the same material, use cooperative-learning techniques to design a graphic organizer that explains metabolic responses to cold stress, and study the effect of temperature on…

  6. Sarcosine attenuates toluene-induced motor incoordination, memory impairment, and hypothermia but not brain stimulation reward enhancement in mice

    SciTech Connect

    Chan, Ming-Huan; Chung, Shiang-Sheng; Stoker, Astrid K.; Markou, Athina; Chen, Hwei-Hsien

    2012-12-01

    Toluene, a widely used and commonly abused organic solvent, produces various behavioral disturbances, including motor incoordination and cognitive impairment. Toluene alters the function of a large number of receptors and ion channels. Blockade of N-methyl-D-aspartate (NMDA) receptors has been suggested to play a critical role in toluene-induced behavioral manifestations. The present study determined the effects of various toluene doses on motor coordination, recognition memory, body temperature, and intracranial self-stimulation (ICSS) thresholds in mice. Additionally, the effects of sarcosine on the behavioral and physiological effects induced by toluene were evaluated. Sarcosine may reverse toluene-induced behavioral manifestations by acting as an NMDA receptor co-agonist and by inhibiting the effects of the type I glycine transporter (GlyT1). Mice were treated with toluene alone or combined with sarcosine pretreatment and assessed for rotarod performance, object recognition memory, rectal temperature, and ICSS thresholds. Toluene dose-dependently induced motor incoordination, recognition memory impairment, and hypothermia and lowered ICSS thresholds. Sarcosine pretreatment reversed toluene-induced changes in rotarod performance, novel object recognition, and rectal temperature but not ICSS thresholds. These findings suggest that the sarcosine-induced potentiation of NMDA receptors may reverse motor incoordination, memory impairment, and hypothermia but not the enhancement of brain stimulation reward function associated with toluene exposure. Sarcosine may be a promising compound to prevent acute toluene intoxications by occupational or intentional exposure. -- Highlights: ► Toluene induces impairments in Rotarod test and novel object recognition test. ► Toluene lowers rectal temperature and ICSS thresholds in mice. ► Sarcosine reverses toluene-induced changes in motor, memory and body temperature. ► Sarcosine pretreatment does not affect toluene-induced

  7. Accidental hypothermia in severe trauma.

    PubMed

    Vardon, Fanny; Mrozek, Ségolène; Geeraerts, Thomas; Fourcade, Olivier

    2016-10-01

    Hypothermia, along with acidosis and coagulopathy, is part of the lethal triad that worsen the prognosis of severe trauma patients. While accidental hypothermia is easy to identify by a simple measurement, it is no less pernicious if it is not detected or treated in the initial phase of patient care. It is a multifactorial process and is a factor of mortality in severe trauma cases. The consequences of hypothermia are many: it modifies myocardial contractions and may induce arrhythmias; it contributes to trauma-induced coagulopathy; from an immunological point of view, it diminishes inflammatory response and increases the chance of pneumonia in the patient; it inhibits the elimination of anaesthetic drugs and can complicate the calculation of dosing requirements; and it leads to an over-estimation of coagulation factor activities. This review will detail the pathophysiological consequences of hypothermia, as well as the most recent principle recommendations in dealing with it.

  8. Critical role for peripherally-derived interleukin-10 in mediating the thermoregulatory manifestations of fever and hypothermia in severe forms of lipopolysaccharide-induced inflammation.

    PubMed

    Harden, Lois M; Rummel, Christoph; Laburn, Helen P; Damm, Jelena; Wiegand, Florian; Poole, Stephen; Gerstberger, Rüdiger; Roth, Joachim

    2014-07-01

    Although peripherally released interleukin (IL)-10 has a critical regulatory role in limiting fever in mild-to-moderate forms of inflammation, its role in regulating the more complex thermoregulatory manifestations of hypothermia and fever noted during severe inflammation is less clear. Using cytokine antagonism, we therefore investigated the involvement of peripherally released IL-10 in mediating hypothermia, fever and inflammation induced by intraperitoneal (IP) administration of a large dose of lipopolysaccharide (LPS). Male Wistar rats (200-250 g) were anaesthetized and implanted intra-abdominally with temperature-sensitive radiotelemeters. Rats were randomly assigned to receive IL-10 antiserum (IL-10AS) or normal sheep serum IP, 4 h before receiving an IP injection of LPS (10 mg/kg) or phosphate-buffered saline (PBS). Inflammatory responses were measured in plasma and tissue samples (spleen, liver and brain) at 90 min and 6 h after the IP injection of LPS or PBS. Administration of LPS induced an initial period of hypothermia (~90 min) after which fever developed. Pre-treating rats with IL-10AS abolished the LPS-induced increase in plasma IL-10 levels, attenuated the hypothermia and increased the amplitude of the fever. Moreover, IL-10AS pre-treatment augmented the LPS-induced increase in plasma levels of tumor necrosis factor-alpha (90 min and 6 h), IL-1β (90 min), prostaglandin E2 (90 min) and IL-6 (6 h), in the periphery, but not the hypothalamus, over the duration of hypothermia and fever. Via its action on the synthesis of inflammatory mediators in the spleen and liver, endogenous IL-10 plays a crucial regulatory role in mediating hypothermia and fever during severe aspectic (LPS-induced) systemic inflammation.

  9. Utilization of Hyperbaric Oxygen Therapy and Induced Hypothermia After Hydrogen Sulfide Exposure

    PubMed Central

    Asif, Mir J.; Exline, Matthew C.

    2013-01-01

    Hydrogen sulfide is a toxic gas produced as a byproduct of organic waste and many industrial processes. Hydrogen sulfide exposure symptoms may vary from mild (dizziness, headaches, nausea) to severe lactic acidosis via its inhibition of oxidative phosphorylation, leading to cardiac arrhythmias and death. Treatment is generally supportive. We report the case of a patient presenting with cardiac arrest secondary to hydrogen sulfide exposure treated with both hyperbaric oxygen therapy and therapeutic hypothermia with great improvement in neurologic function. PMID:22004989

  10. Prolonged induced hypothermia in hemorrhagic shock is associated with decreased muscle metabolism: a nuclear magnetic resonance-based metabolomics study.

    PubMed

    Lusczek, Elizabeth R; Lexcen, Daniel R; Witowski, Nancy E; Determan, Charles; Mulier, Kristine E; Beilman, Greg

    2014-01-01

    Hemorrhagic shock is a leading cause of trauma-related death in war and is associated with significant alterations in metabolism. Using archived serum samples from a previous study, the purpose of this work was to identify metabolic changes associated with induced hypothermia in a porcine model of hemorrhagic shock. Twelve Yorkshire pigs underwent a standardized hemorrhagic shock and resuscitation protocol to simulate battlefield injury with prolonged evacuation to definitive care in cold environments. Animals were randomized to receive either hypothermic (33°C) or normothermic (39°C) limited resuscitation for 8 h, followed by standard resuscitation. Proton nuclear magnetic resonance spectroscopy was used to evaluate serum metabolites from these animals at intervals throughout the hypothermic resuscitation period. Animals in the hypothermic group had a significantly higher survival rate (P = 0.02) than normothermic animals. Using random forest analysis, a difference in metabolic response between hypothermic and normothermic animals was identified. Hypothermic resuscitation was characterized by decreased concentrations of several muscle-related metabolites including taurine, creatine, creatinine, and amino acids. This study suggests that a decrease in muscle metabolism as a result of induced hypothermia is associated with improved survival.

  11. Anesthesia-Induced Hypothermia Attenuates Early-Phase Blood-Brain Barrier Disruption but Not Infarct Volume following Cerebral Ischemia.

    PubMed

    Liu, Yu-Cheng; Lee, Yu-Da; Wang, Hwai-Lee; Liao, Kate Hsiurong; Chen, Kuen-Bao; Poon, Kin-Shing; Pan, Yu-Ling; Lai, Ted Weita

    2017-01-01

    Blood-brain barrier (BBB) disruption is thought to facilitate the development of cerebral infarction after a stroke. In a typical stroke model (such as the one used in this study), the early phase of BBB disruption reaches a peak 6 h post-ischemia and largely recovers after 8-24 h, whereas the late phase of BBB disruption begins 48-58 h post-ischemia. Because cerebral infarct develops within 24 h after the onset of ischemia, and several therapeutic agents have been shown to reduce the infarct volume when administered at 6 h post-ischemia, we hypothesized that attenuating BBB disruption at its peak (6 h post-ischemia) can also decrease the infarct volume measured at 24 h. We used a mouse stroke model obtained by combining 120 min of distal middle cerebral arterial occlusion (dMCAo) with ipsilateral common carotid arterial occlusion (CCAo). This model produced the most reliable BBB disruption and cerebral infarction compared to other models characterized by a shorter duration of ischemia or obtained with dMCAO or CCAo alone. The BBB permeability was measured by quantifying Evans blue dye (EBD) extravasation, as this tracer has been shown to be more sensitive for the detection of early-phase BBB disruption compared to other intravascular tracers that are more appropriate for detecting late-phase BBB disruption. We showed that a 1 h-long treatment with isoflurane-anesthesia induced marked hypothermia and attenuated the peak of BBB disruption when administered 6 h after the onset of dMCAo/CCAo-induced ischemia. We also demonstrated that the inhibitory effect of isoflurane was hypothermia-dependent because the same treatment had no effect on ischemic BBB disruption when the mouse body temperature was maintained at 37°C. Importantly, inhibiting the peak of BBB disruption by hypothermia had no effect on the volume of brain infarct 24 h post-ischemia. In conclusion, inhibiting the peak of BBB disruption is not an effective neuroprotective strategy, especially in comparison

  12. Anesthesia-Induced Hypothermia Attenuates Early-Phase Blood-Brain Barrier Disruption but Not Infarct Volume following Cerebral Ischemia

    PubMed Central

    Liu, Yu-Cheng; Lee, Yu-Da; Wang, Hwai-Lee; Liao, Kate Hsiurong; Chen, Kuen-Bao; Poon, Kin-Shing; Pan, Yu-Ling

    2017-01-01

    Blood-brain barrier (BBB) disruption is thought to facilitate the development of cerebral infarction after a stroke. In a typical stroke model (such as the one used in this study), the early phase of BBB disruption reaches a peak 6 h post-ischemia and largely recovers after 8–24 h, whereas the late phase of BBB disruption begins 48–58 h post-ischemia. Because cerebral infarct develops within 24 h after the onset of ischemia, and several therapeutic agents have been shown to reduce the infarct volume when administered at 6 h post-ischemia, we hypothesized that attenuating BBB disruption at its peak (6 h post-ischemia) can also decrease the infarct volume measured at 24 h. We used a mouse stroke model obtained by combining 120 min of distal middle cerebral arterial occlusion (dMCAo) with ipsilateral common carotid arterial occlusion (CCAo). This model produced the most reliable BBB disruption and cerebral infarction compared to other models characterized by a shorter duration of ischemia or obtained with dMCAO or CCAo alone. The BBB permeability was measured by quantifying Evans blue dye (EBD) extravasation, as this tracer has been shown to be more sensitive for the detection of early-phase BBB disruption compared to other intravascular tracers that are more appropriate for detecting late-phase BBB disruption. We showed that a 1 h-long treatment with isoflurane-anesthesia induced marked hypothermia and attenuated the peak of BBB disruption when administered 6 h after the onset of dMCAo/CCAo-induced ischemia. We also demonstrated that the inhibitory effect of isoflurane was hypothermia-dependent because the same treatment had no effect on ischemic BBB disruption when the mouse body temperature was maintained at 37°C. Importantly, inhibiting the peak of BBB disruption by hypothermia had no effect on the volume of brain infarct 24 h post-ischemia. In conclusion, inhibiting the peak of BBB disruption is not an effective neuroprotective strategy, especially in

  13. Impairment of Rat Spatial Learning and Memory in a New Model of Cold Water-Induced Chronic Hypothermia: Implication for Alzheimer's Disease.

    PubMed

    Ahmadian-Attari, Mohammad Mahdi; Dargahi, Leila; Mosaddegh, Mahmoud; Kamalinejad, Mohammad; Khallaghi, Behzad; Noorbala, Fatemeh; Ahmadiani, Abolhassan

    2015-08-01

    Alzheimer's disease (AD) is a primary neurodegenerative disorder associated with progressive memory impairment. Recent studies suggest that hypothermia may contribute to the development and exacerbation of AD. The aim of this study was to investigate the role of chronic hypothermia on spatial learning and memory performance as well as brain immunohistochemical (IHC) and molecular changes. Four groups of male rats were placed in cold water (3.5 ± 0.5 °C) once a day for 1, 3, 6, and 14 days, four other groups were placed in warm water (32 °C) as the control groups to eliminate the effect of swimming stress, and one more group which comprised intact animals that were kept in a normothermic situation and had no swimming stress. Twenty-four hours after the last intervention, spatial learning and memory were assessed, using the modified Morris water maze. After the behavioral test, the rats' brains were removed for IHC and Western blotting. The results showed that memory retrieval is impaired after 14 days of cold water-induced hypothermia (CWH) (P < 0.05). IHC showed the formation of beta-amyloid plaques after a 14-day CWH. The molecular changes demonstrated that a 14-day CWH induces tau hyperphosphorylation, apoptosis, and reduces COX-II expression. Therefore, chronic CWH, independent of forced swimming stress, impairs learning and memory through molecular mechanisms similar to those of AD. In conclusion, CWH may serve as an important model to assess the role of hypothermia in AD pathogenesis.

  14. Hypothermia: First Aid

    MedlinePlus

    ... Hypothermia is often caused by exposure to cold weather or immersion in a cold body of water. ... Minn. Feb. 25, 2015. Frostbite and hypothermia. National Weather Service Weather Forecast Office. http://www.crh.noaa. ...

  15. Chronic Cold-Water-Induced Hypothermia Impairs Memory Retrieval and Nepeta menthoides as a Traditional "Hot" Herb Reverses the Impairment.

    PubMed

    Ahmadian-Attar, Mohammad Mahdi; Ahmadiani, Abolhassan; Kamalinejad, Mohammad; Dargahi, Leila; Mosaddegh, Mahmoud

    2014-01-01

    Iranian Traditional Medicine (ITM) describes a kind of dementia with similar signs and symptoms of Alzheimer's disease (AD). It explains the pathology of dementia with cold intemperament of the brain, which means that the brain is colder than its healthy form. ITM strategy for treatment of dementia is to heat the brain up by medical "hot" herbs. Nepeta menthoides (NM) is one of these "hot" herbs. To evaluate the veracity of ITM concept about dementia and its treatment, we first try to examine if coldness of brain can make memory impairment. If so, can NM reverse memory impairment? Rats in cold-water-induced hypothermic (CWH) groups were immersed up to the neck in 3.5 °C water, for 5 min during 14 consecutive days. As a control, rats were forced to swim in warm water at the same conditions. To eliminate the impact of forced swimming stress, a group of intact rats was also added. After last swimming in day 14, some groups received drug (100 or 500 mg/ Kg aqueous extract of NM) or vehicle via i.p. injection. Learning and memory were assessed by Morris water maze, and tau hyperphosphorylation was measured by western blotting. The results showed that CWH impairs learning and memory and induces tau hyperphosphorylation. 100 mg/Kg of NM reversed memory impairment as well as tau hyperphosphorylation. ITM theory about the relationship between brain hypothermia and dementia is in accordance with our findings.

  16. Intra-carotid cold magnesium sulfate infusion induces selective cerebral hypothermia and neuroprotection in rats with transient middle cerebral artery occlusion.

    PubMed

    Song, Wei; Wu, Yong-Ming; Ji, Zhong; Ji, Ya-Bin; Wang, Sheng-Nan; Pan, Su-Yue

    2013-04-01

    Local hypothermia induced by intra-arterial infusion of cold saline reduces brain injury in ischemic stroke. Administration of magnesium sulfate through the internal carotid artery is also known to reduce ischemic brain damage. The neuroprotective effects of combination therapy with local endovascular hypothermia and intra-carotid magnesium sulfate infusion has not been evaluated. The aim of the study was to determine whether infusion of intra-carotid cold magnesium offers neuroprotective efficacy superior to cold saline infusion alone. Sixty-eight Sprague-Dawley rats were subjected to 3 h of middle cerebral artery occlusion and were randomly divided into six groups: sham-operated group; stroke control group; local cold magnesium infusion group; local cold saline infusion group; local normothermic magnesium infusion group; and local normothermic saline infusion group. Before reperfusion, ischemic rats received local infusion or no treatment. Infarct volume, neurological deficit, and brain water content were evaluated at 48 h after reperfusion. Selective brain hypothermia (33-34 °C) was successfully induced by intra-carotid cold infusion. Local cold saline infusion and local cold magnesium infusion reduced the infarct volumes by 48 % (p < 0.001) and 65 % (p < 0.001), respectively, compared with stroke controls. Brain water content was decreased significantly in animals treated with local cold magnesium infusion. Furthermore, the rats given a local cold magnesium infusion had the best neurological outcome. Local normothermic infusion failed to improve ischemic brain damage. These data suggest that local hypothermia induced by intra-carotid administration of cold magnesium is more effective in reducing acute ischemic damage than infusion of cold saline alone.

  17. Guideline Implementation: Preventing Hypothermia.

    PubMed

    Bashaw, Marie A

    2016-03-01

    The updated AORN "Guideline for prevention of unplanned patient hypothermia" provides guidance for identifying factors associated with intraoperative hypothermia, preventing hypothermia, educating perioperative personnel on this topic, and developing relevant policies and procedures. This article focuses on key points of the guideline, which addresses performing a preoperative assessment for factors that may contribute to hypothermia, measuring and monitoring the patient's temperature in all phases of perioperative care, and implementing interventions to prevent hypothermia. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures.

  18. Serum cortisol concentrations during induced hypothermia for perinatal asphyxia are associated with neurological outcome in human infants.

    PubMed

    Scaramuzzo, Rosa T; Giampietri, Matteo; Fiorentini, Erika; Bartalena, Laura; Fiori, Simona; Guzzetta, Andrea; Ciampi, Mariella; Boldrini, Antonio; Ghirri, Paolo

    2015-01-01

    Birth asphyxia is a cause of neonatal death or adverse neurological sequelae. Biomarkers can be useful to clinicians in order to optimize intensive care management and communication of prognosis to parents. During perinatal adverse events, increased cortisol secretion is due to hypothalamo-pituitary-adrenal axis activation. We aimed to investigate if cortisol variations during therapeutic hypothermia are associated with neurodevelopmental outcome. We compared 18 cases (neonates with birth asphyxia) with 18 controls (healthy term newborns) and confirmed increased serum cortisol concentrations following the peri-partum adverse event. Among cases, we stratified patients according to neurological outcome at 18 months (group A - good; group B - adverse) and found that after 24 h of therapeutic hypothermia serum cortisol concentration was significantly lower in group A vs group B (28.7 ng/mL vs 344 ng/mL, *p = 0.01). In group B serum, cortisol concentration decreased more gradually during therapeutic hypothermia. We conclude that monitoring serum cortisol concentration during neonatal therapeutic hypothermia can add information to clinical evaluation of neonates with birth asphyxia; cortisol values after the first 24 h of hypothermia can be a biomarker associated with neurodevelopmental outcome at 18 months of age.

  19. State of the Art in Therapeutic Hypothermia

    PubMed Central

    Lampe, Joshua W.; Becker, Lance B.

    2012-01-01

    Historically, hypothermia was induced prior to surgery to enable procedures with prolonged ischemia, such as open heart surgery and organ transplant. Within the past decade, the efficacy of hypothermia to treat emergency cases of ongoing ischemia such as stroke, myocardial infarction, and cardiac arrest has been studied. Although the exact role of ischemia/reperfusion is unclear clinically, hypothermia holds significant promise for improving outcomes for patients suffering from reperfusion after ischemia. Research has elucidated two distinct windows of opportunity for clinical use of hypothermia. In the early intra-ischemia window, hypothermia modulates abnormal cellular free radical production, poor calcium management, and poor pH management. In the more delayed post-reperfusion window, hypothermia modulates the downstream necrotic, apoptotic, and inflammatory pathways that cause delayed cell death. Improved cooling and monitoring technologies are required to realize the full potential of this therapy. Herein we discuss the current state of clinical practice, clinical trials, recommendations for cooling, and ongoing research on therapeutic hypothermia. PMID:20854174

  20. [Induced hypothermia/normothermia with general anesthesia prevents neurological damage in children with febrile refractory status epilepticus].

    PubMed

    Nakagawa, Taku; Fujita, Kyoko; Saji, Yohsuke; Maruyama, Azusa; Nagase, Hiroaki

    2011-11-01

    Refractory status epilepticus (RSE) is defined as persistence of seizure activity despite appropriate medical and antiepileptic drug (AED) therapy. Febrile RSE is often caused by presumed encephalitis and has a high morbidity rate. In addition, it is believed that hyperthermia aggravates epileptic brain damage. The efficacy of hypothermia/normothermia (H/N) therapy against brain damage has been proposed, but there have been limited studies reporting on the efficacy of this treatment against febrile RSE. To study the efficacy of induced H/N with general anesthesia therapy in children with febrile RSE, a retrospective review of RSE cases was conducted in 28 children hospitalized in the tertiary pediatric intensive care center of Kobe Children's Hospital, Japan, between October 2002 and August 2009. Clinical outcomes and neurological sequelae using the Pediatric Cerebral Performance Category Scale (PCPC) score were compared after one month of treatment with either H/N (34 degrees C-36 degrees C) with general anesthesia therapy or with other conventional therapies. Cases were categorized as those with good recovery (PCPC=1) or poor outcome (PCPC=2-6). Twelve children underwent H/N with general anesthesia therapy, while 16 children were treated by conventional therapy using intravenous diazepam and/or midazolam. Treatment with H/N significantly improved outcome compared to conventional therapies (p=0.024; Fisher's exact test). Five of 6 patients with poor outcome had a final diagnosis of acute encephalopathy with febrile convulsive status epilepticus (AEFCSE). Treatment with H/N therapy may reduce neurological damage in the development of AEFCSE caused by febrile RSE in children.

  1. C5a receptor (CD88) inhibition improves hypothermia-induced neuroprotection in an in vitro ischemic model.

    PubMed

    Thundyil, John; Pavlovski, Dale; Hsieh, Yu-Hsuan; Gelderblom, Mathias; Magnus, Tim; Fairlie, David P; Arumugam, Thiruma V

    2012-03-01

    The concept of 'salvageble penumbra' has prompted both scientists and physicians to explore various neuroprotective approaches that could be beneficial during stroke therapy. Unfortunately, most of them have proved ineffective in targeting multiple cellular death cascades incited within the ischemic penumbra. Hypothermia has been shown to be capable of addressing this problem to some extent. Although many studies have shown that hypothermia targets several cellular processes, its effects on innate immune receptor-mediated apoptotic death still remain unclear. Moreover, whether inhibiting the signaling of innate immune receptors like complement anaphylatoxin C5a receptor (CD88) plays a role in this hypothermic neuroprotection still need to be deciphered. Using various types of ischemic insults in different neuronal cells, we confirm that hypothermia does indeed attenuate apoptotic neuronal cell death in vitro and this effect can be further enhanced by pharmacologically blocking or knocking out CD88. Thus, our study raises a promising therapeutic possibility of adding CD88 antagonists along with hypothermia to improve stroke outcomes.

  2. Oxidative Stress and Antioxidant Activity in Hypothermia and Rewarming: Can RONS Modulate the Beneficial Effects of Therapeutic Hypothermia?

    PubMed Central

    Alva, Norma; Palomeque, Jesús

    2013-01-01

    Hypothermia is a condition in which core temperature drops below the level necessary to maintain bodily functions. The decrease in temperature may disrupt some physiological systems of the body, including alterations in microcirculation and reduction of oxygen supply to tissues. The lack of oxygen can induce the generation of reactive oxygen and nitrogen free radicals (RONS), followed by oxidative stress, and finally, apoptosis and/or necrosis. Furthermore, since the hypothermia is inevitably followed by a rewarming process, we should also consider its effects. Despite hypothermia and rewarming inducing injury, many benefits of hypothermia have been demonstrated when used to preserve brain, cardiac, hepatic, and intestinal function against ischemic injury. This review gives an overview of the effects of hypothermia and rewarming on the oxidant/antioxidant balance and provides hypothesis for the role of reactive oxygen species in therapeutic hypothermia. PMID:24363826

  3. Reversal by hypothermia of vasodilator-induced tachycardia in anesthetized rats.

    PubMed

    Vidrio, H; García-Márquez, F

    1987-08-01

    The normal cardiovascular response to hydralazine in urethane-anesthetized rats, i.e. hypotension and tachycardia, was changed to hypotension and bradycardia if the body temperature of the animals was not maintained constant by external heating, but was allowed to decrease spontaneously throughout the experiment. A similar phenomenon was observed with diazoxide. In rats maintained at a rectal temperature of 31 degrees C, hydralazine bradycardia was partially blocked by a low dose of atropine and was reversed to tachycardia by a high dose of this agent; mecamylamine failed to influence heart rate lowering in this condition. Heart rate responses in unheated animals to acetylcholine and isopropylarterenol were respectively potentiated and depressed when compared to responses in heated rats. These findings suggest that cold-induced reciprocal changes in reactivity of cardiac muscarinic and beta-adrenoceptors may be responsible for reversal of hydralazine or diazoxide tachycardia in urethane-anesthetized hypothermic rats. As a result, cardiac stimulation by the sympatho-adrenal discharge induced by hypotension is inhibited, while cardiac depression which is apparently also induced by hypotension, is facilitated. It is speculated that vasopressin, released as a consequence of the blood pressure fall, could be this negative chronotropic factor.

  4. [Physiologic effects of hypothermia].

    PubMed

    Kovács, Eniko; Jenei, Zsigmond; Horváth, Anikó; Gellér, László; Szilágyi, Szabolcs; Király, Akos; Molnár, Levente; Sótonyi, Péter; Merkely, Béla; Zima, Endre

    2011-01-30

    Therapeutic use of hypothermia has come to the frontline in the past decade again in the prevention and in mitigation of neurologic impairment. The application of hypothermia is considered as a successful therapeutic measure not just in neuro- or cardiac surgery, but also in states causing brain injury or damage. According to our present knowledge this is the only proven therapeutic tool, which improves the neurologic outcome after cardiac arrest, decreasing the oxygen demand of the brain. Besides influencing the nervous system, hypothermia influences the function of the whole organ system. Beside its beneficial effects, it has many side-effects, which may be harmful to the patient. Before using it for a therapeutic purpose, it is very important to be familiar with the physiology and complications of hypothermia, to know, how to prevent and treat its side-effects. The purpose of this article is to summarize the physiologic and pathophysiologic effects of hypothermia.

  5. Prevention of unplanned perioperative hypothermia.

    PubMed

    Paulikas, Cynthia A

    2008-09-01

    Hypothermia is one of the most common complications experienced by surgical patients. Better postoperative patient outcomes are achieved when normothermia is maintained. Perioperative nurses should understand how to maintain normothermia, the causes of hypothermia, and adverse patient outcomes that result from hypothermia. Nursing interventions to help prevent hypothermia can be implemented during each phase of perioperative care.

  6. Effects of citicoline used alone and in combination with mild hypothermia on apoptosis induced by focal cerebral ischemia in rats.

    PubMed

    Sahin, S; Alkan, T; Temel, S G; Tureyen, K; Tolunay, S; Korfali, E

    2010-02-01

    The effects of citicoline used either alone or in combination with hypothermia on the suppression of apoptotic processes after transient focal cerebral ischemia were investigated. Middle cerebral artery occlusion (MCAo) was performed for 2 hours on Sprague-Dawley (SD) rats using intraluminal thread insertion. The treatment groups were as follows: Group 1, sham-operated; Group 2, saline; Group 3, citicoline (400mg/kg intraperitoneal.); Group 4, hypothermia (34+/-1 degrees C); Group 5, citicoline+hypothermia. All rats were reperfused for 24 hours, and after sacrifice and transcardiac perfusion, immunohistochemical studies were performed for markers of apoptosis. In Group 2, the Bcl-2 immunostaining score (mean+/-standard deviation, 0.71+/-0.75) was lower compared to Groups 3, 4 and 5 (2.33+/-0.81; 3.00+/-0.00; 2.20+/-0.83; p<0.05). There was higher expression of caspase-3 proteins in Group 2 (2.28+/-0.95) compared to Group 5 (1.50+/-0.83; p<0.05). Bax proteins were also increased in Group 2 (1.85+/-1.06) compared to Group 5 (0.40+/-0.54) and in Group 4 (2.00+/-0.00) compared to Group 5 (0.40+/-0.54; p<0.05). Significant differences in caspase-9 immunostaining scores were found in Group 2 (2.29+/-0.96) compared to Group 5 (0.20+/-0.44) (p<0.05); Group 3 (1.00+/-0.70) compared to Group 5 (0.20+/-0.44; p<0.05); and Group 4 (3.00+/-0.00; p<0.05) compared to Group 5 (0.40+/-0.54; p<0.05). Thus by suppressing apoptotic processes citicoline with hypothermia is more effective than either used alone in ameliorating cerebral damage after transient focal ischemia.

  7. Evaluation of the protection exerted by Pisum sativum Ferredoxin-NADP(H) Reductase against injury induced by hypothermia on Cos-7 cells.

    PubMed

    Pucci Molineris, M; Di Venanzio, G; Mamprin, M E; Mediavilla, M G

    2013-08-01

    Hypothermia is employed as a method to diminish metabolism rates and preserve tissues and cells. However, low temperatures constitute a stress that produces biochemical changes whose extension depends on the duration and degree of cold exposure and is manifested when physiological temperature is restored. For many cellular types, cold induces an oxidative stress that is dependent on the elevation of intracellular iron, damages macromolecules, and is prevented by the addition of iron chelators. Pisum sativum Ferredoxin-NADP(H) Reductase (FNR) has been implicated in protection from injury mediated by intracellular iron increase and successfully used to reduce oxidative damage on bacterial, plant and mammalian systems. In this work, FNR was expressed in Cos-7 cells; then, they were submitted to cold incubation and iron overload to ascertain whether this enzyme was capable of diminishing the harm produced by these challenges. Contrary to expected, FNR was not protective and even exacerbated the damage under certain circumstances. It was also found that the injury induced by hypothermia in Cos-7 cells presented both iron-dependent and iron-independent components of damage when cells were actively dividing but only iron-independent component when cells were in an arrested state. This is in agreement with previous findings which showed that iron-dependent damage is also an energy-dependent process.

  8. Therapeutic Hypothermia for Neuroprotection

    PubMed Central

    Karnatovskaia, Lioudmila V.; Wartenberg, Katja E.

    2014-01-01

    The earliest recorded application of therapeutic hypothermia in medicine spans about 5000 years; however, its use has become widespread since 2002, following the demonstration of both safety and efficacy of regimens requiring only a mild (32°C-35°C) degree of cooling after cardiac arrest. We review the mechanisms by which hypothermia confers neuroprotection as well as its physiological effects by body system and its associated risks. With regard to clinical applications, we present evidence on the role of hypothermia in traumatic brain injury, intracranial pressure elevation, stroke, subarachnoid hemorrhage, spinal cord injury, hepatic encephalopathy, and neonatal peripartum encephalopathy. Based on the current knowledge and areas undergoing or in need of further exploration, we feel that therapeutic hypothermia holds promise in the treatment of patients with various forms of neurologic injury; however, additional quality studies are needed before its true role is fully known. PMID:24982721

  9. The effect of hypothermia on influx of leukocytes in the digital lamellae of horses with oligofructose-induced laminitis.

    PubMed

    Godman, Jennifer D; Burns, Teresa A; Kelly, Carlin S; Watts, Mauria R; Leise, Britta S; Schroeder, Eric L; van Eps, Andrew W; Belknap, James K

    2016-10-01

    Sepsis-related laminitis (SRL) is a common complication in the septic/endotoxemic critically-ill equine patient, in which lamellar injury and failure commonly lead to crippling distal displacement of the distal phalanx. Similar to organ injury in human sepsis, lamellar injury in SRL has been associated with inflammatory events, including the influx of leukocytes into the lamellar tissue and markedly increased expression of a wide array of inflammatory mediators at the onset of Obel grade 1 (OG1) laminitis. The only treatment reported both clinically and experimentally to protect the lamellae in SRL, local hypothermia ("cryotherapy"), has been demonstrated to effectively inhibit lamellar expression of multiple inflammatory mediators when initiated at the time of administration of a carbohydrate overload in experimental models of SRL. However, the effect of hypothermia on leukocyte influx into affected tissue has not been assessed. We hypothesized that cryotherapy inhibits leukocyte emigration into the digital lamellae in SRL. Immunohistochemical staining using leukocyte markers MAC387 (marker of neutrophils, activated monocytes) and CD163 (monocyte/macrophage-specific marker) was performed on archived lamellar tissue samples from an experimental model of SRL in which one forelimb was maintained at ambient temperature (AMB) and one forelimb was immersed in ice water (ICE) immediately following enteral oligofructose administration (10g/kg, n=14 horses). Lamellae were harvested at 24h post-oligofructose administration (DEV, n=7) or at the onset of OG1 laminitis (OG1, n=7). Both MAC387-positive and CD163-positive cells were counted by a single blinded investigator on images [n=10 (40× fields/digit for MAC387 and 20x fields/digit for CD163)] obtained using Aperio microscopy imaging analysis software. Data were assessed for normality and analyzed with a paired t-test and one-way ANOVA with significance set at p<0.05. MAC387-positive cells were present in low numbers in

  10. Hypothermia for Neuroprotection in Convulsive Status Epilepticus.

    PubMed

    Legriel, Stephane; Lemiale, Virginie; Schenck, Maleka; Chelly, Jonathan; Laurent, Virginie; Daviaud, Fabrice; Srairi, Mohamed; Hamdi, Aicha; Geri, Guillaume; Rossignol, Thomas; Hilly-Ginoux, Julia; Boisramé-Helms, Julie; Louart, Benjamin; Malissin, Isabelle; Mongardon, Nicolas; Planquette, Benjamin; Thirion, Marina; Merceron, Sybille; Canet, Emmanuel; Pico, Fernando; Tran-Dinh, Yves-Roger; Bedos, Jean-Pierre; Azoulay, Elie; Resche-Rigon, Matthieu; Cariou, Alain

    2016-12-22

    Background Convulsive status epilepticus often results in permanent neurologic impairment. We evaluated the effect of induced hypothermia on neurologic outcomes in patients with convulsive status epilepticus. Methods In a multicenter trial, we randomly assigned 270 critically ill patients with convulsive status epilepticus who were receiving mechanical ventilation to hypothermia (32 to 34°C for 24 hours) in addition to standard care or to standard care alone; 268 patients were included in the analysis. The primary outcome was a good functional outcome at 90 days, defined as a Glasgow Outcome Scale (GOS) score of 5 (range, 1 to 5, with 1 representing death and 5 representing no or minimal neurologic deficit). The main secondary outcomes were mortality at 90 days, progression to electroencephalographically (EEG) confirmed status epilepticus, refractory status epilepticus on day 1, "super-refractory" status epilepticus (resistant to general anesthesia), and functional sequelae on day 90. Results A GOS score of 5 occurred in 67 of 138 patients (49%) in the hypothermia group and in 56 of 130 (43%) in the control group (adjusted common odds ratio, 1.22; 95% confidence interval [CI], 0.75 to 1.99; P=0.43). The rate of progression to EEG-confirmed status epilepticus on the first day was lower in the hypothermia group than in the control group (11% vs. 22%; odds ratio, 0.40; 95% CI, 0.20 to 0.79; P=0.009), but there were no significant differences between groups in the other secondary outcomes. Adverse events were more frequent in the hypothermia group than in the control group. Conclusions In this trial, induced hypothermia added to standard care was not associated with significantly better 90-day outcomes than standard care alone in patients with convulsive status epilepticus. (Funded by the French Ministry of Health; HYBERNATUS ClinicalTrials.gov number, NCT01359332 .).

  11. [Management of hypothermia -- Severe Accidental Hypothermia Centre in Krakow].

    PubMed

    Darocha, Tomasz; Kosiński, Sylweriusz; Jarosz, Anna; Sobczyk, Dorota; Gałązkowski, Robert; Sanak, Tomasz; Hymczak, Hubert; Kapelak, Bogusław; Drwiła, Rafał

    2015-01-01

    Severe accidental hypothermia is a condition associated with significant morbidity and mortality. In the years 2009–2012 the Polish National Statistics Department reported 1836 deaths due to exposure to excessive natural cold. The Severe Accidental Hypothermia Centre (CLHG, Centrum Leczenia Hipotermii Glebokiej) was set up in Krakow in 2013. It is a unit functioning within the structure of the Cardiac Surgery Clinic, established in order to improve the effectiveness of the treatment of patients in the advanced stages of severe hypothermia. Early identification of hypothermia, binding algorithm and coordination leading to extracorporeal rewarming, are the most important elements in the deep hypothermia management.

  12. Dipyrone metabolite 4-MAA induces hypothermia and inhibits PGE2-dependent and -independent fever while 4-AA only blocks PGE2-dependent fever

    PubMed Central

    Malvar, David do C; Aguiar, Fernando A; Vaz, Artur de L L; Assis, Débora C R; de Melo, Miriam C C; Jabor, Valquíria A P; Kalapothakis, Evanguedes; Ferreira, Sérgio H; Clososki, Giuliano C; de Souza, Glória E P

    2014-01-01

    BACKGROUND AND PURPOSE The antipyretic and hypothermic prodrug dipyrone prevents PGE2-dependent and -independent fever induced by LPS from Escherichia coli and Tityus serrulatus venom (Tsv) respectively. We aimed to identify the dipyrone metabolites responsible for the antipyretic and hypothermic effects. EXPERIMENTAL APPROACH Male Wistar rats were treated i.p. with indomethacin (2 mg·kg−1), dipyrone, 4-methylaminoantipyrine (4-MAA), 4-aminoantipyrine (4-AA) (60–360 mg·kg−1), 4-formylaminoantipyrine, 4-acethylaminoantipyrine (120–360 mg·kg−1) or vehicle 30 min before i.p. injection of LPS (50 μg·kg−1), Tsv (150 μg·kg−1) or saline. Rectal temperatures were measured by tele-thermometry and dipyrone metabolite concentrations determined in the plasma, CSF and hypothalamus by LC-MS/MS. PGE2 concentrations were determined in the CSF and hypothalamus by elisa. KEY RESULTS In contrast to LPS, Tsv-induced fever was not followed by increased PGE2 in the CSF or hypothalamus. The antipyretic time-course of 4-MAA and 4-AA on LPS-induced fever overlapped with the period of the highest concentrations of 4-MAA and 4-AA in the hypothalamus, CSF and plasma. These metabolites reduced LPS-induced fever and the PGE2 increase in the plasma, CSF and hypothalamus. Only 4-MAA inhibited Tsv-induced fever. The higher doses of dipyrone and 4-MAA also induced hypothermia. CONCLUSIONS AND IMPLICATIONS The presence of 4-MAA and 4-AA in the CSF and hypothalamus was associated with PGE2 synthesis inhibition and a decrease in LPS-induced fever. 4-MAA was also shown to be an antipyretic metabolite for PGE2-independent fever induced by Tsv suggesting that it is responsible for the additional antipyretic mechanism of dipyrone. Moreover, 4-MAA is the hypothermic metabolite of dipyrone. PMID:24712707

  13. Adult onset-hypothyroidism: alterations in hippocampal field potentials in the dentate gyrus are largely associated with anaesthesia-induced hypothermia.

    PubMed

    Sánchez-Huerta, K; Pacheco-Rosado, J; Gilbert, M E

    2015-01-01

    Thyroid hormone (TH) is essential for a number of physiological processes and is particularly critical during nervous system development. The hippocampus is strongly implicated in cognition and is sensitive to developmental hypothyroidism. The impact of TH insufficiency in the foetus and neonate on hippocampal synaptic function has been fairly well characterised. Although adult onset hypothyroidism has also been associated with impairments in cognitive function, studies of hippocampal synaptic function with late onset hypothyroidism have yielded inconsistent results. In the present study, we report hypothyroidism induced by the synthesis inhibitor propylthiouracil (10 p.p.m., 0.001%, minimum of 4 weeks), resulted in marginal alterations in excitatory postsynaptic potential (EPSP) and population spike (PS) amplitude in the dentate gyrus measured in vivo. No effects were seen in tests of short-term plasticity, and a minor enhancement of long-term potentiation of the EPSP slope was observed. The most robust synaptic alteration evident in hypothyroid animals was an increase in synaptic response latency, which was paralleled by a failure to maintain normal body temperature under anaesthesia, despite warming on a heating pad. Latency shifts could be reversed in hypothyroid animals by increasing the external heat source and, conversely, synaptic delays could be induced in control animals by removing the heat source, with a consequent drop in body and brain temperature. Thermoregulation is TH- dependent, and anaesthesia necessary for surgical procedures posed a thermoregulatory challenge that was differentially met in control and hypothyroid animals. Minor increases in field potential EPSP slope, decreases in PS amplitudes and increased latencies are consistent with previous reports of hypothermia in naive control rats. We conclude that failures in thyroid-dependent temperature regulation rather than direct action of TH in synaptic physiology are responsible for the

  14. A new microcontroller supervised thermoelectric renal hypothermia system.

    PubMed

    Işik, Hakan

    2005-10-01

    In the present study, a thermoelectric system controlled by a microcontroller is developed to induce renal hypothermia. Temperature value was managed by 8-byte microcontroller, PIC16F877, and was programmed using microcontroller MPASM package. In order to ensure hypothermia in the kidney 1-4 modules and sensors perceiving temperature of the area can be selected. Temperature values are arranged proportionately for the selected area and the determined temperature values can be monitored from an Liquid Crystal Display (LCD) screen. The temperature range of the system is between -50 and +50 degrees C. Renal hypothermia system was tried under in vivo conditions on the kidney of a dog.

  15. Quality of cardiopulmonary resuscitation affects cardioprotection by induced hypothermia at 34 °C against ischemia/reperfusion injury in a rat isolated heart model.

    PubMed

    Mochizuki, Toshiaki; Jiang, Qiliang; Katoh, Takasumi; Aoki, Katsunori; Sato, Shigehito

    2013-06-01

    In this study, we aimed to compare the effects of low- and high-quality cardiopulmonary resuscitation (CPR) on cardioprotection by induced hypothermia (IH) at 34 °C and examine whether extracellular signal-regulated kinase or endothelial nitric oxide synthase mediates this cardioprotection. Left ventricle infarct sizes were evaluated in six groups of rat hearts (n = 6) following Langendorff perfusion and triphenyltetrazolium chloride staining. Controls underwent 30 min of global ischemia at 37 °C, followed by 10 min of simulated low- or high-quality CPR reperfusion and 90 min of reperfusion at 75 mmHg. The IH groups underwent IH at 34 °C during reperfusion. The U0126 group received U0126 (60 μM)-an extracellular signal-regulated kinase inhibitor-during reperfusion at 34 °C. The L-NIO (N-(1-iminoethyl)-L-ornithine dihydrochloride) group received L-NIO (2 μM)-an endothelial nitric oxide synthase inhibitor-5 min before global ischemia at 37 °C to the end of reperfusion at 34 °C. Infarct size did not significantly differ between the control and IH groups receiving low-quality CPR. However, IH with high-quality CPR reduced the infarct size from 47.2% ± 10.2% to 26.0% ± 9.4% (P = 0.005). U0126 reversed the IH-induced cardioprotection (45.9% ± 9.4%, P = 0.010), whereas L-NIO had no significant effect. Cardiopulmonary resuscitation quality affects IH-induced cardioprotection. Extracellular signal-regulated kinase may mediate IH-induced cardioprotection.

  16. Hypothermia-induced platelet aggregation in human blood in an in vitro model: the dominant role of blood-material interactions.

    PubMed

    Hall, Matthew W; Solen, Kenneth A

    2002-03-05

    Hypothermia-induced platelet aggregation (HIPA) with or without neutrophil involvement may cause neurologic dysfunction during hypothermic surgery. We report the use of a previously developed model to study the contributions of several surfaces, surface area, shear rate, and blood-material exposure time to HIPA. Heparinized (1.5 u/mL) human blood was quenched to 24 degrees C and passed (0.5 mL/min) through a 75-cm long 1/32" ID tubing of polyvinylchloride (PVC), polyethylene (PE), polyurethane (PU), Teflon-FEP, or heparin (Duraflo)-coated PVC. The number of aggregates was measured by a light-scattering method, and the concentration of occlusive aggregates was assessed using constant-pressure filtration (50 mmHg). No differences were seen among PVC, PE, PU, or Teflon-FEP. The heparin-coated PVC tubing produced fewer occlusive aggregates, and heparin leaching from the coating was not the cause of the decrease in occlusive aggregates. Increasing surface area increased the number of aggregates, and increasing shear rates decreased the occlusiveness of those aggregates.

  17. Postmortem pulmonary CT in hypothermia.

    PubMed

    Schweitzer, Wolf; Thali, Michael; Giugni, Giannina; Winklhofer, Sebastian

    2014-12-01

    Fatal hypothermia has been associated with pulmonary edema. With postmortem full body computed tomography scanning (PMCT), the lungs can also be examined for CT attenuation. In fatal hypothermia cases low CT attenuation appeared to prevail in the lungs. We compared 14 cases of fatal hypothermia with an age-sex matched control group. Additionally, 4 cases of carbon monoxide (CO) poisoning were examined. Furthermore, 10 test cases were examined to test predictability based on PMCT. Two readers measured CT attenuation on four different axial slices across the lungs (blinded to case group and other reader's results). Hypothermia was associated with statistically significantly lower lung PMCT attenuation and lower lung weights than controls, and there was a dose-effect relationship at an environmental temperature cutoff of 2 °C. CO poisoning yielded low pulmonary attenuation but higher lung weights. General model based prediction yielded a 94% probability for fatal hypothermia deaths and a 21% probability for non-hypothermia deaths in the test group. Increased breathing rate is known to accompany both CO poisoning and hypothermia, so this could partly explain the low PMCT lung attenuation due to an oxygen dissociation curve left shift. A more marked distension in fatal hypothermia, compared to CO poisoning, indicates that further, possibly different mechanisms, are involved in these cases. Increased dead space and increased stiffness to deflation (but not inflation) appear to be effects of inhaling cold air (but not CO) that may explain the difference in low PMCT attenuation seen in hypothermia cases.

  18. Nurses' knowledge of inadvertent hypothermia.

    PubMed

    Hegarty, Josephine; Walsh, Ella; Burton, Aileen; Murphy, Sheila; O'gorman, Fionuala; McPolin, Gráinne

    2009-04-01

    Inadvertent hypothermia can have significant consequences in the perioperative setting. Knowing how to recognize and manage inadvertent hypothermia is an important aspect of perioperative nursing. A quantitative, descriptive study was conducted at an annual perioperative nursing conference to evaluate nurses' knowledge regarding the prevention of inadvertent perioperative hypothermia. Significant variations in responses regarding definitions of hypothermia and normothermia were noted. In addition, nurses identified a plethora of factors that prevent them from maintaining normothermia in their patients. These factors mandate a need for educational interventions and the adoption of practice guidelines in the clinical area.

  19. Hypothermia and the trauma patient

    PubMed Central

    Kirkpatrick, Andrew W.; Chun, Rosaleen; Brown, Ross; Simons, Richard K.

    Hypothermia has profound effects on every system in the body, causing an overall slowing of enzymatic reactions and reduced metabolic requirements. Hypothermic, acutely injured patients with multisystem trauma have adverse outcomes when compared with normothermic control patients. Trauma patients are inherently predisposed to hypothermia from a variety of intrinsic and iatrogenic causes. Coagulation and cardiac sequelae are the most pertinent physiological concerns. Hypothermia and coagulopathy often mandate a simplified approach to complex surgical problems. A modification of traditional classification systems of hypothermia, applicable to trauma patients is suggested. There are few controlled investigations, but clinical opinion strongly supports the active prevention of hypothermia in the acutely traumatized patient. Preventive measures are simple and inexpensive, but the active reversal of hypothermia is much more complicated, often invasive and controversial. The ideal method of rewarming is unclear but must be individualized to the patient and is institution specific. An algorithm reflecting newer approaches to traumatic injury and technical advances in equipment and techniques is suggested. Conversely, hypothermia has selected clinical benefits when appropriately used in cases of trauma. Severe hypothermia has allowed remarkable survivals in the course of accidental circulatory arrest. The selective application of mild hypothermia in severe traumatic brain injury is an area with promise. Deliberate circulatory arrest with hypothermic cerebral protection has also been used for seemingly unrepairable injuries and is the focus of ongoing research. PMID:10526517

  20. Neurologic Injury Associated with Rewarming from Hypothermia: Is Mild Hypothermia on Bypass Better than Deep Hypothermic Circulatory Arrest?

    PubMed Central

    Bhalala, Utpal S.; Appachi, Elumalai; Mumtaz, Muhammad Ali

    2016-01-01

    Many known risk factors for adverse cardiovascular and neurological outcomes in children with congenital heart defects (CHD) are not modifiable; however, the temperature and blood flow during cardiopulmonary bypass (CPB), are two risk factors, which may be altered in an attempt to improve long-term neurological outcomes. Deep hypothermic circulatory arrest, traditionally used for aortic arch repair, has been associated with short-term and long-term neurologic sequelae. Therefore, there is a rising interest in using moderate hypothermia with selective antegrade cerebral blood flow on CPB during aortic arch repair. Rewarming from moderate-to-deep hypothermia has been shown to be associated with neuronal injury, neuroinflammation, and loss of cerebrovascular autoregulation. A significantly lesser degree of rewarming is required following mild (33–35°C) hypothermia as compared with moderate (28–32°C), deep (21–27°C), and profound (less than 20°C) hypothermia. Therefore, we believe that mild hypothermia is associated with a lower risk of rewarming-induced neurologic injury. We hypothesize that mild hypothermia with selective antegrade cerebral perfusion during CPB for neonatal aortic arch repair would be associated with improved neurologic outcome. PMID:27734011

  1. Peripheral Adenosine A3 Receptor Activation Causes Regulated Hypothermia in Mice That Is Dependent on Central Histamine H1 Receptors.

    PubMed

    Carlin, Jesse Lea; Tosh, Dilip K; Xiao, Cuiying; Piñol, Ramón A; Chen, Zhoumou; Salvemini, Daniela; Gavrilova, Oksana; Jacobson, Kenneth A; Reitman, Marc L

    2016-02-01

    Adenosine can induce hypothermia, as previously demonstrated for adenosine A1 receptor (A1AR) agonists. Here we use the potent, specific A3AR agonists MRS5698, MRS5841, and MRS5980 to show that adenosine also induces hypothermia via the A3AR. The hypothermic effect of A3AR agonists is independent of A1AR activation, as the effect was fully intact in mice lacking A1AR but abolished in mice lacking A3AR. A3AR agonist-induced hypothermia was attenuated by mast cell granule depletion, demonstrating that the A3AR hypothermia is mediated, at least in part, via mast cells. Central agonist dosing had no clear hypothermic effect, whereas peripheral dosing of a non-brain-penetrant agonist caused hypothermia, suggesting that peripheral A3AR-expressing cells drive the hypothermia. Mast cells release histamine, and blocking central histamine H1 (but not H2 or H4) receptors prevented the hypothermia. The hypothermia was preceded by hypometabolism and mice with hypothermia preferred a cooler environmental temperature, demonstrating that the hypothermic state is a coordinated physiologic response with a reduced body temperature set point. Importantly, hypothermia is not required for the analgesic effects of A3AR agonists, which occur with lower agonist doses. These results support a mechanistic model for hypothermia in which A3AR agonists act on peripheral mast cells, causing histamine release, which stimulates central histamine H1 receptors to induce hypothermia. This mechanism suggests that A3AR agonists will probably not be useful for clinical induction of hypothermia.

  2. Peripheral Adenosine A3 Receptor Activation Causes Regulated Hypothermia in Mice That Is Dependent on Central Histamine H1 Receptors

    PubMed Central

    Carlin, Jesse Lea; Tosh, Dilip K.; Xiao, Cuiying; Piñol, Ramón A.; Chen, Zhoumou; Salvemini, Daniela; Gavrilova, Oksana; Jacobson, Kenneth A.

    2016-01-01

    Adenosine can induce hypothermia, as previously demonstrated for adenosine A1 receptor (A1AR) agonists. Here we use the potent, specific A3AR agonists MRS5698, MRS5841, and MRS5980 to show that adenosine also induces hypothermia via the A3AR. The hypothermic effect of A3AR agonists is independent of A1AR activation, as the effect was fully intact in mice lacking A1AR but abolished in mice lacking A3AR. A3AR agonist–induced hypothermia was attenuated by mast cell granule depletion, demonstrating that the A3AR hypothermia is mediated, at least in part, via mast cells. Central agonist dosing had no clear hypothermic effect, whereas peripheral dosing of a non–brain-penetrant agonist caused hypothermia, suggesting that peripheral A3AR-expressing cells drive the hypothermia. Mast cells release histamine, and blocking central histamine H1 (but not H2 or H4) receptors prevented the hypothermia. The hypothermia was preceded by hypometabolism and mice with hypothermia preferred a cooler environmental temperature, demonstrating that the hypothermic state is a coordinated physiologic response with a reduced body temperature set point. Importantly, hypothermia is not required for the analgesic effects of A3AR agonists, which occur with lower agonist doses. These results support a mechanistic model for hypothermia in which A3AR agonists act on peripheral mast cells, causing histamine release, which stimulates central histamine H1 receptors to induce hypothermia. This mechanism suggests that A3AR agonists will probably not be useful for clinical induction of hypothermia. PMID:26606937

  3. Chronic hypothermia in multiple sclerosis.

    PubMed Central

    Sullivan, F; Hutchinson, M; Bahandeka, S; Moore, R E

    1987-01-01

    Two patients with clinically definite multiple sclerosis presented with acute hypothermia and on recovery were found to be chronically hypothermic. Thermoregulatory studies indicated a central, hypothalamic defect which is presumed to be due to a plaque of demyelination. PMID:3612161

  4. Synergistic neuroprotective therapies with hypothermia

    PubMed Central

    Cilio, Maria Roberta; Ferriero, Donna M.

    2010-01-01

    summary Neuroprotection is a major health care priority, given the enormous burden of human suffering and financial cost caused by perinatal brain damage. With the advent of hypothermia as therapy for term hypoxic–ischemic encephalopathy, there is hope for repair and protection of the brain after a profound neonatal insult. However, it is clear from the published clinical trials and animal studies that hypothermia alone will not provide complete protection or stimulate the repair that is necessary for normal neurodevelopmental outcome. This review critically discusses drugs used to treat seizures after hypoxia–ischemia in the neonate with attention to evidence of possible synergies for therapy. In addition, other agents such as xenon, N-acetylcysteine, erythropoietin, melatonin and cannabinoids are discussed as future potential therapeutic agents that might augment protection from hypothermia. Finally, compounds that might damage the developing brain or counteract the neuroprotective effects of hypothermia are discussed. PMID:20207600

  5. Effects of hypothermia on skeletal ischemia reperfusion injury in rats

    PubMed Central

    Kaldırım, Ümit; Akyıldız, Faruk; Bilgiç, Serkan; Koca, Kenan; Poyrazoğlu, Yavuz; Uysal, Ozgür Selim; Turğut, Hasan; Türkkan, Selim; Erşen, Ömer; Topal, Turgut; Ozkan, Huseyin

    2015-01-01

    Objective The aim of this study was to investigate the effect of hypothermia (H) on skeletal ischemia-reperfusion (IR) injury in rats by measuring malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), nitric oxide (NO), and interleukin-1 beta (IL-1β) in muscle, and measureing immunohistochemical-inducible nitric oxide synthase (iNOS) staining of skeletal muscle. Materials and Methods Eighteen Wistar Albino rats were divided randomly into three groups (sham, IR, hypothermia) (n=6). The sham group had all procedures without the IR period. The lower right extremity of rats in the IR and hypothermia groups was subjected to 2 hours of ischemia and 22 hours of reperfusion by applying a clamp on the common iliac artery and a rubber-band at the level of the lesser trochanter under general anesthesia. Rats in the hypothermia group underwent 4 hours of hypothermia during the first four hours of reperfusion in addition to a 2-hour ischemia and 22-hour reperfusion period. All rats were sacrificed at end of the IR period using a high dose of anesthesia. The tibialis anterior muscles were preserved. Immunohistochemical iNOS staining was performed, and MDA, SOD, GSH-Px, NO, and IL-1β were measured in the muscle. Results The level of MDA, NO, and IL-1β in muscle was increased in the IR group compared with that in the sham group, but these parameters were decreased in the hypothermia group compared with the IR group. The activities of SOD and GSH-Px in muscle were decreased in the IR group; however, these parameters were increased in the hypothermia group. The score and intensity of iNOS staining of skeletal muscle was dens in IR group, mild in hypothermia group, and weak in sham group. Conclusion The present study has shown that hypothermia reduced IR injury in the skeletal muscle by decreasing the levels of MDA, NO, and IL-1β, and increasing the activities of SOD and GSH-Px. In addition, hypothermia attenuated the score and intensity of i

  6. Perioperative Hypothermia: Incidence and Prevention

    DTIC Science & Technology

    1990-01-01

    1990 Thesis/" Perioperative Hypothermia: Incidence and Prevention CRodney L. Fisher AFIT Student at: Columbia University AFIT/CI/CIA 90-120 AFT/I/I...Civilian Institution Programs DTIC CTELECTE 0 36 UNCLASSIFIFD 4 PERIOPERATIVE HYPOTHERMIA: INCIDENCE AND PREVENTION By Rodney L. Fisher, CAPT., USAF...Availability Codes Avall and/or Dit Special ABSTRACT Perioperative thermal regulation is discussed. A retrospective audit was conducted to identify the

  7. The effects of neonatal cryoanaesthesia-induced hypothermia on adult emotional behaviour and stress markers in C57BL/6 mice.

    PubMed

    Richter, S Helene; Wollmann, Eva; Schmidt, Michaela; Zillmann, Uwe; Hellweg, Rainer; Sprengel, Rolf; Gass, Peter

    2014-08-15

    Since the early 1930s, deep hypothermia (cryoanaesthesia) has been a useful anaesthetic in several types of surgery on neonatal rodents. Especially against the background of modern techniques in systems neuroscience, the method enjoys again increasing popularity. However, little is known about its effects on the subsequent adult behavioural and physiological profile. To systematically investigate the effects of neonatal cryoanaesthesia on adult basal and emotional behaviour as well as on physiological development, 59 C57BL/6 mouse pups were randomly assigned to one of three treatment groups: Pups of the first group were exposed to the hypothermia treatment (H) on postnatal day 3, while pups of the other two groups served as controls: These pups either remained in the home cage without any intervention (C), or were separated from the mother for 15 min (MS) to differentiate between effects of neonatal isolation alone versus hypothermia that inevitably goes along with neonatal isolation. Subsequent behavioural analyses were conducted during adulthood (P 84-P 130), including tests for exploratory, anxiety-like and depression-like behaviour. At the age of about 145 days mice were decapitated to record BDNF levels in the hippocampus and serum corticosterone. Altogether, H mice were found to display slightly increased anxiety levels on the O-Maze, but did not differ from the control animals in any other behavioural test. Subtle alterations in anxiety-like behaviour, however, were not accompanied by physiological changes in serum corticosterone and hippocampal BDNF levels, arguing against an overall long-lasting effect of neonatal hypothermia on the emotional profile of adult mice.

  8. Functional laser speckle imaging of cerebral blood flow under hypothermia

    NASA Astrophysics Data System (ADS)

    Li, Minheng; Miao, Peng; Zhu, Yisheng; Tong, Shanbao

    2011-08-01

    Hypothermia can unintentionally occur in daily life, e.g., in cardiovascular surgery or applied as therapeutics in the neurosciences critical care unit. So far, the temperature-induced spatiotemporal responses of the neural function have not been fully understood. In this study, we investigated the functional change in cerebral blood flow (CBF), accompanied with neuronal activation, by laser speckle imaging (LSI) during hypothermia. Laser speckle images from Sprague-Dawley rats (n = 8, male) were acquired under normothermia (37°C) and moderate hypothermia (32°C). For each animal, 10 trials of electrical hindpaw stimulation were delivered under both temperatures. Using registered laser speckle contrast analysis and temporal clustering analysis (TCA), we found a delayed response peak and a prolonged response window under hypothermia. Hypothermia also decreased the activation area and the amplitude of the peak CBF. The combination of LSI and TCA is a high-resolution functional imaging method to investigate the spatiotemporal neurovascular coupling in both normal and pathological brain functions.

  9. Pharmacological hypothermia: a potential for future stroke therapy?

    PubMed

    Liu, Kaiyin; Khan, Hajra; Geng, Xiaokun; Zhang, Jun; Ding, Yuchuan

    2016-06-01

    Mild physical hypothermia after stroke has been associated with positive outcomes. Despite the well-studied beneficial effects of hypothermia in the treatment of stroke, lack of precise temperature control, intolerance for the patient, and immunosuppression are some of the reasons which limit its clinical translation. Pharmacologically induced hypothermia has been explored as a possible treatment option following stroke in animal models. Currently, there are eight classes of pharmacological agents/agonists with hypothermic effects affecting a multitude of systems including cannabinoid, opioid, transient receptor potential vanilloid 1 (TRPV1), neurotensin, thyroxine derivatives, dopamine, gas, and adenosine derivatives. Interestingly, drugs in the TRPV1, neurotensin, and thyroxine families have been shown to have effects in thermoregulatory control in decreasing the compensatory hypothermic response during cooling. This review will briefly present drugs in the eight classes by summarizing their proposed mechanisms of action as well as side effects. Reported thermoregulatory effects of the drugs will also be presented. This review offers the opinion that these agents may be useful in combination therapies with physical hypothermia to achieve faster and more stable temperature control in hypothermia.

  10. Environmental hypothermia in porcine polytrauma and hemorrhagic shock is safe.

    PubMed

    Iyegha, Uroghupatei P; Greenberg, Joseph J; Mulier, Kristine E; Chipman, Jeffrey; George, Mark; Beilman, Greg J

    2012-10-01

    We have previously demonstrated survival benefit to induced hypothermia in a porcine model of controlled hemorrhagic shock simulating an associated delay to definitive care. In the current study, we wished to evaluate the effects of environmental hypothermia in a porcine model of hemorrhagic shock with the addition of polytrauma. Sixteen pigs were randomized to normothermic (39°C, n = 7) or hypothermic (34°C, n = 9) groups. The model included instrumentation, chest injury (captive bolt device), hemorrhage to systolic blood pressure (SBP) of ∼50 mmHg, and crush liver injury. Animals received limited fluid resuscitation for a 1-h period with goal SBP of greater than 80 mmHg and ice packs or warming blankets to achieve goal temperatures, followed by full resuscitation with goal SBP of greater than 90 mmHg, adequate urine output, and hemoglobin by protocol for 20 h. Survivors were observed for an additional 24 h with end points including mortality, markers of organ injury, and neurologic function. There were no differences in survival between the groups (mortality = 1/9, hypothermia group vs. 2/7, normothermia group, P = 0.39). Markers of organ injury were elevated in the hypothermia group at 24 h after injury but were identical between groups at the end of the experimental protocol (48 h after injury). There were no noted differences in neurologic function between the two groups. Environmental hypothermia in a model of polytrauma and hemorrhagic shock was not associated with worse outcomes.

  11. Hypothermia for pediatric refractory status epilepticus

    PubMed Central

    Guilliams, Kristin; Rosen, Max; Buttram, Sandra; Zempel, John; Pineda, Jose; Miller, Barbara; Shoykhet, Michael

    2014-01-01

    SUMMARY Purpose Refractory status epilepticus (RSE) is a life-threatening emergency, demonstrating, by definition, significant pharmacoresistance. We describe five cases of pediatric RSE treated with mild hypothermia. Methods Retrospective chart review was performed of records of children who received hypothermia for RSE at two tertiary-care pediatric hospitals between 2009 and 2012. Key Findings Five children with RSE received mild hypothermia (32–35°C). Hypothermia reduced seizure burden during and after treatment in all cases. Prior to initiation of hypothermia, four children (80%) received pentobarbital infusions to treat RSE, but relapsed after pentobarbital discontinuation. No child relapsed after treatment with hypothermia. One child died after redirection of care. Remaining four children were discharged. Significance This is the largest pediatric case series reporting treatment of RSE with mild hypothermia. Hypothermia decreased seizure burden during and after pediatric RSE and may prevent RSE relapse. PMID:23906244

  12. Hypothermia and physiological control: the respiratory system.

    PubMed

    Frappell, P

    1998-02-01

    1. Ventilation (VE) in unanaesthetized hypothermic animals remains tightly coupled to oxygen consumption (VO2) such that VE/VO2 remains constant despite changes in body temperature. 2. Ventilatory responses to hypoxia would suggest that, relative to metabolic rate, the gain of the respiratory system is unaltered in hypothermic animals. 3. Future studies should exercise care to ensure that the method applied in inducing hypothermia does not complicate ventilatory control and that the ability of the species to hibernate is taken into consideration.

  13. Hypothermia bed system for stroke patients. Technical note.

    PubMed

    Kawamura, S; Suzuki, E; Suzuki, A; Yasui, N

    1999-06-01

    A new hypothermia bed system was used to induce mild hypothermia (33-35 degrees C) in six patients with stroke due to subarachnoid hemorrhage, hypertensive intracerebral hemorrhage, or embolic internal carotid artery occlusion. The system bed contained all necessary equipment including a respirator, a cooling unit, physiological monitors, and a storage battery. Surface cooling of the patients was performed using water-circulating blankets, and core temperature was maintained based on bladder temperature and a feedback computer program. During hypothermic therapy, patient transfer and radiological examination including computed tomography and positron emission tomography could be easily and safely performed. Differences between the measured bladder temperature and the target temperature were approximately +/- 0.1 degree C. The proposed hypothermia system bed may be useful for serial radiological examination of patients with stroke.

  14. Inadvertent Perianesthetic Hypothermia in Small Animal Patients.

    PubMed

    Clark-Price, Stuart

    2015-09-01

    Inadvertent perianesthetic hypothermia is one of the most common complications in anesthesia of dogs and cats. Hypothermia during anesthesia can lead to altered pharmacokinetics of anesthetic and analgesic drugs, dysfunction of organ systems, increased patient susceptibility to infection, reduced wound healing, altered coagulation, hypotension, and delayed recovery. An understanding of the pathophysiology, complications, and techniques to minimize hypothermia during anesthesia can help veterinarians optimize care of patients. This article provides an overview of inadvertent perianesthetic hypothermia.

  15. Field Management of Accidental Hypothermia during Diving

    DTIC Science & Technology

    1990-01-01

    Case history number 97: Core rewarming by peritoneal irrigation in accidental hypothermia with cacdiac arrest. Anesth Analg 1966; 56:574-577. 85. Lint-n...Intractable ventricular fibrillation associated with profound accidental hypothermia - Successful treatment with ;irtial cardiopulmonary bypass . N Engl...5 B. CLINICAL ASSESSMENT OF THE HYPOTHERMIC DIVER ................ 6 C. FIELD TREATMENT OF HYPOTHERMIA. A REVIEW OF THE LITERATURE 9 D

  16. Adrenocortical response in rats subjected to a stress of restraint by immobilization whether accompanied by hypothermia or not

    NASA Technical Reports Server (NTRS)

    Buchel, L.; Prioux-Guyonneau, M.; Libian, L.

    1980-01-01

    The restraint associated with hypothermia which increases the adrenal activity in rats was investigated. In rats with nomothermia or light hypothermia, the plasma and adrenal corticosterone levels increase at least threefold whatever the duration of restraint. Their return to normal values depends on the duration of the restraint. Exposure to cold produces in free rats a light hypothermia with an increase of the plasma and adrenal corticosterone levels, and in restraint animals an important hypothermia which does not potentiate the stimulation of adrenocortical activity induced by the restraint alone.

  17. The Cold Blooded Killer: Hypothermia.

    ERIC Educational Resources Information Center

    Keller, Rosanne

    Part of a series of home literacy readers with conversational text and sketches, this booklet depicts the subarctic Alaskan environment where cold makes extreme demands on body metabolism. Body temperature must be maintained above 80F (26.7C). A condition of too little body-heat is termed hypo- ('deficit') thermia ('heat'). Hypothermia is the…

  18. Detrimental effect of hypothermia during acute normovolaemic haemodilution in anaesthetized cats

    NASA Astrophysics Data System (ADS)

    Talwar, A.; Fahim, Mohammad

    Haemodynamic responses to hypothermia were studied at normal haematocrit and following the induction of acute normovolaemic haemodilution. Experiments were performed on 20 cats anaesthetized with a mixture of chloralose and urethane in two groups. In one group (n=10) the effects of hypothermia on various haemodynamic variables were studied at normal haematocrit (41.0+/-1.7%) and in the second group of cats (n=10) the effects of hypothermia on various haemodynamic variables were studied after the induction of acute normovolaemic haemodilution (14.0+/-1.0%). The haemodynamic variables left ventricular pressure, left ventricular contractility, arterial blood pressure, heart rate and right atrial pressure were recorded on a polygraph. Cardiac output was measured using a cardiac output computer. In both groups hypothermia was induced by surface cooling with the help of ice. Cardiovascular variables were recorded at each 1° C fall in body temperature. Hypothermia produced a significant (P<0.05) drop in heart rate, cardiac output, arterial blood pressure and left ventricular contractility in both groups. However, the percentage decrease in these variables in response to hypothermia was significantly (P<0.05) higher in cats with low haematocrit than in those with normal haematocrit. The severity of hypothermia - induced cardiovascular effects is evident from the drastic decrease in heart rate, cardiac output, arterial blood pressure and myocardial contractility in cats with low haematocrit, indicating a higher risk of circulatory failure under anaemic conditions at low temperatures.

  19. Preventing Unplanned Perioperative Hypothermia in Children.

    PubMed

    Beedle, Susan E; Phillips, Amy; Wiggins, Shirley; Struwe, Leeza

    2017-02-01

    Unplanned perioperative hypothermia is a common surgical risk. Unplanned hypothermia is defined as a body temperature below 36° C (96.8° F) during any phase of the perioperative period. Perioperative nurses at a Midwestern tertiary pediatric hospital developed an evidence-based clinical practice guideline (CPG) designed to maintain normothermia for the pediatric surgical population. This CPG outlined standard thermoregulation nursing interventions and required the consistent use of a temporal artery thermometer. A test of this CPG before full implementation established a baseline incidence of unplanned hypothermia at 16.3% (n = 80). The purpose of this study was to measure the rate of perioperative hypothermia in children after implementing the evidence-based CPG. The study results demonstrated that the CPG, guiding research-based nursing practice, consistently prevented unplanned hypothermia. The incidence rate of unplanned perioperative hypothermia after CPG implementation was 1.84% (n = 1,196).

  20. Thermodynamic aspects of therapeutic hypothermia.

    PubMed

    Vanlandingham, Sean C; Kurz, Michael C; Wang, Henry E

    2015-01-01

    Therapeutic hypothermia (TH) is an important treatment for post-cardiac arrest syndrome. Despite its widespread practice, only limited data describe the thermodynamic aspects of heat transfer during TH. This paper reviews the principles of human body heat balance and provides a conceptual model for characterizing heat exchange during TH. The model may provide a framework for computer simulation for improving training in or clinical methods of TH.

  1. [Hypothermia--mechanism of action and pathophysiological changes in the human body].

    PubMed

    Sosnowski, Przemysław; Mikrut, Kinga; Krauss, Hanna

    2015-01-16

    This review focuses on the physiological responses and pathophysiological changes induced by hypothermia. Normal body function depends on its ability to maintain thermal homeostasis. The human body can be divided arbitrarily into two thermal compartments: a core compartment (trunk and head), with precisely regulated temperature around 37°C, and a peripheral compartment (skin and extremities) with less strictly controlled temperature, and lower than the core temperature. Thermoregulatory processes occur in three phases: afferent thermal sensing, central regulation, mainly by the preoptic area of the anterior hypothalamus, and efferent response. Exposure to cold induces thermoregulatory responses including cutaneous vasoconstriction, shivering and non-shivering thermogenesis, and behavioral changes. Alterations of body temperature associated with impaired thermoregulation, decreased heat production or increased heat loss can lead to hypothermia. Hypothermia is defined as a core body temperature below 35ºC, and may be classified according to the origin as accidental (e.g. caused by exposure to a cold environment, drugs, or illness) or intentional (i.e. therapeutic), or by the degree of hypothermia as mild, moderate or severe. Classification by temperature is not universal. Lowering of body temperature disrupts the physiological processes at the molecular, cellular and system level, but hypothermia induced prior to cardiosurgical or neurosurgical procedures, by the decrease in tissue oxygen demand, can reduce the risk of cerebral or cardiac ischemic damage. Therapeutic hypothermia has been recommended as a clinical procedure in situations characterized by ischemia, such as cardiac arrest, stroke and brain injuries.

  2. Therapeutic Hypothermia: What's Hot about Cold.

    PubMed

    Kerber, Richard E

    2011-01-01

    Reducing body temperature to 33 °C in patients who have been resuscitated from cardiac arrest but who remain comatose can ameliorate anoxic encephalopathy and improve recovery. Experimental animal studies have suggested that cooling to 33 °C also aids the resuscitative process itself, facilitating the resumption of spontaneous circulation (ROSC). The mechanism of cooling benefit is probably the reduction of metabolic demand of most organs, and reduced production of toxic metabolites and reactive oxygen species. External cooling by application of ice or pads through which cold water circulates is effective but requires up to 8 hours to achieve the target temperature of 33 °C. Our goal was to develop a faster method of cooling that could be initiated during cardiopulmonary resuscitation. In anesthetized swine, we induced ventricular fibrillation by passing alternating current down an electrode catheter in the right ventricle. We then ventilated the animals' lungs with liquid perfluorocarbons (PFCs), a technique known as total liquid ventilation (TLV). Perfluorocarbons are oxygen-carrying modules; we pre-oxygenated the PFCs by bubbling 100% O(2) through the solution for 2 minutes before use, and pre-cooled the PFCs to -15 °C. The cold oxygenated PFCs reduced pulmonary artery temperature (a surrogate for myocardial temperature) to 33 °C in about 6 minutes. Using this technique we achieved ROSC in 8 of 11 (82%) animals given TLV versus 3 of 11 (27%) control animals receiving conventional CPR without PFCs (P<0.05). We also compared the cold TLV technique with the administration of intravenous iced saline to achieve hypothermia. Both the cold TLV and cold saline techniques produced rapid hypothermia, but we could achieve ROSC in only 2 of 8 (25%) animals given cold saline versus 7 of 8 (88%) given cold TLV. This result is likely due to the rise in right atrial pressure and corresponding reduction in coronary perfusion pressure caused by volume loading with IV saline

  3. The cooling tube: A novel small animal model of systemic hypothermia in awake Syrian Golden Hamsters (mesocricetus auratus).

    PubMed

    Goedeke, Jan; Apelt, Nadja; Kamler, Markus

    2015-01-01

    Hypothermia is increasingly used as a therapeutic strategy in a diversity of clinical scenarios. Its impact on mammalian physiology, particularly on the microcirculatory changes of critical organ systems, are, however, incompletely understood. Close examination of the literature reveals a marked paucity of small animal models of rapid systemic hypothermia. All published models introduce important microvascular confounders by investigating either local cooling processes or using anaesthetised animals. Here we present the first rapid systemic hypothermia model in an awake hamster. We developed a waterstream cooled copper tube system for standardized systemic temperature control. With this novel system core body temperature (Tc) in 14 awake animals could be precisely stabilised at temperatures of 30°C and 18°C (7 animals, respectively) within 10-20 min. Rewarming was achieved over 10-15 min. Tolerance of the procedure was excellent. Hamsters did not show any behavioural changes in the mild hypothermia group. In the deep hypothermia group 6 of 7 animals regained normal behaviour within 2-11 hs. As hypothermia was induced in dorsal skinfold chamber bearing animals this model seems suitable for investigation of microcirculatory purposes.Advantages over previously established experimental hypothermia models are significant. Amongst these, the possibility of visualization of microcirculation, the lack of microcirculation confounding factors such as anaesthetic drugs, the ability for precise Tc control and rapid induction of hypothermia are prominent.

  4. Clinical and translational aspects of hypothermia in major trauma patients: from pathophysiology to prevention, prognosis and potential preservation.

    PubMed

    Søreide, Kjetil

    2014-04-01

    The human body strives at maintaining homeostasis within fairly tight regulated mechanisms that control vital regulators such as core body temperature, mechanisms of metabolism and endocrine function. While a wide range of medical conditions can influence thermoregulation the most common source of temperature loss in trauma patients includes: exposure (environmental, as well as cavitary), the administration of i.v. fluids, and anaesthesia/loss of shivering mechanisms, and blood loss per se. Loss of temperature can be classified either according to the aetiology (i.e. accidental/spontaneous versus trauma/haemorrhage-induced temperature loss), or according to an unintended, accidental induction in contrast to a medically intended therapeutic hypothermia. Hypothermia occurs infrequently (prevalence<10% of all injured), but more often (30-50%) in the severely injured. Hypothermia usually come together with and may aggravate acidosis and coagulopathy (the "lethal triad of trauma"), which again may be associated with a high mortality. However, recent studies disagree in the independent predictive role of hypothermia and mortality. Prevention of hypothermia is imperative through all phases of trauma care and must be an interest among all team members. Hypothermia in the trauma setting has attracted focus in the past from a pathophysiological, preventive and prognostic perspective; yet recent focus has shifted towards the potential for using hypothermia for pre-emptive and cellular protective purposes. This paper gives a brief update on some of the clinically relevant aspects of hypothermia in the injured patient.

  5. Food restriction alters N'-propyl-4,5,6,7-tetrahydrobenzothiazole-2,6-diamine dihydrochloride (pramipexole)-induced yawning, hypothermia, and locomotor activity in rats: evidence for sensitization of dopamine D2 receptor-mediated effects.

    PubMed

    Collins, Gregory T; Calinski, Diane M; Newman, Amy Hauck; Grundt, Peter; Woods, James H

    2008-05-01

    Food restriction enhances sensitivity to the reinforcing effects of a variety of drugs of abuse including opiates, nicotine, and psychostimulants. Food restriction has also been shown to alter a variety of behavioral and pharmacological responses to dopaminergic agonists, including an increased sensitivity to the locomotor stimulatory effects of direct- and indirect-dopamine agonists, elevated extracellular dopamine levels in responses to psychostimulants, as well as suppression of agonist-induced yawning. Behavioral and molecular studies suggest that augmented dopaminergic responses observed in food-restricted animals result from a sensitization of the dopamine D2 receptor; however, little is known about how food restriction affects dopamine D3 receptor function. The current studies were aimed at better defining the effects of food restriction on D2 and D3 receptor function by assessing the capacity of N'-propyl-4,5,6,7-tetrahydrobenzothiazole-2,6-diamine dihydrochloride (pramipexole) to induce yawning, penile erection (PE), hypothermia, and locomotor activity in free-fed and food-restricted rats. Food restriction resulted in a suppression of pramipexole-induced yawning, a sensitized hypothermic response, and an enhanced locomotor response to pramipexole, effects that are suggestive of an enhanced D2 receptor activity; no effect on pramipexole-induced PE was observed. Antagonist studies further supported a food restriction-induced enhancement of the D2 receptor activity because the D2 antagonist 3-[4-(4-chlorophenyl)-4-hydroxypiperidin-l-yl]methyl-1H-indole (L741,626) recovered pramipexole-induced yawning to free-fed levels, whereas yawning and PE were suppressed following pretreatment with the D3 antagonist N-{4-[4-(2,3-dichlorophenyl)-piperazin-1-yl]-trans-but-2-enyl}-4-pyridine-2-yl-benzamide hydrochloride (PG01037). The results of the current studies suggest that food restriction sensitized rats to the D2-mediated effects of pramipexole while having no effect

  6. Does induction time of mild hypothermia influence the survival duration of septic rats?

    PubMed

    Léon, Karelle; Pichavant-Rafini, Karine; Ollivier, Hélène; Monbet, Valérie; L'Her, Erwan

    2015-06-01

    The relationship between hypothermia induction time and survival duration following sepsis was studied on 31 male Sprague-Dawley rats (median weight 311 g, range 260-356 g). After anesthesia and when the target temperature was reached (normothermia: 38°C or mild induced hypothermia: 34°C), sepsis was induced by cecal ligation and perforation. Five experimental groups were used. In groups 1 and 2, temperature of septic rats was maintained throughout the experiment at 38°C (seven rats) or 34°C (six rats), respectively. In groups 3, 4, and 5, septic rats (six per group) were maintained at 38°C for 1, 2, and 3 hours, respectively, and then placed in mild hypothermia (34°C). For each group, the survival duration was determined and blood samples were performed at the tail to measure tumor necrosis factor-α (TNF-α) plasma concentration. Whatever the experimental group, a decrease in temperature from 38°C to 34°C significantly increased the survival duration of septic rats compared with those maintained at 38°C throughout the experiment. The delay between the onset of sepsis and induction of hypothermia was also crucial. Thus, hypothermia induced after 1 hour of sepsis at 38°C significantly increased the survival duration of septic rats (12 hours 37 minutes±1 hour 4 minutes; group 3) compared with hypothermia induced after 3 hours of sepsis (8 hours 56 minutes±1 h 20 minutes; group 5). Moreover, except for group 5, survival duration improvement of septic rats observed in hypothermia was related to a lower increase of TNF-α plasma concentration compared with septic rats in normothermia. During sepsis, mild induced hypothermia significantly increased the survival duration of septic rats. The earlier hypothermia was applied, the longer the septic rats survived. According to these results, hypothermia may therefore provide the necessary time to apply a proper treatment.

  7. Torpor and hypothermia: reversed hysteresis of metabolic rate and body temperature.

    PubMed

    Geiser, Fritz; Currie, Shannon E; O'Shea, Kelly A; Hiebert, Sara M

    2014-12-01

    Regulated torpor and unregulated hypothermia are both characterized by substantially reduced body temperature (Tb) and metabolic rate (MR), but they differ physiologically. Although the remarkable, medically interesting adaptations accompanying torpor (e.g., tolerance for cold and ischemia, absence of reperfusion injury, and disuse atrophy) often do not apply to hypothermia in homeothermic species such as humans, the terms "torpor" and "hypothermia" are often used interchangeably in the literature. To determine how these states differ functionally and to provide a reliable diagnostic tool for differentiating between these two physiologically distinct states, we examined the interrelations between Tb and MR in a mammal (Sminthopsis macroura) undergoing a bout of torpor with those of the hypothermic response of a similar-sized juvenile rat (Rattus norvegicus). Our data show that under similar thermal conditions, 1) cooling rates differ substantially (approximately fivefold) between the two states; 2) minimum MR is approximately sevenfold higher during hypothermia than during torpor despite a similar Tb; 3) rapid, endogenously fuelled rewarming occurs in torpor but not hypothermia; and 4) the hysteresis between Tb and MR during warming and cooling proceeds in opposite directions in torpor and hypothermia. We thus demonstrate clear diagnostic physiological differences between these two states that can be used experimentally to confirm whether torpor or hypothermia has occurred. Furthermore, the data can clarify the results of studies investigating the ability of physiological or pharmacological agents to induce torpor. Consequently, we recommend using the terms "torpor" and "hypothermia" in ways that are consistent with the underlying regulatory differences between these two physiological states.

  8. Moderate Hypothermia Significantly Decreases Hippocampal Cell Death Involving Autophagy Pathway after Moderate Traumatic Brain Injury.

    PubMed

    Jin, Yichao; Lin, Yingying; Feng, Jun-feng; Jia, Feng; Gao, Guo-yi; Jiang, Ji-yao

    2015-07-15

    Here, we evaluated changes in autophagy after post-traumatic brain injury (TBI) followed by moderate hypothermia in rats. Adult male Sprague-Dawley rats were randomly divided into four groups: sham injury with normothermia group (37 °C); sham injury with hypothermia group (32 °C); TBI with normothermia group (TNG; 37 °C); and TBI with hypothermia group (THG; 32 °C). Injury was induced by a fluid percussion TBI device. Moderate hypothermia (32 °C) was achieved by partial immersion in a water bath (0 °C) under general anesthesia for 4 h. All rats were killed at 24 h after fluid percussion TBI. The ipsilateral hippocampus in all rats was analyzed with hematoxylin and eosin staining; terminal deoxynucleoitidyl transferase-mediated nick end labeling staining was used to determine cell death in ipsilateral hippocampus. Immunohistochemistry and western blotting of microtubule-associated protein light chain 3 (LC3), Beclin-1, as well as transmission electron microscopy performed to assess changes in autophagy. At 24 h after TBI, the cell death index was 27.90 ± 2.36% in TNG and 14.90 ± 1.52% in THG. Expression level of LC3 and Beclin-1 were significantly increased after TBI and were further up-regulated after post-TBI hypothermia. Further, ultrastructural observations showed that there was a marked increase of autophagosomes and autolysosomes in ipsilateral hippocampus after post-TBI hypothermia. Our data demonstrated that moderate hypothermia significantly attenuated cell death and increased autophagy in ipsilateral hippocampus after fluid percussion TBI. In conclusion, autophagy pathway may participate in the neuroprotective effect of post-TBI hypothermia.

  9. Moderate Hypothermia Significantly Decreases Hippocampal Cell Death Involving Autophagy Pathway after Moderate Traumatic Brain Injury

    PubMed Central

    Jin, Yichao; Lin, Yingying; Feng, Jun-feng; Jia, Feng; Gao, Guo-yi

    2015-01-01

    Abstract Here, we evaluated changes in autophagy after post-traumatic brain injury (TBI) followed by moderate hypothermia in rats. Adult male Sprague-Dawley rats were randomly divided into four groups: sham injury with normothermia group (37°C); sham injury with hypothermia group (32°C); TBI with normothermia group (TNG; 37°C); and TBI with hypothermia group (THG; 32°C). Injury was induced by a fluid percussion TBI device. Moderate hypothermia (32°C) was achieved by partial immersion in a water bath (0°C) under general anesthesia for 4 h. All rats were killed at 24 h after fluid percussion TBI. The ipsilateral hippocampus in all rats was analyzed with hematoxylin and eosin staining; terminal deoxynucleoitidyl transferase-mediated nick end labeling staining was used to determine cell death in ipsilateral hippocampus. Immunohistochemistry and western blotting of microtubule-associated protein light chain 3 (LC3), Beclin-1, as well as transmission electron microscopy performed to assess changes in autophagy. At 24 h after TBI, the cell death index was 27.90±2.36% in TNG and 14.90±1.52% in THG. Expression level of LC3 and Beclin-1 were significantly increased after TBI and were further up-regulated after post-TBI hypothermia. Further, ultrastructural observations showed that there was a marked increase of autophagosomes and autolysosomes in ipsilateral hippocampus after post-TBI hypothermia. Our data demonstrated that moderate hypothermia significantly attenuated cell death and increased autophagy in ipsilateral hippocampus after fluid percussion TBI. In conclusion, autophagy pathway may participate in the neuroprotective effect of post-TBI hypothermia. PMID:25942484

  10. Influence of cooling rate on activity of ionotropic glutamate receptors in brain slices at hypothermia.

    PubMed

    Mokrushin, Anatoly A; Pavlinova, Larisa I; Borovikov, Sergey E

    2014-08-01

    Hypothermia is a known approach in the treatment of neurological pathologies. Mild hypothermia enhances the therapeutic window for application of medicines, while deep hypothermia is often accompanied by complications, including problems in the recovery of brain functions. The purpose of present study was to investigate the functioning of glutamate ionotropic receptors in brain slices cooled with different rates during mild, moderate and deep hypothermia. Using a system of gradual cooling combined with electrophysiological recordings in slices, we have shown that synaptic activity mediated by the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and N-methyl-D-aspartate receptors in rat olfactory cortex was strongly dependent on the rate of lowering the temperature. High cooling rate caused a progressive decrease in glutamate receptor activity in brain slices during gradual cooling from mild to deep hypothermia. On the contrary, low cooling rate slightly changed the synaptic responses in deep hypothermia. The short-term potentiation may be induced in slices by electric tetanization at 16 °C in this case. Hence, low cooling rate promoted preservation of neuronal activity and plasticity in the brain tissue.

  11. [Fundus hypothermia at 29 degrees C prevents ischemic injury of the outer retina].

    PubMed

    Mori, K; Hayashi, N; Abe, T; Yoneya, S

    1995-09-01

    We evaluated quantitatively the protective effect of local fundus hypothermia under pressure-induced ischemia using morphometric analysis. Retinochoroidal ischemia was produced in albino rabbit eyes by increasing the intraocular pressure for 60 minutes. During the ischemic procedure, a copper plate was inserted behind the eyeball. The retinal temperature in the posterior pole was thus reduced to 29 degrees C by placing solid carbon dioxide, and to 32 degrees C by placing an ice cube at the anterior end of the plate. Histopathological changes in the group with ischemia alone were obvious in visual cells and retinal pigment epithelial cells (RPE), but the retina treated with additional hypothermia was well preserved. In the retina with hypothermia at 29 degrees C, there was no significant difference from the controls in the mean thickness of the photoreceptor layer (PRL) and the RPE, and the average count of nuclei in the outer nuclear layer (ONL). In the retina with hypothermia at 32 degrees C, there was also no significant difference from the controls in the thickness of the PRL and the RPE. Otherwise, the count of nuclei in the ONL decreased significantly when compared to that of controls (p < 0.001). These findings indicate that even mild hypothermia at 29 degrees C preserves the outer retina from ischemic damage and that the protective effect of hypothermia at 32 degrees C is insufficient.

  12. Regional and time-dependent neuroprotective effect of hypothermia following oxygen-glucose deprivation.

    PubMed

    Allard, Justine; Paci, Paula; Vander Elst, Luce; Ris, Laurence

    2015-02-01

    The neuroprotective effect of hypothermia has been demonstrated in in vivo and in vitro models of cerebral ischemia. In regard to the hippocampus, previous studies have mainly focused on CA1 pyramidal neurons, which are very vulnerable to ischemia. But the dentate gyrus (DG), in which neuronal proliferation occurs, can also be damaged by ischemia. In this study, we explored the neuroprotective effect of postischemic hypothermia in different areas of the hippocampus after mild or severe ischemia. Organotypic hippocampal slice cultures were prepared from 6- to 8-day-old rats and maintained for 12 days. Cultures were exposed to 25 or 35 min of oxygen and glucose deprivation (OGD). Neuronal damage was quantified after 6, 24, 48, and 72 h by propidium iodide fluorescence. Mild hypothermia (33°C) was induced 1 h after the end of OGD and was maintained for a period of 24 h. Short OGD produced delayed neuronal damage in the CA1 area and in the DG and to a lesser extend in the CA3 area. Damage in CA1 pyramidal cells was totally prevented by hypothermia whereas neuroprotection was limited in the DG. Thirty-five-minute OGD induced more rapid and more severe cell death in the three regions. In this case, hypothermia induced 1 h after OGD was unable to protect CA1 pyramidal cells whereas hypothermia induced during OGD was able to prevent cell loss. This study provides evidence that neuroprotection by hypothermia is limited to specific areas and depends on the severity of the ischemia.

  13. [Perioperative hypothermia. Impact on wound healing].

    PubMed

    Pietsch, A P; Lindenblatt, N; Klar, E

    2007-09-01

    Mild perioperative hypothermia is a common complication of anesthesia and surgery associated with several adverse effects including impaired wound healing and more frequently leads to wound infections. Perioperative hypothermia affects the hemostasis and various immune functions and therefore interferes with the initial phases of the wound healing process. Furthermore, perioperative hypothermia contributes to wound complications by inhibition of deposition of collagen and prolongation of postoperative catabolism. Wound complications prolong hospitalization and substantially increase medical costs. Thus, maintaining normothermia perioperatively is essential to reduce the number of wound complications.

  14. Mild hypothermia alleviates brain oedema and blood-brain barrier disruption by attenuating tight junction and adherens junction breakdown in a swine model of cardiopulmonary resuscitation

    PubMed Central

    Li, Jiebin; Li, Chunsheng; Yuan, Wei; Wu, Junyuan; Li, Jie; Li, Zhenhua; Zhao, Yongzhen

    2017-01-01

    Mild hypothermia improves survival and neurological recovery after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). However, the mechanism underlying this phenomenon is not fully elucidated. The aim of this study was to determine whether mild hypothermia alleviates early blood–brain barrier (BBB) disruption. We investigated the effects of mild hypothermia on neurologic outcome, survival rate, brain water content, BBB permeability and changes in tight junctions (TJs) and adherens junctions (AJs) after CA and CPR. Pigs were subjected to 8 min of untreated ventricular fibrillation followed by CPR. Mild hypothermia (33°C) was intravascularly induced and maintained at this temperature for 12 h, followed by active rewarming. Mild hypothermia significantly reduced cortical water content, decreased BBB permeability and attenuated TJ ultrastructural and basement membrane breakdown in brain cortical microvessels. Mild hypothermia also attenuated the CPR-induced decreases in TJ (occludin, claudin-5, ZO-1) and AJ (VE-cadherin) protein and mRNA expression. Furthermore, mild hypothermia decreased the CA- and CPR-induced increases in matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF) expression and increased angiogenin-1 (Ang-1) expression. Our findings suggest that mild hypothermia attenuates the CA- and resuscitation-induced early brain oedema and BBB disruption, and this improvement might be at least partially associated with attenuation of the breakdown of TJ and AJ, suppression of MMP-9 and VEGF expression, and upregulation of Ang-1 expression. PMID:28355299

  15. MicroRNA-155 potentiates the inflammatory response in hypothermia by suppressing IL-10 production.

    PubMed

    Billeter, Adrian T; Hellmann, Jason; Roberts, Henry; Druen, Devin; Gardner, Sarah A; Sarojini, Harshini; Galandiuk, Susan; Chien, Sufan; Bhatnagar, Aruni; Spite, Matthew; Polk, Hiram C

    2014-12-01

    Therapeutic hypothermia is commonly used to improve neurological outcomes in patients after cardiac arrest. However, therapeutic hypothermia increases sepsis risk and unintentional hypothermia in surgical patients increases infectious complications. Nonetheless, the molecular mechanisms by which hypothermia dysregulates innate immunity are incompletely understood. We found that exposure of human monocytes to cold (32°C) potentiated LPS-induced production of TNF and IL-6, while blunting IL-10 production. This dysregulation was associated with increased expression of microRNA-155 (miR-155), which potentiates Toll-like receptor (TLR) signaling by negatively regulating Ship1 and Socs1. Indeed, Ship1 and Socs1 were suppressed at 32°C and miR-155 antagomirs increased Ship1 and Socs1 and reversed the alterations in cytokine production in cold-exposed monocytes. In contrast, miR-155 mimics phenocopied the effects of cold exposure, reducing Ship1 and Socs1 and altering TNF and IL-10 production. In a murine model of LPS-induced peritonitis, cold exposure potentiated hypothermia and decreased survival (10 vs. 50%; P < 0.05), effects that were associated with increased miR-155, suppression of Ship1 and Socs1, and alterations in TNF and IL-10. Importantly, miR-155-deficiency reduced hypothermia and improved survival (78 vs. 32%, P < 0.05), which was associated with increased Ship1, Socs1, and IL-10. These results establish a causal role of miR-155 in the dysregulation of the inflammatory response to hypothermia.

  16. Hypothermia

    MedlinePlus

    ... abdominal cavity (peritoneal cavity). Staying warm in cold weather Before you or your children step out into cold air, remember the advice that follows with the simple acronym COLD — cover, overexertion, layers, dry: Cover. Wear a hat or other protective covering ...

  17. Hypothermia

    MedlinePlus

    ... not possible, get the person out of the wind and use a blanket to provide insulation from ... protect your body. These include: Mittens (not gloves) Wind-proof, water-resistant, many-layered clothing Two pairs ...

  18. Prevention of perioperative hypothermia in plastic surgery.

    PubMed

    Young, V Leroy; Watson, Marla E

    2006-01-01

    While inadvertent perioperative hypothermia has received serious attention in many surgical specialties, few discussions of hypothermia have been published in the plastic surgery literature. This article reviews the physiology of thermoregulation, describes how both general and regional anesthesia alter the normal thermoregulatory mechanisms, indicates risk factors particularly associated with hypothermia, and discusses the most effective current methods for maintaining normothermia. Hypothermia is typically defined as a core body temperature of /=36.5 degrees C is maintained. Unless preventive measures are instituted, inadvertent hypothermia occurs in 50% to 90% of surgical patients, even those undergoing relatively short procedures lasting one to one-and-a-half hours. During either general or regional anesthesia, a patient's natural behavioral and autonomic responses to cold are unavailable or impaired, and the combination of general and neuraxial anesthesia produces the highest risk for inadvertent perioperative hypothermia. Unless hypothermia is prevented, the restoration of normothermia can take more than 4 hours once anesthesia is stopped. Consequences of hypothermia are serious and affect surgical outcomes in plastic surgery patients. Potential complications include morbid cardiac events, coagulation disorders and blood loss, increased incidence of surgical wound infection, postoperative shivering, longer hospital stays, and increased costs associated with surgery. Measures for preventing hypothermia are emphasized in this article, especially those proven most effective in prospective and controlled clinical studies. Perhaps the most important step in maintaining normothermia is to prewarm patients in the preoperative area with forced-air heating systems. Intraoperative warming with forced-air and fluid warming are also essential. Other strategies

  19. [Recent treatment of postischaemic anoxic brain damage after cardiac arrest by using therapeutic hypothermia].

    PubMed

    Andjelić, Sladjana

    2008-01-01

    Organ injury caused by ischaemia and anoxia during prolonged cardiac arrest is compounded by reperfusion injury that occurs when spontaneous circulation is restored. Mild hypothermia (32-35 degrees C) is neuroprotective through several mechanisms, including suppression of apoptosis, reduced production of excitotoxins and free radicals, and anti-inflammatory actions. Experimental studies show that hypothermia is more effective the earlier it is started after return of spontaneous circulation (ROSC). Two randomised clinical trials show improved survival and neurological outcome in adults who remained comatose after initial resuscitation from prehospital VF cardiac arrest, and who were cooled after ROSC. Different strategies can be used to induce hypothermia. Optimal timing of therapeutic hypothermia for cardiac ischaemia is unknown. In patients who failed to respond to standard cardiopulmonary resuscitation, intra-arrest cooling using ice-cold intravenous (i.v.) fluid improved the chance of survival. Recently, fasudil, a Rho kinase inhibitor, was reported to prevent cerebral ischaemia in vivo by increasing cerebral blood flow and inhibiting inflammatory responses. In future, two different kinds of protective therapies, BCL-2 overexpression and hypothermia,will both inhibit aspects of apoptotic cell death cascades, and that combination treatment can prolong the temporal "therapeutic window" for gene therapy.

  20. Neuroprotective effect of epidural hypothermia after spinal cord lesion in rats

    PubMed Central

    Barbosa, Marcello Oliveira; Cristante, Alexandre Fogaça; dos Santos, Gustavo Bispo; Ferreira, Ricardo; Marcon, Raphael Martus; de Barros Filho, Tarcisio Eloy Pessoa

    2014-01-01

    OBJECTIVES : To evaluate the neuroprotective effect of epidural hypothermia in rats subjected to experimental spinal cord lesion. METHODS: Wistar rats (n = 30) weighing 320-360 g were randomized to two groups (hypothermia and control) of 15 rats per group. A spinal cord lesion was induced by the standardized drop of a 10-g weight from a height of 2.5 cm, using the New York University Impactor, after laminectomy at the T9-10 level. Rats in the hypothermia group underwent epidural hypothermia for 20 minutes immediately after spinal cord injury. Motor function was assessed for six weeks using the Basso, Beattie and Bresnahan motor scores and the inclined plane test. At the end of the final week, the rats' neurological status was monitored by the motor evoked potential test and the results for the two groups were compared. RESULTS: Analysis of the Basso, Beattie and Bresnahan scores obtained during the six-week period indicated that there were no significant differences between the two groups. There was no significant difference between the groups in the inclined plane test scores during the six-week period. Furthermore, at the end of the study, the latency and amplitude values of the motor evoked potential test were not significantly different between the two groups. CONCLUSION: Hypothermia did not produce a neuroprotective effect when applied at the injury level and in the epidural space immediately after induction of a spinal cord contusion in Wistar rats. PMID:25141116

  1. [Hypothermia due to anti-tuberculosis drugs: first case].

    PubMed

    Oualil, H; Nejjari, S; Bourkadi, J E; Iraqi, G

    2014-10-01

    Hypothermia - an adverse reaction of drug use potentially severe - requires an early diagnosis and an adapted management. We report the first case, to our knowledge of hypothermia due to anti-tuberculosis drugs.

  2. Effect of enhanced geomagnetic activity on hypothermia and mortality in rats

    NASA Astrophysics Data System (ADS)

    Bureau, Y. R. J.; Persinger, M. A.; Parker, G. H.

    1996-12-01

    The hypothesis was investigated that variability in the severity of limbic seizure-induced hypothermia in rats was affected by ambient geomagnetic activity. Data were obtained in support of this hypothesis. The depth of the hypothermia was significantly ( P < 0.001) reduced if the ambient geomagnetic activity exceeded 35 nT to 40 nT. Mortality during the subsequent 5 days was increased when the geomagnetic activity was > 20 nT. The magnitude of the effect was comparable to the difference between exposure to light or to darkness during the 20 h after the induction of limbic seizures.

  3. Hypothermia secondary to glioblastoma multiforme? Autopsy findings in two cases.

    PubMed

    Morgan, Matthew; Schwartz, Liliana; Duflou, Johan

    2015-03-01

    Death due to accidental primary hypothermia in cold climates is relatively common, with previous case series reflecting this. In contrast, hypothermia-related death as a result of an underlying medical cause, such as a brain tumor, is rare. The literature clearly illustrates a theoretical causal relationship between brain neoplasms and hypothermia through the infiltration of the hypothalamus; however, the number of reported cases is minimal. Two cases are presented where autopsy confirmed hypothermia as the cause of death with both cases revealing widespread glioblastoma multiforme in the brain. Both decedents were elderly with a number of comorbidities identified during autopsy that could explain death; however, hypothermia was deemed the most likely cause. It is proposed that both decedents died of hypothermia as a result of the tumor's effect on thermoregulation. These cases underline the importance of forensic pathologists to be aware of the relationship between brain tumors and hypothermia and to not dismiss death as being due to other disease processes.

  4. A preliminary study on determining the time window of hypothermia cerebral protection in rat cortex by laser speckle flowmetry

    NASA Astrophysics Data System (ADS)

    Wang, Wenjia; Li, Qiang; Zeng, Shaoqun; Luo, Qingming; Li, Pengcheng

    2007-02-01

    Laser speckle imaging technique was used to characterize the spatiotemporal changes in cerebral blood flow (CBF) in rat cortex induced by the local ultraprofound hypothermia(0°C) with the duration time of 1 min, 2 min, 5 min, 7 min and 10 min. The experimental results showed significant difference of the spatiotemporal characteristics of changes in CBF between short term and long term of ultraprofound hypothermia. For the short duration of ultraprofound hypothermia (1 min, 2 min and 5 min), the hypothermia cause the CBF decrease firstly, and then the CBF increase rapidly when the temperature is recovered to 37°C, exceeding the baseline level and lasting 10+/-3 min, finally return to the baseline. This trend of changes in CBF is similar in the regions of artery, vein and parenchyma, but with different amplitude. For the duration time of 7 min, the changes in CBF also exhibit the similar decrease induced by ultraprofound hypothermia and the rapid increase induced by the temperature recovering, however the increase does not show the overshoot, but only reach around 75% of the baseline level. For the duration of 10 min of ultraprofound hypothermia, the CBF does not increase rapidly when the temperature is recovered to 37°C, but remains at the low level of CBF for 12+/-2 min, and then increases gradually at artery sites, or increases rapidly and then decrease slightly later at the vein and parenchyma sites. Similar as the case in the duration time of 7 min, the final CBF only recovers to about 75% of the baseline level. The experimental results suggest that the CBF can not recover to the baseline after a long duration of ultraprofound hypothermia longer than 7 min.

  5. Hypothermia and the Elderly: Perceptions and Behaviors.

    ERIC Educational Resources Information Center

    Avery, Carol E.; Pestle, Ruth E.

    1987-01-01

    Interviewed 381 older adults participating in Area Agency on Aging meal programs in Florida. Found that only 10 percent were aware of dangers of accidental hypothermia. Many low-income elderly are vulnerable to cold because of poorly insulated homes, inadequate heating, and lack of warm clothing. States need initiatives to increase comfort levels…

  6. Effects of mild (33 degrees C) and moderate (29 degrees C) hypothermia on cerebral blood flow and metabolism, lactate, and extracellular glutamate in experimental head injury.

    PubMed

    Mori, K; Maeda, M; Miyazaki, M; Iwase, H

    1998-12-01

    The effects of mild (33 degrees C) and moderate (29 degrees C) hypothermia were investigated to determine which temperature was more effective against compression-induced cerebral ischemia. Eighteen cats were anesthetized. The animals were divided into three groups according to deep-brain temperature (control, 37 degrees C; mild hypothermia, 33 degrees C; and moderate hypothermia, 29 degrees C). Intracranial pressure (ICP) and cerebral blood flow (CBF) were monitored, the latter by hydrogen clearance. Arteriovenous oxygen difference (AVDO2) and cerebral venous oxygen saturation (ScvO2) were measured in blood samples from the superior sagittal sinus. The cerebral metabolic rate of oxygen (CMRO2) and the cerebral metabolic rate of lactate (CMR lactate) were calculated. Extracellular glutamate was measured by microdialysis. ICP was increased by inflation of an epidural balloon until CBF became zero, and this ischemia was maintained for 5 min, after which the balloon was quickly deflated. All parameters were recorded over 6 h. Evans blue was injected to examine vascular permeability changes. CBF was decreased by 56% by mild hypothermia and by 77% by moderate hypothermia. Mild hypothermia had a coupled metabolic suppression whereas moderate hypothermia significantly increased AVDO2 and decreased ScvO2, producing a low CBF/CMRO2 (relative ischemia). After balloon deflation, all three groups showed reactive hyperemia, which was significantly reduced by mild and moderate hypothermia. CBF then decreased to 50% of pre-inflation values and ScvO2 decreased (post-ischemic hypoperfusion). CBF/CMRO2, ScvO2, and AVDO2 did not differ significantly between the three groups. After balloon deflation, all three groups showed increased CMR lactate, which was significantly reduced by mild and moderate hypothermia. Extracellular glutamate increased in control animals (3.8 +/- 1.72 microM), an effect most effectively suppressed in the mild hypothermia group (1.0 +/- 0.46 microM). Damaged

  7. Hypothermia and neurological outcome after cardiac arrest: state of the art.

    PubMed

    Polderman, K H

    2008-01-01

    Multi-centred studies in patients who remain comatose after cardiac arrest and also in newborn babies with perinatal asphyxia have clearly demonstrated that mild hypothermia (32-34 degrees C) can improve neurological outcome after post-anoxic injury. This represents a highly promising development in the field of neurocritical care. This review discusses the place of mild therapeutic hypothermia in the overall therapeutic strategy for cardiac arrest patients. Cooling should not be viewed in isolation but in the context of a 'treatment bundle,' which together can significantly improve outcome after cardiac arrest. Favourable outcomes of 50-60% are now routinely achieved in many centres in patients with witnessed arrest and an initial rhythm of ventricular fibrillation or ventricular tachycardia. These results have been achieved by combining a number of therapeutic strategies, including early and effective resuscitation with greater emphasis on continuing chest compressions throughout various procedures (including resumption of compressions immediately after defibrillation even if rhythm has been restored) as well as prevention of hypoxia and hypotension in all stages following restoration of spontaneous circulation. Regarding the use of hypothermia, early induction and proper management of side-effects are the key elements of successful implementation. Treatment should include the rapid infusion of 1500-3000 mL of cold fluids to induce hypothermia and prevent hypovolaemia and hypotension. Educational activities to increase awareness and acceptance of new therapeutic options and European Resuscitation Council guidelines are urgently required.

  8. Hypometabolism and hypothermia in the rat model of endotoxic shock: independence of circulatory hypoxia

    PubMed Central

    Corrigan, Joshua J; Fonseca, Monique T; Flatow, Elizabeth A; Lewis, Kevin; Steiner, Alexandre A

    2014-01-01

    We tested the hypothesis that development of hypothermia instead of fever in endotoxic shock is consequential to hypoxia. Endotoxic shock was induced by bacterial lipopolysaccharide (LPS, 500 μg kg−1 i.v.) in rats at an ambient temperature of 22°C. A β3-adrenergic agonist known to activate metabolic heat production, CL316,243, was employed to evaluate whether thermogenic capacity could be impaired by the fall in oxygen delivery () during endotoxic shock. This possibility was rejected as CL316,243 (0.15 mg kg−1 i.v.) evoked similar rises in oxygen consumption () in the presence and absence of endotoxic shock. Next, to investigate whether a less severe form of circulatory hypoxia could be triggering hypothermia, the circulating volume of LPS-injected rats was expanded using 6% hetastarch with the intention of improving tissue perfusion and alleviating hypoxia. This intervention attenuated not only the fall in arterial pressure induced by LPS, but also the associated falls in and body temperature. These effects, however, occurred independently of hypoxia, as they were not accompanied by any detectable changes in NAD+/NADH ratios. Further experimentation revealed that even the earliest drops in cardiac output and during endotoxic shock did not precede the reduction in that brings about hypothermia. In fact, and fell in such a synchrony that the / ratio remained unaffected. Only when hypothermia was prevented by exposure to a warm environment (30°C) did an imbalance in the / ratio become evident, and such an imbalance was associated with reductions in the renal and hypothalamic NAD+/NADH ratios. In conclusion, hypometabolism and hypothermia in endotoxic shock are not consequential to hypoxia but serve as a pre-emptive strategy to avoid hypoxia in this model. PMID:24951620

  9. [Management of peri-operative hypothermia].

    PubMed

    Fernández-Meré, L A; Alvarez-Blanco, M

    2012-01-01

    Hypothermia (body temperature under 36°C) is the thermal disorder most frequently found in surgical patients, but should be avoided as a means of reducing morbidity and costs. Temperature should be considered as a vital sign and all staff involved in the care of surgical patients must be aware that it has to be maintained within normal limits. Maintaining body temperature is the result, as in any other system, of the balance between heat production and heat loss. Temperature regulation takes place through a system of positive and negative feedback in the central nervous system, being developed in three phases: thermal afferent, central regulation and efferent response. Prevention is the best way to ensure a normal temperature. The active warming of the patient during surgery is mandatory. Using warm air is the most effective, simple and cheap way to prevent and treat hypothermia.

  10. Heat Capacity, Body Temperature, and Hypothermia

    NASA Astrophysics Data System (ADS)

    Kimbrough, Doris R.

    1998-01-01

    Even when air and water are at the same temperature, water will "feel" distinctly colder to us. This difference is due to the much higher heat capacity of water than of air. Offered here is an interesting life science application of water's high heat capacity and its serious implications for the maintenance of body temperature and the prevention of hypothermia in warm-blooded animals.

  11. Devices for Emergency Hypothermia and Military Applications

    DTIC Science & Technology

    2004-09-01

    Research (SCRR) shows excellent results. Part of the SCRR work is based on induction of mild-moderate or profound hypothermia (SA) in laboratory animals...and a secondary heat exchanger. The secondary, which is part of a disposable tubing set, must be sterlilzable and heparin bondable. Existing heat...controller output. -T,(S) T,(s) Controller _C(s).T Plant 4 -Ts Gs Scaler PS Gss) - T(S) FIGURE 1. GENERALIZED BLOCK DIAGRAM OF CONTROL SYSTEM The

  12. [Prolonged hypothermia in refractory intracranial hypertension. Report of one case].

    PubMed

    Rovegno, Maximiliano; Valenzuela, José Luis; Mellado, Patricio; Andresen, Max

    2012-02-01

    The use of hypothermia after cardiac arrest caused by ventricular fibrillation is a standard clinical practice, however its use for neuroprotection has been extended to other conditions. We report a 23-year-old male with intracranial hypertension secondary to a parenchymal hematoma associated to acute hydrocephalus. An arterial malformation was found and embolized. Due to persistent intracranial hypertension, moderate hypothermia with a target temperature of 33°C was started. After 12 hours of hypothermia, intracranial pressure was controlled. After 13 days of hypothermia a definitive control of intracranial pressure was achieved. The patient was discharged 40 days after admission, remains with a mild hemiparesia and is reassuming his university studies.

  13. Delayed combination therapy of local brain hypothermia and decompressive craniectomy on acute stroke outcome in rat

    PubMed Central

    Allahtavakoli, Mohammad; Kahnouei, Mohammadamin Hosseini; Rezazadeh, Hossein; Roohbakhsh, Ali; Mahmoodi, Mohammad Hossein; Moghadam-Ahmadi, Amir; Zarisfi, Mohammadreza

    2014-01-01

    Objective(s): Hypothermia and decompressive craniectomy (DC) have been shown to be neuroprotective. This study was designed to evaluate neuroprotective effects of delayed singular or combination of DC and local hypothermia on stroke. Materials and Methods: Cerebral ischemia was induced in 48 Wistar rats assigned to 4 groups: control, decompressive craniectomy (DC), local hypothermia (LH), combination of hypothermia and craniectomy (HC). Infarct size and BBB disruption were measured 48 hr after ischemia insult. Neurological deficits were assessed at 24 and 48 hr after stroke by using sticky tape test, hanging-wire test and Bederson’s scoring system. BBB disruption was measured by Evans blue dye leakage. Results: Although infarct size was significantly reduced in LH, DC and HC groups (P<0.001), combination therapy was more neuroprotective compared to craniectomy alone (P<0.01). BBB disruption was significantly reduced in DC (P< 0.05) and LH and HC (P< 0.01).While sticky tape test (P<0.05 at 24 hr; P<0.001 at 48 hr) and hanging-wire test (P<0.05) showed better behavioral performance only in HC, Bederson test showed improved behavioral functions of both LH (P<0.05 at 24 hr and P<0.01 at 48 hr) and HC animals (P<0.01). Neurological deficits were also decreased in LH (P<0.05) or HC (P<0.05 at 24 hr; P<0.01 at 48 hr) groups compared to the DC group at the same time. Conclusion: Based on our data, although both delayed local hypothermia and craniectomy are protective after stoke, combination therapy of them is more neuroprotective than given alone. PMID:25429337

  14. [Experiences with transparenchymal coral calculi removal under local hypothermia].

    PubMed

    Albert, L; Zacher, W; Meyer, S

    1984-06-01

    Under certain conditions genuine coral calculi are an absolute offication for nephrotomy. In order to achieve complete hygienization of the cavity ischaemia times of more than 25-30 min are often necessary. Controlled surface cooling proved to be very good for improving ischaemia tolerance and reducing post-ischaemic loss of function in 21 necessary nephrotomies out of a total of 651 operations for concrements in the calyx system of the renal pelvis (= 3.2%; = 32.8% of all nephrotomies). A kidney thermometer with a temperature feeler developed by us allows fine control of the hypothermia induced by means of plastic bags filled with ice crystals. The technique of operation together with its advantages and disadvantages are described.

  15. Gastric Mucosal Petechial Hemorrhages (Wischnewsky Lesions), Hypothermia, and Diabetic Ketoacidosis.

    PubMed

    Clark, Kenneth Howard; Stoppacher, Robert

    2016-09-01

    For more than 100 years since their initial description, gastric mucosal petechial hemorrhages have been discovered at autopsy in cases where environmental hypothermia was determined to be the cause of death. Although these lesions are frequently seen in deaths caused by environmental hypothermia, they can also be seen in cases where hypothermia is not implicated; however, this has been seldom described. We present a series of autopsy cases where hypothermia has been conclusively ruled out as a cause of death, in which Wischnewsky lesions are found. In all of these cases, diabetic ketoacidosis (DKA) was determined to be the proximate cause of death, as confirmed through clinical history, laboratory analysis, and absence of other anatomic or toxicological findings. We provide a mechanism of Wischnewsky lesion formation and how that mechanism relates to both hypothermia and ketoacidosis. Our data show that gastric mucosal petechial hemorrhages are not specific for hypothermia-related deaths, and are likely indicative of a state in which hypothermia and DKA have a common underlying pathophysiology, most likely a coagulopathy. Our data also illustrate that in autopsy cases where Wischnewsky lesions are found, DKA should be seriously considered as the underlying cause of death, particularly in the absence of indications of environmental hypothermia.

  16. Hypothermia improves disease manifestations in SMA mice via SMN augmentation.

    PubMed

    Tsai, Li-Kai; Chen, Chien-Lin; Tsai, Yi-Chieh; Ting, Chen-Hung; Chien, Yin-Hsio; Lee, Ni-Chong; Hwu, Wuh-Liang

    2016-02-15

    Spinal muscular atrophy (SMA) is a progressive motor neuron disease caused by a deficiency of survival motor neuron (SMN) protein. In this study, we evaluated the efficacy of intermittent transient hypothermia in a mouse model of SMA. SMA mice were exposed to ice for 50 s to achieve transient hypothermia (below 25°C) daily beginning on postnatal day 1. Neonatal SMA mice (Smn(-/-)SMN2(+/-)) who received daily transient hypothermia exhibited reduced motor neuron degeneration and muscle atrophy and preserved the architecture of neuromuscular junction when compared with untreated controls at day 8 post-treatment. Daily hypothermia also prolonged the lifespan, increased body weight and improved motor coordination in SMA mice. Quantitative polymerase chain reaction and western blot analyses showed that transient hypothermia led to an increase in SMN transcript and protein levels in the spinal cord and brain. In in vitro studies using an SMN knockdown motor neuron-like cell-line, transient hypothermia increased intracellular SMN protein expression and length of neurites, confirming the direct effect of hypothermia on motor neurons. These data indicate that the efficacy of intermittent transient hypothermia in improving outcome in an SMA mouse model may be mediated, in part, via an upregulation of SMN levels in the motor neurons.

  17. Mechanisms of Hypothermia, Delayed Hyperthermia and Fever Following CNS Injury

    EPA Science Inventory

    Central nervous system (CNS) damage is often associated with robust body temperature changes, such as hypothermia and delayed hyperthermia. Hypothermia is one of the most common body temperature changes to CNS insults in rodents and is often associated with improved outcome. Alth...

  18. Asphyxia and Therapeutic Hypothermia Modulate Plasma Nitrite Concentrations and Carotid Vascular Resistance in Preterm Fetal Sheep

    PubMed Central

    Barrett, Robert D.; Bennet, Laura; Blood, Arlin B.; Wassink, Guido

    2014-01-01

    In this study, we tested the hypothesis that cerebral hypoperfusion after asphyxia and induced hypothermia is associated with reduced circulating nitrite levels as an index of nitric oxide synthase (NOS) activity. The preterm fetal sheep at 0.7 gestation (103-104 days, term = 147 days) received 25-minute umbilical cord occlusion, followed by mild whole-body cooling from 30 minutes to 72 hours after occlusion. Occlusion and induced hypothermia were independently associated with reduced carotid vascular conductance (CaVC) from 2 to 72 hours, and with transiently suppressed plasma nitrite levels at 6 hours. There was a significant within-subjects correlation (r 2 = 0.33, P = .002) between CaVC and plasma nitrite values in the first 24 hours after occlusion but not after sham occlusion. These findings suggest that in preterm fetal sheep, changes in NOS activity are an important mediator of changes in carotid vascular tone in the early recovery phase after asphyxia and may help mediate some of the vascular effects of induced hypothermia. PMID:24740991

  19. [Normothermia and hypothermia from an anaesthesiological viewpoint].

    PubMed

    Pannen, B H J

    2007-09-01

    For a long time the significance of perioperative accidental hypothermia was overlooked. The possible undesirable effects of a relatively small reduction in the body core temperature of 1.5-2.0 degrees C were generally unknown and the treatment options were limited. The unfavourable climatic conditions in the operation room favour heat loss and simultaneously, there is considerable disturbance of temperature regulation through general as well as spinal anaesthesia. In many studies it has now been shown that the resulting decrease in body temperature can have a negative effect on immune function, coagulation, the cardiovascular system and recovery behaviour. Heat loss in the perioperative phase should, therefore, be minimised by effective insulation. Nevertheless, a negative heat balance can often only be avoided by an additional heat treatment of the body surface which ideally should be initiated in the preoperative phase. If large volumes must be infused, an important additional measure is to prewarm these solutions. This is the only way in which the objective, to avoid a fall in body temperature to below 36 degrees C in the perioperative phase and the possible subsequent negative effects on the course of events, can be reached. The incidence of perioperative hypothermia is often underestimated so that in this phase a reduction in body core temperature of more than 2 degrees C will occur in more than 50% of patients if no special measures are undertaken. In addition, the undesirable effects of such a reduction in core temperature were barely known and even only a few years ago there were hardly any possibilities for reliable prevention or effective treatment. Therefore, in this article the causes of perioperative hypothermia will initially be described. In the second section the possible negative consequences of a reduction in body core temperature will be presented and in the last section the resulting consequences for the practice will be discussed.

  20. [Pathophysiology and management of perioperative hypothermia].

    PubMed

    Witkowski, Wojciech; Maj, Jakub

    2006-06-01

    The paper is a review of pathophysiology and management of perioperative hypothermia. The advanced methods of rewarming, such as passive and active: external and core used in clinic allow for efficient management ant prophylactics of hypothermia. Thermotherapy with use of infrared ceiling heaters CTS and mobile MTC as well as Infutherm system applying by authors are desirable and even indispensable in contemporary equipment of surgery clinics, cardiovascular surgery clinics and burn centers. The ideal rewarming method should be safe and enable fast, reliable and predictable warming or rewarming. The clinical parameter to determine the efficacy of rewarming is the change of core temperature. There is no doubt that active warming with forced-air warmers (Warm Touch 5700 and Bair Hugger 500) or radiative heaters (IR-A:Hydrosun 500, IR-C radiation: CTC X, MTC) is more effective than use of standard, passive insulation hospital blankets or convectional heaters. Actually the forced-air warmers are counted to be more useful in cardiovascular surgery hypothermia management, because of fast rate core temperature rise and faster rise in mean skin temperature compared to the control group. CTC X and MTC Aragona radiative heaters are useful in burn management being the most effective when the distance of heater from the patient body is less than 80 cm. The observation of 60 consecutive extensive burns leads to conclusion that long-lasting dressings in burn patients when the whole body is not covered and protected, can be performed safely only in conditions excluding heat losses and core temperature drop. While the cold intravenous fluids may significantly contribute to the temperature drop depending on the volume infused, the use of fluids warming systems as well as external heat application is absolutely indicated to improve the heat balance of the patient body.

  1. Optimal Protective Hypothermia in Arrested Mammalian Hearts

    PubMed Central

    Villet, Outi M.; Ge, Ming; Sekhar, Laigam N.; Corson, Marshall A.; Tylee, Tracy S.; Fan, Lu-Ping; Yao, Lin; Zhu, Chun; Olson, Aaron K.; Buroker, Norman E.; Xu, Cheng-Su; Anderson, David L.; Soh, Yong-Kian; Wang, Elise; Chen, Shi-Han; Portman, Michael A.

    2015-01-01

    Many therapeutic hypothermia recommendations have been reported, but the information supporting them is sparse, and reveals a need for the data of target therapeutic hypothermia (TTH) from well-controlled experiments. The core temperature ≤35°C is considered as hypothermia, and 29°C is a cooling injury threshold in pig heart in vivo. Thus, an optimal protective hypothermia (OPH) should be in the range 29–35°C. This study was conducted with a pig cardiopulmonary bypass preparation to decrease the core temperature to 29–35°C range at 20 minutes before and 60 minutes during heart arrest. The left ventricular (LV) developed pressure, maximum of the first derivative of LV (dP/dtmax), cardiac power, heart rate, cardiac output, and myocardial velocity (Vmax) were recorded continuously via an LV pressure catheter and an aortic flow probe. At 20 minutes of off-pump during reperfusion after 60 minutes arrest, 17 hypothermic hearts showed that the recovery of Vmax and dP/dtmax established sigmoid curves that consisted of two plateaus: a good recovery plateau at 29–30.5°C, the function recovered to baseline level (BL) (Vmax=118.4%±3.9% of BL, LV dP/dtmax=120.7%±3.1% of BL, n=6); another poor recovery plateau at 34–35°C (Vmax=60.2%±2.8% of BL, LV dP/dtmax=28.0%±5.9% of BL, p<0.05, n=6; ), which are similar to the four normothermia arrest (37°C) hearts (Vmax=55.9%±4.8% of BL, LV dP/dtmax=24.5%±2.1% of BL, n=4). The 32–32.5°C arrest hearts showed moderate recovery (n=5). A point of inflection (around 30.5–31°C) existed at the edge of a good recovery plateau followed by a steep slope. The point presented an OPH that should be the TTH. The results are concordant with data in the mammalian hearts, suggesting that the TTH should be initiated to cool core temperature at 31°C. PMID:25514569

  2. Hypothermia attenuates apoptosis and protects contact between myelin basic protein-expressing oligodendroglial-lineage cells and neurons against hypoxia-ischemia.

    PubMed

    Ichinose, Mari; Kamei, Yoshimasa; Iriyama, Takayuki; Imada, Shinya; Seyama, Takahiro; Toshimitsu, Masatake; Asou, Hiroaki; Yamamoto, Masahiro; Fujii, Tomoyuki

    2014-10-01

    Periventricular leukomalacia (PVL) is a major form of brain injury among preterm infants, which is characterized by extensive loss and dysfunction of premyelinating oligodendrocytes (pre-OLs) induced by hypoxia-ischemia (HI). Therapeutic hypothermia, which is a standard treatment for term infants with HI encephalopathy, is not indicated for preterm infants because its safety and effect have not been established. Here we investigate the effectiveness and mechanism of hypothermia for the inhibition of pre-OLs damage in PVL. For in vivo studies, 6-day-old rats underwent left carotid artery ligation, followed by exposure to 6% oxygen for 1 hr under hypothermic or normothermic conditions. The loss of myelin basic protein (MBP) was inhibited by hypothermia. For in vitro studies, primary pre-OLs cultures were subjected to oxygen-glucose deprivation (OGD) under normothermic or hypothermic conditions, and dorsal root ganglion neurons were subsequently added. Hypothermia inhibited apoptosis of pre-OLs, and, despite specific downregulation of 21.5- and 17-kDa MBP mRNA expression during hypothermia, recovery of the expression after OGD was superior compared with normothermia. OGD caused disarrangement of MBP distribution, decreased the levels of phosphorylated 21.5-kDa MBP, and disturbed the capacity to contact with neurons, all of which were restored by hypothermia. Pharmacological inhibition of ERK1/2 phosphorylation with U0126 during and after OGD significantly reduced the protective effects of hypothermia on apoptosis and myelination, respectively. These data suggest that phosphorylated exon 2-containing (21.5- and possibly 17-kDa) MBP isoforms may play critical roles in myelination and that hypothermia attenuates apoptosis and preserves the contact between OLs and neurons via ERK1/2 phosphorylation.

  3. Mild hypothermia attenuates changes in respiratory system mechanics and modifies cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation.

    PubMed

    Dostál, P; Senkeřík, M; Pařízková, R; Bareš, D; Zivný, P; Zivná, H; Cerný, V

    2010-01-01

    Hypothermia was shown to attenuate ventilator-induced lung injury due to large tidal volumes. It is unclear if the protective effect of hypothermia is maintained under less injurious mechanical ventilation in animals without previous lung injury. Tracheostomized rats were randomly allocated to non-ventilated group (group C) or ventilated groups of normothermia (group N) and mild hypothermia (group H). After two hours of mechanical ventilation with inspiratory fraction of oxygen 1.0, respiratory rate 60 min(-1), tidal volume 10 ml x kg(-1), positive end-expiratory pressure (PEEP) 2 cm H2O or immediately after tracheostomy in non-ventilated animals inspiratory pressures were recorded, rats were sacrificed, pressure-volume (PV) curve of respiratory system constructed, bronchoalveolar lavage (BAL) fluid and aortic blood samples obtained. Group N animals exhibited a higher rise in peak inspiratory pressures in comparison to group H animals. Shift of the PV curve to right, higher total protein and interleukin-6 levels in BAL fluid were observed in normothermia animals in comparison with hypothermia animals and non-ventilated controls. Tumor necrosis factor-alpha was lower in the hypothermia group in comparison with normothermia and non-ventilated groups. Mild hypothermia attenuated changes in respiratory system mechanics and modified cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation in animals without previous lung injury.

  4. In an era of rapid STEMI reperfusion with Primary Percutaneous Coronary Intervention is there a role for adjunct therapeutic hypothermia? A structured literature review.

    PubMed

    Saunderson, Christopher E D; Chowdhary, Amrit; Brogan, Richard A; Batin, Phillip D; Gale, Christopher P

    2016-11-15

    Mild hypothermia has been shown to improve neurological outcome and reduce mortality following out of hospital cardiac arrest. In animal models the application of hypothermia with induced coronary occlusion has demonstrated a reduction in infarct size. Consequently, hypothermia has been proposed as a treatment, in addition to Primary Percutaneous Coronary Intervention (PPCI) for ST segment elevation myocardial infarction (STEMI). However, there is incomplete understanding of the mechanism and magnitude of the protective effect of hypothermia on the myocardium, and limited outcome data. We undertook a structured literature review of therapeutic hypothermia as adjuvant to PPCI for acute STEMI. We examined the feasibility, safety, impact on infarct size and the resultant effect on major adverse cardiac events and mortality. There were 13 studies between 1946 and 2016. With the exception of one study, therapeutic hypothermia for STEMI was reported to be feasible and safe, and its only demonstrable benefit was a modest reduction in post-infarct heart failure events. Evidence to date, however, is from small clinical trials and in an era of low early mortality following PPCI for STEMI, demonstrating a mortality benefit will be challenging. Post-myocardial infarction left ventricular dysfunction is a more frequent, alternative clinical outcome and therefore any intervention that mitigates this warrants further investigation.

  5. Myocardial correlates of helium-cold induction and maintenance of hypothermia.

    NASA Technical Reports Server (NTRS)

    Anderson, G. L.; Prewitt, R., Jr.; Musacchia, X. J.

    1971-01-01

    Hypothermia was induced in the golden hamster Mesocricetus auratus, using the helium-cold method. The first group of hamsters was sacrificed immediately after induction to rectal temperature 7 C, a second group was sacrificed after being maintained at a body temperature of 7 C for 18-24 hr, and a third group consisted of unexposed controls. The hearts were excised and the ventricles analyzed for hypoxic damage, glycogen, and catecholamines. In the short-term hypothermic animals, resting tension was increased while peak isometric tension, generated tension after 10 min of anoxic exposure, glycogen, and catecholamines were all reduced. All of the functional parameters recovered in the long-term hypothermic group, while glycogen and catecholamines showed a trend toward recovery. It is concluded that myocardial hypoxia develops during induction into hypothermia when using the helium-cold method. This effect is reversible and hypoxic damage does not increase as the hypothermic exposure is prolonged.

  6. Optimization of induction of mild therapeutic hypothermia with cold saline infusion: A laboratory experiment.

    PubMed

    Fluher, Jure; Markota, Andrej; Stožer, Andraž; Sinkovič, Andreja

    2015-11-12

    Cold fluid infusions can be used to induce mild therapeutic hypothermia after cardiac arrest. Fluid temperature higher than 4°C can increase the volume of fluid needed, prolong the induction phase of hypothermia and thus contribute to complications. We performed a laboratory experiment with two objectives. The first objective was to analyze the effect of wrapping fluid bags in ice packs on the increase of fluid temperature with time in bags exposed to ambient conditions. The second objective was to quantify the effect of insulating venous tubing and adjusting flow rate on fluid temperature increase from bag to the level of an intravenous cannula during a simulated infusion. The temperature of fluid in bags wrapped in ice packs was significantly lower compared to controls at all time points during the 120 minutes observation. The temperature increase from the bag to the level of intravenous cannula was significantly lower for insulated tubing at all infusion rates (median temperature differences between bag and intravenous cannula were: 8.9, 4.8, 4.0, and 3.1°C, for non-insulated and 5.9, 3.05, 1.1, and 0.3°C, for insulated tubing, at infusion rates 10, 30, 60, and 100 mL/minute, respectively). The results from this study could potentially be used to decrease the volume of fluid infused when inducing mild hypothermia with an infusion of cold fluids.

  7. The effect of hypothermia on the expression of TIMP-3 after traumatic brain injury in rats.

    PubMed

    Jia, Feng; Mao, Qing; Liang, Yu-Min; Jiang, Ji-Yao

    2014-02-15

    Here we investigate the effect of hypothermia on the expression of apoptosis-regulating protein TIMP-3 after fluid percussion traumatic brain injury (TBI) in rats. We began with 210 adult male Sprague-Dawley rats and randomly assigned them to three groups: TBI with hypothermia treatment (32°C), TBI with normothermia (37°C), and sham-injured controls. TBI was induced by a fluid percussion TBI device. Mild hypothermia (32°C) was achieved by partial immersion in a water bath (0°C) under general anesthesia for 4 h. The rats were killed at 4, 6, 12, 24, 48, and 72 h and 1 week after TBI. The mRNA and protein level of TIMP-3 in both the injured and uninjured hemispheres of the brains from each group were measured using RT-PCR and Western blotting. In the normothermic group, TIMP-3 levels in both the injured and uninjured hemispheres were significantly increased after TBI compared with those of sham-injured animals (p < 0.01). In contrast, post-traumatic hypothermia significantly attenuated this increase. According to the RT-PCR and Western blot analyses, the maximum mRNA levels of TIMP-3 were reduced to 60.60 ± 2.30%, 55.83 ± 1.80%, 66.03 ± 2.10%, and 64.51 ± 1.50%, respectively, of the corresponding values in the normothermic group in the injured and uninjured hemispheres (cortex and hippocampus) of the hypothermia group (p < 0.01), while the respective maximum protein levels of TIMP-3 were reduced to 57.50 ± 1.50, 52.67 ± 2.20, 60.31 ± 2.50 and 54.76 ± 1.40 (p < 0.01). Our data suggest that moderate fluid percussion brain injury significantly upregulates TIMP-3 expression, and that this increase may be suppressed by hypothermia treatment.

  8. Intraoperative Hypothermia During Surgical Fixation of Hip Fractures.

    PubMed

    Frisch, Nicholas B; Pepper, Andrew M; Jildeh, Toufic R; Shaw, Jonathan; Guthrie, Trent; Silverton, Craig

    2016-11-01

    Hip fractures are common orthopedic injuries and are associated with significant morbidity/mortality. Intraoperative normothermia is recommended by national guidelines to minimize additional morbidity/mortality, but limited evidence exists regarding hypothermia's effect on orthopedic patients. The purpose of this study was to determine the incidence of intraoperative hypothermia in patients with operatively treated hip fractures and evaluate its effect on complications and outcomes. Retrospective chart review was performed on clinical records from 1541 consecutive patients who sustained a hip fracture and underwent operative fixation at the authors' institution between January 2005 and October 2013. A total of 1525 patients were included for analysis, excluding those with injuries requiring additional surgical intervention. Patient demographic data, surgery-specific data, postoperative complications, length of stay, and 30-day readmission were recorded. Patients with a mean intraoperative temperature less than 36°C were identified as hypothermic. Statistical analysis with univariate and multivariate logistic regression modeling evaluated associations with hypothermia and effect on complications/outcomes. The incidence of intraoperative hypothermia in operatively treated hip fractures was 17.0%. Hypothermia was associated with an increase in the rate of deep surgical-site infection (odds ratio, 3.30; 95% confidence interval, 1.19-9.14; P=.022). Lower body mass index and increasing age demonstrated increased association with hypothermia (P=.004 and P=.005, respectively). To the authors' knowledge, this is the first and largest study analyzing the effect of intraoperative hypothermia in orthopedic patients. In patients with hip fractures, the study's findings confirm evidence found in other surgical specialties that hypothermia may be associated with an increased risk of deep surgical-site infection and that lower body mass index and increasing age are risk factors

  9. Intraoperative Hypothermia in Total Hip and Knee Arthroplasty.

    PubMed

    Frisch, Nicholas B; Pepper, Andrew M; Rooney, Edward; Silverton, Craig

    2016-10-25

    Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common and successful orthopedic procedures, and as their frequency continues to increase substantially, the focus on limiting perioperative complications heightens. Intraoperative normothermia is recommended to minimize additional complications, but limited evidence exists regarding the effect of hypothermia on orthopedic patients. The purpose of this retrospective study was to determine the incidence of perioperative hypothermia in the setting of TKA and THA, and to evaluate its impact on complications and outcomes. The clinical records of 2580 consecutive patients who underwent TKA or THA at a single institution between January 1, 2011, and December 31, 2013 were reviewed. After excluding patients with complex or revision procedures, a total of 2397 patients comprised the study population. Patient demographic data, surgery-specific data, postoperative complications, length of hospital stay, and 30-day readmission were recorded. Patients with a mean intraoperative temperature less than 36°C were identified as hypothermic. Statistical analysis evaluated associations with hypothermia and the effect on complications and outcomes. The incidence of mean intraoperative hypothermia was 37%, 43.9%, and 32.6% for arthroplasty, THA, and TKA, respectively. General anesthesia was significantly associated with hypothermia (P<.001). Women and THA patients were at higher risk for hypothermia. In the arthroplasty and THA cohorts, longer operating room time and re-warmer use were associated with hypothermia (P=.010). Overall, hypothermia was associated with increased estimated blood loss, but no increase in associated transfusion was demonstrated (P=.006). Hypothermia was not associated with postoperative complications. [Orthopedics. 201x; xx(x):xx-xx.].

  10. Beneficial effects of nitric oxide on outcomes after cardiac arrest and cardiopulmonary resuscitation in hypothermia-treated mice

    PubMed Central

    Kida, Kotaro; Shirozu, Kazuhiro; Yu, Binglan; Mandeville, Joseph B.; Bloch, Kenneth D.; Ichinose, Fumito

    2015-01-01

    Background Therapeutic hypothermia (TH) improves neurological outcomes after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). Although nitric oxide prevents organ injury induced by ischemia and reperfusion, role of nitric oxide during TH after CPR remains unclear. Here, we examined the impact of endogenous nitric oxide synthesis on the beneficial effects of hypothermia after CA/CPR. We also examined whether or not inhaled nitric oxide during hypothermia further improves outcomes after CA/CPR in mice treated with TH. Methods Wild-type (WT) mice and mice deficient for nitric oxide synthase 3 (NOS3−/−) were subjected to CA at 37°C and then resuscitated with chest compression. Body temperature was maintained at 37°C (normothermia) or reduced to 33°C (TH) for 24 hours after resuscitation. Mice breathed air or air mixed with nitric oxide at 10, 20, 40, 60, or 80 ppm during hypothermia. To evaluate brain injury and cerebral blood flow, magnetic resonance imaging was performed in WT mice after CA/CPR. Results Hypothermia up-regulated the NOS3-dependent signaling in the brain (n=6–7). Deficiency of NOS3 abolished the beneficial effects of hypothermia after CA/CPR (n=5–6). Breathing nitric oxide at 40 ppm improved survival rate in hypothermia-treated NOS3−/− mice (n=6) after CA/CPR compared to NOS3−/− mice that were treated with hypothermia alone (n=6, P<0.05). Breathing nitric oxide at 40 (n=9) or 60 (n=9) ppm markedly improved survival rates in TH-treated WT mice (n=51) (both P<0.05 vs TH-treated WT mice). Inhaled nitric oxide during TH (n=7) prevented brain injury compared to TH alone (n=7) without affecting cerebral blood flow after CA/CPR (n=6). Conclusions NOS3 is required for the beneficial effects of TH. Inhaled nitric oxide during TH remains beneficial and further improves outcomes after CA/CPR. Nitric oxide breathing exerts protective effects after CA/CPR even when TH is ineffective due to impaired endogenous nitric oxide production

  11. Mechanisms responsible for decreased glomerular filtration in hibernation and hypothermia

    NASA Technical Reports Server (NTRS)

    Tempel, G. E.; Musacchia, X. J.; Jones, S. B.

    1977-01-01

    Measurements of blood pressure, heart rate, red blood cell and plasma volumes, and relative distribution of cardiac output were made on hibernating and hypothermic adult male and female golden hamsters weighing 120-140 g to study the mechanisms underlying the elimination or marked depression of renal function in hibernation and hypothermia. The results suggest that the elimination or marked depression in renal function reported in hibernation and hypothermia may partly be explained by alterations in cardiovascular system function. Renal perfusion pressure which decreases nearly 60% in both hibernation and hypothermia and a decrease in plasma volume of roughly 35% in the hypothermic animal might both be expected to markedly alter glomerular function.

  12. Short Duration Combined Mild Hypothermia Improves Resuscitation Outcomes in a Porcine Model of Prolonged Cardiac Arrest

    PubMed Central

    Yu, Tao; Yang, Zhengfei; Li, Heng; Ding, Youde; Huang, Zitong; Li, Yongqin

    2015-01-01

    Objective. In this study, our aim was to investigate the effects of combined hypothermia with short duration maintenance on the resuscitation outcomes in a porcine model of ventricular fibrillation (VF). Methods. Fourteen porcine models were electrically induced with VF and untreated for 11 mins. All animals were successfully resuscitated manually and then randomized into two groups: combined mild hypothermia (CH group) and normothermia group (NT group). A combined hypothermia of ice cold saline infusion and surface cooling was implemented in the animals of the CH group and maintained for 4 hours. The survival outcomes and neurological function were evaluated every 24 hours until a maximum of 96 hours. Neuron apoptosis in hippocampus was analyzed. Results. There were no significant differences in baseline physiologies and primary resuscitation outcomes between both groups. Obvious improvements of cardiac output were observed in the CH group at 120, 180, and 240 mins following resuscitation. The animals demonstrated better survival at 96 hours in the CH group when compared to the NT group. In comparison with the NT group, favorable neurological functions were observed in the CH group. Conclusion. Short duration combined cooling initiated after resuscitation improves survival and neurological outcomes in a porcine model of prolonged VF. PMID:26558261

  13. Severe Local Hypothermia from Laparoscopic Gas Evaporative Jet Cooling: A Mechanism To Explain Clinical Observations

    PubMed Central

    Gray, Robert I.; Henderson, A. Courtney; Cochran, Steve A.; Roth, Elizabeth A.

    1999-01-01

    Background and Objectives: Explanations for laparoscopic-induced hypothermia fail to explain clinical observations. It is possible that water evaporation occurs from the jet stream of gas inflation resulting in tissue surface super-cooling leading to tissue damage and drying. Methods: Theoretical calculations based on thermal conductivity, mass transfer effects and heat flux considerations correlated closely with synthetic and tissue experiments. Thermocouple measurements at a rate of 15 data points per second were performed. Results: Cooling rates of 10 to 25 degrees centigrade per second for high flow rates were found based on gas flow rate and effective size of gas delivery site. These rapid temperature drops extended beyond a 2 cm2 diameter. Conclusions: Evaporative cooling accounts for significant hypothermia. The cooling is dependent on the lack of water vapor in the gases currently used during laparoscopy. Cooling rates are independent of height from tissue and geometry of delivery port. Heating and hydrating the gas to a physiologic condition eliminates hypothermia and tissue dessication. PMID:10527326

  14. Reducing the risk of unplanned perioperative hypothermia.

    PubMed

    Lynch, Susan; Dixon, Jacqueline; Leary, Donna

    2010-11-01

    Maintaining normothermia is important for patient safety, positive surgical outcomes, and increased patient satisfaction. Causes of unplanned hypothermia in the OR include cold room temperatures, the effects of anesthesia, cold IV and irrigation fluids, skin and wound exposure, and patient risk factors. Nurses at Riddle Memorial Hospital in Media, Pennsylvania, performed a quality improvement project to evaluate the effectiveness of using warm blankets, warm irrigation fluids, or forced-air warming on perioperative patients to maintain their core temperature during the perioperative experience. Results of the project showed that 75% of patients who received forced-air warming perioperatively had temperatures that reached or were maintained at 36° C (96.8° F) or higher within 15 minutes after leaving the OR.

  15. Accidental Hypothermia among the Elderly: An Educational Prevention Program.

    ERIC Educational Resources Information Center

    Goldstein, Marc B.

    1982-01-01

    Discusses the problem of hypothermia and specific factors that put older adults at risk. Describes the development, implementation, and evaluation of an educationally oriented prevention program. Data suggested the information presented through community education was effective. (Author/JAC)

  16. Mild hypothermia alters midazolam pharmacokinetics in normal healthy volunteers.

    PubMed

    Hostler, David; Zhou, Jiangquan; Tortorici, Michael A; Bies, Robert R; Rittenberger, Jon C; Empey, Philip E; Kochanek, Patrick M; Callaway, Clifton W; Poloyac, Samuel M

    2010-05-01

    The clinical use of therapeutic hypothermia has been rapidly expanding due to evidence of neuroprotection. However, the effect of hypothermia on specific pathways of drug elimination in humans is relatively unknown. To gain insight into the potential effects of hypothermia on drug metabolism and disposition, we evaluated the pharmacokinetics of midazolam as a probe for CYP3A4/5 activity during mild hypothermia in human volunteers. A second objective of this work was to determine whether benzodiazepines and magnesium administered intravenously would facilitate the induction of hypothermia. Subjects were enrolled in a randomized crossover study, which included two mild hypothermia groups (4 degrees C saline infusions and 4 degrees C saline + magnesium) and two normothermia groups (37 degrees C saline infusions and 37 degrees C saline + magnesium). The lowest temperatures achieved in the 4 degrees C saline + magnesium and 4 degrees C saline infusions were 35.4 +/- 0.4 and 35.8 +/- 0.3 degrees C, respectively. A significant decrease in the formation clearance of the major metabolite 1'-hydroxymidazolam was observed during the 4 degrees C saline + magnesium compared with that in the 37 degrees C saline group (p < 0.05). Population pharmacokinetic modeling identified a significant relationship between temperature and clearance and intercompartmental clearance for midazolam. This model predicted that midazolam clearance decreases 11.1% for each degree Celsius reduction in core temperature from 36.5 degrees C. Midazolam with magnesium facilitated the induction of hypothermia, but shivering was minimally suppressed. These data provided proof of concept that even mild and short-duration changes in body temperature significantly affect midazolam metabolism. Future studies in patients who receive lower levels and a longer duration of hypothermia are warranted.

  17. Hypometabolism and hypothermia in the rat model of endotoxic shock: independence of circulatory hypoxia.

    PubMed

    Corrigan, Joshua J; Fonseca, Monique T; Flatow, Elizabeth A; Lewis, Kevin; Steiner, Alexandre A

    2014-09-01

    We tested the hypothesis that development of hypothermia instead of fever in endotoxic shock is consequential to hypoxia. Endotoxic shock was induced by bacterial lipopolysaccharide (LPS, 500 μg kg(-1) i.v.) in rats at an ambient temperature of 22 °C. A β3-adrenergic agonist known to activate metabolic heat production, CL316,243, was employed to evaluate whether thermogenic capacity could be impaired by the fall in oxygen delivery (ḊO2) during endotoxic shock. This possibility was rejected as CL316,243 (0.15 mg kg(-1) i.v.) evoked similar rises in oxygen consumption (V̇O2) in the presence and absence of endotoxic shock. Next, to investigate whether a less severe form of circulatory hypoxia could be triggering hypothermia, the circulating volume of LPS-injected rats was expanded using 6% hetastarch with the intention of improving tissue perfusion and alleviating hypoxia. This intervention attenuated not only the fall in arterial pressure induced by LPS, but also the associated falls in V̇O2 and body temperature. These effects, however, occurred independently of hypoxia, as they were not accompanied by any detectable changes in NAD(+)/NADH ratios. Further experimentation revealed that even the earliest drops in cardiac output and ḊO2 during endotoxic shock did not precede the reduction in V̇O2 that brings about hypothermia. In fact, ḊO2 and V̇O2 fell in such a synchrony that the ḊO2/V̇O2 ratio remained unaffected. Only when hypothermia was prevented by exposure to a warm environment (30 °C) did an imbalance in the ḊO2/V̇O2 ratio become evident, and such an imbalance was associated with reductions in the renal and hypothalamic NAD(+)/NADH ratios. In conclusion, hypometabolism and hypothermia in endotoxic shock are not consequential to hypoxia but serve as a pre-emptive strategy to avoid hypoxia in this model.

  18. Morphological study of the relation between accidental hypothermia and acute pancreatitis.

    PubMed Central

    Foulis, A K

    1982-01-01

    There is a recognised but poorly understood association between hypothermia and acute pancreatitis. A histological study of the pancreas was made in eight patients with accidental hypothermia who had evidence of pancreatitis at necropsy. From an analysis of the patterns of parenchymal necrosis in the pancreas it was thought that there were at least three possible mechanisms for the relation between hypothermia and pancreatitis. Firstly, that ischaemic pancreatitis may result from the "microcirculatory shock" of hypothermia. Secondly, that both hypothermia and pancreatitis may be secondary to alcohol abuse: and finally, that severe pancreatitis may be the primary disease and that hypothermia results from the patients' social circumstances. Images PMID:7142433

  19. Mild hypothermia, but not propofol, is neuroprotective in organotypic hippocampal cultures.

    PubMed

    Feiner, John R; Bickler, Philip E; Estrada, Sergio; Donohoe, Paul H; Fahlman, Christian S; Schuyler, Jennifer A

    2005-01-01

    The neuroprotective potency of anesthetics such as propofol compared to mild hypothermia remains undefined. Therefore, we determined whether propofol at two clinically relevant concentrations is as effective as mild hypothermia in preventing delayed neuron death in hippocampal slice cultures (HSC). Survival of neurons was assessed 2 and 3 days after 1 h oxygen and glucose deprivation (OGD) either at 37 degrees C (with or without 10 or 100 microM propofol) or at an average temperature of 35 degrees C during OGD (mild hypothermia). Cell death in CA1, CA3, and dentate neurons in each slice was measured with propidium iodide fluorescence. Mild hypothermia eliminated death in CA1, CA3, and dentate neurons but propofol protected dentate neurons only at a concentration of 10 microM; the more ischemia vulnerable CA1 and CA3 neurons were not protected by either 10 microM or 100 microM propofol. In slice cultures, the toxicity of 100 muM N-methyl-D-aspartate (NMDA), 500 microM glutamate, and 20 microM alpha-amino-5-methyl-4-isoxazole propionic acid (AMPA) was not reduced by 100 microM propofol. Because propofol neuroprotection may involve gamma-aminobutyric acid (GABA)-mediated indirect inhibition of glutamate receptors (GluRs), the effects of propofol on GluR activity (calcium influx induced by GluR agonists) were studied in CA1 neurons in HSC, in isolated CA1 neurons, and in cortical brain slices. Propofol (100 and 200 microM, approximate burst suppression concentrations) decreased glutamate-mediated [Ca2+]i increases (Delta[Ca2+]i) responses by 25%-35% in isolated CA1 neurons and reduced glutamate and NMDA Delta[Ca2+]i in acute and cultured hippocampal slices by 35%-50%. In both CA1 neurons and cortical slices, blocking GABAA receptors with picrotoxin reduced the inhibition of GluRs substantially. We conclude that mild hypothermia, but not propofol, protects CA1 and CA3 neurons in hippocampal slice cultures subjected to oxygen and glucose deprivation. Propofol was not

  20. Effect of hypothermia on baroreflex control of heart rate and renal sympathetic nerve activity in anaesthetized rats

    PubMed Central

    Sabharwal, R; Coote, J H; Johns, E J; Egginton, S

    2004-01-01

    The present study investigated the effect of acute hypothermia on baroreflex control of heart rate (HR) and renal sympathetic nerve activity (RSNA) by generating baroreflex logistic function curves, using bolus doses of phenylephrine and sodium nitroprusside, in anaesthetized male Wistar rats at a core temperature (Tb) of 37°C, during acute severe hypothermia at Tb= 25°C and on rewarming to 37°C. Comparisons were made between rats without (euthermic, n = 6) and with (acclimated, n = 7) prior exposure to lower ambient temperatures and shorter photoperiod, simulating adaptation to winter conditions. In both groups of rats, acute hypothermia to Tb= 25°C shifted the baroreflex-RSNA curve slightly leftwards and downwards with decreases in the setpoint pressure and maximal gain, whereas it markedly impaired the baroreflex-HR curve characterized by decreases in response range by ∼90% (P < 0.001), minimum response by ∼10% (P < 0.05) and maximum gain by ∼95% (P < 0.001), from that at Tb= 37°C. All parameters were restored to precooling levels on rewarming. Electrical stimulation of cardiac vagal efferents induced a voltage-related bradycardia, the magnitude of which was partially reduced during acute hypothermia, and there was a significant prolongation of the electrocardiogram intervals indicating a delay in cardiac conduction. Mild suppression of baroreflex control of RSNA could contribute to hypothermic hypotension and may primarily reflect an effect of Tb on central drive. The marked attenuation of the baroreflex control of HR during hypothermia was likely to be due to an impairment of both the central and peripheral components of the reflex arc. Baroreflex control of RSNA and HR was similar between both groups of rats, which implied that the control was non-adaptive on chronic cold exposure. PMID:14978202

  1. Hypothermia: its possible role in cardiac surgery.

    PubMed

    Sealy, W C

    1989-05-01

    The current safety of operations on the heart requiring cardiopulmonary bypass occurred because of a series of step-by-step laboratory and clinical investigations that were compromises between the time needed for heart repair and the brain's requirement for oxygen. The first step, so clearly shown in a paper by Bigelow and associates in 1950, was the reduction of the brain's need for oxygen by surface cooling to 28 degrees to 32 degrees C, limited to this level by cardiac and pulmonary failure at levels lower than this. The six to eight minutes of circulatory arrest permitted time for repair of simple defects. This method was rapidly adopted by many surgeons. As low-flow pump oxygenators became available, blood cooling to 10 degrees to 20 degrees C was introduced. This increased the periods of circulatory arrest to 30 to 60 minutes, and also made still longer periods of bypass with the pump oxygenator possible. Hypothermia to reduce oxygen and metabolic requirements is still an important adjunct to bypass, even with the currently used efficient pump oxygenators. It remains the most important component of myocardial preservation, and has made possible the delay needed for transportation between the harvesting and the transplantation of organs.

  2. Free fatty acids as markers of death from hypothermia.

    PubMed

    Bańka, Krzysztof; Teresiński, Grzegorz; Buszewicz, Grzegorz

    2014-01-01

    The possibilities of using morphological markers of fatal hypothermia are limited; therefore, other diagnostic criteria of deaths from hypothermia are being researched. The initiation of protective mechanisms against adverse effects of low temperatures results in activation of hormonal systems and development of characteristic biochemical changes that can be impaired by alcohol intoxication. The aim of the study was to assess the usefulness of determinations of the profile of free fatty acid concentrations as potential markers of hypothermia-related deaths, particularly in intoxicated victims. The study group consisted of blood samples collected during autopsies of 23 victims of hypothermia. The control group included blood samples collected from 34 victims of sudden, violent deaths at the scene of an incident (hangings and traffic accidents) and 10 victims who died because of post-traumatic subdural hematomas with prolonged agony. The study and control groups were divided into three subgroups according to blood alcohol concentrations: 0.0-0.99; 1.0-2.99 and ≥3.0‰. Statistical analysis in the individual subgroups demonstrated significant increases in concentrations of palmitic, stearic and oleic acids (P<0.05), independent of blood ethanol concentration. Palmitic, stearic and oleic acids can be considered the potential markers of fatal hypothermia, including the cases of intoxicated individuals.

  3. [Prevention of perioperative hypothermia : Implementation of the S3 guideline].

    PubMed

    Horn, E-P; Klar, E; Höcker, J; Bräuer, A; Bein, B; Wulf, H; Torossian, A

    2017-01-09

    To improve perioperative quality and patient safety, the German S3 guideline should be consistently implemented to avoid perioperative hypothermia. Perioperative normothermia is a quality indicator and should be achieved by anesthesiologists and surgeons. To detect hypothermia early during the perioperative process, measuring body temperature should be started 1-2 h preoperatively. Patients should be actively warmed for 20-30 min before starting anesthesia. Prewarming is most effective and should be included in the preoperative process. Patients should be informed about the risks of perioperative hypothermia and members of the perioperative team should be educated. A standard operating procedure (SOP) to avoid hypothermia should be introduced in every operative unit. The incidence of postoperative hypothermia should be evaluated in operative patients every 3-6 months. The goals should be to measure body temperature in >80% of patients undergoing surgery and for >70% to exhibit a core temperature >36 °C at the end of surgery.

  4. Hypothermia Presenting in Wernicke Encephalopathy: A Case Report.

    PubMed

    Hong, Seok Hyun; Oh, Ju Sun; Lee, Chang Hyun; Oh, Jae Ho

    2017-02-01

    Wernicke encephalopathy (WE) is a neurologic disorder characterized by clinical symptoms, such as nystagmus, ataxia, and mental confusion. Hypothermia in patients with WE is a rare complication, and its pathogenic mechanism and therapy are yet to be ascertained. Herein, we presented a case of a 61-year-old man who was diagnosed with WE 3 months earlier. We investigated the cause of hypothermia (35.0℃) that occurred after an enema (bowel emptying). Brain magnetic resonance imaging revealed mammillary body and hypothalamus atrophy. In the autonomic function test, the sympathetic skin response (SSR) test did not evoke SSR latencies on both hands. In addition, abnormal orthostatic hypotension was observed. Laxative and stool softener medication were administered, and his diet was modified, which led to an improvement in constipation after 2 weeks. Moreover, there was no recurrence of hypothermic episode. This is the first reported case of late-onset hypothermia secondary to WE.

  5. Hypothermia and hypokalemia in a patient with diabetic ketoacidosis.

    PubMed

    Saito, Osamu; Saito, Takako; Sugase, Taro; Kusano, Eiji; Nagata, Daisuke

    2015-01-01

    We present the case of a 36-year-old man with type-1 diabetes who was hospitalized with diabetic ketoacidosis (DKA). On admission, he had hypothermia, hypokalemia and combined metabolic and respiratory alkalosis, in addition to hyperglycemia. Hypothermia, hypokalemia and metabolic alkalosis, with a concurrent respiratory alkalosis, are not commonly seen in DKA. After admission, intravenous infusion of 0.45% saline was administered, which resulted in the development of pure metabolic acidosis. After starting insulin infusion, hypokalemia and hypophosphatemia became evident and finally resulted in massive rhabdomyolysis. Hyperkalemia accompanying oliguric acute kidney injury (AKI) warranted initiation of hemodialysis (HD) on Day-five. On the 45th hospital day, his urine output started to increase and a total of 22 HD sessions were required. We believe that in this case severe dehydration, hypothermia and hypokalemia might have contributed to the initial symptoms of DKA as well as the prolongation of AKI.

  6. Hypothermia Presenting in Wernicke Encephalopathy: A Case Report

    PubMed Central

    2017-01-01

    Wernicke encephalopathy (WE) is a neurologic disorder characterized by clinical symptoms, such as nystagmus, ataxia, and mental confusion. Hypothermia in patients with WE is a rare complication, and its pathogenic mechanism and therapy are yet to be ascertained. Herein, we presented a case of a 61-year-old man who was diagnosed with WE 3 months earlier. We investigated the cause of hypothermia (35.0℃) that occurred after an enema (bowel emptying). Brain magnetic resonance imaging revealed mammillary body and hypothalamus atrophy. In the autonomic function test, the sympathetic skin response (SSR) test did not evoke SSR latencies on both hands. In addition, abnormal orthostatic hypotension was observed. Laxative and stool softener medication were administered, and his diet was modified, which led to an improvement in constipation after 2 weeks. Moreover, there was no recurrence of hypothermic episode. This is the first reported case of late-onset hypothermia secondary to WE. PMID:28289649

  7. Postmortem computed tomography lung findings in fatal of hypothermia.

    PubMed

    Hyodoh, Hideki; Watanabe, Satoshi; Katada, Ryuichi; Hyodoh, Kazusa; Matsumoto, Hiroshi

    2013-09-10

    To identify lung findings specific to fatal hypothermia on postmortem computed tomography (CT) imaging. Whole body CT scans were performed followed by full autopsy to investigate causes of death. There were 13 fatal hypothermia cases (group A) and 118 with other causes of death (group B). The chest cavity (CC), dead space including fluid/pneumothorax (DS), aerated lung volume (ALV), percentage aerated lung (%ALV), and tracheal aerated volume (ATV) were measured. Autopsy findings of groups A and B were compared. Receiver operating characteristics (ROC) curves were used to identify factors specific to fatal hypothermia. There were no differences in age, sex, number with emphysema, or time from death to CT examination between the 2 groups. CC, DS, ALV, %ALV, and ATV were 2601.0±247.4 (mL), 281.1±136.5 (mL), 1564.5±281.1 (mL), 62.1±6.2(%), and 21.8±2.7 (mL) in group A and 2339.2±67.7 (mL), 241.1±38.0 (mL), 739.9±67.0 (mL), 31.4±2.3(%), and 15.9±0.8 (mL) in group B, respectively. There were statistically significant differences between groups A and B in ALV, %ALV and ATV. The multiple comparison procedure revealed that ALV and %ALV differed significantly between fatal hypothermia and other causes of death (p<0.05). Using ROC evaluation, %ALV had the largest area under the curve (0.819). This study demonstrates that the %ALV is greater in fatal hypothermia cases than in those with other causes of death on postmortem CT chest imaging. Based on CT, hypothermia is very likely to be the cause of death if the %ALV is >70%.

  8. Therapeutic Hypothermia and the Risk of Hemorrhage

    PubMed Central

    Wang, Chih-Hung; Chen, Nai-Chuan; Tsai, Min-Shan; Yu, Ping-Hsun; Wang, An-Yi; Chang, Wei-Tien; Huang, Chien-Hua; Chen, Wen-Jone

    2015-01-01

    Abstract Current guidelines recommend a period of moderate therapeutic hypothermia (TH) for comatose patients after cardiac arrest to improve clinical outcomes. However, in-vitro studies have reported platelet dysfunction, thrombocytopenia, and coagulopathy, results that might discourage clinicians from applying TH in clinical practice. We aimed to quantify the risks of hemorrhage observed in clinical studies. Medline and Embase were searched from inception to October 2015. Randomized controlled trials (RCTs) comparing patients undergoing TH with controls were selected, irrespective of the indications for TH. There were no restrictions for language, population, or publication year. Data on study characteristics, which included patients, details of intervention, and outcome measures, were extracted. Forty-three trials that included 7528 patients were identified from 2692 potentially relevant references. Any hemorrhage was designated as the primary outcome and was reported in 28 studies. The pooled results showed no significant increase in hemorrhage risk associated with TH (risk difference [RD] 0.005; 95% confidence interval [CI] −0.001–0.011; I2, 0%). Among secondary outcomes, patients undergoing TH were found to have increased risk of thrombocytopenia (RD 0.109; 95% CI 0.038–0.179; I2 57.3%) and transfusion requirements (RD 0.021; 95% CI 0.003–0.040; I2 0%). The meta-regression analysis indicated that prolonged duration of cooling may be associated with increased risk of hemorrhage. TH was not associated with increased risk of hemorrhage despite the increased risk of thrombocytopenia and transfusion requirements. Clinicians should cautiously assess each patient's risk-benefit profile before applying TH. PMID:26632746

  9. [Prolonged therapeutic hypothermia after pericardial effusion drain surgery].

    PubMed

    Román Fernández, A; López Álvarez, A; Barreiro Canosa, J L; Varela García, O; Fossati Puertas, S; Pereira Tamayo, J Á

    2014-01-01

    Therapeutic hypothermia is an effective treatment for neurological protection after out-of-hospital cardiac arrest, and may also be beneficial for in-hospital cardiac arrest. Its use is limited in post-surgical patients due to the risk of specific complications, particularly bleeding. There are significant differences among previous publications regarding the time to reach the target temperature and the duration of therapy, so the optimal strategy is not yet established. We present the case of a patient who suffered a perioperative cardiac arrest related to a pericardial tamponade, and who underwent therapeutic hypothermia for 48h.

  10. On the role of brain 5-HT7 receptor in the mechanism of hypothermia: comparison with hypothermia mediated via 5-HT1A and 5-HT3 receptor.

    PubMed

    Naumenko, Vladimir S; Kondaurova, Elena M; Popova, Nina K

    2011-12-01

    Intracerebroventricular administration of selective agonist of serotonin 5-HT(7) receptor LP44 (4-[2-(methylthio)phenyl]-N-(1,2,3,4-tetrahydro-1-naphthalenyl)-1-pyperasinehexanamide hydrochloride; 10.3, 20.5 or 41.0 nmol) produced considerable hypothermic response in CBA/Lac mice. LP44-induced (20.5 nmol) hypothermia was significantly attenuated by the selective 5-HT(7) receptor antagonist SB 269970 (16.1 fmol, i.c.v.) pretreatment. At the same time, intraperitoneal administration of LP44 in a wide range of doses 1.0, 2.0 or 10.0 mg/kg (2.0, 4.0, 20.0 μmol/kg) did not cause considerable hypothermic response. These findings indicate the implication of central, rather than peripheral 5-HT(7) receptors in the regulation of hypothermia. The comparison of LP44-induced (20.5 nmol) hypothermic reaction in eight inbred mouse strains (DBA/2J, CBA/Lac, C57BL/6, BALB/c, ICR, AKR/J, C3H and Asn) was performed and a significant effect of genotype was found. In the same eight mouse strains, functional activity of 5-HT(1A) and 5-HT(3) receptors was studied. The comparison of hypothermic responses produced by 5-HT(7) receptor agonist LP44 (20.5 nmol, i.c.v.) and 5-HT(1A) receptor agonist 8-OH-DPAT 1.0 mg/kg, i.p. (3.0 μmol/kg), 5-HT(3) receptor agonist m-CPBG (40.0 nmol, i.c.v.) did not reveal considerable interstrain correlations between 5-HT(7) and 5-HT(1A) or 5-HT(3) receptor-induced hypothermia. The selective 5-HT(7) receptor antagonist SB 269970 (16.1 fmol, i.c.v.) failed to attenuate the hypothermic effect of 8-OH-DPAT 1.0 mg/kg, i.p. (3.0 μmol/kg) and m-CPBG (40.0 nmol, i.c.v.) indicating that the brain 5-HT(7) receptor is not involved in the hypothermic effects of 8-OH-DPAT or m-CPBG. The obtained results suggest that the central 5-HT(7) receptor plays an essential role in the mediation of thermoregulation independent of 5-HT(1A) and 5-HT(3) receptors.

  11. Intracoronary hypothermia for acute myocardial infarction in the isolated beating pig heart

    PubMed Central

    Otterspoor, Luuk C; van Nunen, Lokien X; Rosalina, Tilaï T; Veer, Marcel van’t; Tuijl, Sjoerd Van; Stijnen, Marco; Rutten, Marcel CM; van de Vosse, Frans N; Pijls, Nico HJ

    2017-01-01

    Hypothermia may attenuate reperfusion injury and thereby improve acute myocardial infarction therapy. Systemic cooling trials failed to reduce infarct size, perhaps because the target temperature was not reached fast enough. The use of selective intracoronary hypothermia combined with intracoronary temperature monitoring allows for titrating to target temperature and optimizing the cooling rate. We aimed to the test the feasibility of intracoronary cooling for controlled, selective myocardial hypothermia in an isolated beating pig heart. In five porcine hearts the left anterior descending artery (LAD) was occluded by an over-the-wire balloon (OTWB). After occlusion, saline at 22°C was infused through the OTWB lumen for 5 minutes into the infarct area at a rate of 30 ml/min. Thereafter the balloon was deflated but infusion continued with saline at 4°C for 5 minutes. Distal coronary temperature was continuously monitored by a pressure/temperature guidewire. Myocardial temperature at several locations in the infarct and control areas was recorded using needle thermistors. In the occlusion phase, coronary temperature decreased by 11.4°C (range 9.4-12.5°C). Myocardial temperature throughout the infarct area decreased by 5.1°C (range 1.8-8.1°C) within three minutes. During the reperfusion phase, coronary temperature decreased by 6.2°C (range 4.1-10.3°C) and myocardial temperature decreased by 4.5°C (range 1.5-7.4°C). Myocardial temperature outside the infarct area was not affected. In the isolated beating pig heart with acute occlusion of the LAD, we were able to rapidly “induce, maintain, and control” a stable intracoronary and myocardial target temperature of at least 4°C below body temperature without side effects and using standard PCI equipment, justifying further studies of this technique in humans. PMID:28337283

  12. Cerebral vasoreactivity to carbon dioxide during cardiopulmonary perfusion at normothermia and hypothermia

    SciTech Connect

    Johnsson, P.; Messeter, K.; Ryding, E.; Kugelberg, J.; Stahl, E. )

    1989-12-01

    With the pH-stat acid-base regulation strategy during hypothermic cardiopulmonary bypass (CPB), carbon dioxide (CO{sub 2}) is generally administered to maintain the partial pressure of arterial CO{sub 2} at a higher level than with the alpha-stat method. With preserved CO{sub 2} vasoreactivity during CPB, this induction of respiratory acidosis can lead to a much higher cerebral blood flow level than is motivated metabolically. To evaluate CO{sub 2} vasoreactivity, cerebral blood flow was measured using a xenon 133 washout technique before, during, and after CPB at different CO{sub 2} levels in patients who were undergoing coronary artery bypass grafting with perfusion at either hypothermia or normothermia. The overall CO{sub 2} reactivity was 1.2 mL/100 g/min/mm Hg. There was no difference between the groups. The CO{sub 2} reactivity was not affected by temperature or CPB. The induced hemodilution resulted in higher cerebral blood flow levels during CPB, although this was counteracted by the temperature-dependent decrease in the hypothermia group. After CPB, a transient increase in cerebral blood flow was noted in the hypothermia group, the reason for which remains unclear. The study shows that manipulation of the CO{sub 2} level at different temperatures results in similar changes in cerebral blood flow irrespective of the estimated metabolic demand. This finding further elucidates the question of whether alpha-stat or pH-stat is the most physiological way to regulate the acid-base balance during hypothermic CPB.

  13. Early clinical prediction of neurological outcome following out of hospital cardiac arrest managed with therapeutic hypothermia

    PubMed Central

    Ruknuddeen, Mohammed Ishaq; Ramadoss, Rajaram; Rajajee, V.; Grzeskowiak, Luke E.; Rajagopalan, Ram E.

    2015-01-01

    Background: Therapeutic hypothermia (TH) may improve neurological outcome in comatose patients following out of hospital cardiac arrest (OHCA). The reliability of clinical prediction of neurological outcome following TH remains unclear. In particular, there is very limited data on survival and predictors of neurological outcome following TH for OHCA from resource-constrained settings in general and South Asia in specific. Objective: The objective was to identify factors predicting unfavorable neurological outcome at hospital discharge in comatose survivors of OHCA treated with hypothermia. Design: Retrospective chart review. Setting: Urban 200-bed hospital in Chennai, India. Methods: Predictors of unfavorable neurological outcome (cerebral performance category score [3–5]) at hospital discharge were evaluated among patients admitted between January 2006 and December 2012 following OHCA treated with TH. Hypothermia was induced with cold intravenous saline bolus, ice packs and cold-water spray with bedside fan. Predictors of unfavorable neurological outcome were examined through multivariate exact logistic regression analysis. Results: A total of 121 patients were included with 106/121 (87%) experiencing the unfavorable neurological outcome. Independent predictors of unfavorable neurological outcome included: Status myoclonus <24 h (odds ratio [OR] 21.79, 95% confidence interval [CI] 2.89-Infinite), absent brainstem reflexes (OR 50.09, 6.55-Infinite), and motor response worse than flexion on day 3 (OR 99.41, 12.21-Infinite). All 3 variables had 100% specificity and positive predictive value. Conclusion: Status myoclonus within 24 h, absence of brainstem reflexes and motor response worse than flexion on day 3 reliably predict unfavorable neurological outcome in comatose patients with OHCA treated with TH. PMID:26195855

  14. The Social Epidemiology of Accidental Hypothermia among the Aged.

    ERIC Educational Resources Information Center

    Rango, Nicholas

    1985-01-01

    Describes the 1970-1979 incidence of exposure-related hypothermia deaths in the United States. Showed nonwhite men at highest and white women at lowest risk at all ages. Age-related impairment in theromoregulation, functional disability, poverty, and social isolation were found to increase elderly individual's susceptibility to this environmental…

  15. Severe Hypothermia Causing Ventricular Arrhythmia in Organophosphorus Poisoning.

    PubMed

    Munta, Kartik; Santosh, Paiullah; Surath, Manimala Rao

    2017-02-01

    Organophosphorus poisoning cases are routinely treated across all Intensive Care Units adjoining the rural areas where agriculture is the main source of income. We present a unique case of severe hypothermia seen in a case of organophosphorus poisoning, which led to electrocardiogram disturbances and life-threatening arrhythmias.

  16. Severe Hypothermia Causing Ventricular Arrhythmia in Organophosphorus Poisoning

    PubMed Central

    Munta, Kartik; Santosh, Paiullah; Surath, Manimala Rao

    2017-01-01

    Organophosphorus poisoning cases are routinely treated across all Intensive Care Units adjoining the rural areas where agriculture is the main source of income. We present a unique case of severe hypothermia seen in a case of organophosphorus poisoning, which led to electrocardiogram disturbances and life-threatening arrhythmias. PMID:28250607

  17. Chronic hypothermia and water intoxication associated with a neurodegenerative disease.

    PubMed Central

    Corbett, E. L.; Sisodiya, S.; Sarkar, D.

    1993-01-01

    We describe a 71 year old man with a neurodegenerative condition who developed chronic inappropriate antidiuretic hormone secretion and hypothermia resulting in recurrent episodes of impaired consciousness. This combination of abnormalities is attributable to hypothalamic disease and has not to our knowledge been previously reported with clearly documented antidiuretic hormone excess. Images Figure 1 PMID:8121871

  18. Prevention and Management of Neonatal Hypothermia in Rural Zambia

    PubMed Central

    Lunze, Karsten; Yeboah-Antwi, Kojo; Marsh, David R.; Kafwanda, Sarah Ngolofwana; Musso, Austen; Semrau, Katherine; Waltensperger, Karen Z.; Hamer, Davidson H.

    2014-01-01

    Background Neonatal hypothermia is increasingly recognized as a risk factor for newborn survival. The World Health Organization recommends maintaining a warm chain and skin-to-skin care for thermoprotection of newborn children. Since little is known about practices related to newborn hypothermia in rural Africa, this study's goal was to characterize relevant practices, attitudes, and beliefs in rural Zambia. Methods and Findings We conducted 14 focus group discussions with mothers and grandmothers and 31 in-depth interviews with community leaders and health officers in Lufwanyama District, a rural area in the Copperbelt Province, Zambia, enrolling a total of 171 participants. We analyzed data using domain analysis. In rural Lufwanyama, community members were aware of the danger of neonatal hypothermia. Caregivers' and health workers' knowledge of thermoprotective practices included birthplace warming, drying and wrapping of the newborn, delayed bathing, and immediate and exclusive breastfeeding. However, this warm chain was not consistently maintained in the first hours postpartum, when newborns are at greatest risk. Skin-to-skin care was not practiced in the study area. Having to assume household and agricultural labor responsibilities in the immediate postnatal period was a challenge for mothers to provide continuous thermal care to their newborns. Conclusions Understanding and addressing community-based practices on hypothermia prevention and management might help improve newborn survival in resource-limited settings. Possible interventions include the implementation of skin-to-skin care in rural areas and the use of appropriate, low-cost newborn warmers to prevent hypothermia and support families in their provision of newborn thermal protection. Training family members to support mothers in the provision of thermoprotection for their newborns could facilitate these practices. PMID:24714630

  19. Therapeutic hypothermia for the treatment of acute myocardial infarction-combined analysis of the RAPID MI-ICE and the CHILL-MI trials.

    PubMed

    Erlinge, David; Götberg, Matthias; Noc, Marko; Lang, Irene; Holzer, Michael; Clemmensen, Peter; Jensen, Ulf; Metzler, Bernhard; James, Stefan; Bøtker, Hans Erik; Omerovic, Elmir; Koul, Sasha; Engblom, Henrik; Carlsson, Marcus; Arheden, Håkan; Östlund, Ollie; Wallentin, Lars; Klos, Bradley; Harnek, Jan; Olivecrona, Göran K

    2015-06-01

    In the randomized rapid intravascular cooling in myocardial infarction as adjunctive to percutaneous coronary intervention (RAPID MI-ICE) and rapid endovascular catheter core cooling combined with cold saline as an adjunct to percutaneous coronary intervention for the treatment of acute myocardial infarction CHILL-MI studies, hypothermia was rapidly induced in conscious patients with ST-elevation myocardial infarction (STEMI) by a combination of cold saline and endovascular cooling. Twenty patients in RAPID MI-ICE and 120 in CHILL-MI with large STEMIs, scheduled for primary percutaneous coronary intervention (PCI) within <6 hours after symptom onset were randomized to hypothermia induced by rapid infusion of 600-2000 mL cold saline combined with endovascular cooling or standard of care. Hypothermia was initiated before PCI and continued for 1-3 hours after reperfusion aiming at a target temperature of 33°C. The primary endpoint was myocardial infarct size (IS) as a percentage of myocardium at risk (IS/MaR) assessed by cardiac magnetic resonance imaging at 4±2 days. Patients randomized to hypothermia treatment achieved a mean core body temperature of 34.7°C before reperfusion. Although significance was not achieved in CHILL-MI, in the pooled analysis IS/MaR was reduced in the hypothermia group, relative reduction (RR) 15% (40.5, 28.0-57.6 vs. 46.6, 36.8-63.8, p=0.046, median, interquartile range [IQR]). IS/MaR was predominantly reduced in early anterior STEMI (0-4h) in the hypothermia group, RR=31% (40.5, 28.8-51.9 vs. 59.0, 45.0-67.8, p=0.01, median, IQR). There was no mortality in either group. The incidence of heart failure was reduced in the hypothermia group (2 vs. 11, p=0.009). Patients with large MaR (>30% of the left ventricle) exhibited significantly reduced IS/MaR in the hypothermia group (40.5, 27.0-57.6 vs. 55.1, 41.1-64.4, median, IQR; hypothermia n=42 vs. control n=37, p=0.03), while patients with MaR<30% did not show effect of hypothermia (35

  20. Pressure Infusion Cuff and Blood Warmer during Massive Transfusion: An Experimental Study About Hemolysis and Hypothermia

    PubMed Central

    Pruneau, Denise; Dorval, Josée; Thibault, Louis; Fisette, Jean-François; Bédard, Suzanne K.; Jacques, Annie; Beauregard, Patrice

    2016-01-01

    Background Blood warmers were developed to reduce the risk of hypothermia associated with the infusion of cold blood products. During massive transfusion, these devices are used with compression sleeve, which induce a major stress to red blood cells. In this setting, the combination of blood warmer and compression sleeve could generate hemolysis and harm the patient. We conducted this study to compare the impact of different pressure rates on the hemolysis of packed red blood cells and on the outlet temperature when a blood warmer set at 41.5°C is used. Methods Pressure rates tested were 150 and 300 mmHg. Ten packed red blood cells units were provided by Héma-Québec and each unit was sequentially tested. Results We found no increase in hemolysis either at 150 or 300 mmHg. By cons, we found that the blood warmer was not effective at warming the red blood cells at the specified temperature. At 150 mmHg, the outlet temperature reached 37.1°C and at 300 mmHg, the temperature was 33.7°C. Conclusion To use a blood warmer set at 41.5°C in conjunction with a compression sleeve at 150 or 300 mmHg does not generate hemolysis. At 300 mmHg a blood warmer set at 41.5°C does not totally avoid a risk of hypothermia. PMID:27711116

  1. Behavioral hypothermia of a domesticated lizard under treatment of the hypometabolic agent 3-iodothyronamine.

    PubMed

    Ha, Kyoungbong; Shin, Haksup; Ju, Hyunwoo; Chung, Chan-Moon; Choi, Inho

    2016-10-31

    Ectothermic animals rely on behavioral thermoregulation due to low capacity of heat production and storage. Previously, lizards were shown to achieve 'fever' during microbial infection by increasing their preferred body temperature (PBT) behaviorally, thereby attaining a relatively high survival rate. The purpose of this study was to investigate whether domesticated lizards pursued 'behavioral hypothermia' induced by a hypometabolic agent 3-iodothyronamine (T1AM). We found that treatment with 8.0 mg/kg T1AM caused a lizard species, the leopard gecko (Eublepharis macularius), to decrease its ventilation and oxygen consumption rates 0.64- and 0.76-fold, respectively, compared to those of the control (P<0.05). The lizards, habituated at an ambient temperature of 30 ± 0.5°C, also showed a significant decrease in the PBT range over a freely accessible thermal gradient between 5°C and 45°C. The upper limit of the PBT in the treated lizards lowered from 31.9° to 30.6°C, and the lower limit from 29.5° to 26.3°C (P<0.001). These findings demonstrate that the treated lizards pursued behavioral hypothermia in conjunction with hypoventilation and hypometabolism. Because prior studies reported a similar hypometabolic response in T1AM-injected laboratory mice, the domesticated lizards, as a part of the vertebrate phylogeny, may be a useful laboratory model for biological and pharmacological researches such as drug potency test.

  2. Hypothermia for severe traumatic brain injury in adults: Recent lessons from randomized controlled trials

    PubMed Central

    Shaefi, Shahzad; Mittel, Aaron M.; Hyam, Jonathan A.; Boone, M. Dustin; Chen, Clark C.; Kasper, Ekkehard M.

    2016-01-01

    Background: Traumatic brain injury (TBI) is a worldwide health concern associated with significant morbidity and mortality. In the United States, severe TBI is managed according to recommendations set forth in 2007 by the Brain Trauma Foundation (BTF), which were based on relatively low quality clinical trials. These guidelines prescribed the use of hypothermia for the management of TBI. Several randomized controlled trials (RCTs) of hypothermia for TBI have since been conducted. Despite this new literature, there is ongoing controversy surrounding the use of hypothermia for the management of severe TBI. Methods: We searched the PubMed database for all RCTs of hypothermia for TBI since 2007 with the intent to review the methodology outcomes of these trials. Furthermore, we aimed to develop evidence-based, expert opinions based on these recent studies. Results: We identified 8 RCTs of therapeutic hypothermia published since 2007 that focused on changes in neurologic outcomes or mortality in patients with severe TBI. The majority of these trials did not identify improvement with the use of hypothermia, though there were subgroups of patients that may have benefited from hypothermia. Differences in methodology prevented direct comparison between studies. Conclusions: A growing body of literature disfavors the use of hypothermia for the management of severe TBI. In general, empiric hypothermia for severe TBI should be avoided. However, based on the results of recent trials, there may be some patients, such as those in Asian centers or with focal neurologic injury, who may benefit from hypothermia. PMID:28168089

  3. Intracranial pressure elevation after ischemic stroke in rats: cerebral edema is not the only cause, and short-duration mild hypothermia is a highly effective preventive therapy

    PubMed Central

    Murtha, Lucy A; McLeod, Damian D; Pepperall, Debbie; McCann, Sarah K; Beard, Daniel J; Tomkins, Amelia J; Holmes, William M; McCabe, Christopher; Macrae, I Mhairi; Spratt, Neil J

    2015-01-01

    In both the human and animal literature, it has largely been assumed that edema is the primary cause of intracranial pressure (ICP) elevation after stroke and that more edema equates to higher ICP. We recently demonstrated a dramatic ICP elevation 24 hours after small ischemic strokes in rats, with minimal edema. This ICP elevation was completely prevented by short-duration moderate hypothermia soon after stroke. Here, our aims were to determine the importance of edema in ICP elevation after stroke and whether mild hypothermia could prevent the ICP rise. Experimental stroke was performed in rats. ICP was monitored and short-duration mild (35 °C) or moderate (32.5 °C) hypothermia, or normothermia (37 °C) was induced after stroke onset. Edema was measured in three studies, using wet–dry weight calculations, T2-weighted magnetic resonance imaging, or histology. ICP increased 24 hours after stroke onset in all normothermic animals. Short-duration mild or moderate hypothermia prevented this rise. No correlation was seen between ΔICP and edema or infarct volumes. Calculated rates of edema growth were orders of magnitude less than normal cerebrospinal fluid production rates. These data challenge current concepts and suggest that factors other than cerebral edema are the primary cause of the ICP elevation 24 hours after stroke onset. PMID:25515213

  4. Dopamine treatment attenuates acute kidney injury in a rat model of deep hypothermia and rewarming - The role of renal H2S-producing enzymes.

    PubMed

    Dugbartey, George J; Talaei, Fatemeh; Houwertjes, Martin C; Goris, Maaike; Epema, Anne H; Bouma, Hjalmar R; Henning, Robert H

    2015-12-15

    Hypothermia and rewarming produces organ injury through the production of reactive oxygen species. We previously found that dopamine prevents hypothermia and rewarming-induced apoptosis in cultured cells through increased expression of the H2S-producing enzyme cystathionine β-Synthase (CBS). Here, we investigate whether dopamine protects the kidney in deep body cooling and explore the role of H2S-producing enzymes in an in vivo rat model of deep hypothermia and rewarming. In anesthetized Wistar rats, body temperature was decreased to 15°C for 3h, followed by rewarming for 1h. Rats (n≥5 per group) were treated throughout the procedure with vehicle or dopamine infusion, and in the presence or absence of a non-specific inhibitor of H2S-producing enzymes, amino-oxyacetic acid (AOAA). Kidney damage and renal expression of three H2S-producing enzymes (CBS, CSE and 3-MST) was quantified and serum H2S level measured. Hypothermia and rewarming induced renal damage, evidenced by increased serum creatinine, renal reactive oxygen species production, KIM-1 expression and influx of immune cells, which was accompanied by substantially lowered renal expression of CBS, CSE, and 3-MST and lowered serum H2S levels. Infusion of dopamine fully attenuated renal damage and maintained expression of H2S-producing enzymes, while normalizing serum H2S. AOAA further decreased the expression of H2S-producing enzymes and serum H2S level, and aggravated renal damage. Hence, dopamine preserves renal integrity during deep hypothermia and rewarming likely by maintaining the expression of renal H2S-producing enzymes and serum H2S.

  5. Characterization of Death in Neonatal Encephalopathy in the Hypothermia Era.

    PubMed

    Lemmon, Monica E; Boss, Renee D; Bonifacio, Sonia L; Foster-Barber, Audrey; Barkovich, A James; Glass, Hannah C

    2017-03-01

    This study aimed to characterize the circumstances of death in encephalopathic neonates treated with therapeutic hypothermia. Patients who died after or during treatment with therapeutic hypothermia between 2007-2014 were identified. Patient circumstance of death was characterized using an established paradigm. Thirty-one of 229 patients died (14%) at a median of 3 days of life. Most who died were severely encephalopathic on examination (90%) and had severely abnormal electroencephalographic (EEG) findings (87%). All those who had magnetic resonance images (n = 13) had evidence of moderate-severe brain injury; 6 had near-total brain injury. Cooling was discontinued prematurely in 61% of patients. Most patients (90%) were physiologically stable at the time of death; 81% died following elective extubation for quality of life considerations. Three patients (10%) died following withholding or removal of artificial hydration and nutrition. Characterization of death in additional cohorts is needed to identify differences in decision making practices over time and between centers.

  6. Coagulopathy by Hypothermia and Acidosis: Mechanisms of Thrombin Generation and Fibrinogen Availability

    DTIC Science & Technology

    2009-07-01

    models in swines are based on concepts and procedures developed previously in other animals, particularly the dog; yet, they are superior to canine...degradation via different mech- anisms. Despite the differential effects, hypothermia and acido - sis lead to a consistent outcome: deficit in...hypothermia and acidoses revisited. J Trauma. 1997;42:857–861; discussion 861–862. 4. Ferrara A, MacArthur JD, Wright HK, Modlin IM, McMillen MA. Hypothermia

  7. Study on Control of Brain Temperature for Brain Hypothermia Treatment

    NASA Astrophysics Data System (ADS)

    Gaohua, Lu; Wakamatsu, Hidetoshi

    The brain hypothermia treatment is an attractive therapy for the neurologist because of its neuroprotection in hypoxic-ischemic encephalopathy patients. The present paper deals with the possibility of controlling the brain and other viscera in different temperatures from the viewpoint of system control. It is theoretically attempted to realize the special brain hypothermia treatment to cool only the head but to warm the body by using the simple apparatus such as the cooling cap, muffler and warming blanket. For this purpose, a biothermal system concerning the temperature difference between the brain and the other thoracico-abdominal viscus is synthesized from the biothermal model of hypothermic patient. The output controllability and the asymptotic stability of the system are examined on the basis of its structure. Then, the maximum temperature difference to be realized is shown dependent on the temperature range of the apparatus and also on the maximum gain determined from the coefficient matrices A, B and C of the biothermal system. Its theoretical analysis shows the realization of difference of about 2.5°C, if there is absolutely no constraint of the temperatures of the cooling cap, muffler and blanket. It is, however, physically unavailable. Those are shown by simulation example of the optimal brain temperature regulation using a standard adult database. It is thus concluded that the surface cooling and warming apparatus do no make it possible to realize the special brain hypothermia treatment, because the brain temperature cannot be cooled lower than those of other viscera in an appropriate temperature environment. This study shows that the ever-proposed good method of clinical treatment is in principle impossible in the actual brain hypothermia treatment.

  8. Accidental hypothermia and death from cold in urban areas

    NASA Astrophysics Data System (ADS)

    Tanaka, Masatoshi; Tokudome, Shogo

    1991-12-01

    Hypothermia is considered a sericus problem in big cities. In order to clarify factors contributing to urban hypothermia and death from cold which will continue to be an issue in cities in the future, we analyzed autopsy reports recorded in the Tokyo Medical Examiner's Office from 1974 to 1983. In a total of 18346 autopsy reports 157 deaths had been diagnosed as due to exposure to cold. Of these cases, the greatest number were males in their forties and fifties, and most of these were inebriated and/or homeless. Eighty-four perent of urban hypothermia cases occurred when the outdoor temperature was below 5°C, and 50% of deaths from cold occurred when the outdoor temperature was between 0° and 5°C. There were no incidences of death from cold when the minimum outdoor temperature had remained above 16°C. Seventy-four percent of deaths from cold occurred during the winter months of December, January and February, and most of the remaining deaths occurred in March and November. There were no deaths from cold from June to August. More than half of all deaths from cold occurred from 3.00 a.m. to 9.00 a.m., with the peak occurring at 5.00 a.m. A blood alcohol concentration of over 2.5 mg/ml had often been found in those in their forties and fifties who had died from hypothermia, and autopsy had often revealed disorders of the liver, digestive system, and circulatory system. Chronic lesions of the liver, probably due to alcoholism, were found in many cases; few cases showed no evidence of alcoholism and these were significantly different from the former group.

  9. Repeated administration of phytocannabinoid Δ(9)-THC or synthetic cannabinoids JWH-018 and JWH-073 induces tolerance to hypothermia but not locomotor suppression in mice, and reduces CB1 receptor expression and function in a brain region-specific manner.

    PubMed

    Tai, S; Hyatt, W S; Gu, C; Franks, L N; Vasiljevik, T; Brents, L K; Prather, P L; Fantegrossi, W E

    2015-12-01

    These studies probed the relationship between intrinsic efficacy and tolerance/cross-tolerance between ∆(9)-THC and synthetic cannabinoid drugs of abuse (SCBs) by examining in vivo effects and cellular changes concomitant with their repeated administration in mice. Dose-effect relationships for hypothermic effects were determined in order to confirm that SCBs JWH-018 and JWH-073 are higher efficacy agonists than ∆(9)-THC in mice. Separate groups of mice were treated with saline, sub-maximal hypothermic doses of JWH-018 or JWH-073 (3.0mg/kg or 10.0mg/kg, respectively) or a maximally hypothermic dose of 30.0mg/kg ∆(9)-THC once per day for 5 consecutive days while core temperature and locomotor activity were monitored via biotelemetry. Repeated administration of all drugs resulted in tolerance to hypothermic effects, but not locomotor effects, and this tolerance was still evident 14 days after the last drug administration. Further studies treated mice with 30.0mg/kg ∆(9)-THC once per day for 4 days, then tested with SCBs on day 5. Mice with a ∆(9)-THC history were cross-tolerant to both SCBs, and this cross-tolerance also persisted 14 days after testing. Select brain regions from chronically treated mice were examined for changes in CB1 receptor expression and function. Expression and function of hypothalamic CB1Rs were reduced in mice receiving chronic drugs, but cortical CB1R expression and function were not altered. Collectively, these data demonstrate that repeated ∆(9)-THC, JWH-018 and JWH-073 can induce long-lasting tolerance to some in vivo effects, which is likely mediated by region-specific downregulation and desensitization of CB1Rs.

  10. Effects of perioperative hypothermia and warming in surgical practice.

    PubMed

    Kumar, Senthil; Wong, Peng Foo; Melling, Andrew Christian; Leaper, David John

    2005-09-01

    Perioperative hypothermia is common and adversely affects clinical outcomes due to its effect on a range of homeostatic functions. Many of these adverse consequences are preventable by the use of warming techniques. A literature search was conducted to identify relevant published articles on perioperative hypothermia and warming. The databases searched include MEDLINE (1966 to February 2005), EMBASE (1974 to February 2005), CINAHL, the Cochrane library and the health technology assessment database. Reference lists of key articles were also searched. The primary beneficial effects of warming are mediated through increased blood flow and oxygen tension at tissue level. Reduction in wound infection, blood loss and perioperative pain with warming is promising. However, more evidence from good-quality prospective randomised controlled trials is needed to evaluate the role of warming in improving overall morbidity, mortality and hospital stay as well as to clarify its role as an adjunct to resuscitation and during the pre-hospital transport phase of critically ill patients. Awareness of the risks of perioperative hypothermia is the key to prevention. Achieving normothermia throughout the patient's journey is a worthwhile goal in surgical patients.

  11. 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.

  12. Therapeutic Hypothermia in Stroke and Traumatic Brain Injury

    PubMed Central

    Faridar, Alireza; Bershad, Eric M.; Emiru, Tenbit; Iaizzo, Paul A.; Suarez, Jose I.; Divani, Afshin A.

    2011-01-01

    Therapeutic hypothermia (TH) is considered to improve survival with favorable neurological outcome in the case of global cerebral ischemia after cardiac arrest and perinatal asphyxia. The efficacy of hypothermia in acute ischemic stroke (AIS) and traumatic brain injury (TBI), however, is not well studied. Induction of TH typically requires a multimodal approach, including the use of both pharmacological agents and physical techniques. To date, clinical outcomes for patients with either AIS or TBI who received TH have yielded conflicting results; thus, no adequate therapeutic consensus has been reached. Nevertheless, it seems that by determining optimal TH parameters and also appropriate applications, cooling therapy still has the potential to become a valuable neuroprotective intervention. Among the various methods for hypothermia induction, intravascular cooling (IVC) may have the most promise in the awake patient in terms of clinical outcomes. Currently, the IVC method has the capability of more rapid target temperature attainment and more precise control of temperature. However, this technique requires expertise in endovascular surgery that can preclude its application in the field and/or in most emergency settings. It is very likely that combining neuroprotective strategies will yield better outcomes than utilizing a single approach. PMID:22207862

  13. Effect of wet-cold weather transportation conditions on thermoregulation and the development of accidental hypothermia in pullets under tropical conditions.

    PubMed

    Minka, Ndazo S; Ayo, Joseph O

    2016-03-01

    The present study examines onboard thermal microclimatic conditions and thermoregulation of pullets exposed to accidental hypothermia during wet-cold weather transportation conditions, and the effect of rewarming on colonic temperature (CT) of the birds immediately after transportation. A total of 2200 pullets were transportation for 5 h in two separate vehicles during the nighttime. The last 3 h of the transportation period was characterized by heavy rainfall. During the precipitation period, each vehicle was covered one fourth way from the top-roof with a tarpaulin. The onboard thermal conditions inside the vehicles during transportation, which comprised ambient temperature and relative humidity were recorded, while humidity ratio and specific enthalpy were calculated. The CT of the birds was recorded before and after transportation. During transportation, onboard thermal heterogeneity was observed inside the vehicles with higher (p < 0.05) values in the front and center, and lower values recorded at the air inlets at the sides and rear planes. The CT values recorded in birds at the front and center planes were between 42.2 and 42.5 °C, indicative of mild hypothermia; while lower CT values between 28 and 38 °C were recorded at the sides and rear planes, indicative of mild to severe hypothermia. Several hours of gradual rewarming returned the CT to normal range. The result, for the first time, demonstrated the occurrence of accidental hypothermia in transported pullets under tropical conditions and a successful rewarming outcome. In conclusion, transportation of pullets during wet weather at onboard temperature of 18-20 °C induced hypothermia on birds located at the air inlets, which recovered fully after several hours of gradual rewarming.

  14. Effect of wet-cold weather transportation conditions on thermoregulation and the development of accidental hypothermia in pullets under tropical conditions

    NASA Astrophysics Data System (ADS)

    Minka, Ndazo S.; Ayo, Joseph O.

    2016-03-01

    The present study examines onboard thermal microclimatic conditions and thermoregulation of pullets exposed to accidental hypothermia during wet-cold weather transportation conditions, and the effect of rewarming on colonic temperature (CT) of the birds immediately after transportation. A total of 2200 pullets were transportation for 5 h in two separate vehicles during the nighttime. The last 3 h of the transportation period was characterized by heavy rainfall. During the precipitation period, each vehicle was covered one fourth way from the top-roof with a tarpaulin. The onboard thermal conditions inside the vehicles during transportation, which comprised ambient temperature and relative humidity were recorded, while humidity ratio and specific enthalpy were calculated. The CT of the birds was recorded before and after transportation. During transportation, onboard thermal heterogeneity was observed inside the vehicles with higher ( p < 0.05) values in the front and center, and lower values recorded at the air inlets at the sides and rear planes. The CT values recorded in birds at the front and center planes were between 42.2 and 42.5 °C, indicative of mild hypothermia; while lower CT values between 28 and 38 °C were recorded at the sides and rear planes, indicative of mild to severe hypothermia. Several hours of gradual rewarming returned the CT to normal range. The result, for the first time, demonstrated the occurrence of accidental hypothermia in transported pullets under tropical conditions and a successful rewarming outcome. In conclusion, transportation of pullets during wet weather at onboard temperature of 18-20 °C induced hypothermia on birds located at the air inlets, which recovered fully after several hours of gradual rewarming.

  15. History and current use of mild therapeutic hypothermia after cardiac arrest

    PubMed Central

    Alan, David; Vejvoda, Jiri; Honek, Jakub; Veselka, Josef

    2016-01-01

    In spite of many years of development and implementation of pre-hospital advanced life support programmes, the survival rate of out-of-hospital cardiac arrest (OHCA) used to be very poor. Neurologic injury from cerebral hypoxia is the most common cause of death in patients with OHCA. In the past two decades, post-resuscitation care has developed many new concepts aimed at improving the neurological outcome and survival rate of patients after cardiac arrest. Systematic post-cardiac arrest care after the return of spontaneous circulation, including induced mild therapeutic hypothermia (TH) in selected patients, is aimed at significantly improving rates of long-term neurologically intact survival. This review summarises the history and current knowledge in the field of mild TH after OHCA. PMID:27695505

  16. Therapeutic hypothermia impacts leukocyte kinetics after cardiac arrest

    PubMed Central

    Dufner, Matthias C.; Andre, Florian; Stiepak, Jan; Zelniker, Thomas; Chorianopoulos, Emmanuel; Preusch, Michael; Katus, Hugo A.

    2016-01-01

    Background Patients admitted to the hospital after primarily successful cardiopulmonary resuscitation (CPR) are at a very high risk for neurologic deficits and death. Targeted temperature management (TTM) for mild therapeutic hypothermia has been shown to improve survival compared to standard treatment. Acute cardiovascular events, such as myocardial infarction (MI), are a major cause for cardiac arrest (CA) in patients who undergo CPR. Recent findings have demonstrated the importance and impact of the leukocyte response following acute MI. Methods In this retrospective, single center study we enrolled 169 patients with CA due to non-traumatic causes and primarily successful CPR. A total of 111 subjects (66%) underwent TTM aiming for a target temperature of 32–34 °C. Results Analysis of 30 day follow up showed a significantly improved survival of all patients who received TTM compared to patients without hypothermia (P=0.0001). Furthermore TTM was an independent variable of good neurological outcome after 6 months (P=0.0030). Therapeutic hypothermia was found to be beneficial independent of differences in age and sex between both groups. While a higher rate of pneumonia was observed with TTM, this diagnosis had no additional impact on survival or neurological outcome. The beneficial effect on mortality remained significant in patients with the diagnosis of an acute cardiac event (P=0.0145). Next, we evaluated the kinetics of leukocytes in this group over the course of 7 days after CA. At presentation, patients showed a mean level of 16.5±6.7 of leukocytes per microliter. While this level stayed stable in the group of patients without hypothermia, patients who received TTM showed a significant decline of leukocyte levels resulting in significantly lower numbers of leukocytes on days 3 and 5 after CPR. Interestingly, these differences in leukocyte counts remained beyond the time period of TTM while C-reactive protein (CRP) levels were suppressed only during

  17. The geography of hypothermia in the United States: An analysis of mortality, morbidity, thresholds, and messaging

    NASA Astrophysics Data System (ADS)

    Spencer, Jeremy M.

    Hypothermia within the United States has seldom been studied from a geographic perspective. This dissertation assessed the following aspects of hypothermia: 1) A cataloging of Internet web pages containing hypothermia-related guidance, with a summary of the information contained within. The summarized hypothermia information was assessed for scientific validity through an extensive assessment of the peer-reviewed medical literature; 2) the spatio-temporal distribution of hypothermia deaths in U.S. Combined Statistical areas for the years 1979-2004, and their association with National Weather Service windchill advisory and warning thresholds; 3) the spatio-temporal distribution of hypothermia morbidity in the State of New York from 1991-1992 to 2005-2006 and its association with Spatial Synoptic Classification weather types. The results indicate that web-based hypothermia information has generally poor content not supported by the scientific literature, and there are many prominent omissions of well-established hypothermia information. A total of 9,185 hypothermia fatalities attributable to cold exposure occurred in 89 metro areas from 1979 to 2004. The southeastern US had the greatest vulnerability to hypothermia, with high rates of deaths occurring at higher temperatures than northern states. Median windchill temperature associated with deaths was generally latitudinal, with southern deaths occurring at higher temperatures. For all regions, hypothermia deaths occurred at temperatures considerably higher than windchill advisory criteria. Hypothermia morbidity within New York State was associated with long-lasting polar weather types. There are a number of findings common to these three papers. Information about hypothermia tends to be under-communicated (no central location for wind chill alerts, unsupported statements on many websites). Hypothermia deaths and hospitalizations increase when locally cold and long-lasting weather types occur, which fits in with what

  18. Inflammatory effects of hypothermia and inhaled H2S during resuscitated, hyperdynamic murine septic shock.

    PubMed

    Wagner, Florian; Wagner, Katja; Weber, Sandra; Stahl, Bettina; Knöferl, Markus W; Huber-Lang, Markus; Seitz, Daniel H; Asfar, Pierre; Calzia, Enrico; Senftleben, Uwe; Gebhard, Florian; Georgieff, Michael; Radermacher, Peter; Hysa, Vladislava

    2011-04-01

    Inhaling hydrogen sulfide (H2S) reduced energy expenditure resulting in hypothermia. Because the inflammatory effects of either hypothermia alone or H2S per se still are a matter of debate, we tested the hypothesis whether inhaled H2S amplifies the hypothermia-related modulation of the inflammatory response. Fifteen hours after cecal ligation and puncture or sham laparotomy, anesthetized and mechanically ventilated normothermic and hypothermic mice (core temperature kept at 38°C and 27°C, respectively) received either 100 ppm H2S or vehicle. In the sham-operated animals, inhaled H2S and hypothermia alone comparably reduced the plasma chemokine and IL-6 levels, but combining hypothermia and inhaled H2S had no additional effect. The lung tissue cytokine and chemokine patterns revealed a similar response. During sepsis, inhaled H2S reduced the blood cytokine concentrations only, without effects on the plasma chemokine or the lung tissue levels. Again, inhaled H2S had no major additional effect during hypothermia. With or without sepsis, inhaled H2S and hypothermia alone comparably reduced the lung tissue heme oxygenase 1 expression, whereas inhaled H2S had no additional effect during hypothermia. Lung tissue nuclear transcription factor κB activation was reduced by combining H2S with hypothermia in the sham-operated animals, whereas it was increased by inhaled H2S during sepsis. Hypothermia amplified this response. Hence, during anesthesia and mechanical ventilation, inhaled H2S exerted anti-inflammatory effects, which were, however, not amplified by adding deliberate hypothermia. Sepsis attenuated these anti-inflammatory effects of inhaled H2S, which were at least in part independent of the nuclear transcription factor κB pathway.

  19. Effect of an imidazobenzodiazepine, Ro15-4513, on the incoordination and hypothermia produced by ethanol and pentobarbital

    SciTech Connect

    Hoffman, P.L.; Tabakoff, B.; Szabo, G.; Suzdak, P.D.; Paul, S.M.

    1987-08-03

    The imidazobenzodiazepine, Ro15-4513, which is a partial inverse agonist at brain benzodiazepine receptors, reversed the incoordinating effect of ethanol in mice, as measured on an accelerating Rotarod. This effect was blocked by benzodiazepine receptor antagonists. In contrast, Ro15-4513 had no effect on ethanol-induced hypothermia in mice. However, Ro15-4513 reversed the hypothermic effect of pentobarbital, and, at higher dose, also reversed the incoordinating effect of pentobarbital in mice. The data support the hypothesis that certain of the pharmacological effects of ethanol are mediated by actions at the GABA-benzodiazepine receptor-coupled chloride channel. 35 references, 2 figures.

  20. Extracranial hypothermia during cardiac arrest and cardiopulmonary resuscitation is neuroprotective in vivo.

    PubMed

    Hutchens, Michael P; Fujiyoshi, Tetsuhiro; Koerner, Ines P; Herson, Paco S

    2014-06-01

    There is increasing evidence that ischemic brain injury is modulated by peripheral signaling. Peripheral organ ischemia can induce brain inflammation and injury. We therefore hypothesized that brain injury sustained after cardiac arrest (CA) is influenced by peripheral organ ischemia and that peripheral organ protection can reduce brain injury after CA and cardiopulmonary resuscitation (CPR). Male C57Bl/6 mice were subjected to CA/CPR. Brain temperature was maintained at 37.5°C ± 0.0°C in all animals. Body temperature was maintained at 35.1°C ± 0.1°C (normothermia) or 28.8°C ± 1.5°C (extracranial hypothermia [ExHy]) during CA. Body temperature after resuscitation was maintained at 35°C in all animals. Behavioral testing was performed at 1, 3, 5, and 7 days after CA/CPR. Either 3 or 7 days after CA/CPR, blood was analyzed for serum urea nitrogen, creatinine, alanine aminotransferase, aspartate aminotransferase, and interleukin-1β; mice were euthanized; and brains were sectioned. CA/CPR caused peripheral organ and brain injury. ExHy animals experienced transient reduction in brain temperature after resuscitation (2.1°C ± 0.5°C for 4 minutes). Surprisingly, ExHy did not change peripheral organ damage. In contrast, hippocampal injury was reduced at 3 days after CA/CPR in ExHy animals (22.4% ± 6.2% vs. 45.7% ± 9.1%, p=0.04, n=15/group). This study has two main findings. Hypothermia limited to CA does not reduce peripheral organ injury. This unexpected finding suggests that after brief ischemia, such as during CA/CPR, signaling or events after reperfusion may be more injurious than those during the ischemic period. Second, peripheral organ hypothermia during CA reduces hippocampal injury independent of peripheral organ protection. While it is possible that this protection is due to subtle differences in brain temperature during early reperfusion, we speculate that additional mechanisms may be involved. Our findings add to the growing understanding of

  1. Pre-Treatment with Tyrosine Reverses Hypothermia Induced Behavioral Depression

    DTIC Science & Technology

    1989-09-01

    accelerated firing activates the enzyme tyrosine- hydroxylase , making it more tyrosine sensitive. The reduction of brain NA is accompanied by a behavioral...regions of the brain. The accelerated firing activates the enzyme tyrosine- hydroxylase , making it more tyrosine sensitive. The reduction of brain NA...depletion. The accelerated firing activates the enzyme tyrosine- hydroxylase (7), making it more tyrosine sensitive. It has been reported that

  2. Ca++ induced hypothermia in a hibernator /Citellus beechyi/

    NASA Technical Reports Server (NTRS)

    Hanegan, J. L.; Williams, B. A.

    1975-01-01

    Results of perfusion of excess Ca++ and Na+ into the hypothalamus of the hibernating ground squirrel Citellus beechyi are presented. The significant finding is that perfused excess Ca++ causes a reduction in core temperature when ambient temperature is low (12 C). Ca++ also causes a rise in rectal temperature at high ambient temperature (33 C). Thus hypothalamic Ca++ perfusion apparently causes a nonspecific depression of thermoregulatory control.

  3. The importance of cavity roosting and hypothermia to the energy balance of the winter acclimatized Carolina chickadee

    NASA Astrophysics Data System (ADS)

    Mayer, L.; Lustick, S.; Battersby, B.

    1982-09-01

    Noctural hypothermia and cavity roosting account for a significant reduction in energy expenditure in winter acclimatized Carolina chickadees. As much as 10‡C hypothermia amounted to a 33.0% reduction in metabolic requirements. Noctural hypothermia combined with a reduction in radiative and convective heat loss due to cavity roosting accounted for as much as a 50% savings in energy expenditure.

  4. Hypothermia-related deaths--Wisconsin, 2014, and United States, 2003-2013.

    PubMed

    Meiman, Jon; Anderson, Henry; Tomasallo, Carrie

    2015-02-20

    Hypothermia is defined as a core body temperature of <95°F (<35°C) and is caused by environmental exposure, drug intoxication, or metabolic or nervous system dysfunction. Exposure to cold is a leading cause of weather-related mortality and is responsible for approximately twice the number of deaths annually as exposure to heat in the United States. To understand the risk factors for hypothermia-related death and improve prevention efforts, during January 1-April 30, 2014, a period of record low temperatures, the Wisconsin Division of Public Health began active surveillance for hypothermia. Suspected hypothermia-related deaths were reported by coroners or medical examiners and identified in death records. Hypothermia was confirmed as the cause of death by review of death investigation narratives. This report describes three selected cases of hypothermia-related deaths in Wisconsin and summarizes characteristics of all cases that occurred in the state during the period of active surveillance. A summary of hypothermia-related deaths for the United States during 2003-2013 also is presented for comparison and to assess national mortality trends. Hypothermia continues to be an important cause of weather-related death. Key risk factors include drug intoxication, mental illness, and social isolation. State and local health agencies might need to focus outreach on vulnerable populations and target interventions for groups at highest risk for death.

  5. [Accidental hypothermia in adults: taking charge by the SAMU of Paris].

    PubMed

    Deny, N; Bresard, D; Bertrand, J; Poisvert, M

    1990-02-01

    Thirty one cases of accidental hypothermia have been taken in care by the SAMU de Paris during the year of 1987. The accidental hypothermias happening in the cities are, most of the time, moderated and not very serious. The search for a cause is a prime necessity. The prognosis is based on that search to guide and advise the patients.

  6. Platelet Function During Hypothermia in Experimental Mock Circulation.

    PubMed

    Van Poucke, Sven; Stevens, Kris; Kicken, Cécile; Simons, Antoine; Marcus, Abraham; Lancé, Marcus

    2016-03-01

    Alterations in platelet function are a common finding in surgical procedures involving cardiopulmonary bypass and hypothermia. Although the combined impact of hypothermia and artificial circulation on platelets has been studied before, the ultimate strategy to safely minimize the risk for bleeding and thrombosis is yet unknown. The aim of this study was to evaluate the use of a mock circulation loop to study the impact of hypothermia for platelet-related hemostatic changes. Venous blood was collected from healthy adult humans (n = 3). Closed mock circulation loops were assembled, each consisting of a centrifugal pump, an oxygenator with integrated heat exchanger, and a hardshell venous reservoir. The experiment started with the mock circulation temperature set at 37°C (T0 [0 h]). Cooling was then initiated at T1 (+2 h), where temperature was adjusted from 37°C to 32°C. Hypothermia was maintained from T2 (+4 h) to T3 (+28 h). From that point in time, rewarming from 32°C to 37°C was initiated with similar speed as cooling. From time point T4 (+30 h), normothermia (37°C) was maintained until the experiment ended at T5 (+32 h). Blood samples were analyzed in standard hematological tests: light transmission aggregometry (LTA) (arachidonic acid [AA], adenosine diphosphate [ADP], collagen [COL], thrombin-receptor-activating-peptide-14 [TRAP]), multiple electrode aggregometry (MEA) (AA, ADP, COL, TRAP), and rotational thromboelastometry (ROTEM) (EXTEM, FIBTEM, PLTEM). Hemoglobin, hematocrit, and platelet count decrease more substantially during temperature drop (37-32°C) than during hypothermia maintenance. Hb and Hct continue to follow this trend during active rewarming (32-37°C). PC increase from the moment active rewarming was initiated. None of the values return to the initial values. LTA values demonstrate a similar decrease in aggregation after stimulation with the platelet agonists between the start of the mock circulation and the start of cooling. Except

  7. Death from Hypothermia during a Training Course under "Extreme Conditions": Related to Two Cases.

    PubMed

    Perich, Pierre; Tuchtan, Lucile; Bartoli, Christophe; Léonetti, Georges; Piercecchi-Marti, Marie-Dominique

    2016-03-01

    Death from hypothermia following exhaustion or from various complicated pathologies is no longer a frequent cause of death among combat troops. During a training course under "extreme conditions" in the French Alps, two young African officers died. Confronted with these two clinically confirmed cases of hypothermia, the unknown anatomopathological and biological specificities associated with death from hypothermia were highlighted. In these typical and clinically confirmed cases of death from subacute exhaustion hypothermia, none of the signs revealed by the autopsy were specific. Although some recent publications have addressed the utility of postmortem biochemical markers when establishing a diagnosis, with no anamnesis, with no knowledge or analysis of the circumstances of death, and without an in situ examination of the body, it appears difficult, if not impossible, to confirm that death was caused by hypothermia.

  8. Diagnostic performance of urinary metanephrines for the postmortem diagnosis of hypothermia.

    PubMed

    Palmiere, Cristian; Teresiński, Grzegorz; Hejna, Petr; Mangin, Patrice; Grouzmann, Eric

    2014-12-01

    The purpose of this study was to assess the diagnostic potential of urinary metanephrines and 3-methoxytyramine compared to urinary catecholamine determination in diagnosing antemortem cold exposure and fatal hypothermia. 83 cases of fatal hypothermia and 144 control cases were included in this study. Catecholamines (adrenaline, noradrenaline and dopamine), metanephrines (metanephrine, normetanephrine) and 3-methoxytyramine were measured in urine collected during autopsy. All tested analytes were significantly higher in hypothermia cases compared to control subjects and displayed a generally satisfying discriminative value, thus indicating urinary catecholamines and their metabolites as reliable markers of cold-related stress and hypothermia related-deaths. Metanephrine and adrenaline had the best discriminative value between hypothermia and control cases compared to other tested analytes, though with different sensitivity and specificity. These can therefore be considered the most suitable markers of cold-related stress.

  9. Retrospective study of the prevalence of postanaesthetic hypothermia in dogs.

    PubMed

    Redondo, J I; Suesta, P; Serra, I; Soler, C; Soler, G; Gil, L; Gómez-Villamandos, R J

    2012-10-13

    The anaesthetic records of 1525 dogs were examined to determine the prevalence of postanaesthetic hypothermia, its clinical predictors and consequences. Temperature was recorded throughout the anaesthesia. At the end of the procedure, details coded in were: hyperthermia (>39.50°C), normothermia (38.50°C-39.50°C), slight (38.49°C-36.50°C), moderate (36.49°C-34.00°C) and severe hypothermia (<34.00°C). Statistical analysis consisted of multiple regression to identify the factors that are associated with the temperature at the end of the procedure. Before premedication, the temperature was 38.7 ± 0.6°C (mean ± sd). At 60, 120 and 180 minutes from induction, the temperature was 36.7 ± 1.3°C, 36.1 ± 1.4°C and 35.8 ± 1.5°C, respectively. The prevalence of hypothermia was: slight, 51.5 per cent (95 per cent CI 49.0 to 54.0 per cent); moderate, 29.3 per cent (27.1-31.7 per cent) and severe: 2.8% (2.0-3.7%). The variables that associated with a decrease in the temperature recorded at the end of the anaesthesia were: duration of the preanesthetic time, duration of the anaesthesia, physical condition (ASA III and ASA IV dogs showed lower temperatures than ASA I dogs), the reason for anaesthesia (anaesthesia for diagnostic procedures or thoracic surgery reduce the temperature when compared with minor procedures), and the recumbency during the procedure (sternal and dorsal recumbencies showed lower temperatures than lateral recumbency). The temperature before premedication and the body surface (BS) were associated with a higher temperature at the end of the anaesthesia, and would be considered as protective factors.

  10. Requirements for Information/Education Programs on Hypothermia.

    DTIC Science & Technology

    1979-10-23

    AO-A083 716 CLEMSON UNIV SC F/B 13/10 REQUIREMENTS FOR INFORMATION/EDUCATION PROGRAMS ON HYPOTHERMIA.(U) 0 16 OCT 79 M C PRIDGEN, R M HARNETT DOT-CG...34t!Fu I. No. 4TRAIS) ystems EngJ-e-Ing Program Clemson University DTC-27- Memson, S. C. 29631 12. T1-. afNeee .d P7id ... 1.SosrnAgnc eand Address...was performed at Clemson University under the auspices of the U.S. Coast Guard with LTJg Steven F. Wlker and Ens. John A. Budde serving as program

  11. [Knowledge of hypothermia in nursing professionals of surgical center].

    PubMed

    Mendoza, Isabel Yovana Quispe; Peniche, Aparecida de Cássia Giani; Püschel, Vilanice Alves de Araujo

    2012-10-01

    The objective was to identify the difference in knowledge about hypothermia in nursing assistant after an educational intervention. The conceptual basis of education is based on the prospect of meaningful learning allied to the construction of the conceptual map and the case study. Data were collected through the questionnaire validated by experts. The average knowledge after the educational intervention was (-3.49), however, there was no significant difference in knowledge as related to sociodemographic variables studied. We conclude that the educational intervention was satisfactory in that new information was anchored modified and expanded the cognitive structure of study subjects.

  12. A recirculating cooling system for improved topical cardiac hypothermia.

    PubMed

    Rosenfeldt, F L; Fambiatos, A; Pastoriza-Pinol, J; Stirling, G R

    1981-10-01

    A simple system is described that recirculates cooling fluid for topical cardiac hypothermia. This disposable system can produce a flow of 1,500 ml/min at 2 degrees to 4 degrees C. The recirculating cooler produced significantly lower myocardial temperatures than a conventional fluid-discard system in 22 patients having coronary operation. This system has been used as part of the technique of hypothermic cardioplegia in more than 600 patients. During various cardiac procedures, septal temperatures were maintained well below 20 degrees C for 60 minutes or more without the need to reinfuse the cardioplegic solution.

  13. Data on pharmacological applications and hypothermia protection against in vitro oxygen-glucose-deprivation-related neurodegeneration of adult rat CA1 region.

    PubMed

    Öz, Pınar; Saybaşılı, Hale

    2017-02-01

    In this data article, the level of chemical neuroprotection against oxygen-glucose-deprivation (OGD)-related neurodegeneration in CA1 was analyzed using the measurements on CA1 stratum pyramidale (CA1sp) width. Adult rat hippocampal slices were incubated in OGD medium for 60 min to create a model for severe ischemic conditions. Alternatively, control slices were incubated in artificial cerebrospinal fluid (ACSF) for 60 min. A study of OGD induced neurodegeneration and partial prevention by pharmacological agents reported; baclofen, memantine and l-carnitine effects were included. Also, the use of hypothermia was reported (P. Öz, H. Saybaşılı, 2016) [1]. Here, the use CA1sp width measurements on Nissl-stained hippocampal slices is introduced as a valid and affordable method for detecting the level of neurodegeneration and neuroprotection on hippocampal slices. The protective effect of hypothermia was found to be more pronounced compared to other agents.

  14. Limitations of Mild, Moderate, and Profound Hypothermia in Protecting Developing Hippocampal Neurons After Simulated Ischemia.

    PubMed

    Gregersen, Maren; Lee, Deok Hee; Gabatto, Pablo; Bickler, Philip E

    2013-12-01

    Mild hypothermia (33°C-34°C) after cerebral ischemia in intact animals or ischemia-like conditions in vitro reduces neuron death. However, it is now clear that more profound hypothermia or delayed hypothermia may not provide significant protection. To further define the limitations of hypothermia after cerebral ischemia, we used hippocampal slice cultures to examine the effects of various degrees, durations, and delays of hypothermia on neuron death after an ischemia-like insult. Organotypic cultures of the hippocampus from 7- to 8 day-old rat pups were cooled to 32°C, 23°C, 17°C, or 4°C immediately or after a 2-4 hour delay from an injurious insult of oxygen and glucose deprivation (OGD). Cell death in CA1, CA3 and dentate regions of the cultures was assessed 24 hours later with SYTOX(®) or propidium iodide, both of which are fluorescent markers labeling damaged cells. OGD caused extensive cell death in CA1, CA3, and dentate regions of the hippocampal cultures. Hypothermia (32°C, 23°C and 17°C) for 4-6 hours immediately after OGD was protective at 24 hours, but when hypothermia was applied for longer periods or delayed after OGD, no protection or increased death was seen. Ultra-profound hypothermia (4°C) increased cell death in all cell areas of the hippocampus even when after a milder insult of only hypoxia. In an in vitro model of recovery after an ischemia-like insult, mild to profound hypothermia is protective only when applied without delay and for limited periods of time (6-8 hours). Longer durations of hypothermia, or delayed application of the hypothermia can increase neuron death. These findings may have implications for clinical uses of therapeutic hypothermia after hypoxic or ischemic insults, and suggest that further work is needed to elucidate the limitations of hypothermia as a protective treatment after ischemic stress.

  15. Combination of mild hypothermia with neuroprotectants has greater neuroprotective effects during oxygen-glucose deprivation and reoxygenation-mediated neuronal injury.

    PubMed

    Gao, Xiao-Ya; Huang, Jian-Ou; Hu, Ya-Fang; Gu, Yong; Zhu, Shu-Zhen; Huang, Kai-Bin; Chen, Jin-Yu; Pan, Su-Yue

    2014-11-18

    Co-treatment of neuroprotective reagents may improve the therapeutic efficacy of hypothermia in protecting neurons during ischemic stroke. This study aimed to find promising drugs that enhance the neuroprotective effect of mild hypothermia (MH). 26 candidate drugs were selected based on different targets. Primary cultured cortical neurons were exposed to oxygen-glucose deprivation and reoxygenation (OGD/R) to induce neuronal damage, followed by either single treatment (a drug or MH) or a combination of a drug and MH. Results showed that, compared with single treatment, combination of MH with brain derived neurotrophic factor, glibenclamide, dizocilpine, human urinary kallidinogenase or neuroglobin displayed higher proportion of neuronal cell viability. The latter three drugs also caused less apoptosis rate in combined treatment. Furthermore, co-treatment of those three drugs and MH decreased the level of reactive oxygen species (ROS) and intracellular calcium accumulation, as well as stabilized mitochondrial membrane potential (MMP), indicating the combined neuroprotective effects are probably via inhibiting mitochondrial apoptosis pathway. Taken together, the study suggests that combined treatment with hypothermia and certain neuroprotective reagents provide a better protection against OGD/R-induced neuronal injury.

  16. Combination of mild hypothermia with neuroprotectants has greater neuroprotective effects during oxygen-glucose deprivation and reoxygenation-mediated neuronal injury

    PubMed Central

    Gao, Xiao-Ya; Huang, Jian-Ou; Hu, Ya-Fang; Gu, Yong; Zhu, Shu-Zhen; Huang, Kai-Bin; Chen, Jin-Yu; Pan, Su-Yue

    2014-01-01

    Co-treatment of neuroprotective reagents may improve the therapeutic efficacy of hypothermia in protecting neurons during ischemic stroke. This study aimed to find promising drugs that enhance the neuroprotective effect of mild hypothermia (MH). 26 candidate drugs were selected based on different targets. Primary cultured cortical neurons were exposed to oxygen-glucose deprivation and reoxygenation (OGD/R) to induce neuronal damage, followed by either single treatment (a drug or MH) or a combination of a drug and MH. Results showed that, compared with single treatment, combination of MH with brain derived neurotrophic factor, glibenclamide, dizocilpine, human urinary kallidinogenase or neuroglobin displayed higher proportion of neuronal cell viability. The latter three drugs also caused less apoptosis rate in combined treatment. Furthermore, co-treatment of those three drugs and MH decreased the level of reactive oxygen species (ROS) and intracellular calcium accumulation, as well as stabilized mitochondrial membrane potential (MMP), indicating the combined neuroprotective effects are probably via inhibiting mitochondrial apoptosis pathway. Taken together, the study suggests that combined treatment with hypothermia and certain neuroprotective reagents provide a better protection against OGD/R-induced neuronal injury. PMID:25404538

  17. Treatment of hypothermia in trauma victims: thermodynamic considerations.

    PubMed

    Gentilello, L M; Moujaes, S

    1995-01-01

    The relatively high specific heat of the human body makes hypothermia very difficult to treat. Although there are many treatment methods available, most evaluations of rewarming techniques are based on clinically observed rewarming rates, and they do not take into account initial core temperature, ambient temperature, the patient's own heat production, the effects of anesthesia, paralytic agents, and other variables. A heat transfer model is proposed that simulates the flow of heat through the body of a hypothermic patient. The model uses first principles involved in heat transfer and thermodynamics to describe the effects of currently available rewarming techniques. A commercially available routine is used to solve the equations, which also include any heat exchange between the patient's body and the environment, as well as metabolic heat generation as a function of time and core temperature. This thermodynamic analysis of rewarming, based on computer modeling of heat transfer, provides a scientific basis on which to establish guidelines for appropriate selection of treatment strategies for hypothermia, and it indicates that direct blood warming or infusion of warm intravenous fluids are the most effective rewarming techniques.

  18. Acoustothermometric study of the human hand under hyperthrmia and hypothermia

    NASA Astrophysics Data System (ADS)

    Anosov, A. A.; Belyaev, R. V.; Vilkov, V. A.; Dvornikova, M. V.; Dvornikova, V. V.; Kazanskii, A. S.; Kuryatnikova, N. A.; Mansfel'd, A. D.

    2013-01-01

    The results of an acoustothermometric study of the human hand under local hyperthermia and hypothermia are presented. Individuals under testing plunged their hands in hot or cold water for several minutes. Thermal acoustic radiation was detected by two sensors placed near the palm and near the backside of the tested hand. The internal temperature profiles of the hand were reconstructed. The indirect estimate of the reconstruction error was 0.6°C, which is acceptable for medical applications. Hyperthermia was achieved by placing the hand in water with a maximal temperature of 44°C for 2 min. In this case, the internal temperature was 35.4 ± 0.6°C. Hypothermia was achieved by placing the hand in water with a temperature of 17.8°C for 15 min. In this case, the internal temperature decreased from 26 to 24°C. The use of a four-sensor planar receiving array allowed dynamic mapping of the acoustic brightness temperature of the hand.

  19. 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.

  20. Infrared fibers for radiometer thermometry in hypothermia and hyperthermia treatment

    SciTech Connect

    Katzir, A.; Bowman, H.F.; Asfour, Y.; Zur, A.; Valeri, C.R.

    1989-06-01

    Hypothermia is a condition which results from prolonged exposure to a cold environment. Rapid and efficient heating is needed to rewarm the patient from 32-35 degrees C to normal body temperature. Hyperthermia in cancer treatment involves heating malignant tumors to 42.5-43.0 degrees C for an extended period (e.g., 30 min) in an attempt to obtain remission. Microwave or radio frequency heating is often used for rewarming in hypothermia or for temperature elevation in hyperthermia treatment. One severe problem with such heating is the accurate measurement and control of temperature in the presence of a strong electromagnetic field. For this purpose, we have developed a fiberoptic radiometer system which is based on a nonmetallic, infrared fiber probe, which can operate either in contact or noncontact mode. In preliminary investigations, the radiometer worked well in a strong microwave or radiofrequency field, with an accuracy of +/- 0.5 degrees C. This fiberoptic thermometer was used to control the surface temperature of objects within +/- 2 degrees C.

  1. The effect of hypothermia on the expression of neurotrophin mRNA in the hippocampus following transient cerebral ischemia in the rat.

    PubMed

    Boris-Möller, F; Kamme, F; Wieloch, T

    1998-12-10

    The expression of the mRNAs of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT3) and the neurotrophin receptor, TrkB, was studied in the rat hippocampus by in situ hybridization following normothermic (37 degreesC) and protective hypothermic (33 degreesC) transient cerebral ischemia of 15 min duration. In the resistant dentate gyrus, normothermic ischemia transiently induced NGF mRNA at around 8 h of recovery, while the NT3 mRNA levels were depressed over at least a 24-h recovery period. The levels of BDNF and TrkB were transiently and markedly elevated with a maximal expression at 24 h of recovery. Intraischemic hypothermia reduced the induction of NGF mRNA, while the increase of BDNF mRNA expression occurred earlier during recovery, and the post-ischemic NT3 mRNA depression was not affected. Also, the expression of TrkB mRNA was enhanced, and occurred concomitantly with the elevation of BDNF mRNA. In contrast, there were no changes in neurotrophin and TrkB mRNA in the CA3 and CA1 regions. The expression of BDNF mRNA at 24 h after normothermic ischemia, was attenuated by intraischemic hypothermia. We conclude that, the expressions of NGF, BDNF, NT3 or TrkB mRNA in ischemia-sensitive hippocampal subregions are not increased by protective hypothermia. In contrast, hypothermia induces neurotrophin mRNA alterations in the ischemia-resistant dentate gyrus that may convey protection to sensitive regions.

  2. The effect of therapeutic hypothermia on drug metabolism and drug response: cellular mechanisms to organ function

    PubMed Central

    Zhou, Jiangquan; Poloyac, Samuel M.

    2011-01-01

    Introduction Therapeutic hypothermia is being employed, clinically based, on its neuro-protective benefits. Both critical illness and therapeutic hypothermia significantly affect drug disposition, potentially contributing to drug-therapy and drug-disease interaction. Currently, there is limited written information of the known alterations in drug concentration and response during mild hypothermia treatment and there is a limited understanding of the specific mechanisms that underlie alterations in drug concentrations and the potential clinical importance of these changes. Areas covered A systemic review of the effect of therapeutic hypothermia on drug metabolism, disposition, and response is provided. Specifically, the clinical and preclinical evidence of the effects of therapeutic hypothermia on blood flow, specific hepatic metabolism pathways, transporter, renal excretion, pharmacodynamics and rewarming effect are reviewed. Expert Opinion Available evidence demonstrates that mild hypothermia decreases the clearance of a variety of drugs with apparently little change in drug protein binding. Recent evidence suggests that the magnitude of the change is elimination route specific. Further research is needed to determine the impact of these alterations on both drug concentration and response in order to optimize the hypothermia therapy in this vulnerable patient population. PMID:21473710

  3. Involvement of prostaglandins and histamine in radiation-induced temperature responses in rats

    SciTech Connect

    Kandasamy, S.B.; Hunt, W.A. )

    1990-01-01

    Exposure of rats to 1-15 Gy of gamma radiation induced hyperthermia, whereas exposure to 20-150 Gy produced hypothermia. Since radiation exposure induced the release of prostaglandins (PGs) and histamine, the role of PGs and histamine in radiation-induced temperature changes was examined. Radiation-induced hyper- and hypothermia were antagonized by pretreatment with indomethacin, a cyclooxygenase inhibitor. Intracerebroventricular administration of PGE2 and PGD2 induced hyper- and hypothermia, respectively. Administration of SC-19220, a specific PGE2 antagonist, attenuated PGE2- and radiation-induced hyperthermia, but it did not antagonize PGD2- or radiation-induced hypothermia. Consistent with an apparent role of histamine in hypothermia, administration of disodium cromoglycate (a mast cell stabilizer), mepyramine (H1-receptor antagonist), or cimetidine (H2-receptor antagonist) attenuated PGD2- and radiation-induced hypothermia. These results suggest that radiation-induced hyperthermia is mediated via PGE2 and that radiation-induced hypothermia is mediated by another PG, possibly PGD2, via histamine.

  4. Practicability of avoiding hypothermia in resuscitation room phase in severely injured patients.

    PubMed

    Jensen, K O; Jensen, J M; Sprengel, K

    2015-05-01

    Hypothermia in severely injured patients is a high demanding situation resulting from an effect of injury severity, surrounding temperature at trauma site and admittance. This article reviews the possible options to combat hypothermia in the resuscitation room with respect to practicability. This review summarizes available passive and active re-warming techniques and trys to offer a practicable chronology to restore normothermia. Resources should be applied depending on the availability of each institution and manifestation of hypothermia, but there is a strong demand for improvements with respect to practicability, convenience and safety for the patient.

  5. Induction of therapeutic hypothermia by pharmacological modulation of temperature-sensitive TRP channels: theoretical framework and practical considerations.

    PubMed

    Feketa, Viktor V; Marrelli, Sean P

    2015-01-01

    Therapeutic hypothermia has emerged as a remarkably effective method of neuroprotection from ischemia and is being increasingly used in clinics. Accordingly, it is also a subject of considerable attention from a basic scientific research perspective. One of the fundamental problems, with which current studies are concerned, is the optimal method of inducing hypothermia. This review seeks to provide a broad theoretical framework for approaching this problem, and to discuss how a novel promising strategy of pharmacological modulation of the thermosensitive ion channels fits into this framework. Various physical, anatomical, physiological and molecular aspects of thermoregulation, which provide the foundation for this text, have been comprehensively reviewed and will not be discussed exhaustively here. Instead, the first part of the current review, which may be helpful for a broader readership outside of thermoregulation research, will build on this existing knowledge to outline possible opportunities and research directions aimed at controlling body temperature. The second part, aimed at a more specialist audience, will highlight the conceptual advantages and practical limitations of novel molecular agents targeting thermosensitive Transient Receptor Potential (TRP) channels in achieving this goal. Two particularly promising members of this channel family, namely TRP melastatin 8 (TRPM8) and TRP vanilloid 1 (TRPV1), will be discussed in greater detail.

  6. Insomnia Caused by Serotonin Depletion is Due to Hypothermia

    PubMed Central

    Murray, Nicholas M.; Buchanan, Gordon F.; Richerson, George B.

    2015-01-01

    Study Objective: Serotonin (5-hydroxytryptamine, 5-HT) neurons are now thought to promote wakefulness. Early experiments using the tryptophan hydroxylase inhibitor para-chlorophenylalanine (PCPA) had led to the opposite conclusion, that 5-HT causes sleep, but those studies were subsequently contradicted by electrophysiological and behavioral data. Here we tested the hypothesis that the difference in conclusions was due to failure of early PCPA experiments to control for the recently recognized role of 5-HT in thermoregulation. Design: Adult male C57BL/6N mice were treated with PCPA (800 mg/kg intraperitoneally for 5 d; n = 15) or saline (n = 15), and housed at 20°C (normal room temperature) or at 33°C (thermoneutral for mice) for 24 h. In a separate set of experiments, mice were exposed to 4°C for 4 h to characterize their ability to thermoregulate. Measurements and Results: PCPA treatment reduced brain 5-HT to less than 12% of that of controls. PCPA-treated mice housed at 20°C spent significantly more time awake than controls. However, core body temperature decreased from 36.5°C to 35.1°C. When housed at 33°C, body temperature remained normal, and total sleep duration, sleep architecture, and time in each vigilance state were the same as controls. When challenged with 4°C, PCPA-treated mice experienced a precipitous drop in body temperature, whereas control mice maintained a normal body temperature. Conclusions: These results indicate that early experiments using para-chlorophenylalanine that led to the conclusion that 5-hydroxytryptamine (5-HT) causes sleep were likely confounded by hypothermia. Temperature controls should be considered in experiments using 5-HT depletion. Citation: Murray NM, Buchanan GF, Richerson GB. Insomnia caused by serotonin depletion is due to hypothermia. SLEEP 2015;38(12):1985–1993. PMID:26194567

  7. Angiogenesis Dysregulation in Term Asphyxiated Newborns Treated with Hypothermia

    PubMed Central

    Shaikh, Henna; Boudes, Elodie; Khoja, Zehra; Shevell, Michael; Wintermark, Pia

    2015-01-01

    Background Neonatal encephalopathy following birth asphyxia is a major predictor of long-term neurological impairment. Therapeutic hypothermia is currently the standard of care to prevent brain injury in asphyxiated newborns but is not protective in all cases. More robust and versatile treatment options are needed. Angiogenesis is a demonstrated therapeutic target in adult stroke. However, no systematic study examines the expression of angiogenesis-related markers following birth asphyxia in human newborns. Objective This study aimed to evaluate the expression of angiogenesis-related protein markers in asphyxiated newborns developing and not developing brain injury compared to healthy control newborns. Design/Methods Twelve asphyxiated newborns treated with hypothermia were prospectively enrolled; six developed eventual brain injury and six did not. Four healthy control newborns were also included. We used Rules-Based Medicine multi-analyte profiling and protein array technologies to study the plasma concentration of 49 angiogenesis-related proteins. Mean protein concentrations were compared between each group of newborns. Results Compared to healthy newborns, asphyxiated newborns not developing brain injury showed up-regulation of pro-angiogenic proteins, including fatty acid binding protein-4, glucose-6-phosphate isomerase, neuropilin-1, and receptor tyrosine-protein kinase erbB-3; this up-regulation was not evident in asphyxiated newborns eventually developing brain injury. Also, asphyxiated newborns developing brain injury showed a decreased expression of anti-angiogenic proteins, including insulin-growth factor binding proteins -1, -4, and -6, compared to healthy newborns. Conclusions These findings suggest that angiogenesis pathways are dysregulated following birth asphyxia and are putatively involved in brain injury pathology and recovery. PMID:25996847

  8. Heat and cold acclimation in helium-cold hypothermia in the hamster.

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.

    1972-01-01

    A study was made of the effects of acclimation of hamsters to high (34-35 C) and low (4-5 C) temperatures for periods up to 6 weeks on the induction of hypothermia in hamsters. Hypothermia was achieved by exposing hamsters to a helox mixture of 80% helium and 20% oxygen at 0 C. Hypothermic induction was most rapid (2-3 hr) in heat-acclimated hamsters and slowest (6-12 hr) in cold-acclimated hamsters. The induction period was intermediate (5-8 hr) in room temperature nonacclimated animals (controls). Survival time in hypothermia was relatable to previous temperature acclimations. The hypothesis that thermogenesis in cold-acclimated hamsters would accentuate resistance to induction of hypothermia was substantiated.

  9. Pre-hospital core temperature measurement in accidental and therapeutic hypothermia.

    PubMed

    Strapazzon, Giacomo; Procter, Emily; Paal, Peter; Brugger, Hermann

    2014-06-01

    Core temperature (T core) measurement is the only diagnostic tool to accurately assess the severity of hypothermia. International recommendations for management of accidental hypothermia encourage T core measurement for triage, treatment, and transport decisions, but they also recognize that lack of equipment may be a limiting factor, particularly in the field. The aim of this nonsystematic review is to highlight the importance of field measurement of T core and to provide practical guidance for clinicians on pre-hospital temperature measurement in accidental and therapeutic hypothermia. Clinicians should recognize the difference between alternative measurement locations and available thermometers, tailoring their decision to the purpose of the measurement (i.e., intermittent vs. continual measurement), and the impact on management decisions. The importance of T core measurement in therapeutic hypothermia protocols during early cooling and monitoring of target temperature is discussed.

  10. Liquid crystal thermometry for the detection of neonatal hypothermia in Nepal.

    PubMed

    Manandhar, N; Ellis, M; Manandhar, D S; Morley, D; de L Costello, A M

    1998-02-01

    We assessed the sensitivity, specificity and likelihood ratio of a low cost liquid crystal strip thermometer (LCT) compared with axillary mercury thermometry for the detection of neonatal hypothermia in Nepal. The subjects were 76 healthy newborns in the government maternity hospital of Kathmandu, Nepal in winter. The validity of LCT for the detection of neonatal hypothermia (less than 36 degrees C) showed a sensitivity of 83 per cent, specificity 96 per cent, positive predictive value 98 per cent and a likelihood ratio of 23. Use of LCT on newborns in this setting raises a measured pretest probability of first day hypothermia of 63 per cent to a post-test probability of 97 per cent. Liquid crystal thermometry is a simple, low-cost, and valid method for identifying core hypothermia in newborns. It is ideal for isolated rural communities where LCT strips could be added to delivery kits.

  11. Outcome After Therapeutic Hypothermia in Term Neonates with Encephalopathy and a Syndromic Diagnosis

    PubMed Central

    Mrelashvili, Anna; Bonifacio, Sonia L.; Rogers, Elizabeth E.; Shimotake, Thomas K.; Glass, Hannah C.

    2015-01-01

    The large randomized, controlled trials of therapeutic hypothermia for hypoxic-ischemic encephalopathy (HIE) excluded neonates with congenital disorders. The objective of this study was to report our experience using hypothermia in neonates with signs of HIE and a syndromic disorder or brain anomaly. Subjects were identified from a database of neonates admitted to the Neuro-Intensive Care Nursery at University of California, San Francisco. Of 169 patients fulfilling criteria for hypothermia, eight (5%) had a syndromic disorder, and were cooled as per guidelines for non-syndromic neonates. Perinatal characteristics of infants with and without syndromic disorder were not significantly different. Overall outcome was poor: 38% had evidence of acute HI injury, 3 subjects died, two survivors had low developmental quotient (DQ 25). The risk versus benefit of therapeutic hypothermia for HIE among neonates with congenital brain malformations or syndromic diagnoses is uncertain. PMID:25762585

  12. Mild Hypothermia May Offer Some Improvement to Patients with MODS after CPB Surgery

    PubMed Central

    Zhao, Xiaoqi; Gu, Tianxiang; Xiu, Zongyi; Shi, Enyi; Yu, Lei

    2016-01-01

    OBJECTIVE: To summarize the effect of mild hypothermia on function of the organs in patients with multiple organ dysfunction syndrome after cardiopulmonary bypass surgery. METHODS: The patients were randomly divided into two groups, northermia group (n=71) and hypothermia group (n=89). We immediately began cooling the hypothermia group when test results showed multiple organ dysfunction syndrome, meanwhile all patients of two groups were drawn blood to test blood gas, liver and kidney function, blood coagulation function, and evaluated the cardiac function using echocardiography from 12 to 36 hours. We compared the difference of intra-aortic balloon pump, extracorporeal membrane oxygenation rate and mortality within one month after intensive care unit admission. RESULTS: Among the 160 patients, 36 died, 10 (11.24%) patients were from the hypothermia group and 26 (36.6%) from the northermia group (P <0.05). In northermia group, 45 (63.38%) patients used intra-aortic balloon pump and 4 (5.63%), extracorporeal membrane oxygenation; in hypothermia group, 35 (39.32%) patients used intra-aortic balloon pump and 2 (2.25%), extracorporeal membrane oxygenation( P <0.05). The patients' heart rate decreased significantly in the hypothermia group. The heart rate of hypothermia group is significantly slower than the northermia group at the 36th hour (P <0.05). But the mean arterial pressure of hypothermia group is significantly higher than the northermia group at the 36th hour (P <0.05). In hypothermia group, PO2, SvO2 and lactate were improved significantly compared to pre-cooling (P <0.05), and they were significantly better than the northermia group at the 36th hour (P <0.05%). Prothrombin time and activated partial thromboplastin time have no significantly difference between the two groups (P >0.05). But the platelet count has significantly difference between the two groups at the 36th hour (P <0.05). The aspartate transaminase, alanine transaminase and creatinine were

  13. Induction of Cu,Zn-superoxide dismutase after cortical contusion injury during hypothermia.

    PubMed

    Fukuhara, T; Nishio, S; Ono, Y; Kawauchi, M; Asari, S; Ohmoto, T

    1994-09-19

    To determine the effect of hypothermia on superoxide injury after cerebral contusion, the induction of Cu,Zn-superoxide dismutase was examined 6 h after contusion in rats using Northern blotting. Cu,Zn-superoxide dismutase gene expression increased at the periphery of the contusion, which may indicate the severity of the superoxide stimulus. This increase was preserved after contusion under hypothermia, which may show that superoxide injury is still severe although brain edema is decreased.

  14. Hypothermia reduces VEGF-165 expression, but not osteogenic differentiation of human adipose stem cells under hypoxia

    PubMed Central

    Bakker, Astrid D.; Hogervorst, Jolanda M. A.; Nolte, Peter A.; Klein-Nulend, Jenneke

    2017-01-01

    Cryotherapy is successfully used in the clinic to reduce pain and inflammation after musculoskeletal damage, and might prevent secondary tissue damage under the prevalent hypoxic conditions. Whether cryotherapy reduces mesenchymal stem cell (MSC) number and differentiation under hypoxic conditions, causing impaired callus formation is unknown. We aimed to determine whether hypothermia modulates proliferation, apoptosis, nitric oxide production, VEGF gene and protein expression, and osteogenic/chondrogenic differentiation of human MSCs under hypoxia. Human adipose MSCs were cultured under hypoxia (37°C, 1% O2), hypothermia and hypoxia (30°C, 1% O2), or control conditions (37°C, 20% O2). Total DNA, protein, nitric oxide production, alkaline phosphatase activity, gene expression, and VEGF protein concentration were measured up to day 8. Hypoxia enhanced KI67 expression at day 4. The combination of hypothermia and hypoxia further enhanced KI67 gene expression compared to hypoxia alone, but was unable to prevent the 1.2-fold reduction in DNA amount caused by hypoxia at day 4. Addition of hypothermia to hypoxic cells did not alter the effect of hypoxia alone on BAX-to-BCL-2 ratio, alkaline phosphatase activity, gene expression of SOX9, COL1, or osteocalcin, or nitric oxide production. Hypothermia decreased the stimulating effect of hypoxia on VEGF-165 gene expression by 6-fold at day 4 and by 2-fold at day 8. Hypothermia also decreased VEGF protein expression under hypoxia by 2.9-fold at day 8. In conclusion, hypothermia decreased VEGF-165 gene and protein expression, but did not affect differentiation, or apoptosis of MSCs cultured under hypoxia. These in vitro results implicate that hypothermia treatment in vivo, applied to alleviate pain and inflammation, is not likely to harm early stages of callus formation. PMID:28166273

  15. An Evaluation of Human Thermal Models for the Study of Immersion Hypothermia Protection Equipment

    DTIC Science & Technology

    1979-10-12

    in a cold environment. The models are evaluated for their ability to predict the effecltve- ness of anti-exposure equipment used during rold water ...with modified and experimental submodels are -• d iscussed . .... .t t 17. Koey Words - 1. Oitrti~n Stetemet immersion hypothermia, hypothermia, Document...affected modtels and In some cases were necessary In order to give the modelc any chance of performing as required for the evaluation of cold water

  16. SU-C-213-07: Fabrication and Testing of a 3D-Printed Small Animal Rectal Cooling Device to Evaluate Local Hypothermia as a Radioprotector During Prostate SBRT

    SciTech Connect

    Hrycushko, B; Chopra, R; Futch, C; Bing, C; Wodzak, M; Stojadinovic, S; Jiang, S; Medin, P

    2015-06-15

    Purpose: The protective effects of induced or even accidental hypothermia on the human body are widespread with several medical uses currently under active research. In vitro experiments using human cell lines have shown hypothermia provides a radioprotective effect that becomes more pronounced at large, single-fraction doses common to SBRT treatments. Relevant to prostate SBRT, this work details the fabrication and testing of a 3D-printed cooling device to facilitate the investigation of the radioprotective effect of local hypothermia on the rat rectum. Methods: A 3cm long, two-channel rectal cooling device was designed in SOLIDWORKS CAD for 3D printing. The water intake nozzle is connected to a 1mm diameter brass pipe from which water flows and circulates back around to the exit nozzle. Both nozzles are connected by plastic tubing to a water chiller pump. Following leak-proof testing, fiber optic temperature probes were used to evaluate the temperature over time when placed adjacent to the cooling device within a rat rectum. MRI thermometry characterized the relative temperature distribution in concentric ROIs surrounding the probe. CBCT images from a small-animal irradiator were evaluated for imaging artifacts which could affect Monte Carlo dose calculations during treatment planning. Results: The rectal temperature adjacent to the cooling device decreased from body temperature (37°C) to 15°C in 10–20 minutes from device insertion. Rectal temperature was maintained at 15±3°C during active cooling. MRI thermometry tests revealed a steep temperature gradient with increasing distance from the cooling device, with the desired temperature range maintained within the surrounding few millimeters. Conclusion: A 3D printed rectal cooling device was fabricated for the purpose of inducing local hypothermia in rat rectums. Rectal cooling capabilities were characterized in-vivo to facilitate an investigation of the radioprotective effect of hypothermia for late rectal

  17. Novel approach for independent control of brain hypothermia and systemic normothermia: cerebral selective deep hypothermia for refractory cardiac arrest

    PubMed Central

    Wang, Chih-Hsien; Lin, Yu-Ting; Chou, Heng-Wen; Wang, Yi-Chih; Hwang, Joey-Jen; Gilbert, John R; Chen, Yih-Sharng

    2017-01-01

    A 38-year-old man was found unconscious, alone in the driver's seat of his car. The emergency medical team identified his condition as pulseless ventricular tachycardia. Defibrillation was attempted but failed. Extracorporeal membrane oxygenation (ECMO) was started in the emergency room 52 min after the estimated arrest following the extracorporeal cardiopulmonary resuscitation (ECPR) protocol in our center. The initial prognosis under the standard protocol was <25% chance of survival. A novel adjunctive to our ECPR protocol, cerebral selective deep (<30°C) hypothermia (CSDH), was applied. CSDH adds a second independent femoral access extracorporeal circuit, perfusing cold blood into the patient's common carotid artery. The ECMO and CSDH circuits demonstrated independent control of cerebral and core temperatures. Nasal temperature was lowered to below 30°C for 12 hours while core was maintained at normothermia. The patient was discharged without significant neurological deficit 32 days after the initial arrest. PMID:28108436

  18. Novel approach for independent control of brain hypothermia and systemic normothermia: cerebral selective deep hypothermia for refractory cardiac arrest.

    PubMed

    Wang, Chih-Hsien; Lin, Yu-Ting; Chou, Heng-Wen; Wang, Yi-Chih; Hwang, Joey-Jen; Gilbert, John R; Chen, Yih-Sharng

    2017-01-20

    A 38-year-old man was found unconscious, alone in the driver's seat of his car. The emergency medical team identified his condition as pulseless ventricular tachycardia. Defibrillation was attempted but failed. Extracorporeal membrane oxygenation (ECMO) was started in the emergency room 52 min after the estimated arrest following the extracorporeal cardiopulmonary resuscitation (ECPR) protocol in our center. The initial prognosis under the standard protocol was <25% chance of survival. A novel adjunctive to our ECPR protocol, cerebral selective deep (<30°C) hypothermia (CSDH), was applied. CSDH adds a second independent femoral access extracorporeal circuit, perfusing cold blood into the patient's common carotid artery. The ECMO and CSDH circuits demonstrated independent control of cerebral and core temperatures. Nasal temperature was lowered to below 30°C for 12 hours while core was maintained at normothermia. The patient was discharged without significant neurological deficit 32 days after the initial arrest.

  19. Novel approach for independent control of brain hypothermia and systemic normothermia: cerebral selective deep hypothermia for refractory cardiac arrest.

    PubMed

    Wang, Chih-Hsien; Lin, Yu-Ting; Chou, Heng-Wen; Wang, Yi-Chih; Hwang, Joey-Jen; Gilbert, John R; Chen, Yih-Sharng

    2017-01-25

    A 38-year-old man was found unconscious, alone in the driver's seat of his car. The emergency medical team identified his condition as pulseless ventricular tachycardia. Defibrillation was attempted but failed. Extracorporeal membrane oxygenation (ECMO) was started in the emergency room 52 min after the estimated arrest following the extracorporeal cardiopulmonary resuscitation (ECPR) protocol in our center. The initial prognosis under the standard protocol was <25% chance of survival. A novel adjunctive to our ECPR protocol, cerebral selective deep (<30°C) hypothermia (CSDH), was applied. CSDH adds a second independent femoral access extracorporeal circuit, perfusing cold blood into the patient's common carotid artery. The ECMO and CSDH circuits demonstrated independent control of cerebral and core temperatures. Nasal temperature was lowered to below 30°C for 12 hours while core was maintained at normothermia. The patient was discharged without significant neurological deficit 32 days after the initial arrest.

  20. Survey on Hypothermia and Hyperthermia in Poisoned Patients in a Unique Referral Hospital, Tehran, Iran

    PubMed Central

    Mozafari, Naser; Talaie, Haleh; Shoaei, Simin Dokht; Hashemian, Morteza; Mahdavinejad, Arezou

    2016-01-01

    975 IU/L were recorded in 57.7% and 13.2% of subjects, respectively. Conclusions Body temperature changes in human poisonings are a matter in need of special attention. A literature review did not reveal any controversy over hypothermia, but poisoning cases exhibit a variety of patterns of fever and hyperthermia. If there are no limits to the diagnosis of fever and hyperthermia, all cases with a poor prognosis which fail to respond to treatment could be categorized as drug-induced hyperthermia. Therefore, a different approach is needed for poisoning cases. PMID:27275403

  1. ThermoSpots to Detect Hypothermia in Children with Severe Acute Malnutrition

    PubMed Central

    Mole, Thomas B.; Kennedy, Neil; Ndoya, Noel; Emond, Alan

    2012-01-01

    Introduction Hypothermia is a risk factor for increased mortality in children with severe acute malnutrition (SAM). Yet frequent temperature measurement remains unfeasible in under-resourced units in developing countries. ThermoSpot is a continuous temperature monitoring sticker designed originally for neonates. When applied to skin, its liquid crystals are designed to turn black with hypothermia and remain green with normothermia. Aims To (i) estimate the diagnostic accuracy of ThermoSpots for detecting WHO-defined hypothermia (core temperature <35.5°C or peripheral temperature <35.0°C) in children with SAM and (ii) determine their acceptability amongst mothers. Methods Children with SAM in a malnutrition unit in Malawi were enrolled during March-July 2010. The sensitivity and specificity of ThermoSpots were calculated by comparing the device colour against ‘gold standard’ rectal temperatures taken on admission and follow up peripheral temperatures taken until discharge. Guardians completed a questionnaire to assess acceptability. Results Hypothermia was uncommon amongst the 162 children enrolled. ThermoSpot successfully detected the one rectal temperature and two peripheral temperatures recorded that met the WHO definition of hypothermia. Overall, 3/846 (0.35%) temperature measurements were in the WHO-defined hypothermia range. Interpreting the brown transition colour (between black and green) as hypothermia improved sensitivities. For milder hypothermia definitions, sensitivities declined (<35.4°C, 50.0%; <35.9°C, 39.2%). Specificity was consistently above 94%. From questionnaires, 40/43 (93%) mothers reported they were 90–100% happy with the device overall. Free-text answers revealed themes of “Skin Rashes”, “User-satisfaction” and “Empowerment". Conclusion Although hypothermia was uncommon in this study, ThermoSpots successfully detected these episodes in malnourished children and were acceptable to mothers. Research in settings where

  2. The Role of Posttraumatic Hypothermia in Preventing Dendrite Degeneration and Spine Loss after Severe Traumatic Brain Injury

    PubMed Central

    Wang, Chuan-fang; Zhao, Cheng-cheng; Jiang, Gan; Gu, Xiao; Feng, Jun-feng; Jiang, Ji-yao

    2016-01-01

    Posttraumatic hypothermia prevents cell death and promotes functional outcomes after traumatic brain injury (TBI). However, little is known regarding the effect of hypothermia on dendrite degeneration and spine loss after severe TBI. In the present study, we used thy1-GFP transgenic mice to investigate the effect of hypothermia on the dendrites and spines in layer V/VI of the ipsilateral cortex after severe TBI. We found that hypothermia (33 °C) dramatically prevented dendrite degeneration and spine loss 1 and 7 days after CCI. The Morris water maze test revealed that hypothermia preserved the learning and memory functions of mice after CCI. Hypothermia significantly increased the expression of the synaptic proteins GluR1 and PSD-95 at 1 and 7 days after CCI in the ipsilateral cortex and hippocampus compared with that of the normothermia TBI group. Hypothermia also increased cortical and hippocampal BDNF levels. These results suggest that posttraumatic hypothermia is an effective method to prevent dendrite degeneration and spine loss and preserve learning and memory function after severe TBI. Increasing cortical and hippocampal BDNF levels might be the mechanism through which hypothermia prevents dendrite degeneration and spine loss and preserves learning and memory function. PMID:27833158

  3. Remote Postconditioning Alone and Combined with Hypothermia Improved Postresuscitation Cardiac and Neurological Outcomes in Swine.

    PubMed

    Xu, Jiefeng; Huang, Zeng; Ye, Sen; Wang, Moli; Fang, Ya; Li, Zilong

    2016-01-01

    Objective. Previously, we demonstrated that remote ischemic postconditioning (RIpostC) improved postresuscitation myocardial and cerebral functions in rat. Here, we investigated the effects of RIpostC alone and combined with therapeutic hypothermia (TH) on cardiac and neurological outcomes after CPR in swine. Methods. Twenty-one pigs were subjected to 10 mins of VF and then 5 mins of CPR. The animals were randomized to receive RIpostC alone, or its combination with TH, or sham control. RIpostC was induced by 4 cycles of limb ischemia followed by reperfusion. TH was implemented by surface cooling to reach a temperature of 32-34°C. Results. During 72 hrs after resuscitation, lower level of cardiac troponin I and greater stroke volume and global ejection fraction were observed in animals that received RIpostC when compared to the control. RIpostC also decreased serum levels of neuron-specific enolase and S100B and increased neurologic alertness score after resuscitation. The combination of RIpostC and TH resulted in greater improvement in cardiac and neurological outcomes than RIpostC alone. Conclusion. RIpostC was conducive to improving postresuscitation myocardial and cerebral functions and reducing their organ injuries. Its combination with TH further enhanced its protective effects.

  4. Remote Postconditioning Alone and Combined with Hypothermia Improved Postresuscitation Cardiac and Neurological Outcomes in Swine

    PubMed Central

    Xu, Jiefeng; Huang, Zeng; Ye, Sen; Wang, Moli; Fang, Ya

    2016-01-01

    Objective. Previously, we demonstrated that remote ischemic postconditioning (RIpostC) improved postresuscitation myocardial and cerebral functions in rat. Here, we investigated the effects of RIpostC alone and combined with therapeutic hypothermia (TH) on cardiac and neurological outcomes after CPR in swine. Methods. Twenty-one pigs were subjected to 10 mins of VF and then 5 mins of CPR. The animals were randomized to receive RIpostC alone, or its combination with TH, or sham control. RIpostC was induced by 4 cycles of limb ischemia followed by reperfusion. TH was implemented by surface cooling to reach a temperature of 32–34°C. Results. During 72 hrs after resuscitation, lower level of cardiac troponin I and greater stroke volume and global ejection fraction were observed in animals that received RIpostC when compared to the control. RIpostC also decreased serum levels of neuron-specific enolase and S100B and increased neurologic alertness score after resuscitation. The combination of RIpostC and TH resulted in greater improvement in cardiac and neurological outcomes than RIpostC alone. Conclusion. RIpostC was conducive to improving postresuscitation myocardial and cerebral functions and reducing their organ injuries. Its combination with TH further enhanced its protective effects. PMID:28097144

  5. Temperature control during therapeutic hypothermia for newborn encephalopathy using different Blanketrol devices.

    PubMed

    Laptook, Abbot R; Kilbride, Howard; Shepherd, Edward; McDonald, Scott A; Shankaran, Seetha; Truog, William; Das, Abhik; Higgins, Rosemary D

    2014-12-01

    Therapeutic hypothermia improves the survival and neurodevelopmental outcome of infants with newborn encephalopathy of a hypoxic-ischemic origin. The NICHD Neonatal Research Network (NRN) Whole Body Cooling trial used the Cincinnati Sub-Zero Blanketrol II to achieve therapeutic hypothermia. The Blanketrol III is now available and provides additional cooling modes that may result in better temperature control. This report is a retrospective comparison of infants undergoing hypothermia using two different cooling modes of the Blanketrol device. Infants from the NRN trial were cooled with the Blanketrol II using the Automatic control mode (B2 cohort) and were compared with infants from two new NRN centers that adopted the NRN protocol and used the Blanketrol III in a gradient mode (B3 cohort). The primary outcome was the percent time the esophageal temperature stayed between 33°C and 34°C (target 33.5°C) during maintenance of hypothermia. Cohorts had similar birth weight, gestational age, and level of encephalopathy at the initiation of therapy. Baseline esophageal temperature differed between groups (36.6°C ± 1.0°C for B2 vs. 33.9°C ± 1.2°C for B3, p<0.0001) reflecting the practice of passive cooling during transport prior to initiation of active device cooling in the B3 cohort. This difference prevented comparison of temperatures during induction of hypothermia. During maintenance of hypothermia the mean and standard deviation of the percent time between 33°C and 34°C was similar for B2 compared to B3 cohorts (94.8% ± 0.1% vs. 95.8% ± 0.1%, respectively). Both the automatic and gradient control modes of the Blanketrol devices appear comparable in maintaining esophageal temperature within the target range during maintenance of therapeutic hypothermia.

  6. Victims of lethal hypothermia have decreased levels of thrombomodulin in myocardium and urine.

    PubMed

    Pakanen, Lasse; Kaija, Helena; Kortelainen, Marja-Leena; Särkioja, Terttu; Porvari, Katja

    2015-03-01

    Severe cold stress has been shown to cause changes in the expression and secretion of thrombomodulin (TM), an endothelial protein regulating haemostasis and inflammation. To further evaluate TM as a cold stress indicator, relative TM mRNA and TM protein levels in the myocardium and the concentrations of TM in serum and urine were analysed in different causes of death (hypothermia main cause, n = 80; hypothermia contributory cause, n = 26; cardiovascular disease (CVD) main cause, n = 94; trauma main cause, n = 45; other main cause, n = 25). Urinary catecholamine concentrations and myocardial heat shock factor 1 (HSF1) transcript levels were also studied. The TM mRNA and the TM protein levels in myocardium and urine were significantly lower in hypothermia deaths than those in the controls. Post-mortem interval did not correlate with urinary TM concentration. The sensitivity and specificity of urinary TM assay to detect hypothermia deaths were 70.8 and 70.3 %, respectively. Catecholamine concentrations in urine correlated significantly with TM concentration in urine and TM mRNA levels in all groups excluding CVD deaths. There were no differences in the HSF1 transcript levels and no correlation to TM levels. These findings provide further evidence that cold stress and hypothermia affect TM expression and secretion and that they are possibly linked to catecholamine action. Thus, measuring post-mortem TM levels may provide additional support to diagnosing hypothermia in medico-legal examination. The results may also provide additional knowledge for the treatment of hypothermic patients and the use of hypothermia for medical purposes.

  7. Brain injury following trial of hypothermia for neonatal hypoxic–ischaemic encephalopathy

    PubMed Central

    Shankaran, Seetha; Barnes, Patrick D; Hintz, Susan R; Laptook, Abbott R; Zaterka-Baxter, Kristin M; McDonald, Scott A; Ehrenkranz, Richard A; Walsh, Michele C; Tyson, Jon E; Donovan, Edward F; Goldberg, Ronald N; Bara, Rebecca; Das, Abhik; Finer, Neil N; Sanchez, Pablo J; Poindexter, Brenda B; Van Meurs, Krisa P; Carlo, Waldemar A; Stoll, Barbara J; Duara, Shahnaz; Guillet, Ronnie; Higgins, Rosemary D

    2013-01-01

    Objective The objective of our study was to examine the relationship between brain injury and outcome following neonatal hypoxic–ischaemic encephalopathy treated with hypothermia. Design and patients Neonatal MRI scans were evaluated in the National Institute of Child Health and Human Development (NICHD) randomised controlled trial of whole-body hypothermia and each infant was categorised based upon the pattern of brain injury on the MRI findings. Brain injury patterns were assessed as a marker of death or disability at 18–22 months of age. Results Scans were obtained on 136 of 208 trial participants (65%); 73 in the hypothermia and 63 in the control group. Normal scans were noted in 38 of 73 infants (52%) in the hypothermia group and 22 of 63 infants (35%) in the control group. Infants in the hypothermia group had fewer areas of infarction (12%) compared to infants in the control group (22%). Fifty-one of the 136 infants died or had moderate or severe disability at 18 months. The brain injury pattern correlated with outcome of death or disability and with disability among survivors. Each point increase in the severity of the pattern of brain injury was independently associated with a twofold increase in the odds of death or disability. Conclusions Fewer areas of infarction and a trend towards more normal scans were noted in brain MRI following whole-body hypothermia. Presence of the NICHD pattern of brain injury is a marker of death or moderate or severe disability at 18–22 months following hypothermia for neonatal encephalopathy. PMID:23080477

  8. Treatments (12 and 48 h) with systemic and brain-selective hypothermia techniques after permanent focal cerebral ischemia in rat.

    PubMed

    Clark, Darren L; Penner, Mark; Wowk, Shannon; Orellana-Jordan, Ian; Colbourne, Frederick

    2009-12-01

    Mild hypothermia lessens brain injury when initiated after the onset of global or focal ischemia. The present study sought to determine whether cooling to approximately 33 degrees C provides enduring benefit when initiated 1 h after permanent middle cerebral artery occlusion (pMCAO, via electrocautery) in adult rats and whether protection depends upon treatment duration and cooling technique. In the first experiment, systemic cooling was induced in non-anesthetized rats through a whole-body exposure technique that used fans and water mist. In comparison to normothermic controls, 12- and 48-h bouts of hypothermia significantly lessened functional impairment, such as skilled reaching ability, and lesion volume out to a 1-month survival. In the second experiment, brain-selective cooling was induced in awake rats via a water-cooled metal strip implanted underneath the temporalis muscle overlying the ischemic territory. Use of a 48-h cooling treatment significantly mitigated injury and behavioral impairment whereas a 12-h treatment did not. These findings show that while systemic and focal techniques are effective when initiated after the onset of pMCAO, they differ in efficacy depending upon the treatment duration. A direct and uncomplicated comparison between methods is problematic, however, due to unknown gradients in brain temperature and the use of two separate experiments. In summary, prolonged cooling, even when delayed after onset of pMCAO, provides enduring behavioral and histological protection sufficient to suggest that it will be clinically effective. Nonetheless, further pre-clinical work is needed to improve treatment protocols, such as identifying the optimal depth of cooling, and how these factors interact with cooling method.

  9. Head cooling with mild systemic hypothermia in anesthetized piglets is neuroprotective.

    PubMed

    Tooley, James R; Satas, Saulius; Porter, Helen; Silver, Ian A; Thoresen, Marianne

    2003-01-01

    Hypothermia is potentially therapeutic in the management of neonatal hypoxic-ischemic brain injury. However, not all studies have shown a neuroprotective effect. It is suggested that the stress of unsedated hypothermia may interfere with neuroprotection. We propose that selective head cooling (SHC) combined with mild total-body hypothermia during anesthesia enhances local neuroprotection while minimizing the occurrence of systemic side effects and stress associated with unsedated whole-body cooling. Our objective was to determine whether SHC combined with mild total-body hypothermia while anesthetized for a period of 24 hours reduces cerebral damage in our piglet survival model of global hypoxia-ischemia. Eighteen anesthetized piglets received a 45-minute global hypoxic-ischemic insult. The pigs were randomized either to remain normothermic or to receive SHC. We found that the severity of the hypoxic-ischemic insult was similar in the SHC versus the normothermic group, and that the mean neurology scores at 30 and 48 hours and neuropathology scores were significantly better in the SHC group versus the normothermic group. We conclude that selective head cooling combined with mild systemic hypothermia and anesthesia is neuroprotective when started immediately after the insult in our piglet model of hypoxic-ischemic encephalopathy.

  10. Factors at scene and in transfer related to the development of hypothermia in major burns

    PubMed Central

    Steele, J.E.; Atkins, J.L.; Vizcaychipi, M.P.

    2016-01-01

    Summary There is a paucity of evidence regarding incidence and causes of hypothermia in patients with major burns and its impact on outcomes. This paper identifies contributing factors to hypothermia and its relationship with the severity of physiological scoring systems on admission to a tertiary centre. Patients with burns >20% TBSA admitted between March 2010 and July 2013 comprised this retrospective survey. Data relating to causative factors at time of burn, during transfer, physiological outcome scores (BOBI, SOFA, RTS and APACHE II), length of hospital stay and mortality were collected. SPSS statistical software was used for analysis. The study included 31 patients (medians: age 32 years, burn size 30% TBSA). 13% (n=4) of patients died during hospital admission. 42% (n=13) of patients had a temperature <36.0C on arrival. Temperature on arrival at the burns centre was related to the severity of all physiological scores (p=<0.001). There was no difference between groups in terms of mortality in hospital (p=0.151) or length of hospital stay (p=0.547). Our results show that hypothermia is related to burn severity and patient physiological status. They do not show a relationship between hypothermia and external factors at the time of the burn. This paper prompts further investigation into the prevention of hypothermia in patients with major burns. PMID:28149230

  11. The Role of Hypothermia Coordinator: A Case of Hypothermic Cardiac Arrest Treated with ECMO.

    PubMed

    Darocha, Tomasz; Kosinski, Sylweriusz; Moskwa, Maciej; Jarosz, Anna; Sobczyk, Dorota; Galazkowski, Robert; Slowik, Marcin; Drwila, Rafal

    2015-12-01

    We present a description of emergency medical rescue procedures in a patient suffering from severe hypothermia who was found in the Babia Gora mountain range (Poland). After diagnosing the symptoms of II/III stage hypothermia according to the Swiss Staging System, the Mountain Rescue Service notified the coordinator from the Severe Accidental Hypothermia Center (CLHG) Coordinator in Krakow and then kept in constant touch with him. In accordance with the protocol for managing such situations, the coordinator started the procedure for patients in severe hypothermia with the option of extracorporeal warming and secured access to a device for continuous mechanical chest compression. After reaching the hospital, extracorporeal warming with ECMO support in the arteriovenuous configuration was started. The total duration of circulatory arrest was 150 minutes. The rescue procedures were supervised by the coordinator, who was on 24-hour duty and was reached by means of an alarm phone. The task of the coordinator is to consult the management of hypothermia cases, use his knowledge and experience to help in the diagnosis and treatment. and if the need arises refer the patient for ECMO at CLHG. Good coordination, planning, predicting possible problems, and acting in accordance with the agreed procedures in the scheme, make it possible to shorten the time of reaching the destination hospital and implement effective treatment.

  12. Hypothermia reduces cerebral metabolic rate and cerebral blood flow in newborn pigs

    SciTech Connect

    Busija, D.W.; Leffler, C.W. )

    1987-10-01

    The authors examined effects of hypothermia on cerebral metabolic rate and cerebral blood flow in anesthetized, newborn pigs (1-4 days old). Cerebral blood flow (CBF) was determined with 15-{mu}m radioactive microspheres. Regional CBF ranged from 44 to 66 ml{center dot}min{sup {minus}1}{center dot}100 g{sup {minus}1}, and cerebral metabolic rate was 1.94 {plus minus} 0.23 ml O{sub 2}{center dot}100 g{sup {minus}1}{center dot}min{sup {minus}1} during normothermia (39{degree}C). Reduction of rectal temperature to 34-35{degree}C decreased CBF and cerebral metabolic rate 40-50%. In another group of piglets, they examined responsiveness of the cerebral circulation to arterial hypercapnia during hypothermia. Although absolute values for normocapnic and hypercapnic CBF were reduced by hypothermia and absolute values for normocapnic and hypercapnic cerebrovascular resistance were increased, the percentage changes from control in these variables during hypercapnia were similar during normothermia and hypothermia. In another group of animals that were maintained normothermic and exposed to two episodes of hypercapnia, there was no attenuation of cerebrovascular dilation during the second episode. They conclude that hypothermia reduces CBF secondarily to a decrease in cerebral metabolic rate and that percent dilator responsiveness to arterial hypercapnia is unaltered when body temperature is reduced.

  13. The Physiologic Effects of Isoflurane, Sevoflurane, and Hypothermia Used for Anesthesia in Neonatal Rats (Rattus norvegicus).

    PubMed

    Huss, Monika K; Chum, Helen H; Chang, Angela G; Jampachairsi, Katechan; Pacharinsak, Cholawat

    2016-01-01

    Information regarding effective anesthetic regimens for neonatal rat pups is limited. Here we investigated whether isoflurane or sevoflurane anesthesia maintains physiologic parameters more consistently than does hypothermia anesthesia in neonatal rat pups. Rat pups (age, 4 d) were randomly assigned to receive isoflurane, sevoflurane, or hypothermia. Physiologic parameters monitored at 1, 5, 10, and 15 min included heart rate (HR), respiratory rate (RR), and oxygen saturation (%SpO2). Other parameters evaluated were loss and return of righting reflex, paw withdrawal reflex, and maternal acceptance. Corticosterone and glucose were sampled at 20 min and 24 h after anesthesia induction. Once a surgical plane of anesthesia was achieved, a skin incision was made on the right lateral thigh. After the procedure, all pups were accepted and cared for by their dam. Isoflurane- and sevoflurane-treated pups maintained higher HR, RR, %SpO2, and glucose levels than did hypothermia-treated pups. For both the isoflurane and sevoflurane groups, HR and RR were significantly lower at 10 and 15 min after anesthesia than at 1 min. Compared with hypothermia, isoflurane and sevoflurane anesthesia provided shorter times to loss of and return of the righting reflex. Although corticosterone did not differ among the groups, glucose levels were higher at 20 min after anesthesia induction than at 24 h in all anesthetic groups. We conclude that both isoflurane and sevoflurane anesthesia maintain physiologic parameters (HR, RR, %SpO2) more consistently than does hypothermia anesthesia in 4-d-old rat pups.

  14. Effect of hypothermia on cell kinetics and response to hyperthermia and x rays

    SciTech Connect

    van Rijn, J.; van den Berg, J.; Kipp, J.B.A.; Schamhart, D.H.J.; van Wijk, R.

    1985-02-01

    Hyperthermia is a potent radio enhancer. Studies using hypothermia in combination with irradiation have given confusing results due to lack of uniformity in experimental design. This report shows that hypothermia might have potential significance in the treatment of malignant cells with both thermo- and radiotherapy. Reuber H35 hepatoma cells, clone KRC-7 were used to study the effect of hypothermia on cell kinetics and subsequent response to hyperthermia and/or X rays. Cells were incubated at 8.5/sup 0/C or between 25 and 37/sup 0/C for 24 hr prior to hyperthermia or irradiation. Hypothermia caused sensitization to both hyperthermia and X rays. In contrast to the effect of hypothermia on either hyperthermia or X rays alone, thermal radiosensitization was decreased in hypothermically pretreated cells (24 hr at 25/sup 0/C) compared to control cells (37/sup 0/C). The expression of thermotolerance and the rate of development at 37/sup 0/C after an initial heating at 42.5/sup 0/C were not influenced after preincubation at 25/sup 0/C for 24 hr. The expression of thermotolerance for heat or heat plus X rays during incubation at 41/sup 0/C occurred in a significantly smaller number of cells after 24 hr preincubation at 25/sup 0/C. The enhanced thermo- and radiosensitivity in hypothermically treated cells disappeared in approximately 6 hr after return to 37/sup 0/C.

  15. Hypothermia and afterdrop following open water swimming: the Alcatraz/San Francisco Swim Study.

    PubMed

    Nuckton, T J; Claman, D M; Goldreich, D; Wendt, F C; Nuckton, J G

    2000-10-01

    To determine whether or not participants in open water swim events experience hypothermia and afterdrop, rectal temperature was measured for up to 45 minutes in 11 subjects following the New Year's Day Alcatraz Swim. This event was held in open water (11.7 degrees C [53.0 degrees F]) in the San Francisco Bay, and participants did not wear wetsuits or other protective clothing. Biophysical parameters, including surfacelvolume ratio, body mass index, and percent body fat were measured before the swim, and statistical analysis was done to determine predictors of temperature decrease and afterdrop duration. Applying the American Heart Association definition of hypothermia (less than 36.0 C [96.8 degrees F]), hypothermia was seen in 5 of the 11 subjects. Using a more rigorous and traditional definition (less than 35.0 degrees C [95.0 degrees F]), hypothermia was seen in only one subject. Afterdrop, defined as continued cooling following removal from cold stress, was seen in 10 of the 11 subjects. Surface/volume ratio (S/V) and body mass index (BMI) predicted the lowest recorded temperatures (P < .05; r(S/V) = -.71, r(BMI) = .72) and afterdrop duration (P < .05; r(SN) = -.75, r(BMI) = .69). These results suggest that hypothermia and afterdrop can occur commonly after recreational open water swimming, and that participants should be observed for signs of temperature decrease following removal from cold stress.

  16. Therapeutic Hypothermia in Spinal Cord Injury: The Status of Its Use and Open Questions

    PubMed Central

    Wang, Jiaqiong; Pearse, Damien D.

    2015-01-01

    Spinal cord injury (SCI) is a major health problem and is associated with a diversity of neurological symptoms. Pathophysiologically, dysfunction after SCI results from the culmination of tissue damage produced both by the primary insult and a range of secondary injury mechanisms. The application of hypothermia has been demonstrated to be neuroprotective after SCI in both experimental and human studies. The myriad of protective mechanisms of hypothermia include the slowing down of metabolism, decreasing free radical generation, inhibiting excitotoxicity and apoptosis, ameliorating inflammation, preserving the blood spinal cord barrier, inhibiting astrogliosis, promoting angiogenesis, as well as decreasing axonal damage and encouraging neurogenesis. Hypothermia has also been combined with other interventions, such as antioxidants, anesthetics, alkalinization and cell transplantation for additional benefit. Although a large body of work has reported on the effectiveness of hypothermia as a neuroprotective approach after SCI and its application has been translated to the clinic, a number of questions still remain regarding its use, including the identification of hypothermia’s therapeutic window, optimal duration and the most appropriate rewarming rate. In addition, it is necessary to investigate the neuroprotective effect of combining therapeutic hypothermia with other treatment strategies for putative synergies, particularly those involving neurorepair. PMID:26213924

  17. Nocturnal hypothermia impairs flight ability in birds: a cost of being cool

    PubMed Central

    Carr, Jennie M.; Lima, Steven L.

    2013-01-01

    Many birds use regulated drops in night-time body temperature (Tb) to conserve energy critical to winter survival. However, a significant degree of hypothermia may limit a bird's ability to respond to predatory attack. Despite this likely energy–predation trade-off, the behavioural costs of avian hypothermia have yet to be examined. We thus monitored the nocturnal hypothermia of mourning doves (Zenaida macroura) in a laboratory setting in response to food deprivation. Nocturnal flight tests were used to quantify the flight ability of hypothermic doves. Many hypothermic doves (39% of tests) could not fly while carrying a small weight, but could do so after quickly warming up to typical daytime Tb. Doves that were unable to fly during their first test were more hypothermic than those that could fly, with average Tb reductions of 5.3°C and 3.3°C, respectively, but there was no overall indication of a threshold Tb reduction beyond which doves were consistently incapable of flight. These results suggest that energy-saving hypothermia interferes with avian antipredator behaviour via a reduction in flight ability, likely leading to a trade-off between energy-saving hypothermia and the risk of predation. PMID:24107528

  18. Effects of mild hypothermia therapy on the levels of glutathione in rabbit blood and cerebrospinal fluid after cardiopulmonary resuscitation

    PubMed Central

    Zhao, Hui; Chen, Yueliang

    2015-01-01

    Objective(s): The aim of this study was to investigate the effects of mild hypothermia therapy on oxidative stress injury of rabbit brain tissue after cardiopulmonary resuscitation (CPR). Materials and Methods: Rabbit models of cardiac arrest were established. After the restoration of spontaneous circulation, 50 rabbits were randomly divided into normothermia and hypothermia groups. The following five time points were selected: before CPR, immediately after CPR, 2 hr after CPR (hypothermia group reached the target temperature), 14 hr after CPR (hypothermia group before rewarming), and 24 hr after CPR (hypothermia group recovered to normal temperature). Glutathione (GSH) concentrations in both the blood and cerebrospinal fluid of the normothermia and hypothermia groups were measured. Results: At 2, 14, and 24 hr after CPR, the GSH concentrations in both the blood and cerebrospinal fluid were significantly higher in the hypothermia group than in the nomorthermia group. Conclusion: Mild hypothermia therapy may increase GSH concentrations in rabbit blood and cerebrospinal fluid after CPR as well as promote the recovery of cerebral function. PMID:25810895

  19. Perioperative hypothermia and incidence of surgical wound infection: a bibliographic study

    PubMed Central

    da Silva, Aline Batista; Peniche, Aparecida de Cassia Giani

    2014-01-01

    The purpose of this review article was to understand and analyze the scientific production related to the occurrence of perioperative hypothermia and the incidence of infection on the surgical site. For this purpose, a search was conducted in the databases LILACS, MEDLINE, PubMed, CINAHL and Cochrane, using the health science descriptors DECS, from 2004 to 2009. A total of 91 articles were found. After eliminating duplicate items and using selection criteria for inclusion, six manuscripts remained for analysis. The studies were classified as retrospective, prospective, case studies, and clinical trials. After analysis, the majority of studies showed that hypothermia must be prevented during the perioperative period to reduce complications in the healing process of the surgical incision. Therefore, unadverted hypothermia directly influences in surgical site healing, increasing the incidence of infection in the surgical wound. PMID:25628208

  20. Perioperative hypothermia and incidence of surgical wound infection: a bibliographic study.

    PubMed

    Silva, Aline Batista da; Peniche, Aparecida de Cassia Giani

    2014-01-01

    The purpose of this review article was to understand and analyze the scientific production related to the occurrence of perioperative hypothermia and the incidence of infection on the surgical site. For this purpose, a search was conducted in the databases LILACS, MEDLINE, PubMed, CINAHL and Cochrane, using the health science descriptors DECS, from 2004 to 2009. A total of 91 articles were found. After eliminating duplicate items and using selection criteria for inclusion, six manuscripts remained for analysis. The studies were classified as retrospective, prospective, case studies, and clinical trials. After analysis, the majority of studies showed that hypothermia must be prevented during the perioperative period to reduce complications in the healing process of the surgical incision. Therefore, unadverted hypothermia directly influences in surgical site healing, increasing the incidence of infection in the surgical wound.

  1. [Severe apparent life-threatening event during "skin-to-skin": treatment with hypothermia].

    PubMed

    Marin, N; Valverde, E; Cabañas, F

    2013-10-01

    'Skin-to-skin' in healthy newborn infants is currently routine practice in Spanish maternity wards. This practice has shown benefits in increasing the duration of breast-feeding and maternal bonding behaviour with no significant adverse events. Early sudden deaths and severe apparent life-threatening events (ALTE) during the first 24 hours of life are infrequent, but well recognised. Risk factors during 'skin to skin' have been established. These events can lead to high neonatal morbidity and mortality. Hypothermia is now the standard of care for moderate to severe hypoxic-ischaemic encephalopathy and has shown to reduce mortality and neurological morbidity in children with hypoxic-ischaemic brain injury. Although there are no clinical trials that evaluate hypothermia after a severe ALTE, neonates who suffer it should be considered for this treatment. We present a case of a healthy newborn who had an ALTE during skin-to-skin with his mother and was treated with hypothermia.

  2. Hypothermia-related deaths--New Mexico, October 1993-March 1994.

    PubMed

    1995-12-22

    Hypothermia is an unintentional lowering of the body temperature to < or = 95 F (< or = 35 C) (1). From 1979 through 1992, 10,550 persons in the United States died from hypothermia, an average of 754 deaths per year (range: 557-1021). Most of these deaths occurred during winter months in three distinct climatic areas: northern states characterized by moderate to severe cold temperatures during winter (e.g., Illinois and New York); southern states where rapid changes in temperature occur because of the effects of weather systems (e.g., North Carolina, South Carolina, and Virginia); and western states in areas of high elevations and profound declines in temperatures at night (e.g., New Mexico and Arizona). From October 1993 through March 1994, a total of 23 deaths attributed to hypothermia were reported to the New Mexico Office of the Medical Investigator. This report summarizes the investigations of four of these deaths and the epidemiology for all 23 cases.

  3. Cerebral Hemodynamics in Asphyxiated Newborns Undergoing Hypothermia Therapy: Pilot Findings Using a Multiple-Time-Scale Analysis

    PubMed Central

    Chalak, Lina F; Tian, Fenghua; Tarumi, Takashi; Zhang, Rong

    2015-01-01

    Background Improved quantitative assessment of cerebral hemodynamics in newborns might enable us to optimize cerebral perfusion. Our objective was to develop an approach to assess cerebral hemodynamics across multiple time scales during the first 72 hours of life in newborns during hypothermia therapy. Methods Spontaneous oscillations in mean arterial pressure (MAP) and regional cerebral tissue oxygen saturation (SctO2) were analyzed using a moving window correlation (MWC) method with time scales ranging from 0.15 to 8 hours in this pilot methodology study. Abnormal neurodevelopmental outcome was defined by Bayley III scores and/or cerebral palsy by 24 months of age using receiver operating curve (ROC). Results Multiple-time-scale correlations between MAP and SctO2 oscillations were tested in 10 asphyxiated newborns undergoing hypothermia therapy. Large non induced fluctuations in the blood pressure were observed during cooling in all five infants with abnormal outcomes. Notably, these infants had two distinct patterns of correlation: a positive in-phase correlation at the short time scales (15 min), and/or a negative anti-phase correlations observed at long time scales (4 hrs.). Both the in-phase (AUC 0.6, [95% CI 0.2–0.95]) and anti-phase correlations (AUC 0.75, [95% CI 0.4–0.95]) appeared to be related to an abnormal outcome. Conclusions Our observations suggest that the time scale is an important factor that needs to be standardized in the assessment of neonatal cerebral hemodynamics. PMID:26858217

  4. The effects of QuikClot Combat Gauze on hemorrhage control in the presence of hemodilution and hypothermia

    PubMed Central

    Johnson, Don; Bates, Sheri; Nukalo, Sofiya; Staub, Amy; Hines, Aaron; Leishman, Taylor; Michel, Jennifer; Sikes, Dusti; Gegel, Brian; Burgert, James

    2014-01-01

    Hemorrhage is the leading cause of death from trauma. Intravenous (IV) fluid resuscitation in these patients may cause hemodilution and secondary hemorrhage. In addition, hypothermia may interfere with coagulation. The purposes of this study were to compare the effectiveness QuikClot Combat Gauze (QCG) to a control group on hemorrhage in a hemodiluted, hypothermic model, and to determine the effects of IV volume resuscitation on rebleeding. This was a prospective, between subjects, experimental design. Yorkshire swine were randomly assigned to two groups: QCG (n = 13) or control (n = 13). The subjects were anesthetized. Hypothermia (temperature of ≤34.0 °C) was induced; 30% of their blood volume was exsanguinated. A 3:1 replacement of Lactated Ringer's was administered to dilute the remaining blood. The femoral artery and vein were transected. After 1 min of uncontrolled hemorrhage, QCG was placed into the wound followed by standard wound packing. The control group underwent the same procedures without QCG. After 5 min of manual pressure, a pressure dressing was applied. Following 30 min, the dressings were removed, and blood loss was calculated. For subjects achieving hemostasis, up to 5 L of IV fluid was administered or until bleeding occurred, which was defined as >2% total blood volume. The QCG had significantly less hemorrhage than the control (QCG = 30 ± 99 mL; control = 404 ± 406 mL) (p = .004). Further, the QCG group was able to tolerate more resuscitation fluid before hemorrhage (QCG = 4615 ± 1386 mL; control = 846 ± 1836) (p = .000). PMID:25568780

  5. Randomized Trial of Plastic Bags to Prevent Term Neonatal Hypothermia in a Resource-Poor Setting

    PubMed Central

    Belsches, Theodore C.; Tilly, Alyssa E.; Miller, Tonya R.; Kambeyanda, Rohan H.; Leadford, Alicia; Manasyan, Albert; Chomba, Elwyn; Ramani, Manimaran; Ambalavanan, Namasivayam

    2013-01-01

    OBJECTIVES: Term infants in resource-poor settings frequently develop hypothermia during the first hours after birth. Plastic bags or wraps are a low-cost intervention for the prevention of hypothermia in preterm and low birth weight infants that may also be effective in term infants. Our objective was to test the hypothesis that placement of term neonates in plastic bags at birth reduces hypothermia at 1 hour after birth in a resource-poor hospital. METHODS: This parallel-group randomized controlled trial was conducted at University Teaching Hospital, the tertiary referral center in Zambia. Inborn neonates with both a gestational age ≥37 weeks and a birth weight ≥2500 g were randomized 1:1 to either a standard thermoregulation protocol or to a standard thermoregulation protocol with placement of the torso and lower extremities inside a plastic bag within 10 minutes after birth. The primary outcome was hypothermia (<36.5°C axillary temperature) at 1 hour after birth. RESULTS: Neonates randomized to plastic bag (n = 135) or to standard thermoregulation care (n = 136) had similar baseline characteristics (birth weight, gestational age, gender, and baseline temperature). Neonates in the plastic bag group had a lower rate of hypothermia (60% vs 73%, risk ratio 0.76, confidence interval 0.60–0.96, P = .026) and a higher axillary temperature (36.4 ± 0.5°C vs 36.2 ± 0.7°C, P < .001) at 1 hour after birth compared with infants receiving standard care. CONCLUSIONS: Placement in a plastic bag at birth reduced the incidence of hypothermia at 1 hour after birth in term neonates born in a resource-poor setting, but most neonates remained hypothermic. PMID:23979082

  6. Adverse drug reactions in therapeutic hypothermia after cardiac arrest

    PubMed Central

    Witcher, Robert; Dzierba, Amy L.; Kim, Catherine; Smithburger, Pamela L.; Kane-Gill, Sandra L.

    2016-01-01

    Background: Therapeutic hypothermia (TH) improves survival and neurologic function in comatose survivors of cardiac arrest. Many medications used to support TH have altered pharmacokinetics and pharmacodynamics during this treatment. It is unknown if or at what frequency the medications used during TH cause adverse drug reactions (ADRs). Methods: A retrospective chart review was conducted for patients admitted to an intensive care unit (ICU) after cardiac arrest and treated with TH from January 2009 to June 2012 at two urban, university-affiliated, tertiary-care medical centres. Medications commonly used during TH were screened for association with significant ADRs (grade 3 or greater per Common Terminology Criteria for Adverse Events) using three published ADR detection instruments. Results: A total of 229 patients were included, the majority being males with median age of 62 presenting with an out-of-hospital cardiac arrest in pulseless electrical activity or asystole. The most common comorbidities were hypertension, coronary artery disease, and diabetes mellitus. There were 670 possible ADRs and 69 probable ADRs identified. Of the 670 possible ADRs, propofol, fentanyl, and acetaminophen were the most common drugs associated with ADRs. Whereas fentanyl, insulin, and propofol were the most common drugs associated with a probable ADR. Patients were managed with TH for a median of 22 hours, with 38% of patients surviving to hospital discharge. Conclusions: Patients undergoing TH after cardiac arrest frequently experience possible adverse reactions associated with medications and the corresponding laboratory abnormalities are significant. There is a need for judicious use and close monitoring of drugs in the setting of TH until recommendations for dose adjustments are available to help prevent ADRs.

  7. Therapeutic hypothermia after cardiac arrest in Long QT syndrome: Could it be an adjunctive treatment to prevent dysrhythmias?

    PubMed

    Jatti, Kumar; Prasad, Neeraj

    2015-01-01

    Therapeutic hypothermia has been used for neuroprotection following cardiac arrest presenting with ventricular tachycardia or ventricular fibrillation regardless of underlying cause. Long QT syndrome is a cause for polymorphic ventricular tachycardia, and we know that therapeutic hypothermia increases the QT interval. We managed a 27-year-old woman, who was 10 weeks post-partum, who collapsed secondary to ventricular fibrillation at home. Bystander cardiopulmonary resuscitation was started with successful resuscitation after a rescue shock from paramedics. On hospital admission, her computerised tomography head, computerised tomography pulmonary angiogram and echocardiography did not show any abnormality. Her baseline electrocardiogram showed prolonged QTc interval of 504 ms without ischaemic changes. After intubation and ventilation, she was treated with therapeutic hypothermia for 48 h. She had a further episode of polymorphic ventricular tachycardia requiring rescue shock just prior to starting therapeutic hypothermia in hospital. No dysrhythmias occurred during therapeutic hypothermia, although the QTc further increased. After stopping the therapeutic hypothermia, she had two further ventricular tachycardia episodes. After commencement of beta blockers, she remained free of arrhythmias, and an implantable cardioverter defibrillator was implanted, she has recovered without any neurological deficit. Ventricular dysrhythmias caused by prolongation of the QT interval during or after therapeutic hypothermia are not well understood. There has been a report of a patient also having ventricular dysrhythmia 2 h after re-warming post therapeutic hypothermia and also a report of arrhythmia free period during therapeutic hypothermia in a long QT syndrome patient; both these features are present in our patient. Re-warming is not usually known to cause any arrhythmias; however, it could be a problem in those with long QT syndrome. Whether therapeutic hypothermia has

  8. Delayed Treatment With Hypothermia Protects Against the No‐Reflow Phenomenon Despite Failure to Reduce Infarct Size

    PubMed Central

    Hale, Sharon L.; Herring, Michael J.; Kloner, Robert A.

    2013-01-01

    Background Many studies have shown that when hypothermia is started after coronary artery reperfusion (CAR), it is ineffective at reducing necrosis. However, some suggest that hypothermia may preferentially reduce no‐reflow. Our aim was to test the effects of hypothermia on no‐reflow when initiated close to reperfusion and 30 minutes after reperfusion, times not associated with a protective effect on myocardial infarct size. Methods and Results Rabbits received 30 minutes coronary artery occlusion/3 hours CAR. In protocol 1, hearts were treated for 1 hour with topical hypothermia (myocardial temperature ≈32°C) initiated at 5 minutes before or 5 minutes after CAR, and the results were compared with a normothermic group. In protocol 2, hypothermia was delayed until 30 minutes after CAR and control hearts remained normothermic. In protocol 1, risk zones were similar and infarct size was not significantly reduced by hypothermia initiated close to CAR. However, the no‐reflow defect was significantly reduced by 43% (5 minutes before CAR) and 38% (5 minutes after CAR) in hypothermic compared with normothermic hearts (P=0.004, ANOVA, P=ns between the 2 treated groups). In protocol 2, risk zones and infarct sizes were similar, but delayed hypothermia significantly reduced no‐reflow in hypothermic hearts by 30% (55±6% of the necrotic region in hypothermia group versus 79±6% with normothermia, P=0.008). Conclusion These studies suggest that treatment with hypothermia reduces no‐reflow even when initiated too late to reduce infarct size and that the microvasculature is especially receptive to the protective properties of hypothermia and confirm that microvascular damage is in large part a form of true reperfusion injury. PMID:23525431

  9. Cold-inducible RNA-binding protein inhibits neuron apoptosis through the suppression of mitochondrial apoptosis.

    PubMed

    Zhang, Hai-Tao; Xue, Jing-Hui; Zhang, Zhi-Wen; Kong, Hai-Bo; Liu, Ai-Jun; Li, Shou-Chun; Xu, Dong-Gang

    2015-10-05

    Cold-inducible RNA-binding protein (CIRP) is induced by mild hypothermia in several mammals, but the precise mechanism by which CIRP mediates hypothermia-induced neuroprotection remains unknown. We aimed to investigate the molecular mechanisms by which CIRP protects the nervous system during mild hypothermia. Rat cortical neurons were isolated and cultured in vitro under mild hypothermia (32°C). Apoptosis was measured by annexin V and propidium iodide staining, visualized by flow cytometry. Neuron ultrastructure was visualized by transmission electron microscopy. CIRP overexpression and knockdown were achieved via infection with pL/IRES/GFP-CIRP and pL/shRNA/F-CIRP-A lentivirus. RT(2) Profiler PCR Array Pathway Analysis and western blotting were used to evaluate the effects of CIRP overexpresion/knockdown on the neurons׳ transcriptome. Neuron late apoptosis was significantly reduced at day 7 of culture by 12h hypothermia, but neuron ultrastructure remained relatively intact. RT(2) Profiler PCR Array Pathway Analysis of 84 apoptosis pathway-associated factors revealed that mild hypothermia and CIRP overexpression induce similar gene expression profiles, specifically alterations of genes implicated in the mitochondrial apoptosis pathway. Mild hypothermia-treated neurons up-regulated 12 and down-regulated 38 apoptosis pathway-associated genes. CIRP-overexpressing neurons up-regulated 15 and down-regulated 46 genes. CIRP-knocked-down hypothermia-treated cells up-regulated 9 and down-regulated 40 genes. Similar results were obtained at the protein level. In conclusion, CIRP may inhibit neuron apoptosis through the suppression of the mitochondria apoptosis pathway during mild hypothermia.

  10. Better Glasgow outcome score, cerebral perfusion pressure and focal brain oxygenation in severely traumatized brain following direct regional brain hypothermia therapy: A prospective randomized study

    PubMed Central

    Idris, Zamzuri; Zenian, Mohd Sofan; Muzaimi, Mustapha; Hamid, Wan Zuraida Wan Abdul

    2014-01-01

    Background: Induced hypothermia for treatment of traumatic brain injury is controversial. Since many pathways involved in the pathophysiology of secondary brain injury are temperature dependent, regional brain hypothermia is thought capable to mitigate those processes. The objectives of this study are to assess the therapeutic effects and complications of regional brain cooling in severe head injury with Glasgow coma scale (GCS) 6-7. Materials and Methods: A prospective randomized controlled pilot study involving patients with severe traumatic brain injury with GCS 6 and 7 who required decompressive craniectomy. Patients were randomized into two groups: Cooling and no cooling. For the cooling group, analysis was made by dividing the group into mild and deep cooling. Brain was cooled by irrigating the brain continuously with cold Hartmann solution for 24-48 h. Main outcome assessments were a dichotomized Glasgow outcome score (GOS) at 6 months posttrauma. Results: A total of 32 patients were recruited. The cooling-treated patients did better than no cooling. There were 63.2% of patients in cooling group attained good GOS at 6 months compared to only 15.4% in noncooling group (P = 0.007). Interestingly, the analysis at 6 months post-trauma disclosed mild-cooling-treated patients did better than no cooling (70% vs. 15.4% attained good GOS, P = 0.013) and apparently, the deep-cooling-treated patients failed to be better than either no cooling (P = 0.074) or mild cooling group (P = 0.650). Conclusion: Data from this pilot study imply direct regional brain hypothermia appears safe, feasible and maybe beneficial in treating severely head-injured patients. PMID:25685201

  11. Liquid ventilator for ultrafast hypothermia induction in juvenile lambs: Preliminary results.

    PubMed

    Nadeau, Mathieu; Sage, Michaël; Kohlhauer, Matthias; Robert, Raymond; Vandamne, Jonathan; Mousseau, Julien; Tissier, Renaud; Praud, Jean-Paul; Walti, Hervé; Micheau, Philippe

    2015-08-01

    Total liquid ventilation (TLV) is an emerging mechanical ventilation technique. In this technique, the lungs are filled with liquid perfluorocarbons (PFC) and a liquid ventilator assures ventilation by periodically renewing a volume of oxygenated, CO2 freed and temperature controlled PFC. A huge difference between conventional mechanical ventilation and TLV relates to the fact that PFCs are about 1500 times denser than air. Thus, the PFCs filled lungs turn into an efficient heat exchanger with the circulating blood. One of the most appealing utilization of the lungs as a heat exchanger in TLV is for ultrafast induction of mild therapeutic hypothermia (MTH) for neuroprotection and cardioprotection after ischemia-reperfusion injuries. This study aimed to perform ultrafast MTH induction by TLV in animals up to 25 kg, then perform a fast post-hypothermic rewarming while maintaining proper ventilation. A thermal model of the lamb and liquid ventilator was developed to predict the dynamic and the control strategy to adopt for MTH induction. Two juvenile lambs were instrumented with temperature sensors in the femoral artery, pulmonary artery, oesophagus, right eardrum and rectum. After stabilization in conventional mechanical ventilation, TLV was initiated with ultrafast MTH induction, followed by posthypothermic rewarming. Preliminary results in the two juvenile lambs reveal that the liquid ventilator Inolivent-6.0 can induce MTH by TLV in less than 2.5 min for systemic arterial blood and in less than 10 min for venous return, esophagus and eardrum. Rectal temperature reached MTH in respectively 19.4 and 17.0 min for both lambs. Experimental results were consistent with the model predictions. Moreover, blood gas analysis exhibited that the gas exchange in the lungs was maintained adequately for the entire experiments.

  12. Therapeutic Hypothermia Protocol in a Community Emergency Department

    PubMed Central

    Kulstad, Christine E.; Holt, Shannon C.; Abrahamsen, Aaron A.; Lovell, Elise O.

    2010-01-01

    Objectives: Therapeutic hypothermia (TH) has been shown to improve survival and neurological outcome in patients resuscitated after out of hospital cardiac arrest (OHCA) from ventricular fibrillation/ventricular tachycardia (VF/VT). We evaluated the effects of using a TH protocol in a large community hospital emergency department (ED) for all patients with neurological impairment after resuscitated OHCA regardless of presenting rhythm. We hypothesized improved mortality and neurological outcomes without increased complication rates. Methods: Our TH protocol entails cooling to 33°C for 24 hours with an endovascular catheter. We studied patients treated with this protocol from November 2006 to November 2008. All non-pregnant, unresponsive adult patients resuscitated from any initial rhythm were included. Exclusion criteria were initial hypotension or temperature less than 30°C, trauma, primary intracranial event, and coagulopathy. Control patients treated during the 12 months before the institution of our TH protocol met the same inclusion and exclusion criteria. We recorded survival to hospital discharge, neurological status at discharge, and rates of bleeding, sepsis, pneumonia, renal failure, and dysrhythmias in the first 72 hours of treatment. Results: Mortality rates were 71.1% (95% CI, 56–86%) for 38 patients treated with TH and 72.3% (95% CI 59–86%) for 47 controls. In the TH group, 8% of patients (95% CI, 0–17%) had a good neurological outcome on discharge, compared to 0 (95% CI 0–8%) in the control group. In 17 patients with VF/VT treated with TH, mortality was 47% (95% CI 21–74%) and 18% (95% CI 0–38%) had good neurological outcome; in 9 control patients with VF/VT, mortality was 67% (95% CI 28–100%), and 0% (95% CI 0–30%) had good neurological outcome. The groups were well-matched with respect to sex and age. Complication rates were similar or favored the TH group. Conclusion: Instituting a TH protocol for OHCA patients with any

  13. Asystolic Cardiac Arrest of Unknown Duration in Profound Hypothermia and Polysubstance Overdose: A Case Report of Complete Recovery

    PubMed Central

    Lubana, Sandeep Singh; Genin, Dennis Iilya; Singh, Navdeep; De La Cruz, Angel

    2015-01-01

    Patient: Male, 20 Final Diagnosis: Asystolic cardiac arrest in profound hypothermia and poly-substance overdose Symptoms: Cardiac arrest • cardiac arrhythmia Medication: — Clinical Procedure: Endotracheal intubation • hemodialysis Specialty: Critical Care Medicine Objective: Unusual clinical course Background: Opioid addiction and overdose is a serious problem worldwide. Fatal overdoses from opioids are responsible for numerous deaths and are increasing, especially if taken in combination with other psychoactive substances. Combined with environmental exposure, opioid overdose can cause profound hypothermia. Opioid abuse and other drugs of abuse impair thermoregulation, leading to severe hypothermia. Both drug overdose and severe hypothermia can cause cardiac arrest. Case Report: We report a case of 20-year-old man with history of polysubstance abuse presenting with severe hypothermia and asystole of unknown duration with return of spontaneous circulation (ROSC) achieved after 28 minutes of cardiopulmonary resuscitation (CPR). Urine toxicology was positive for cocaine, heroin, and benzodiazepine, along with positive blood alcohol level. The patient was rewarmed using non-invasive techniques. Hospital course was complicated by acute renal failure (ARF), severe rhabdomyolysis, severe hyperkalemia, ST-elevation myocardial infarction (STEMI), shock liver, coagulopathy, and aspiration pneumonia. Conclusions: Survival with full cardiovascular and neurologic recovery after a cardiac arrest caused by drug overdose in the setting of severe hypothermia is still possible, even if the cardiac arrest is of unknown or prolonged duration. Patients with severe hypothermia experiencing cardiac arrest/hemodynamic instability can be rewarmed using non-invasive methods and may not necessarily need invasive rewarming techniques. PMID:26054008

  14. Deep hypothermia-enhanced autophagy protects PC12 cells against oxygen glucose deprivation via a mitochondrial pathway.

    PubMed

    Tang, Dang; Wang, Cheng; Gao, Yongjun; Pu, Jun; Long, Jiang; Xu, Wei

    2016-10-06

    Deep hypothermia is known for its organ-preservation properties, which is introduced into surgical operations on the brain and heart, providing both safety in stopping circulation as well as an attractive bloodless operative field. However, the molecular mechanisms have not been clearly identified. This study was undertaken to determine the influence of deep hypothermia on neural apoptosis and the potential mechanism of these effects in PC12 cells following oxygen-glucose deprivation. Deep hypothermia (18°C) was given to PC12 cells while the model of oxygen-glucose deprivation (OGD) induction for 1h. After 24h of reperfusion, the results showed that deep hypothermia decreased the neural apoptosis, and significantly suppressed overexpression of Bax, CytC, Caspase 3, Caspase 9 and cleaved PARP-1, and inhibited the reduction of Bcl-2 expression. While deep hypothermia increased the LC3II/LC3I and Beclin 1, an autophagy marker, which can be inhibited by 3-methyladenine (3-MA), indicating that deep hypothermia-enhanced autophagy ameliorated apoptotic cell death in PC12 cells subjected to OGD. Based on these findings we propose that deep hypothermia protects against neural apoptosis after the induction of OGD by attenuating the mitochondrial apoptosis pathway, moreover, the mechanism of these antiapoptosis effects is related to the enhancement of autophagy, which autophagy might provide a means of neuroprotection against OGD.

  15. Shapiro's syndrome: Defining the clinical spectrum of the spontaneous paroxysmal hypothermia syndrome.

    PubMed

    Tambasco, Nicola; Belcastro, Vincenzo; Prontera, Paolo; Nigro, Pasquale; Donti, Emilio; Rossi, Aroldo; Calabresi, Paolo

    2014-07-01

    Shapiro Syndrome (SS) is a rare condition of spontaneous periodic hypothermia, corpus callosum agenesis (ACC) and hyperhidrosis which can occur at any age. The variant form refers to the phenotypic SS without ACC. We reported the case of SS variant on a 4-year-old boy who presented from his first year frequent episodes of hypothermia lasting 2-3 h with core rectal temperatures <35 °C. In order to understand the characteristics of this rare syndrome we searched all the cases present in literature. Fifty-two cases of SS were found in literature. Among all clinical signs, paroxysmal hypothermia seems to be the hallmark of both typical and variant SS. ACC is reported only in 40% of cases of SS. Hyperhidrosis, another hallmark of SS, was present in only 42.3% of the cases and mainly in adult onset. The presence of SS in siblings of different genders suggests an autosomal recessive inheritance model, however a gonadic mosaicism responsible for an autosomal de novo mutation cannot be ruled out. From our review of well documented cases of SS, we conclude that only the episodic and spontaneous paroxysmal hypothermia should be considered the defining hallmark of typical and variant SS. This can be important to define the clinical manifestation of SS improving the early diagnosis.

  16. Medical instrument based on a heat pipe for local cavity hypothermia

    NASA Astrophysics Data System (ADS)

    Vasil'Ev, L. L.; Zhuraviyov, A. S.; Molodkin, F. F.; Khrolenok, V. V.; Zhdanov, V. L.; Vasil'Ev, V. L.; Adamov, S. I.; Tyurin, A. A.

    1996-05-01

    The design and results of tests of an instrument based on a heat pipe for local cavity hypothermia are presented. The instrument is a part of a device for noninvasive nonmedical treatment of inflammatory diseases of the organs of the small pelvis, pathologies of alimentary canal, etc.

  17. Changes in Surface Charge Density of Blood Cells in Fatal Accidental Hypothermia.

    PubMed

    Szeremeta, Michał; Petelska, Aneta Dorota; Kotyńska, Joanna; Pepiński, Witold; Naumowicz, Monika; Figaszewski, Zbigniew Artur; Niemcunowicz-Janica, Anna

    2015-12-01

    The objective of this research was to evaluate postmortem changes concerning electric charge of human erythrocytes and thrombocytes in fatal accidental hypothermia. The surface charge density values were determined on the basis of the electrophoretic mobility measurements of the cells conducted at various pH values of electrolyte solution. The surface charge of erythrocyte membranes after fatal accidental hypothermia increased compared to the control group within whole range of experimental pH values. Moreover, a slight shift of the isoelectric point of erythrocyte membranes towards high pH values was observed. The surface charge of thrombocyte membranes in fatal accidental hypothermia decreased at low pH compared to the control group. However, at pH range 4-9, the values increased compared to the control group. The isoelectric point of thrombocyte membranes after fatal accidental hypothermia was slightly shifted towards low pH values compared to the control group. The observed changes are probably connected with the partial destruction and functional changes of the blood cell structure.

  18. Thermal management during anaesthesia and thermoregulation standards for the prevention of inadvertent perioperative hypothermia.

    PubMed

    Torossian, Alexander

    2008-12-01

    Incidence of inadvertent perioperative hypothermia is still high, and thus thermoregulatory standards are warranted. This review summarizes current evidence of thermal management during anaesthesia, referring to recognized clinical queries (temperature measurement, definition of hypothermia, risk factors, warming methods, implementation strategies). Body temperature is a vital sign, and 37 degrees C is the mean core temperature of a healthy human. Systematic review shows that for non-invasive temperature monitoring the oral route is the most reliable; infrared ear temperature measurement is inaccurate. Intraoperatively, acceptable semi-invasive temperature monitoring sites are the nasopharynx, oesophagus and urinary bladder. Clinically relevant hypothermia starts at 36 degrees C with regard to major adverse outcomes (increased infectious complications, morbid cardiac events, coagulation disorders, prolonged length of hospital stay, and increased costs). Skin surface warming for 20 min immediately before anaesthesia (pre-warming) minimizes initial redistribution hypothermia. Intraoperatively, active warming should be applied when anaesthesia time is > 60 min. Effective methods of active warming are forced-air warming or conductive warming, provided that enough skin surface is available. Infusion fluid warming, increasing the operating room temperature, and warming of irrigation fluids are adjunctive therapies. The patient's body temperature should be above 36 degrees C before induction of anaesthesia, and should be measured continuously throughout surgery. Active warming should be applied intraoperatively. Postoperative patient temperature and outcomes should be evaluated.

  19. Shallow hypothermia depends on the level of fatty acid unsaturation in adipose and liver tissues in a tropical heterothermic primate.

    PubMed

    Vuarin, Pauline; Henry, Pierre-Yves; Guesnet, Philippe; Alessandri, Jean-Marc; Aujard, Fabienne; Perret, Martine; Pifferi, Fabien

    2014-07-01

    Optimal levels of unsaturated fatty acids have positive impacts on the use of prolonged bouts of hypothermia in mammalian hibernators, which generally have to face low winter ambient temperatures. Unsaturated fatty acids can maintain the fluidity of fat and membrane phospholipids at low body temperatures. However, less attention has been paid to their role in the regulation of shallow hypothermia, and in tropical species, which may be challenged more by seasonal energetic and/or water shortages than by low temperatures. The present study assessed the relationship between the fatty acids content of white adipose and liver tissues and the expression of shallow hypothermia in a tropical heterothermic primate, the gray mouse lemur (Microcebus murinus). The adipose tissue is the main tissue for fat storage and the liver is involved in lipid metabolism, so both tissues were expected to influence hypothermia dependence on fatty acids. As mouse lemurs largely avoid deep hypothermia (i.e. torpor) use under standard captive conditions, the expression of hypothermia was triggered by food-restricting experimental animals. Hypothermia depth increased with time, with a stronger increase for individuals that exhibited higher contents of unsaturated fatty acids suggesting that they were more flexible in their use of hypothermia. However these same animals delayed the use of long hypothermia bouts relative to individuals with a higher level of saturated fatty acids. This study evidences for the first time that body fatty acids unsaturation levels influence the regulation of body temperature not only in cold-exposed hibernators but also in tropical, facultative heterotherms.

  20. Perioperative hypothermia in NICU infants: its occurrence and impact on infant outcomes.

    PubMed

    Morehouse, Deborah; Williams, Lisa; Lloyd, Christina; McCoy, Dena S; Miller Walters, Elizabeth; Guzzetta, Cathie E; Baumgart, Stephen; Sill, Anne; Mueller-Burke, Dawn; Short, Billie Lou

    2014-06-01

    Infants admitted to the neonatal intensive care unit (NICU) often require surgical intervention and maintaining normothermia perioperatively is a major concern. In our preliminary study of 31 normothermic infants undergoing operative procedures in the operating room (OR), 58% (N = 18) returned hypothermic while all 5 undergoing procedures in the NICU remained normothermic (P = .001). To describe perioperative thermal instability (temperatures lower than 36.0°C) and frequency of associated adverse events, support interventions, and diagnostic tests in infants undergoing operative procedures in the OR and the NICU. This prospective, case-control study included 108 infants admitted to the NICU who were sequentially scheduled for an operative procedure in the OR (50.93%; N = 55) or the NICU (49.07%; N = 53). Existing data from the medical record were collected about temperatures and frequency of adverse cardiovascular, respiratory, and metabolic events, associated support interventions, and diagnostic tests during the perioperative period. Analyses examined the relative risks and proportional differences in rates of hypothermia between the OR group and the NICU group and associated adverse events, support interventions, and diagnostic tests between hypothermic and normothermic infants. Hypothermia developed in 40% (N = 43) of infants during the perioperative period. The OR group had a higher rate of perioperative hypothermia (65.45%, N = 36; P < .001) and were 7 times more likely to develop perioperative hypothermia (P = .008) than the NICU group (13.21%, N = 7). Likewise, infants in the OR group were 10 times more likely to develop hypothermia during the intra- and postoperative periods than those in the NICU group (P = .001). The hypothermic group had significantly more respiratory adverse events (P = .025), were 6 times more likely to require thermoregulatory interventions (P < .001), 5 times more likely to require cardiac support interventions (P < .006), and 3

  1. [Erythrocytes of hetero- and homoiothermal animals in natural and artificial hypothermia].

    PubMed

    Lomako, V V; Shilo, A V; Kovalenko, I F; Babiĭchuk, G A

    2015-01-01

    By the low-angle light scattering technique there are revealed peculiarities of dynamics of transformation (osmotic fragility, level of hemolysis and ratio of forms by index of sphericity) of erythrocytes of hetero- (golden hamsters Mesocricetus auratus) and homoiothermal (white rats Rattus norbegicus) animals in natural hibernation and suspended animation, craniocerebral and immersion hypothermia. In control in hamsters the osmotic fragility and the level of hemolysis of erythrocytes were higher than in rats, predominant were modified forms (in particular stomatocytes). Under artificial hypothermia, regardless of the way of achievement, depth and duration, we observed changes similar in direction, but different in expression: the osmotic fragility and hemolysis increased, the portion of discocytes decreased (especially sharply in hamsters under suspended animation), the number of changed erythrocytic forms rose. In contrast, under hiberation the osmotic fragility, hemolysis and the amount of stomatocytes declined, the portion of discocytes increased, but at the same time the amount of prehemolytic forms (spherocytes) rose too. In 24 hs there occurred a decrease of osmotic fragility (after suspended animation more pronounced in hamsters) and the level of hemolysis (especially after immersion hypothermia), the portion of discocytes was restored, in hamsters after suspended animation and in rats after immersion hypothermia it even exceeded the control level; spherocytes in blood of hamsters were not revealed, in rats they were elevated. Possibly, the observed qualitative change of population of spherocytes 24 h after hypothermia toward its homogeneity is determined not only at the level of elimination of old and defected cells, activation of erythropoiesis, the appearance of highly resistant erythrocytes, but also at the level of time membrane-stabilizing mechanisms.

  2. Comparison of 60-day mortality in hospitalized heart failure patients with versus without hypothermia.

    PubMed

    Payvar, Saeed; Orlandi, Cesare; Stough, Wendy Gattis; Elkayam, Uri; Ouyang, John; Casscells, S Ward; Gheorghiade, Mihai

    2006-12-01

    The use of aggressive treatments and the modification of current treatment in patients with heart failure (HF) relies heavily on the assessment of disease severity using prognostic markers. However, many such markers are unavailable in routine clinical practice, and others have little prognostic value. This study tested the hypothesis that low body temperature could predict short-term survival after discharge in patients hospitalized for HF. Data from the Acute and Chronic Therapeutic Impact of a Vasopressin Antagonist in Congestive Heart Failure (ACTIV in CHF) trial, which randomized 319 patients hospitalized for HF to receive placebo or tolvaptan, were retrospectively analyzed. Hypothermia was defined a priori as an oral body temperature <35.8 degrees C at randomization. Cox regression was used to analyze survival within a 60-day follow-up period. Hypothermia was observed in 32 patients (10%). Mortality rates at 60 days after discharge were 6.3% (20 of 319) overall, 9.4% (3 of 32) in hypothermic patients, and 5.9% (17 of 287) in nonhypothermic patients. Hypothermia was a strong multivariate predictor of mortality; hypothermic patients were 3.9 times more likely to die within 60 days than nonhypothermic patients (95% confidence interval 1.002 to 15.16, p = 0.0497) after adjustment for treatment group, age, and other confounders. Hypothermia was associated with such indicators of low cardiac output as an elevated blood urea nitrogen/creatinine ratio, narrow pulse pressure, and a reduced ejection fraction. In conclusion, hypothermia appears to be a strong predictor of mortality in patients with HF.

  3. [Characteristics of energy metabolism in the tissues of lake frogs and certain reptiles during prolonged deep hypothermia].

    PubMed

    L'vova, S P

    1981-01-01

    A week hypothermia (2-4 degrees C) does not cause a considerable decrease in content of glycogen in the liver, muscles, brain tissues of Lacerta strigata, Natrix tessellata and Rana ridibunda. In Eremias arguta pangolins the level of glycogen in the liver and muscles under these conditions is twice as low. Prolongation of hypothermia till three weeks causes a 4-fold decrease in the polysaccharide level in the liver of Eremias arguta and Lacerta strigata. The content of nonesterified fatty acids in blood under hypothermia (especially of three-week one) considerably exceeds the normal level. The content of lactic acid in tissues is two-three times as high under prolonged hypothermia, in the reptile muscles creatine phosphate accumulates in high amounts.

  4. White matter apoptosis is increased by delayed hypothermia and rewarming in a neonatal piglet model of hypoxic ischemic encephalopathy.

    PubMed

    Wang, B; Armstrong, J S; Reyes, M; Kulikowicz, E; Lee, J-H; Spicer, D; Bhalala, U; Yang, Z-J; Koehler, R C; Martin, L J; Lee, J K

    2016-03-01

    Therapeutic hypothermia is widely used to treat neonatal hypoxic ischemic (HI) brain injuries. However, potentially deleterious effects of delaying the induction of hypothermia and of rewarming on white matter injury remain unclear. We used a piglet model of HI to assess the effects of delayed hypothermia and rewarming on white matter apoptosis. Piglets underwent HI injury or sham surgery followed by normothermic or hypothermic recovery at 2h. Hypothermic groups were divided into those with no rewarming, slow rewarming at 0.5°C/h, or rapid rewarming at 4°C/h. Apoptotic cells in the subcortical white matter of the motor gyrus, corpus callosum, lateral olfactory tract, and internal capsule at 29h were identified morphologically and counted by hematoxylin & eosin staining. Cell death was verified by terminal deoxynucleotidyl transferase (TdT) dUTP nick end labeling (TUNEL) assay. White matter neurons were also counted, and apoptotic cells were immunophenotyped with the oligodendrocyte marker 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase). Hypothermia, slow rewarming, and rapid rewarming increased apoptosis in the subcortical white matter relative to normothermia (p<0.05). The number of white matter neurons was not lower in groups with more apoptosis after hypothermia or rapid rewarming, indicating that the apoptosis occurred among glial cells. Hypothermic piglets had more apoptosis in the lateral olfactory tract than those that were rewarmed (p<0.05). The promotion of apoptosis by hypothermia and rewarming in these regions was independent of HI. In the corpus callosum, HI piglets had more apoptosis than shams after normothermia, slow rewarming, and rapid rewarming (p<0.05). Many apoptotic cells were myelinating oligodendrocytes identified by CNPase positivity. Our results indicate that delaying the induction of hypothermia and rewarming are associated with white matter apoptosis in a piglet model of HI; in some regions these temperature effects are

  5. White matter apoptosis is increased by delayed hypothermia and rewarming in a neonatal piglet model of hypoxic ischemic encephalopathy

    PubMed Central

    Wang, Bing; Armstrong, Jillian S.; Reyes, Michael; Kulikowicz, Ewa; Lee, Jeong-Hoo; Spicer, Dawn; Bhalala, Utpal; Yang, Zeng-Jin; Koehler, Raymond C.; Martin, Lee J.; Lee, Jennifer K.

    2016-01-01

    Therapeutic hypothermia is widely used to treat neonatal hypoxic ischemic (HI) brain injuries. However, potentially deleterious effects of delaying the induction of hypothermia and of rewarming on white matter injury remain unclear. We used a piglet model of HI to assess the effects of delayed hypothermia and rewarming on white matter apoptosis. Piglets underwent HI injury or sham surgery followed by normothermic or hypothermic recovery at 2 h. Hypothermic groups were divided into those with no rewarming, slow rewarming at 0.5°C/h, or rapid rewarming at 4°C/h. Apoptotic cells in the subcortical white matter of the motor gyrus, corpus callosum, lateral olfactory tract, and internal capsule at 29 h were identified morphologically and counted by hematoxylin & eosin staining. Cell death was verified by TUNEL assay. White matter neurons were also counted, and apoptotic cells were immunophenotyped with the oligodendrocyte marker 2′,3′-cyclic-nucleotide 3′-phosphodiesterase (CNPase). Hypothermia, slow rewarming, and rapid rewarming increased apoptosis in the subcortical white matter relative to normothermia (p<0.05). The number of white matter neurons was not lower in groups with more apoptosis after hypothermia or rapid rewarming, indicating that the apoptosis occurred among glial cells. Hypothermic piglets had more apoptosis in the lateral olfactory tract than those that were rewarmed (p<0.05). The promotion of apoptosis by hypothermia and rewarming in these regions was independent of HI. In the corpus callosum, HI piglets had more apoptosis than shams after normothermia, slow rewarming, and rapid rewarming (p<0.05). Many apoptotic cells were myelinating oligodendrocytes identified by CNPase positivity. Our results indicate that delaying the induction of hypothermia and rewarming are associated with white matter apoptosis in a piglet model of HI; in some regions these temperature effects are independent of HI. Vulnerable cells include myelinating

  6. Problems and challenges in the early period of rehabilitating patients with severe hypothermia treated using ecmo support.

    PubMed

    Batycka-Stachnik, Dominika; Piwoda, Agnieszka; Darocha, Tomasz; Spiewak, Malgorzata; Kosinski, Sylweriusz; Jarosz, Anna; Hymczak, Hubert; Sanak, Tomasz; Galazkowski, Robert; Piatek, Jacek; Konstanty-Kalandyk, Janusz; Drwila, Rafal

    The objectives: To show and discuss the most frequent functional problems encountered in patients who underwent extracorporeal membrane oxygenation (ECMO) treatment after severe hypothermia and point out appropriate physiotherapy procedures used in order to diminish the effects of hypothermia on the human organism. It is necessary to look for effective physiotherapeutic solutions, especially that the number of scientific publications on the subject is very limited.

  7. An Experimental Study: Does the Neuroprotective Effect Increase When Hypothermia Deepens After Traumatic Brain Injury?

    PubMed Central

    Girisgin, Abdullah Sadik; Kalkan, Erdal; Ergin, Mehmet; Keskin, Fatih; Dundar, Zerrin Defne; Kebapcioglu, Sedat; Kocak, Sedat; Cander, Basar

    2015-01-01

    Background: Experimental approaches have been promising with the use of therapeutic hypothermia after Traumatic Brain Injury (TBI) whereas clinical data have not supported its efficacy. Objectives: This study aimed to investigate whether using selective deeper brain cooling correlates with a more neuroprotective effect on Intracranial Pressure (ICP) increments following TBI in rats. Materials and Methods: Adult male Sprague-Dawley rats (mean weight = 300 g; n = 25) were subjected to brain injury using a modified Marmarou method. Immediately after the onset of TBI, rats were randomized into three groups. Selective brain cooling was applied around the head using ice packages. Intracranial Temperature (ICT) and ICP were continuously measured at 0, 30, 60, 120, and 180 minutes and recorded for all groups. Group 1 (n = 5) was normothermia and was assigned as the control group. Group 2 (n = 10) received moderate hypothermia with a target ICT of between 32°C - 33°C and Group 3 (n = 10) was given a deeper hypothermia with a target ICT of below 32°C. Results: All subjects reached the target ICT by the 30th minute of hypothermia induction. The ICT was significantly different in Group 2 compared to Group 1 only at the 120th minute (P = 0.017), while ICP was significantly lower starting from the 30th minute (P = 0.015). The ICT was significantly lower in Group 3 compared to Groups 1 and 2 starting from the 30th minute (P = 0.001 and P = 0.003, respectively). The ICP was significantly lower in Group 3 compared to Group 1 starting from 30th minute (P = 0.001); however, a significant difference in ICP between Group 3 and Group 2 was observed only at the 180th minute (P = 0.047). Conclusions: Results of this study indicate that selective brain cooling is an effective method of decreasing ICP in rats; however, the deeper hypothermia caused a greater decrease in ICP three hours after hypothermia induction. PMID:26023335

  8. [Neuroprotection with hypothermia in the newborn with hypoxic-ischaemic encephalopathy. Standard guidelines for its clinical application].

    PubMed

    Blanco, D; García-Alix, A; Valverde, E; Tenorio, V; Vento, M; Cabañas, F

    2011-11-01

    Standardisation of hypothermia as a treatment for perinatal hypoxic-ischaemic encephalopathy is supported by current scientific evidence. The following document was prepared by the authors on request of the Spanish Society of Neonatology and is intended to be a guide for the proper implementation of this therapy. We discuss the difficulties that may arise when moving from the strict framework of clinical trials to clinical daily care: early recognition of clinical encephalopathy, inclusion and exclusion criteria, hypothermia during transport, type of hypothermia (selective head or systemic cooling) and side effects of therapy. The availability of hypothermia therapy has changed the prognosis of children with hypoxic-ischaemic encephalopathy and our choices of therapeutic support. In this sense, it is especially important to be aware of the changes in the predictive value of the neurological examination and the electroencephalographic recording in cooled infants. In order to improve neuroprotection with hypothermia we need earlier recognition of to recognise earlier the infants that may benefit from cooling. Biomarkers of brain injury could help us in the selection of these patients. Every single infant treated with hypothermia must be included in a follow up program in order to assess neurodevelopmental outcome.

  9. Fulminant form of acute disseminated encephalomyelitis in a child treated with mild hypothermia.

    PubMed

    Ichikawa, Kazushi; Motoi, Hirotaka; Oyama, Yoshitaka; Watanabe, Yoshihiro; Takeshita, Saoko

    2013-12-01

    We describe the case of a 3-year-old boy diagnosed with the fulminant form of acute disseminated encephalomyelitis (ADEM). He developed general fatigue, fever, drowsiness and difficulty in walking. He had extensive multiple high-intensity lesions in the white matter of the cerebrum and cerebellum, which are typical findings of ADEM. He became comatose and developed decerebrate rigidity with severe brain edema despite high-dose methylprednisolone therapy, and then was subjected to mild hypothermia therapy, and given i.v. immunoglobulin. The patient recovered remarkably with the sequela of only mild action tremor. The patient was considered to have acute hemorrhagic leukoencephalitis (AHLE), an extremely severe form of ADEM, in terms of the rapidly deteriorating clinical course and neuroimaging features. It was speculated that AHLE and ADEM might be a continuous disease spectrum. It is considered that the severe brain edema associated with ADEM or AHLE is a suitable indication for mild hypothermia therapy.

  10. Equipment to prevent, diagnose, and treat hypothermia: a survey of Norwegian pre-hospital services

    PubMed Central

    2013-01-01

    Introduction Hypothermia is associated with increased morbidity and mortality in trauma patients and poses a challenge in pre-hospital treatment. The aim of this study was to identify equipment to prevent, diagnose, and treat hypothermia in Norwegian pre-hospital services. Method In the period of April-August 2011, we conducted a survey of 42 respondents representing a total of 543 pre-hospital units, which included all the national ground ambulance services, the fixed wing and helicopter air ambulance service, and the national search and rescue service. The survey explored available insulation materials, active warming devices, and the presence of protocols describing wrapping methods, temperature monitoring, and the use of warm i.v. fluids. Results Throughout the services, hospital duvets, cotton blankets and plastic “bubble-wrap” were the most common insulation materials. Active warming devices were to a small degree available in vehicle ambulances (14%) and the fixed wing ambulance service (44%) but were more common in the helicopter services (58-70%). Suitable thermometers for diagnosing hypothermia were lacking in the vehicle ambulance services (12%). Protocols describing how to insulate patients were present for 73% of vehicle ambulances and 70% of Search and Rescue helicopters. The minority of Helicopter Emergency Medical Services (42%) and Fixed Wing (22%) units was reported to have such protocols. Conclusion The most common equipment types to treat and prevent hypothermia in Norwegian pre-hospital services are duvets, plastic “bubble wrap”, and cotton blankets. Active external heating devices and suitable thermometers are not available in most vehicle ambulance units. PMID:23938145

  11. Therapeutic hypothermia and reliability of somatosensory evoked potentials in predicting outcome after cardiopulmonary arrest.

    PubMed

    Rothstein, Ted Laurence

    2012-08-01

    The loss of the N20 component on testing median somatosensory evoked potentials (SSEP) has been established as the most reliable indicator of unfavorable prognosis in post-cardiopulmonary arrest patients. With the intervention of therapeutic hypothermia in the management of patients who remain comatose following cardiopulmonary arrest that association is now in dispute. Abandoning SSEP as a key prognostic indicator of neurologic outcome would be a serious loss and cannot be justified.

  12. Hypoxia, an adjunct in helium-cold hypothermia - Sparing effect on hepatic and cardiac metabolites.

    NASA Technical Reports Server (NTRS)

    Anderson, G. L.; Resch, G. E.; Musacchia, X. J.

    1973-01-01

    Investigation of the effect of hypoxia on the depletion of metabolites that occurs in helium-aided induction of hypothermia. Hypoxic slowing of the heart of a hamster while exposed to cold helox is demonstrated. An attempt is made to evaluate the relative importance of cardiac slowing and limitation of thermogenesis in determining the effect of hypoxia. In explanation of the results presented, it is suggested that hypoxia limits the energy expenditure by the heart during induction.

  13. ["TermoSpot" for the liquid-crystal indication of postoperative hypothermia in newborns].

    PubMed

    Chernyshev, A K

    2004-01-01

    Comparative prospective randomized measurements of body temperature were postoperatively made in 15 newborns by "Termospot", a new liquid-crystal temperature indicator. An analysis of 576 measuring examinations revealed a high-information density of the liquid-crystal cutaneous test (Se = 90.08; Pw = 0.98; Sp = 66.67). The subcutaneous liquid crystal "TermoSpot" temperature indicator could be an important tool in postoperative monitoring of hypothermia in newborn.

  14. Unilateral brain hypothermia as a method to examine efficacy and mechanisms of neuroprotection against global ischemia.

    PubMed

    Silasi, Gergely; Colbourne, Frederick

    2011-01-01

    Hypothermia, especially applied during ischemia, is the gold-standard neuroprotectant. When delayed, cooling must often be maintained for a day or more to achieve robust, permanent protection. Most animal and clinical studies use whole-body cooling-an arduous technique that can cause systemic complications. Brain-selective cooling may avoid such problems. Thus, in this rat study, we used a method that cools one hemisphere without affecting the contralateral side or the body. Localized brain hypothermia was achieved by flushing cold water through a metal tube attached to the rats' skull. First, in anesthetized rats we measured temperature in the cooled and contralateral hemisphere to demonstrate selective unilateral cooling. Subsequent telemetry recordings in awake rats confirmed that brain cooling did not cause systemic hypothermia during prolonged treatment. Additionally, we subjected rats to transient global ischemia and after recovering from anesthesia they remained at normothermia or had their right hemisphere cooled for 2 days (∼32°C-33°C). Hypothermia significantly lessened CA1 injury and microglia activation on the right side at 1 and 4 week survival times. Near-complete injury and a strong microglia response occurred in the left (normothermic) hippocampus as occurred in both hippocampi of the untreated group. Thus, this focal cooling method is suitable for evaluating the efficacy and mechanisms of hypothermic neuroprotection in global ischemia models. This method also has advantages over many current systemic cooling protocols in rodents, namely: (1) lower cost, (2) simplicity, (3) safety and suitability for long-term cooling, and (4) an internal control-the normothermic hemisphere.

  15. The Effects of Hypothermia on Fibrinogen Metabolism and Coagulation Function in Swine

    DTIC Science & Technology

    2007-01-01

    Continuous arteriovenous rewarming: experimental results and thermodynamic model simula- tion of treatment for hypothermia. J Trauma 1990;30:1436-49. [6...of fibrinogen in cirrhosis of the liver. J Clin Invest 1971;50:1690-701. [22] Rand MD, Lock JB, van’t Veer C, et al. Blood clotting in minimally...fibrinogen synthesis in hemodialysis patients with normal nutritional status. J Am Soc Nephrol 2001;12: 349 -54. [36] Olsen AK. The pig as a model in

  16. Radioprotection in depressed metabolic states: The physiology of helium-cold hypothermia

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.

    1973-01-01

    The use of hypothermia as a means of radiation protection was studied on a variety of mammals exposed to 80% helium-20% oxygen atmospheres at low ambient temperatures. Results show that the LD for normothermic animals significantly increased compared with hypothermic animals; similar results were obtained for hibernating mammalians. Pre-exposure of animals to cold temperatures increased their ability to withstand radiation levels close to LD sub 50.

  17. Extended Use of Hypothermia in Elderly Patients with Malignant Cerebral Edema as an Alternative to Hemicraniectomy

    PubMed Central

    Jeong, Han-Yeong; Chang, Jun-Young; Yum, Kyu Sun; Hong, Jeong-Ho; Jeong, Jin-Heon; Yeo, Min-Ju; Bae, Hee-Joon; Han, Moon-Ku; Lee, Kiwon

    2016-01-01

    Background and Purpose The use of decompressive hemicraniectomy (DHC) for the treatment of malignant cerebral edema can decrease mortality rates. However, this benefit is not sufficient to justify its use in elderly patients. We investigated the effects of therapeutic hypothermia (TH) on safety, feasibility, and functional outcomes in elderly patients with malignant middle cerebral artery (MCA) infarcts. Methods Elderly patients 60 years of age and older with infarcts affecting more than two-thirds of the MCA territory were included. Patients who could not receive DHC were treated with TH. Hypothermia was started within 72 hours of symptom onset and was maintained for a minimum of 72 hours with a target temperature of 33°C. Modified Rankin Scale (mRS) scores at 3 months following treatment and complications of TH were used as functional outcomes. Results Eleven patients with a median age of 76 years and a median National Institutes of Health Stroke Scale score of 18 were treated with TH. The median time from symptom onset to initiation of TH was 30.3±23.0 hours and TH was maintained for a median of 76.7±57.1 hours. Shivering (100%) and electrolyte imbalance (82%) were frequent complications. Two patients died (18%). The mean mRS score 3 months following treatment was 4.9±0.8. Conclusions Our results suggest that extended use of hypothermia is safe and feasible for elderly patients with large hemispheric infarctions. Hypothermia may be considered as a therapeutic alternative to DHC in elderly individuals. Further studies are required to validate our findings. PMID:27488978

  18. Provision of Therapeutic Hypothermia in Neonatal Transport: A Longitudinal Study and Review of Literature

    PubMed Central

    2015-01-01

    Background: Worldwide, a significant proportion of infants needing therapeutic hypothermia for hypoxia-ischaemia are transported to a higher-level facility for neonatal intensive care. They pose technical challenges to transport teams in cooling them. Concerns exist about the efficacy of passive cooling in neonatal transport to achieve a neurotherapeutic temprature. Servo-controlled cooling in the standard of care on the neonatal unit. The key question is whether the same standard of care in the neonatal unit can be safely used for therapeutic hypothermia during transport of neonates with suspected hypoxia-ischaemia. Methods: A prospective cross-sectional survey of United Kingdom (UK) neonatal transport services (n=21) was performed annually from 2011-2014 with a 100% response. The survey ascertained information about service provision and the method of cooling used during transport. Results: In 2011, all UK neonatal transport services provided therapeutic hypothermia during transport. Servo-control cooling machines were used by only 6 of the 21 teams (30%) while passive cooling was used by 15 of the 21 (70%) teams. In 2012 9 of the 21 teams (43%) were using servo-control. By 2014 the number of teams using servo-control cooling had more than doubled to 15 of the 21 (62%) services. Teams have done this through modification of transport trolleys and dedicated ambulances. Conclusion: Servo-controlled cooling in neonatal transport is becoming more common in the UK. The question remains whether it should be endorsed as a standard of care. Some teams continue to passively cool neonates with hypoxia-ischaemia during transport. This article reviews the drivers, current evidence, safety and processes involved in provision of therapeutic hypothermia during neonatal transport to enable teams to decide what would be the right option for them. PMID:26180694

  19. Effects of Hypothermia and Self-Warming on Activity of Ca(2+)-Dependent Neutral Proteases in Tissues of Ground Squirrels and Rats.

    PubMed

    Nurmagomedova, P M; Emirbekov, E Z; Abasova, M M

    2016-04-01

    Effects of hypothermia and subsequent self-warming on activity of Ca(2+)-dependent neutral proteases were studied in tissues of ground squirrels and rats. Moderate hypothermia did not significantly change activity of Ca(2+)-dependent neutral proteases in the analyzed tissues of ground squirrels, but reduced protease activity in rat heart. Severe hypothermia reduced enzyme activity in the analyzed tissues of rats and ground squirrels. Differences in activity of Ca(2+)-dependent neutral proteases after long-term hypothermia and subsequent self-warming were found only in the heart.

  20. Potential role of the gut microbiota in synthetic torpor and therapeutic hypothermia

    PubMed Central

    Sisa, Claudia; Turroni, Silvia; Amici, Roberto; Brigidi, Patrizia; Candela, Marco; Cerri, Matteo

    2017-01-01

    Therapeutic hypothermia is today used in several clinical settings, among them the gut related diseases that are influenced by ischemia/reperfusion injury. This perspective paved the way to the study of hibernation physiology, in natural hibernators, highlighting an unexpected importance of the gut microbial ecosystem in hibernation and torpor. In natural hibernators, intestinal microbes adaptively reorganize their structural configuration during torpor, and maintain a mutualistic configuration regardless of long periods of fasting and cold temperatures. This allows the gut microbiome to provide the host with metabolites, which are essential to keep the host immunological and metabolic homeostasis during hibernation. The emerging role of the gut microbiota in the hibernation process suggests the importance of maintaining a mutualistic gut microbiota configuration in the application of therapeutic hypothermia as well as in the development of new strategy such as the use of synthetic torpor in humans. The possible utilization of tailored probiotics to mold the gut ecosystem during therapeutic hypothermia can also be taken into consideration as new therapeutic strategy. PMID:28210076

  1. Potential role of the gut microbiota in synthetic torpor and therapeutic hypothermia.

    PubMed

    Sisa, Claudia; Turroni, Silvia; Amici, Roberto; Brigidi, Patrizia; Candela, Marco; Cerri, Matteo

    2017-01-21

    Therapeutic hypothermia is today used in several clinical settings, among them the gut related diseases that are influenced by ischemia/reperfusion injury. This perspective paved the way to the study of hibernation physiology, in natural hibernators, highlighting an unexpected importance of the gut microbial ecosystem in hibernation and torpor. In natural hibernators, intestinal microbes adaptively reorganize their structural configuration during torpor, and maintain a mutualistic configuration regardless of long periods of fasting and cold temperatures. This allows the gut microbiome to provide the host with metabolites, which are essential to keep the host immunological and metabolic homeostasis during hibernation. The emerging role of the gut microbiota in the hibernation process suggests the importance of maintaining a mutualistic gut microbiota configuration in the application of therapeutic hypothermia as well as in the development of new strategy such as the use of synthetic torpor in humans. The possible utilization of tailored probiotics to mold the gut ecosystem during therapeutic hypothermia can also be taken into consideration as new therapeutic strategy.

  2. 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.

  3. [Effect of very early kangaroo care on extrauterine temperature adaptation in newborn infants with hypothermia problems].

    PubMed

    Huang, Ya-Yi; Huang, Ching-Yi; Lin, Shiu-Mei; Wu, Shu-Chuan

    2006-08-01

    Increased morbidity and mortality has been associated with neonates admitted with body temperatures below 36 degrees C. We employed an experimental design in a randomized control trial to compare the effectiveness of using early kangaroo care (KC) for extrauterine temperature adaptation against that of using radiant warmers. Trial subjects included 78 consecutive cesarean newborn infants with hypothermia problems. The KC group received skin-to-skin contact with their mothers in the post-operative room, while infants in the control group received routine care under radiant warmers. The mean temperature of the KC group was slightly higher than that of the control group (36.29 degrees C vs. 36.22 degrees C, p = .044). After four hours, 97.43% of KC group infants had reached normal body temperatures, compared with 82.05% in the radiant warmer group. Results demonstrate the positive effects of KC for extrauterine temperature adaptation in hypothermia infants. In the course of evidence-based practice, KC could be incorporated into the standard care regimen in order to improve hypothermia care.

  4. Use of a nursing checklist to facilitate implementation of therapeutic hypothermia after cardiac arrest.

    PubMed

    Avery, Kathleen Ryan; O'Brien, Molly; Pierce, Carol Daddio; Gazarian, Priscilla K

    2015-02-01

    Therapeutic hypothermia has become a widely accepted intervention that is improving neurological outcomes following return of spontaneous circulation after cardiac arrest. This intervention is highly complex but infrequently used, and prompt implementation of the many steps involved, especially achieving the target body temperature, can be difficult. A checklist was introduced to guide nurses in implementing the therapeutic hypothermia protocol during the different phases of the intervention (initiation, maintenance, rewarming, and normothermia) in an intensive care unit. An interprofessional committee began by developing the protocol, a template for an order set, and a shivering algorithm. At first, implementation of the protocol was inconsistent, and a lack of clarity and urgency in managing patients during the different phases of the protocol was apparent. The nursing checklist has provided all of the intensive care nurses with an easy-to-follow reference to facilitate compliance with the required steps in the protocol for therapeutic hypothermia. Observations of practice and feedback from nursing staff in all units confirm the utility of the checklist. Use of the checklist has helped reduce the time from admission to the unit to reaching the target temperature and the time from admission to continuous electroencephalographic monitoring in the cardiac intensive care unit. Evaluation of patients' outcomes as related to compliance with the protocol interventions is ongoing.

  5. Hypothermia Increases Tissue Plasminogen Activator Expression and Decreases Post-Operative Intra-Abdominal Adhesion

    PubMed Central

    Lee, Chien-Chang; Wang, Hsuan-Mao; Chou, Tzung-Hsin; Wu, Meng-Che; Hsueh, Kuang-Lung; Chen, Shyr-Chyr

    2016-01-01

    Background Therapeutic hypothermia during operation decreases postoperative intra-abdominal adhesion formation. We sought to determine the most appropriate duration of hypothermia, and whether hypothermia affects the expression of tissue plasminogen activator (tPA). Methods 80 male BALB/c mice weighing 25–30 g are randomized into one of five groups: adhesion model with infusion of 15°C saline for 15 minutes (A); 30 minutes (B); 45 minute (C); adhesion model without infusion of cold saline (D); and sham operation without infusion of cold saline (E). Adhesion scores and tPA levels in the peritoneum fluid levels were analyzed on postoperative days 1, 7, and 14. Results On day 14, the cold saline infusion groups (A, B, and C) had lower adhesion scores than the without infusion of cold saline group (D). However, only group B (cold saline infusion for 30 minutes) had a significantly lower adhesion scores than group D. Also, group B was found to have 3.4 fold, 2.3 fold, and 2.2 fold higher levels of tPA than group D on days 1, 7, and 14 respectively. Conclusions Our results suggest that cold saline infusion for 30 minutes was the optimum duration to decrease postoperative intra-abdominal adhesion formation. The decrease in the adhesion formations could be partly due to an increase in the level of tPA. PMID:27583464

  6. Patterns and dynamics of rest-phase hypothermia in wild and captive blue tits during winter.

    PubMed

    Nord, Andreas; Nilsson, Johan F; Sandell, Maria I; Nilsson, Jan-Ake

    2009-08-01

    We evaluated biotic and abiotic predictors of rest-phase hypothermia in wintering blue tits (Cyanistes caeruleus) and also assessed how food availability influences nightly thermoregulation. On any given night, captive blue tits (with unrestricted access to food) remained largely homeothermic, whereas free-ranging birds decreased their body temperature (T(b)) by about 5 degrees C. This was not an effect of increased stress in the aviary as we found no difference in circulating corticosterone between groups. Nocturnal T(b) in free-ranging birds varied with ambient temperature, date and time. Conversely, T(b) in captive birds could not be explained by climatic or temporal factors, but differed slightly between the sexes. We argue that the degree of hypothermia is controlled predominantly by birds' ability to obtain sufficient energy reserves during the day. However, environmental factors became increasingly important for thermoregulation when resources were limited. Moreover, as birds did not enter hypothermia in captivity when food was abundant, we suggest that this strategy has associated costs and hence is avoided whenever resource levels permit.

  7. Heart rate variability and electrocardiogram waveform as predictors of morbidity during hypothermia and rewarming in rats.

    PubMed

    Matthew, C B; Bastille, A M; Gonzalez, R R; Sils, I V

    2002-09-01

    This study examined electrocardiogram (ECG) waveform, heart rate (HR), mean blood pressure (BP), and HR variability as potential autonomic signatures of hypothermia and rewarming. Adult male Sprague-Dawley rats had telemetry transmitters surgically implanted, and 2 weeks were allowed for recovery prior to induction of hypothermia. Rats were lightly anesthetized (sodium pentobarbital, 35 mg/kg i.p.) and placed in a coil of copper tubing through which temperature-controlled water was circulated. Animals were cooled to a core temperature (Tc) of 20 degrees C, maintained there for 30 min, and then rewarmed. Data (Tc, BP, HR from ECG, and 10-s strips of ECG waveforms) were collected every 5 min throughout hypothermia and rewarming. Both HR and BP declined after initial increases with the drop in HR starting at a higher Tc than the drop in BP (29.6 +/- 2.4 degrees C vs. 27.1 +/- 3.3 degrees C, p < 0.05). Animals that were not successfully rewarmed exhibited a significant (p < 0.05) increase in the normalized standard deviation of interbeat intervals (IBI) throughout cooling compared with animals that were successfully rewarmed. The T wave of the ECG increased in amplitude and area with decreasing Tc. T-wave amplitude and IBI variability show potential as predictors of survival in hypothermic victims.

  8. Proposed guidelines for skin-to-skin treatment of neonatal hypothermia.

    PubMed

    Galligan, Maura

    2006-01-01

    Hypothermia is not uncommon in full-term, low-risk newborns during the first days of life. Standard care for treating hypothermia often involves the separation of the mother and the newborn while the infant is placed under a warmer and observed in the nursery. Because one important role of the postpartum nurse is to promote mother-infant attachment by encouraging the mother to spend time "getting to know" her infant, this separation can be problematic. This article proposes that skin-to-skin (STS) care, also called kangaroo care, an intervention in which the unclothed, diapered infant is placed on the mother's bare chest, be used to promote thermoregulation instead of using separation and a warmer. STS care has been recognized as a way to facilitate maternal-infant attachment and promote thermoregulation. The literature review here provides an analysis of the available evidence and the author's conclusion that the research supports the use of STS care as an alternative to traditional rewarming. The evidence was graded and organized into an evidence-based practice guideline for the use of STS care in the treatment of mild hypothermia in the low-risk infant. Suggestions for further research and outcomes measurement are included.

  9. Changes in hippocampal ultrastructure and vimentin expression in rhesus monkeys following selective deep hypothermia and blood occlusion.

    PubMed

    Li, B C; Fu, X; Niu, X Q; Fan, Y D; Xu, W; Zhao, X X; Pu, J

    2015-01-30

    Previous studies have shown that selective cerebral profound hypothermia combined with antegrade cerebral perfusion can improve resistance to cerebral hypoxia-ischemia in monkeys. The aim of this study was to observe the effect of selective cerebral profound hypothermia on the ultrastructure and vimentin expression in monkey hippocampi after severe cerebral ischemia. Eight healthy adult rhesus monkeys were randomly divided into two groups: profound hypothermia (N = 5) and normothermia (N = 3). Monkeys in the profound hypothermia group underwent bilateral carotid artery and jugular vein occlusion for 10 minutes at room temperature. Ringer's solution at 4°C was then perfused through the right internal carotid artery and out of the right jugular vein, maintaining the brain temperature below 18°C. Sixty minutes later, cerebral blood flow was restored. The normothermia group underwent all procedures with the exception that the Ringer's solution was 37°C during perfusion. All animals in the profound hypothermia group were successfully resuscitated. No significant abnormalities of hippocampal morphology or ultrastructure were observed. In contrast, no monkeys were alive after perfusion in the normothermia group and they had abnormal hippocampal morphology and ultrastructure to different extents. Vimentin expression in the hippocampus was significantly lower in the profound hypothermia group (47.88% ± 1.66) than the normothermia group (79.51% ± 1.00; P < 0.01). We conclude that selective cerebral profound hypothermia following 10-min occlusion of the bilateral common carotid arteries was able to downregulate vimentin expression in the hippocampus and protect it from severe cerebral ischemia.

  10. Additive neuroprotection of a 20-HETE inhibitor with delayed therapeutic hypothermia after hypoxia-ischemia in neonatal piglets

    PubMed Central

    Zhu, Junchao; Wang, Bing; Lee, Jeong-Hoo; Armstrong, Jillian S.; Kulikowicz, Ewa; Bhalala, Utpal S.; Martin, Lee J.; Koehler, Raymond C.; Yang, Zeng-Jin

    2015-01-01

    The severity of perinatal hypoxia-ischemia and the delay in initiating therapeutic hypothermia limit the efficacy of hypothermia. After hypoxia-ischemia in neonatal piglets, the arachidonic acid metabolite, 20-hydroxyeicosatetraenoic acid (20-HETE), has been found to contribute to oxidative stress at 3 hours of reoxygenation and to eventual neurodegeneration. We tested whether early administration of a 20-HETE-synthesis inhibitor after reoxygenation augments neuroprotection with 3-hour delayed hypothermia. In two hypothermic groups, whole body cooling from 38.5 to 34°C was initiated 3 hours after hypoxia-ischemia. Rewarming occurred from 20 to 24 hours; then anesthesia was discontinued. One hypothermic group received a 20-HETE inhibitor at 5 minutes after reoxygenation. A sham-operated group and another hypoxia-ischemia group remained normothermic. At 10 days of recovery, resuscitated piglets with delayed hypothermia alone had significantly greater viable neuronal density in putamen, caudate nucleus, sensorimotor cortex, CA3 hippocampus, and thalamus than did piglets with normothermic recovery, but the values remained less than those in the sham-operated group. In piglets administered the 20-HETE inhibitor before hypothermia, the density of viable neurons in putamen, cortex, and thalamus was significantly greater than in the group with hypothermia alone. Cytochrome P450 4A, which can synthesize 20-HETE, was expressed in piglet neurons in these regions. We conclude that early treatment with a 20-HETE inhibitor enhances the therapeutic benefit of delayed hypothermia in protecting neurons in brain regions known to be particularly vulnerable to hypoxia-ischemia in term newborns. PMID:25721266

  11. Multimodel quantitative analysis of somatosensory evoked potentials after cardiac arrest with graded hypothermia.

    PubMed

    Leanne Moon Young; Choudhary, Rishabh; Xiaofeng Jia

    2016-08-01

    Cardiac arrest (CA) is one of the most prominent causes of morbidity and mortality in adults. Therapeutic hypothermia (TH) is a recommended treatment to improve survival and functional outcome following CA, however, it is unclear what degree of TH is most beneficial. It has been suggested that TH of 33°C provides no survival or outcome benefits over TH of 36°C. Additionally, there is a lack of verified objective quantitative prognostic tools for comatose CA patients under TH. In this study, we calculated three quantitative markers of somatosensory evoked potentials (SSEP) to examine their potential to track recovery in the early period following CA under graded TH. A total of 16 rats were randomly divided among 4 temperature groups (n=4/group): normothermia (N0, 36.5-37.5°C), hypothermia 1 (H1, 30-32°C), hypothermia 2 (H2, 32-34°C) and hypothermia 3 (H3, 34-36°C). All rats underwent a 15min baseline SSEP recording followed by 9min asphyxial-CA, resulting in severe cerebral injury, and immediate temperature management following resuscitation for 6 hours. SSEP recordings were maintained in 15 min intervals from 30min-4hrs after resuscitation. The N10 amplitude, N10 latency and quantitative SSEP phase space area (qSSEP-PSA) were calculated for the early recovery period and normalized to their respective baselines. Functional recovery was determined by the neurological deficit scale (NDS). N10 amplitude was significantly larger in H1, H2 and H3 compared to N0. N10 latency was significantly longer in H1 than all temperature groups and all hypothermia groups had significantly longer latencies than N0. qSSEP-PSA had significantly better recovery in H1 and H2 than N0. Animals with good outcome (72hr NDS>50) had better recovery of all markers. N10 amplitude was significantly correlated with N10 latency and qSSEP-PSA. The results importantly demonstrate that quantified SSEPs have the potential to objectively track recovery following CA with graded TH.

  12. SBDPs and Tau proteins for diagnosis and hypothermia therapy in neonatal hypoxic ischemic encephalopathy

    PubMed Central

    Wu, Hongwei; Li, Zhenguang; Yang, Xia; Liu, Jinfeng; Wang, Wei; Liu, Gang

    2017-01-01

    The use of spectrin breakdown products (SBDPs) and Tau protein levels for diagnosis and a mild hypothermia therapy for treatment of neonatal hypoxic-ischemic encephalopathy (HIE) was evaluated. One hundred and fifty infants, with HIE within 12 h after birth, participated in the study. There were 30 newborns with mild symptoms, 60 with moderate symptoms, 60 with severe symptoms, and 30 in a control group. Regular therapy was used for the control and the mild HIE groups, and also for 30 cases in the group with moderate symptoms and for 30 in the group with severe symptoms. For the remaining infants, with moderate and severe symptoms, mild hypothermia therapy was used instead. A sandwich ELISA measured plasma concentrations of SBDPs and Tau proteins, at different time-points. For clinical follow-up, the neonatal behavioral neurological assessment (NBNA) assay and the Gesell development scale were performed at different time-points. The levels of SBDP and Tau proteins increased with the exacerbation of HIE, and decreased with the prolongation of therapy with statistically significant differences amongst groups. After treatment, the levels of SBDP and Tau proteins in groups with moderate and severe symptoms treated with mild hypothermia therapy were significantly lower than those of the groups treated with regular therapy. NBNA scores and the developmental quotient (DQ) were both worse with the increase in severity of HIE, however, the scores of groups with moderate and severe symptoms treated with mild hypothermia therapy were significantly better than those of groups treated with regular therapy (P<0.05). A gradual improvement of DQ was seen in the process of therapy in each group (P<0.05). According to a receiver operating characteristic (ROC) curve analysis, at a critical plasma concentration of SBDPs of 1.58 ng/ml, the sensitivity and specificity for HIE diagnosis was 84.6 and 87.5%, respectively. The ROC analysis for Tau protein yielded a sensitivity and

  13. Therapeutic Hypothermia after Out-of-Hospital Cardiac Arrest in Children

    PubMed Central

    Moler, Frank W.; Silverstein, Faye S.; Holubkov, Richard; Slomine, Beth S.; Christensen, James R.; Nadkarni, Vinay M.; Meert, Kathleen L.; Clark, Amy E.; Browning, Brittan; Pemberton, Victoria L.; Page, Kent; Shankaran, Seetha; Hutchison, Jamie S.; Newth, Christopher J.L.; Bennett, Kimberly S.; Berger, John T.; Topjian, Alexis; Pineda, Jose A.; Koch, Joshua D.; Schleien, Charles L.; Dalton, Heidi J.; Ofori-Amanfo, George; Goodman, Denise M.; Fink, Ericka L.; McQuillen, Patrick; Zimmerman, Jerry J.; Thomas, Neal J.; van der Jagt, Elise W.; Porter, Melissa B.; Meyer, Michael T.; Harrison, Rick; Pham, Nga; Schwarz, Adam J.; Nowak, Jeffrey E.; Alten, Jeffrey; Wheeler, Derek S.; Bhalala, Utpal S.; Lidsky, Karen; Lloyd, Eric; Mathur, Mudit; Shah, Samir; Wu, Theodore; Theodorou, Andreas A.; Sanders, Ronald C.; Dean, J. Michael

    2015-01-01

    Background Therapeutic hypothermia is recommended for comatose adults after witnessed out-of-hospital cardiac arrest, but data about this intervention in children are limited. Methods We conducted this trial of two targeted temperature interventions at 38 children’s hospitals involving children who remained unconscious after out-of-hospital cardiac arrest. Within 6 hours after the return of circulation, comatose patients who were older than 2 days and younger than 18 years of age were randomly assigned to therapeutic hypothermia (target temperature, 33.0°C) or therapeutic normothermia (target temperature, 36.8°C). The primary efficacy outcome, survival at 12 months after cardiac arrest with a Vineland Adaptive Behavior Scales, second edition (VABS-II), score of 70 or higher (on a scale from 20 to 160, with higher scores indicating better function), was evaluated among patients with a VABS-II score of at least 70 before cardiac arrest. Results A total of 295 patients underwent randomization. Among the 260 patients with data that could be evaluated and who had a VABS-II score of at least 70 before cardiac arrest, there was no significant difference in the primary outcome between the hypothermia group and the normothermia group (20% vs. 12%; relative likelihood, 1.54; 95% confidence interval [CI], 0.86 to 2.76; P = 0.14). Among all the patients with data that could be evaluated, the change in the VABS-II score from baseline to 12 months was not significantly different (P = 0.13) and 1-year survival was similar (38% in the hypothermia group vs. 29% in the normothermia group; relative likelihood, 1.29; 95% CI, 0.93 to 1.79; P = 0.13). The groups had similar incidences of infection and serious arrhythmias, as well as similar use of blood products and 28-day mortality. Conclusions In comatose children who survived out-of-hospital cardiac arrest, therapeutic hypothermia, as compared with therapeutic normothermia, did not confer a significant benefit in survival with a

  14. In vivo effects of 3-iodocytisine: pharmacological and genetic analysis of hypothermia and evaluation of chronic treatment on nicotinic binding sites.

    PubMed

    Zambrano, C A; Marks, M J; Cassels, B K; Maccioni, R B

    2009-09-01

    Several cytisine derivatives have been developed in the search for more selective drugs at nicotinic acetylcholine receptors (nAChR). Binding experiments in transfected cell lines showed that the iodination of cytisine in the position 3 of the pyridone ring increased potency at alpha7-nAChR and to a lesser extent at the alpha4beta2 subtypes, both of which are widely expressed in the brain. However, no in vivo studies have been published on this compound. Inhibition curves presented here using wild type, beta2, and beta4-null mutant mice confirm that 3-IC binds to alpha4beta2 *, alpha7 * and alpha3beta4 * receptors with higher affinity than cytisine (asterisk indicates the receptor may contain additional subunits, Lukas et al., 1999). Intraperitoneal injection of 3-iodocytisine (3-IC) induced considerable dose-dependent hypothermia in DBA/2J and C57BL/6J mice. This response was blocked by mecamylamine and partially inhibited by hexamethonium. beta4-null mice displayed significantly less 3-IC-induced hypothermia than wild-type mice, beta2-null mice were somewhat less affected than wild types, while responses of alpha7 *-null mice were similar to wild types. Mice treated chronically with 3-IC display a marked increase in alpha7 * and alpha4beta2 * binding sites determined by radioligand binding in membrane preparations from cerebral cortex and hippocampus. Quantitative autoradiographic analysis of 28 brain regions of mice treated with 3-IC was consistent with the membrane binding, detecting an increase of cytisine-sensitive [(125)I]epibatidine binding sites, while cytisine-resistant [(125)I]epibatidine sites were unchanged. [(125)I]alpha-Bungarotoxin binding sites also exhibited up-regulation. These results give a first evaluation of in vivo consequences of 3-IC as a potent agonist with marked effects on mice.

  15. Whole body hypothermia broadens the therapeutic window of intranasally administered IGF-1 in a neonatal rat model of cerebral hypoxia-ischemia

    PubMed Central

    Lin, Shuying; Rhodes, Philip G.; Cai, Zhengwei

    2011-01-01

    To investigate whether whole body hypothermia after neonatal cerebral hypoxia-ischemia (HI) could broaden the therapeutic window of intranasal treatment of IGF-1 (iN-IGF-1), postnatal day 7 rat pups were subjected to right common carotid artery ligation, followed by 8% oxygen inhalation for 2 h. After HI, one group of pups were returned to their dams and kept at room temperature (24.5±0.2°C). A second group of pups were subjected to whole body hypothermia in a cool environment (21.5±0.3°C) for 2 or 4 h before being returned to their dams. Two doses of 50 μg recombinant human IGF-1 were administered intranasally at a 1 h interval starting at 0, 2 or 4 h after hypothermia. Hypothermia decreased the rectal temperature of pups by 4.5°C as compared to those kept at room temperature. While hypothermia or iN-IGF-1 administered 2 h after HI alone did not provide neuroprotection, the combined treatment of hypothermia with iN-IGF-1 significantly protected the neonatal rat brain from HI injury. Hypothermia treatment extended the therapeutic window of IGF-1 to 6 h after HI. The extended IGF-1 therapeutic window by hypothermia was associated with decreases in infiltration of polymorphonuclear leukocytes and activation of microglia/macrophages and with attenuation of NF-κB activation in the ipsilateral hemisphere following HI. PMID:21316352

  16. Moderate Hypothermia Provides Better Protection of the Intestinal Barrier than Deep Hypothermia during Circulatory Arrest in a Piglet Model: A Microdialysis Study

    PubMed Central

    Chen, Guangxian; Tang, Zhixian; Lin, Weibin; Rong, Jian; Wu, Zhongkai

    2016-01-01

    Introduction This study aimed to assess the effects of different temperature settings of hypothermic circulatory arrest (HCA) on intestinal barrier function in a piglet model. Methods Twenty Wuzhishan piglets were randomly assigned to 40 min of HCA at 18°C (DHCA group, n = 5), 40 min of HCA at 24°C (MHCA group, n = 5), normothermic cardiopulmonary bypass (CPB group, n = 5) or sham operation (SO group, n = 5). Serum D-lactate (SDL) and lipopolysaccharide (LPS) levels were determined. Microdialysis parameters (glucose, lactate, pyruvate and glycerol) in the intestinal dialysate were measured. After 180 min of reperfusion, intestinal samples were harvested for real-time polymerase chain reaction and western blotting measurements for E-cadherin and Claudin-1. Results Higher levels of SDL and LPS were detected in the DHCA group than in the MHCA group (P < 0.001). Both MHCA and DHCA groups exhibited lower glucose levels, higher lactate and glycerol levels and a higher lactate to pyruvate (L/P) ratio compared with the CPB group (p<0.05); the DHCA group had higher lactate and glycerol levels and a higher L/P ratio (p<0.05) but similar glucose levels compared to the MHCA group. No significant differences in E-cadherin mRNA or protein levels were noted. Upregulation of claudin-1 mRNA levels was detected in both the DHCA and MHCA animals’ intestines (P < 0.01), but only the DHCA group exhibited a decrease in claudin-1 protein expression (P < 0.01). Conclusion HCA altered the energy metabolism and expression of epithelial junctions in the intestine. Moderate hypothermia (24°C) was less detrimental to the markers of normal functioning of the intestinal barrier than deep hypothermia (18°C). PMID:27685257

  17. Bleeding following deep hypothermia and circulatory arrest in children.

    PubMed

    Mossad, Emad B; Machado, Sandra; Apostolakis, John

    2007-03-01

    Deep hypothermic circulatory arrest (DHCA) is a technique of extracorporeal circulation commonly used in children with complex congenital heart defects undergoing surgical repairs. The use of profound cooling (20 degrees C) and complete cessation of circulation allow adequate exposure and correction of these complex lesions, with enhanced cerebral protection. However, the profound physiologic state of DHCA results in significant derangement of the coagulation system and a high incidence of postoperative bleeding. This review examines the impact of DHCA on bleeding and transfusion requirements in children and the pathophysiology of DHCA-induced platelet dysfunction. It also focuses on possible pharmacologic interventions to decrease bleeding following DHCA in children.

  18. Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia: 2014 update.

    PubMed

    Zafren, Ken; Giesbrecht, Gordon G; Danzl, Daniel F; Brugger, Hermann; Sagalyn, Emily B; Walpoth, Beat; Weiss, Eric A; Auerbach, Paul S; McIntosh, Scott E; Némethy, Mária; McDevitt, Marion; Dow, Jennifer; Schoene, Robert B; Rodway, George W; Hackett, Peter H; Bennett, Brad L; Grissom, Colin K

    2014-12-01

    To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is an updated version of the original Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia published in Wilderness & Environmental Medicine 2014;25(4):425-445.

  19. Survival after cardiopulmonary arrest with extreme hyperkalaemia and hypothermia in a patient with metformin-associated lactic acidosis.

    PubMed

    Tay, Stan; Lee, I-Lynn

    2012-12-20

    Potassium levels are regularly used as a prognostic factor to cease resuscitation in significant hypothermia. In this case report, we highlight how survival is still possible with extreme hyperkalaemia in severe hypothermia. We present a case of a 65-year-old Caucasian man who presented with metformin associated lactic acidosis. On presentation he had potassium of 9.1 mmol/l and a temperature of 31.5 °C. Cardiopulmonary resuscitation was commenced when he went into asystolic arrest. This presentation would commonly make attempts at resuscitation futile with a 100% death rate. However, with appropriate management this patient's condition improved and survival was possible. We provide evidence that survival is possible in profound hyperkalaemia and hypothermia. Effective cardiopulmonary resuscitation with early haemofiltration can be successful.

  20. Therapeutic hypothermia with the use of intracranial pressure monitoring for acute disseminated encephalomyelitis with brainstem lesion: a case report.

    PubMed

    Miyamoto, Kenji; Kozu, Seiki; Arakawa, Akiko; Tsuboi, Tatsuo; Hirao, Jun-Ichi; Ono, Kazuyuki; Arisaka, Osamu

    2014-09-01

    Acute disseminated encephalomyelitis confined to the brainstem is associated with poor prognosis. We describe a case of a 10-year-old boy with acute disseminated encephalomyelitis in the brainstem that developed after influenza A infection. A 10-year-old boy presented with fever and prolonged disturbance of consciousness and was admitted to our hospital. Magnetic resonance imaging (MRI) of the midbrain, with T2-weighted and fluid-attenuated inversion recovery images, suggested acute disseminated encephalomyelitis accompanied by a brainstem lesion. Lumbar puncture showed pleocytosis and increased protein content, including myelin basic protein, interleukin-6, and immunoglobulin G, all suggestive of acute disseminated encephalomyelitis. Treatments such as methylprednisolone pulse therapy, intravenous immunoglobulin, and therapeutic hypothermia were performed. Although the patient presented with anisocoria with increased intracranial pressure monitoring during hypothermia, prompt therapy with d-mannitol and dopamine was effective. Our case results suggest that hypothermia could be included in the choice of therapy for acute disseminated encephalomyelitis with brainstem lesions.

  1. Reversible reduction in dendritic spines in CA1 of rat and ground squirrel subjected to hypothermia-normothermia in vivo: A three-dimensional electron microscope study.

    PubMed

    Popov, V I; Medvedev, N I; Patrushev, I V; Ignat'ev, D A; Morenkov, E D; Stewart, M G

    2007-11-09

    A study was made at electron microscope level of changes in the three-dimensional (3-D) morphology of dendritic spines and postsynaptic densities (PSDs) in CA1 of the hippocampus in ground squirrels, taken either at low temperature during hibernation (brain temperature 2-4 degrees C), or after warming and recovery to the normothermic state (34 degrees C). In addition, the morphology of PSDs and spines was measured in a non-hibernating mammal, rat, subjected to cooling at 2 degrees C at which time core rectal temperature was 15 degrees C, and then after warming to normothermic conditions. Significant differences were found in the proportion of thin and stubby spines, and shaft synapses in CA1 for rats and ground squirrels for normothermia compared with cooling or hibernation. Hypothermia induced a decrease in the proportion of thin spines, and an increase in stubby and shaft spines, but no change in the proportion of mushroom spines. The changes in redistribution of these three categories of spines in ground squirrel are more prominent than in rat. There were no significant differences in synapse density determined for ground squirrels or rats at normal compared with low temperature. Measurement of spine and PSD volume (for mushroom and thin spines) also showed no significant differences between the two functional states in either rats or ground squirrels, nor were there any differences in distances between neighboring synapses. Spinules on dendritic shafts were notable qualitatively during hibernation, but absent in normothermia. These data show that hypothermia results in morphological changes which are essentially similar in both a hibernating and a non-hibernating animal.

  2. Hypothermia Severely Effects Performance of Nitinol-Based Endovascular Grafts In Vitro

    PubMed Central

    Robich, Michael P.; Hagberg, Robert; Schermerhorn, Marc L.; Pomposelli, Frank B.; Nilson, Michael C.; Gendron, Michelle L.; Sellke, Frank W.; Rodriguez, Roberto

    2012-01-01

    Background Nitinol is an alloy that serves as the base for numerous medical devices, including the GORE TAG Thoracic Endoprosthesis (W.L. Gore & Associates, Flagstaff, AZ) thoracic aortic graft device. Given the increasing use of therapeutic hypothermia used during the placement these devices and in post– cardiac arrest situations, we sought to understand the impact of hypothermia on this device. Methods Five 34-mm TAG devices were deployed in a temperature-controlled chamber at 20°C, 25°C, 30°C, 35°, and 37°C (25 total devices). A halographic measurement device was used to measure radial expansive force and normalized to the force at 37°C. Three 34-mm TAG devices were similarly deployed in a temperature-controlled water bath at each of the above temperatures. A laser micrometer was utilized to measure deployed diameter. Results A statistically significant decrease in expansive force at 20°C, 25°C, and 30°C of 65%, 46%, and 6%, respectively, was noted. A statistically significant decrease in radial diameter at 20°C and 25°C of 17% and 11%, respectively, was noted. Although a 9% difference was noted at 30°C, it was not significant. Conclusions The nitinol-based TAG device shows marked decreases in radial expansive force and deployed diameter at temperatures at or below 30°C. Surgeons should be aware of the potential implications of placing nitinol-based endoprostheses in hypothermic conditions. In addition, all health care providers should be aware of the changes that occur in nitinol-based endoprostheses during therapeutic hypothermia. PMID:22385821

  3. Plastic Bags for Prevention of Hypothermia in Preterm and Low Birth Weight Infants

    PubMed Central

    Leadford, Alicia E.; Warren, Jamie B.; Manasyan, Albert; Chomba, Elwyn; Salas, Ariel A.; Schelonka, Robert

    2013-01-01

    BACKGROUND AND OBJECTIVES: Hypothermia contributes to neonatal mortality and morbidity, especially in preterm and low birth weight infants in developing countries. Plastic bags covering the trunk and extremities of very low birth weight infants reduces hypothermia. This technique has not been studied in larger infants or in many resource-limited settings. The objective was to determine if placing preterm and low birth weight infants inside a plastic bag at birth maintains normothermia. METHODS: Infants at 26 to 36 weeks’ gestational age and/or with a birth weight of 1000 to 2500 g born at the University Teaching Hospital in Lusaka, Zambia, were randomized by using a 1:1 allocation and parallel design to standard thermoregulation (blanket or radiant warmer) care or to standard thermoregulation care plus placement inside a plastic bag at birth. The primary outcome measure was axillary temperature in the World Health Organization–defined normal range (36.5–37.5°C) at 1 hour after birth. RESULTS: A total of 104 infants were randomized. At 1 hour after birth, infants randomized to plastic bag (n = 49) were more likely to have a temperature in the normal range as compared with infants in the standard thermoregulation care group (n = 55; 59.2% vs 32.7%; relative risk 1.81; 95% confidence interval 1.16–2.81; P = .007). The temperature at 1 hour after birth in the infants randomized to plastic bag was 36.5 ± 0.5°C compared with 36.1 ± 0.6°C in standard care infants (P < .001). Hyperthermia (>38.0°C) did not occur in any infant. CONCLUSIONS: Placement of preterm/low birth weight infants inside a plastic bag at birth compared with standard thermoregulation care reduced hypothermia without resulting in hyperthermia, and is a low-cost, low-technology tool for resource-limited settings. PMID:23733796

  4. Bolus oral or continuous intestinal amino acids reduce hypothermia during anesthesia in rats.

    PubMed

    Imoto, Akinobu; Yokoyama, Takeshi; Suwa, Kunio; Yamasaki, Fumiyasu; Yatabe, Tomoaki; Yokoyama, Reiko; Yamashita, Koichi; Selldén, Eva

    2010-01-01

    We hypothesized that, with oral or intestinal administration of amino acids (AA), we may reduce hypothermia during general anesthesia as effectively as with intravenous AA. We, therefore, examined the effect of bolus oral and continuous intestinal AA in preventing hypothermia in rats. Male Wistar rats were anesthetized with sevoflurane for induction and with propofol for maintenance. In the first experiment, 30 min before anesthesia, rats received one bolus 42 mL/kg of AA solution (100 g/L) or saline orally. Then for the next 3 h during anesthesia, they received 14 mL/kg/h of AA and/or saline intravenously. They were in 4 groups: I-A/A, both AA; I-A/S, oral AA and intravenous saline; I-S/A, oral saline and intravenous AA; I-S/S, both saline. In the second experiment, rats received 14 mL/kg/h duodenal AA and/or saline for 2 h. They were in 3 groups: II-A/S, duodenal AA and intravenous saline; II-S/A, duodenal saline and intravenous AA; II-S/S, both saline. Core body temperature was measured rectally. After the second experiment, serum electrolytes were examined. In both experiments, rectal temperature decreased in all groups during anesthesia. However, the decrease in rectal temperature was significantly less in groups receiving AA than in groups receiving only saline. In the second experiment, although there was no significant difference in the decrease in body temperature between II-A/S and II-S/A, Na(+) concentration was significantly lower in II-S/A. In conclusion, AA, administered orally or intestinally, tended to keep the body temperature stable during anesthesia without disturbing electrolyte balance. These results suggest that oral or enteral AA may be useful for prevention of hypothermia in patients.

  5. Effects of prehospital hypothermia on transfusion requirements and outcomes: a retrospective observatory trial

    PubMed Central

    Klauke, Nora; Gräff, Ingo; Fleischer, Andreas; Boehm, Olaf; Guttenthaler, Vera; Baumgarten, Georg; Meybohm, Patrick; Wittmann, Maria

    2016-01-01

    Objectives Prehospital hypothermia is defined as a core temperature <36.0°C and has been shown to be an independent risk factor for early death in patients with trauma. In a retrospective study, a possible correlation between the body temperature at the time of admission to the emergency room and subsequent in-hospital transfusion requirements and the in-hospital mortality rate was explored. Setting This is a retrospective single-centre study at a primary care hospital in Germany. Participants 15 895 patients were included in this study. Patients were classified by admission temperature and transfusion rate. Excluded were ambulant patients and patients with missing data. Primary and secondary outcome measures The primary outcome values were length of stay (LOS) in days, in-hospital mortality, the transferred amount of packed red blood cells (PRBCs), and admission to an intensive care unit. Secondary influencing variables were the patient's age and the Glasgow Coma Scale. Results In 22.85% of the patients, hypothermia was documented. Hypothermic patients died earlier in the course of their hospital stay than non-hypothermic patients (p<0.001). The administration of 1–3 PRBC increased the LOS significantly (p<0.001) and transfused patients had an increased risk of death (p<0.001). Prehospital hypothermia could be an independent risk factor for mortality (adjusted OR 8.521; p=0.001) and increases the relative risk for transfusion by factor 2.0 (OR 2.007; p=0.002). Conclusions Low body temperature at hospital admission is associated with a higher risk of transfusion and death. Hence, a greater awareness of prehospital temperature management should be established. PMID:27029772

  6. An uncommon case of severe accidental hypothermia in an urban setting

    PubMed Central

    Meytes, Vadim; Schulberg, Steven P.; Amaturo, Michael; Kilaru, Mohan

    2015-01-01

    Accidental hypothermia is an uncommon presentation in urban settings. Here we present a patient admitted with a core temperature of 26.6°C (80°F) and a serum potassium of 8.5 mmol/l who subsequently went into cardiac arrest. After > 90 min of active cardiopulmonary resuscitation and peak serum potassium of >12 mmol/l, the patient had a spontaneous return of circulation. The patient's hospital course was complicated by compartment syndrome of his forearm; however, he was discharged home without any lasting neurological damage. PMID:26664726

  7. Best strategy for cerebral protection in arch surgery - antegrade selective cerebral perfusion and adequate hypothermia

    PubMed Central

    Mohr, Friedrich W.; Etz, Christian D.

    2013-01-01

    Aortic arch surgery remains a complex surgical operation that necessitates specific neuroprotection strategies. Various approaches, such as hypothermic circulatory arrest (HCA), retrograde cerebral perfusion, and antegrade selective cerebral perfusion (aSCP), have each enjoyed periods of popularity. However, while the overall surgical approach tend to favour HCA with aSCP, technical factors, such as perfusion site, perfusate temperature and flow rate and pH management, have not been conclusively elucidated. The optimal extent of hypothermia during circulatory arrest is also unclear, particularly with recent partiality for warmer temperatures. The following perspective details the preferred surgical practice for cerebral protection in aortic arch surgery, based on existing evidence. PMID:23977602

  8. Amplitude-Integrated Electroencephalography Interpretation During Therapeutic Hypothermia: An Educational Program and Novel Teaching Tool.

    PubMed

    Sacco, Lauren

    2016-01-01

    Therapeutic hypothermia (TH) is now considered a standard in tertiary NICUs. Amplitude-integrated electroencephalography (aEEG) is an important adjunct to this therapy and is gaining acceptance for use on the neonatal population. It can be easily incorporated into practice with appropriate education and training. Current publications are lacking regarding nursing care of neonatal patients undergoing th with the use of aEEG. This article presents a broad educational program as well as novel teaching tool for neonatal nurses caring for this population.

  9. Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia.

    PubMed

    Zafren, Ken; Giesbrecht, Gordon G; Danzl, Daniel F; Brugger, Hermann; Sagalyn, Emily B; Walpoth, Beat; Weiss, Eric A; Auerbach, Paul S; McIntosh, Scott E; Némethy, Mária; McDevitt, Marion; Dow, Jennifer; Schoene, Robert B; Rodway, George W; Hackett, Peter H; Bennett, Brad L; Grissom, Colin K

    2014-12-01

    To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations.

  10. Body temperature changes during simulated bacterial infection in a songbird: fever at night and hypothermia during the day.

    PubMed

    Sköld-Chiriac, Sandra; Nord, Andreas; Tobler, Michael; Nilsson, Jan-Åke; Hasselquist, Dennis

    2015-09-01

    Although fever (a closely regulated increase in body temperature in response to infection) typically is beneficial, it is energetically costly and may induce detrimentally high body temperatures. This can increase the susceptibility to energetic bottlenecks and risks of overheating in some organisms. Accordingly, it could be particularly interesting to study fever in small birds, which have comparatively high metabolic rates and high, variable body temperatures. We therefore investigated two aspects of fever and other sickness behaviours (circadian variation, dose dependence) in a small songbird, the zebra finch. We injected lipopolysaccharide (LPS) at the beginning of either the day or the night, and subsequently monitored body temperature, body mass change and food intake for the duration of the response. We found pronounced circadian variation in the body temperature response to LPS injection, manifested by (dose-dependent) hypothermia during the day but fever at night. This resulted in body temperature during the peak response being relatively similar during the day and night. Day-to-night differences might be explained in the context of circadian variation in body temperature: songbirds have a high daytime body temperature that is augmented by substantial heat production peaks during activity. This might require a trade-off between the benefit of fever and the risk of overheating. In contrast, at night, when body temperature is typically lower and less variable, fever can be used to mitigate infection. We suggest that the change in body temperature during infection in small songbirds is context dependent and regulated to promote survival according to individual demands at the time of infection.

  11. Phenobarbital and temperature profile during hypothermia for hypoxic-ischemic encephalopathy.

    PubMed

    Sant'Anna, Guilherme; Laptook, Abbot R; Shankaran, Seetha; Bara, Rebecca; McDonald, Scott A; Higgins, Rosemary D; Tyson, Jon E; Ehrenkranz, Richard A; Das, Abhik; Goldberg, Ronald N; Walsh, Michele C

    2012-04-01

    Data from the whole-body hypothermia trial was analyzed to examine the effects of phenobarbital administration prior to cooling (+PB) on the esophageal temperature (T (e)) profile, during the induction phase of hypothermia. A total of 98 infants were analyzed. At enrollment, +PB infants had a higher rate of severe hypoxic-ischemic encephalopathy and clinical seizures and lower T (e) and cord pH than infants that have not received phenobarbital (-PB). There was a significant effect of phenobarbital itself and an interaction between phenobarbital and time in the T (e) profile. Mean T (e) in the +PB group was lower than in the -PB group, and the differences decreased over time. In +PB infants, the time to surpass target T (e) of 33.5°C and to reach the minimum T (e) during overshoot were shorter. In conclusion, the administration of phenobarbital before cooling was associated with changes that may reflect a reduced thermogenic response associated with barbiturates.

  12. Automatic Incubator-type Temperature Control System for Brain Hypothermia Treatment

    NASA Astrophysics Data System (ADS)

    Gaohua, Lu; Wakamatsu, Hidetoshi

    An automatic air-cooling incubator is proposed to replace the manual water-cooling blanket to control the brain tissue temperature for brain hypothermia treatment. Its feasibility is theoretically discussed as follows: First, an adult patient with the cooling incubator is modeled as a linear dynamical patient-incubator biothermal system. The patient is represented by an 18-compartment structure and described by its state equations. The air-cooling incubator provides almost same cooling effect as the water-cooling blanket, if a light breeze of speed around 3 m/s is circulated in the incubator. Then, in order to control the brain temperature automatically, an adaptive-optimal control algorithm is adopted, while the patient-blanket therapeutic system is considered as a reference model. Finally, the brain temperature of the patient-incubator biothermal system is controlled to follow up the given reference temperature course, in which an adaptive algorithm is confirmed useful for unknown environmental change and/or metabolic rate change of the patient in the incubating system. Thus, the present work ensures the development of the automatic air-cooling incubator for a better temperature regulation of the brain hypothermia treatment in ICU.

  13. Cerebral blood flow and oxygen metabolism during mild hypothermia in patients with subarachnoid haemorrhage.

    PubMed

    Kawamura, S; Suzuki, A; Hadeishi, H; Yasui, N; Hatazawa, J

    2000-01-01

    Cerebral blood flow and O2 metabolism during hypothermia (33-34 degrees C) was evaluated in 5 patients with aneurysmal subarachnoid haemorrhage by positron emission tomography (PET). Their preoperative clinical condition was WFNS scale IV or V. The patients received surface cooling postoperatively, and were maintained in a hypothermic state during transfer for radiological examination. Positron emission tomography revealed a decrease in cerebral blood flow and O2 metabolic rate. Cerebral blood flow was 34.8+/-15.1 ml/100 ml/min and the O2 metabolic rate was 1.85+/-0.61 ml/100 ml/min in areas of the middle cerebral artery ipsilateral to the ruptured aneurysms, whereas these values were 30.8+/-7.1 and 2.21+/-0.45 ml/100 ml/min, respectively, on the contralateral side. This represents a decrease of 37+/-27% compared to normal cerebral blood flow and 52+/-16% compared to normal O2 metabolic rate (p < 0.02) in the ipsilateral areas, and decreases of 44+/-13% and 43+/-12%, respectively, on the contralateral side. The present results reflected the luxury perfusion state in almost all cases and provide the first PET evidence of decreased cerebral blood flow and metabolic rate of O2 during hypothermia in humans.

  14. Nitric oxide in the nucleus raphe magnus modulates cutaneous blood flow in rats during hypothermia

    PubMed Central

    Arami, Masoumeh Kourosh; zade, Javad Mirnajafi; Komaki, Alireza; Amiri, Mahmood; Mehrpooya, Sara; Jahanshahi, Ali; Jamei, Behnam

    2015-01-01

    Objective(s): Nucleus Raphe Magnus (NRM) that is involved in the regulation of body temperature contains nitric oxide (NO) synthase. Considering the effect of NO on skin blood flow control, in this study, we assessed its thermoregulatory role within the raphe magnus. Materials and Methods: To this end, tail blood flow of male Wistar rats was measured by laser doppler following the induction of hypothermia. Results: Intra-NRM injection of SNP (exogenous NO donor, 0.1- 0.2 μl, 0.2 nM) increased the blood flow. Similarly, unilateral microinjection of glutamate (0.1- 0.2 μl, 2.3 nM) into the nucleus increased the blood flow. This effect of L-glutamate was reduced by prior intra NRM administration of NO synthase inhibitor NG-methyl-L-arginine or NG-nitro-L-arginine methyl ester (L-NAME, 0.1 µl, 100 nM). Conclusion: It is concluded that NO modulates the thermoregulatory response of NRM to hypothermia and may interact with excitatory amino acids in central skin blood flow regulation. PMID:26730333

  15. Automated analysis of background EEG and reactivity during therapeutic hypothermia in comatose patients after cardiac arrest.

    PubMed

    Noirhomme, Quentin; Lehembre, Rémy; Lugo, Zulay Del Rosario; Lesenfants, Damien; Luxen, André; Laureys, Steven; Oddo, Mauro; Rossetti, Andrea O

    2014-01-01

    Visual analysis of electroencephalography (EEG) background and reactivity during therapeutic hypothermia provides important outcome information, but is time-consuming and not always consistent between reviewers. Automated EEG analysis may help quantify the brain damage. Forty-six comatose patients in therapeutic hypothermia, after cardiac arrest, were included in the study. EEG background was quantified with burst-suppression ratio (BSR) and approximate entropy, both used to monitor anesthesia. Reactivity was detected through change in the power spectrum of signal before and after stimulation. Automatic results obtained almost perfect agreement (discontinuity) to substantial agreement (background reactivity) with a visual score from EEG-certified neurologists. Burst-suppression ratio was more suited to distinguish continuous EEG background from burst-suppression than approximate entropy in this specific population. Automatic EEG background and reactivity measures were significantly related to good and poor outcome. We conclude that quantitative EEG measurements can provide promising information regarding current state of the patient and clinical outcome, but further work is needed before routine application in a clinical setting.

  16. A semi-empirical glycosylation model of a camelid monoclonal antibody under hypothermia cell culture conditions.

    PubMed

    Aghamohseni, Hengameh; Spearman, Maureen; Ohadi, Kaveh; Braasch, Katrin; Moo-Young, Murray; Butler, Michael; Budman, Hector M

    2017-03-11

    The impact of cell culture environment on the glycan distribution of a monoclonal antibody (mAb) has been investigated through a combination of experiments and modeling. A newly developed CHO DUXB cell line was cultivated at two levels of initial Glutamine (Gln) concentrations (0, 4 mM) and incubation temperatures of (33 and 37 °C) in batch operation mode. Hypothermia was applied either through the entire culture duration or only during the post-exponential phase. Beyond reducing cell growth and increasing productivity, hypothermia significantly altered the galactosylation index profiles as compared to control conditions. A novel semi-empirical dynamic model was proposed for elucidating the connections between the extracellular cell culture conditions to galactosylation index. The developed model is based on a simplified balance of nucleotides sugars and on the correlation between sugars' levels to the galactosylation index (GI). The model predictions were found to be in a good agreement with the experimental data. The proposed empirical model is expected to be useful for controlling the glycoprofiles by manipulating culture conditions.

  17. Dynamic changes in cortical NADH fluorescence in rat focal ischemia: evaluation of the effects of hypothermia on propagation of peri-infarct depolarization by temporal and spatial analysis.

    PubMed

    Sasaki, Toshihiro; Takeda, Yoshimasa; Taninishi, Hideki; Arai, Minako; Shiraishi, Kensuke; Morita, Kiyoshi

    2009-01-02

    Suppression of peri-infarct depolarizations (PIDs) is one of the major mechanisms of hypothermic protection against transient focal cerebral ischemia. Previous studies have shown the lack of hypothermic protection against permanent focal ischemia. We hypothesized the lack of hypothermic protection was due to the poor efficacy in suppression of PIDs. To examine the hypothesis, we elucidated the effects of hypothermia on the manner of propagation of PIDs with temporal and spatial resolutions using NADH (reduced nicotinamide adenine dinucleotide) fluorescence images by illuminating the parietal-temporal cortex with ultraviolet light. Spontaneously hypertensive rats (n=14) were subjected to permanent focal ischemia by occlusion of the middle cerebral and left common carotid arteries. 2-h hypothermia (30 degrees C) was initiated before ischemia. Although hypothermia delayed the appearance of PIDs, it did not suppress their appearance. Furthermore, 54% of the PIDs enlarged the high-intensity area of NADH fluorescence in the hypothermia group, similar to the normothermia group (53%). The high-intensity area of NADH fluorescence widened by each PID was larger in the hypothermia group than in the normothermia group. These findings suggest that PIDs even in hypothermia are one of the major factors causing growth of infarction, emphasizing the importance of therapy that targets suppression of PIDs even during hypothermia.

  18. CHOLINESTERASE INHIBITION AND HYPOTHERMIA FOLLOWING EXPOSURE TO BINARY MIXTURES OF ANTICHOLINESTERASE AGENTS: LACK OF EVIDENCE FOR CAUSE-AND-EFFECT

    EPA Science Inventory

    Dose-additivity has been the default assumption in risk assessments of pesticides with a common mechanism of action but it has been suspected that there could be non-additive effects. Inhibition of plasma cholinesterase (ChE) activity and hypothermia were used as benchmarks of e...

  19. Therapeutic hypothermia increases the risk of cardiac arrhythmia for perinatal hypoxic ischaemic encephalopathy: A meta-analysis

    PubMed Central

    2017-01-01

    Objective To determine whether therapeutic hypothermia after hypoxic ischaemic encephalopathy (HIE) in neonates increases the risk of cardiac arrhythmia during intervention. Design A meta-analysis was conducted using a fixed-effect model. Risk ratios, risk differences, and 95% confidence intervals, were measured. Data sources Studies identified from the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Google Scholar, previous reviews, and abstracts from onset to August, 2016. Review methods Reports that compared therapeutic hypothermia with normal care for neonates with HIE and that included data on safety or cardiac arrhythmia, which is of interest to patients and clinicians, were selected. Results We found seven trials, encompassing 1322 infants that included information on safety or cardiac arrhythmia during intervention. Therapeutic hypothermia considerably increased the combined rate of cardiac arrhythmia in the seven trials (risk ratio 2.42, 95% confidence interval 1.23 to 4.76. p = 0.01; risk difference 0.02, 95% CI 0.01 to 0.04) during intervention. Conclusions In infants with hypoxic ischaemic encephalopathy, therapeutic hypothermia is associated with a consistent increase in cardiac arrhythmia during intervention. PMID:28273115

  20. Quantitative measurement of cerebral blood flow during hypothermia with a time-resolved near-infrared technique

    NASA Astrophysics Data System (ADS)

    Fazel Bakhsheshi, Mohammad; Diop, Mamadou; St Lawrence, Keith; Lee, Ting-Yim

    2012-02-01

    Hypothermia, in which the brain is cooled to 32-33 °C, has been shown to be neuroprotective for brain injury caused by hypoxia-ischemia, head trauma, or neonatal asphyxia. Neuroprotective effect of Hypothermia is partly due to suppression of brain metabolism and cerebral blood flow (CBF). The ability to measure CBF at the bedside provides a means of detecting, and thereby preventing, secondary ischemia during neuro intensive care before brain injury occurs. The purpose of the present study is to investigate the ability of a time-resolved near-infrared (TR-NIR) bolus-tracking method using indocyanine green as an intravascular flow tracer to measure CBF during cooling in a newborn animal model. For validation, CBF was independently measured by computed tomography (CT) perfusion. The results show a good agreement between CBF obtained with the two methods (R2 ~ 0.84, Δ ~ 5.84 ml. min -1.100 g -1, 32-38.5 °C), demonstrating the ability of the TR-NIR technique to non-invasively measure absolute CBF in-vivo during dynamic hypothermia. The TR-NIR technique reveals that CBF decreases from 54.3 +/- 5.4 ml. min -1.100 g -1, at normothermia (Tbrain of 38.5 °C), to 33.8 +/- 0.9 ml. min -1.100 g -1 at Tbrain of 32 °C during the hypothermia treatment.

  1. Mild hypothermia combined with neural stem cell transplantation for hypoxic-ischemic encephalopathy: neuroprotective effects of combined therapy

    PubMed Central

    Wang, Lin; Jiang, Feng; Li, Qifeng; He, Xiaoguang; Ma, Jie

    2014-01-01

    Neural stem cell transplantation is a useful treatment for ischemic stroke, but apoptosis often occurs in the hypoxic-ischemic environment of the brain after cell transplantation. In this study, we determined if mild hypothermia (27–28°C) can increase the survival rate of neural stem cells (1.0 × 105/μL) transplanted into neonatal mice with hypoxic-ischemic encephalopathy. Long-term effects on neurological functioning of the mice were also examined. After mild hypothermia combined with neural stem cell transplantation, we observed decreased expression levels of inflammatory factor nuclear factor-kappa B and apoptotic factor caspase-3, reduced cerebral infarct volumes, increased survival rate of transplanted cells, and marked improvements in neurological function. Thus, the neuroprotective effects of mild hypothermia combined with neural stem cell transplantation are superior to those of monotherapy. Moreover, our findings suggest that the neuroprotective effects of mild hypothermia combined with neural stem cell transplantation on hypoxic-ischemic encephalopathy are achieved by anti-inflammatory and anti-apoptotic mechanisms. PMID:25422635

  2. Molecular pathology of pulmonary edema in forensic autopsy cases with special regard to fatal hyperthermia and hypothermia.

    PubMed

    Wang, Qi; Ishikawa, Takaki; Michiue, Tomomi; Zhu, Bao-Li; Guan, Da-Wei; Maeda, Hitoshi

    2013-05-10

    Fatalities due to an extreme ambient temperature might present with poor or nonspecific pathologies; thus, the diagnosis of the cause of death in such cases is one of the most difficult tasks in forensic pathology. The present study investigated the molecular pathology of alveolar damage involving pulmonary edema with special regard to hyperthermia (heatstroke) and hypothermia (cold exposure) in forensic autopsy cases (total, n=122; within 48 h postmortem). Intrapulmonary mRNA and immunohistochemical expressions of matrix metalloproteinases (MMPs), intercellular adhesion molecule-1 (ICAM-1), claudin-5 (CLDN-5) and aquaporins (AQPs) were examined. Relative mRNA quantification using Taqman real-time PCR assay demonstrated higher expressions of all markers except for AQP-5 in fatal hyperthermia, and higher expression of MMP-9 in fatal hypothermia. Acute cardiac death, mechanical asphyxiation, fire fatality and intoxication did not present any characteristic findings. In immunostaining, only MMPs showed evident differences among the causes of death: MMP-9 was intensely positive in most cases of hyperthermia and hypothermia, but MMP-2 expression was evident only in hyperthermia. These findings suggest alveolar damage involving pulmonary edema, characteristic of fatal hyperthermia and hypothermia. Systematic analysis of gene expressions using real-time PCR might be a useful procedure in forensic death investigation.

  3. A proposed methodology to control body temperature in patients at risk of hypothermia by means of active rewarming systems.

    PubMed

    Costanzo, Silvia; Cusumano, Alessia; Giaconia, Carlo; Mazzacane, Sante

    2014-01-01

    Hypothermia is a common complication in patients undergoing surgery under general anesthesia. It has been noted that, during the first hour of surgery, the patient's internal temperature (Tcore) decreases by 0.5-1.5°C due to the vasodilatory effect of anesthetic gases, which affect the body's thermoregulatory system by inhibiting vasoconstriction. Thus a continuous check on patient temperature must be carried out. The currently most used methods to avoid hypothermia are based on passive systems (such as blankets reducing body heat loss) and on active ones (thermal blankets, electric or hot-water mattresses, forced hot air, warming lamps, etc.). Within a broader research upon the environmental conditions, pollution, heat stress, and hypothermia risk in operating theatres, the authors set up an experimental investigation by using a warming blanket chosen from several types on sale. Their aim was to identify times and ways the human body reacts to the heat flowing from the blanket and the blanket's effect on the average temperature Tskin and, as a consequence, on Tcore temperature of the patient. The here proposed methodology could allow surgeons to fix in advance the thermal power to supply through a warming blanket for reaching, in a prescribed time, the desired body temperature starting from a given state of hypothermia.

  4. Effects of Cannabidiol and Hypothermia on Short-Term Brain Damage in New-Born Piglets after Acute Hypoxia-Ischemia.

    PubMed

    Lafuente, Hector; Pazos, Maria R; Alvarez, Antonia; Mohammed, Nagat; Santos, Martín; Arizti, Maialen; Alvarez, Francisco J; Martinez-Orgado, Jose A

    2016-01-01

    Hypothermia is a standard treatment for neonatal encephalopathy, but nearly 50% of treated infants have adverse outcomes. Pharmacological therapies can act through complementary mechanisms with hypothermia improving neuroprotection. Cannabidiol could be a good candidate. Our aim was to test whether immediate treatment with cannabidiol and hypothermia act through complementary brain pathways in hypoxic-ischemic newborn piglets. Hypoxic-ischemic animals were randomly divided into four groups receiving 30 min after the insult: (1) normothermia and vehicle administration; (2) normothermia and cannabidiol administration; (3) hypothermia and vehicle administration; and (4) hypothermia and cannabidiol administration. Six hours after treatment, brains were processed to quantify the number of damaged neurons by Nissl staining. Proton nuclear magnetic resonance spectra were obtained and analyzed for lactate, N-acetyl-aspartate and glutamate. Metabolite ratios were calculated to assess neuronal damage (lactate/N-acetyl-aspartate) and excitotoxicity (glutamate/Nacetyl-aspartate). Western blot studies were performed to quantify protein nitrosylation (oxidative stress), content of caspase-3 (apoptosis) and TNFα (inflammation). Individually, the hypothermia and the cannabidiol treatments reduced the glutamate/Nacetyl-aspartate ratio, as well as TNFα and oxidized protein levels in newborn piglets subjected to hypoxic-ischemic insult. Also, both therapies reduced the number of necrotic neurons and prevented an increase in lactate/N-acetyl-aspartate ratio. The combined effect of hypothermia and cannabidiol on excitotoxicity, inflammation and oxidative stress, and on cell damage, was greater than either hypothermia or cannabidiol alone. The present study demonstrated that cannabidiol and hypothermia act complementarily and show additive effects on the main factors leading to hypoxic-ischemic brain damage if applied shortly after the insult.

  5. Effects of Cannabidiol and Hypothermia on Short-Term Brain Damage in New-Born Piglets after Acute Hypoxia-Ischemia

    PubMed Central

    Lafuente, Hector; Pazos, Maria R.; Alvarez, Antonia; Mohammed, Nagat; Santos, Martín; Arizti, Maialen; Alvarez, Francisco J.; Martinez-Orgado, Jose A.

    2016-01-01

    Hypothermia is a standard treatment for neonatal encephalopathy, but nearly 50% of treated infants have adverse outcomes. Pharmacological therapies can act through complementary mechanisms with hypothermia improving neuroprotection. Cannabidiol could be a good candidate. Our aim was to test whether immediate treatment with cannabidiol and hypothermia act through complementary brain pathways in hypoxic-ischemic newborn piglets. Hypoxic-ischemic animals were randomly divided into four groups receiving 30 min after the insult: (1) normothermia and vehicle administration; (2) normothermia and cannabidiol administration; (3) hypothermia and vehicle administration; and (4) hypothermia and cannabidiol administration. Six hours after treatment, brains were processed to quantify the number of damaged neurons by Nissl staining. Proton nuclear magnetic resonance spectra were obtained and analyzed for lactate, N-acetyl-aspartate and glutamate. Metabolite ratios were calculated to assess neuronal damage (lactate/N-acetyl-aspartate) and excitotoxicity (glutamate/Nacetyl-aspartate). Western blot studies were performed to quantify protein nitrosylation (oxidative stress), content of caspase-3 (apoptosis) and TNFα (inflammation). Individually, the hypothermia and the cannabidiol treatments reduced the glutamate/Nacetyl-aspartate ratio, as well as TNFα and oxidized protein levels in newborn piglets subjected to hypoxic-ischemic insult. Also, both therapies reduced the number of necrotic neurons and prevented an increase in lactate/N-acetyl-aspartate ratio. The combined effect of hypothermia and cannabidiol on excitotoxicity, inflammation and oxidative stress, and on cell damage, was greater than either hypothermia or cannabidiol alone. The present study demonstrated that cannabidiol and hypothermia act complementarily and show additive effects on the main factors leading to hypoxic-ischemic brain damage if applied shortly after the insult. PMID:27462203

  6. Intraventricular hemorrhage in term neonates with hypoxic-ischemic encephalopathy: a comparison study between neonates treated with and without hypothermia

    PubMed Central

    Gorelik, Natalia; Daneman, Alan; Epelman, Monica

    2016-01-01

    Background To retrospectively determine the prevalence of intraventricular hemorrhage (IVH) in term neonates with hypoxic-ischemic encephalopathy (HIE) using head ultrasound (HUS) and MRI, and to compare the incidence of IVH in term babies with HIE treated by therapeutic hypothermia versus those managed conventionally. Methods A total of 61 term neonates from two institutions were diagnosed with HIE shortly after birth. Thirty infants from one institution were treated with whole body hypothermia. These infants had to satisfy the entry criteria for the neonatal hypothermia protocol of the institution. Thirty-one neonates underwent conventional treatment at the second institution. At that time, hypothermia was not yet a standard of care at that institution. All the neonates underwent HUS in their first 23 days of life. The 54 survivors also underwent MRI. The imaging studies were all reviewed for IVH. Results Amongst the 30 babies, who received whole body hypothermia, there were 18 males and 12 females, the mean birth weight was 3.5 kg (2.5 to 5.2 kg), and the HUS study was performed within 14.8 to 41 hours of life. The group of 31 infants treated conventionally was comprised of 12 boys and 19 girls, the infants had an average birth weight of 3.3 kg (2.3 to 4.2 kg), and they underwent HUS 1 to 23 days after birth, with only five children being older than 1 week at the time of the imaging studies. Four of the 61 infants (7%) were diagnosed with IVH on HUS. Three were confirmed with MRI. The fourth case showed a bilateral enlarged choroid plexus on HUS, but IVH could not be confirmed with MRI, as the infant did not survive. In the group of neonates treated with hypothermia, there were three cases (10%) of IVH, whereas in the group managed conventionally, IVH occurred in one infant (3%). Conclusions Our study shows that IVH remains uncommon in term infants with HIE. IVH was more prevalent in the group treated with hypothermia. PMID:27942469

  7. Passive hypothermia (≥35 - <36°C) during transport of newborns with hypoxic-ischaemic encephalopathy

    PubMed Central

    Sellam, Aurélie; Lode, Noëlla; Ayachi, Azzedine; Jourdain, Gilles; Dauger, Stéphane; Jones, Peter

    2017-01-01

    Background Hypothermia initiated in the first six hours of life in term infants with hypoxic ischemic encephalopathy reduces the risk of death and severe neurological sequelae. Our study's principal objective was to evaluate transport predictors potentially influencing arrival in NICU (Neonatal Intensive Care Unit) at a temperature ≥35-<36°C. Methodology/Principal findings A multi-centric, prospective cohort study was conducted during 18 months by the three Neonatal Transport Teams and 13 NICUs. Newborns were selected for inclusion according to biological and clinical criteria before transport using passive hypothermia using a target temperature of ≥35-<36°C. Data on 120 of 126 inclusions were available for analysis. Thirty-three percent of the children arrived in NICU with the target temperature of ≥35-<36°C. The mean temperature for the whole group of infants on arrival in NICU was 35.4°C (34.3–36.5). The median age of all infants on arrival in NICU was 3h03min [2h25min-3h56min]. Three infants arrived in NICU with a temperature of <33°C and eleven with a temperature ≥37°C. Adrenaline during resuscitation was associated with a lower mean temperature on arrival in NICU. Conclusions/Significance Our strategy using ≥35-<36°C passive hypothermia combined with short transport times had little effect on temperature after the arrival of Neonatal Transport Team although did reduce numbers of infants arriving in NICU in deep hypothermia. For those infants where hypothermia was discontinued in NICU our strategy facilitated re-warming. Re-adjustment to a lower target temperature to ≥34.5-<35.5°C may reduce the proportion of infants with high/normothermic temperatures. PMID:28278217

  8. Cardiac condition during cooling and rewarming periods of therapeutic hypothermia after cardiopulmonary resuscitation

    PubMed Central

    2014-01-01

    Background Hypothermia has been used in cardiac surgery for many years for neuroprotection. Mild hypothermia (MH) [body temperature (BT) kept at 32–35°C] has been shown to reduce both mortality and poor neurological outcome in patients after cardiopulmonary resuscitation (CPR). This study investigated whether patients who were expected to benefit neurologically from therapeutic hypothermia (TH) also had improved cardiac function. Methods The study included 30 patients who developed in-hospital cardiac arrest between September 17, 2012, and September 20, 2013, and had return of spontaneous circulation (ROSC) following successful CPR. Patient BTs were cooled to 33°C using intravascular heat change. Basal BT, systolic artery pressure (SAP), diastolic artery pressure (DAP), mean arterial pressure (MAP), heart rate, central venous pressure, cardiac output (CO), cardiac index (CI), global end-diastolic volume index (GEDI), extravascular lung water index (ELWI), and systemic vascular resistance index (SVRI) were measured at 36°C, 35°C, 34°C and 33°C during cooling. BT was held at 33°C for 24 hours prior to rewarming. Rewarming was conducted 0.25°C/h. During rewarming, measurements were repeated at 33°C, 34°C, 35°C and 36°C. A final measurement was performed once patients spontaneously returned to basal BT. We compared cooling and rewarming cardiac measurements at the same BTs. Results SAP values during rewarming (34°C, 35°C and 36°C) were lower than during cooling (P < 0.05). DAP values during rewarming (basal temperature, 34°C, 35°C and 36°C) were lower than during cooling. MAP values during rewarming (34°C, 35°C and 36°C) were lower than during cooling (P < 0.05). CO and CI values were higher during rewarming than during cooling. GEDI and ELWI did not differ during cooling and rewarming. SVRI values during rewarming (34°C, 35°C, 36°C and basal temperature) were lower than during cooling (P < 0.05). Conclusions To our knowledge

  9. Safety and efficacy of vinyl bags in prevention of hypothermia of preterm neonates at birth.

    PubMed

    Gathwala, Geeta; Singh, Gurmeet; Agrawal, Nitika

    2010-01-01

    The present study was planned to evaluate the safety and efficacy of vinyl bags in prevention of hypothermia during resuscitation at birth in very low birth weight neonates. Sixty neonates of gestational age ≤32 weeks and birth weight ≤ 1500gm were randomised to either study group, or control group. Study group neonates were put in vinyl bags up to neck and the head was covered with a cap after drying immediately following delivery and resuscitated under radiant warmer. Control group neonates were resuscitated by conventional drying under radiant warmer. Mean axillary and rectal temperature recorded immediately after admission to NICU were significantly higher in the study group compared to control group. Temperature recorded after 1 hour of admission to NICU were however comparable between the two groups. As temperature maintenance in these VLBW neonates is of tremendous importance, it would make sense to recommend the use of vinyl bags during their resuscitation.

  10. Repair of traumatic aortic arch to innominate vein fistula under deep hypothermia and circulatory arrest.

    PubMed Central

    Astolfi, D; di Carlo, D; di Eusanio, G; Marcelletti, C

    1976-01-01

    Penetrating injuries of the thoracic aorta are usually rapidly lethal. Few patients survive for long enough to undergo surgical treatment. When penetrating injuries of the thoracic aorta are complicated by arteriovenous fistula a correct preoperative diagnosis is important for adequate planning of the surgical repair, and so selective angiography is essential. The best approach is through a median sternotomy with the use of total cardiopulmonary bypass with or without deep hypothermia and circulatory arrest. Fistulae between aorta and innominate vein invariably lead to congestive cardiac failure. A review of the literature suggests that signs of cardiac failure rarely appear early. Congestive failure developed within 30 days of the initial trauma in only two of the 12 reported cases. In our case, the early onset of cardac failure refractory to therapy and the appearance of an expanding pulsatile mass at the base of the neck, threatening rupture, necessitated emergency surgical treatment. Images PMID:797045

  11. Restraint hypothermia in cold-exposed rats at 3 G and 1 G

    NASA Technical Reports Server (NTRS)

    Monson, C. B.; Horowitz, J. M.; Horwitz, B. A.

    1982-01-01

    The relationship between heat loss, heat production, and hypothermia was investigated in experiments with rats which determined if hypergravity affects heat production by altering oxygen consumption and if restraint modifies the ability of the rats to activate thermogenic mechanisms after cold exposure in a hypergravic field. Restrained and unrestrained rats were exposed for 1 hr periods to 1 G and 3 G at ambient temperatures of 24 C or 10 C, and the rate of oxygen consumption, the core temperatures, and the tail temperatures were measured. Results show that thermoregulatory mechanisms are impaired when rats are exposed to 3 G fields, and at 24 C as well as at 10 C this impairment leads to an inappropriate increase in heat loss.

  12. [Comparative morphometric analysis of rat embryonic and fetal pulmonary structures after general hypothermia].

    PubMed

    Tseluĭko, S S; Gordienko, E N

    2005-01-01

    The applied model of morphological assessment of the lung at strictly dated stages of embryonic (gestational day 14) and fetal (gestational day 20) development permitted to specify major planimetric parameters of organ parenchyma, the magnitudes of form-factors of the objects studied. On the basis of morphometric criteria, two main phenotypical variants of rat lung development were established. The factor of hypothermia, by modifying the limits of normal development, "typifies" its variants already in embryonic and perinatal periods with the participation of preacinar regions. This phenomenon is a manifestation of an individual intrauterine preadaptation by the formation of individual variants of "effect of readiness" to the challenge by a similar factor after birth with the object of probable minimal expenditures for the organism.

  13. Effect of ultra-fast mild hypothermia using total liquid ventilation on hemodynamics and respiratory mechanics.

    PubMed

    Sage, Michaël; Nadeau, Mathieu; Kohlhauer, Matthias; Praud, Jean-Paul; Tissier, Renaud; Robert, Raymond; Walti, Hervé; Micheau, Philippe

    2016-08-01

    Ultra-fast cooling for mild therapeutic hypothermia (MTH) has several potential applications, including prevention of post-cardiac arrest syndrome. Ultra-fast MTH by total liquid ventilation (TLV) entails the sudden filling of the lungs with a cold perfluorocarbon liquid and its subsequent use to perform TLV. The present physiological study was aimed at assessing whether pulmonary and systemic hemodynamics as well as lung mechanics are significantly altered during this procedure. Pulmonary and systemic arterial pressures, cardiac output as well as airway resistance and respiratory system compliance were measured during ultra-fast MTH by TLV followed by rewarming and normothermia in six healthy juvenile lambs. Results show that none of the studied variables were altered upon varying the perfluorocarbon temperature from 12 to 41 °C. It is concluded that ultra-fast MTH by TLV does not have any deleterious effect on hemodynamics or lung mechanics in healthy juvenile lambs.

  14. [Current cooling methods for induction of mild hypothermia in cardiac arrest survivors].

    PubMed

    Skulec, R; Truhlár, A; Ostádal, P; Telekes, P; Knor, J; Tichácek, M; Cerný, V; Seblová, J

    2009-11-01

    Induction of mild therapeutic hypothermia early after return of spontaneous circulation improves prognosis of cardiac arrest survivors. Rapid cooling of the patients and correct maintainance of the target therapeutic temperature followed by controlled slow rewarming can be achieved by several noninvasive and invasive methods of various efficacy. Elementary and the most frequently used methods are surface cooling via ice-packs and rapid intravenous administration of cold crystaloids. Mattress cooling systems and facilities for endovascular cathether-cooling are more sophisticated, manageable and ensure more precise titration of therapeutic temperature. Cooling caps and helmets leading to selective head cooling can be used as the complementary techniques. Several other methods are too instrumentation-intensive, too invasive or investigated in animal experiments only. Anyway, near future may bring a rapid development of new effective and safe cooling systems.

  15. Microparticulate ICE slurry for renal hypothermia: laparoscopic partial nephrectomy in a porcine model.

    SciTech Connect

    Shikanov, S; Wille, M; Large, M; Razmaria, A; Lifshitz, D; Chang, A; Wu, Y; Kasza, K; Shalhav, A

    2010-10-01

    Previously, we described the feasibility of renal hypothermia using microparticulate ice slurry during laparoscopy. In the present study, we compared surface cooling with the ice slurry versus near-frozen saline or warm ischemia (WI) during laparoscopic partial nephrectomy (LPN) in a porcine model. We used a single-kidney porcine model. Animals in 5 equal groups (n = 6 each) underwent right laparoscopic complete nephrectomy. In Phase I, left LPN was performed under 90 minutes of ischemia and 90-minute renal cooling with either slurry (Slurry group 1) or saline (Saline group 1). No cooling was applied in the WI group. In Phase II, to simulate more extreme condition, ischemia time was extended to 120 minutes and cooling shortened to 10 minutes (Slurry group 2 and Saline group 2). The study endpoints were renal and core temperature during the surgery and serum creatinine at baseline and days 1, 3, 7, and 14 after the procedure. The ice slurry was easily produced and delivered. Nadir renal temperature (mean {+-} SD) was 8 {+-} 4 C in Slurry group 1 vs. 22.5 {+-} 3 C in Saline group 1 (P < .0001). Renal rewarming to 30 C occurred after 61 {+-} 7 minutes in Slurry group 2 vs. 24 {+-} 6 minutes in Saline group 2 (P < .0001). Core temperature decreased on average to 35 C in the Saline groups compared with 37 C in the Slurry groups (P < .0001). Serum creatinine did not differ between the Saline and Slurry groups in Phases I and II at any time point. Ice slurry provides superior renal cooling compared with near-frozen saline during LPN without associated core hypothermia.

  16. Cost-effective therapeutic hypothermia treatment device for hypoxic ischemic encephalopathy

    PubMed Central

    Kim, John J; Buchbinder, Nathan; Ammanuel, Simon; Kim, Robert; Moore, Erika; O’Donnell, Neil; Lee, Jennifer K; Kulikowicz, Ewa; Acharya, Soumyadipta; Allen, Robert H; Lee, Ryan W; Johnston, Michael V

    2013-01-01

    Despite recent advances in neonatal care and monitoring, asphyxia globally accounts for 23% of the 4 million annual deaths of newborns, and leads to hypoxic-ischemic encephalopathy (HIE). Occurring in five of 1000 live-born infants globally and even more in developing countries, HIE is a serious problem that causes death in 25%–50% of affected neonates and neurological disability to at least 25% of survivors. In order to prevent the damage caused by HIE, our invention provides an effective whole-body cooling of the neonates by utilizing evaporation and an endothermic reaction. Our device is composed of basic electronics, clay pots, sand, and urea-based instant cold pack powder. A larger clay pot, lined with nearly 5 cm of sand, contains a smaller pot, where the neonate will be placed for therapeutic treatment. When the sand is mixed with instant cold pack urea powder and wetted with water, the device can extract heat from inside to outside and maintain the inner pot at 17°C for more than 24 hours with monitoring by LED lights and thermistors. Using a piglet model, we confirmed that our device fits the specific parameters of therapeutic hypothermia, lowering the body temperature to 33.5°C with a 1°C margin of error. After the therapeutic hypothermia treatment, warming is regulated by adjusting the amount of water added and the location of baby inside the device. Our invention uniquely limits the amount of electricity required to power and operate the device compared with current expensive and high-tech devices available in the United States. Our device costs a maximum of 40 dollars and is simple enough to be used in neonatal intensive care units in developing countries. PMID:23319871

  17. Hypothermia and amiloride preserve energetics in a neonatal brain slice model.

    PubMed

    Robertson, Nicola J; Bhakoo, Kishore; Puri, Basant K; Edwards, A David; Cox, I Jane

    2005-08-01

    A period of secondary energy failure consisting of a decline in phosphocreatine/inorganic phosphate (PCr/Pi), a rise in brain lactate, and alkaline intracellular pH (pH(i)) has been described in infants with neonatal encephalopathy. Strategies that ameliorate this energy failure may be neuroprotective. We hypothesized that a neonatal rat brain slice model undergoes a progressive decline in energetics, which can be ameliorated with hypothermia or amiloride. Interleaved phosphorus ((31)P) and proton ((1)H) magnetic resonance (MR) spectra were obtained from 350 microm neonatal rat brain slices over 8 h in a bicarbonate buffer at 37 degrees C and at 32 degrees C in 7- and 14-d models. (31)P MR spectra were obtained with amiloride in a bicarbonate-free buffer at 37 degrees C in the 14-d model. Findings were similar in 7- and 14-d models. In the 14-d model, there was a Pi doublet structure corresponding to alkaline pH(i) values of 7.50 +/- 0.02 and 7.21 +/- 0.04. Compared with the stabilized baseline of 100, at 5 h PCr/Pi was 65 +/- 6.3 and lactate/NAA was 187 +/- 3 at 37 degrees C, but PCr/Pi and lactate/NAA were not significantly different from baseline at 32 degrees C. Nucleotide triphosphate (NTP)/phosphomonoester (PME) was 0.93 +/- 0.23 at 37 degrees C and 1.81 +/- 0.21 at 32 degrees C at 5 h. With amiloride exposure in the 14-d model, baseline pH(i) values were 7.25 +/- 0.09 and 6.98 +/- 0.02 and NTP/PME was 1.81 +/- 0.05; these parameters were not significantly different at 5 h. Our interpretation of these findings is that the brain slice model underwent secondary energy failure, which was delayed with hypothermia or amiloride.

  18. Short-term moderate hypothermia stimulates alkaline phosphatase activity and osteocalcin expression in osteoblasts by upregulating Runx2 and osterix in vitro.

    PubMed

    Aisha, M D; Nor-Ashikin, M N K; Sharaniza, A B; Nawawi, H M; Kapitonova, M Y; Froemming, G R A

    2014-08-01

    Exposure of Normal Human Osteoblast cells (NHOst) to a period of hypothermia may interrupt their cellular functions, lead to changes in bone matrix and disrupt the balance between bone formation and resorption, resulting in bone loss or delayed fracture healing. To investigate this possibility, we exposed NHOst cells to moderate (35 °C) and severe (27 °C) hypothermia for 1, 12, 24 and 72 h. The effects of hypothermia with respect to cell cytoskeleton organization, metabolic activity and the expression of cold shock chaperone proteins, osteoblast transcription factors and functional markers, were examined. Our findings showed that prolonged moderate hypothermia retained the polymerization of the cytoskeletal components. NHOst cell metabolism was affected differently according to hypothermia severity. The osteoblast transcription factors Runx2 and osterix were necessary for the transcription and translation of bone matrix proteins, where alkaline phosphatase (Alp) activity and osteocalcin (OCN) bone protein were over expressed under hypothermic conditions. Consequently, bone mineralization was stimulated after exposure to moderate hypothermia for 1 week, indicating bone function was not impaired. The cold shock chaperone protein Rbm3 was significantly upregulated (p<0.001) during the cellular stress adaption under hypothermic conditions. We suggest that Rbm3 has a dual function: one as a chaperone protein that stabilizes mRNA transcripts and a second one in enhancing the transcription of Alp and Ocn genes. Our studies demonstrated that hypothermia permitted the in vitro maturation of NHOst cells probably through an osterix-dependent pathway. For that reason, we suggest that moderate hypothermia can be clinically applied to counteract heat production at the fracture site that delays fracture healing.

  19. [Subcutaneous fat necrosis and persistent hypercalcaemia in a newborn treated with therapeutic neonatal hypothermia. A case report].

    PubMed

    Martínez de Zabarte Fernández, José M; Laliena Aznar, Sara; Corella Aznar, Elena; Cuadrado Piqueras, Laura; Oliván del Cacho, María J; Pinillos Pisón, Raquel

    2016-02-01

    Therapeutic hypothermia is the current standard treatment in newborns with moderate to severe hypoxic-ischemic encephalopathy, changing the outcome of these children. It is considered a safe technique with almost no side effects. A possible adverse side event is subcutaneous fat necrosis, which is an acute self-limiting panniculitis that develops during the first weeks of life. We report a case of a newborn at term suffering hypoxic-ischemic encephalopathy with a generalized multiform erythematous rash and firm and indurated plaques over the back, buttocks and extremities on his 12th day of life after being treated with therapeutic hypothermia. Histopathological study after skin punchbiopsy confirmed the suspicion of subcutaneous fat necrosis. The infant developed asymptomatic moderate hypercalcaemia within the first month of life, which was treated with intravenous fluids and diuretics. Serum calcium levels decreased and normalized in 3 months, with progressive disappearance of skin lesions.

  20. 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.

  1. Effects of hypothermia combined with neural stem cell transplantation on recovery of neurological function in rats with spinal cord injury

    PubMed Central

    WANG, DONG; ZHANG, JIANJUN

    2015-01-01

    The microenvironment of the injured spinal cord is hypothesized to be involved in driving the differentiation and survival of engrafted neural stem cells (NSCs). Hypothermia is known to improve the microenvironment of the injured spinal cord in a number of ways. To investigate the effect of NSC transplantation in combination with hypothermia on the recovery of rat spinal cord injury, 60 Sprague-Dawley female rats were used to establish a spinal cord hemisection model. They were divided randomly into three groups: A, spinal cord injury group; B, NSC transplantation group; and C, NSC transplantation + hypothermia group. At 1, 2, 4, 6 and 8 weeks post-injury, the motor function of all animals was evaluated using the Basso, Beattie and Besnaham locomotor scoring system and the inclined plane test. At 4 weeks post-transplantation, histological analysis and immunocytochemistry were performed. At 8 weeks post-transplantation, horseradish peroxidase nerve tracing and transmission electron microscopy were conducted to observe axonal regeneration. The outcome of hind limb motor function recovery in group C significantly surpassed that in group B at 4 weeks post-injury (P<0.05). Recovery was also observed in group A, but to a lesser degree. For the pathological sections no neural axonal were observed in group A. A few axon-like structures were observed in group B and more in group C. Horseradish peroxidase-labeled neurofibers and bromodeoxyuridine-positive cells were observed in the spinal cords of group C. Fewer of these cells were found in group B and fewer still in group A. The differences among the three groups were significant (P<0.05). Using transmission electron microscopy, newly formed nerve fibers and myelinated nerve fibers were observed in the central transverse plane in groups B and C, although these nerve fibers were not evident in group A. In conclusion, NSC transplantation promoted the recovery of hind limb function in rats, and combination treatment with

  2. Basal ganglia perfusion using dynamic color Doppler sonography in infants with hypoxic ischemic encephalopathy receiving therapeutic hypothermia: a pilot study

    PubMed Central

    Cassia, Guilherme; Morneault, Linda; Saint-Martin, Christine; Sant’Anna, Guilherme

    2016-01-01

    Background The objective of this study was to evaluate the cerebral perfusion of the basal ganglia in infants with hypoxic-ischemic encephalopathy (HIE) receiving hypothermia using dynamic color Doppler sonography (CDS) and investigate for any correlation between these measurements and survival. Methods Head ultrasound (HUS) was performed with a 9S4 MHz sector transducer in HIE infants submitted to hypothermia as part of their routine care. Measurements of cerebral perfusion intensity (CPI) with an 11LW4 MHz linear array transducer were performed to obtain static images and DICOM color Doppler videos of the blood flow in the basal ganglia area. Clinical and radiological data were evaluated retrospectively. The video images were analyzed by two radiologists using dedicated software, which allows automatic quantification of color Doppler data from a region of interest (ROI) by dynamically assessing color pixels and flow velocity during the heart cycle. CPI is expressed in cm/sec and is calculated by multiplying the mean velocity of all pixels divided by the area of the ROI. Three videos of 3 seconds each were obtained of the ROI, in the coronal plane, and used to calculate the CPI. Data are presented as mean ± SEM or median (quartiles). Results A total of 28 infants were included in this study: 16 male, 12 female. HUS was performed within the first 48 hours of therapeutic hypothermia treatment. CPI values were significantly higher in the seven non-survivors when compared to survivors (0.226±0.221 vs. 0.111±0.082 cm/sec; P=0.02). Conclusions Increased perfusion intensity of the basal ganglia area within the first 48 of therapeutic hypothermia treatment was associated with poor outcome in neonates with HIE. PMID:27942470

  3. Evidence for the Therapeutic Efficacy of Either Mild Hypothermia or Oxygen Radical Scavengers after Repetitive Mild Traumatic Brain Injury

    PubMed Central

    Miyauchi, Takashi; Wei, Enoch P.

    2014-01-01

    Abstract Repetitive brain injury, particularly that occurring with sporting-related injuries, has recently garnered increased attention in both the clinical and public settings. In the laboratory, we have demonstrated the adverse axonal and vascular consequences of repetitive brain injury and have demonstrated that moderate hypothermia and/or FK506 exerted protective effects after repetitive mild traumatic brain injury (mTBI) when administered within a specific time frame, suggesting a range of therapeutic modalities to prevent a dramatic exacerbation. In this communication, we revisit the utility of targeted therapeutic intervention to seek the minimal level of hypothermia needed to achieve protection while probing the role of oxygen radicals and their therapeutic targeting. Male Sprague-Dawley rats were subjected to repetitive mTBI by impact acceleration injury. Mild hypothermia (35°C, group 2), superoxide dismutase (group 3), and Tempol (group 4) were employed as therapeutic interventions administered 1 h after the repetitive mTBI. To assess vascular function, cerebral vascular reactivity to acetylcholine was evaluated 3 and 4 h after the repetitive mTBI, whereas to detect the burden of axonal damage, amyloid precursor protein (APP) density in the medullospinal junction was measured. Whereas complete impairment of vascular reactivity was observed in group 1 (without intervention), significant preservation of vascular reactivity was found in the other groups. Similarly, whereas remarkable increase in the APP-positive axon was observed in group 1, there were no significant increases in the other groups. Collectively, these findings indicate that even mild hypothermia or the blunting free radical damage, even when performed in a delayed period, is protective in repetitive mTBI. PMID:24341607

  4. Rewarming Rate of the Myocardium During the Aortic Cross-Clamp Time: Variations with Different Levels of Body Hypothermia

    PubMed Central

    Juffé, Alberto; Burgos, Raul; Montero, Carlos Garcia; Tellez, Gaberiel; Prades, Gonzalo; Lloves, Eduardo; Figuera, Diego

    1985-01-01

    Twenty patients underwent elective cardiac valve replacement at 20° C of body hypothermia. Temperatures of the ventricles of both walls were monitored on 12 different sites. Distribution of myocardial temperature ranged between 24.3 and 29.3° C for patients of Group I before cardioplegia delivery and 13.2° C in the septum after cardioplegic infusion. Average temperatures for the anterior and posterior wall were 13.6 C and 15° C in the left ventricle and 14.7 and 15° C in the right ventricle. Myocardial temperatures ranged from 26 to 28.7° C for patients of Group II. After cardioplegic arrest, septal temperatures averaged 14.9° C. The recorded sites of the anterior and posterior left ventricle were 14.1 and 13.1° C. The effects of rewarming on the different myocardial areas occurred according to a logarithmic equation, which is faster in the first 10 minutes. The data suggest that the myocardium can be adequately protected with 25° C hypothermia when the cross-clamp period is shorter than 60 minutes. When longer ischemic periods are expected, myocardial protection is best accomplished with 20° C hypothermia. PMID:15227003

  5. An objective approach using three indexes for determining fatal hypothermia due to cold exposure; statistical analysis of oxyhemoglobin saturation data.

    PubMed

    Yajima, Daisuke; Asari, Masaru; Okuda, Katsuhiro; Maseda, Chikatoshi; Yamada, Hiromi; Ichimaru, Chisato; Matsubara, Kazuo; Shiono, Hiroshi; Iwase, Hirotaro; Makino, Yosuke; Shimizu, Keiko

    2015-11-01

    Analysis of oxyhemoglobin (O2-Hb) saturation levels in the left and right heart blood is useful in the assessment of exposure to cold surroundings before death. We quantified conventional subjective visual evaluation of O2-Hb saturation levels and developed useful diagnostic criteria for fatal hypothermia: O2-Hb saturation in the left heart blood (L-O2Hb) was ⩾36%, the O2-Hb saturation gap between the left and right heart blood (L-R gap) was ⩾13%, and the O2-Hb saturation ratio of the left to right heart blood (L/R ratio) was ⩾1.8. When we used L-O2Hb of ⩾36% as a basic criterion and applied a further criterion of an L-R gap of ⩾13% or an L/R ratio of ⩾1.8, these criteria registered a sensitivity level of ⩾86% and specificity level of ⩾93% for the diagnosis of fatal hypothermia. This method can be useful for determining fatal hypothermia in connection with conventional autopsy findings, as well as histological and biochemical markers.

  6. Coupling of cerebral blood flow and oxygen consumption during hypothermia in newborn piglets as measured by time-resolved near-infrared spectroscopy: a pilot study

    PubMed Central

    Bakhsheshi, Mohammad Fazel; Diop, Mamadou; Morrison, Laura B.; St. Lawrence, Keith; Lee, Ting-Yim

    2015-01-01

    Abstract. Hypothermia (HT) is a potent neuroprotective therapy that is now widely used in following neurological emergencies, such as neonatal asphyxia. An important mechanism of HT-induced neuroprotection is attributed to the associated reduction in the cerebral metabolic rate of oxygen (CMRO2). Since cerebral circulation and metabolism are tightly regulated, reduction in CMRO2 typically results in decreased cerebral blood flow (CBF); it is only under oxidative stress, e.g., hypoxia-ischemia, that oxygen extraction fraction (OEF) deviates from its basal value, which can lead to cerebral dysfunction. As such, it is critical to measure these key physiological parameters during therapeutic HT. This report investigates a noninvasive method of measuring the coupling of CMRO2 and CBF under HT and different anesthetic combinations of propofol/nitrous-oxide (N2O) that may be used in clinical practice. Both CBF and CMRO2 decreased with decreasing temperature, but the OEF remained unchanged, which indicates a tight coupling of flow and metabolism under different anesthetics and over the mild HT temperature range (38°C to 33°C). PMID:26835481

  7. Successful use of therapeutic hypothermia after cardiac arrest due to amitriptyline and venlafaxine intoxication.

    PubMed

    Kontio, Terhi; Salo, Ari; Kantola, Teemu; Toivonen, Lauri; Skrifvars, Markus B

    2015-06-01

    The prognosis of out-of-hospital cardiac arrest (OHCA) due to intoxication is dismal. Tricyclic antidepressants (TCAs) are widely used in the treatment of depression, but possess significant cardiotoxicity, and are one of the most common medications used in suicide attempts worldwide. TCA poisoning can cause hypotension, seizures, and cardiac conduction disturbances, which can lead to life-threatening arrhythmia. Current guidelines recommend mild therapeutic hypothermia (TH) for unconscious survivors of OHCA, but hypothermia treatment itself can cause disturbances in cardiac conduction, which could aggravate the effect of TCAs on cardiac conduction. We report the successful use of TH in a 19-year-old woman who was resuscitated from ventricular tachycardia after intentional ingestion of amitriptyline and venlafaxine, a serotonin-norepinephrine reuptake inhibitor. The cardiac arrest was witnessed, but no bystander cardiopulmonary resuscitation (CPR) was performed. The initial rhythm was ventricular tachycardia with no detectable pulse. Three defibrillations, magnesium sulfate, and sodium bicarbonate were given and her trachea was intubated, after which return of spontaneous circulation (ROSC) was achieved in 26 minutes. After ROSC, she had seizures and was sedated with propofol. Out-of-hospital TH was initiated with 1500 mL of cold Ringer's acetate. An infusion of norepinephrine was initiated for low blood pressure. On arrival at the university hospital, she was unconscious and had dilated pupils. She was tachycardic with a body temperature of 33.5°C. She was transferred to the intensive care unit and TH was maintained with invasive cooling. During the TH treatment, she did not experience any serious cardiac arrhythmia, transthoracic echocardiogram was normal, and the electrocardiogram (ECG) returned to normal. The patient was extubated 45 hours after the cardiac arrest. After the extubation, she was alert and cooperative, but slightly delusional. She was

  8. Implication of prostaglandins and histamine H1 and H2 receptors in radiation-induced temperature responses of rats

    SciTech Connect

    Kandasamy, S.B.; Hunt, W.A.; Mickley, G.A.

    1988-04-01

    Exposure of rats to 1-15 Gy gamma radiation (/sup 60/Co) induced hyperthermia, whereas 20-200 Gy induced hypothermia. Exposure either to the head or to the whole body to 10 Gy induced hyperthermia, while body-only exposure produced hypothermia. This observation indicates that radiation-induced fever is a result of a direct effect on the brain. The hyperthermia due to 10 Gy was significantly attenuated by the pre- or post-treatment with a cyclooxygenase inhibitor, indomethacin. Hyperthermia was also altered by the central administration of a mu-receptor antagonist naloxone but only at low doses of radiation. These findings suggest that radiation-induced hyperthermia may be mediated through the synthesis and release of prostaglandins in the brain and to a lesser extent to the release of endogenous opioid peptides. The release of histamine acting on H1 and H2 receptors may be involved in radiation-induced hypothermia, since both the H1 receptor antagonist, mepyramine, and H2 receptor antagonist, cimetidine, antagonized the hypothermia. The results of these studies suggest that the release of neurohumoral substances induced by exposure to ionizing radiation is dose dependent and has different consequences on physiological processes such as the regulation of body temperature. Furthermore, the antagonism of radiation-induced hyperthermia by indomethacin may have potential therapeutic implications in the treatment of fever resulting from accidental irradiations.

  9. Implication of prostaglandins and histamine h1 and h2 receptors in radiation-induced temperature responses of rats

    SciTech Connect

    Kandasamy, S.B.; Hunt, W.A.; Mickley, G.A .

    1988-01-01

    Exposure of rats to 1-15 Gy cobalt 60 gamma radiation induced hyperthermia, whereas 20-200 Gy induced hypothermia. Exposure either to the head or to the whole body to 10 Gy induced hyperthermia, while body-only exposure produced hypothermia. This observation indicates that radiation-induced fever is a result of a direct effect on the brain. The hyperthermia due to 10 Gy was significantly attenuated by the pre- or post-treatment with a cyclooxgenase inhibitor, indomethacin. Hyperthermia was also altered by the central administration of a mu receptor antagonist naloxone but only at low doses of radiation. These findings suggest that radiation-induced hyperthermia may be mediated through the synthesis and release of prostaglandins in the brain and to a lesser extent to the release of endogenous opioid peptides. The release of histamine acting on H(1) and H(2) receptors may be involved in radiation-induced hypothermia since both the H(1) receptor antagonist, mepyramine, and H(2) receptor antagonist, cimetidine, antagonized the hypothermia. The results of these studies suggested that the release of neurohumoral substances induced by exposure to ionizing radiation is dose dependent and has different consequences on physiological processes such as the regulation of body temperature. Furthermore, the antagonism of radiation-induced hyperthermia by indomethacin may have potential therapeutic implications in the treatment of fever resulting from accidental irradiations.

  10. Theoretical predication of temperature effects on accommodative processes in simulated amyotrophic lateral sclerosis during hypothermia and hyperthermia.

    PubMed

    Stephanova, D I; Kossev, A

    2016-12-01

    Electrotonic potentials allow the accommodative processes to long-lasting subthreshold polarizing stimuli to be assessed. The present study investigates such potentials in previously simulated cases of amyotrophic lateral sclerosis, termed as ALS1, ALS2 and ALS3, respectively, when the temperature is changed during hypothermia ([Formula: see text]C) and hyperthermia ([Formula: see text]C). The ALS cases are modeled as three progressively severe uniform axonal dysfunctions along the human motor nerve fiber which is simulated by our temperature-dependent multi-layered numerical model. The results show that the polarizing electrotonic potentials in the ALS1 case are quite similar to those in the normal case during hypothermia. Their defining currents are caused by the activation of potassium fast (K[Formula: see text]) and slow (K[Formula: see text]) channels in the nodal and internodal axolemma beneath the myelin sheath. Except in the ALS3 case at 20[Formula: see text]C, where the accommodative processes are blocked by depolarizing stimuli, in the ALS2 and ALS3 cases during hypothermia these stimuli activate the classical "transient" Na[Formula: see text] channels in the nodal and internodal axolemma beneath the myelin sheath. And this leads to action potential generations during the early parts of electrotonic responses in all compartments along the fiber length. Only in the ALS3 case after the termination of long-lasting subthreshold hyperpolarizing stimuli, action potential generations are obtained in the late parts of electrotonic potentials along the fiber length. In comparison to the normal case, in the gradually severe ALS cases, the depolarizing electrotonic potentials gradually increase, while the hyperpolarizing electrotonic potentials gradually decrease during hyperthermia. However, the repetitive firings are not obtained in these polarizing electrotonic potentials. The results show that the accommodative processes to depolarizing stimuli in the ALS3 case

  11. Unexpected collapse of healthy newborn infants: risk factors, supervision and hypothermia treatment

    PubMed Central

    Pejovic, Nicolas J; Herlenius, Eric

    2013-01-01

    Aim To determine the occurrence and risk factors of sudden unexpected postnatal collapse (SUPC) in presumably healthy newborn infants. Methods All live-born infants during a 30-month period, in five major delivery wards in Stockholm, were screened, and possible cases of SUPC thoroughly investigated. Infants were ≥35 weeks of gestation, had an Apgar score >8 at 10 min and collapsed within 24 h after birth. Maternal, infant, event characteristics and outcome data were collected. Results Twenty-six cases of SUPC were found among 68 364 live-born infants, an incidence of 38/100 000 live births. Sixteen of these cases of SUPC required resuscitation with ventilation >1 min, and 14 of these remained unexplained (21/100 000). Fifteen of the 26 children were found in a prone position, during skin-to-skin contact, 18 were primipara, and 13 occurred during unsupervised breastfeeding at <2 h of age. Three cases occurred during smart cellular phone use by the mother. Five developed hypoxic–ischaemic encephalopathy (HIE) grade 2, and 4 underwent hypothermia treatment. Twenty-five infants had a favourable neurological outcome. Conclusion SUPC in apparent healthy babies is associated with initial, unsupervised breastfeeding, prone position, primiparity and distractions. Guidelines outlining the appropriate monitoring of newborns and safe early skin-to-skin contact should be implemented. PMID:23551812

  12. Wrist Hypothermia Related to Continuous Work with a Computer Mouse: A Digital Infrared Imaging Pilot Study.

    PubMed

    Reste, Jelena; Zvagule, Tija; Kurjane, Natalja; Martinsone, Zanna; Martinsone, Inese; Seile, Anita; Vanadzins, Ivars

    2015-08-07

    Computer work is characterized by sedentary static workload with low-intensity energy metabolism. The aim of our study was to evaluate the dynamics of skin surface temperature in the hand during prolonged computer mouse work under different ergonomic setups. Digital infrared imaging of the right forearm and wrist was performed during three hours of continuous computer work (measured at the start and every 15 minutes thereafter) in a laboratory with controlled ambient conditions. Four people participated in the study. Three different ergonomic computer mouse setups were tested on three different days (horizontal computer mouse without mouse pad; horizontal computer mouse with mouse pad and padded wrist support; vertical computer mouse without mouse pad). The study revealed a significantly strong negative correlation between the temperature of the dorsal surface of the wrist and time spent working with a computer mouse. Hand skin temperature decreased markedly after one hour of continuous computer mouse work. Vertical computer mouse work preserved more stable and higher temperatures of the wrist (>30 °C), while continuous use of a horizontal mouse for more than two hours caused an extremely low temperature (<28 °C) in distal parts of the hand. The preliminary observational findings indicate the significant effect of the duration and ergonomics of computer mouse work on the development of hand hypothermia.

  13. Early Implementation of THAM for ICP Control: Therapeutic Hypothermia Avoidance and Reduction in Hypertonics/Hyperosmotics.

    PubMed

    Zeiler, F A; Gillman, L M; Teitelbaum, J; West, M

    2014-01-01

    Background. Tromethamine (THAM) has been demonstrated to reduce intracranial pressure (ICP). Early consideration for THAM may reduce the need for other measures for ICP control. Objective. To describe 4 cases of early THAM therapy for ICP control and highlight the potential to avoid TH and paralytics and achieve reduction in sedation and hypertonic/hyperosmotic agent requirements. Methods. We reviewed the charts of 4 patients treated with early THAM for ICP control. Results. We identified 2 patients with aneurysmal subarachnoid hemorrhage (SAH) and 2 with traumatic brain injury (TBI) receiving early THAM for ICP control. The mean time to initiation of THAM therapy was 1.8 days, with a mean duration of 5.3 days. In all patients, after 6 to 12 hours of THAM administration, ICP stability was achieved, with reduction in requirements for hypertonic saline and hyperosmotic agents. There was a relative reduction in mean hourly hypertonic saline requirements of 89.1%, 96.1%, 82.4%, and 97.0% for cases 1, 2, 3, and 4, respectively, comparing pre- to post-THAM administration. Mannitol, therapeutic hypothermia, and paralytics were avoided in all patients. Conclusions. Early administration of THAM for ICP control could potentially lead to the avoidance of other ICP directed therapies. Prospective studies of early THAM administration are warranted.

  14. A mathematical model of respiratory and biothermal dynamics in brain hypothermia treatment.

    PubMed

    Gaohua, Lu; Kimura, Hidenori

    2008-04-01

    Brain hypothermia treatment (BHT) requires proper mechanical ventilation and therapeutic cooling. The cooling strategy for BHT has been mainly discussed in the literature while little information is available on the respiratory management. We first developed a mathematical model that integrates the respiratory and biothermal dynamics to discuss the simultaneous managements of mechanical ventilation and therapeutic cooling. The effect of temperature on the linear approximations of hemoglobin-oxygen dissociation, together with temperature dependency of metabolism, is introduced during modeling to combine the respiratory system with the biothermal system. By comparing its transient behavior with published data, the model is verified qualitatively and then quantitatively. Second, model-based simulation of the current respiratory management in BHT suggests reduction of minute ventilation in reference to cooled brain temperature to stabilize the states of blood and brain oxygenation. Lastly, the relationship between cooling temperature and minute ventilation is approximated by a linear first-order transfer function of static gain 0.61min(-1) degrees C(-1) and time constant 8.9 h, which is used to develop a feedforward control to tune the mechanical ventilator in concert with temperature regulation of the cooling blanket. Discussion of the model encourages further studies that provide direct evidence from clinical experiments.

  15. Severe hypothermia in a patient with spinal cord injury without radiological abnormality

    PubMed Central

    Smith, Travis M; Berk, Alexander S; Upadhyay, Hiten

    2011-01-01

    We report a case of a 64-year-old caucasian male who was transported to the emergency department (ED) after being found unconscious on the side of the road. On arrival to the ED the patient went into ventricular fibrillation and advanced cardiac life support was started at that time. Thirty minutes into the resuscitation, after multiple rounds of code drugs and defibrillation attempts, the patient was found to be severely hypothermic with a rectal temperature of 24.9°C (76.9°F). Through the use of passive and active re-warming measures the patient's temperature increased enough to allow successful cardioversion and stabilization. Within minutes of cardiac stabilization the patient regained consciousness and was able to follow commands, but was found to be paralyzed from the neck down. Subsequent CT scans revealed no acute fractures, subluxations or acute spinal cord injury. This case represents the rare finding of severe hypothermia secondary to occult spinal cord injury. Case report was taken from case at Bayfront Hospital, St. Petersburg, Florida. PMID:21887040

  16. Resveratrol treatment in mice does not elicit the bradycardia and hypothermia associated with calorie restriction.

    PubMed

    Mayers, Jared R; Iliff, Benjamin W; Swoap, Steven J

    2009-04-01

    Dietary supplementation with resveratrol may produce calorie restriction-like effects on metabolic and longevity endpoints in mice. In this study, we sought to determine whether resveratrol treatment elicited other hallmark changes associated with calorie restriction, namely bradycardia and decreased body temperature. We found that during short-term treatment, wild-type mice on a calorie-restricted diet experienced significant decreases in both heart rate and body temperature after only 1 day whereas those receiving resveratrol exhibited no such change after 1 wk. We also used ob/ob mice to study the effects of long-term treatment because previous studies had indicated the therapeutic value of resveratrol against the linked morbidities of obesity and diabetes. After 12 wk, resveratrol treatment had produced no changes in either heart rate or body temperature. Strikingly, and in contrast to previous findings, we found that resveratrol-treated mice had significantly reduced endurance in a treadmill test. Quantitative reverse transcriptase-polymerase chain reaction suggested that a proposed target of resveratrol, Sirt1, was activated in resveratrol-treated ob/ob mice. Thus, we conclude that the bradycardia and hypothermia associated with calorie restriction occur through mechanisms unaffected by the actions of resveratrol and that further studies are needed to examine the differential effects of resveratrol in a leptin-deficient background.

  17. A Survey of Accidental Hypothermia Knowledge among Navy Members in China and the Implications for Training

    PubMed Central

    Li, Shuang; Qiu, Chen; Shi, Wenwen; Huang, Yan; Gui, Li

    2016-01-01

    Objectives: Accidental hypothermia (AH) is a potentially life-threatening condition that can lead to significant morbidity and life-long effects. Navy personnel are always at a greater risk of AH due to frequent outdoor work, wilderness exposure, prolonged immobility and exhaustion. The purpose of the survey was to assess Chinese Navy members’ awareness of AH and to make recommendations with regard to better measures for improving it. Methods: 111 Navy members completed a written questionnaire that was subsequently analyzed. Results: 30.6% of the respondents have experienced AH and 64.9% rated their knowledge of AH as “low” or “none”. Over half of them identified the initial symptom of AH as obvious shivering (69.4%) and apathy (45.0%). As for the aggravate symptoms, 60.9% chose the wrong answer of more obvious shivering instead of the right one—absence of shivering (5.4%). In the case of the treatment of mild AH, more than half of the respondents chose the wrong answers. Conclusions: This study suggests that the basic skills of recognition and treatment of AH are inadequate in the Chinese Navy. Further work is required to develop a systematical, comprehensive and corresponding education method that would promote correct actions during AH. PMID:26978382

  18. Developing sustainable global health technologies: insight from an initiative to address neonatal hypothermia.

    PubMed

    Gupta, Rajesh; Patel, Rajan; Murty, Naganand; Panicker, Rahul; Chen, Jane

    2015-02-01

    Relative to drugs, diagnostics, and vaccines, efforts to develop other global health technologies, such as medical devices, are limited and often focus on the short-term goal of prototype development instead of the long-term goal of a sustainable business model. To develop a medical device to address neonatal hypothermia for use in resource-limited settings, we turned to principles of design theory: (1) define the problem with consideration of appropriate integration into relevant health policies, (2) identify the users of the technology and the scenarios in which the technology would be used, and (3) use a highly iterative product design and development process that incorporates the perspective of the user of the technology at the outset and addresses scalability. In contrast to our initial idea, to create a single device, the process guided us to create two separate devices, both strikingly different from current solutions. We offer insights from our initial experience that may be helpful to others engaging in global health technology development.

  19. Wrist Hypothermia Related to Continuous Work with a Computer Mouse: A Digital Infrared Imaging Pilot Study

    PubMed Central

    Reste, Jelena; Zvagule, Tija; Kurjane, Natalja; Martinsone, Zanna; Martinsone, Inese; Seile, Anita; Vanadzins, Ivars

    2015-01-01

    Computer work is characterized by sedentary static workload with low-intensity energy metabolism. The aim of our study was to evaluate the dynamics of skin surface temperature in the hand during prolonged computer mouse work under different ergonomic setups. Digital infrared imaging of the right forearm and wrist was performed during three hours of continuous computer work (measured at the start and every 15 minutes thereafter) in a laboratory with controlled ambient conditions. Four people participated in the study. Three different ergonomic computer mouse setups were tested on three different days (horizontal computer mouse without mouse pad; horizontal computer mouse with mouse pad and padded wrist support; vertical computer mouse without mouse pad). The study revealed a significantly strong negative correlation between the temperature of the dorsal surface of the wrist and time spent working with a computer mouse. Hand skin temperature decreased markedly after one hour of continuous computer mouse work. Vertical computer mouse work preserved more stable and higher temperatures of the wrist (>30 °C), while continuous use of a horizontal mouse for more than two hours caused an extremely low temperature (<28 °C) in distal parts of the hand. The preliminary observational findings indicate the significant effect of the duration and ergonomics of computer mouse work on the development of hand hypothermia. PMID:26262633

  20. Influence of hypothermia and subsequent rewarming upon leukocyte-endothelial interactions and expression of Junctional-Adhesion-Molecules A and B

    PubMed Central

    Bogert, Nicolai V.; Werner, Isabella; Kornberger, Angela; Meybohm, Patrick; Moritz, Anton; Keller, Till; Stock, Ulrich A.; Beiras-Fernandez, Andres

    2016-01-01

    Patients with risks of ischemic injury, e.g. during circulatory arrest in cardiac surgery, or after resuscitation are subjected to therapeutic hypothermia. For aortic surgery, the body is traditionally cooled down to 18 °C and then rewarmed to body temperature. The role of hypothermia and the subsequent rewarming process on leukocyte-endothelial interactions and expression of junctional-adhesion-molecules is not clarified yet. Thus, we investigated in an in-vitro model the influence of temperature modulation during activation and transendothelial migration of leukocytes through human endothelial cells. Additionally, we investigated the expression of JAMs in the rewarming phase. Exposure to low temperatures alone during transmigration scarcely affects leukocyte extravasation, whereas hypothermia during treatment and transendothelial migration improves leukocyte-endothelial interactions. Rewarming causes a significant up-regulation of transmigration with falling temperatures. JAM-A is significantly modulated during rewarming. Our data suggest that transendothelial migration of leukocytes is not only modulated by cell-activation itself. Activation temperatures and the rewarming process are essential. Continued hypothermia significantly inhibits transendothelial migration, whereas the rewarming process enhances transmigration strongly. The expression of JAMs, especially JAM-A, is strongly modulated during the rewarming process. Endothelial protection prior to warm reperfusion and mild hypothermic conditions reducing the difference between hypothermia and rewarming temperatures should be considered. PMID:26912257

  1. Moderate hypothermia suppresses jugular venous superoxide anion radical, oxidative stress, early inflammation, and endothelial injury in forebrain ischemia/reperfusion rats.

    PubMed

    Koda, Yoichi; Tsuruta, Ryosuke; Fujita, Motoki; Miyauchi, Takashi; Kaneda, Kotaro; Todani, Masaki; Aoki, Tetsuya; Shitara, Masaki; Izumi, Tomonori; Kasaoka, Shunji; Yuasa, Makoto; Maekawa, Tsuyoshi

    2010-01-22

    The aim of this study was to assess the effect of moderate hypothermia (MH) on generation of jugular venous superoxide radical (O2-.), oxidative stress, early inflammation, and endothelial injury in forebrain ischemia/reperfusion (FBI/R) rats. Twenty-one Wistar rats were allocated to a control group (n=7, 37 degrees C), a pre-MH group (n=7, 32 degrees C before ischemia), and a post-MH group (n=7, 32 degrees C after reperfusion). MH was induced before induction of ischemia in the pre-MH group and just after reperfusion in the post-MH group. Forebrain ischemia was induced by occlusion of bilateral common carotid arteries with hemorrhagic hypotension for 10 min, followed by reperfusion. O(2)(-)(.) in the jugular vein was measured from the produced current using a novel O2-. sensor. The O2-. current showed a gradual increase during forebrain ischemia in the control and post-MH groups but was attenuated in the pre-MH group. Following reperfusion, the current showed a marked increase in the control group but was strongly attenuated in the pre- and post-MH groups. Concentrations of malondialdehyde, high-mobility group box 1 (HMGB1) protein, and intercellular adhesion molecule-1 (ICAM-1) in the brain and plasma 120 min after reperfusion in the pre- and post-MH groups were significantly lower than those in the control group, except for plasma HMGB1 in the post-MH group. In conclusion, MH suppressed O2-. measured in the jugular vein, oxidative stress, early inflammation, and endothelial injury in FBI/R rats.

  2. The “Neurovascular Unit approach” to Evaluate Mechanisms of Dysfunctional Autoregulation in Asphyxiated Newborns in the era of Hypothermia Therapy

    PubMed Central

    Chalak, Lina F.; Tarumi, Takashi; Zhang, Rong

    2014-01-01

    Despite improvements in obstetrical and neonatal care, and introduction of hypothermia as a neuroprotective therapy, perinatal brain injury remains a frequent cause of cerebral palsy, mental retardation and epilepsy. The recognition of dysfunction of cerebral autoregulation is essential for a real time measure of efficacy to identify those who are at highest risk for brain injury. This article will focus on the “neurovascular unit” approach to the care of asphyxiated neonates to review 1) potential mechanisms of dysfunctional cerebral blood flow (CBF) regulation, 2) optimal monitoring methodology such as NIRS (near infrared spectroscopy), and TCD (transcutaneous Doppler), and 3) clinical implications of monitoring in the neonatal intensive care setting in asphyxiated newborns undergoing hypothermia and rewarming. Critical knowledge of the functional regulation of the neurovascular unit may lead to improved ability to predict outcomes in real time during hypothermia, as well as differentiate nonresponders who might benefit from additional therapies. PMID:25062804

  3. Electrophysiological functional recovery in a rat model of spinal cord hemisection injury following bone marrow-derived mesenchymal stem cell transplantation under hypothermia.

    PubMed

    Wang, Dong; Zhang, Jianjun

    2012-04-05

    Following successful establishment of a rat model of spinal cord hemisection injury by resecting right spinal cord tissues, bone marrow stem cells were transplanted into the spinal cord lesions via the caudal vein while maintaining rectal temperature at 34 ± 0.5°C for 6 hours (mild hypothermia). Hematoxylin-eosin staining showed that astrocytes gathered around the injury site and formed scars at 4 weeks post-transplantation. Compared with rats transplanted with bone marrow stem cells under normal temperature, rats transplanted with bone marrow stem cells under hypothermia showed increased numbers of proliferating cells (bromodeoxyuridine-positive cells), better recovery of somatosensory-evoked and motor-evoked potentials, greater Basso, Beattie, and Bresnahan locomotor rating scores, and an increased degree of angle in the incline plate test. These findings suggested that hypothermia combined with bone marrow mesenchymal stem cells transplantation effectively promoted electrical conduction and nerve functional repair in a rat model of spinal cord hemisection injury.

  4. Avoiding hypothermia in neonatal pigs: effect of duration of floor heating at different room temperatures.

    PubMed

    Pedersen, L J; Malmkvist, J; Kammersgaard, T; Jørgensen, E

    2013-01-01

    The effect of different farrowing room temperatures (15, 20, or 25°C), combined with floor heating (FH) at the birth site, on the postnatal rectal temperature of pigs, use of creep area, and latency to first colostrum uptake was investigated with 61 litters born by loose-housed sows. Pig rectal temperature was measured at birth, as well as at 0.25, 0.5, 1, 1.5, 2, 3, 4, 12, 24, and 48 h after birth. The drop in rectal temperature from birth to 0.5 h postpartum was less (P<0.05) at room temperature of 25°C compared with 20 and 15°C. Minimum rectal temperature was less (P<0.001) at 15°C than either 20 or 25°C, and the time it took for rectal temperature to increase above 37°C was longer (P<0.05) when room temperature was 15°C than 20 and 25°C. Rectal temperatures at 24 (P<0.001) and 48 h (P<0.05) postpartum were also lower at room temperature of 15°C than 20 and 25°C. Duration of FH (12 or 48 h) did not influence (P>0.28) the rectal temperature at 24 or 48 h after birth. More pigs used the creep area 12 to 60 h after birth of the first pig at a room temperature of 15°C with 12 h FH compared with all other treatments. During the latter part of this period, more pigs stayed in the creep area also at 20°C with 12 h FH. After 60 h, more pigs (P<0.01) used the creep area at low compared with high room temperatures (15°C>20°C>25°C). Odds ratio of pigs dying before they had suckled was 6.8 times greater (P=0.03) at 15 than 25°C (95% CI of 1.3 to 35.5), whereas the odds ratio of dying during the first 7 d was 1.6 greater (P=0.05) for 48 vs. 12 h of FH (95% CI of 1.0 to 2.57), mainly due to more pigs being crushed. In conclusion, FH for 48 h was no more favorable than 12 h for pigs because the risk of hypothermia was equal in the 2 treatments, and the risk of dying increased with the longer FH duration. Increasing the room temperature to 25°C reduced hypothermia and the risk of pigs dying before colostrum intake.

  5. Changes in cardiac thrombomodulin and heat shock transcription factor 1 expression and peripheral thrombomodulin and catecholamines during hypothermia in rats.

    PubMed

    Kaija, Helena; Pakanen, Lasse; Uusitalo, Jenni; Nikkilä, Suvi; Kortelainen, Marja-Leena; Porvari, Katja Sofia

    2014-12-01

    Effects of hypothermia and rewarming on thrombomodulin, catecholamines and heat shock transcription factor 1 (HSF1) were studied in rats. The aims of this study were to clarify whether cold stress, under anesthesia, is sufficient to change levels of thrombomodulin in healthy endothelium and in the circulation and whether adrenaline, noradrenaline and HSF1 could act as regulators in the process. Rats were divided into control, mild hypothermia (2 and 4.5 hours at + 21 °C; MH1, MH2), severe hypothermia (2 and 4.5 h at + 10 °C; SH1, SH2) and two rewarming groups (2 h at + 10 °C followed by 2 h at + 21 °C or 3 h at + 28 °C; SHW1, SHW2) (n = 15/group, except n = 6 in MH1). Fentanyl-fluanisone-midazolam was used as anesthetic. Low levels of thrombomodulin in plasma and myocardial arterioles/venules measured by ELISA and immunohistochemistry were associated with significant increase of thrombomodulin transcript level in SH1 rats analyzed by quantitative PCR. Plasma adrenaline correlated negatively with the relative amount of myocardial thrombomodulin transcripts and positively with plasma thrombomodulin in SH. Transcript levels of thrombomodulin and HSF1 correlated strongly (r = 0.83; p < 0.001) in SH. Plasma/urine ratio of thrombomodulin and plasma adrenaline (r = 0.87; p = 0.005) or noradrenaline (r = 0.78; p = 0.023) were strongly correlated in SHW1 rats. Hence, cellular and soluble levels of thrombomodulin are modified by cold stress in healthy rats, possibly via catecholamines and HSF1.

  6. Galectin-3 expression in delayed neuronal death of hippocampal CA1 following transient forebrain ischemia, and its inhibition by hypothermia.

    PubMed

    Satoh, Kunio; Niwa, Masayuki; Goda, Wael; Binh, Nguyen Huy; Nakashima, Masaya; Takamatsu, Manabu; Hara, Akira

    2011-03-25

    The ischemic damage in the hippocampal CA1 sector following transient ischemia, delayed neuronal death, is a typical apoptosis, but the mechanism underlying the delayed neuronal death is still far from fully understood. Galectin-3 is a β-galactosidase-binding lectin which is important in cell proliferation and apoptotic regulation. Galectin-3 is expressed by microglial cells in experimental models of adult stroke. It has been reported that activated microglial cells are widely observed in the brain, including in the hippocampal CA1 region after transient ischemic insult. In the present study, time course expression of galectin-3 following transient forebrain ischemia in gerbils was examined by immunohistochemistry, combined with Iba-1 immunostaining (a specific microglial cell marker), hematoxylin and eosin staining (for morphological observation), and in situ terminal dUTP-biotin nick end labeling of DNA fragments method (for determination of cell death). Following transient ischemia, we observed a transient increase of galectin-3 expression in CA1 region, which was maximal 96h after reperfusion. Galectin-3 expression was predominately localized within CA1 region and observed only in cells which expressed Iba-1. The galectin-3-positive microglial cells emerge after the onset of neuronal cell damage. Expressions of galectin-3 and Iba-1 were strongly reduced by hypothermia during ischemic insult. Prevention of galectin-3 and Iba-1 expression in microglia by hypothermia has led us to propose that hypothermia either inhibits microglial activation or prevents delayed neuronal death itself. Our results indicate that galectin-3 might exert its effect by modulating the neuronal damage in delayed neuronal death.

  7. Value of electroencephalographic monitoring in newborns with hypoxic-ischemic encephalopathy treated with hypothermia

    PubMed Central

    Elshorbagy, Hatem Hamed; Azab, Ahmed A.; Kamal, Naglaa M.; Barseem, Naglaa Fathy; Bassiouny, Mohamed M.; Elsayed, Mostafa A.; Elkhouly, Tohamy H.

    2016-01-01

    Background: The values of electroencephalography (EEG) in neonatal hypoxic-ischemic encephalopathy (HIE) during therapeutic hypothermia (TH) are still uncertain. Aims: The aim of this study is to detect EEG background, the prevalence of seizures during cooling, and to determine different EEG patterns that can predict brain injury in magnetic resonance imaging (MRI). Patients and Methods: Thirty-nine newborns with HIE were subjected to TH. Continuous monitoring by video-EEG was carried out throughout cooling and during rewarming. MRI was done for all newborns after rewarming. The predictive value of EEG background for MRI brain injury was evaluated at 6-h intervals during cooling and rewarming. Results: At all-time intervals, normal EEG was associated with no or mild MRI brain injury. At the beginning of cooling, normal background was more predictive of a favorable MRI outcome than at later time points. After 24 h of monitoring, diffuse burst suppression and depressed patterns had the greatest prognostic value. In most patients, a discontinuous pattern was not associated with poor prognosis. Thirty-one percent developed electrical seizures, and 8% developed status epilepticus. Seizures were subclinical in 42%. There is a significant association between duration of seizure patterns detected on the EEG and severity of brain injury on MRI. Conclusions: Continuous EEG monitoring in newborns with HIE under cooling has a prognostic value about early MRI brain injury and identifies electrographic seizures, approximately 50% of which are subclinical. Treatment of clinical and subclinical seizure results in a reduction of the total duration of seizure pattern supports the hypothesis that subclinical seizures should be treated. PMID:28217152

  8. Immediate hypothermia reduces cardiac troponin I after hypoxic-ischemic encephalopathy in newborn pigs.

    PubMed

    Liu, Xun; Tooley, James; Løberg, Else M; Suleiman, M Saadeh; Thoresen, Marianne

    2011-10-01

    Neonatal hypoxic-ischemic encephalopathy (HIE) is a clinically defined neurological condition after lack of oxygen and often associated with cardiac dysfunction in term infants. Therapeutic hypothermia (HT) after birth is neuroprotective in infants with HIE. However, it is not known whether HT is also cardioprotective. Four newborn pigs were used in the pilot study and a further 18 newborn pigs [randomly assigned to 72 h normothermia (NT) or 24 h HT followed by 48 h NT] were subjected to global HIE insults. Serum cTnI was measured before and post the HIE insult. Blood pressure, inotropic support, blood gases, and heart rate (HR) were recorded throughout. Cardiac pathology was assessed from histological sections. Cooling reduced serum cTnI levels significantly in HT pigs by 6 h (NT, 1.36 ± 0.67; HT, 0.34 ± 0.23 ng/mL; p = 0.0009). After rewarming, from 24 to 30 h postinsult, HR and cTnI increased in the HT group; from HR[24 h] = 117 ± 22 to HR[30 h] = 218 ± 32 beats/min (p = 0.0002) and from cTnI[24 h] = 0.23 ± 0.12 to cTnI[30 h] = 0.65 ± 0.53 ng/mL, (p = 0.05). There were fewer ischemic lesions on cardiac examination (37%) in the HT group compared with the NT group (70%). HT (24 h) pigs did not have the postinsult cTnI increase seen in NT-treated pigs. There was a trend that HT improved cardiac pathology in this 3-d survival model.

  9. Feasibility Study Evaluating Therapeutic Hypothermia for Refractory Status Epilepticus in Children.

    PubMed

    Buttram, Sandra D W; Au, Alicia K; Koch, Joshua; Lidsky, Karen; McBain, Kristin; O'Brien, Nicole; Zielinski, Brandon A; Bell, Michael J

    2015-12-01

    Pediatric refractory status epilepticus (RSE) is a neurological emergency with significant morbidity and mortality, which lacks consensus regarding diagnosis and treatment(s). Therapeutic hypothermia (TH) is an effective treatment for RSE in preclinical models and small series. In addition, TH is a standard care for adults after cardiac arrest and neonates with hypoxic-ischemic encephalopathy. The purpose of this study was to identify the feasibility of a study of pediatric RSE within a research group (Pediatric Neurocritical Care Research Group [PNCRG]). Pediatric intensive care unit (PICU) admissions at seven centers were prospectively screened from October 2012 to July 2013 for RSE. Experts within the PNCRG estimated that clinicians would be unwilling to enroll a child, unless the child required at least two different antiepileptic medications and a continuous infusion of another antiepileptic medication with ongoing electrographic seizure activity for ≥2 hours after continuous infusion initiation. Data for children meeting the above inclusion criteria were collected, including the etiology of RSE, history of epilepsy, and maximum dose of continuous antiepileptic infusions. There were 8113 PICU admissions over a cumulative 52 months (October 2012-July 2013) at seven centers. Of these, 69 (0.85%) children met inclusion criteria. Twenty children were excluded due to acute diagnoses affected by TH, contraindications to TH, or lack of commitment to aggressive therapies. Sixteen patients had seizure cessation within 2 hours, resulting in 33 patients who had inadequate seizure control after 2 hours and a continuous antiepileptic infusion. Midazolam (21/33, 64%) and pentobarbital (5/33, 15%) were the most common infusions with a wide maximum dose range. More than one infusion was required for seizure control in four patients. There are substantial numbers of subjects at clinical sites within the PNCRG with RSE that would meet the proposed inclusion criteria for a

  10. Hypothermia decreased the expression of heat shock proteins in neonatal rat model of hypoxic ischemic encephalopathy.

    PubMed

    Lee, Byong Sop; Jung, Euiseok; Lee, Yeonjoo; Chung, Sung-Hoon

    2017-03-11

    Hypothermia (HT) is a well-established neuroprotective strategy against neonatal hypoxic ischemic encephalopathy (HIE). The overexpression of heat shock proteins (HSP) has been shown to provide neuroprotection in animal models of stroke. We aimed to investigate the effect of HT on HSP70 and HSP27 expression in a neonatal rat model of HIE. Seven-day-old rat pups were exposed to hypoxia for 90 min to establish the Rice-Vannucci model and were assigned to the following four groups: hypoxic injury (HI)-normothermia (NT, 36 °C), HI-HT (30 °C), sham-NT, and sham-HT. After temperature intervention for 24 h, the mRNA and protein expression of HSP70 and HSP27 were measured. The association between HSP expression and brain injury severity was also evaluated. The brain infarct size was significantly smaller in the HI-HT group than in the HI-NT group. The mRNA and protein expression of both HSPs were significantly greater in the two HI groups, compared to those in the two sham groups. Moreover, among the rat pups subjected to HI, HT significantly reduced the mRNA and protein expression of both HSPs. The mRNA expression level of the HSPs was proportional to the brain injury severity. Post-ischemic HT, i.e., a cold shock attenuated the expression of HSP70 and HSP27 in a neonatal rat model of HIE. Our study suggests that neither HSP70 nor HSP27 expression is involved in the neuroprotective mechanism through which prolonged HT protects against neonatal HIE.

  11. Adherence to Hypothermia Guidelines: A French Multicenter Study of Fullterm Neonates

    PubMed Central

    Chevallier, Marie; Ego, Anne; Cans, Christine; Debillon, Thierry

    2013-01-01

    Aim The objective of this study was to describe the French practice of hypothermia treatment (HT) in full-term newborns with hypoxic-ischemic encephalopathy (HIE) and to analyze the deviations from the guidelines of the French Society of Neonatology. Materials and Methods From May 2010 to March 2012 we recorded all cases of HIE treated by HT in a French national database. The population was divided into three groups, "optimal HT" (OHT), “late HT” (LHT) and “non-indicated” HT (NIHT), according to the guidelines. Results Of the 311 newborns registered in the database and having HT, 65% were classified in the OHT group, 22% and 13% in the LHT and NIHT groups respectively. The severity of asphyxia and HIE were comparable between newborns with OHT and LHT, apart from EEG. HT was initiated at a mean time of 12 hours of life in the LHT group. An acute obstetrical event was more likely to be identified among newborns with LHT (46%), compared to OHT (34%) and NIHT (22%). There was a gradation in the rate of complications from the NIHT group (29%) to the LHT (38%) group and the OHT group (52%). Despite an insignificant difference in the rates of death or abnormal neurological examination at discharge, nearly 60% of newborns in the OHT group had an MRI showing abnormalities, compared to 44% and 49% in the LHT and NIHT groups respectively. Conclusion The conduct of the HT for HIE newborns is not consistent with French guidelines for 35% of newborns, 22% being explained by an excessive delay in the start of HT, 13% by the lack of adherence to the clinical indications. This first report illustrates the difficulties in implementing guidelines for HT and should argue for an optimization of perinatal care for HIE. PMID:24391817

  12. Psychotropic drug-associated electrocardiographic presentation of diffuse J-waves in hypothermia: case report and literature review.

    PubMed

    Kataoka, Hajime; Kajiwara, Hirofumi; Yano, Eiji

    2016-06-01

    The use of psychotropic drugs is often associated with electrocardiographic (ECG) QT-interval prolongation, but there are few reports of J-waves. This report describes the case of a schizophrenic patient under treatment with several psychotropic drugs (olanzapine, valproate, and flunitrazepam), in whom ECG J-waves diffusely appeared during a hypothermic episode. We further performed a literature review of psychotropic drug-related J-waves in hypothermia. The present case highlights the importance of recognizing psychotropic drug-related ECG J-waves on an early warning sign to ensure appropriate monitoring and/or treatment for possible life-threatening side effects of such medications.

  13. European society of intensive care medicine study of therapeutic hypothermia (32-35°C) for intracranial pressure reduction after traumatic brain injury (the Eurotherm3235Trial)

    PubMed Central

    2011-01-01

    Background Traumatic brain injury is a major cause of death and severe disability worldwide with 1,000,000 hospital admissions per annum throughout the European Union. Therapeutic hypothermia to reduce intracranial hypertension may improve patient outcome but key issues are length of hypothermia treatment and speed of re-warming. A recent meta-analysis showed improved outcome when hypothermia was continued for between 48 hours and 5 days and patients were re-warmed slowly (1°C/4 hours). Previous experience with cooling also appears to be important if complications, which may outweigh the benefits of hypothermia, are to be avoided. Methods/design This is a pragmatic, multi-centre randomised controlled trial examining the effects of hypothermia 32-35°C, titrated to reduce intracranial pressure <20 mmHg, on morbidity and mortality 6 months after traumatic brain injury. The study aims to recruit 1800 patients over 41 months. Enrolment started in April 2010. Participants are randomised to either standard care or standard care with titrated therapeutic hypothermia. Hypothermia is initiated with 20-30 ml/kg of intravenous, refrigerated 0.9% saline and maintained using each centre's usual cooling technique. There is a guideline for detection and treatment of shivering in the intervention group. Hypothermia is maintained for at least 48 hours in the treatment group and continued for as long as is necessary to maintain intracranial pressure <20 mmHg. Intracranial hypertension is defined as an intracranial pressure >20 mmHg in accordance with the Brain Trauma Foundation Guidelines, 2007. Discussion The Eurotherm3235Trial is the most important clinical trial in critical care ever conceived by European intensive care medicine, because it was launched and funded by the European Society of Intensive Care Medicine and will be the largest non-commercial randomised controlled trial due to the substantial number of centres required to deliver the target number of patients. It

  14. A case of transient hypothermia after trans-lamina terminalis and third ventricle clipping of an extremely high-position basilar tip aneurysm

    PubMed Central

    Ikawa, Fusao; Hamasaki, Osamu; Kurokawa, Yasuharu; Yonezawa, Ushio; Kurisu, Kaoru

    2015-01-01

    Reports on the trans-lamina terminalis and trans-third ventricular approach are rare. The risk associated with this approach is unknown. After an unsuccessful endovascular surgery, we performed direct surgical clipping via the third ventricle on a 78-year-old woman presenting with an extremely high-positioned, ruptured basilar tip aneurysm. She experienced transient hypothermia for 5 days, and it was considered that this was due to hypothalamic dysfunction. It is necessary to recognize that there is the potential for hypothermia after surgery via the lamina terminalis and third ventricle, even though the mechanisms of hypothalamic thermoregulation are still unclear. PMID:27489684

  15. Methods for study of cardiovascular adaptation of small laboratory animals during exposure to altered gravity. [hypothermia for cardiovascular control and cancer therapy

    NASA Technical Reports Server (NTRS)

    Popovic, V.

    1973-01-01

    Several new techniques are reported for studying cardiovascular circulation in small laboratory animals kept in metabolic chambers. Chronical cannulation, miniaturized membrane type heart-lung machines, a prototype walking chamber, and a fluorocarbon immersion method to simulate weightlessness are outlined. Differential hypothermia work on rat cancers provides localized embedding of radionuclides and other chemotherapeutical agents in tumors and increases at the same time blood circulation through the warmed tumor as compared to the rest of the cold body. Some successful clinical applications of combined chemotherapy and differential hypothermia in skin cancer, mammary tumors, and brain gliomas are described.

  16. Role of hypothermia in the mechanism of protection against serotonergic toxicity. II. Experiments with methamphetamine, p-chloroamphetamine, fenfluramine, dizocilpine and dextromethorphan.

    PubMed

    Farfel, G M; Seiden, L S

    1995-02-01

    Several amphetamine analogs, when administered in high-dose regimens, have been shown to cause long-lasting depletions of central serotonin (5-HT), which are indicative of neuronal toxicity. These depletions and the resulting toxicity can be attenuated pharmacologically or by lowering ambient temperature. The noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist dizocilpine (DZ) blocks depletion of 5-HT induced by methamphetamine (METH) and p-chloroamphetamine (PCA), but not fenfluramine (FEN). This study investigated whether the effects of DZ and another calcium channel antagonist, dextromethorphan (DEX), are due to induction of hypothermia. Male Sprague-Dawley rats were injected with either saline (SAL), DZ (1 or 2 injections of 2.5 mg/kg), or DEX (75.0 mg/kg) followed by either SAL, METH (4 injections of 10.0 mg/kg), PCA (1 injection of 10.0 mg/kg) or FEN (2 or 4 injections of 12.5 mg/kg). Core body temperature (TEMP) was monitored for 4 h or longer with radiotelemetry. Base-line TEMP was between 37.0 and 37.6 degrees C. SAL/METH caused a significant increase in TEMP which peaked at 40.8 +/- 0.50 degrees C after the last injection. Coadministration of DZ with METH caused TEMP to decrease to 33.8 +/- 0.30 degrees C within 2 h of the first injection and lasting more than 3 h, and protected against depletion of 5-HT. SAL/PCA caused a small increase in TEMP to 37.7 +/- 0.36 degrees C, whereas coadministration of DZ with PCA decreased TEMP to 35.2 +/- 0.50 degrees C, lasting 2 h, in a dose regimen which has been shown to be neuroprotective.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Therapeutic hypothermia for neonatal encephalopathy: a report from the first 3 years of the Baby Cooling Registry of Japan

    PubMed Central

    Tsuda, Kennosuke; Mukai, Takeo; Iwata, Sachiko; Shibasaki, Jun; Tokuhisa, Takuya; Ioroi, Tomoaki; Sano, Hiroyuki; Yutaka, Nanae; Takahashi, Akihito; Takeuchi, Akihito; Takenouchi, Toshiki; Araki, Yuko; Sobajima, Hisanori; Tamura, Masanori; Hosono, Shigeharu; Nabetani, Makoto; Iwata, Osuke; Adachi, Hiroyuki; Aiba, Satoru; Akiyoshi, Shinnosuke; Amizuka, Takasuke; Aoki, Mikihiro; Arai, Hirokazu; Arai, Junichi; Asanuma, Hideomi; Baba, Atsushi; Bonno, Motoki; Daimon, Yusuke; Egashira, Tomoko; Fukuhara, Rie; Fukushima, Naoki; Futamura, Masahide; Harada, Sayaka; Hattori, Tsukasa; Henmi, Nobuhide; Hiroma, Takehiko; Hisano, Tadashi; Ieda, Kuniko; Iida, Koichi; Iijima, Shigeo; Imai, Ken; Imamura, Takashi; Inoue, Shinkai; Ishiguro, Akio; Suzuki, Keiji; Ishii, Tsutomu; Ito, Takashi; Iwai, Masanori; Iwataki, Shinnichiro; Jinnai, Wataru; Kai, Akihiko; Kanbe, Taro; Kinoshita, Masahiro; Kanda, Hiroshi; Kaneko, Masatoshi; Kawase, Akihiko; Kawato, Hitoshi; Kida, Yoshikazu; Kihara, Minako; Kitano, Hiroyuki; Kishigami, Makoto; Shibata, Naoaki; Kito, Osamu; Kobayashi, Akira; Kohno, Yoshinori; Kokubo, Minoru; Kondo, Masatoshi; Konishi, Eri; Kugo, Masaki; Kouwaki, Masanori; Kumagai, Takeshi; Kusaka, Takashi; Kusuda, Takeshi; Maeda, Tomoki; Maede, Yoshinobu; Maji, Tomoaki; Makiya, Tomoko; Maruyama, Kennichi; Masunaga, Ken; Matsumoto, Atsushi; Matsumoto, Hiroshi; Matsumoto, Naoko; Mima, Aya; Minagawa, Kyoko; Minosaki, Yoshihiro; Minowa, Hideki; Miura, Mazumi; Miyata, Masafumi; Miyazono, Yayoi; Mizumoto, Hiroshi; Mori, Kazuhiro; Morioka, Ichiro; Morisawa, Takeshi; Nagaya, Ken; Nagayama, Yoshihisa; Naito, Atsushi; Nakamura, Kenji; Nakamura, Makoto; Nakao, Atsushi; Nakao, Hideto; Nakazawa, Yusuke; Nishimura, Yutaka; Nishizaki, Naoto; Nosaka, Kazuhiko; Nozaki, Masatoshi; Ochiai, Masayuki; Ohashi, Atsushi; Ohki, Shigeru; Omori, Isaku; Osone, Yoshiteru; Saito, Junko; Sato, Yoshiaki; Sato, Yoshitake; Seki, Kazuo; Shirakawa, Yoshitsugu; Shiro, Hiroyuki; Suzumura, Hiroshi; Takahashi, Ritsuko; Takahata, Yasushi; Taki, Atsuko; Tanaka, Taihei; Tateishi, Itaru; Tsunei, Mikio; Usuda, Touhei; Yada, Yukari; Yamamoto, Junko; Yamamoto, Masahito; Yoda, Hitoshi; Yokoi, Akiko; Yoshida, Shinobu; Yoshida, Taketoshi; Yoshida, Tomohide; Yoshikawa, Kayo

    2017-01-01

    Therapeutic hypothermia is recommended for moderate and severe neonatal encephalopathy, but is being applied to a wider range of neonates than originally envisaged. To examine the clinical use of therapeutic hypothermia, data collected during the first 3 years (2012–2014) of the Baby Cooling Registry of Japan were analysed. Of 485 cooled neonates, 96.5% were ≥36 weeks gestation and 99.4% weighed ≥1,800 g. Severe acidosis (pH < 7 or base deficit ≥16 mmol/L) was present in 68.9%, and 96.7% required resuscitation for >10 min. Stage II/III encephalopathy was evident in 88.3%; hypotonia, seizures and abnormal amplitude-integrated electroencephalogram were observed in the majority of the remainder. In-hospital mortality was 2.7%; 90.7% were discharged home. Apgar scores and severity of acidosis/encephalopathy did not change over time. The time to reach the target temperature was shorter in 2014 than in 2012. The proportion undergoing whole-body cooling rose from 45.4% to 81.6%, while selective head cooling fell over time. Mortality, duration of mechanical ventilation and requirement for tube feeding at discharge remained unchanged. Adherence to standard cooling protocols was high throughout, with a consistent trend towards cooling being achieved more promptly. The mortality rate of cooled neonates was considerably lower than that reported in previous studies. PMID:28051172

  18. Optimal control of inspired perfluorocarbon temperature for induction of hypothermia by total liquid ventilation in juvenile lamb model.

    PubMed

    Nadeau, Mathieu; Sage, Michael; Praud, Jean-Paul; Tissier, Renaud; Walti, Herve; Micheau, Philippe; Nadeau, Mathieu; Sage, Michael; Praud, Jean-Paul; Tissier, Renaud; Walti, Herve; Micheau, Philippe; Sage, Michael; Micheau, Philippe; Praud, Jean-Paul; Nadeau, Mathieu; Walti, Herve; Tissier, Renaud

    2016-08-01

    Mild hypothermia is well known for its therapeutic value in cardio- and neuroprotection. Many recent experimental studies have shown that the swiftness of the cooling offered by total liquid ventilation (TLV) holds great promise in achieving maximal therapeutic effect. TLV is an emerging ventilation technique in which the lungs are filled with breathable liquids, namely perfluorocarbons (PFCs). A liquid ventilator ensures subject ventilation by periodically renewing a volume of oxygenated, CO2-free and temperature-controlled breathable PFC. The substantial difference between breathing air and liquid is related to the fact that PFCs have over 500 times the volumetric thermal capacity of air 100% relative humidity. The PFC-filled lungs thus turn into an efficient heat exchanger with pulmonary circulation. The objective of the present study was to compute a posteriori the optimal inspired PFC temperature for ultrafast induction of mild hypothermia by TLV in a juvenile lamb experimentation using direct optimal control. The continuous time model and the discretized cycle-by-cycle model are presented. The control objectives of the direct optimal control are also presented and the results are compared with experimental data in order to validate the improved control performances. The computed direct optimal control showed that the inspired PFC temperature command can be improved to avoid temperature undershoots without altering the cooling performances.

  19. First Use of a New Device for Administration of Buspirone and Acetaminophen to Suppress Shivering During Therapeutic Hypothermia

    PubMed Central

    Parker, Braden; Wesselhoff, Kelly; Lyons, Neal; Kulstad, Erik

    2016-01-01

    Therapeutic hypothermia or targeted temperature management has been used after cardiac arrest to improve neurological outcomes and mortality. However, a side effect of temperature modulation is a centrally mediated shivering response. The Columbia Anti-Shivering Protocol sets up a systematic method of intravenous (IV) and oral medication escalation to suppress this response and preserve the benefits of this therapy. We present the case of a 59-year-old male who began shivering after therapeutic hypothermia for cardiac arrest, leading to a persistent rise in core temperature despite adequate sedation. He was also found to have gastric contents similar to coffee grounds through nasogastric tube suction. The shivering was effectively suppressed and the rising core temperature plateaued using rectal acetaminophen and buspirone administered by means of a novel device, the Macy Catheter. Also, when used in conjunction with other protocol-driven medications, the patient was able to achieve a core temperature of 33°C. The Macy Catheter appears to be a useful approach to rectally administer buspirone and acetaminophen, using an easy-to-place, nonsterile atraumatic device that requires no radiographic confirmation of placement. PMID:26807775

  20. Limited short-term prognostic utility of cerebral NIRS during neonatal therapeutic hypothermia

    PubMed Central

    Thelen, Brian J.; Bapuraj, Jayapalli R.; Burns, Joseph W.; Swenson, Aaron W.; Christensen, Mary K.; Wiggins, Stephanie A.; Barks, John D.E.

    2013-01-01

    Objective: We evaluated the utility of amplitude-integrated EEG (aEEG) and regional oxygen saturation (rSO2) measured using near-infrared spectroscopy (NIRS) for short-term outcome prediction in neonates with hypoxic ischemic encephalopathy (HIE) treated with therapeutic hypothermia. Methods: Neonates with HIE were monitored with dual-channel aEEG, bilateral cerebral NIRS, and systemic NIRS throughout cooling and rewarming. The short-term outcome measure was a composite of neurologic examination and brain MRI scores at 7 to 10 days. Multiple regression models were developed to assess NIRS and aEEG recorded during the 6 hours before rewarming and the 6-hour rewarming period as predictors of short-term outcome. Results: Twenty-one infants, mean gestational age 38.8 ± 1.6 weeks, median 10-minute Apgar score 4 (range 0–8), and mean initial pH 6.92 ± 0.19, were enrolled. Before rewarming, the most parsimonious model included 4 parameters (adjusted R2 = 0.59; p = 0.006): lower values of systemic rSO2 variability (p = 0.004), aEEG bandwidth variability (p = 0.019), and mean aEEG upper margin (p = 0.006), combined with higher mean aEEG bandwidth (worse discontinuity; p = 0.013), predicted worse short-term outcome. During rewarming, lower systemic rSO2 variability (p = 0.007) and depressed aEEG lower margin (p = 0.034) were associated with worse outcome (model-adjusted R2 = 0.49; p = 0.005). Cerebral NIRS data did not contribute to either model. Conclusions: During day 3 of cooling and during rewarming, loss of physiologic variability (by systemic NIRS) and invariant, discontinuous aEEG patterns predict poor short-term outcome in neonates with HIE. These parameters, but not cerebral NIRS, may be useful to identify infants suitable for studies of adjuvant neuroprotective therapies or modification of the duration of cooling and/or rewarming. PMID:23771483

  1. Rapid Induction of Therapeutic Hypothermia Using Transnasal High Flow Dry Air.

    PubMed

    Chava, Raghuram; Zviman, Menekhem; Raghavan, Madhavan Srinivas; Halperin, Henry; Maqbool, Farhan; Geocadin, Romergryko; Quinones-Hinojosa, Alfredo; Kolandaivelu, Aravindan; Rosen, Benjamin A; Tandri, Harikrishna

    2017-03-01

    Early induction of therapeutic hypothermia (TH) is recommended in out-of-hospital cardiac arrest (CA); however, currently no reliable methods exist to initiate cooling. We investigated the effect of high flow transnasal dry air on brain and body temperatures in adult porcine animals. Adult porcine animals (n = 23) under general anesthesia were subject to high flow of transnasal dry air. Mouth was kept open to create a unidirectional airflow, in through the nostrils and out through the mouth. Brain, internal jugular, and aortic temperatures were recorded. The effect of varying airflow rate and the air humidity (0% or 100%) on the temperature profiles were recorded. The degree of brain cooling was measured as the differential temperature from baseline. A 10-minute exposure of high flow dry air caused rapid cooling of brain and gradual cooling of the jugular and the aortic temperatures in all animals. The degree of brain cooling was flow dependent and significantly higher at higher airflow rates (0.8°C ± 0.3°C, 1.03°C ± 0.6°C, and 1.3°C ± 0.7°C for 20, 40, and 80 L, respectively, p < 0.05 for all comparisons). Air temperature had minimal effect on the brain cooling over 10 minutes with similar decrease in temperature at 4°C and 30°C. At a constant flow rate (40 LPM) and temperature, the degree of cooling over 10 minutes during dry air exposure was significantly higher compared to humid air (100% saturation) (1.22°C ± 0.35°C vs. 0.21°C ± 0.12°C, p < 0.001). High flow transnasal dry air causes flow dependent cooling of the brain and the core temperatures in intubated porcine animals. The mechanism of cooling appears to be evaporation of nasal mucus as cooling is mitigated by humidifying the air. This mechanism may be exploited to initiate TH in CA.

  2. The Next Generation of Cold Immersion Dry Suit Design Evolution for Hypothermia Prevention

    NASA Technical Reports Server (NTRS)

    Galofaro, Joel

    2013-01-01

    This new utility patent is an active design that relies on the lung's role as an organic heat exchanger for providing deep body core heating of air. It is based on the fact that the greatest heat loss mechanism for an insulated human body immersed in a cold water environment is due to heat loss through respiration. This innovation successfully merges two existing technologies (cold immersion suit and existing valve technologies) to produce a new product that helps prevent against the onset of hypothermia at sea. During normal operations, a human maintains an approximate body temperature of [98.6 F (37 C)]. A mechanism was developed to recover the warm temperature from the body and reticulate it in a survival suit. The primary intention is to develop an encompassing systems design that can both easily and cost effectively be integrated in all existing currently manufactured cold water survival suits, and as such, it should be noted that the cold water immersion suit is only used as a framework or tool for laying out the required design elements. At the heart of the suit is the Warm Air Recovery (WAR) system, which relies on a single, large Main Purge Valve (MPV) and secondary Purge Valves (PV) to operate. The main purge valve has a thin membrane, which is normally closed, and acts as a one-way check valve. When warm air is expelled from the lungs, it causes the main purge valve to open. Air forced from the MPV is dumped directly into the suit, thereby providing warmth to the torso, legs, and arms. A slight positive over-pressure in the suit causes warm waste air (or water if the suit is punctured) to be safely vented into the sea through large PVs located at the bottom of each arm and leg. The secondary purge valves act to prevent the buildup of large concentrations of CO2 gas and help guard against asphyxia. It is noted that the MPV causes the inhalation and exhalation cycles to be completely isolated from one another in the current suit design.

  3. A recommended early goal-directed management guideline for the prevention of hypothermia-related transfusion, morbidity, and mortality in severely injured trauma patients.

    PubMed

    Perlman, Ryan; Callum, Jeannie; Laflamme, Claude; Tien, Homer; Nascimento, Barto; Beckett, Andrew; Alam, Asim

    2016-04-20

    Hypothermia is present in up to two-thirds of patients with severe injury, although it is often disregarded during the initial resuscitation. Studies have revealed that hypothermia is associated with mortality in a large percentage of trauma cases when the patient's temperature is below 32 °C. Risk factors include the severity of injury, wet clothing, low transport unit temperature, use of anesthesia, and prolonged surgery. Fortunately, associated coagulation disorders have been shown to completely resolve with aggressive warming. Selected passive and active warming techniques can be applied in damage control resuscitation. While treatment guidelines exist for acidosis and bleeding, there is no evidence-based approach to managing hypothermia in trauma patients. We synthesized a goal-directed algorithm for warming the severely injured patient that can be directly incorporated into current Advanced Trauma Life Support guidelines. This involves the early use of warming blankets and removal of wet clothing in the prehospital phase followed by aggressive rewarming on arrival at the hospital if the patient's injuries require damage control therapy. Future research in hypothermia management should concentrate on applying this treatment algorithm and should evaluate its influence on patient outcomes. This treatment strategy may help to reduce blood loss and improve morbidity and mortality in this population of patients.

  4. Efficacy of the blizzard blanket or blizzard blanket plus thermal angel in preventing hypothermia in a hemorrhagic shock victim (Sus scrofa) under operational conditions.

    PubMed

    Bridges, Elizabeth; Schmelz, Joseph; Evers, Karen

    2007-01-01

    The prevention of hypothermia in military casualties under field conditions is challenging. The efficacy of a baffled reflective Blanket (Blizzard Blanket), a portable intravenous fluid warmer (Thermal Angel), and wool Blankets (control) in preventing hypothermia was tested under military field conditions in a swine hemorrhagic shock model. Fifteen pigs were bled at 10 degrees C. After 45 minutes, Hextend was administered (groups 1 and 3, at 10 degrees C; group 2, via Thermal Angel); groups 2 and 3 were encircled with a Blizzard Blanket. After 120 minutes, the pigs were moved to 21 degrees C to simulate a field hospital; group 1 was covered with Blankets. Blood was administered (groups 1 and 3, at 4 degrees C; group 2, via Thermal Angel) with 180 minutes of monitoring. The core temperature was <35 degrees C in five of five control pigs, four of five Blizzard-only pigs, and one of five Thermal Angel plus Blizzard Blanket pigs. The Blizzard Blanket limited but did not prevent hypothermia. The Thermal Angel plus Blizzard Blanket combination prevented hypothermia. The Thermal Angel is useful for bolus administration when electricity is limited; its military field use is constrained by battery weight and battery life.

  5. Myocardial protection in diffuse coronary artery disease. Intermittent retrograde cold-blood cardioplegia at systemic normothermia versus intermittent antegrade cold-blood cardioplegia at moderate systemic hypothermia.

    PubMed Central

    Hoffman, D; Fernandes, S; Frater, R W; Sisto, D

    1993-01-01

    In order to determine the comparative merits of antegrade cardioplegia at moderate systemic hypothermia versus retrograde cardioplegia at systemic normothermia, we performed coronary artery bypass grafting using intermittent oxygenated blood cardioplegia in 2 sets of 50 consecutive patients with triple-vessel disease (complete occlusion of 1 coronary artery and greater than 90% narrowing of the other 2, with poor distal runoff). Group 1 had antegrade cardioplegia at moderate systemic hypothermia (28 degrees C). Group 2 had retrograde cardioplegia at systemic normothermia. This resulted in no deaths and in no differences in complication rates. Group 2's postoperative need for inotropic agents or vasodilators was significantly less (epinephrine, p < 0.0009; dopamine, p < 0.002; nitroglycerin, p < 0.001). Elevations of CKMB fraction were significantly more common in Group 1: 46% had CKMB levels greater than 9%, versus 16% of Group 2 patients (p < 0.0001). Intraoperative transesophageal echocardiography was performed in 39 Group-1 patients and in 42 Group-2 patients. Development of a new wall-motion abnormality after bypass was significantly only in Group 1 (p < 0.009, by chi 2 analysis). We conclude that retrograde cardioplegia at normothermia provides myocardial protection that equals or surpasses that of antegrade delivery at moderate systemic hypothermia, while avoiding the possible deleterious side effects of hypothermia. PMID:8334370

  6. Association of serum lactate with outcome after out-of-hospital cardiac arrest treated with therapeutic hypothermia

    PubMed Central

    Novain, Michaël; Cattet, Florian; Plattier, Rémi; Nefzaoui, Mohamed; Hyvernat, Hervé; Raguin, Olivier; Kaidomar, Michel; Kerever, Sébastien; Ichai, Carole

    2017-01-01

    Aims Lactate reflects hypoxic insult in many conditions and is considered as a prognosis factor. But, after cardiac arrest, its interest is still debated. Our study aimed to assess the prognosis value of lactate in out-of-hospital cardiac arrest patients treated with therapeutic hypothermia. Methods This retrospective observational study included out-of-hospital cardiac arrest patients treated with therapeutic hypothermia in four ICUs. Lactate levels were compared at different times during the first 24 hours according to outcome at ICU discharge and to the type of death (multiorgan or neurologic failure). Results Two hundred and seventy-two patients were included, 89 good outcome and 183 poor outcome. In the latter group, 171 patients died, from multiorgan failure in 30% and neurologic failure in 70%. Lactate levels were higher in the poor compared to the good outcome patients at admission (5.4 (3.3–9.4) vs. 2.2 (1.5–3.6) mmol/L; p<0.01), 12 hours (2.5 (1.6–4.7) vs. 1.4 (1.0–2.2) mmol/L; p<0.01) and 24 hours (1.8 (1.1–2.8) vs. 1.3 (0.9–2.1) mmol/L; p<0.01). Patients succumbing from multiorgan failure exhibited higher lactate levels compared to those dying from neurologic failure at admission (7.9 (3.9–12.0) vs. 5.2 (3.3–8.8) mmol/L; p<0.01), H12 (4.9 (2.1–8.9) vs. 2.2 (1.4–3.4) mmol/L; p<0.01) and H24 (3.3 (1.8–5.5) vs. 1.4 (1.1–2.5) mmol/L; p<0.01). Initial lactate levels showed an increasing proportion of poor outcome from the first to fourth quartile. Conclusions After out-of-hospital cardiac arrest treated with therapeutic hypothermia, lactate levels during the first 24 hours seem linked with ICU outcome. Patients dying from multiorgan failure exhibit higher initial lactate concentrations than patients succumbing from neurological failure. PMID:28282398

  7. Retraction: Selective cerebro-myocardial perfusion under mild hypothermia during primary repair for aortic coarctation with ventricular septal defect.

    PubMed

    2013-04-01

    The following article from Artificial Organs, "Selective Cerebro-Myocardial Perfusion Under Mild Hypothermia During Primary Repair for Aortic Coarctation With Ventricular Septal Defect" by Huiwen Chen, Haifa Hong, Zhongqun Zhu and Jinfen Liu, published online on 2 November 2012 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor-in-Chief, Paul S. Malchesky, the International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc. The retraction has been agreed due to simultaneous publication of a substantially similar article, "Continuous Cerebral and Myocardial Perfusion During One-Stage Repair for Aortic Coarctation With Ventricular Septal Defect", by Huiwen Chen, Haifa Hong, Zhongqun Zhu and Jinfen Liu, in Pediatric Cardiology 7 November 2012 [Epub ahead of print].

  8. Fever Is Associated with Reduced, Hypothermia with Increased Mortality in Septic Patients: A Meta-Analysis of Clinical Trials

    PubMed Central

    Rumbus, Zoltan; Matics, Robert; Hegyi, Peter; Zsiboras, Csaba; Szabo, Imre; Illes, Anita; Petervari, Erika; Balasko, Marta; Marta, Katalin; Miko, Alexandra; Parniczky, Andrea; Tenk, Judit; Rostas, Ildiko; Solymar, Margit

    2017-01-01

    Background Sepsis is usually accompanied by changes of body temperature (Tb), but whether fever and hypothermia predict mortality equally or differently is not fully clarified. We aimed to find an association between Tb and mortality in septic patients with meta-analysis of clinical trials. Methods We searched the PubMed, EMBASE, and Cochrane Controlled Trials Registry databases (from inception to February 2016). Human studies reporting Tb and mortality of patients with sepsis were included in the analyses. Average Tb with SEM and mortality rate of septic patient groups were extracted by two authors independently. Results Forty-two studies reported Tb and mortality ratios in septic patients (n = 10,834). Pearson correlation analysis revealed weak negative linear correlation (R2 = 0.2794) between Tb and mortality. With forest plot analysis, we found a 22.2% (CI, 19.2–25.5) mortality rate in septic patients with fever (Tb > 38.0°C), which was higher, 31.2% (CI, 25.7–37.3), in normothermic patients, and it was the highest, 47.3% (CI, 38.9–55.7), in hypothermic patients (Tb < 36.0°C). Meta-regression analysis showed strong negative linear correlation between Tb and mortality rate (regression coefficient: -0.4318; P < 0.001). Mean Tb of the patients was higher in the lowest mortality quartile than in the highest: 38.1°C (CI, 37.9–38.4) vs 37.1°C (CI, 36.7–37.4). Conclusions Deep Tb shows negative correlation with the clinical outcome in sepsis. Fever predicts lower, while hypothermia higher mortality rates compared with normal Tb. Septic patients with the lowest (< 25%) chance of mortality have higher Tb than those with the highest chance (> 75%). PMID:28081244

  9. Adipose hypothermia in obesity and its association with period homolog 1, insulin sensitivity, and inflammation in fat.

    PubMed

    Yamaoka, Masaya; Maeda, Norikazu; Takayama, Yasunori; Sekimoto, Ryohei; Tsushima, Yu; Matsuda, Keisuke; Mori, Takuya; Inoue, Kana; Nishizawa, Hitoshi; Tominaga, Makoto; Funahashi, Tohru; Shimomura, Iichiro

    2014-01-01

    Visceral fat adiposity plays an important role in the development of metabolic syndrome. We reported previously the impact of human visceral fat adiposity on gene expression profile of peripheral blood cells. Genes related to circadian rhythm were highly associated with visceral fat area and period homolog 1 (PER1) showed the most significant negative correlation with visceral fat area. However, regulation of adipose Per1 remains poorly understood. The present study was designed to understand the regulation of Per1 in adipose tissues. Adipose Per1 mRNA levels of ob/ob mice were markedly low at 25 and 35 weeks of age. The levels of other core clock genes of white adipose tissues were also low in ob/ob mice at 25 and 35 weeks of age. Per1 mRNA was mainly expressed in the mature adipocyte fraction (MAF) and it was significantly low in MAF of ob/ob mice. To examine the possible mechanisms, 3T3-L1 adipocytes were treated with H2O2, tumor necrosis factor-α (TNF-α), S100A8, and lipopolysaccharide (LPS). However, no significant changes in Per1 mRNA level were observed by these agents. Exposure of cultured 3T3-L1 adipocytes to low temperature (33°C) decreased Per1 and catalase, and increased monocyte chemoattractant protein-1 (Mcp-1) mRNA levels. Hypothermia also worsened insulin-mediated Akt phosphorylation in 3T3-L1 adipocytes. Finally, telemetric analysis showed low temperature of adipose tissues in ob/ob mice. In obesity, adipose hypothermia seems to accelerate adipocyte dysfunction.

  10. Adipose Hypothermia in Obesity and Its Association with Period Homolog 1, Insulin Sensitivity, and Inflammation in Fat

    PubMed Central

    Yamaoka, Masaya; Maeda, Norikazu; Takayama, Yasunori; Sekimoto, Ryohei; Tsushima, Yu; Matsuda, Keisuke; Mori, Takuya; Inoue, Kana; Nishizawa, Hitoshi; Tominaga, Makoto; Funahashi, Tohru; Shimomura, Iichiro

    2014-01-01

    Visceral fat adiposity plays an important role in the development of metabolic syndrome. We reported previously the impact of human visceral fat adiposity on gene expression profile of peripheral blood cells. Genes related to circadian rhythm were highly associated with visceral fat area and period homolog 1 (PER1) showed the most significant negative correlation with visceral fat area. However, regulation of adipose Per1 remains poorly understood. The present study was designed to understand the regulation of Per1 in adipose tissues. Adipose Per1 mRNA levels of ob/ob mice were markedly low at 25 and 35 weeks of age. The levels of other core clock genes of white adipose tissues were also low in ob/ob mice at 25 and 35 weeks of age. Per1 mRNA was mainly expressed in the mature adipocyte fraction (MAF) and it was significantly low in MAF of ob/ob mice. To examine the possible mechanisms, 3T3-L1 adipocytes were treated with H2O2, tumor necrosis factor-α (TNF-α), S100A8, and lipopolysaccharide (LPS). However, no significant changes in Per1 mRNA level were observed by these agents. Exposure of cultured 3T3-L1 adipocytes to low temperature (33°C) decreased Per1 and catalase, and increased monocyte chemoattractant protein-1 (Mcp-1) mRNA levels. Hypothermia also worsened insulin-mediated Akt phosphorylation in 3T3-L1 adipocytes. Finally, telemetric analysis showed low temperature of adipose tissues in ob/ob mice. In obesity, adipose hypothermia seems to accelerate adipocyte dysfunction. PMID:25397888

  11. Effects of acidosis, alkalosis, hyperthermia and hypothermia on haemostasis: results of point-of-care testing with the thromboelastography analyser.

    PubMed

    Ramaker, Albert J D W R; Meyer, Peter; van der Meer, Jan; Struys, Michel M R F; Lisman, Ton; van Oeveren, Wim; Hendriks, Herman G D

    2009-09-01

    In this study we assessed the effects of changes in pH, temperature, and their combination in whole blood on thromboelastographic variables. Blood was collected from six healthy volunteers. Thromboelastograph (TEG series 5000; Haemoscope Corporation, Illinois, USA) channels were set at temperatures of 32, 37, and 39 degrees C and each was filled with artificially acidified, alkalified, and neutral blood, respectively. Acidification (pH 6.95) significantly impairs thromboelastographic variables reaction time r (from 23.3 to 33.7 min; P = 0.0280), kinetic time k (from 8.7 to 16.1 min; P = 0.028), angle alpha (from 24.3 degrees to 13.8 degrees ; P = 0.028), prothrombin time (from 11.4 to 12.1 s; P = 0.044), and activated partial thromboplastin time (from 29.3 to 45.0 s; P = 0.028). A temperature drop from 37 to 32 degrees C in blood of neutral pH significantly impaired k (from 8.7 to 10.2 min; P = 0.028) and alpha (from 24.3 degrees to 21.0 degrees ; P = 0.027), whereas maximum amplitude ma significantly increased (from 46.5 to 52.5 mm; P = 0.027). A temperature rise from 37 to 39 degrees C at pH 7.37 did not affect any of the TEG variables. Artificial alkalization (pH 7.68) at a temperature of 37 degrees C had no effect on any of the measured variables. Acidosis causes a significant impairment of clot formation and clot strength. Hypothermia had the same effects, but to a lesser extent. These findings emphasize the need for correction of acidosis and hypothermia to normalize haemostasis.

  12. Mild hypothermia during global cardiac ischemia opens a window of opportunity to develop heart donation after cardiac death.

    PubMed

    Stadelmann, Mathieu; Dornbierer, Monika; Clément, David; Gahl, Brigitta; Dick, Florian; Carrel, Thierry P; Tevaearai, Hendrik T; Longnus, Sarah

    2013-03-01

    Although heart donation after cardiac death (DCD) could greatly improve graft availability, concerns regarding warm ischemic damage typically preclude transplantation. Improving tolerance to warm ischemia may thus open a window of opportunity for DCD hearts. We investigated the hypothesis that, compared with normothermia, mild hypothermia (32° C) initiated after ischemic onset improves cardiac functional recovery upon reperfusion. Isolated, working hearts from adult, male Wistar rats underwent global, no-flow ischemia, and reperfusion (n = 28). After ischemic onset, temperature was maintained at either 37° C for 20 or 30 min or reduced to 32° C for 40, 50, or 60 min. Recovery was measured after 60-min reperfusion. Following normothermic ischemia, recovery of rate-pressure product (RPP; per cent of preischemic value) was almost complete after 20-min ischemia (97 ± 9%), whereas no recovery was detectable after 30-min ischemia. After mildly hypothermic ischemia (32° C), RPP also recovered well after 40 min (86 ± 4%). Markers of metabolism and necrosis were similar in 37° C/20 min and 32° C/40 min groups. Simple reduction in cardiac temperature by a few degrees after the onset of global ischemia dramatically prolongs the interval during which the heart remains resistant to functional deterioration. Preservation of hemodynamic function is associated with improved metabolic recovery and reduced necrosis. The application of mild hypothermia may be a simple first step towards development of clinical protocols for DCD heart recovery.

  13. The effects of hypothermia on myocardial oxygen consumption and transmural coronary blood flow in the potassium-arrested heart.

    PubMed Central

    Chitwood, W R; Sink, J D; Hill, R C; Wechsler, A S; Sabiston, D C

    1979-01-01

    Hypothermia remains the primary adjunct employed to lower cellular metabolism during various cardiac procedures. In these experiments, left ventricular myocardial oxygen consumption (MVO2) and transmural blood flow (TBF) were measured during cardiopulmonary bypass with the range of temperatures used clinically. Determinations were made in empty beating normothermic hearts and after potassium cardioplegia at 37, 32, 28, 22, 18, and 15 degrees (K+ = 15--37 meq/L: Hct 25 volumes %). Oxygen content of the total coronary sinus collection was compared with a large volume arterial sample using a Lex-O2-Con-TL analyzer (vs Van Slyke, R = 0.98). Transmural blood flow was measured at each temperature using microspheres (8 microns), and perfusion was maintained at 80 mmHg. Asystole (37 degrees) alone decreased MVO2 from 5.18 +/- 0.55 to 1.85 +/- 0.20 ml O2/min/100 g of left ventricle or approximately 65% (p less than 0.001). With progressive cooling to 15 degrees an additional 82% decrement in oxygen uptake occurred during asystole (p less than 0.001). During asystole at 37 degrees the decrease in MVO2 was reflected mainly by a large decrement (p less than 0.01) in TBF (1.27 +/- 0.19 to 0.74 +/- 0.17 ml/min/g of mean left ventricular flow). However, with cooling below 32 degrees, the arteriovenous oxygen difference narrowed progressively (p less than 0.001) while TBF paradoxically returned to control levels. Endocardial/epicardial flow ratios were not altered by cooling. These data not only confirm earlier reports describing a sequential drop in MVO2 with incremental myocardial cooling, but also establish MVO2 levels for perfused hearts arrested by potassium at lower temperatures (18--15 degrees). Moreover, as transmural blood flow becomes independent of metabolic necessity during hypothermia, coronary autoregulation appears to be impaired, possibly affecting detrimental tissue over perfusion. PMID:464672

  14. Transarterial regional hypothermia provides robust neuroprotection in a rat model of permanent middle cerebral artery occlusion with transient collateral hypoperfusion.

    PubMed

    Kurisu, Kota; Abumiya, Takeo; Ito, Masaki; Gekka, Masayuki; Osanai, Toshiya; Shichinohe, Hideo; Nakayama, Naoki; Kazumata, Ken; Houkin, Kiyohiro

    2016-11-15

    The robust neuroprotective effects of transarterial regional hypothermia have been demonstrated in the typical transient middle cerebral artery occlusion (tMCAO) model, but have not yet been tested in other ischemic stroke models, even though clinical ischemic conditions are diverse. In order to clarify these effects in a different ischemic stroke model, we employed a rat model of permanent MCAO (pMCAO) with transient collateral hypoperfusion (tCHP), which was achieved by direct MCA ligation through craniotomy and 1-h bilateral common carotid artery occlusion at the beginning of pMCAO. The infusion of 20ml/kg of 4°C cold saline (CS) or 37°C warm saline (WS) into the ipsilateral internal carotid artery (ICA) was performed for 15min in intra- or post-tCHP. Neurological scores, infarct/edema volumes, and neuronal apoptosis and reactive gliosis were compared between the CS and WS groups and a non-infusion control group after 48h of reperfusion. Although brain temperatures were only reduced by 2-3°C for 15min, the CS group had significantly better neurological scores, smaller infarct/edema volumes, and less penumbral neuronal apoptosis and reactive gliosis than the control and WS groups. The post-tCHP CS group exhibited prominent neuroprotective effects, even though infarct volumes and neuronal apoptosis were reduced less than those in the intra-tCHP CS group. In conclusion, we demonstrated the neuroprotective effects of transarterial regional hypothermia in an ischemic model of pMCAO with tCHP. Even though MCAO is persistent, cold infusion via the ICA is neuroprotective for the penumbra, suggesting the wider therapeutic application of this therapy.

  15. Urinary gas chromatography mass spectrometry metabolomics in asphyxiated newborns undergoing hypothermia: from the birth to the first month of life

    PubMed Central

    Noto, Antonio; Pomero, Giulia; Barberini, Luigi; Fattuoni, Claudia; Palmas, Francesco; Dalmazzo, Cristina; Delogu, Antonio; Dessì, Angelica; Fanos, Vassilios; Gancia, Paolo

    2016-01-01

    Background Perinatal asphyxia is a severe clinical condition affecting around four million newborns worldwide. It consists of an impaired gas exchange leading to three biochemical components: hypoxemia, hypercapnia and metabolic acidosis. Methods The aim of this longitudinal experimental study was to identify the urine metabolome of newborns with perinatal asphyxia and to follow changes in urine metabolic profile over time. Twelve babies with perinatal asphyxia were included in this study; three babies died on the eighth day of life. Total-body cooling for 72 hours was carried out in all the newborns. Urine samples were collected in each baby at birth, after 48 hours during hypothermia, after the end of the therapeutic treatment (72 hours), after 1 week of life, and finally after 1 month of life. Urine metabolome at birth was considered the reference against which to compare metabolic profiles in subsequent samples. Quantitative metabolic profiling in urine samples was measured by gas chromatography mass spectrometry (GC-MS). The statistical approach was conducted by using the multivariate analysis by means of principal component analysis (PCA) and orthogonal partial least square discriminant analysis (OPLS-DA). Pathway analysis was also performed. Results The most important metabolites depicting each time collection point were identified and compared each other. At birth before starting therapeutic hypothermia (TH), urine metabolic profiles of the three babies died after 7 days of life were closely comparable each other and significantly different from those in survivors. Conclusions In conclusion, a plethora of data have been extracted by comparing the urine metabolome at birth with those observed at each time point collection. The modifications over time in metabolites composition and concentration, mainly originated from the depletion of cellular energy and homeostasis, seems to constitute a fingerprint of perinatal asphyxia. PMID:27942508

  16. Effects of xenon and hypothermia on cerebrovascular pressure reactivity in newborn global hypoxic-ischemic pig model.

    PubMed

    Chakkarapani, Elavazhagan; Dingley, John; Aquilina, Kristian; Osredkar, Damjan; Liu, Xun; Thoresen, Marianne

    2013-11-01

    Autoregulation of cerebral perfusion is impaired in hypoxic-ischemic encephalopathy. We investigated whether cerebrovascular pressure reactivity (PRx), an element of cerebral autoregulation that is calculated as a moving correlation coefficient between averages of intracranial and mean arterial blood pressure (MABP) with values between -1 and +1, is impaired during and after a hypoxic-ischemic insult (HI) in newborn pigs. Associations between end-tidal CO2, seizures, neuropathology, and PRx were investigated. The effect of hypothermia (HT) and Xenon (Xe) on PRx was studied. Pigs were randomized to Sham, and after HI to normothermia (NT), HT, Xe or xenon hypothermia (XeHT). We defined PRx >0.2 as peak and negative PRx as preserved. Neuropathology scores after 72 hours of survival was grouped as 'severe' or 'mild.' Secondary PRx peak during recovery, predictive of severe neuropathology and associated with insult severity (P=0.05), was delayed in HT (11.5 hours) than in NT (6.5 hours) groups. Seizures were associated with impaired PRx in NT pigs (P=0.0002), but not in the HT/XeHT pigs. PRx was preserved during normocapnia and impaired during hypocapnia. Xenon abolished the secondary PRx peak, increased (mean (95% confidence interval (CI)) MABP (6.5 (3.8, 9.4) mm Hg) and cerebral perfusion pressure (5.9 (2.9, 8.9) mm Hg) and preserved the PRx (regression coefficient, -0.098 (95% CI (-0.18, -0.01)), independent of the insult severity.

  17. Effects of morphine on pentobarbital-induced responses in mu-opioid receptor knockout mice.

    PubMed

    Park, Y; Ho, I K; Jang, C G; Tanaka, S; Ma, T; Loh, H H; Ko, K H

    2001-03-15

    Effects of morphine on the potentiation of pentobarbital-induced responses were investigated using mu-opioid receptor knockout mice. The duration of loss of righting reflex, hypothermia, and loss of motor coordination induced by pentobarbital were measured after pretreatment with either morphine or saline. Morphine pretreatment failed to show potentiation of both pentobarbital-induced loss of righting reflex and hypothermia in mu-opioid receptor knockout mice, while it significantly potentiated these responses in the wild-type controls. For motor incoordination test, morphine potentiated pentobarbital-induced motor incoordination in the wild-type mice. However, morphine may have opposite effects in the mu-opioid receptor knockout mice. These results demonstrate that synergism between morphine and pentobarbital is not detected in mu-opioid receptor knockout mice and that potentiation of pentobarbital-induced loss of righting reflex and hypothermia by morphine is mediated through mu-opioid receptor. It was interesting to note that pentobarbital-induced decrease in body temperature was less severe in mu-opioid receptor knockout mice than in wild-type mice.

  18. [Cellular composition of diffuse lymphoid tissue in the mucous membrane of human larynx under conditions of physiological norm and in fatal hypothermia in the Republic of Sakha (Yakutia)].

    PubMed

    Buzinaeva, M T; Garmayeva, D K

    2013-01-01

    Using histological, morphometric and immunnohistochemical methods, cellular composition and cytoarchitectonics of diffuse lymphoid tissue in the mucous membrane of the larynx was studied in 29 men aged 17-74 years, who died from general body hypothermia in the winter period and in 27 men who died from mechanical injury during the summer. Significant changes in the cellular composition of diffuse lymphoid tissue of the mucous membrane in the various parts of the larynx were detected in fatal hypothermia, which included the decrease in the number of T-, B-lymphocytes and plasma cells and the increase in the number of macrophages in all age groups, indicating the suppression of local immunity in persons who died due to the action of low temperature.

  19. Study protocol - A systematic review and meta-analysis of hypothermia in experimental traumatic brain injury: Why have promising animal studies not been replicated in pragmatic clinical trials?

    PubMed

    Hirst, Theodore C; Watzlawick, Ralf; Rhodes, Jonathan K; Macleod, Malcolm R; Andrews, Peter J D

    2016-12-01

    Traumatic brain injury (TBI) is a major cause of death and permanent disability. Systemic hypothermia, a treatment used in TBI for many decades, has recently been found to be associated with neutral or unfavourable clinical outcomes despite apparently promising preclinical research. Systematic review and meta-analysis is a tool to summarize literature and observe trends in experimental design and quality that underpin its general conclusions. Here we aim to use these techniques to describe the use of hypothermia in animal TBI models, collating data relating to outcome and both study design and quality. From here we intend to observe correlations between features and attempt to explain any discrepancies found between animal and clinical data. This protocol describes the relevant methodology in detail.

  20. Investigation of oxyhemoglobin and carboxyhemoglobin ratios in right and left cardiac blood for diagnosis of fatal hypothermia and death by fire.

    PubMed

    Kanto-Nishimaki, Yuko; Saito, Haruka; Watanabe-Aoyagi, Miwako; Toda, Ritsuko; Iwadate, Kimiharu

    2014-11-01

    Few large-scale investigations have looked at the oxyhemoglobin ratio (%O2-Hb) or the carboxyhemoglobin ratio (%CO-Hb) in fatal hypothermia and death by fire as applicable to forensic medicine. We therefore retrospectively examined right and left cardiac blood samples for both %O2-Hb and %CO-Hb in 690 forensic autopsy cases. We therefore sought to establish reference values for the above forensic diagnoses, to compare %O2-Hb in fatal hypothermia with or without cardiopulmonary resuscitation (CPR), and to compare the relationship between %CO-Hb and smoking history. All %O2-Hb and %CO-Hb data were obtained during or immediately after autopsies using a portable CO-oximeter. Death by carbon monoxide (CO) intoxication and death by fire were excluded from the analysis involving smoking history. In fatal hypothermia, %O2-Hb in the left cardiac blood was significantly higher than that in the right cardiac blood, providing important evidence for fatal hypothermia. Furthermore, %O2-Hb in the left cardiac blood increases with CPR but that in the right cardiac blood increases in parallel. No correlation was observed between rectal temperature and %O2-Hb in the right and left cardiac blood, indicating that it is unlikely that postmortem cooling increases %O2-Hb in cardiac blood. %CO-Hb in smokers was significantly higher than that in non-smokers, although the number of cigarettes smoked did not appear to be significant. When assessing death by fire, we identified that %CO-Hb of >10% was a reliable marker of antemortem CO inhalation, regardless of smoking history.

  1. Hypothermia. An Educational Manual for Instruction of the Fleet Duty Corpsman Accompanying Personnel Performing Operations in Cold Water or Cold Weather

    DTIC Science & Technology

    1980-11-01

    been cases of epilepsy and dysphagia reported after recovery from severe hypothermia. These are extremely rare and thought to be due to some greater...the rule and a guideline is that one is adequately rewarmed when sweating begins. Good diet and fluid intake should be adhered to. Alcohol...Loncle $ C. Boutelier; Mathematical Model ofa Man1& Tolerance to Cold Using Mohphological T-acoths, Aviat. Space Environ. Med. 47:958-964, Sept

  2. Reversible Hypothermia-Induced Inhibition of Human Platelet Activation in Whole Blood in Vitro and in Vivo

    DTIC Science & Technology

    2007-11-02

    IX complex (the von Willebrand factor receptor) (12), thromboxane Bj generation (the stable metabolite of thromboxane A2) (13), platelet aggregate...6D1 (provided by Dr. Barry S. Coller, SUNY, Stony Brook) is directed against the von Willebrand factor receptor on the glycocalicin portion of the a...Fig 1, panel A) and, after a delay of approximately 20 seconds, downregulation of the platelet surface expression of GPIb (the von Willebrand factor

  3. Therapeutic Hypothermia for Refractory Status Epilepticus in a Child with Malignant Migrating Partial Seizures of Infancy and SCN1A Mutation: A Case Report

    PubMed Central

    Shein, Steven L.; Reynolds, Thomas Q.; Gedela, Satyanarayana; Kochanek, Patrick M.

    2012-01-01

    Status epilepticus (SE) is a common indication for neurocritical care and can be refractory to standard measures. Refractory SE (RSE) is associated with high morbidity and mortality. Unconventional therapies may be utilized in certain cases, including therapeutic hypothermia (TH), bumetanide, and the ketogenic diet. However, the literature describing the use of such therapies in RSE is limited. Details of a case of TH for RSE in an infant with malignant migrating partial seizures of infancy were obtained from the medical record. A 4-month-old child developed SE that was refractory to treatment with concurrent midazolam, phenobarbital, fosphenytoin, topiramate, levetiracetam, folinic acid, and pyridoxal-5-phosphate. This led to progressive implementation of three unconventional therapies: TH, bumetanide, and the ketogentic diet. Electrographic seizures ceased for the entirety of a 43-hour period of TH with a target rectal temperature of 33.0°C–34.0°C. No adverse effects of hypothermia were noted other than a single episode of asymptomatic hypokalemia. Seizures recurred 10 hours after rewarming was begun and did not abate with reinstitution of hypothermia. No effect was seen with administration of bumetanide. Seizures were controlled long-term within 48 hours of institution of the ketogenic diet. TH and the ketogenic diet may be effective for treating RSE in children. PMID:23667778

  4. Effect of radiant heat at the birth site in farrowing crates on hypothermia and behaviour in neonatal piglets.

    PubMed

    Andersen, H M-L; Pedersen, L J

    2016-01-01

    It has been documented that floor heating of the farrowing area in loose housed sows improves survival of piglets significantly. However, today, the majority of farrowing pens are designed with crating of sows and slatted floor at the birth site. The aim of this study was to investigate whether providing radiant heat at the birth site to new-born piglets in pens with crated sows reduced hypothermia, time to first milk intake and growth of the piglets during the 1(st) week. Second parity Danish Landrace×Yorkshire sows (n=36) were randomly divided into two groups: Control (CG) and heat (HG). In the area behind the sow (zone 1), two radiant heat panels were mounted above the slatted floor in the HG. The farrowings were attended, and the heaters were turned on at birth of first piglet and turned off 12 h after. Birth time, time to leave zone 1, time to first contact with udder and time to first suckling were registered by direct observation. The piglet's rectal temperature (RT) was measured 15, 30, 60, 120, 180, 240 min after birth and 12, 14 and 24 h after birth of first piglet. Piglets were weighed at birth, 24 and 48 h and 7 days after birth. Data were analysed in a mixed model in SAS. The drop in RT was lower in HG compared with CG (P=0.002), and the RT in HG remained higher than in CG from 30 to 240 min after birth (P<0.05), whereas no difference was found at 12 h after birth of first piglet (P=0.92). Piglets in HG stayed longer in zone 1 than those in CG (P=0.01), whereas time to reach udder (P=0.35) and to first suckling (P=0.56) did not differ. No difference in weight gain was found between piglets in HG and CG at 24 h (P=0.23), 48 h (P=0.28) and 7 days after birth (P=0.44). Birth weight had a positive effect on RT (P<0.001) and reduced time to leave zone 1 (P<0.01), reach udder (P<0.001) and time to first suckling (P<0.001). The results showed that radiant heating behind the sows reduced hypothermia in new-born piglets and indicate that providing heat during

  5. Setting Up an Efficient Therapeutic Hypothermia Team in Conscious ST Elevation Myocardial Infarction Patients: A UK Heart Attack Center Experience.

    PubMed

    Islam, Shahed; Hampton-Till, James; MohdNazri, Shah; Watson, Noel; Gudde, Ellie; Gudde, Tom; Kelly, Paul A; Tang, Kare H; Davies, John R; Keeble, Thomas R

    2015-12-01

    Patients presenting with ST elevation myocardial infarction (STEMI) are routinely treated with percutaneous coronary intervention to restore blood flow in the occluded artery to reduce infarct size (IS). However, there is evidence to suggest that the restoration of blood flow can cause further damage to the myocardium through reperfusion injury (RI). Recent research in this area has focused on minimizing damage to the myocardium caused by RI. Therapeutic hypothermia (TH) has been shown to be beneficial in animal models of coronary artery occlusion in reducing IS caused by RI if instituted early in an ischemic myocardium. Data in humans are less convincing to date, although exploratory analyses suggest that there is significant clinical benefit in reducing IS if TH can be administered at the earliest recognition of ischemia in anterior myocardial infarction. The Essex Cardiothoracic Centre is the first UK center to have participated in administering TH in conscious patients presenting with STEMI as part of the COOL-AMI case series study. In this article, we outline our experience of efficiently integrating conscious TH into our primary percutaneous intervention program to achieve 18 minutes of cooling duration before reperfusion, with no significant increase in door-to-balloon times, in the setting of the clinical trial.

  6. Brain tissue partial pressure of oxygen predicts the outcome of severe traumatic brain injury under mild hypothermia treatment

    PubMed Central

    Sun, Hongtao; Zheng, Maohua; Wang, Yanmin; Diao, Yunfeng; Zhao, Wanyong; Wei, Zhengjun

    2016-01-01

    Objective The aim of this study was to investigate the clinical significance and changes of brain tissue partial pressure of oxygen (PbtO2) in the course of mild hypothermia treatment (MHT) for treating severe traumatic brain injury (sTBI). Methods There were 68 cases with sTBI undergoing MHT. PbtO2, intracranial pressure (ICP), jugular venous oxygen saturation (SjvO2), and cerebral perfusion pressure (CPP) were continuously monitored, and clinical outcomes were evaluated using the Glasgow Outcome Scale score. Results Of 68 patients with sTBI, PbtO2, SjvO2, and CPP were obviously increased, but decreased ICP level was observed throughout the MHT. PbtO2 and ICP were negatively linearly correlated, while there was a positive linear correlation between PbtO2 and SjvO2. Monitoring CPP and SjvO2 was performed under normal circumstances, and a large proportion of patients were detected with low PbtO2. Decreased PbtO2 was also found after MHT. Conclusion Continuous PbtO2 monitoring could be introduced to evaluate the condition of regional cerebral oxygen metabolism, thereby guiding the clinical treatment and predicting the outcome. PMID:27601907

  7. Galectin-3 expression in hippocampal CA2 following transient forebrain ischemia and its inhibition by hypothermia or antiapoptotic agents.

    PubMed

    Hisamatsu, Kenji; Niwa, Masayuki; Kobayashi, Kazuhiro; Miyazaki, Tatsuhiko; Hirata, Akihiro; Hatano, Yuichiro; Tomita, Hiroyuki; Hara, Akira

    2016-03-23

    Recent evidence has suggested that the hippocampal CA2 region plays an important role in the recognition process. We have reported that ischemic damage in the hippocampal CA2 region following transient ischemia is caused by apoptosis, but the underlying mechanisms are still not clear. Galectin-3 is a β-galactosidase-binding lectin that is important in cell proliferation and apoptotic regulation. We have also reported that galectin-3 was expressed in activated microglia in the CA1 region 96 h after transient ischemia. The aim of this study is to determine the localization and time course of galectin-3 expression in the CA2 region following transient forebrain ischemia. Galectin-3 immunostaining was observed in both interior side of CA1 region and CA2 region in hippocampus 60 h after ischemic insult. At 66 h, galectin-3 was observed in the whole CA1 region adjacent to the CA2 region in the hippocampus. Both galectin-3 expression and neuronal cell death in the CA2 region were significantly inhibited by hypothermia and by apoptosis-inhibiting reagents. These results suggest that galectin-3 in the CA2 region is expressed independent of that in the CA1 region. Protection of the expression of galectin-3 in the CA2 region might contribute toward the survival of CA2 pyramidal neurons.

  8. Galectin-3 expression in hippocampal CA2 following transient forebrain ischemia and its inhibition by hypothermia or antiapoptotic agents

    PubMed Central

    Hisamatsu, Kenji; Kobayashi, Kazuhiro; Miyazaki, Tatsuhiko; Hirata, Akihiro; Hatano, Yuichiro; Tomita, Hiroyuki; Hara, Akira

    2016-01-01

    Recent evidence has suggested that the hippocampal CA2 region plays an important role in the recognition process. We have reported that ischemic damage in the hippocampal CA2 region following transient ischemia is caused by apoptosis, but the underlying mechanisms are still not clear. Galectin-3 is a β-galactosidase-binding lectin that is important in cell proliferation and apoptotic regulation. We have also reported that galectin-3 was expressed in activated microglia in the CA1 region 96 h after transient ischemia. The aim of this study is to determine the localization and time course of galectin-3 expression in the CA2 region following transient forebrain ischemia. Galectin-3 immunostaining was observed in both interior side of CA1 region and CA2 region in hippocampus 60 h after ischemic insult. At 66 h, galectin-3 was observed in the whole CA1 region adjacent to the CA2 region in the hippocampus. Both galectin-3 expression and neuronal cell death in the CA2 region were significantly inhibited by hypothermia and by apoptosis-inhibiting reagents. These results suggest that galectin-3 in the CA2 region is expressed independent of that in the CA1 region. Protection of the expression of galectin-3 in the CA2 region might contribute toward the survival of CA2 pyramidal neurons. PMID:26848998

  9. Setting Up an Efficient Therapeutic Hypothermia Team in Conscious ST Elevation Myocardial Infarction Patients: A UK Heart Attack Center Experience

    PubMed Central

    Islam, Shahed; Hampton-Till, James; MohdNazri, Shah; Watson, Noel; Gudde, Ellie; Gudde, Tom; Kelly, Paul A.; Tang, Kare H.

    2015-01-01

    Patients presenting with ST elevation myocardial infarction (STEMI) are routinely treated with percutaneous coronary intervention to restore blood flow in the occluded artery to reduce infarct size (IS). However, there is evidence to suggest that the restoration of blood flow can cause further damage to the myocardium through reperfusion injury (RI). Recent research in this area has focused on minimizing damage to the myocardium caused by RI. Therapeutic hypothermia (TH) has been shown to be beneficial in animal models of coronary artery occlusion in reducing IS caused by RI if instituted early in an ischemic myocardium. Data in humans are less convincing to date, although exploratory analyses suggest that there is significant clinical benefit in reducing IS if TH can be administered at the earliest recognition of ischemia in anterior myocardial infarction. The Essex Cardiothoracic Centre is the first UK center to have participated in administering TH in conscious patients presenting with STEMI as part of the COOL-AMI case series study. In this article, we outline our experience of efficiently integrating conscious TH into our primary percutaneous intervention program to achieve 18 minutes of cooling duration before reperfusion, with no significant increase in door-to-balloon times, in the setting of the clinical trial. PMID:26154447

  10. Body temperature effect on methylenedioxymethamphetamine-induced acute decrease in tryptophan hydroxylase activity.

    PubMed

    Che, S; Johnson, M; Hanson, G R; Gibb, J W

    1995-12-07

    Brain tryptophan hydroxylase activity decreases within 15 min after a single administration of 3,4-methylenedioxymethamphetamine. In the present study, the effect of body temperature on this acute decrease of tryptophan hydroxylase activity was examined. 2 h after a single dose of 3,4-methylenedioxymethamphetamine (20 mg/kg, s.c.), rats exhibited hyperthermia (38.7 degrees C) or hypothermia (35.8 degrees C) when maintained at 25 degrees C or 6 degrees C, respectively. The rectal temperature of control animals maintained at 6 degrees C was not altered. Tryptophan hydroxylase activity measured in the hippocampus, striatum and frontal cortex of hyperthermic rats treated with 3,4-methylenedioxymethamphetamine was decreased to 61%, 65%, and 71% of control levels, respectively, 2 h after drug treatment. However, in hypothermic rats, 3,4-methylenedioxymethamphetamine had no effect on tryptophan hydroxylase activity in the hippocampus, striatum or frontal cortex. Non-drug-induced hyperthermia or hypothermia did not affect tryptophan hydroxylase activity. Since hypothermia may prevent the 3,4-methylenedioxymethamphetamine-induced decrease in tryptophan hydroxylase activity by reducing the formation of free radicals, the effect of a free radical scavenging agent, N-tert-butyl-alpha-phenylnitrone, was examined. N-tert-butyl-alpha-phenylnitrone (200 mg/kg, i.p.) alone caused hypothermia but had no direct effect on tryptophan hydroxylase activity. Preadministration of N-tert-butyl-alpha-phenylnitrone prevented 3,4-methylenedioxymethamphetamine from raising the temperature above normal and attenuated the drug-induced decrease in tryptophan hydroxylase activity in hippocampus, striatum and frontal cortex. However, when the rats treated with a combination of N-tert-butyl-alpha-phenylnitrone and 3,4-methylenedioxymethamphetamine were maintained at hyperthermic conditions, N-tert-butyl-alpha-phenylnitrone had no protective effect. These results suggest that body temperature plays a

  11. Levodopa in Treatment of Decompression Sickness and of Air Embolism Induced Paraplegia in Rats.

    DTIC Science & Technology

    1981-08-28

    of cardiogenic shock . Levodopa induces mesenteric, renal and cerebral vasodilation. In this work we studied the effect of hypothermia on pressor...anesthesia (Bevan et al., 1973; Popovic at al., 1977). Beneficial effects of levodopa and dopamine have been demonstrated in cardiogenic (Goldberg et al., 1977...Stephens et al., 1978) and noncardiogenic shock (Samii et al., 1978). The major benefit obtained with dopamine treatment seems to be an im

  12. Moderate hypothermia within 6 h of birth plus inhaled xenon versus moderate hypothermia alone after birth asphyxia (TOBY-Xe): a proof-of-concept, open-label, randomised controlled trial

    PubMed Central

    Azzopardi, Denis; Robertson, Nicola J; Bainbridge, Alan; Cady, Ernest; Charles-Edwards, Geoffrey; Deierl, Aniko; Fagiolo, Gianlorenzo; Franks, Nicholas P; Griffiths, James; Hajnal, Joseph; Juszczak, Edmund; Kapetanakis, Basil; Linsell, Louise; Maze, Mervyn; Omar, Omar; Strohm, Brenda; Tusor, Nora; Edwards, A David

    2016-01-01

    Summary Background Moderate cooling after birth asphyxia is associated with substantial reductions in death and disability, but additional therapies might provide further benefit. We assessed whether the addition of xenon gas, a promising novel therapy, after the initiation of hypothermia for birth asphyxia would result in further improvement. Methods Total Body hypothermia plus Xenon (TOBY-Xe) was a proof-of-concept, randomised, open-label, parallel-group trial done at four intensive-care neonatal units in the UK. Eligible infants were 36–43 weeks of gestational age, had signs of moderate to severe encephalopathy and moderately or severely abnormal background activity for at least 30 min or seizures as shown by amplitude-integrated EEG (aEEG), and had one of the following: Apgar score of 5 or less 10 min after birth, continued need for resuscitation 10 min after birth, or acidosis within 1 h of birth. Participants were allocated in a 1:1 ratio by use of a secure web-based computer-generated randomisation sequence within 12 h of birth to cooling to a rectal temperature of 33·5°C for 72 h (standard treatment) or to cooling in combination with 30% inhaled xenon for 24 h started immediately after randomisation. The primary outcomes were reduction in lactate to N-acetyl aspartate ratio in the thalamus and in preserved fractional anisotropy in the posterior limb of the internal capsule, measured with magnetic resonance spectroscopy and MRI, respectively, within 15 days of birth. The investigator assessing these outcomes was masked to allocation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00934700, and with ISRCTN, as ISRCTN08886155. Findings The study was done from Jan 31, 2012, to Sept 30, 2014. We enrolled 92 infants, 46 of whom were randomly assigned to cooling only and 46 to xenon plus cooling. 37 infants in the cooling only group and 41 in the cooling plus xenon group underwent magnetic resonance assessments

  13. Early-Stage Hyperoxia Is Associated with Favorable Neurological Outcomes and Survival after Severe Traumatic Brain Injury: A Post-Hoc Analysis of the Brain Hypothermia Study.

    PubMed

    Fujita, Motoki; Oda, Yasutaka; Yamashita, Susumu; Kaneda, Kotaro; Kaneko, Tadashi; Suehiro, Eiichi; Dohi, Kenji; Kuroda, Yasuhiro; Kobata, Hitoshi; Tsuruta, Ryosuke; Maekawa, Tsuyoshi

    2017-01-19

    The effects of hyperoxia on the neurological outcomes of patients with severe traumatic brain injury (TBI) are still controversial. We examined whether the partial pressure of arterial oxygen (PaO2) and hyperoxia were associated with neurological outcomes and survival by conducting post-hoc analyses of the Brain Hypothermia (B-HYPO) study, a multi-center randomized controlled trial of mild therapeutic hypothermia for severe TBI. The differences in PaO2 and PaO2/fraction of inspiratory oxygen (P/F) ratio on the 1st day of admission were compared between patients with favorable (n = 64) and unfavorable (n = 65) neurological outcomes and between survivors (n = 90) and deceased patients (n = 39). PaO2 and the P/F ratio were significantly greater in patients with favorable outcomes than in patients with unfavorable neurological outcomes (PaO2: 252 ± 122 vs. 202 ± 87 mm Hg, respectively, p = 0.008; P/F ratio: 455 ± 171 vs. 389 ± 155, respectively, p = 0.022) and in survivors than in deceased patients (PaO2: 242 ± 117 vs. 193 ± 75 mm Hg, respectively, p = 0.005; P/F ratio: 445 ± 171 vs. 370 ± 141, respectively, p = 0.018). Similar tendencies were observed in subgroup analyses in patients with fever control and therapeutic hypothermia, and in patients with an evacuated mass or other lesions (unevacuated lesions). PaO2 was independently associated with survival (odds ratio 1.008, p = 0.037). These results suggested that early-stage hyperoxia might be associated with favorable neurological outcomes and survival following severe TBI.

  14. Therapeutic Hypothermia Reduces Intracranial Pressure and Partial Brain Oxygen Tension in Patients with Severe Traumatic Brain Injury: Preliminary Data from the Eurotherm3235 Trial

    PubMed Central

    Rhodes, Jonathan; Andrews, Peter J.D.

    2015-01-01

    Traumatic brain injury (TBI) is a significant cause of disability and death and a huge economic burden throughout the world. Much of the morbidity associated with TBI is attributed to secondary brain injuries resulting in hypoxia and ischemia after the initial trauma. Intracranial hypertension and decreased partial brain oxygen tension (PbtO2) are targeted as potentially avoidable causes of morbidity. Therapeutic hypothermia (TH) may be an effective intervention to reduce intracranial pressure (ICP), but could also affect cerebral blood flow (CBF). This is a retrospective analysis of prospectively collected data from 17 patients admitted to the Western General Hospital, Edinburgh. Patients with an ICP >20 mmHg refractory to initial therapy were randomized to standard care or standard care and TH (intervention group) titrated between 32°C and 35°C to reduce ICP. ICP and PbtO2 were measured using the Licox system and core temperature was recorded through rectal thermometer. Data were analyzed at the hour before cooling, the first hour at target temperature, 2 consecutive hours at target temperature, and after 6 hours of hypothermia. There was a mean decrease in ICP of 4.3±1.6 mmHg (p<0.04) from 15.7 to 11.4 mmHg, from precooling to the first epoch of hypothermia in the intervention group (n=9) that was not seen in the control group (n=8). A decrease in ICP was maintained throughout all time periods. There was a mean decrease in PbtO2 of 7.8±3.1 mmHg (p<0.05) from 30.2 to 22.4 mmHg, from precooling to stable hypothermia, which was not seen in the control group. This research supports others in demonstrating a decrease in ICP with temperature, which could facilitate a reduction in the use of hyperosmolar agents or other stage II interventions. The decrease in PbtO2 is not below the suggested treatment threshold of 20 mmHg, but might indicate a decrease in CBF. PMID:26060880

  15. Effects of Different Fluid Regimes and Desmopressin on Uncontrolled Hemorrhage During Hypothermia in the Rat

    PubMed Central

    Heinius, Göran; Sondén, Anders

    2012-01-01

    Resuscitation with large volumes of crystalloids during traumatic hemorrhagic shock might increase the mortality by inducing rebleeding. However, few studies have addressed this problem during hypothermic conditions. Sixty-eight Sprague-Dawley rats were exposed to a standardized femoral artery injury and resuscitated with low (LRe), medium (MRe), or high (HRe) intensity using lactated Ringer's solution after being cooled to 30°C. An additional MRe group was also given desmopressin since this drug might reverse hypothermic-induced impairment of the primary hemostasis. The rats were rewarmed after 90 minutes and observed for 3 hours. The incidence, on-set time, duration, and volume of bleedings and hemodynamic changes were recorded. Rebleedings occurred in 60% of all animals and were more voluminous in the HRe group than in the LRe group (p=0.01). The total rebleeding volume per animal increased with the rate of fluid administration (r=0.50, p=0.01) and the duration of each rebleeding episode was longer in the HRe group than in the LRe group (p<0.001). However, the mortality tended to be higher in the LRe group (LRe=6/15, MRe=1/15, HRe=2/15, p=0.07). Desmopressin did not change the bled volume or the mortality. Overall, the mortality increased if rebleeding occurred (10/35 rebleeders died vs. 1/25 nonrebleeders, p=0.015). Liberal fluid administration increased the rebleeding volume while a trend toward higher mortality was seen with the restrictive fluid program. Desmopressin had no effect on the studied parameters. PMID:23667773

  16. Hepatic gene expression profiling of 5′-AMP-induced hypometabolism in mice

    PubMed Central

    Miki, Takao; Van Oort-Jansen, Anita; Matsumoto, Tomoko; Loose, David S.; Lee, Cheng Chi

    2011-01-01

    There is currently much interest in clinical applications of therapeutic hypothermia. Hypothermia can be a consequence of hypometabolism. We have recently established a procedure for the induction of a reversible deep hypometabolic state in mice using 5′-adenosine monophosphate (5′-AMP) in conjunction with moderate ambient temperature. The current study aims at investigating the impact of this technology at the gene expression level in a major metabolic organ, the liver. Our findings reveal that expression levels of the majority of genes in liver are not significantly altered by deep hypometabolism. However, among those affected by hypometabolism, more genes are differentially upregulated than downregulated both in a deep hypometabolic state and in the early arousal state. These altered gene expression levels during 5′-AMP induced hypometabolism are largely restored to normal levels within 2 days of the treatment. Our data also suggest that temporal control of circadian genes is largely stalled during deep hypometabolism. PMID:21224422

  17. Short-term hypothermia activates hepatic mitochondrial sn-glycerol-3-phosphate dehydrogenase and thermogenic systems.

    PubMed

    Bobyleva, V; Pazienza, L; Muscatello, U; Kneer, N; Lardy, H

    2000-08-15

    The contribution of the sn-glycerol-3-phosphate (G-3-P) shuttle in the control of energy metabolism is well established. It is also known that its activity may be modulated by hormones involved in thermogenesis, such as thyroid hormones or dehydroepiandrosterone and its metabolites, that act by inducing de novo synthesis of mitochondrial G-3-P dehydrogenase (mGPDH). However, little is known as to the factors that may influence the activity without enzyme induction. In the present study we investigated the possible role of the G-3-P shuttle in the thermogenic response to different hypothermic stresses. It was found that a decrease of body temperature causes the liver rapidly to enhance mGPDH activity and G-3-P-dependent respiration. The enhancement, which does not result from de novo synthesis of enzymes, has the potential of increasing heat production both by decreased ATP synthesis during the oxidation of G-3-P and by activation of the glycolytic pathway.

  18. A review of the use of early hypothermia in the treatment of traumatic brain injuries.

    PubMed

    Arcure, Jess; Harrison, Eric E

    2009-01-01

    Traumatic brain injury (TBI) is an assault to the brain that disrupts neurological activity. Known as the signature wound of combat during Operations Iraqi Freedom (OIF) and Enduing Freedom (OEF), it has become one of the most common injuries to American Soldiers. While affected Soldiers may remain stable after the primary injury, progressing secondary mechanisms can produce neurological degeneration. Hypothermic medicine is the treatment of injuries by cooling the core body temperature below normal physiological levels. Such treatment may be indicated to improve neurological outcomes after traumatic brain injuries by reducing the evolving secondary deterioration. To date, clinical trials have reached mixed conclusions. Trials have used unique temperature goals for treatment, different methods and times to reach such goals, and different durations at therapeutic temperature. Such variances in procedure and experimental populations have made it difficult to assess significance. In the article written by Markgraf et al. in 2001, research in animals showed the effect of hypothermic treatment within rats. Their results suggest that early initiation of hypothermic medicine after an induced traumatic brain injury (TBI) improved neurological outcomes when the body was cooled to 30 degrees Celsius (C) within four hours. An ongoing study by Clifton et al., on adults diagnosed with TBI, is examining the neurological outcome of early hypothermic medicine by centrally cooling the body to 33 degrees C and maintaining that temperature for 48 hours. While previous hypothermic devices were unable to cool rapidly, new technology allows achievement of the goal temperature within 20 minutes. Implementation of such new treatment may show an improvement in neurological outcomes for patients when treatment target temperature is reached within a four-hour window. We recommend that the use of hypothermic medicine should be re-evaluated for its indication in TBI due to the capabilities of

  19. Hypothermia and Platelet Dysfunction

    DTIC Science & Technology

    2007-11-02

    cardiopulmonary bypass during cardiac surgery, other major surgery, multiple trauma, cold exposure, and neonatal cold injury.1Ŗ The hemorrhagic diathesis...associated with hypothermic cardiopulmonary bypass during cardiac surgery is considered to be primarily a platelet function defect.I6,17,23 We have...cardiopulmonary bypass during cardiac surgery.,8,24 Consistent with this data, other investigators have recently reported that normothermic cardiopulmonary

  20. Hemodialysis-refractory metformin-associated lactate acidosis with hypoglycemia, hypothermia, and bradycardia in a diabetic patient with belated diagnosis and chronic kidney disease
.

    PubMed

    Zibar, Lada; Zibar, Karin

    2017-01-30

    Metformin is a first-line oral antidiabetic therapy for patients with type 2 diabetes mellitus. Metformin-associated lactate acidosis (MALA) is a well-known, life-threatening, but rare side effect of metformin therapy. Chronic kidney disease (CKD) patients have a much greater risk of MALA. We report the case of a severe refractory MALA despite hemodialysis (HD) treatment, associated with hypoglycemia, hypothermia, and bradycardia in a neglected and thus untimely-recognized CKD patient with type 2 diabetes mellitus. Despite the recent rehabilitation of metformin as a treatment of choice for type 2 diabetes mellitus, the drug should be prescribed with caution as it can be associated with life-threatening refractory acidosis, particularly in CKD patients. Moreover, HD treatment could occasionally be ineffective, resulting in a fatal outcome.
.

  1. Effects of combined xenon and hypothermia on cerebral blood flow and oxygen consumption in newborn piglets measured with a time-resolved near-infrared technique

    NASA Astrophysics Data System (ADS)

    Fazel Bakhsheshi, Mohammad; Hadway, Jennifer; Morrison, Laura B.; Diop, Mamadou; St. Lawrence, Keith; Lee, Ting-Yim

    2013-02-01

    Mild hypothermia (HT), in which the brain is cooled to 32-33°C, has been shown to be neuroprotective for neurological emergencies such as head trauma and neonatal asphyxia. Xenon (Xe), a scarce and expensive anesthetic gas, has also shown great promise as a neuroprotectant, particularly when combined with HT. The purpose of the present study was to investigate the combined effect of Xe and HT on the cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow (CBF). A closed circuit re-breathing system was used to deliver the Xe in order to make the treatment efficient and economical. A bolus-tracking method using indocyanine green (ICG) as a flow tracer with time-resolved near-infrared (TR-NIR) technique was used to measure CBF and CMRO2 in newborn piglets.

  2. Combination of veno-arterial extracorporeal membrane oxygenation and hypothermia for out-of-hospital cardiac arrest due to Taxus intoxication.

    PubMed

    Thooft, Aurélie; Goubella, Ahmed; Fagnoul, David; Taccone, Fabio S; Brimioulle, Serge; Vincent, Jean-Louis; De Backer, Daniel

    2014-11-01

    A young woman presented with cardiac arrest following ingestion of yew tree leaves of the Taxus baccata species. The toxin in yew tree leaves has negative inotropic and dromotropic effects. The patient had a cardiac rhythm that alternated between pulseless electrical activity with a prolonged QRS interval and ventricular fibrillation. When standard resuscitation therapy including digoxin immune Fab was ineffective, a combination of extracorporeal membrane oxygenation (ECMO) and hypothermia was initiated. The total duration of low flow/no flow was 82 minutes prior to the initiation of ECMO. After 36 hours of ECMO (including 12 hours of electrical asystole), the patient's electrocardiogram had normalized and the left ventricular ejection fraction was 50%. At this time, dobutamine and the ECMO were stopped. The patient had a full neurologic recovery and was discharged from the intensive care unit after 5 days and from the hospital 1 week later.

  3. Factors influencing survival of mammalian cells exposed to hypothermia. V. Effects of hepes, free radicals, and H sub 2 O sub 2 under light and dark conditions

    SciTech Connect

    Zieger, M.A.; Glofcheski, D.J.; Lepock, J.R.; Kruuv, J. )

    1991-02-01

    Cytotoxicity resulting from the interaction of fluorescent light from a flow hood with Hepes-buffered cell culture medium at room temperature was demonstrated. Toxicity was prevented by keeping both cells (V79 Chinese hamster) and medium shielded from direct fluorescent light ('dark conditions') or by supplementing the medium with 10 micrograms/ml catalase; this suggests that extracellular hydrogen peroxide is a major cause of the lethal effect under 'lighted conditions.' No sensitization resulted from the exposure of cells in a sodium bicarbonate (SBC)-buffered medium to fluorescent light, nor in a catalase supplemented SBC-buffered medium. The Hepes/light reaction during routine cell manipulations presensitized cells to hypothermia damage in the dark with the presensitization being more severe for 5 than for 10 degrees C hypothermic exposure. Presensitization was prevented by performing the complete experiment under dark conditions or by supplementing the medium with 10 micrograms/ml catalase. However, catalase did not improve the hypothermic survival when experiments were performed under dark conditions. Hence, 10 micrograms/ml catalase does not protect cells from hypothermic (5 and 10 degrees C) damage per se, but rather from Hepes/light sublethal damage which interacts with hypothermic sublethal damage to result in lethal lesions. Additionally, under dark conditions, superoxide dismutase (SOD), allopurinol, catalase plus SOD, DMSO, or mannitol did not improve survival when present during hypothermic storage, suggesting that extracellular superoxide anion, hydrogen peroxide, or hydroxyl radicals are not the cause of cell killing under conditions of pure hypothermia uncomplicated by prehypothermic ischemia or hypoxia.

  4. Near-Infrared Spectroscopy versus Magnetic Resonance Imaging To Study Brain Perfusion in Newborns with Hypoxic-Ischemic Encephalopathy Treated with Hypothermia

    PubMed Central

    Wintermark, P.; Hansen, A.; Warfield, SK.; Dukhovny, D.; Soul, JS.

    2014-01-01

    Background The measurement of brain perfusion may provide valuable information for assessment and treatment of newborns with hypoxic-ischemic encephalopathy (HIE). While arterial spin labeled perfusion (ASL) magnetic resonance imaging (MRI) provides noninvasive and direct measurements of regional cerebral blood flow (CBF) values, it is logistically challenging to obtain. Near-infrared spectroscopy (NIRS) might be an alternative, as it permits noninvasive and continuous monitoring of cerebral hemodynamics and oxygenation at the bedside. Objective The purpose of this study is to determine the correlation between measurements of brain perfusion by NIRS and by MRI in term newborns with HIE treated with hypothermia. Design/Methods In this prospective cohort study, ASL-MRI and NIRS performed during hypothermia were used to assess brain perfusion in these newborns. Regional cerebral blood flow values (CBF), measured from 1–2 MRI scans for each patient, were compared to mixed venous saturation values (SctO2) recorded by NIRS just before and after each MRI. Analysis included groupings into moderate versus severe HIE based on their initial background pattern of amplitude-integrated electroencephalogram. Results Twelve concomitant recordings were obtained of seven neonates. Strong correlation was found between SctO2 and CBF in asphyxiated newborns with severe HIE (r = 0.88; p value = 0.0085). Moreover, newborns with severe HIE had lower CBF (likely lower oxygen supply) and extracted less oxygen (likely lower oxygen demand or utilization) when comparing SctO2 and CBF to those with moderate HIE. Conclusions NIRS is an effective bedside tool to monitor and understand brain perfusion changes in term asphyxiated newborns, which in conjunction with precise measurements of CBF obtained by MRI at particular times, may help tailor neuroprotective strategies in term newborns with HIE. PMID:23631990

  5. Clinical Practice Variability in Temperature Correction of Arterial Blood Gas Measurements and Outcomes in Hypothermia-Treated Patients After Cardiac Arrest.

    PubMed

    Terman, Samuel Waller; Nicholas, Katherine S; Hume, Benjamin; Silbergleit, Robert

    2015-09-01

    Mechanical ventilation in patients treated with mild therapeutic hypothermia (MTH) for the postcardiac arrest syndrome may be challenging given changes in solubility of arterial blood gases (ABGs) with cooling. Whether ABG measurements should be temperature corrected (TC) remain unknown. We sought to describe practice variability in TC at a single institution and explored the association between TC and neurological outcome. We conducted a retrospective cohort study reviewing electronic health records of all patients treated with MTH after cardiac arrest. We examined whether the percentage of TC ABGs relative to total number of ABGs drawn for each subject during hypothermia was associated with the neurological outcome at hospital discharge and 6-12-month follow-up. The cerebral performance category of 1-2 was defined as a favorable outcome in the logistic regression models. 1223 ABGs were obtained during MTH on 122 subjects over 6 years. TC was never used in 72 subjects (59%; no TC group), made available in 1-74% of ABGs in 17 subjects (14%; intermediate TC group), and made available in ≥75% of ABGs in 33 subjects (27%; mostly TC group). Groups differed in the proportion of subjects with shockable presenting rhythms (47% vs. 47% vs. 76%, p=0.02) and admitting ICU (p=0.005). Favorable 6-month outcomes were more common in the mostly TC than no TC group (48% vs. 25%; OR [95% CI]: 2.9 [1.2-7.1]), but not after adjustment (OR 1.5, 95% CI 0.33-6.9). There was substantial practice variability in the temperature correction strategy. Availability of temperature-corrected ABGs was not associated with improved neurological outcomes after adjusting for covariates.

  6. Autonomic changes induced by provocative motion in rats bred for high (HAB) and low (LAB) anxiety-related behavior: Paradoxical responses in LAB animals.

    PubMed

    Carnevali, Luca; Andrews, Paul L; Neumann, Inga D; Nalivaiko, Eugene; Sgoifo, Andrea