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Williams, Ian D.
This experiment investigated the capability for movement and muscle spindle function at successive stages during the development of ischemic nerve block (INB) by pressure cuff. Two male subjects were observed under six randomly ordered conditions. The duration of index finger oscillation to exhaustion, paced at 1.2Hz., was observed on separate…
Williams, Ian D.
This experiment investigated the capability for movement and muscle spindle function at successive stages during the development of ischemic nerve block (INB) by pressure cuff. Two male subjects were observed under six randomly ordered conditions. The duration of index finger oscillation to exhaustion, paced at 1.2Hz., was observed on separate…
Hayek, Salim M; Shah, Atit
Nerve blocks are often performed as therapeutic or palliative interventions for pain relief. However, they are often performed for diagnostic or prognostic purposes. When considering nerve blocks for chronic pain, clinicians must always consider the indications, risks, benefits, and proper technique. Nerve blocks encompass a wide variety of interventional procedures. The most common nerve blocks for chronic pain and that may be applicable to the neurosurgical patient population are reviewed in this article. This article is an introduction and brief synopsis of the different available blocks that can be offered to a patient.
Pain syndromes in elderly patients are seldom psychogenic or due merely to "old age." Careful differential diagnosis is important, as judicious use of nerve blocks as adjunctive therapy often can relieve pain and restore activity. In the acute phase of shoulder pain, intrabursal injection of local anesthetic and steroid inhibits the inflammatory process. In the later stages, suprascapular nerve block relieves pain and interrupts afferent pain pathways. The occipital pain and headache of cervical arthritis also often respond to injection of 2 to 3 ml of long-acting anesthetic into the greater and lesser occipital nerves at the sites where they pierce the trapezius. Minor causalgia, shoulder-arm syndrome, or chronic traumatic edema may follow either forearm fracture or inflammation around the shoulder joint. Five stellate ganglion blocks with 1% lidocaine on alternate days, followed by 3 to 4 months of active and passive exercise, is the most effective treatment. This regimen usually produces a fully functional extremity. In degenerative disk disease, osteoarthritis, and metastatic disease, the cause of back pain is essentially the same--edema and inflammation of nerve roots at the intervertebral foramina. Injection of local anesthetic and steroid into the epidural space usually reduces swelling and inflammation. Patients are evaluated in 2 weeks and reblocked if improvement has plateaued. Pain relief most often is prompt and persists for an indefinite period.
Ahmed, Zulfiqar; Samad, Khalid; Ullah, Hameed
Background: The main advantages of video assisted thoracoscopic surgery (VATS) include less post-operative pain, rapid recovery, less postoperative complications, shorter hospital stay and early discharge. Although pain intensity is less as compared to conventional thoracotomy but still patients experience upto moderate pain postoperatively. The objective of this study was to assess the efficacy and morphine sparing effect of intercostal nerve block in alleviating immediate post-operative pain in patients undergoing VATS. Materials and Methods: Sixty ASA I-III patients, aged between 16 to 60 years, undergoing mediastinal lymph node biopsy through VATS under general anaesthesia were randomly divided into two groups. The intercostal nerve block (ICNB group) received the block along with patient control intravenous analgesia (PCIA) with morphine, while control group received only PCIA with morphine for post-operative analgesia. Patients were followed for twenty four hours post operatively for intervention of post-operative pain in the recovery room and ward. Results: The pain was assessed using visual analogue scale (VAS) at 1, 6, 12 and 24 hours. There was a significant decrease in pain score and morphine consumption in ICNB group as compared to control group in first 6 hours postoperatively. There was no significant difference in pain scores and morphine consumption between the two groups after 6 hours. Conclusion: Patients receiving intercostal nerve block have better pain control and less morphine consumption as compared to those patients who did not receive intercostal nerve block in early (6 hours) post-operative period. PMID:28217054
Ahmed, Zulfiqar; Samad, Khalid; Ullah, Hameed
The main advantages of video assisted thoracoscopic surgery (VATS) include less post-operative pain, rapid recovery, less postoperative complications, shorter hospital stay and early discharge. Although pain intensity is less as compared to conventional thoracotomy but still patients experience upto moderate pain postoperatively. The objective of this study was to assess the efficacy and morphine sparing effect of intercostal nerve block in alleviating immediate post-operative pain in patients undergoing VATS. Sixty ASA I-III patients, aged between 16 to 60 years, undergoing mediastinal lymph node biopsy through VATS under general anaesthesia were randomly divided into two groups. The intercostal nerve block (ICNB group) received the block along with patient control intravenous analgesia (PCIA) with morphine, while control group received only PCIA with morphine for post-operative analgesia. Patients were followed for twenty four hours post operatively for intervention of post-operative pain in the recovery room and ward. The pain was assessed using visual analogue scale (VAS) at 1, 6, 12 and 24 hours. There was a significant decrease in pain score and morphine consumption in ICNB group as compared to control group in first 6 hours postoperatively. There was no significant difference in pain scores and morphine consumption between the two groups after 6 hours. Patients receiving intercostal nerve block have better pain control and less morphine consumption as compared to those patients who did not receive intercostal nerve block in early (6 hours) post-operative period.
Thangavelu, K.; Kannan, R.; Kumar, N. Senthil
Background: Inferior alveolar nerve block (IANB) is a technique of dental anesthesia, used to produce anesthesia of the mandibular teeth, gingivae of the mandible and lower lip. The conventional IANB is the most commonly used the nerve block technique for achieving local anesthesia for mandibular surgical procedures. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. Therefore, it would be advantageous to find an alternative simple technique. Aim and Objective: The objective of this study is to find an alternative inferior alveolar nerve block that has a higher success rate than other routine techniques. To this purpose, a simple painless inferior alveolar nerve block was designed to anesthetize the inferior alveolar nerve. Materials and Methods: This study was conducted in Oral surgery department of Vinayaka Mission's dental college Salem from May 2009 to May 2011. Five hundred patients between the age of 20 years and 65 years who required extraction of teeth in mandible were included in the study. Out of 500 patients 270 were males and 230 were females. The effectiveness of the IANB was evaluated by using a sharp dental explorer in the regions innervated by the inferior alveolar, lingual, and buccal nerves after 3, 5, and 7 min, respectively. Conclusion: This study concludes that inferior alveolar nerve block is an appropriate alternative nerve block to anesthetize inferior alveolar nerve due to its several advantages. PMID:25885503
Sá, Miguel; Graça, Rita; Reis, Hugo; Cardoso, José Miguel; Sampaio, José; Pinheiro, Célia; Machado, Duarte
The superior gluteal nerve is responsible for innervating the gluteus medius, gluteus minimus and tensor fascia latae muscles, all of which can be injured during surgical procedures. We describe an ultrasound-guided approach to block the superior gluteal nerve which allowed us to provide efficient analgesia and anesthesia for two orthopedic procedures, in a patient who had significant risk factors for neuraxial techniques and deep peripheral nerve blocks. An 84-year-old female whose regular use of clopidogrel contraindicated neuraxial techniques or deep peripheral nerve blocks presented for urgent bipolar hemiarthroplasty in our hospital. Taking into consideration the surgical approach chosen by the orthopedic team, we set to use a combination of general anesthesia and superficial peripheral nerve blocks (femoral, lateral cutaneous of thigh and superior gluteal nerve) for the procedure. A month and a half post-discharge the patient was re-admitted for debriding and correction of suture dehiscence; we performed the same blocks and light sedation. She remained comfortable in both cases, and reported no pain in the post-operative period. Deep understanding of anatomy and innervation empowers anesthesiologists to solve potentially complex cases with safer, albeit creative, approaches. The relevance of this block in this case arises from its innervation of the gluteus medius muscle and posterolateral portion of the hip joint. To the best of our knowledge, this is the first report of an ultrasound-guided superior gluteal nerve block with an analgesic and anesthetic goal, which was successfully achieved. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.
Pudendal nerve block is a safe and effective pain relief method for vaginal birth. Providing analgesia to the vulva and anus, it is used for operative vaginal birth and subsequent repair, late second stage pain relief with spontaneous vaginal birth, repair of complex lacerations, or repair of lacerations in women who are unable to achieve adequate or satisfactory pain relief during perineal repair with local anesthesia. Key to its efficacy is the knowledge of pudendal nerve anatomy, the optimal point of infiltration of local anesthetic, and an understanding of the amount of time necessary to effect adequate analgesia.
Franke, Manfred; Vrabec, Tina; Wainright, Jesse; Bhadra, Niloy; Bhadra, Narendra; Kilgore, Kevin
Objective. Kilohertz frequency alternating current (KHFAC) waveforms have been shown to provide peripheral nerve conductivity block in many acute and chronic animal models. KHFAC nerve block could be used to address multiple disorders caused by neural over-activity, including blocking pain and spasticity. However, one drawback of KHFAC block is a transient activation of nerve fibers during the initiation of the nerve block, called the onset response. The objective of this study is to evaluate the feasibility of using charge balanced direct current (CBDC) waveforms to temporarily block motor nerve conductivity distally to the KHFAC electrodes to mitigate the block onset-response. Approach. A total of eight animals were used in this study. A set of four animals were used to assess feasibility and reproducibility of a combined KHFAC + CBDC block. A following randomized study, conducted on a second set of four animals, compared the onset response resulting from KHFAC alone and combined KHFAC + CBDC waveforms. To quantify the onset, peak forces and the force-time integral were measured during KHFAC block initiation. Nerve conductivity was monitored throughout the study by comparing muscle twitch forces evoked by supra-maximal stimulation proximal and distal to the block electrodes. Each animal of the randomized study received at least 300 s (range: 318-1563 s) of cumulative dc to investigate the impact of combined KHFAC + CBDC on nerve viability. Main results. The peak onset force was reduced significantly from 20.73 N (range: 18.6-26.5 N) with KHFAC alone to 0.45 N (range: 0.2-0.7 N) with the combined CBDC and KHFAC block waveform (p < 0.001). The area under the force curve was reduced from 6.8 Ns (range: 3.5-21.9 Ns) to 0.54 Ns (range: 0.18-0.86 Ns) (p < 0.01). No change in nerve conductivity was observed after application of the combined KHFAC + CBDC block relative to KHFAC waveforms. Significance. The distal application of CBDC can significantly reduce or even
Diéguez, P; Casas, P; López, S; Fajardo, M
The breast surgery has undergone changes in recent years, encouraging new initiatives for the anaesthetic management of these patients in order to achieve maximum quality and rapid recovery. The fundamental tool that has allowed a significant improvement in the progress of regional anaesthesia for breast disease has been ultrasound, boosting the description and introduction into clinical practice of interfascial chest wall blocks, although the reference standard is still the paravertebral block. It is very likely that these blocks will change the protocols in the coming years. A review is presented of the anatomy of the breast region, description of nerve blocks and techniques, as well as their indications, all according to published articles and the opinion of the authors based on their experience.
Guay, Joanne; Parker, Martyn J; Griffiths, Richard; Kopp, Sandra
Various nerve blocks with local anaesthetic agents have been used to reduce pain after hip fracture and subsequent surgery. This review was published originally in 1999 and was updated in 2001, 2002, 2009 and 2017. This review focuses on the use of peripheral nerves blocks as preoperative analgesia, as postoperative analgesia or as a supplement to general anaesthesia for hip fracture surgery. We undertook the update to look for new studies and to update the methods to reflect Cochrane standards. For the updated review, we searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8), MEDLINE (Ovid SP, 1966 to August week 1 2016), Embase (Ovid SP, 1988 to 2016 August week 1) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCO, 1982 to August week 1 2016), as well as trial registers and reference lists of relevant articles. We included randomized controlled trials (RCTs) involving use of nerve blocks as part of the care provided for adults aged 16 years and older with hip fracture. Two review authors independently assessed new trials for inclusion, determined trial quality using the Cochrane tool and extracted data. When appropriate, we pooled results of outcome measures. We rated the quality of evidence according to the GRADE Working Group approach. We included 31 trials (1760 participants; 897 randomized to peripheral nerve blocks and 863 to no regional blockade). Results of eight trials with 373 participants show that peripheral nerve blocks reduced pain on movement within 30 minutes of block placement (standardized mean difference (SMD) -1.41, 95% confidence interval (CI) -2.14 to -0.67; equivalent to -3.4 on a scale from 0 to 10; I(2) = 90%; high quality of evidence). Effect size was proportionate to the concentration of local anaesthetic used (P < 0.00001). Based on seven trials with 676 participants, we did not find a difference in the risk of acute confusional state (risk ratio (RR
Shah, Amit A; Nedeljkovic, Srdjan S
We report a previously undescribed complication associated with percutaneous maxillary nerve blockade. After the procedure, the patient reported an inability to close her ipsilateral eye (lagophthalmos). The patient had received 5 mL of 0.5% lidocaine for skin anesthesia. After needle placement was confirmed fluoroscopically, a combination of 80 mg methylprednisolone (2 mL) and 0.25% bupivacaine (3 mL) was administered. Symptoms resolved within 40 minutes. The likely cause was local anesthetic effect on the zygomatic branches of the facial nerve. When subcutaneous local anesthetic is given for maxillary block, smaller volumes should be considered. Doctors and patients should be aware of this complication, which may require treatment with artificial tears or patching of the eye to prevent corneal injury.
Vadhanan, Prasanna; Tripaty, Debendra Kumar; Adinarayanan, S.
A successful peripheral nerve block not only involves a proper technique, but also a thorough knowledge and understanding of the physiology of nerve conduction and pharmacology of local anesthetics (LAs). This article focuses on what happens after the block. Pharmacodynamics of LAs, underlying mechanisms of clinically observable phenomena such as differential blockade, tachyphylaxis, C fiber resistance, tonic and phasic blockade and effect of volume and concentration of LAs. Judicious use of additives along with LAs in peripheral nerve blocks can prolong analgesia. An entirely new group of drugs-neurotoxins has shown potential as local anesthetics. Various methods are available now to prolong the duration of peripheral nerve blocks. PMID:26330722
Vadhanan, Prasanna; Tripaty, Debendra Kumar; Adinarayanan, S
A successful peripheral nerve block not only involves a proper technique, but also a thorough knowledge and understanding of the physiology of nerve conduction and pharmacology of local anesthetics (LAs). This article focuses on what happens after the block. Pharmacodynamics of LAs, underlying mechanisms of clinically observable phenomena such as differential blockade, tachyphylaxis, C fiber resistance, tonic and phasic blockade and effect of volume and concentration of LAs. Judicious use of additives along with LAs in peripheral nerve blocks can prolong analgesia. An entirely new group of drugs-neurotoxins has shown potential as local anesthetics. Various methods are available now to prolong the duration of peripheral nerve blocks.
Boger, Adam; Bhadra, Narendra; Gustafson, Kenneth J.
Objective. We aim to evaluate the suitability of four electrodes previously used in clinical experiments for peripheral nerve electrical block applications. Approach. We evaluated peripheral nerve electrical block using three such clinical nerve cuff electrodes (the Huntington helix, the Case self-sizing Spiral and the flat interface nerve electrode) and one clinical intramuscular electrode (the Memberg electrode) in five cats. Amplitude thresholds for the block using 12 or 25 kHz voltage-controlled stimulation, onset response, and stimulation thresholds before and after block testing were determined. Main results. Complete nerve block was achieved reliably and the onset response to blocking stimulation was similar for all electrodes. Amplitude thresholds for the block were lowest for the Case Spiral electrode (4 ± 1 Vpp) and lower for the nerve cuff electrodes (7 ± 3 Vpp) than for the intramuscular electrode (26 ± 10 Vpp). A minor elevation in stimulation threshold and reduction in stimulus-evoked urethral pressure was observed during testing, but the effect was temporary and did not vary between electrodes. Significance. Multiple clinical electrodes appear suitable for neuroprostheses using peripheral nerve electrical block. The freedom to choose electrodes based on secondary criteria such as ease of implantation or cost should ease translation of electrical nerve block to clinical practice.
Boger, Adam; Bhadra, Narendra; Gustafson, Kenneth J
We aim to evaluate the suitability of four electrodes previously used in clinical experiments for peripheral nerve electrical block applications. We evaluated peripheral nerve electrical block using three such clinical nerve cuff electrodes (the Huntington helix, the Case self-sizing Spiral and the flat interface nerve electrode) and one clinical intramuscular electrode (the Memberg electrode) in five cats. Amplitude thresholds for the block using 12 or 25 kHz voltage-controlled stimulation, onset response, and stimulation thresholds before and after block testing were determined. Complete nerve block was achieved reliably and the onset response to blocking stimulation was similar for all electrodes. Amplitude thresholds for the block were lowest for the Case Spiral electrode (4 ± 1 Vpp) and lower for the nerve cuff electrodes (7 ± 3 Vpp) than for the intramuscular electrode (26 ± 10 Vpp). A minor elevation in stimulation threshold and reduction in stimulus-evoked urethral pressure was observed during testing, but the effect was temporary and did not vary between electrodes. Multiple clinical electrodes appear suitable for neuroprostheses using peripheral nerve electrical block. The freedom to choose electrodes based on secondary criteria such as ease of implantation or cost should ease translation of electrical nerve block to clinical practice.
Pogrel, M Anthony
Permanent nerve involvement has been reported following inferior alveolar nerve blocks. This study provides an update on cases reported to one unit in the preceding six years. Lidocaine was associated with 25 percent of cases, articaine with 33 percent of cases, and prilocaine with 34 percent of cases. It does appear that inferior alveolar nerve blocks can cause permanent nerve damage with any local anesthetic, but the incidences may vary.
Ince, Ilker; Aksoy, Mehmet; Celik, Mine
Objective: Distal nerve blocks are used in the event of unsuccessful blocks as rescue techniques. The primary purpose of this study was to determine the sufficiency for anesthesia of distal nerve block without the need for deep sedation or general anesthesia. The secondary purpose was to compare block performance times, block onset times, and patient and surgeon satisfaction. Materials and Methods: Patients who underwent hand surgery associated with the innervation area of the radial and median nerves were included in the study. Thirty-four patients who were 18–65 years old and American Society of Anesthesiologists grade I–III and who were scheduled for elective hand surgery under conscious nerve block anesthesia were randomly included in an infraclavicular block group (Group I, n=17) or a radial plus median block group (Group RM, n=17). The block performance time, block onset time, satisfaction of the patient and surgeon, and number of fentanyl administrations were recorded. Results: The numbers of patients who needed fentanyl administration and conversion to general anesthesia were the same in Group I and Group RM and there was no statistically significant difference (p>0.05). The demographics, surgery times, tourniquet times, block perfomance times, and patient and surgeon satisfaction of the groups were similar and there were no statistically significant differences (p>0.05). There was a statistically significant difference in block onset times between the groups (p<0.05). Conclusions: Conscious hand surgery can be performed under distal nerve block anesthesia safely and successfully. PMID:28149139
Urmey, W F
Conventional methodology for nerve location utilizes anatomical landmarks followed by invasive exploration with a needle to a suitable endpoint. An appropriate endpoint can be either anatomical in nature (e.g. transaterial technique) or functional (paresthesia or motor response to electrical stimulation). Ability to electrically stimulate a peripheral nerve or plexus depends upon many variables, including; 1) conductive area at the electrode, 2) electrical impedance, 3) electrode-to-nerve distance, 4) current flow (amperage), and 5) pulse duration. Electrode conductive area follows the equation R = rhoL/A, where R = electrical resistance, p = tissue resistivity, L = electrode-to-nerve distance, and A = electrode conductive area. Therefore resistance varies to the inverse of the electrode's conductive area. Tissue electrical impedance varies as a function of the tissue composition. In general, tissues with higher lipid content have higher impedances. Modern electrical nerve stimulators are designed to keep current constant, in spite of varying impedance. The electrode-to-nerve distance has the most influence on the ability to elicit a motor response to electrical stimulation. This is governed by Coulomb's law: E = K(Q/r2) where E = required stimulating charge, K= constant, Q = minimal required stimulating current, and r = electrode-to-nerve distance. Therefore, ability to stimulate the nerve at low amperage (e.g. < 0.5 mA), indicates an extremely close position to the nerve. Similarly, increasing current flow (amperage) increases the ability to stimulate the nerve at a distance. Increasing pulse duration increases the flow of electrons during a current pulse at any given amperage. Therefore, reducing pulse duration to very short times (e.g. 0.1 or 0.05 ms) diminishes current dispersion, requiring the needle tip to be extremely close to the nerve to elicit a motor response. The above parameters can be varied optimally to enhance successful nerve location and
Yilmaz, Eser; Hough, Karen A; Gebhart, Gerald F; Williams, Brian A; Gold, Michael S
The benzodiazepine midazolam has been reported to facilitate the actions of spinally administrated local anesthetics. Interestingly, despite the lack of convincing evidence for the presence of γ-aminobutyric acid type A (GABAA) receptors along peripheral nerve axons, midazolam also has been shown to have analgesic efficacy when applied alone to peripheral nerves.These observations suggest midazolam-induced nerve block is due to another site of action. Furthermore, because of evidence indicating that midazolam has equal potency at the benzodiazepine site on the GABAA receptor and the 18-kd translocator protein (TSPO), it is possible that at least the nerve-blocking actions of midazolam are mediated by this alternative site of action. We used the benzodiazepine receptor antagonist flumazenil, and the TSPO antagonist PK11195, with midazolam on rat sciatic nerves and isolated sensory neurons to determine if either receptor mediates midazolam-induced nerve block and/or neurotoxicity. Midazolam (300 μM)-induced block of nerve conduction was reversed by PK11195 (3 μM), but not flumazenil (30 μM). Midazolam-induced neurotoxicity was blocked by neither PK11195 nor flumazenil. Midazolam also causes the release of Ca from internal stores in sensory neurons, and there was a small but significant attenuation of midazolam-induced neurotoxicity by the Ca chelator, BAPTA. BAPTA (30 μM) significantly attenuated midazolam-induced nerve block. Our results indicate that processes underlying midazolam-induced nerve block and neurotoxicity are separable, and suggest that selective activation of TSPO may facilitate modality-selective nerve block while minimizing the potential for neurotoxicity.
Weyker, Paul David; Webb, Christopher Allen-John; Pham, Thoha M.
Neurological injuries following peripheral nerve blocks are a relatively rare yet potentially devastating complication depending on the type of lesion, affected extremity, and duration of symptoms. Medical management continues to be the treatment modality of choice with multimodal nonopioid analgesics as the cornerstone of this therapy. We report the case of a 28-year-old man who developed a clinical common peroneal and lateral sural cutaneous neuropathy following an uncomplicated popliteal sciatic nerve block. Workup with electrodiagnostic studies and magnetic resonance neurography revealed injury to both the femoral and sciatic nerves. Diagnostic studies and potential mechanisms for nerve injury are discussed. PMID:26904304
Patel, Yogi A; Butera, Robert J
Kilohertz electrical stimulation (KES) has been shown to induce repeatable and reversible nerve conduction block in animal models. In this study, we characterized the ability of KES stimuli to selectively block specific components of stimulated nerve activity using in vivo preparations of the rat sciatic and vagus nerves. KES stimuli in the frequency range of 5-70 kHz and amplitudes of 0.1-3.0 mA were applied. Compound action potentials were evoked using either electrical or sensory stimulation, and block of components was assessed through direct nerve recordings and muscle force measurements. Distinct observable components of the compound action potential had unique conduction block thresholds as a function of frequency of KES. The fast component, which includes motor activity, had a monotonically increasing block threshold as a function of the KES frequency. The slow component, which includes sensory activity, showed a nonmonotonic block threshold relationship with increasing KES frequency. The distinct trends with frequency of the two components enabled selective block of one component with an appropriate choice of frequency and amplitude. These trends in threshold of the two components were similar when studying electrical stimulation and responses of the sciatic nerve, electrical stimulation and responses of the vagus nerve, and sensorimotor stimulation and responses of the sciatic nerve. This differential blocking effect of KES on specific fibers can extend the applications of KES conduction block to selective block and stimulation of neural signals for neuromodulation as well as selective control of neural circuits underlying sensorimotor function.
Bhadra, Narendra; Bhadra, Niloy; Kilgore, Kevin; Gustafson, Kenneth J.
A reversible electrical block of the pudendal nerves may provide a valuable method for restoration of urinary voiding in individuals with bladder-sphincter dyssynergia. This study quantified the stimulus parameters and effectiveness of high frequency (HFAC) sinusoidal waveforms on the pudendal nerves to produce block of the external urethral sphincter (EUS). A proximal electrode on the pudendal nerve after its exit from the sciatic notch was used to apply low frequency stimuli to evoke EUS contractions. HFAC at frequencies from 1 to 30 kHz with amplitudes from 1 to 10 V were applied through a conforming tripolar nerve cuff electrode implanted distally. Sphincter responses were recorded with a catheter mounted micro-transducer. A fast onset and reversible motor block was obtained over this range of frequencies. The HFAC block showed three phases: a high onset response, often a period of repetitive firing and usually a steady state of complete or partial block. A complete EUS block was obtained in all animals. The block thresholds showed a linear relationship with frequency. HFAC pudendal nerve stimulation effectively produced a quickly reversible block of evoked urethral sphincter contractions. The HFAC pudendal block could be a valuable tool in the rehabilitation of bladder-sphincter dyssynergia.
Patel, Yogi A; Kim, Brian S; Rountree, William S; Butera, Robert J
Kilohertz electrical stimulation (KES) induces repeatable and reversible conduction block of nerve activity and is a potential therapeutic option for various diseases and disorders resulting from pathological or undesired neurological activity. However successful translation of KES nerve block to clinical applications is stymied by many unknowns such as the relevance of the onset response, acceptable levels of waveform contamination, and optimal electrode characteristics. We investigated the role of electrode geometric surface area on the KES nerve block threshold using 20 and 40 kHz current-controlled sinusoidal KES. Electrodes were electrochemically characterized and used to characterize typical KES waveforms and electrode charge characteristics. KES nerve block amplitudes, onset duration, and recovery of normal conduction after delivery of KES were evaluated along with power requirements for effective KES nerve block. Results from this investigation demonstrate that increasing electrode geometric surface area provides for a more power efficient KES nerve block. Reductions in block threshold by increased electrode surface area were found to be KESfrequency dependent, with block thresholds and average power consumption reduced by >2x with 20 kHz KES waveforms and >3x for 40 kHz KES waveforms.
Davies, T; Karanovic, S; Shergill, B
Following on from Part 1 of the series (regional nerve blocks for the face and scalp), we guide the clinician through the anatomy and cutaneous innervation of the digits, wrist and ankle, providing a practical step-by-step guide to regional nerve blockade of these areas.
Davies, T; Karanovic, S; Shergill, B
The aim of this two-part series is to provide an up-to-date review of essential regional nerve blocks for dermatological practice. In Part 1, we give a concise overview of local anaesthetics and their potential complications, as well as the relevant anatomy and cutaneous innervation of the face and scalp. This culminates in a step-by-step practical guide to performing each nerve block.
Kilgore, Kevin L.; Bhadra, Niloy
Objectives The features and clinical applications of balanced-charge kilohertz frequency alternating currents (KHFAC) are reviewed. Preclinical studies of KHFAC block have demonstrated that it can produce an extremely rapid and reversible block of nerve conduction. Recent systematic analysis and experimentation utilizing KHFAC block has resulted in a significant increase in interest in KHFAC block, both scientifically and clinically. Materials and Methods We review the history and characteristics of KHFAC block, the methods used to investigate this type of block, the experimental evaluation of block, and the electrical parameters and electrode designs needed to achieve successful block. We then analyze the existing clinical applications of high frequency currents, comparing the early results with the known features of KHFAC block. Results Although many features of KHFAC block have been characterized, there is still much that is unknown regarding the response of neural structures to rapidly fluctuating electrical fields. The clinical reports to date do not provide sufficient information to properly evaluate the mechanisms that result in successful or unsuccessful treatment. Conclusions KHFAC nerve block has significant potential as a means of controlling nerve activity for the purpose of treating disease. However, early clinical studies in the use of high frequency currents for the treatment of pain have not been designed to elucidate mechanisms or allow direct comparisons to preclinical data. We strongly encourage the careful reporting of the parameters utilized in these clinical studies, as well as the development of outcome measures that could illuminate the mechanisms of this modality. PMID:23924075
Deo, Saroj Prasad
Context: Dexamethasone has been frequently used in oral surgical procedure and accepted by oral and maxillofacial surgeon community worldwide. However, this is the first clinical trial that used dexamethasone as adjuvant with lignocaine in dental nerve block (DNB). Aims: The purpose of this double-blind, randomized control trial (RCT) was to compare the effect of dexamethasone with normal saline (NS) in a lignocaine DNB. Settings and Design: This prospective, double-blind, RCT was carried out after obtaining approval from the Institutional Ethical Committee. Subjects and Methods: In forty patients, the present placebo-controlled clinical trial was conducted; allocated randomly into two groups: study group (SG) or control group (CG). The single-dose submucosal dexamethasone or NS injection was administered immediately after 2% lignocaine with epinephrine 1:2,00,000 nerves block during mandibular third molar surgery (TMS). Visual analog scale score, number, and exact time nonsteroidal anti-inflammatory drugs were administered were used to measure postoperative analgesia in 2nd and 7th days. Statistical Analysis Used: All the data were entered into the Spreadsheet (Excel, Microsoft) and Chi-square test, Mann–Whitney U-test, Student's paired and unpaired t-test, and Fisher exact test were used. Results: This study found maximum duration of DNB in SG was 248.88 min and in CG was 175.44 min, whereas minimum duration in SG was 197 min and in CG was 140.78 min. Conclusions: Dexamethasone prolongs the action of lignocaine 2% in DNB for TMS. PMID:28299268
Patel, Yogi A.; Saxena, Tarun; Bellamkonda, Ravi V.; Butera, Robert J.
Efferent activation of the cervical vagus nerve (cVN) dampens systemic inflammatory processes, potentially modulating a wide-range of inflammatory pathological conditions. In contrast, afferent cVN activation amplifies systemic inflammatory processes, leading to activation of the hypothalamic-pituitary-adrenal (HPA) axis, the sympathetic nervous system through the greater splanchnic nerve (GSN), and elevation of pro-inflammatory cytokines. Ideally, to clinically implement anti-inflammatory therapy via cervical vagus nerve stimulation (cVNS) one should selectively activate the efferent pathway. Unfortunately, current implementations, in animal and clinical investigations, activate both afferent and efferent pathways. We paired cVNS with kilohertz electrical stimulation (KES) nerve block to preferentially activate efferent pathways while blocking afferent pathways. Selective efferent cVNS enhanced the anti-inflammatory effects of cVNS. Our results demonstrate that: (i) afferent, but not efferent, cVNS synchronously activates the GSN in a dose-dependent manner; (ii) efferent cVNS enabled by complete afferent KES nerve block enhances the anti-inflammatory benefits of cVNS; and (iii) incomplete afferent KES nerve block exacerbates systemic inflammation. Overall, these data demonstrate the utility of paired efferent cVNS and afferent KES nerve block for achieving selective efferent cVNS, specifically as it relates to neuromodulation of systemic inflammation. PMID:28054557
Objective To evaluate the prevalence of vulnerable blood vessels around cervical nerve roots before cervical nerve root block in the clinical setting. Methods This retrospective study included 74 patients with cervical radiculopathy who received an ultrasonography-guided nerve block at an outpatient clinic from July 2012 to July 2014. Before actual injection of the steroid was performed, we evaluated the vulnerable blood vessels around each C5, C6, and C7 nerve root of each patient's painful side, with Doppler ultrasound. Results Out of 74 cases, the C5 level had 2 blood vessels (2.7%), the C6 level had 4 blood vessels (5.45%), and the C7 level had 6 blood vessels (8.11%) close to each targeted nerve root. Moreover, the C5 level had 2 blood vessels (2.7%), the C6 level 5 blood vessels (6.75%), and the C7 level had 4 blood vessels (5.45%) at the site of an imaginary needle's projected pathway to the targeted nerve root, as revealed by axial transverse ultrasound imaging with color Doppler imaging. In total, the C5 level had 4 blood vessels (5.45%), the C6 level 9 blood vessels (12.16%), and the C7 level 10 had blood vessels (13.51%) either at the targeted nerve root or at the site of the imaginary needle's projected pathway to the targeted nerve root. There was an unneglectable prevalence of vulnerable blood vessels either at the targeted nerve root or at the site of the needle' projected pathway to the nerve root. Also, it shows a higher prevalence of vulnerable blood vessels either at the targeted nerve root or at the site of an imaginary needle's projected pathway to the nerve root as the spinal nerve root level gets lower. Conclusion To prevent unexpected critical complications involving vulnerable blood vessel injury during cervical nerve root block, it is recommended to routinely evaluate for the presence of vulnerable blood vessels around each cervical nerve root using Doppler ultrasound imaging before the cervical nerve root block, especially for the lower
Barbosa, Fabiano Timbó; Barbosa, Tatiana Rosa Bezerra Wanderley; da Cunha, Rafael Martins; Rodrigues, Amanda Karine Barros; Ramos, Fernando Wagner da Silva; de Sousa-Rodrigues, Célio Fernando
Recently, administration of sciatic nerve block has been revised due to the potential benefit for postoperative analgesia and patient satisfaction after the advent of ultrasound. The aim of this study was to describe the anatomical relations of the sciatic nerve in the popliteal fossa to determine the optimal distance the needle must be positioned in order to realize the sciatic nerve block anterior to its bifurcation into the tibial and common fibular nerve. The study was conducted by dissection of human cadavers' popliteal fossa, fixed in 10% formalin, from the Laboratory of Human Anatomy and Morphology Departments of the Universidade Federal de Alagoas and Universidade de Ciências da Saúde de Alagoas. Access to the sciatic nerve was obtained. 44 popliteal fossa were analyzed. The bifurcation of the sciatic nerve in relation to the apex of the fossa was observed. There was bifurcation in: 67.96% below the apex, 15.90% above the apex, 11.36% near the apex, and 4.78% in the gluteal region. The sciatic nerve bifurcation to its branches occurs at various levels, and the chance to succeed when the needle is placed between 5 and 7 cm above the popliteal is 95.22%. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.
Barbosa, Fabiano Timbó; Barbosa, Tatiana Rosa Bezerra Wanderley; Cunha, Rafael Martins da; Rodrigues, Amanda Karine Barros; Ramos, Fernando Wagner da Silva; Sousa-Rodrigues, Célio Fernando de
Recently, administration of sciatic nerve block has been revised due to the potential benefit for postoperative analgesia and patient satisfaction after the advent of ultrasound. The aim of this study was to describe the anatomical relations of the sciatic nerve in the popliteal fossa to determine the optimal distance the needle must be positioned in order to realize the sciatic nerve block anterior to its bifurcation into the tibial and common fibular nerve. The study was conducted by dissection of human cadavers' popliteal fossa, fixed in 10% formalin, from the Laboratory of Human Anatomy and Morphology Departments of the Universidade Federal de Alagoas and Universidade de Ciências da Saúde de Alagoas. Access to the sciatic nerve was obtained. 44 popliteal fossa were analyzed. The bifurcation of the sciatic nerve in relation to the apex of the fossa was observed. There was bifurcation in: 67.96% below the apex, 15.90% above the apex, 11.36% near the apex, and 4.78% in the gluteal region. The sciatic nerve bifurcation to its branches occurs at various levels, and the chance to succeed when the needle is placed between 5 and 7 cm above the popliteal is 95.22%. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.
Bariskaner, H; Ayaz, M; Guney, F B; Dalkilic, N; Guney, O
Unlike other drugs which act in the region of the synapse, local anesthetics are agents that reversibly block the generation and conduction of nerve impulses along a nerve fiber. This study aims to investigate the comparative inhibitions of bupivacaine and ropivacaine on the frog sciatic nerve. Isolated nerves were transferred to the nerve chamber which includes Ringer's solution. The nerves were stimulated by standard square wave pulse protocols and the responses were recorded with conventional systems. Bupivacaine (n = 8) and ropivacaine (n = 8) were administered in the nerve chamber bath with cumulative concentrations (10(-9) to 10(-3) M) and the effects were monitored for variable time periods (5, 10 and 15 min). Both bupivacaine and ropivacaine significantly depressed the compound action potential (CAP) parameters in a dose-dependent (p < 0.05) and reversible manner. Difference in the effects of these two drugs was detectable only when the dose (> or =10(-5) M) and exposure time (15 min) were increased. Percent inhibitions in maximum derivatives and latency-period measurements have shown that ropivacaine is not only fast but also much more powerful in conduction block for longer and higher doses. Bupivacaine, on the other hand, is effective in the group of fibers with relatively slower conduction velocity for all the measured doses and time periods. In conclusion, ropivacaine has a sensory specific side of action, when compared with the bupivacaine.
Santos Lasaosa, S; Cuadrado Pérez, M L; Guerrero Peral, A L; Huerta Villanueva, M; Porta-Etessam, J; Pozo-Rosich, P; Pareja, J A
Anaesthetic block, alone or in combination with other treatments, represents a therapeutic resource for treating different types of headaches. However, there is significant heterogeneity in patterns of use among different professionals. This consensus document has been drafted after a thorough review and analysis of the existing literature and our own clinical experience. The aim of this document is to serve as guidelines for professionals applying anaesthetic blocks. Recommendations are based on the levels of evidence of published studies on migraine, trigeminal autonomic cephalalgias, cervicogenic headache, and pericranial neuralgias. We describe the main technical and formal considerations of the different procedures, the potential adverse reactions, and the recommended approach. Anaesthetic block in patients with headache should always be individualised and based on a thorough medical history, a complete neurological examination, and expert technical execution. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.
d'Ovidio, Dario; Noviello, Emilio; Adami, Chiara
To describe the nerve stimulator-guided sciatic-femoral nerve block in raptors undergoing surgical treatment of pododermatitis. Prospective clinical trial. Five captive raptors (Falco peregrinus) aged 6.7 ± 1.3 years. Anaesthesia was induced and maintained with isoflurane in oxygen. The sciatic-femoral nerve block was performed with 2% lidocaine (0.05 mL kg(-1) per nerve) as the sole intra-operative analgesic treatment. Intraoperative physiological variables were recorded every 10 minutes from endotracheal intubation until the end of anaesthesia. Assessment of intraoperative nociception was based on changes in physiological variables above baseline values, while evaluation of postoperative pain relied on species-specific behavioural indicators. The sciatic-femoral nerve block was feasible in raptors and the motor responses following electrical stimulation of both nerves were consistent with those reported in mammalian species. During surgery no rescue analgesia was required. The anaesthesia plane was stable and cardiorespiratory variables did not increase significantly in response to surgical stimulation. Iatrogenic complications, namely nerve damage and local anaesthetic toxicity, did not occur. Recovery was smooth and uneventful. The duration (mean ± SD) of the analgesic effect provided by the nerve block was 130 ± 20 minutes. The sciatic-femoral nerve block as described in dogs and rabbits can be performed in raptors as well. Further clinical trials with a control groups are required to better investigate the analgesic efficacy and the safety of this technique in raptors. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.
Cuadrado, María-Luz; Gutiérrez-Viedma, Álvaro; Silva-Hernández, Lorenzo; Orviz, Aida; García-Moreno, Héctor
Our aim was to report three new cases of lacrimal neuralgia and their response to superficial nerve blocks. Lacrimal neuralgia has been recently described as a pain in the territory supplied by the lacrimal nerve, at the lateral upper eyelid and/or the adjacent area of the temple. The pain is typically accompanied by tenderness on palpation of the lacrimal nerve at the superoexternal angle of the orbit. Between January 2015 and June 2016, we prospective identified three cases of lacrimal neuralgia among the patients attending the Headache Unit in a tertiary hospital. Anesthetic blocks were performed in all cases by inserting a 30-G needle on the emergence of the nerve and injecting 0.5 cc of bupivacaine 0.5% subcutaneously. Three women aged 44, 49, and 51 presented with pain in the territory supplied by the lacrimal nerve. Two of them localized their pain in a small area of the right temple, while the remaining patient had pain in the right upper lateral eyelid and a small area of the lower lateral eyelid. The pain was continuous in two patients and episodic with attacks lasting 48 hours in one patient. All patients had tenderness on palpation of the lacrimal nerve. Anesthetic blocks confirmed the diagnosis of lacrimal neuralgia and provided the patients with long-lasting pain relief. Lacrimal neuralgia should be considered among the neuralgic causes of orbital and periorbital pain. Superficial nerve blocks may assist clinicians in the diagnosis and may also be a therapeutic option. © 2016 American Headache Society.
Sato, Masaki; Mikawa, Yasuhito; Matuda, Akiko
A selective lumbosacral nerve root block is generally is performed under X-ray fluoroscopy, which has the disadvantage of radiation exposure and the need for fluoroscopy equipment. In this study, we assessed the effectiveness of ultrasound and nerve stimulation-guided S1 nerve root block on 37 patients with S1 radicular syndrome. With the patient in a prone position, an ultrasound scan was performed by placing the probe parallel to the body axis. The needle was pointed slightly medial from the lateral side of the probe and advanced toward a hyperechoic area in the sacral foramina with ultrasound guidance. Contrast medium was then injected and its dispersion confirmed by fluoroscopy. The acquired contrast images were classified into intraneural, perineural, and paraneural patterns. The significance of differences in the effect of the block among the contrast image patterns was analyzed. After nerve block, decreased sensation at the S1 innervated region and pain relief was achieved in all patients. No significant difference was noted in the effect of the block between perineural and paraneural patterns. In conclusion, this technique provided reliable S1 nerve root block in patients with S1 radicular syndrome and minimized radiation exposure.
Porter, J. M.; Inglefield, C. J.
A prospective audit of 140 median, radial and ulnar blocks, given for 70 hand operations is described. The surgery was completed successfully in every patient. A further injection of local anaesthetic was required in 13 operations. Four patients experienced severe tourniquet pain. The results of the audit have shown that if a careful technique is used, a wide range of minor hand operations can be performed under regional nerve block. PMID:8215147
Forouzan, Arash; Masoumi, Kambiz; Motamed, Hasan; Gousheh, Mohammad Reza; Rohani, Akram
Introduction: Pain control is the most important issue in emergency department management of patients with femoral bone fractures. The present study aimed to compare the procedural features of ultrasonography and nerve stimulator guided femoral nerve block in this regard. Method: In this randomized clinical trial, patients with proximal femoral fractures presenting to emergency department were randomly divided into two groups of ultrasonography or nerve stimulator guided femoral block and compared regarding success rate, procedural time, block time, and need for rescue doses of morphine sulfate, using SPSS 20. Results: 50 patients were randomly divided into two groups of 25 (60% male). The mean age of studied patients was 35.14 ± 12.95 years (19 – 69). The two groups were similar regarding age (p= 0.788), sex (p = 0.564), and initial pain severity (p = 0.513). In 2 cases of nerve stimulator guided block, loss of pinprick sensation did not happen within 30 minutes of injection (success rate: 92%; p = 0.490). Ultrasonography guided nerve block cases had significantly lower procedural time (8.06 ± 1.92 vs 13.60 ± 4.56 minutes; p < 0.001) and lower need for rescue doses of opioid (2.68 ± 0.74 vs 5.28 ± 1.88 minutes; p < 0.001). Conclusion: Ultrasonography and nerve stimulator guided femoral block had the same success rate and block duration. However, the ultrasonography guided group had lower procedure time and lower need for rescue doses of morphine sulfate. Therefore, ultrasonography guided femoral block could be considered as an available, safe, rapid, and efficient method for pain management of femoral fracture in emergency department. PMID:28286861
This article discusses the various techniques that nurses can use to perform digital nerve blocks, which are some of the most common procedures undertaken by emergency practitioners treating patients with finger injuries. In covering the advantages and disadvantages of each technique, it focuses primarily on the digits of the hand, but the techniques can also be performed on toes.
Seeger, Trevor A; Orr, Serena; Bodell, Lisa; Lockyer, Lisette; Rajapakse, Thilinie; Barlow, Karen M
Posttraumatic headache is one of the most common and disabling symptoms after traumatic brain injury. However, evidence for treating posttraumatic headache is sparse, especially in the pediatric literature. This retrospective chart review evaluated the use of occipital nerve blocks in adolescents treated for posttraumatic headache following mild traumatic brain injury, presenting to the Complex Concussion and Traumatic Brain Injury clinic. Fifteen patients (mean age 15.47; range: 13-17) received occipital nerve block for posttraumatic headache. Follow-up was obtained in 14 patients at 5.57 (standard deviation = 3.52) months postinjury. The headache burden was high, with all except one having headaches 15 or more days per month (median 30, range 10-30). Sixty-four percent reported long-term response to the occipital nerve blocks, with associated improved quality of life and decreased postconcussion symptom scores (P < .05). One patient reported transient allopecia. Occipital nerve blocks are well tolerated and can be helpful in posttraumatic headache. © The Author(s) 2014.
Blezek, Daniel J.; Robb, Richard A.; Camp, Jon J.; Nauss, Lee A.; Martin, David P.
Deep nerve regional anesthesiology procedures, such as the celiac plexus block, are challenging to learn. The current training process primarily involves studying anatomy and practicing needle insertion is cadavers. Unfortunately, the training often continues on the first few patients subjected to the care of the new resident. To augment the training, we have developed a virtual reality surgical simulation designed to provide an immersive environment in which an understanding of the complex 3D relationships among the anatomic structures involved can be obtained and the mechanics of the celiac block procedure practiced under realistic conditions. Study of the relevant anatomy is provided by interactive 3D visualization of patient specific data nd the practice simulated using a head mounted display, a 6 degree of freedom tracker, and a haptic feedback device simulating the needle insertion. By training in a controlled environment, the resident may practice procedures repeatedly without the risks associated with actual patient procedures, and may become more adept and confident in the ability to perform nerve blocks. The resident may select a variety of different nerve block procedures to practice, and may place the virtual patient in any desired position and orientation. The preliminary anatomic models used in the simulation have been computed from the Visible Human Male; however, patient specific models may be generated from patient image data, allowing the physician to evaluate, plan, and practice difficult blocks and/or understand variations in anatomy before attempting the procedure on any specific patient.
Tzermpos, Fotios H; Cocos, Alina; Kleftogiannis, Matthaios; Zarakas, Marissa; Iatrou, Ioannis
Facial nerve palsy, as a complication of an inferior alveolar nerve block anesthesia, is a rarely reported incident. Based on the time elapsed, from the moment of the injection to the onset of the symptoms, the paralysis could be either immediate or delayed. The purpose of this article is to report a case of delayed facial palsy as a result of inferior alveolar nerve block, which occurred 24 hours after the anesthetic administration and subsided in about 8 weeks. The pathogenesis, treatment, and results of an 8-week follow-up for a 20-year-old patient referred to a private maxillofacial clinic are presented and discussed. The patient's previous medical history was unremarkable. On clinical examination the patient exhibited generalized weakness of the left side of her face with a flat and expressionless appearance, and she was unable to close her left eye. One day before the onset of the symptoms, the patient had visited her dentist for a routine restorative procedure on the lower left first molar and an inferior alveolar block anesthesia was administered. The patient's medical history, clinical appearance, and complete examinations led to the diagnosis of delayed facial nerve palsy. Although neurologic occurrences are rare, dentists should keep in mind that certain dental procedures, such as inferior alveolar block anesthesia, could initiate facial nerve palsy. Attention should be paid during the administration of the anesthetic solution.
Ackermann, D Michael; Ethier, Christian; Foldes, Emily L; Oby, Emily R; Tyler, Dustin; Bauman, Matt; Bhadra, Niloy; Miller, Lee; Kilgore, Kevin L
Recent studies have made significant progress toward the clinical implementation of high-frequency conduction block (HFB) of peripheral nerves. However, these studies were performed in small nerves, and questions remain regarding the nature of HFB in large-diameter nerves. This study in nonhuman primates shows reliable conduction block in large-diameter nerves (up to 4.1 mm) with relatively low-threshold current amplitude and only moderate nerve discharge prior to the onset of block.
Heschl, S; Hallmann, B; Zilke, T; Gemes, G; Schoerghuber, M; Auer-Grumbach, M; Quehenberger, F; Lirk, P; Hogan, Q; Rigaud, M
Peripheral nerve stimulation is commonly used for nerve localization in regional anaesthesia, but recommended stimulation currents of 0.3-0.5 mA do not reliably produce motor activity in the absence of intraneural needle placement. As this may be particularly true in patients with diabetic neuropathy, we examined the stimulation threshold in patients with and without diabetes. Preoperative evaluation included a neurological exam and electroneurography. During ultrasound-guided popliteal sciatic nerve block, we measured the current required to produce motor activity for the tibial and common peroneal nerve in diabetic and non-diabetic patients. Proximity to the nerve was evaluated post-hoc using ultrasound imaging. Average stimulation currents did not differ between diabetic (n=55) and non-diabetic patients (n=52). Although the planned number of patients was not reached, the power goal for the mean stimulation current was met. Subjects with diminished pressure perception showed increased thresholds for the common peroneal nerve (median 1.30 vs. 0.57 mA in subjects with normal perception, P=0.042), as did subjects with decreased pain sensation (1.60 vs. 0.50 mA in subjects with normal sensation, P=0.038). Slowed ulnar nerve conduction velocity predicted elevated mean stimulation current (r=-0.35, P=0.002). Finally, 15 diabetic patients required more than 0.5 mA to evoke a motor response, despite intraneural needle placement (n=4), or required currents ≥2 mA despite needle-nerve contact, vs three such patients (1 intraneural, 2 with ≥2 mA) among non-diabetic patients (P=0.003). These findings suggest that stimulation thresholds of 0.3-0.5 mA may not reliably determine close needle-nerve contact during popliteal sciatic nerve block, particularly in patients with diabetic neuropathy. NCT01488474. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia.
Mishra, Sobhan; Tripathy, Ramanupam; Sabhlok, Samrat; Panda, Pankaj Kumar; Patnaik, Satyabrata
Introduction: Over the years different techniques have been developed for achieving mandibular nerve anaesthesia. The main aim of our study was to carry out comparison and clinical efficacy of mandibular nerve anaesthesia by Direct Conventional technique with that of Vazirani-Akinosi mandibular nerve block technique.Materials and Methods: 50 adult patients requiring surgical extraction of premolars, mandibular first, second and third molars were selected randomly to receive Direct Conventional technique and Vazirani- Akinosi technique for nerve block alternatively.Results: No statistically significant differences were observed regarding complete lip anaesthesia at 5 minutes and 10 minutes, nerves anaesthetized with single injection, effectiveness of anaesthesia, supplementary injections and complications in both the techniques. However, onset of lip anaesthesia was found to be faster in Vazirani-Akinosi technique, patients experienced less pain during the Vazirani-Akinosi technique as compared to the Direct Conventional technique. Post injection complication complications were less in the VaziraniAkinosi Technique.Conclusions: Except for faster onset of lip anaesthesia, less pain during injection and fewer post injection complications in Vazirani-Akinosi technique all other parameters were of same efficacy as Direct Conventional technique. This has strong clinical applications as in cases with limited mouth opening, apprehensive patients Vazirani-Akinosi technique is the indicated technique of choice.
Davis, James Ch.; Ramirez, Jason G.
Peripheral nerve blocks present an alternative to general anesthesia in certain surgical procedures and a means of acute pain relief through continuous blockades. They have been shown to decrease the incidence of postoperative nausea and vomiting, reduce oral narcotic side effects, and improve sleep quality. Injecting needles, which carry small stimulating currents, are often used to aid in locating the target nerve bundle. With this technique, muscle responses indicate needle proximity to the corresponding nerve bundle. Failure rates in first injection attempts prompted our study of electric field distributions. Finite difference methods were used to solve for the electric fields generated by two widely used needles. Differences in geometry between needles are seen to effect changes in electric field and current distributions. Further investigations may suggest needle modifications that result in a reduction of initial probing failures.
Davis, James Ch.; Anderson, Norman E.; Meisel, Mark W.; Ramirez, Jason G.; Kayser Enneking, F.
Peripheral nerve blocks present an alternative to general anesthesia in certain surgical procedures and a means of acute pain relief through continuous blockades. They have been shown to decrease the incidence of postoperative nausea and vomiting, reduce oral narcotic side effects, and improve sleep quality. Injecting needles, which carry small stimulating currents, are often used to aid in locating the target nerve bundle. With this technique, muscle responses indicate needle proximity to the corresponding nerve bundle. Failure rates in first injection attempts prompted our study of electric field distributions. Finite difference methods were used to solve for the electric fields generated by two widely used needles. Geometric differences in the needles effect variations in their electric field and current distributions. Further investigations may suggest needle modifications that result in a reduction of initial probing failures.
Xu, Jin; Chen, Xue-Mei; Ma, Chen-Kai; Wang, Xiang-Rui
Major knee surgery is a common operative procedure to help people with end-stage knee disease or trauma to regain mobility and have improved quality of life. Poorly controlled pain immediately after surgery is still a key issue for this procedure. Peripheral nerve blocks are localized and site-specific analgesic options for major knee surgery. The increasing use of peripheral nerve blocks following major knee surgery requires the synthesis of evidence to evaluate its effectiveness and safety, when compared with systemic, local infiltration, epidural and spinal analgesia. To examine the efficacy and safety of peripheral nerve blocks for postoperative pain control following major knee surgery using methods that permit comparison with systemic, local infiltration, epidural and spinal analgesia. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 1, 2014), MEDLINE and EMBASE, from their inception to February 2014. We identified ongoing studies by searching trial registries, including the metaRegister of controlled trials (mRCT), clinicaltrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP). We included participant-blind, randomized controlled trials of adult participants (15 years or older) undergoing major knee surgery, in which peripheral nerve blocks were compared to systemic, local infiltration, epidural and spinal analgesia for postoperative pain relief. Two review authors independently assessed study eligibility and extracted data. We recorded information on participants, methods, interventions, outcomes (pain intensity, additional analgesic consumption, adverse events, knee range of motion, length of hospital stay, hospital costs, and participant satisfaction). We used the 5-point Oxford quality and validity scale to assess methodological quality, as well as criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions. We conducted meta-analysis of two or more studies with sufficient data
Ackermann, D Michael; Foldes, Emily L; Bhadra, Niloy; Kilgore, Kevin L
Conduction block of peripheral nerves is an important technique for many basic and applied neurophysiology studies. To date, there has not been a technique which provides a quickly initiated and reversible "on-demand" conduction block which is both sustainable for long periods of time and does not generate activity in the nerve at the onset of the conduction block. In this study we evaluated the feasibility of a combined method of nerve block which utilizes two well established nerve blocking techniques in a rat and cat model: nerve cooling and electrical block using high frequency alternating currents (HFAC). This combined method effectively makes use of the contrasting features of both nerve cooling and electrical block using HFAC. The conduction block was initiated using nerve cooling, a technique which does not produce nerve "onset response" firing, a prohibitive drawback of HFAC electrical block. The conduction block was then readily transitioned into an electrical block. A long-term electrical block is likely preferential to a long-term nerve cooling block because nerve cooling block generates large amounts of exhaust heat, does not allow for fiber diameter selectivity and is known to be unsafe for prolonged delivery.
Rodríguez, Jaime; Taboada, Manuel; Oliveira, Juan; Ulloa, Beatriz; Bascuas, Begoña; Alvarez, Julián
To compare the extent of sensory and motor block with two different nerve stimulation techniques in axillary blocks. Prospective, randomized, investigator-blinded study. Ambulatory surgery unit of a university hospital. 60 ASA physical status I, II, and III patients undergoing surgery at or below the elbow. Patients receiving axillary block were randomized into two nerve stimulation groups with either radial plus musculocutaneous or triple nerve stimulation (radial, median, and musculocutaneous nerves). Thirty milliliters of plain 2% mepivacaine was given to all patients either in a single or fractionated dosing for radial or for radial and median nerves, according to group assignment. Five milliliters of plain 1% mepivacaine for the musculocutaneous nerve was given to all patients. Blocks were assessed at 10, 20, and 30 minutes. Rates of supplementation given as a result of insufficient surgical anesthesia were also noted. Statistically significantly higher rates of anesthesia at the cutaneous distributions of median and medial cutaneous of the arm nerves with multiple nerve stimulation at 30 minutes were found as compared with radial plus musculocutaneous nerve stimulation. The rate of supplementation was lower with multiple nerve stimulation. Radial plus musculocutaneous nerve stimulation showed lower efficacy of axillary block than did triple nerve stimulation when using 2% mepivacaine.
Freedman, R R; Mayes, M D; Sabharwal, S C
Using a combination of environmental and local cooling, we induced vasospastic attacks of Raynaud's phenomenon in nine of 11 patients with idiopathic Raynaud's disease and in eight of 10 patients with scleroderma. Attacks were defined as occurring if two of the possible three color changes (pallor, cyanosis, and rubor) occurred, and serial photographs were scored by three independent raters. Two fingers on one hand were anesthetized by local injection of lidocaine, and the effectiveness of nerve blocks was verified by plethysmography. The frequency of vasospastic attacks in nerve-blocked fingers was not significantly different from that in the corresponding intact fingers on the contralateral hand. These findings show that the vasospastic attacks of Raynaud's disease and phenomenon can occur without the involvement of efferent digital nerves and argue against the etiologic role of sympathetic hyperactivity.
Thoracic paravertebral block (TPVB) is gaining popularity for female breast surgeries due to various advantages like less nausea and vomiting and better post-operative pain relief, which helps in early ambulation and discharge from the hospital. Use of nerve stimulator during this block has further enhanced its success and safety profile. Male breast surgery is usually done either under general anaesthesia or local infiltrative anaesthesia combining with intravenous sedation. We postulated that the advantages of TPVB could be helpful for early mobilization and discharge of minor breast surgery in male patients. However, to our knowledge, there is no such report suggestive of TPVB for exclusive male breast surgery. We used nerve stimulator-guided TPVB for gynecomastia surgery in two patients where general anaesthesia was not feasible. Both patients had successful block and showed good post-operative recovery and were discharged on the same day. They had long post-operative pain relief without any block-related complication. A case report of two such cases of gynecomastia surgery (male breast surgery) done under TPVB is presented. PMID:22923833
Thoracic paravertebral block (TPVB) is gaining popularity for female breast surgeries due to various advantages like less nausea and vomiting and better post-operative pain relief, which helps in early ambulation and discharge from the hospital. Use of nerve stimulator during this block has further enhanced its success and safety profile. Male breast surgery is usually done either under general anaesthesia or local infiltrative anaesthesia combining with intravenous sedation. We postulated that the advantages of TPVB could be helpful for early mobilization and discharge of minor breast surgery in male patients. However, to our knowledge, there is no such report suggestive of TPVB for exclusive male breast surgery. We used nerve stimulator-guided TPVB for gynecomastia surgery in two patients where general anaesthesia was not feasible. Both patients had successful block and showed good post-operative recovery and were discharged on the same day. They had long post-operative pain relief without any block-related complication. A case report of two such cases of gynecomastia surgery (male breast surgery) done under TPVB is presented.
Malamed, Stanley F
Providing effective pain control is a critical part of dental treatment, yet achieving consistently reliable anesthesia in the mandible has proved elusive. The traditional inferior alveolar nerve block (IANB) has a high failure rate; for example, the failure rate in lateral incisors is 81 percent. As a consequence, new approaches and techniques have been developed. The purpose of this supplement to The Journal of the American Dental Association is to determine whether the mandibular nerve block has become passé. The high failure rate of the IANB can be frustrating for dentists and lead to discomfort for the patient during treatment. The reasons for this high failure rate include thickness of the cortical plate of bone in adults, thickness of the soft tissue at the injection site leading to increased needle deflection, the difficulty of locating the inferior alveolar nerve and the possibility of accessory innervation. Although the IANB can be unreliable, it is used commonly to provide mandibular anesthesia. Pain control is an essential part of dental treatment. Alternative injection techniques and devices that can help increase the success rate of mandibular anesthesia are available.
Hung, Ming-Hui; Hsu, Hsao-Hsun; Chan, Kuang-Cheng; Chen, Ke-Cheng; Yie, Jr-Chi; Cheng, Ya-Jung; Chen, Jin-Shing
Thoracoscopic surgery using internal intercostal nerve block, vagal block and targeted sedation without endotracheal intubation is a promising technique for selected patients, but little is known about its feasibility and safety. We evaluated 109 patients with lung (105), mediastinal (3) or pleural (1) tumours treated using non-intubated thoracoscopic surgery. Internal, intercostal nerve block was performed at the T3-T8 intercostal level and vagal block was performed adjacent to the vagus nerve at the level of the lower trachea for right-sided operations and at the level of the aortopulmonary window for left-sided operations. Sedation was performed with propofol infusion to achieve a bispectral index value between 40 and 60. Thoracoscopic lobectomy was performed in 43 patients, wedge resection in 50, segmentectomy in 12 and mediastinal or pleural tumour excision in 4. Three patients (2.8%) required conversion to intubated one-lung ventilation because of vigorous mediastinal movement and dense diaphragmatic adhesions. Anaesthetic induction and operation had a median duration of 10.0 and 127.0 min, respectively. Operative complications developed in 13 patients with air leaks for more than 3 days and 1 patient required transfusion of blood products. The median postoperative chest drainage and hospital stay were 2.0 and 4.0 days, respectively. Non-intubated thoracoscopic surgery using internal intercostal nerve block, vagal block and targeted sedation is technically feasible and safe in surgical treatment of lung, mediastinal and pleural tumours in selected patients. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
So, MinHye; Sugiura, Takeshi; Yoshizawa, Saya; Sobue, Kazuya
In recent years, the technique of combined ultrasound and electrical stimulation-guided nerve block has been recommended. We present 2 patients with Duchenne muscular dystrophy who exhibited different muscle responses to nerve stimulation during the performance of peripheral nerve blocks for surgeries. Whereas a 2-year-old boy without severe disability showed the expected muscle contraction to electrical nerve stimulation, a 14-year-old boy with severe disability showed no muscle response. Our experience suggests that muscle responses to electrical nerve stimulation will vary with the stage of Duchenne muscular dystrophy.
Aubuchon, Adam; Arnold, W David; Bracewell, Anna; Hoyle, J Chad
Sciatic neuropathy after popliteal nerve block (PNB) for regional anesthesia is considered uncommon but has been increasingly recognized in the literature. We identified a case of sciatic neuropathy that occurred after bunionectomy during which a PNB had been performed. To understand the frequency of PNB-related sciatic neuropathy, we performed a retrospective review of sciatic neuropathies at our center over a 5-year period. Forty-five cases of sciatic neuropathy were reviewed. Similar to earlier reports, common etiologies of sciatic neuropathy, including compression, trauma, fractures, and hip arthroplasty, were noted in the majority of our cases (60%, n = 27). Unexpectedly, PNB was the third most common etiology (16%, n = 7). Our results suggest PNB is a relatively common etiology of sciatic neuropathy and is an important consideration in the differential diagnosis. These findings should urge electromyographers to assess history of PNB in sciatic neuropathies, particularly with onset after surgery. Muscle Nerve 56: 822-824, 2017. © 2017 Wiley Periodicals, Inc.
Inan, Nurten; Inan, Levent E; Coşkun, Özlem; Tunç, Tuğba; Ilhan, Mustafa
Peripheral nerve blocks have been used in primary headache treatment since a long time. In this study, we aimed to examine the efficiency of greater occipital nerve (GON) block in migraine prophylaxis. Data from migraine without aura patients who had GON block were collected and divided into two groups: Group PGON (n=25), which included patients who were under medical prophylaxis and had GON block, and Group GON (n=53), which included patients who had only GON blocks. Migraine was diagnosed using International Headache Society (IHS) classification. Data of 78 patients were analyzed. Headache attack frequency, headache duration, and severity were compared between and within groups in a 3-month follow-up period. The decrease in headache parameters after GON block in both groups was significantly similar. Headache attack frequency decreased from 15.73±7.21 (pretreatment) to 4.52±3.61 (3rd month) in Group GON and from 13.76±8.07 to 3.28±2.15 in Group PGON (p<0.05). Headache duration decreased from 18.51±9.43 to 8.02±5.58 at 3rd month in Group GON and from 15.20±9.16 to 7.20±4.16 in Group PGON (p<0.05). Headache severity decreased from 8.26±1.32 to 5.16±2.64 in Group GON and from 8.08±0.90 to 5.96±1.20 in Group PGON (p<0.05). There was no statistically significant difference between the groups in 3rd month after treatment (p>0.05). This study showed significant decreases in headache parameters in both groups. As GON blocks were performed in patients unresponsive to medical prophylaxis, a decrease in the headache parameters in Group PGON similar to that in Group GON can be attributed to GON blocks. Consequently, these results show that repeated GON blocks with local anesthetic can be an effective alternative treatment in migraine patients who are unresponsive to medical prophylaxis or who do not prefer to use medical prophylaxis.
İNAN, Nurten; İNAN, Levent E.; COŞKUN, Özlem; TUNÇ, Tuğba; İLHAN, Mustafa
Introduction Peripheral nerve blocks have been used in primary headache treatment since a long time. In this study, we aimed to examine the efficiency of greater occipital nerve (GON) block in migraine prophylaxis. Methods Data from migraine without aura patients who had GON block were collected and divided into two groups: Group PGON (n=25), which included patients who were under medical prophylaxis and had GON block, and Group GON (n=53), which included patients who had only GON blocks. Migraine was diagnosed using International Headache Society (IHS) classification. Data of 78 patients were analyzed. Headache attack frequency, headache duration, and severity were compared between and within groups in a 3-month follow-up period. Results The decrease in headache parameters after GON block in both groups was significantly similar. Headache attack frequency decreased from 15.73±7.21 (pretreatment) to 4.52±3.61 (3rd month) in Group GON and from 13.76±8.07 to 3.28±2.15 in Group PGON (p<0.05). Headache duration decreased from 18.51±9.43 to 8.02±5.58 at 3rd month in Group GON and from 15.20±9.16 to 7.20±4.16 in Group PGON (p<0.05). Headache severity decreased from 8.26±1.32 to 5.16±2.64 in Group GON and from 8.08±0.90 to 5.96±1.20 in Group PGON (p<0.05). There was no statistically significant difference between the groups in 3rd month after treatment (p>0.05). Conclusion This study showed significant decreases in headache parameters in both groups. As GON blocks were performed in patients unresponsive to medical prophylaxis, a decrease in the headache parameters in Group PGON similar to that in Group GON can be attributed to GON blocks. Consequently, these results show that repeated GON blocks with local anesthetic can be an effective alternative treatment in migraine patients who are unresponsive to medical prophylaxis or who do not prefer to use medical prophylaxis. PMID:28360765
Schmutz, M; Schumacher, P M; Luyet, C; Curatolo, M; Eichenberger, U
Ilioinguinal (IL) and iliohypogastric (IH) nerve blocks are used in patients with chronic postherniorrhaphy pain. The present study tested the hypothesis that our method, previously developed in cadavers, blocks the nerves separately and selectively in human volunteers. We blocked the IL and the IH nerves in 16 volunteers in a single-blinded randomized cross-over setting under direct ultrasound visualization, by injecting two times the ED95 volume of 1% mepivacaine needed to block a peripheral nerve. The anaesthetized skin areas were tested by pinprick and marked on the skin. A digital photo was taken. For further analysis, the parameterized picture data were transformed into a standardized and unified coordinate system to compare and calculate the overlap of the anaesthetized skin areas of the two nerves on each side. An overlap <25% was defined as selective block. Fifty nerve blocks could be analysed. The mean volume injected to block a single nerve was 0.9 ml. Using ultrasound, we observed spread from one nerve to the other in 12% of cases. The overlap of the anaesthetized skin areas of the nerves was 60.3% and did not differ after exclusion of the cases with visible spread of local anaesthetic from one nerve to the other. The IL and IH nerves cannot be selectively blocked even if volumes below 1 ml are used. The most likely explanation is the spread of local anaesthetic from one nerve to the other, although this could not be directly observed in most cases.
Rigaud, J; Delavierre, D; Sibert, L; Labat, J-J
The autonomic sympathetic nervous system conveys nociceptive messages from the viscera to the brain. The purpose of this article is to review the place of autonomic nerve blocks in the management of chronic pelvic and perineal pain. A comprehensive review of the literature was performed by searching PubMed for articles on autonomic nerve blocks and related procedures in the management of chronic pelvic and perineal pain. Intervention on the sympathetic nervous system for the management of chronic pelvic and perineal pain has been proposed at main three levels: ganglion Impar, hypogastric plexus and L2 lumbar sympathetic blocks. Infiltration of the sympathetic nervous system with local anaesthetic constitutes a diagnostic test by providing pain relief for the duration of action of the local anaesthetic in two third of patients. Specific procedures have been performed such as alcohol nerve block, radiofrequency ablation, surgical section or botulinum toxin infiltration at these various sites to achieve more lasting results. A sympathetic nervous system test block plays a diagnostic role in the management of chronic pelvic and perineal pain by guiding more specific global pain management procedures. Copyright © 2010 Elsevier Masson SAS. All rights reserved.
Guay, Joanne; Parker, Martyn J; Griffiths, Richard; Kopp, Sandra L
This review focuses on the use of peripheral nerve blocks as preoperative analgesia, as postoperative analgesia, or as a supplement to general anesthesia for hip fracture surgery and tries to determine if they offer any benefit in terms of pain on movement at 30 minutes after block placement, acute confusional state, myocardial infarction/ischemia, pneumonia, mortality, time to first mobilization, and cost of analgesic. Trials were identified by computerized searches of Cochrane Central Register of Controlled Trials (2016, Issue 8), MEDLINE (Ovid SP, 1966 to 2016 August week 1), Embase (Ovid SP, 1988 to 2016 August week 1), and the Cumulative Index to Nursing and Allied Health Literature (EBSCO, 1982 to 2016 August week 1), trials registers, and reference lists of relevant articles. Randomized controlled trials involving the use of nerve blocks as part of the care for hip fractures in adults aged 16 years and older were included. The quality of the studies was rated according to the Cochrane tool. Two authors independently extracted the data. The quality of evidence was judged according to the Grading of Recommendations, Assessment, Development, and Evaluations Working Group scale. Based on 8 trials with 373 participants, peripheral nerve blocks reduced pain on movement within 30 minutes of block placement: standardized mean difference, -1.41 (95% confidence interval [CI], -2.14 to -0.67; equivalent to -3.4 on a scale from 0 to 10; I statistic = 90%; high quality of evidence). The effect size was proportional to the concentration of local anesthetic used (P < .00001). Based on 7 trials with 676 participants, no difference was found in the risk of acute confusional state: risk ratio, 0.69 (95% CI, 0.38-1.27; I statistic = 48%; very low quality of evidence). Based on 3 trials with 131 participants, the risk for pneumonia was decreased: risk ratio, 0.41 (95% CI, 0.19-0.89; I statistic = 3%; number needed-to-treat for additional beneficial outcome, 7 [95% CI, 5
Yoon, Seok-Hwa; Kim, Bum June; Song, Seunghyun; Yoon, Yeomyung
Regional anesthesia for non-obstetric surgery in parturients is a method to decrease patient and fetal risk during general anesthesia. Thoracic interfascial nerve block can be used as an analgesic technique for surgical procedures of the thorax. The Pecs II block is an interfascial block that targets not only the medial and lateral pectoral nerves, but also the lateral cutaneous branch of the intercostal nerve. Pecto-intercostal fascial block (PIFB) targets the anterior cutaneous branch of the intercostal nerve. The authors successfully performed a modified Pecs II block and PIFB without complications in a parturient who refused general anesthesia for breast surgery. PMID:28367293
Santos Lasaosa, S; Gago Veiga, A; Guerrero Peral, Á L; Viguera Romero, J; Pozo-Rosich, P
Anaesthetic blocks, whether used alone or combined with other treatments, are a therapeutic resource for many patients with headaches. However, usage patterns by different professionals show significant heterogeneity. The Headache Study Group of the Spanish Society of Neurology (GECSEN) designed a self-administered cross-sectional survey and sent it to all group members through the SEN's scientific area web platform in February 2016. The objective was to ascertain the main technical and formal aspects of this procedure and compare them with data obtained in a similar survey conducted in 2012. A total of 39 neurologists (mean age 41.74 years; SD: 9.73), 23 men (43.7 years; SD: 9.92) and 16 women (38.94 years; SD: 9.01) participated in this survey. Of these respondents, 76.9% used anaesthetic block in their clinical practice (79.16% in a tertiary-care hospital). The main indications were diagnosis and treatment of neuralgia (100%), prevention of chronic migraine (61.7%), episodic cluster headache (51.3%), and chronic cluster headache (66.7%). AB was used by 31% of the respondents to block only the lateral occipital complex, 13% also infiltrated the supraorbital nerve, and another 13% infiltrated the auriculotemporal nerve as well. The indications for anaesthetic blocks and the territories most frequently infiltrated are similar to those cited in the earlier survey. However, we observed increased participation in this latest survey and a higher percentage of young neurologists (35.89% aged 35 or younger), indicating that use of this technique has entered mainstream clinical practice. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.
Management of intractable cancer-associated chest wall pain is difficult once patients have reached dose-limiting side effects of opioids and coanalgesic medications. This case series describes 11 patients with intractable cancer-associated chest wall pain who were treated with a diagnostic intercostal nerve block. Six patients subsequently received chemical neurolysis with phenol using the same approach. No serious adverse events were observed. Radiopaque contrast dye spread into the paravertebral space in all 11 patients, and in 1 patient contrast dye spread into the epidural space. Seven of 11 patients experienced pain relief from the diagnostic blockade. Four of six patients experienced pain relief from the neurolytic blockade. The principal reportable finding from this case series is the observation that contrast dye spread liberally from the intercostal space into other anatomic spaces, even though very small volumes of injectate (less than 5 mL) were used. Definitive evidence of safety and efficacy of intercostal nerve block and neurolysis for cancer pain will require a prospective randomized clinical trial.
Finn, Daphna M; Agarwal, Rishi R; Ilfeld, Brian M; Madison, Sarah J; Ball, Scott T; Ferguson, Eliza J; Morgan, Anya C; Morris, Beverly A
Combined scientific advances in pharmaceutical agents, perineural blocks, and pump delivery capabilities such as those used with continuous peripheral nerve blocks have demonstrated advantages in pain management for patients undergoing joint arthroplasty. This report documents the incidence of falls increased after the implementation of a continuous peripheral nerve block program for patients undergoing knee and hip arthroplasty in an academic medical center.
PALTI, Dafna Geller; de ALMEIDA, Cristiane Machado; RODRIGUES, Antonio de Castro; ANDREO, Jesus Carlos; LIMA, José Eduardo Oliveira
Background Effective pain control in Dentistry may be achieved by local anesthetic techniques. The success of the anesthetic technique in mandibular structures depends on the proximity of the needle tip to the mandibular foramen at the moment of anesthetic injection into the pterygomandibular region. Two techniques are available to reach the inferior alveolar nerve where it enters the mandibular canal, namely indirect and direct; these techniques differ in the number of movements required. Data demonstrate that the indirect technique is considered ineffective in 15% of cases and the direct technique in 1329% of cases. Objective Objective: The aim of this study was to describe an alternative technique for inferior alveolar nerve block using several anatomical points for reference, simplifying the procedure and enabling greater success and a more rapid learning curve. Materials and Methods A total of 193 mandibles (146 with permanent dentition and 47 with primary dentition) from dry skulls were used to establish a relationship between the teeth and the mandibular foramen. By using two wires, the first passing through the mesiobuccal groove and middle point of the mesial slope of the distolingual cusp of the primary second molar or permanent first molar (right side), and the second following the oclusal plane (left side), a line can be achieved whose projection coincides with the left mandibular foramen. Results The obtained data showed correlation in 82.88% of cases using the permanent first molar, and in 93.62% of cases using the primary second molar. Conclusion This method is potentially effective for inferior alveolar nerve block, especially in Pediatric Dentistry. PMID:21437463
Yin, Z; Gu, Y; Shen, L; Dong, Y
To clinically evaluate the protective effect of procaine blocking on nerves. Electrophysiological examination before and after procaine blocking was conducted on 32 nerves during operation, 18 of which were donor nerves and 14 were injured ones. The latency of somatosensory evoked potentials (SEPs) was lengthened (15.30%) and the amplitude was lowered (18.47) after procaine blocking. Compared with the values before procaine blocking, the differences were significant (P < 0.01 and P < 0.05, respectively). SEP waves disappeared after procaine blocking in some cases (28.13%). Latency of SEP is lengthened and amplitude is lowered after procaine blocking. In some cases, SEPs even disappear.
Wedlake, Chris; Moore, John; Rachinsky, Maxim; Bainbridge, Daniel; Wiles, Andrew D.; Peters, Terry M.
Peripheral nerve block treatments are ubiquitous in hospitals and pain clinics worldwide. State of the art techniques use ultrasound (US) guidance and/or electrical stimulation to verify needle tip location. However, problems such as needle-US beam alignment, poor echogenicity of block needles and US beam thickness can make it difficult for the anesthetist to know the exact needle tip location. Inaccurate therapy delivery raises obvious safety and efficacy issues. We have developed and evaluated a needle guidance system that makes use of a magnetic tracking system (MTS) to provide an augmented reality (AR) guidance platform to accurately localize the needle tip as well as its projected trajectory. Five anesthetists and five novices performed simulated nerve block deliveries in a polyvinyl alcohol phantom to compare needle guidance under US alone to US placed in our AR environment. Our phantom study demonstrated a decrease in targeting attempts, decrease in contacting of critical structures, and an increase in accuracy of 0.68 mm compared to 1.34mm RMS in US guidance alone. Currently, the MTS uses 18 and 21 gauge hypodermic needles with a 5 degree of freedom sensor located at the needle tip. These needles can only be sterilized using an ethylene oxide process. In the interest of providing clinicians with a simple and efficient guidance system, we also evaluated attaching the sensor at the needle hub as a simple clip-on device. To do this, we simultaneously performed a needle bending study to assess the reliability of a hub-based sensor.
Messeha, Medhat M.
Background: Lumbar plexus block, combined with a sciatic nerve block, is an effective locoregional anesthetic technique for analgesia and anesthesia of the lower extremity. The aim of this study was to compare the clinical results outcome of the adductor canal block versus the psoas compartment block combined with sciatic nerve block using real time ultrasound guidance in patients undergoing elective laparoscopic knee surgeries. Patients and Methods: Ninety patients who were undergoing elective laparoscopic knee surgeries were randomly allocated to receive a sciatic nerve block in addition to lumbar plexus block using either an adductor canal block (ACB) or a posterior psoas compartment approach (PCB) using 25 ml of bupivacine 0.5% with adrenaline 1:400,000 injection over 2-3 minutes while observing the distribution of the local anesthetic in real time. Successful nerve block was defined as a complete loss of pinprick sensation in the region that is supplied by the three nerves along with adequate motor block, 30 minutes after injection. The degree of motor block was evaluated 30 minutes after the block procedure. The results of the present study showed that the real time ultrasound guidance of PCB is more effective than ACB approach. Although the sensory blockade of the femoral nerve achieved equally by both techniques, the LFC and OBT nerves were faster and more effectively blocked with PCB technique. Also PCB group showed significant complete sensory block without need for general anesthesia, significant decrease in the post-operative VAS and significant increase time of first analgesic requirement as compared to the ACB group. Result and Conclusion: The present study demonstrates that blockade of lumber plexus by psoas compartment block is more effective in complete sensory block without general anesthesia supplementation in addition to decrease post-operative analgesic requirement than adductor canal block. PMID:27212766
Jeon, Younghoon; Kim, Saeyoung
Abstract Rationale: The great auricular nerve can be damaged by the neck surgery, tumor, and long-time pressure on the neck. But, great auricular neuralgia is very rare condition. It was managed by several medication and landmark-based great auricular nerve block with poor prognosis. Patient concerns: A 25-year-old man presented with a pain in the left lateral neck and auricle. Diagnosis: He was diagnosed with great auricular neuralgia. Interventions: His pain was not reduced by medication. Therefore, the great auricular nerve block with local anesthetics and steroid was performed under ultrasound guidance. Outcomes: Ultrasound guided great auricular nerve block alleviated great auricular neuralgia. Lessons: This medication-resistant great auricular neuralgia was treated by the ultrasound guided great auricular nerve block with local anesthetic agent and steroid. Therefore, great auricular nerve block can be a good treatment option of medication resistant great auricular neuralgia. PMID:28328811
Lang, I M; Medda, B K; Jadcherla, S; Shaker, R
The aim of this study was to determine the role of the superior laryngeal nerve (SLN) in the following esophageal reflexes: esophago-upper esophageal sphincter (UES) contractile reflex (EUCR), esophago-lower esophageal sphincter (LES) relaxation reflex (ELIR), secondary peristalsis, pharyngeal swallowing, and belch. Cats (N = 43) were decerebrated and instrumented to record EMG of the cricopharyngeus, thyrohyoideus, geniohyoideus, and cricothyroideus; esophageal pressure; and motility of LES. Reflexes were activated by stimulation of the esophagus via slow balloon or rapid air distension at 1 to 16 cm distal to the UES. Slow balloon distension consistently activated EUCR and ELIR from all areas of the esophagus, but the distal esophagus was more sensitive than the proximal esophagus. Transection of SLN or proximal recurrent laryngeal nerves (RLN) blocked EUCR and ELIR generated from the cervical esophagus. Distal RLN transection blocked EUCR from the distal cervical esophagus. Slow distension of all areas of the esophagus except the most proximal few centimeters activated secondary peristalsis, and SLN transection had no effect on secondary peristalsis. Slow distension of all areas of the esophagus inconsistently activated pharyngeal swallows, and SLN transection blocked generation of pharyngeal swallows from all levels of the esophagus. Slow distension of the esophagus inconsistently activated belching, but rapid air distension consistently activated belching from all areas of the esophagus. SLN transection did not block initiation of belch but blocked one aspect of belch, i.e., inhibition of cricopharyngeus EMG. Vagotomy blocked all aspects of belch generated from all areas of esophagus and blocked all responses of all reflexes not blocked by SLN or RLN transection. In conclusion, the SLN mediates all aspects of the pharyngeal swallow, no portion of the secondary peristalsis, and the EUCR and ELIR generated from the proximal esophagus. Considering that SLN is not
Medda, B. K.; Jadcherla, S.; Shaker, R.
The aim of this study was to determine the role of the superior laryngeal nerve (SLN) in the following esophageal reflexes: esophago-upper esophageal sphincter (UES) contractile reflex (EUCR), esophago-lower esophageal sphincter (LES) relaxation reflex (ELIR), secondary peristalsis, pharyngeal swallowing, and belch. Cats (N = 43) were decerebrated and instrumented to record EMG of the cricopharyngeus, thyrohyoideus, geniohyoideus, and cricothyroideus; esophageal pressure; and motility of LES. Reflexes were activated by stimulation of the esophagus via slow balloon or rapid air distension at 1 to 16 cm distal to the UES. Slow balloon distension consistently activated EUCR and ELIR from all areas of the esophagus, but the distal esophagus was more sensitive than the proximal esophagus. Transection of SLN or proximal recurrent laryngeal nerves (RLN) blocked EUCR and ELIR generated from the cervical esophagus. Distal RLN transection blocked EUCR from the distal cervical esophagus. Slow distension of all areas of the esophagus except the most proximal few centimeters activated secondary peristalsis, and SLN transection had no effect on secondary peristalsis. Slow distension of all areas of the esophagus inconsistently activated pharyngeal swallows, and SLN transection blocked generation of pharyngeal swallows from all levels of the esophagus. Slow distension of the esophagus inconsistently activated belching, but rapid air distension consistently activated belching from all areas of the esophagus. SLN transection did not block initiation of belch but blocked one aspect of belch, i.e., inhibition of cricopharyngeus EMG. Vagotomy blocked all aspects of belch generated from all areas of esophagus and blocked all responses of all reflexes not blocked by SLN or RLN transection. In conclusion, the SLN mediates all aspects of the pharyngeal swallow, no portion of the secondary peristalsis, and the EUCR and ELIR generated from the proximal esophagus. Considering that SLN is not
Volpato, Maria Cristina; Ranali, José; Ramacciato, Juliana Cama; de Oliveira, Patrícia Cristine; Ambrosano, Glaúcia Maria Bovi; Groppo, Francisco Carlos
The purpose of this study was to compare the anesthetic efficacy of 2 bupivacaine solutions. Twenty-two volunteers randomly received in a crossover, double-blinded manner 2 inferior alveolar nerve blocks with 1.8 mL of racemic bupivacaine and a mixture of 75% levobupivacaine and 25% dextrobupivacaine, both 0.5% and with 1 : 200,000 epinephrine. Before and after the injection, the first mandibular pre-molar was evaluated every 2 minutes until no response to the maximal output (80 reading) of the pulp tester and then again every 20 minutes. Data were analyzed using the Wilcoxon paired test and the paired t test. No differences were found between the solutions for onset and duration of pulpal anesthesia and duration of soft tissue anesthesia (P > .05). It was concluded that the solutions have similar anesthetic efficacy. PMID:16596912
Knight, Joshua B.; Schott, Nicholas J.; Kentor, Michael L.; Williams, Brian A.
Purpose of Review Outline the analgesic role of perineural adjuvants for local anesthetic nerve block injections, and evaluate current knowledge regarding whether adjuvants modulate the neurocytologic properties of local anesthetics. Recent Findings Perineural adjuvant medications such as dexmedetomidine, clonidine, buprenorphine, dexamethasone, and midazolam play unique analgesic roles. The dosing of these medications to prevent neurotoxicity is characterized in various cellular and in vivo models. Much of this mitigation may be via reducing the dose of local anesthetic used while achieving equal or superior analgesia. Dose-concentration animal models have shown no evidence of deleterious effects. Clinical observations regarding blocks with combined bupivacaine-clonidine-buprenorphine-dexamethasone have shown beneficial effects on block duration and rebound pain without long-term evidence of neurotoxicity. In vitro and in vivo studies of perineural clonidine and dexmedetomidine show attenuation of perineural inflammatory responses generated by local anesthetics. Summary Dexmedetomidine added as a peripheral nerve blockade adjuvant improves block duration without neurotoxic properties. The combined adjuvants clonidine, buprenorphine, and dexamethasone do not appear to alter local anesthetic neurotoxicity. Midazolam significantly increases local anesthetic neurotoxicity in vitro, but when combined with clonidine-buprenorphine-dexamethasone (sans local anesthetic) produces no in vitro or in vivo neurotoxicity. Further larger-species animal testing and human trials will be required to reinforce the clinical applicability of these findings. PMID:26207854
Silverman, Eric R.; Vydyanathan, Amaresh; Gritsenko, Karina; Shaparin, Naum; Singh, Nair; Downie, Sherry A.
Background. A recently described selective tibial nerve block at the popliteal crease presents a viable alternative to sciatic nerve block for patients undergoing total knee arthroplasty. In this two-part investigation, we describe the effects of a tibial nerve block at the popliteal crease. Methods. In embalmed cadavers, after the ultrasound-guided dye injection the dissection revealed proximal spread of dye within the paraneural sheath. Consequentially, in the clinical study twenty patients scheduled for total knee arthroplasty received the ultrasound-guided selective tibial nerve block at the popliteal crease, which also resulted in proximal spread of local anesthetic. A sensorimotor exam was performed to monitor the effect on the peroneal nerve. Results. In the cadaver study, dye was observed to spread proximal in the paraneural sheath to reach the sciatic nerve. In the clinical observational study, local anesthetic was observed to spread a mean of 4.7 + 1.9 (SD) cm proximal to popliteal crease. A negative correlation was found between the excess spread of local anesthetic and bifurcation distance. Conclusions. There is significant proximal spread of local anesthetic following tibial nerve block at the popliteal crease with possibility of the undesirable motor blocks of the peroneal nerve. PMID:28260964
Mesgarzadeh, Ali Hossein; Afsari, Hosein; Pourkhamne, Sohrab; Shahamfar, Mohamadreza
Background and aims. Postoperative pain control is extremely important for both patients and surgeons; in this context, long-acting local anesthesia can play an important role after open reduction of maxillofacial fractures. The purpose of this study was to evaluate the effect of bilateral mental nerve block with bupivacaine on postoperative pain control in mandibular symphyseal fractures. Materials and methods. Fifty patients with pure mandibular symphyseal fractures were studied in two control and study groups. In contrast to the control group, the study group received bilateral mental nerve block with bupivacaine postoperatively. Patients were examined in relation to pain severity and opioid analgesic drug need sequences. Results. The study group needed significantly less opioid than the control group (P<0.01, U=141). The control and study groups were different in first opioid administration time. The control and study groups received first opioid dose in 0-2 and 2-4 hours, respectively. Conclusion. Bilateral mental nerve blocks with bupivacaine can reduce opioid analgesic need and it has a positive effect on postoperative pain control in mandibular symphyseal fractures. PMID:25346837
Luyet, C.; Schüpfer, G.; Wipfli, M.; Greif, R.; Luginbühl, M.; Eichenberger, U.
Little is known about the learning of the skills needed to perform ultrasound- or nerve stimulator-guided peripheral nerve blocks. The aim of this study was to compare the learning curves of residents trained in ultrasound guidance versus residents trained in nerve stimulation for axillary brachial plexus block. Ten residents with no previous experience with using ultrasound received ultrasound training and another ten residents with no previous experience with using nerve stimulation received nerve stimulation training. The novices' learning curves were generated by retrospective data analysis out of our electronic anaesthesia database. Individual success rates were pooled, and the institutional learning curve was calculated using a bootstrapping technique in combination with a Monte Carlo simulation procedure. The skills required to perform successful ultrasound-guided axillary brachial plexus block can be learnt faster and lead to a higher final success rate compared to nerve stimulator-guided axillary brachial plexus block. PMID:21318138
Yu, Bin; He, Miao; Cai, Guang-Yu; Zou, Tian-Xiao; Zhang, Na
Abstract Background: Continuous femoral nerve block and fascia iliaca compartment block are 2 traditional anesthesia methods in orthopedic surgeries, but it is controversial which method is better. The objective of this study was to compare the practicality, efficacy, and complications of the 2 modalities in hip replacement surgery in the elderly and to assess the utility of a novel cannula-over-needle set. Methods: In this prospective, randomized controlled clinical investigation, 60 elderly patients undergoing hip replacement were randomly assigned to receive either continuous femoral nerve block or continuous fascia iliaca compartment block. After ultrasound-guided nerve block, all patients received general anesthesia for surgery and postoperative analgesia through an indwelling cannula. Single-factor analysis of variance was used to compare the outcome variables between the 2 groups. Results: There was a significant difference between the 2 groups in the mean visual analog scale scores (at rest) at 6 hours after surgery: 1.0 ± 1.3 in the femoral nerve block group vs 0.5 ± 0.8 in the fascia iliaca compartment block group (P < 0.05). The femoral nerve block group had better postoperative analgesia on the medial aspect of the thigh, whereas the fascia iliaca compartment block group had better analgesia on the lateral aspect of the thigh. There were no other significant differences between the groups. Conclusions: Both ultrasound-guided continuous femoral nerve block and fascia iliaca compartment block with the novel cannula-over-needle provide effective anesthesia and postoperative analgesia for elderly hip replacement patients. PMID:27759633
Joe, Han Bum; Choo, Ho Sik; Yoon, Ji Sang; Oh, Sang Eon; Cho, Jae Ho; Park, Young Uk
Abstract Background: A femoral nerve block (FNB) in combination with a sciatic nerve block (SNB) is commonly used for anesthesia and analgesia in patients undergoing hindfoot and ankle surgery. The effects of FNB on motor function, related fall risk, and rehabilitation are controversial. An adductor canal block (ACB) potentially spares motor fibers in the femoral nerve, but the comparative effect on hindfoot and ankle surgeries between the 2 approaches is not yet well defined. We hypothesized that compared to FNB, ACB would cause less weakness in the quadriceps and produce similar pain scores during and after the operation. Methods: Sixty patients scheduled for hindfoot and ankle surgeries (arthroscopy, Achilles tendon surgery, or medial ankle surgery) were stratified randomized for each surgery to receive an FNB (FNB group) or an ACB (ACB group) combined with an SNB. The primary outcome was the visual analog scale (VAS) pain score at each stage. Secondary outcomes included quadriceps strength, time profiles (duration of the block procedure, time to full anesthesia and time to full recovery), patients’ analgesic requirements, satisfaction, and complications related to peripheral nerve blocks such as falls, neurologic symptoms, and local anesthetic systemic toxicity were evaluated. The primary outcome was tested for the noninferiority of ACB to FNB, and the other outcomes were tested for the superiority of each variable between the groups. Results: A total of 31 patients received an ACB and 29 received an FNB. The VAS pain scores of the ACB group were not inferior during and after the operation compared to those of the FNB group. At 30 minutes and 2 hours after anesthesia, patients who received an ACB had significantly higher average dynamometer readings than those who received a FNB (34.2 ± 20.4 and 30.4 ± 23.7 vs 1.7 ± 3.7 and 2.3 ± 7.4, respectively), and the results were similar at 24 and 48 hours after anesthesia. There were no differences
Vrabec, Tina; Bhadra, Niloy; Wainright, Jesse; Bhadra, Narendra; Franke, Manfred; Kilgore, Kevin
Direct current (DC) can briefly produce a reversible nerve conduction block in acute experiments. However, irreversible reactions at the electrode–tissue interface have prevented its use in both acute and chronic settings. A high capacitance material (platinum black) using a charge-balanced waveform was evaluated to determine whether brief DC block (13 s) could be achieved repeatedly (>100 cycles) without causing acute irreversible reduction in nerve conduction. Electrochemical techniques were used to characterize the electrodes to determine appropriate waveform parameters. In vivo experiments on DC motor conduction block of the rat sciatic nerve were performed to characterize the acute neural response to this novel nerve block system. Complete nerve motor conduction block of the rat sciatic nerve was possible in all experiments, with the block threshold ranging from −0.15 to −3.0 mA. DC pulses were applied for 100 cycles with no nerve conduction reduction in four of the six platinum black electrodes tested. However, two of the six electrodes exhibited irreversible conduction degradation despite charge delivery that was within the initial Q (capacitance) value of the electrode. Degradation of material properties occurred in all experiments, pointing to a possible cause of the reduction in nerve conduction in some platinum black experiments. PMID:26358242
Vrabec, Tina; Bhadra, Niloy; Wainright, Jesse; Bhadra, Narendra; Franke, Manfred; Kilgore, Kevin
Direct current (DC) can briefly produce a reversible nerve conduction block in acute experiments. However, irreversible reactions at the electrode-tissue interface have prevented its use in both acute and chronic settings. A high capacitance material (platinum black) using a charge-balanced waveform was evaluated to determine whether brief DC block (13 s) could be achieved repeatedly (>100 cycles) without causing acute irreversible reduction in nerve conduction. Electrochemical techniques were used to characterize the electrodes to determine appropriate waveform parameters. In vivo experiments on DC motor conduction block of the rat sciatic nerve were performed to characterize the acute neural response to this novel nerve block system. Complete nerve motor conduction block of the rat sciatic nerve was possible in all experiments, with the block threshold ranging from -0.15 to -3.0 mA. DC pulses were applied for 100 cycles with no nerve conduction reduction in four of the six platinum black electrodes tested. However, two of the six electrodes exhibited irreversible conduction degradation despite charge delivery that was within the initial Q (capacitance) value of the electrode. Degradation of material properties occurred in all experiments, pointing to a possible cause of the reduction in nerve conduction in some platinum black experiments .
Parris, David; Fischbein, Nancy; Mackey, Sean; Carroll, Ian
Background Inguinal hernia repair is associated with a high incidence of chronic postsurgical pain. This pain may be caused by injury to the iliohypogastric, ilioinguinal, or genitofemoral nerves. It is often difficult to identify the specific source of the pain, in part, because these nerves are derived from overlapping nerve roots and closely colocalize in the area of surgery. It is therefore technically difficult to selectively block these nerves individually proximal to the site of surgical injury. In particular, the genitofemoral nerve is retroperitoneal before entering the inguinal canal, a position that puts anterior approaches to the proximal nerve at risk of transgressing into the peritoneum. We report a computed tomography (CT)-guided transpsoas technique to selectively block the genitofemoral nerve for both diagnostic and therapeutic purposes while avoiding injury to the nearby ureter and intestines. Case A 39-year-old woman with chronic lancinating right groin pain after inguinal hernia repair underwent multiple pharmacologic interventions and invasive procedures without relief. Using CT and Stimuplex nerve stimulator guidance, the genitofemoral nerve was localized on the anterior surface of the psoas muscle and a diagnostic block with local anesthetic block was performed. The patient had immediate relief of her symptoms for 36 hours, confirming the diagnosis of genitofemoral neuralgia. She subsequently underwent CT-guided radiofrequency and phenol ablation of the genitofemoral nerve but has not achieved long-term analgesia. Conclusion CT-guided transpsoas genitofemoral nerve block is a viable option for safely and selectively blocking the genitofemoral nerve for diagnostic or therapeutic purposes proximal to injury caused by inguinal surgery. PMID:20546515
Dufour, Eric; Cymerman, Alexandre; Nourry, Gérard; Balland, Nicolas; Couturier, Christian; Liu, Ngai; Dreyfus, Jean-François; Fischler, Marc
Nerve stimulation is an effective technique for peripheral nerve blockade. However, the local anesthetic (LA) distribution pattern obtained with this blind approach is unknown and may explain its clinical effects. One hundred patients received a median nerve block at the elbow using a nerve stimulator approach. After correct needle placement defined by a minimal stimulating current < or = 0.5 mA (2 Hz, 0.1 millisecond), 6 mL lidocaine 1.5%with epinephrine 1:200,000 was injected. A linear 5- to 13-MHz probe (12L-RS) was used to assess a cross-section area of median nerve, which was calculated by 3 consecutive measurements before and after injection, and LA circumferential spread around the nerve during static and longitudinal examination. Intraneural injection defined as an increase in nerve area was detected using an iterative method for outlier detection. Results of sensory tests (cold and light touch) on 3 nerve territories and of motor blockade were compared with the imaging aspects. We performed clinical neurological examination at 3 days and 1 month after block. Nerve swelling, considered significant when an increase in cross-sectional area was > or = 75%, was observed in 43 patients. Nerve swelling associated with a circumferential LA spread image, present in 37 patients, was associated with a sensory success rate of 86%. The success rate was 34% for 32 patients in whom none of these signs was visualized. A circumferential spread around a nonswollen nerve, present in 25 patients, was followed by a sensory success rate of 76% within the 30-minute evaluation period. No major early neurological complications were observed. Nerve stimulation does not prevent intraneural injection. In the absence of intraneural injection, the presence of circumferential LA spread image seemed predictive of successful sensory block in almost 75% of the cases within the 30-minute evaluation period.
Stav, Anatoli; Reytman, Leonid; Sevi, Roger; Stav, Michael Yohay; Powell, Devorah; Dor, Yanai; Dudkiewicz, Mickey; Bayadse, Fuaz; Sternberg, Ahud; Soudry, Michael
Background The PROSPECT (Procedure-Specific Postoperative Pain Management) Group recommended a single injection femoral nerve block in 2008 as a guideline for analgesia after total knee arthroplasty. Other authors have recommended the addition of sciatic and obturator nerve blocks. The lateral femoral cutaneous nerve is also involved in pain syndrome following total knee arthroplasty. We hypothesized that preoperative blocking of all four nerves would offer superior analgesia to femoral nerve block alone. Methods This is a prospective, randomized, controlled, and observer-blinded clinical study. A total of 107 patients were randomly assigned to one of three groups: a femoral nerve block group, a multiple nerve block group, and a control group. All patients were treated postoperatively using patient-controlled intravenous analgesia with morphine. Pain intensity at rest, during flexion and extension, and morphine consumption were compared between groups over three days. Results A total of 90 patients completed the study protocol. Patients who received multiple nerve blocks experienced superior analgesia and had reduced morphine consumption during the postoperative period compared to the other two groups. Pain intensity during flexion was significantly lower in the “blocks” groups versus the control group. Morphine consumption was significantly higher in the control group. Conclusions Pain relief after total knee arthroplasty immediately after surgery and on the first postoperative day was significantly superior in patients who received multiple blocks preoperatively, with morphine consumption significantly lower during this period. A preoperative femoral nerve block alone produced partial and insufficient analgesia immediately after surgery and on the first postoperative day. (Clinical trial registration number (NIH): NCT01303120) PMID:28178436
Moore, Paul A; Cuddy, Michael A; Cooke, Matthew R; Sokolowski, Chester J
and Overview. The provision of mandibular anesthesia traditionally has relied on nerve block anesthetic techniques such as the Halsted, the Gow-Gates and the Akinosi-Vazirani methods. The authors present two alternative techniques to provide local anesthesia in mandibular teeth: the periodontal ligament (PDL) injection and the intraosseous (IO) injection. The authors also present indications for and complications associated with these techniques. The PDL injection and the IO injection are effective anesthetic techniques for managing nerve block failures and for providing localized anesthesia in the mandible. Dentists may find these techniques to be useful alternatives to nerve block anesthesia.
Gadsden, Jeff; Latmore, Malikah; Levine, D Matt; Robinson, Allegra
High opening injection pressures (OIPs) have been shown to predict sustained needle tip contact with the roots of the brachial plexus. Such roots have a uniquely high ratio of fascicular versus connective tissue. It is unknown if this relationship is preserved during multifascicular nerve blockade. We hypothesized that OIP can predict needle-nerve contact during femoral nerve block, as well as detect needle contact with the fascia iliaca. Twenty adults scheduled for femoral block were recruited. Using ultrasound, a 22-gauge needle was sequentially placed in 4 locations: indenting the fascia iliaca, advanced through the fascia iliaca while lateral to the nerve, slightly indenting the femoral nerve, and withdrawn from the nerve 1 mm. At each location, the OIP required to initiate an injection of 1 mL D5W (5% dextrose in water) at 10 mL/min was recorded. Blinded investigators performed evaluations and aborted injections when an OIP of 15 psi was reached. Opening injection pressure was 15 psi or greater for 90% and 100% of cases when the needle indented the femoral nerve and fascia iliaca, respectively. Opening injection pressure was less than 15 psi for all 20 patients when the needle was withdrawn 1 mm from the nerve as well as at the subfascial position (McNemar χ2 P < 0.001). Opening injection pressure greater than 15 psi was associated with a block needle tip position slightly indenting the epineurium of the femoral nerve (90%) and the fascia iliaca (100%). Needle tip positions not indenting these structures were associated with OIP of less than 15 psi (100%).
Redborg, Kirsten E; Antonakakis, John G; Beach, Michael L; Chinn, Christopher D; Sites, Brian D
The tibial nerve provides the majority of sensation to the foot. Although multiple techniques have been described, there exists little evidence-based medicine evaluating different techniques for blocking the tibial nerve at the ankle. We hypothesized that an ultrasound (US)-guided tibial nerve block at the ankle would prove more successful than a conventional approach based on surface landmarks. Eighteen healthy volunteers were prospectively randomized into this controlled and blinded study. Each subject was placed prone, and one ankle was randomly assigned to receive either an US-guided tibial nerve block (group US) or a traditional landmark-based tibial nerve block (group LM). The subject's other ankle then received the alternate approach. All blocks were performed with 5 mL of 3% chloroprocaine. We evaluated sensory and motor blocks. A successful block was defined as complete loss of sensation to both ice and pinprick at 5 cutaneous sites. Secondary outcome variables included performance times, number of needle passes, participant satisfaction, and presence of any complications. At 30 mins, the block was complete in 72% of participants in group US as compared with 22% in group LM. At all times, the proportion of complete blocks was higher in group US. Ultrasound-guided blocks took longer on average to perform than traditional blocks (159 vs 79 secs; P < 0.001). There were more needle redirects in group US, with 8 subjects requiring 3 or more redirects versus none in group LM. Subjects preferred the US block 78% of the time (95% confidence interval, 52%-95%). In healthy volunteers, US guidance results in a more successful tibial nerve block at the ankle than does a traditional approach using surface landmarks.
Chatrath, Veena; Sharan, Radhe; Jain, Payal; Bala, Anju; Ranjana; Sudha
Aims of Study: To evaluate the efficacy, hemodynamic changes, and patient comfort during awake fiberoptic intubation done under combined regional blocks. Materials and Methods: In the present observational study, 50 patients of American Society of Anesthesiologists ( ASA) Grade I–II, Mallampati Grade I–IV were given nerve blocks - bilateral glossopharyngeal nerve block, bilateral superior laryngeal nerve block, and recurrent laryngeal nerve block before awake fiberoptic intubation using 2% lidocaine. Results: Procedure was associated with minimal increases in hemodynamic parameters during the procedure and until 3 min after it. Most of the intubations were being carried out within 3 min. Patient comfort was satisfactory with 90% of patients having favorable grades. Discussion: The most common cause of mortality and serious morbidity due to anesthesia is from airway problems. One-third of all anesthetic deaths are due to failure to intubate and ventilate. Awake flexible fiberoptic intubation under local anesthesia is now an accepted technique for managing such situations. In awake patient's anatomy, muscle tone, airway protection, and ventilation are preserved, but it is essential to sufficiently anesthetize the upper airway before the performance of awake fiberoptic bronchoscope-guided intubation to ensure patient comfort and cooperation for which in our study we used the nerve block technique. Conclusion: A properly performed technique of awake fiberoptic intubation done under combined regional nerve blocks provides good intubating conditions, patient comfort and safety and results in minimal hemodynamic changes. PMID:27212757
Orebaugh, Steven L; Kentor, Michael L; Williams, Brian A
We previously published a retrospective review of complications related to peripheral nerve blocks performed by supervised trainees, from our quality assurance and billing data, guided by either ultrasound, with nerve stimulator confirmation, or landmark-based nerve stimulator techniques. This report updates our results, for the period from May 2008 through December 2011, representing ongoing transition to near-complete combined ultrasound/nerve stimulator guidance in a block-oriented, outpatient orthopedic anesthesia practice. We queried our deidentified departmental quality improvement electronic database for adverse outcomes associated with peripheral nerve blocks. Billing records were also deidentified and used to provide the denominator of total number of blocks using each technique of neurolocation. The types of blocks considered in this analysis were interscalene, axillary, femoral, sciatic, and popliteal-sciatic blocks. Nerve block complications based on each type of guidance were then compared for the entire recent 30-month time period, as well as for the 6-year period of this report. There were 9062 blocks performed by ultrasound/nerve stimulator, and 5436 by nerve stimulator alone over the entire 72-month period. Nerve injuries lasting longer than 1 year were rare, but similar in frequency with both nerve guidance techniques. The incidence of local anesthetic systemic toxicity was found to be higher with landmark-nerve stimulator technique than with use of ultrasound-guided nerve blocks (6/5436 vs 0/9069, P = 0.0061). We report a large series of combined ultrasound/nerve stimulator nerve blocks by supervised trainees without major local anesthetic systemic toxicity. While lacking the compelling evidence of randomized controlled trials, this observational database nonetheless allows increased confidence in the safety of using combined ultrasound/nerve stimulator in the setting of anesthesiologists-in-training.
Moddel, G.; Best, B.; Ashby, P.
The differential nerve block produced by ischaemia has been used in an attempt to identify the afferent nerve fibres responsible for vibratory inhibition of the monosynaptic reflex in man. It is concluded that the inhibition arises mainly from receptors in the lower leg and is carried by myelinated afferent fibres larger than A-delta. PMID:599354
Veneziano, Giorgio C; Rao, Vidya K; Orebaugh, Steven L
Nerve stimulation may occur despite the presence of a fascial barrier between the needle tip and the nerve, which may prevent appropriate flow or distribution of local anesthetic solution. During an axillary nerve block, ultrasound (US) guidance was used to identify the median nerve. Insertion of a needle with US and nerve stimulator guidance resulted in the appearance of the needle tip in contact with the nerve. However, as local anesthetic injection was begun, it was clear that the injectate was accumulating superficial to the investing fascia of the neurovascular bundle. No injectate was seen below the fascia. With US guidance, the needle was repositioned at a greater depth. Repeat injection of local anesthetic clearly flowed around the nerve. Copyright Â© 2012 Elsevier Inc. All rights reserved.
Kim, Jeong Eun; Kim, Eun Ju; Min, Byung Woo; Ban, Jong Suk; Lee, Ji Hyang
Meralgia paresthetica is a rarely encountered sensory mononeuropathy characterized by paresthesia, pain or sensory impairment along the distribution of the lateral femoral cutaneous nerve (LFCN) caused by entrapment or compression of the nerve as it crossed the anterior superior iliac spine and runs beneath the inguinal ligament. There is great variability regarding the area where the nerve pierces the inguinal ligament, which makes it difficult to perform blind anesthetic blocks. Ultrasound has developed into a powerful tool for the visualization of peripheral nerves including very small nerves such as accessory and sural nerves. The LFCN can be located successfully, and local anesthetic solution distribution around the nerve can be observed with ultrasound guidance. Our successfully performed ultrasound-guided blockade of the LFCN in meralgia paresthetica suggests that this technique is a safe way to increase the success rate. PMID:21716611
Kim, Jeong Eun; Lee, Sang Gon; Kim, Eun Ju; Min, Byung Woo; Ban, Jong Suk; Lee, Ji Hyang
Meralgia paresthetica is a rarely encountered sensory mononeuropathy characterized by paresthesia, pain or sensory impairment along the distribution of the lateral femoral cutaneous nerve (LFCN) caused by entrapment or compression of the nerve as it crossed the anterior superior iliac spine and runs beneath the inguinal ligament. There is great variability regarding the area where the nerve pierces the inguinal ligament, which makes it difficult to perform blind anesthetic blocks. Ultrasound has developed into a powerful tool for the visualization of peripheral nerves including very small nerves such as accessory and sural nerves. The LFCN can be located successfully, and local anesthetic solution distribution around the nerve can be observed with ultrasound guidance. Our successfully performed ultrasound-guided blockade of the LFCN in meralgia paresthetica suggests that this technique is a safe way to increase the success rate.
Shanahan, E; Smith, M; Wetherall, M; Lott, C; Slavotinek, J; FitzGerald, O; Ahern, M
Background: Suprascapular nerve block is a safe and effective treatment for chronic shoulder pain in arthritis, which can be performed either by direct imaging (CT guided) or in the clinic using anatomical landmarks to determine needle placement. Objective: To compare a CT guided versus an anatomical landmark approach in a randomised, single blind trial examining the efficacy of suprascapular nerve block for shoulder pain in patients with degenerative joint/rotator cuff disease. Methods: 67 patients with chronic shoulder pain from degenerative disease participated in the trial. 77 shoulders were randomised. The group randomised to receive the block through the anatomical landmark approach received a single suprascapular nerve block. Those in the CT guided group received an injection of methylprednisolone acetate and a smaller volume of bupivacaine around the suprascapular nerve. The patients were followed up for 12 weeks by a "blinded" observer and reviewed at weeks 1, 4, and 12 after the injection. Results: Significant improvements were seen in all pain scores and disability in the shoulders receiving both types of nerve block, with no significant differences in the improvement in pain and disability between the two approaches at any time. Improvements in pain and disability scores were clinically and statistically significant. No significant adverse effects occurred in either group. Patient satisfaction scores for pain relief using either approach were high. Conclusion: The CT guided control and landmark approaches to performing suprascapular nerve blocks result in similar significant and prolonged pain and disability reductions; both approaches are safe. PMID:15308514
Kolawole, Israel K; Adesina, Michael D; Olaoye, Iyiade O
Regional anesthesia is recognized as an alternative to general anesthesia for modern breast cancer surgery. Various techniques of block have been described. Each has its unique problems. Regional anesthesia was chosen for simple mastectomy in two patients with advanced breast malignancy, due to compromised pulmonary status resulting from widespread malignant infiltration of both lungs. We used intercostal nerves block. The block was supplemented with an infraclavicular infiltration to interrupt the branches of the superficial cervical plexus that provide sensation to the upper chest wall and subcutaneous infiltration in the midline to block the nerve supply from the contralateral side. Anesthesia was generally effective and the operations were uneventful. Both patients and surgeons expressed satisfaction. We conclude that where patients have significant comorbidities that make general anesthesia undesirable, the use of intercostal nerves block remains a safe and reliable anesthetic option that allows the patient access to surgery for simple mastectomy.
Kolawole, Israel K.; Adesina, Michael D.; Olaoye, Iyiade O.
Regional anesthesia is recognized as an alternative to general anesthesia for modern breast cancer surgery. Various techniques of block have been described. Each has its unique problems. Regional anesthesia was chosen for simple mastectomy in two patients with advanced breast malignancy, due to compromised pulmonary status resulting from widespread malignant infiltration of both lungs. We used intercostal nerves block. The block was supplemented with an infraclavicular infiltration to interrupt the branches of the superficial cervical plexus that provide sensation to the upper chest wall and subcutaneous infiltration in the midline to block the nerve supply from the contralateral side. Anesthesia was generally effective and the operations were uneventful. Both patients and surgeons expressed satisfaction. We conclude that where patients have significant comorbidities that make general anesthesia undesirable, the use of intercostal nerves block remains a safe and reliable anesthetic option that allows the patient access to surgery for simple mastectomy. Images Figure 1 Figure 2 Figure 3 PMID:16573313
Bhadra, Narendra; Foldes, Emily; Vrabec, Tina; Kilgore, Kevin L; Bhadra, Niloy
Application of Kilohertz Frequency Alternating Current (KHFAC) waveforms can result in nerve conduction block that is induced in less than a second. Conduction recovers within seconds when KHFAC is applied for about 5 - 10 minutes. This study investigated the effect of repeated and prolonged application of KHFAC on rat Sciatic nerve with bipolar platinum electrodes. Approach: Varying durations of KHFAC at signal amplitudes for conduction block with intervals of no stimulus were studied. Nerve conduction was monitored by recording peak Gastrocnemius muscle force utilizing stimulation electrodes proximal (PS) and distal (DS) to a blocking electrode. The PS signal traveled through the block zone on the nerve, while the DS went directly to the motor end-plate junction. The PS/DS force ratio provided a measure of conduction patency of the nerve in the block zone. Main Results: Conduction recovery times were found to be significantly affected by the cumulative duration of KHFAC application. Peak stimulated muscle force returned to pre-block levels immediately after cessation of KHFAC delivery when it was applied for less than about 15 minutes. They fell significantly but recovered to near pre-block levels for cumulative stimulus between 50 +/- 20 minutes, for the tested On / Off times and frequencies. Conduction recovered in two phases, an initial fast one (60 -80% recovery), followed by a slower phase. No permanent conduction block was seen at the end of the observation period during any experiment. Significance: This Carry-over Block Effect (COBE) may be exploited to provide continuous conduction block in peripheral nerves without continuous application of KHFAC. . © 2017 IOP Publishing Ltd.
Ohtori, Seiji; Yamashita, Masaomi; Inoue, Gen; Yamauchi, Kazuyo; Suzuki, Munetaka; Orita, Sumihisa; Eguchi, Yawara; Ochiai, Nobuyasu; Kishida, Shunji; Takaso, Masashi; Takahashi, Kazuhisa
Elderly patients with osteoporosis sometimes experience lumbar vertebral fracture and may feel diffuse nonlocalized pain in the back, the lateral portion of the trunk, and the area surrounding the iliac crest. The pattern of sensory innervation of vertebral bodies remains unclear. Some sensory nerves from the L2 and L5 vertebral bodies may enter the paravertebral sympathetic trunks and reach the L2 dorsal root ganglion. Our randomized controlled study was to clarify the effect of L2 spinal nerve block on low back pain originating from acute osteoporotic lumbar vertebral fracture. Patients with low back pain originating from acute L3 or L4 osteoporotic vertebral fractures received a spinal nerve root block (L2 block group, n = 30) or subcutaneous injection (control, n = 30). Both groups received 1.5 mL of 1% lidocaine. The visual analog scale score, Roland Morris Disability Questionnaire, and Short Form questionnaire were examined before and after treatment. In both groups, spinal nerve blocks were significantly effective in alleviating low back pain (P < .05). One hour, 1 week, and 2 weeks after treatment, the visual analog scale score improved more in the L2 block group than in the control group (P < .05). From 1 month to 4 months after treatment, there were no significant differences in the pain scores between groups (P > .05). We conclude that L2 spinal nerve block for acute L3 or L4 osteoporotic vertebral body fracture was effective for 2 weeks, but it had no long-term effects on pain and social function. L2 spinal nerve block treatment for L3 or L4 osteoporotic vertebral body fracture was effective. This results suggest that the L2 dorsal root ganglion may innervate the L3 and L4 vertebral bodies in humans. L2 spinal nerve block for lumbar osteoporotic vertebral fracture may be a useful strategy to treat acute low back pain.
Jung, Mi Jin; Byun, Ha Young; Lee, Chang Hee; Moon, Seung Won; Oh, Min-Kyun; Shin, Heesuk
Medial antebrachial cutaneous (MABC) nerve injury associated with iatrogenic causes has been rarely reported. Local anesthesia may be implicated in the etiology of such injury, but has not been reported. Two patients with numbness and painful paresthesia over the medial aspect of the unilateral forearm were referred for electrodiagnostic study, which revealed MABC nerve lesion in each case. The highly selective nature of the MABC nerve injuries strongly suggested that they were the result of direct nerve injury by an injection needle during previous brachial plexus block procedures. Electrodiagnostic studies can be helpful in evaluating cases of sensory disturbance after local anesthesia. To our knowledge, these are the first documented cases of isolated MABC nerve injury following ultrasound-guided axillary brachial plexus block.
Tighe, Patrick J.; Brennan, Meghan; Moser, M.; Boezaart, Andre P.; Bihorac, Azra
Introduction Although more than 30 million patients in the United States undergo ambulatory surgery each year, it remains unclear what percentage of these patients receive a perioperative nerve block. We reviewed data from the 2006 National Survey of Ambulatory Surgery (NSAS) to determine the demographic, socioeconomic, geographic, and clinical factors associated with the likelihood of nerve block placement for ambulatory orthopedic surgery. The primary outcome of interest was the association between primary method of payment and likelihood of nerve block placement. Additionally, we examined the association between type of surgical procedures, patient demographics, and hospital characteristics with the likelihood of receiving a nerve block. Methods This cross-sectional study reviewed 6,000 orthopedic anesthetics from the 2006 NSAS dataset, which accounted for over 3.9 million orthopedic anesthetics when weighted. The primary outcome of this study addressed the likelihood of receiving a nerve block for orthopedic ambulatory surgery according to the patient’s primary method of payment. Secondary endpoints included differences in demographics, surgical procedures, side effects, complications, recovery profile, anesthesia staffing model, and total perioperative charges in those with and without nerve block. Results Overall, 14.9% of anesthetics in this sample involved a peripheral nerve block. Length of time in postoperative recovery, total perioperative time, and total charges were less for those receiving nerve blocks. Patients were more likely to receive a nerve block if their procedures were performed in metropolitan service areas (OR 1.86, 95% CI 1.19-2.91, p=0.007) or freestanding surgical facilities (OR 2.27, 95% CI 1.74-2.96, p<0.0001), and if payment for their surgery was supported by government programs (OR 2.5, 95% CI 1.01-6.21, p=0.048) or private insurance (OR 2.62, 95% CI 1.12-6.13, p=0.03) versus self-pay or charity care. Conclusion For patients
Bali, Rishi Kumar; Nautiyal, Vijay P; Sharma, Praveen; Sharma, Rohit
The maxillary teeth are supplied by the anterior, middle and posterior superior alveolar nerves. The anterior and middle superior alveolar (AMSA) nerves exit the skull from the infra-orbital foramen, where they can be blocked for procedures on the maxillary anteriors and premolars. Sometimes, the middle superior alveolar nerve has a variant course and is not blocked by the conventional block technique. A new technique has been described for blocking the AMSA nerves, keeping in view the alternate pathway of the middle superior alveolar nerve. PMID:25756021
Nair, Gopakumar Sudhakaran; Soliman, Loran Mounir; Maheshwari, Kamal; Esa, Wael Ali Sakr
Introduction Continuous peripheral nerve block achieves good pain control. However, uncontrolled pain despite an effective block in the target areas of the nerve can be an early sign of ischemia. We report a case of iatrogenic injury to the axillary artery during shoulder surgery in a patient who had continuous supraclavicular block and demonstrate how vigilant monitoring helped the diagnosis and resulted in timely management of upper limb ischemia. Case Report A 58-year-old female underwent total revision surgery of her right shoulder under continuous supraclavicular block. Postoperatively, she complained of pain along the medial side of her forearm despite clinical evidence of nerve block. Continuous neurovascular monitoring and timely angiography confirmed axillary artery injury, and subsequent vascular repair saved the patient's limb. Conclusion Iatrogenic injuries to vessels or nerves sometimes occur during orthopedic surgical procedures. Regional anesthesia can mask and delay the onset of these symptoms. Postoperative monitoring and the ability to differentiate between the effects of local anesthetics and the body's response to ischemia are important for avoiding postoperative complications. This case report aims to improve awareness about the need for vigilant monitoring of the distal pulses after peripheral nerve blocks. PMID:23789016
Vizcarra-Román, M A; Bahena-Aponte, J A; Cruz-Jarquín, A; Vázquez-García, Ja C; Cárdenas-Lailson, L E
Postoperative pain after open cholecystectomy is associated with reduced respiratory function, longer recovery period before deambulation and oral food intake, and prolonged hospital stay. Intercostal nerve block provides satisfactory analgesia and ropivacaine is the most widely used local anesthetic agent in intercostal nerve block due to its excellent effectiveness, lower cardiovascular toxicity, and longer half-life. To evaluate intercostal nerve block effectiveness with ropivacaine in patients undergoing emergency open cholecystectomy under general anesthesia compared with conventional management. A controlled clinical trial was carried out on 50 patients undergoing open cholecystectomy, 25 patients without intercostal nerve block versus 25 patients with intercostal nerve block using ropivacaine at 0.5% combined with epinephrine. Intraoperative minimum alveolar concentration and inhalation anesthetic use were evaluated. Tramadol as rescue analgesic agent and pain were evaluated during immediate postoperative period by means of the Visual Analog Scale at 8, 16, and 24 hours. Mean inhalation anesthetic use was lower in the intercostal nerve block group with 13% vs 37% in the group without intercostal nerve block (p= 0.01). Rescue tramadol requirement was lower in the intercostal nerve block group than in the group without intercostal nerve block at 8 hours (8% vs 67%), 16 hours (0% vs 83%), and 24 hours (12% vs 79%) (p<0.0001). Visual Analog Scale for Pain results were similar in both groups. Intercostal nerve block reduces intraoperative inhalation anesthetic use, immediate postoperative pain, and tramadol intake as rescue analgesic agent in patients undergoing open cholecystectomy.
Haas, Daniel A
and Overview. The limited success rate of the standard inferior alveolar nerve block (IANB) has led to the development of alternative approaches for providing mandibular anesthesia. Two techniques, the Gow-Gates mandibular nerve block and the Akinosi-Vazirani closed-mouth mandibular nerve block, are reliable alternatives to the traditional IANB. The Gow-Gates technique requires the patient's mouth to be open wide, and the dentist aims to administer local anesthetic just anterior to the neck of the condyle in proximity to the mandibular branch of the trigeminal nerve after its exit from the foramen ovale. The Akinosi-Vazirani technique requires the patient's mouth to be closed, and the dentist aims to fill the pterygomandibular space with local anesthetic. Both techniques are indicated for any type of dentistry performed in the mandibular arch, but they are particularly advantageous when the patient has a history of standard IANB failure owing to anatomical variability or accessory innervation. Having the skill to perform these alternative anesthetic techniques increases dentists' ability to provide successful local anesthesia consistently for all procedures in mandibular teeth.
Tan, Ngukhoon; Agnew, Neil M; Scawn, Nigel D; Pennefather, Stephen H; Chester, Michael; Russell, Glenn N
Despite receiving thoracic epidural analgesia, severe ipsilateral shoulder pain is common in patients after thoracotomy. We recruited 44 patients into a double-blinded randomized placebo-controlled study to investigate whether suprascapular nerve block would treat postthoracotomy shoulder pain effectively. All patients received a standard anesthetic with a midthoracic epidural. Thirty patients who experienced shoulder pain within 2 h of surgery were randomly assigned to receive a suprascapular nerve block with either 10 mL of 0.5% bupivacaine or 10 mL of 0.9% saline. Shoulder pain was assessed before nerve blockade, at 30 min, and then hourly for 6 h after the block using a visual analog scale (VAS) and a 5-point verbal ranking score (VRS). The incidence of shoulder pain before nerve block was 78%. There was no significant decrease in either VAS or VRS in the Bupivacaine group. These results suggest that this pain is unlikely to originate in the shoulder and lead us to question the role of a somatic afferent in referred visceral pain. We conclude that suprascapular nerve block does not treat ipsilateral shoulder pain after thoracotomy in patients with an effective thoracic epidural. This randomized, double-blinded, placebo-controlled trial showed that suprascapular nerve block does not treat the severe ipsilateral shoulder pain that patients experience after thoracotomy. This has implications for established theories of referred pain and indicates that this pain is unlikely to originate in the shoulder.
Aravena, Pedro Christian; Valeria, Camila; Nuñez, Nicolás; Perez-Rojas, Francisco; Coronado, Cesar
The anesthetic block of the inferior alveolar nerve (IAN) is one of the most common techniques used in dental practice. The local complications are due to the failures on the anesthetic block or to anatomic variations in the tap site such as intravascular injection, skin ischemia and ocular problems. The aim of this article is to present a case and discuss the causes of itching and burning sensation, blanching, pain and face ischemia in the oral cavity during the IAN block. PMID:28182074
Joseph, Laveeta; Haeffele, Benjamin D; Butera, Robert J
The potential neurophysiological applications of high frequency AC stimulation (HFAC) in blocking conduction has led to a series of experimental and modeling studies analyzing the effect of HFAC conduction block on mixed nerves. However, many of these computational studies have been based on axon models that are perhaps not valid for the nerves under study. The isolated response of unmyelinated nerves to HFAC has also not been previously studied. In this study, 5-50 kHz sinusoidal HFAC stimulation waveforms were used to reversibly block conduction through the unmyelinated nerve fibers of Aplysia. Unlike myelinated nerves, the minimum HFAC amplitude for blocking conduction in these nerves showed a non-monotonic behavior with frequency. The Hodgkin-Huxley model did not accurately predict the experimentally observed trends but modifying the model to incorporate a frequency-dependent membrane capacitance resulted in a significant change in the high frequency response of the model while still preserving the standard characteristics of action potential propagation.
Albert, Thierry A; Yelnik, Alain; Bonan, Isabelle; Lebreton, Frederique; Bussel, Bernard
To determine if the vastus intermedius nerve can be blocked by using surface coordinates and to measure the effects of selective nerve block on quadriceps spasticity and immediate gait. Case series. Physical medicine and rehabilitation department of a university hospital. Twelve patients with hemiplegia disabled by quadriceps overactivity. Anesthesic block of the vastus intermedius by using surface coordinates, femoral nerve stimulation before and after block, and surface electrodes recording of the amplitude of the maximum direct motor response of each head of the quadriceps. Assessment of spasticity, voluntary knee extension velocity, speed of gait, and knee flexion when walking. To be effective, the puncture point (.29 of thigh length and 2cm lateral) had to be slightly modified to 1cm laterally from a point situated at 0.2 of the thigh length. A selective block of the vastus intermedius could not be achieved, but a block of the vastus lateralis was always achieved, twice associated with a block of the vastus intermedius, resulting in decreased quadriceps spasticity, no changes in gait parameters, no decrease in voluntary knee extension velocity, and subjective improvement in gait for 3 patients. Selective block of the vastus lateralis with or without the vastus intermedius can be achieved by using surface coordinates without any dramatic effect on knee extension velocity, and it could be useful for phenol or alcohol block or surgical neurotomy. Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation
Eghtesadi, Marzieh; Leroux, Elizabeth; Vargas-Schaffer, Grisell
Background The great auricular nerve is a cutaneous branch of the cervical plexus originating from the C2 and C3 spinal nerves. It innervates the skin over the external ear, the angle of the mandible and the parotid gland. It communicates with the ansa cervicalis. Great auricular neuralgia is rarely diagnosed in clinical practice and can be refractory. We present a new approach using ultrasound-guided nerve blocks. Case We present a case of a 41-year-old female with paroxysmal ear pain accompanied by dysautonomia, tingling in the tongue, dysphagia, dysarthria and abdominal symptoms. No significant findings were found on cervical and brain imaging. The patient responded partially to a great auricular nerve block. A combined approach using this block with facet block of C2 and C3 induced a more pronounced and prolonged benefit. Conclusion Great auricular neuralgia is not often encountered in practice and can be accompanied by symptoms originating from the ansa cervicalis network. A combined approach of nerve blocks can be considered in refractory cases. PMID:28255253
Ridenour, S.; Reader, A.; Beck, M.; Weaver, J.
The purpose of this prospective, randomized, double-blind study was to determine the anesthetic efficacy of a buffered lidocaine with epinephrine solution compared to a combination buffered lidocaine with epinephrine plus hyaluronidase solution in inferior alveolar nerve blocks. Thirty subjects randomly received an inferior alveolar nerve block using 1 of the 2 solutions at 2 separate appointments using a repeated-measures design. Mandibular anterior and posterior teeth were blindly pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive readings of 80 were obtained. A postoperative survey was used to measure pain and trismus. The results demonstrated 100% of the subjects had profound lip numbness with both solutions for inferior alveolar nerve blocks. The anesthetic success rates for individual teeth ranged from 20 to 80%. There were no significant differences (P > .05) between the 2 solutions. However, the combination lidocaine/hyaluronidase solution resulted in a significant increase in postoperative pain and trismus. It was concluded that adding hyaluronidase to a buffered lidocaine solution with epinephrine did not statistically increase the incidence of pulpal anesthesia in inferior alveolar nerve blocks and, because of its potential tissue damaging effect, it should not be added to local anesthetic solutions for inferior alveolar nerve blocks. PMID:11495405
Kim, Yeon Dong; Yu, Jae Yong; Shim, Junho; Heo, Hyun Joo
Background Recently, ultrasound has been commonly used. Ultrasound-guided interscalene brachial plexus block (IBPB) by posterior approach is more commonly used because anterior approach has been reported to have the risk of phrenic nerve injury. However, posterior approach also has the risk of causing nerve injury because there are risks of encountering dorsal scapular nerve (DSN) and long thoracic nerve (LTN). Therefore, the aim of this study was to evaluate the risk of encountering DSN and LTN during ultrasound-guided IBPB by posterior approach. Methods A total of 70 patients who were scheduled for shoulder surgery were enrolled in this study. After deciding insertion site with ultrasound, awake ultrasound-guided IBPB with nerve stimulator by posterior approach was performed. Incidence of muscle twitches (rhomboids, levator scapulae, and serratus anterior muscles) and current intensity immediately before muscle twitches disappeared were recorded. Results Of the total 70 cases, DSN was encountered in 44 cases (62.8%) and LTN was encountered in 15 cases (21.4%). Both nerves were encountered in 10 cases (14.3%). Neither was encountered in 21 cases (30.4%). The average current measured immediately before the disappearance of muscle twitches was 0.44 mA and 0.50 mA at DSN and LTN, respectively. Conclusions Physicians should be cautious on the risk of injury related to the anatomical structures of nerves, including DSN and LTN, during ultrasound-guided IBPB by posterior approach. Nerve stimulator could be another option for a safer intervention. Moreover, if there is a motor response, it is recommended to select another way to secure better safety. PMID:27413483
Redborg, Kirsten E; Sites, Brian D; Chinn, Christopher D; Gallagher, John D; Ball, Perry A; Antonakakis, John G; Beach, Michael L
: During ankle block performance, anesthetizing the sural nerve is important for generating complete anesthesia of the lateral aspect of the foot. We hypothesized that an ultrasound-guided perivascular approach, utilizing the lesser saphenous vein as a reference, would prove more successful than a conventional approach based on surface landmarks. : Eighteen healthy volunteers were prospectively randomized into this controlled and blinded study. Each subject was placed prone and the right ankle was randomized to receive either an ultrasound-guided perivascular sural nerve block (group US) or a traditional landmark-based sural nerve block (group TRAD). The subject's left ankle then received the alternate approach. The ultrasound technique relied on injecting local anesthetic circumferentially around the lesser saphenous vein. All blocks were performed with 5 mL of 3% chloroprocaine. We evaluated sensory block to ice and pinprick. Secondary outcome variables included performance times, number of needle passes, participant satisfaction, and presence of any complications. : At the midfoot position, testing at 10 minutes after block placement revealed a loss of sensation to ice in 94% (complete in 78% and partial in 16%) in the US group versus 56% in the TRAD group (complete in 28%, partial in 28%) (P <.01). Complete loss of sensation to ice persisted in 33% of the US group as compared with 6% in the TRAD group at 60 minutes (P <.05). A similar pattern was observed when the blocks were tested with pinprick. Ultrasound-guided blocks took longer to perform on average than the traditional blocks (mean difference of 102 seconds, P <.001). The ultrasound block was subjectively felt to be denser by 88% of the subjects (P =.001). : Ultrasound guidance using the lesser saphenous vein as a reference point results in a more complete and longer lasting sural nerve block than does a traditional approach using surface landmarks.
Cok, Oya Yalcin; Eker, H Evren; Cok, Tayfun; Akin, Sule; Aribogan, Anis; Arslan, Gulnaz
Pudendal neuralgia is a type of neuropathic pain experienced predominantly while sitting, and causes a substantial decrease in quality of life in affected patients. Pudendal nerve block is a diagnostic and therapeutic option for pudendal neuralgia. Transsacral block at S2 through S4 results in pudendal nerve block, which is an option for successful relief of pain due to pudendal nerve injury. Herein is reported blockade of S2 through S4 using lidocaine and methylprednisolone for successful treatment of pudendal neuralgia in 2 patients with severe chronic vaginal pain. The patients, aged 44 and 58 years, respectively, were referred from the Gynecology Department to the pain clinic because of burning, stabbing, electric shock-like, unilateral pain localized to the left portion of the vagina and extending to the perineum. Their initial pain scores were 9 and 10, respectively, on a numeric rating scale. Both patients refused pudendal nerve block using classical techniques. Therefore, diagnostic transsacral S2-S4 nerve block was performed using lidocaine 1%, and was repeated using lidocaine 1% and methylprednisolone 80 mg after confirming block efficiency as demonstrated by an immediate decrease in pain scores. After 1 month, pain scores were 1 and 0, respectively, and both patients were free of pain at 6-month follow up. It is suggested that blockade of S2 through S4 using lidocaine and methylprednisolone is an effective treatment option in patients with chronic pudendal neuralgia when traditional pudendal nerve block is not applicable. Copyright © 2011 AAGL. Published by Elsevier Inc. All rights reserved.
Nejati, Amir; Teymourian, Houman; Behrooz, Leili; Mohseni, Gholamreza
Pain is the most common complaint of patients referring to emergency department (ED). Considering the importance of pain management in ED, this study aimed to investigate the efficacy and feasibility of ultrasound-guided nerve blocks in this setting. 46 patients who came to the ED with injured extremities were enrolled in the study and received either femoral, axillary or sciatic nerve block depending on their site of injury (1.5 mg Bupivacaine per kg of patient's weight). Patients were asked about their level of pain before and after receiving the nerve block based on numerical rating scale. The difference between pre and post block pain severity was measured. Both patients and physicians were asked about their satisfaction with the nerve block in 5 tiered Likert scale. 46 patients with the mean age of 37.5 ± 12.5 years (8-82 years) received ultrasound-guided nerve block (84.8% male). 6 Sciatic, 25 axillary, and 15 femoral nerve blocks were performed. Mean pain severity on NRS score at the time of admission was 8.1 ± 1.4, which reduced to 2.04 ± 2.06 after block. 25 (54.3%) patients were highly satisfied (Likert scale 5), 15 (32.6%) were satisfied (Likert scale 4), 3 (6.5%) were neutral and had no opinion (Likert scale 3), 1 (2.1%) was not satisfied (Likert scale 2), and 2 (4.3%) were highly unsatisfied (Likert scale 1). There was no significant difference among the satisfaction scores within the three block locations (p = 0.8). There was no significant difference in physicians' level of satisfaction between the three block locations either (p = 0.9). 1 (2.1%) case of agitation and tachycardia and 1 (2.1%) case of vomiting were observed after the procedure. Ultrasound-guided nerve block of extremities is a safe and effective method that can be used for pain management in the ED. It results in high levels of satisfaction among both patients and physicians.
Nejati, Amir; Teymourian, Houman; Behrooz, Leili; mohseni, Gholamreza
Introduction: Pain is the most common complaint of patients referring to emergency department (ED). Considering the importance of pain management in ED, this study aimed to investigate the efficacy and feasibility of ultrasound-guided nerve blocks in this setting. Methods: 46 patients who came to the ED with injured extremities were enrolled in the study and received either femoral, axillary or sciatic nerve block depending on their site of injury (1.5 mg Bupivacaine per kg of patient’s weight). Patients were asked about their level of pain before and after receiving the nerve block based on numerical rating scale. The difference between pre and post block pain severity was measured. Both patients and physicians were asked about their satisfaction with the nerve block in 5 tiered Likert scale. Results: 46 patients with the mean age of 37.5 ± 12.5 years (8-82 years) received ultrasound-guided nerve block (84.8% male). 6 Sciatic, 25 axillary, and 15 femoral nerve blocks were performed. Mean pain severity on NRS score at the time of admission was 8.1 ± 1.4, which reduced to 2.04 ± 2.06 after block. 25 (54.3%) patients were highly satisfied (Likert scale 5), 15 (32.6%) were satisfied (Likert scale 4), 3 (6.5%) were neutral and had no opinion (Likert scale 3), 1 (2.1%) was not satisfied (Likert scale 2), and 2 (4.3%) were highly unsatisfied (Likert scale 1). There was no significant difference among the satisfaction scores within the three block locations (p = 0.8). There was no significant difference in physicians’ level of satisfaction between the three block locations either (p = 0.9). 1 (2.1%) case of agitation and tachycardia and 1 (2.1%) case of vomiting were observed after the procedure. Conclusion: Ultrasound-guided nerve block of extremities is a safe and effective method that can be used for pain management in the ED. It results in high levels of satisfaction among both patients and physicians.
Reilly, Karen T.; Schieber, Marc H.; McNulty, Penelope A.
During ischemic nerve block of an extremity, the cortical representations of muscles proximal to the block are known to expand, increasing the overlap of different muscle representations. Such reorganization mimics that seen in actual amputees. We investigated whether such changes degrade voluntary control of muscles proximal to the block. Nine subjects produced brief, isometric flexion force selectively with each fingertip before, during, and after ischemic block at the wrist. We recorded the isometric force exerted at the distal phalanx of each digit, along with electromyographic (EMG) activity from intrinsic and extrinsic finger muscles. Despite paralysis of the intrinsic hand muscles, and associated decrements in the flexion forces exerted by the thumb, index, and little fingers, the selectivity of voluntary finger flexion forces and of EMG activity in the extrinsic finger muscles that generated these forces remained unchanged. Our observations indicate that during ischemic nerve block, reorganization does not eliminate or degrade motor representations of the temporarily deafferented and paralyzed fingers. PMID:18431564
Tüfek, Adnan; Tokgöz, Orhan; Karaman, Haktan
Hiccups have more than 100 etiologies. The most common etiology has gastrointestinal origins, related mainly to gastric distention and gastroesophageal reflux disease. Intractable hiccups are rare but may present as a severe symptom of various diseases. Hiccups are mostly treated with non-invasive or pharmacological therapies. If these therapies fail, invasive methods should be used. Here, we present a patient on whom we performed a blockage of the phrenic nerve with the guidance of a nerve stimulator. The patient also had pneumothorax as a complication. Three hours after intervention, a tube thoracostomy was performed. One week later, the patient was cured and discharged from the hospital. In conclusion, a stimulator provides the benefit of localizing the phrenic nerve, which leads to diaphragmatic contractions. Patients with thin necks have more risk of pneumothorax during phrenic nerve location. PMID:21716608
Moon, Sungjoo; Lee, Seung-Jong; Kim, Euiseong
Hypoesthesia after an inferior alveolar nerve (IAN) block does not commonly occur, but some cases are reported. The causes of hypoesthesia include a needle injury or toxicity of local anesthetic agents, and the incidence itself can cause stress to both dentists and patients. This case presents a hypoesthesia on mental nerve area followed by IAN block anesthesia with 2% lidocaine. Prescription of steroids for a week was performed and periodic follow up was done. After 1 wk, the symptoms got much better and after 4 mon, hypoesthesia completely disappeared. During this healing period, only early steroid medication was prescribed. In most cases, hypoesthesia is resolved within 6 mon, but being aware of etiology and the treatment options of hypoesthesia is important. Because the hypoesthesia caused by IAN block anesthesia is a mild to moderate nerve injury, early detection of symptom and prescription of steroids could be helpful for improvement of the hypoesthesia. PMID:23430216
Sharma, Deepak; Singh, V. P.; Agarwal, Nidhi; Malhotra, M. K.
Context: Sparing of obturator nerve is a common problem encountered during transurethral resection of bladder tumor (TURBT) under spinal anesthesia. Aims: To evaluate and compare obturator nerve block (ONB) by two different techniques during TURBT. Settings and Design: This is prospective observational study. Subjects and Methods: Forty adult male patients from the American Society of Anesthesiologists Class I–IV planned to undergo TURBT under spinal anesthesia were divided into two groups of twenty each. In one group, ONB was performed with nerve locator. In other group, transvesical nerve block was performed with a cystoscope. The primary endpoints of this study were the occurrence of adductor reflex, ability to resect the tumor, and number of surgical interruptions. A number of transfusions required and bladder perforation were the secondary endpoints. Results: There was statistically significant difference between the groups for resection without adductor jerk, resection with a minimal jerk, and unresectable with high-intensity adductor jerk. Bleeding was observed in both groups and one bladder perforation was encountered. Conclusions: We conclude that ONB, when administered along with spinal anesthesia for TURBT, is extremely safe and effective method of anesthesia to overcome adductor contraction. ONB with nerve locator appears to be more effective method compared to the transvesical nerve block. PMID:28298765
Bang, Seung Uk; Kim, Yee Suk; Kwon, Woo Jin; Lee, Sang Mook; Kim, Soo Hyang
General anesthesia and central neuraxial blockades in patients with severe Duchenne muscular dystrophy are associated with high risks of complications, including rhabdomyolysis, malignant hyperthermia, hemodynamic instability, and postoperative mechanical ventilation. Here, we describe peripheral nerve blocks as a safe approach to anesthesia in a patient with severe Duchenne muscular dystrophy who was scheduled to undergo surgery. A 22-year-old male patient was scheduled to undergo reduction and internal fixation of a left distal femur fracture. He had been diagnosed with Duchenne muscular dystrophy at 5 years of age, and had no locomotive capability except for that of the finger flexors and toe extensors. He had developed symptoms associated with dyspnea 5 years before and required intermittent ventilation. We blocked the femoral nerve, lateral femoral cutaneous nerve, and parasacral plexus under ultrasound on the left leg. The patient underwent a successful operation using peripheral nerve blocks with no complications. In conclusion general anesthesia and central neuraxial blockades in patients with severe Duchenne muscular dystrophy are unsafe approaches to anesthesia because of hemodynamic instability and respiratory depression. Peripheral nerve blocks are the best way to reduce the risks of critical complications, and are a safe and feasible approach to anesthesia in patients with severe Duchenne muscular dystrophy.
Wright, Edward F
A patient developed a medial pterygoid trismus (myospasm) the day after receiving three inferior alveolar nerve blocks and a routine restoration. She had a significantly restricted mouth opening and significant medial pterygoid muscle pain when she opened beyond the restriction; however, she had no swelling, lymphadenopathy, or fever. A medial pterygoid myospasm can occur secondary to an inferior alveolar nerve block. This disorder generally is treated by the application of heat, muscle stretches, analgesic and/or muscle relaxant ingestion, and a physical therapy referral. The severity of the disorder typically dictates the extent of therapy that is needed.
Droll, Brock; Drum, Melissa; Nusstein, John; Reader, Al; Beck, Mike
The exact reasons for failure of the inferior alveolar nerve (IAN) block are not completely known, but red hair could play a role. The genetic basis for red hair involves specific mutations, red hair color (RHC) alleles, in the melanocortin-1 receptor (MC1R) gene. The purpose of this prospective randomized study was to investigate a possible link between certain variant alleles of the MC1R gene or its phenotypic expression of red hair and the anesthetic efficacy of the IAN block in women. One-hundred twenty-four adult female subjects (62 red haired and 62 dark haired) participated in this study. Dental anxiety was determined in each subject using the Corah Dental Anxiety Questionnaire. The subjects were given 2 cartridges of 2% lidocaine with 1:100,000 epinephrine via the IAN block. Pulpal anesthesia was measured in the posterior and anterior teeth in 4-minute cycles for 60 minutes using an electric pulp tester. The MC1R alleles were genotyped for each subject from cheek cells containing DNA collected using buccal swabs. Women with red hair and women with 2 RHC alleles reported significantly higher levels of dental anxiety compared with women with dark hair or women with 0 RHC alleles. No significant differences in anesthetic success were found between any of the groups for any of the teeth. Red hair and the MC1R gene were significantly linked to higher levels of dental anxiety but were unrelated to success rates of the IAN block in women with healthy pulps. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
Gutiérrez, J; Simeone, C; Gulland, F; Johnson, S
Eye lesions are commonly observed in pinnipeds. Clinical assessment is challenging because animals are often blepharospastic and under inhalant anesthesia the globe rotates ventrally, making observation difficult. Retrobulbar and auriculopalpebral nerve block techniques have been developed in other species to alleviate these difficulties and allow for a more thorough ophthalmic exam. Ocular nerve block techniques were developed for California sea lions (CSLs) (Zalophus californianus) using lidocaine hydrochloride 2%. To develop the retrobulbar block, a variety of needle sizes, anatomic approaches, and volumes of methylene blue were injected into the orbits of 10 CSL cadavers. An optimal technique, based on desired distribution of methylene blue dye into periocular muscles and tissues, was determined to be a two-point (ventrolateral and ventromedial) transpalpebral injection with a 20-ga, 1 1/2-inch needle. This technique was then tested using lidocaine on 26 anesthetized animals prior to euthanasia, and on one case with clinical ocular disease. A dose of 4 mg/kg of lidocaine was considered ideal, with positive results and minimal complications. The retrobulbar block had a 76.9% rate of success (using 4 mg/kg of lidocaine), which was defined as the globe returning at least halfway to its central orientation with mydriasis. No systemic adverse effects were noted with this technique. The auriculopalpebral nerve block was also adapted for CSLs from techniques described in dogs, cattle, and horses. Lidocaine was injected (2-3 ml) by subcutaneous infiltration lateral to the orbital rim, where the auriculopalpebral nerve branch courses over the zygomatic arch. This block was used in five blepharospastic animals that were anesthetized for ophthalmic examinations. The auriculopalpebral nerve block was successful in 60% of the cases, which was defined as reduction or elimination of blepharospasm for up to 3 hr. Success appeared to be dependent more on the location of
Brenneis, C; Kistner, K; Puopolo, M; Jo, S; Roberson, DP; Sisignano, M; Segal, D; Cobos, EJ; Wainger, BJ; Labocha, S; Ferreirós, N; Hehn, C; Tran, J; Geisslinger, G; Reeh, PW; Bean, BP; Woolf, C J
Background and Purpose: Selective nociceptor fibre block is achieved by introducing the cell membrane impermeant sodium channel blocker lidocaine N-ethyl bromide (QX-314) through transient receptor potential V1 (TRPV1) channels into nociceptors. We screened local anaesthetics for their capacity to activate TRP channels, and characterized the nerve block obtained by combination with QX-314. Experimental Approach: We investigated TRP channel activation in dorsal root ganglion (DRG) neurons by calcium imaging and patch-clamp recordings, and cellular QX-314 uptake by MS. To characterize nerve block, compound action potential (CAP) recordings from isolated nerves and behavioural responses were analysed. Key Results: Of the 12 compounds tested, bupivacaine was the most potent activator of ruthenium red-sensitive calcium entry in DRG neurons and activated heterologously expressed TRPA1 channels. QX-314 permeated through TRPA1 channels and accumulated intracellularly after activation of these channels. Upon sciatic injections, QX-314 markedly prolonged bupivacaine's nociceptive block and also extended (to a lesser degree) its motor block. Bupivacaine's blockade of C-, but not A-fibre, CAPs in sciatic nerves was extended by co-application of QX-314. Surprisingly, however, this action was the same in wild-type, TRPA1-knockout and TRPV1/TRPA1-double knockout mice, suggesting a TRP-channel independent entry pathway. Consistent with this, high doses of bupivacaine promoted a non-selective, cellular uptake of QX-314. Conclusions and Implications: Bupivacaine, combined with QX-314, produced a long-lasting sensory nerve block. This did not require QX-314 permeation through TRPA1, although bupivacaine activated these channels. Regardless of entry pathway, the greatly extended duration of block produced by QX-314 and bupivacaine may be clinically useful. PMID:24117225
Wang, C; Sholas, M G; Berde, C B; DiCanzio, J; Zurakowski, D; Wilder, R T
Tachyphylaxis to sciatic nerve blockade in rats correlates with hyperalgesia. Spinal inhibition of nitric oxide synthase with N(G)nitro-L-arginine methyl ester (L-NAME) has been shown to prevent hyperalgesia. Given systemically, L-NAME also prevents tachyphylaxis. The action of L-NAME in preventing tachyphylaxis therefore may be mediated at spinal sites. We compared systemic versus intrathecal potency of L-NAME in modulating tachyphylaxis to sciatic nerve block. Rats were prepared with intrathecal catheters. Three sequential sciatic nerve blocks were placed. Duration of block of thermal nocifensive, proprioceptive and motor responses was recorded. We compared spinal versus systemic dose-response to L-NAME, and examined effects of intrathecal arginine on tachyphylaxis. An additional group of rats underwent testing after T10 spinal cord transection. In these rats duration of sciatic nerve block was assessed by determining the heat-induced flexion withdrawal reflex. L-NAME was 25-fold more potent in preventing tachyphylaxis given intrathecally than intraperitoneally. Intrathecal arginine augmented tachyphylaxis. Spinalized rats exhibited tachyphylaxis to sciatic block. The increased potency of intrathecal versus systemic L-NAME suggests a spinal site of action in inhibiting tachyphylaxis. Descending pathways are not necessary for the development of tachyphylaxis since it occurs even after T10 spinal cord transection. Thus tachyphylaxis, like hyperalgesia, is mediated at least in part by a spinal site of action.
Saracoglu, Seçkin; Bigat, Zekiye; Ertugrul, Fatma; Karsli, Bilge; Kayacan, Nurten
The effectiveness of axillary brachial plexus block (ABPB) performed using peripheral nerve stimulation (PNS) alone was compared with PNS preceded by nerve localization using a pen device, enabling nerve mapping without puncturing the skin. Patients undergoing unilateral hand or forearm surgery suitable for ABPB were randomly assigned to receive either PNS alone (pen - group) or PNS preceded by nerve localization using a pen device (pen + group). Parameters related to the block procedure and patient comfort were assessed. Thirty patients were included in each group. The block performance time was longer in the pen + group than the pen - group despite a reduced number of needle insertions. The complete block rate was higher and intraoperative analgesic usage lower in the pen + group compared with the pen - group. Patient satisfaction and complication rates were similar in the two groups. The pen device seems to be a helpful addition to PNS for ABPB, with improved results in terms of block success and patient comfort, but further studies are needed to confirm these findings.
Gao, Xupeng; Wang, Yu; Chen, Jifeng; Peng, Jiang
The extracellular matrix (ECM) is the naturally occurring substrate that provides a support structure and an attachment site for cells. It also produces a biological signal, which plays an important role in and has significant impact on cell adhesion, migration, proliferation, differentiation, and gene expression. Peripheral nerve repair is a complicated process involving Schwann cell proliferation and migration, 'bands of Büngner' formation, and newborn nerve extension. In the ECM of peripheral nerves, macromolecules are deposited among cells; these constitute the microenvironment of Schwann cell growth. Such macromolecules include collagen (I, III, IV, V), laminin, fibronectin, chondroitin sulfate proteoglycans (CSPGs), and other nerve factors. Collagen, the main component of ECM, provides structural support and guides newborn neurofilament extension. Laminin, fibronectin, CSPGs, and neurotrophic factors, are promoters or inhibitors, playing different roles in nerve repair after injury. By a chemical decellularization process, acellular nerve allografting eliminates the antigens responsible for allograft rejection and maintains most of the ECM components, which can effectively guide and enhance nerve regeneration. Thus, the composition and features of peripheral nerve ECM suggest its superiority as nerve repair material. This review focuses on the structure, function, and application in the tissue engineering nerve construction of the peripheral nerve ECM components.
Ortiz-Pomales, Yan T; Krzyzaniak, Michael; Coimbra, Raul; Baird, Andrew; Eliceiri, Brian P
Recent studies have shown that vagus nerve stimulation (VNS) can block the burn-induced systemic inflammatory response (SIRS). In this study we examined the potential for VNS to modulate vascular permeability (VP) in local sites (i.e. skin) and in secondary sites (i.e. lung) following burn. In a 30% total body surface area burn model, VP was measured using intravascular fluorescent dextran for quantification of the VP response in skin and lung. A peak in VP of the skin was observed 24h post-burn injury, that was blocked by VNS. Moreover, in the lung, VNS led to a reduction in burn-induced VP compared to sham-treated animals subjected to burn alone. The protective effects of VNS in this model were independent of the spleen, suggesting that the spleen was not a direct mediator of VNS. These studies identify a role for VNS in the regulation of VP in burns, with the translational potential of attenuating lung complications following burn.
Ortiz-Pomales, Yan T; Krzyzaniak, Michael; Coimbra, Raul; Baird, Andrew; Eliceiri, Brian P.
Recent studies have shown that vagus nerve stimulation (VNS) can block the burn injury-induced systemic inflammatory response (SIRS). In this study we examined the potential for VNS to modulate vascular permeability (VP) in local sites (i.e. skin) and in secondary sites (i.e. lung) following burn injury. In a 30% total body surface area burn injury model, VP was measured using intravascular fluorescent dextran for quantification of the VP response in skin and lung. A peak in VP of the skin was observed 24 hours post-burn injury, that was blocked by VNS. Moreover, in the lung, VNS led to a reduction in burn-induced VP compared to sham-treated animals subjected to burn injury alone. The protective effects of VNS in this model were independent of the spleen, suggesting that the spleen was not a direct mediator of VNS. These studies identify a role for VNS in the regulation of VP in burns, with the translational potential of attenuating lung complications following burn injury. PMID:22694873
Flores, Stefan; Herring, Andrew A
Adequate emergency department (ED) anesthesia for painful ear conditions, such as ear lacerations or ear abscesses, can be challenging. Much of the sensory innervation of the ear is supplied from the anterior and posterior branches of the greater auricular nerve (GAN). The GAN is a branch of the superficial cervical plexus, which arises from the C2/C3 spinal roots. The GAN innervation includes most of the helix, antihelix, the lobule, and the skin over the mastoid process and parotid gland. Anesthesia of the GAN is commonly performed in emergency medicine as part of a landmark-based ear "ring" block. Recently, a selective ultrasound-guided GAN block has been described. We report the first cases of ultrasound-guided greater auricular nerve block (UGANB) successfully performed in the ED as the sole procedural anesthesia for both an ear laceration and abscess drainage. In addition, we review the relevant anatomy and technical details of the procedure. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Our cases suggest that UGANB is a potentially effective nerve block for ED management of acute ear pain related to procedures involving the tail of the helix and the lobule, such as ear lacerations or ear abscess incision and drainage. Advantages include real-time visualization of the GAN that may increase block success and the decreased volume of local anesthetic required for a block. Copyright © 2016 Elsevier Inc. All rights reserved.
Heard, A M B; Green, R J; Lacquiere, D A; Sillifant, P
Acute trismus can be caused by pain, muscle spasm, swelling or mechanical obstruction. Unfortunately, the cause is not always obvious during pre-operative airway assessment. In this pilot study, we prospectively evaluated mandibular nerve block as a pre-operative tool to identify patients with reversible causes of trismus, namely pain or spasm, in order to allow safe anaesthetic induction. Six patients with unilateral fractured mandibles and trismus received a mandibular nerve block before induction of general anaesthesia. There was an increase in maximal inter-incisor gap after the blocks (median (range) distance: pre-block 16.5 (14-30) and post-block 34 (32-35) mm; p = 0.027), and no further improvement after induction of general anaesthesia (post-induction 37 (30-40) mm; p = 0.276 compared with post-block). There was an improvement in pain scores (p = 0.027), and no side-effects were detected. Pre-operative mandibular nerve blockade appears to reverse trismus caused by pain and muscle spasm, allowing the anaesthetist to decide whether awake intubation is genuinely indicated.
Matsumoto, Hideyuki; Konoma, Yuko; Fujii, Kengo; Hanajima, Ritsuko; Terao, Yasuo; Ugawa, Yoshikazu
Useful diagnostic techniques for the acute phase of sciatic nerve palsy, an entrapment neuropathy, are not well established. The aim of this paper is to demonstrate the diagnostic utility of magnetic sacral motor root stimulation for sciatic nerve palsy. We analyzed the peripheral nerves innervating the abductor hallucis muscle using both electrical stimulations at the ankle and knee and magnetic stimulations at the neuro-foramina and conus medullaris levels in a patient with sciatic nerve palsy at the level of the piriformis muscle due to gluteal compression related to alcohol consumption. On the fourth day after onset, magnetic sacral motor root stimulation using a MATS coil (the MATS coil stimulation method) clearly revealed a conduction block between the knee and the sacral neuro-foramina. Two weeks after onset, needle electromyography supported the existence of the focal lesion. The MATS coil stimulation method clearly revealed a conduction block in the sciatic nerve and is therefore a useful diagnostic tool for the abnormal neurophysiological findings associated with sciatic nerve palsy even at the acute phase.
Yun, Hongmin; Lathrop, Kira L; Hendricks, Robert L
Herpes simplex virus type 1 (HSV-1) is a neurotrophic virus that can cause herpes stromal keratitis (HSK), a severe corneal inflammation that can lead to corneal scarring and blindness. This study identified neurologic changes that occur in HSV-1-infected corneas and related them to HSV-1-induced immunopathology. Corneas of BALB/c and C57BL/6 mice were infected with HSV-1 strains that induce HSK. Changes in sensory nerves were identified by immunofluorescence staining of sensory and sympathetic nerves for substance P (SP) and tyrosine hydroxylase (TH), respectively, and confocal microscopic examination. Some mice received superior cervical ganglionectomy (SCGx) to eliminate sympathetic nerves from the cornea. Normal corneas exclusively expressed sensory nerves that entered the stroma as large nerve stalks, branched to form a plexus at the epithelial/stromal interface, and extended termini into the epithelium. These nerves completely retracted from the infected cornea and were replaced by sympathetic nerves that sprouted extensively to hyperinnervate the corneal stroma but failed to form a plexus or extend termini into the epithelium. The hyperinnervating nerves expressed the sympathetic nerve marker TH and their invasion was blocked by performing SCGx. Moreover, the corneal opacity and neovascularization that normally characterizes HSK in this mouse model were largely abrogated by SCGx. Sensory nerves reinnervated infected corneas following SCGx, reformed a nerve plexus, and extended termini into the epithelium resulting in recovery of corneal sensitivity. Sympathetic nerves have a central role in HSK in mice, preventing reinnervation by sensory nerves and promoting severe and persistent corneal inflammation.
Enomoto, Masataka; Lascelles, B Duncan X; Gerard, Mathew P
Objectives Anatomical and methodological detail is lacking regarding local anesthetic peripheral nerve block techniques for distal pelvic limb surgery in cats. The aim of this study was to develop, describe and test nerve block methods based on cadaveric dissections and dye injections. Methods Ten pairs of feline pelvic limbs (n = 20) were dissected and the tibial nerve (T n.), common fibular (peroneal) nerve (CF n., and its two branches, the superficial fibular [peroneal] nerve [SpF n.] and the deep fibular [peroneal] nerve [DpF n.]) and the saphenous nerve (Sa n.) were identified. Based on these dissections, a 'distal crus block' (selective blockade of the CF n., T n. and Sa n.) and a 'distal pes block' (selective blockade of the SpF n., DpF n., T n. and Sa n.) were developed for surgical procedures in two different regions of the distal pelvic limb. Techniques were tested using new methylene blue (NMB) dye injections in feline pelvic limbs (n = 12). Using a 25 G × 5/8 inch needle and 1 ml syringe, 0.1 ml/kg of NMB dye solution was injected at the site of the CF n., and 0.05 ml/kg was injected at the sites of the SpF n., DpF n., Sa n. and T n. The length and circumference (fully or partially stained) of each stained nerve were measured. Results Positive staining of nerves was observed in 12/12 limbs. The lengths stained for the CF n., DpF n., SpF n., Sa n. and T n. were 27.19 ± 7.13, 20.39 ± 5.57, 22.82 ± 7.13, 30.89 ± 6.99 and 25.16 ± 8.09 mm, respectively. The nerves were fully stained in 12, 12, 10, 11 and 11 out of 12 limbs, respectively. Conclusions and relevance These two, three-point injection methods may be an effective perioperative analgesia technique for feline distal pelvic limb procedures.
Chang, Ke-Vin; Hung, Chen-Yu; Wang, Tyng-Guey; Yang, Rong-Sen; Sun, Wei-Zen; Lin, Chih-Peng
The classic suprascapular nerve block has limitations, such as postural requirements and lack of direct nerve visualization. This series investigated the analgesic effect of ultrasound-guided supraclavicular suprascapular nerve blocks in patients with malignancy-associated shoulder pain. Ablative radiofrequency lesioning of the suprascapular nerve in 6 patients provided substantial pain relief. The mean distance from the suprascapular nerve to the brachial plexus was 8.05 mm, and the mean angle of needle entry was 20.6°. This approach appears to be effective in relieving malignancy-associated shoulder pain and is tolerated by patients unable to sit or lie prone.
Taha, Ahmad Muhammad; Ghoneim, Mohammed Abd-Elfttah
Background: Major lower limb nerve blocks are relatively safe techniques. However, their efficacy for hip hemiarthroplasty is unknown. The objective of this study was to determine the effectiveness of combined femoral, sciatic, obturator and lateral femoral cutaneous (LFC) nerve blocks in providing adequate anesthesia for hip hemiarthroplasty. Materials and Methods: A total of 20 patients with fracture neck femur; who underwent hip hemiarthroplasty, participated in this observational study. In the induction room, all patients received ultrasound-guided femoral, proximal obturator, LFC and parasacral sciatic nerve blocks in addition to local infiltration at the proximal site of the skin incision. Anesthesia was considered to be adequate only if the surgery was completed without any requirement for opioid administration. Results: All patients (100% [95% confidence interval, 86-100%]) had adequate anesthesia. Seventeen patients (85% [95% confidence interval, 63-96%] had mild discomfort during the reduction of the prosthetic femur head back into the hip socket; however, no supplementary analgesics were required. Conclusion: The combined femoral, sciatic, obturator and LFC nerve blocks in addition to local infiltration at the proximal site of skin incision could provide adequate anesthesia for hip hemiarthroplasty. Light sedation before reduction of the prosthetic femur head back into the hip socket is advisable. PMID:25191186
Won, Yu-Jin; Kang, Sang-Hoon
Efforts to apply augmented reality (AR) technology in the medical field include the introduction of AR techniques into dental practice. The present report introduces a simple method of applying AR during an inferior alveolar nerve block, a procedure commonly performed in dental clinics.
Efforts to apply augmented reality (AR) technology in the medical field include the introduction of AR techniques into dental practice. The present report introduces a simple method of applying AR during an inferior alveolar nerve block, a procedure commonly performed in dental clinics. PMID:28879340
Ullrich, Sebastian; Frommen, Thorsten; Rossaint, Rolf; Kuhlen, Torsten
In this paper, we present a simulator for regional anaesthesia for nerve blocks in the axillary plexus region. We use a novel approach based on electric distance to simulate electronic impulse transmission through soft tissue. The traversal of electrons emitted from the needle tip is calculated by modified pathfinding algorithms. Kinematic algorithms visualize the motor response of the forearm by skeletal animation.
Fantony, Joseph J.; Routh, Jonathan C.
We report the first documented case of high flow priapism after circumcision with dorsal penile nerve block. A 7-year-old male who had undergone circumcision three years before presented to our institution with a 3-year history of persistent nonpainful erections. Workup revealed a high flow priapism and, after discussion of the management options, the patient's family elected continued observation. PMID:27648333
Parthasarathy, S.; Sripriya, R.
Mandibulo facial injuries present special problems to the anesthesiologist in terms of the difficult airway. Hence, if regional anesthesia could be possible, it necessarily removes the major concern with airway access. We present a case of bilateral mandibular condylar fracture dislocation with the maxillary and mandibular nerve blocks on both sides. The surgery went on smoothly without any perioperative problems. PMID:26417146
Taboada, M; Bascuas, B; Oliveira, J; Del Río, S; Rodríguez, J; Cortés, J; Alvarez Escudero, J
Lateral approaches to the sciatic nerve through the popliteal fossa have recently been described as useful for providing adequate anesthesia and postoperative analgesia for foot and ankle surgery. Numerous publications have appeared on the approach in recent years, proposing new anatomical landmarks to facilitate location of the nerve, reduce the rate of complications, and increase the rate of success. When the lateral popliteal approach has been compared to other approaches to the sciatic nerve, similar success rates have been observed. However, when this technique is used certain factors must be borne in mind because they can influence both latency time and success. This review describes the lateral popliteal approach, its main variations, the factors that can affect latency time or success, and the possibility of providing continuous analgesia. We also sought to compare this approach to other techniques for blocking the sciatic nerve.
da Costa, Rodrigo F Madeiro; Martinez, Ana M Blanco; Ferreira, Sergio T
Preventing the harm caused by nerve degeneration is a major challenge in neurodegenerative diseases and in various forms of trauma to the nervous system. The aim of the current work was to investigate the effects of systemic administration of 2,4-dinitrophenol (DNP), a compound with newly recognized neuroprotective properties, on sciatic-nerve degeneration following a crush injury. Sciatic-nerve injury was induced by unilateral application of an aneurysm clip. Four groups of mice were used: uninjured, injured treated with vehicle (PBS), injured treated with two intraperitoneal doses of DNP (0.06 mg DNP/kg every 24 h), and injured treated with four doses of DNP (every 12 h). Animals were sacrificed 48 h post injury and both injured and uninjured (contralateral) sciatic nerves were processed for light and electron microscopy. Morphometric, ultrastructural, and immunohistochemical analysis of injured nerves established that DNP prevented axonal degeneration, blocked cytoskeletal disintegration, and preserved the immunoreactivity of amyloid precursor protein (APP) and Neuregulin 1 (Nrg1), proteins implicated in neuronal survival and myelination. Functional tests revealed preservation of limb function following injury in DNP-treated animals. Results indicate that DNP prevents nerve degeneration and suggest that it may be a useful small-molecule adjuvant in the development of novel therapeutic approaches in nerve injury.
Thapa, Deepak; Ahuja, Vanita
Plantar fasciitis (PF) is the most common cause of chronic heel pain which may be bilateral in 20 to 30% of patients. It is a very painful and disabling condition which can affect the quality of life. The management includes both pharmacological and operative procedures with no single proven effective treatment modality. In the present case series, we managed three patients with PF (one with bilateral PF). Following a diagnostic medial calcaneal nerve (MCN) block at its origin, we observed reduction in verbal numerical rating scale (VNRS) in all the three patients. Two patients has relapse of PF pain which was managed with MCN block followed with pulsed radio frequency (PRF). All the patients were pain-free at the time of reporting. This case series highlights the possible role of combination of diagnostic MCN block near its origin followed with PRF as a new modality in management of patients with PF.
Hascalovici, Jacob R; Robbins, Matthew S
The objective of this study is to provide demographical and clinical descriptions of patients age 65 years old and older who were treated with peripheral nerve blocks (PNBs) at our institution and evaluate the safety and efficacy of this treatment. Headache disorders are common, disabling chronic neurological diseases that often persist with advancing age. Geriatric headache management poses unique therapeutic challenges because of considerations of comorbidity, drug interactions, and adverse effects. Peripheral nerve blocks are commonly used for acute and short-term prophylactic treatment for headache disorders and may be a safer alternative to standard pharmacotherapy in this demographic. We performed a single center, retrospective chart review of patients at least 65 years of age who received peripheral nerve blocks for headache management over a 6 year period. Sixty-four patients were mostly female (78%) with an average age of 71 years (range 65-94). Representative headache diagnoses were chronic migraine 50%, episodic migraine 12.5%, trigeminal autonomic cephalalgia 9.4%, and occipital neuralgia 7.8%. Average number of headache days/month was 23. Common comorbidities were hypertension 48%, hyperlipidemia 42%, arthritis 27%, depression 47%, and anxiety 33%. Eighty-nine percent were prescribed at least 1 medication fulfilling the Beers criteria. The average number of peripheral nerve blocks per patient was 4. Peripheral nerve blocks were felt to be effective in 73% for all headaches, 81% for chronic migraine, 75% for episodic migraine, 67% for chronic tension type headache, 67% for new daily persistent headache, and 60% for occipital neuralgia. There were no adverse events related to PNBs reported. PNBs might be a safe and effective alternative headache management strategy for older adults. Medical and psychiatric comorbidities, medication overuse, and Beers list medication rates were extraordinarily high, giving credence to the use of peripherally administered
Burke, W; Cottee, L J; Garvey, J; Kumarasinghe, R; Kyriacou, C
Using a technique described previously, we have applied pressure to the optic nerve of a cat sufficient to cause conduction block of the t1 response (the response of the Y optic nerve fibres). A greater pressure, usually sufficient to cause a transient block of the t2 response (the response of the X fibres), leads to degeneration of the Y axons caudal to the block. This is demonstrated by the disappearance of the t1 response in this region after 4-5 days and by the presence in electron micrographs of degenerating large (Y) fibres. Some small fibres also show degeneration, but the medium (X) fibres are largely spared. The time course of loss of response in the Y fibres is similar whether the loss is due to a pressure block or to enucleation, suggesting that the pressure block as used by us causes a disruption of the axon. If the pressure is great enough to block part of the t2 response (X fibres) there is also a similarity in time course of loss of response to that following enucleation. Both for the enucleated and the pressure-blocked cat the t2 response fails about 1 day before the t1 response. This is in apparent disagreement with the morphological findings in the literature, confirmed here, indicating an earlier degeneration of the larger fibres. The post-synaptic response in the lateral geniculate nucleus to the t1 input (the r1 response) also fails about 1 day before the t1 response. In the visual cortex the loss of the r1 response reveals more clearly than is normally possible an r2 response, the response of the X optic radiation fibres. The response in the optic nerve or tract to a bright flash of light is dominated by the response of the Y fibres. When these are blocked the response is greatly reduced. Images Plate 1 PMID:3795079
Yilmaz, Saim Ceken, Kagan; Alimoglu, Emel; Sindel, Timur
Endovenous laser ablation may be associated with significant pain when performed under standard local tumescent anesthesia. The purpose of this study was to investigate the efficacy of femoral and sciatic nerve blocks for analgesia during endovenous ablation in patients with lower extremity venous insufficiency. During a 28-month period, ultrasound-guided femoral or sciatic nerve blocks were performed to provide analgesia during endovenous laser ablation in 506 legs and 307 patients. The femoral block (n = 402) was performed at the level of the inguinal ligament, and the sciatic block at the posterior midthigh (n = 124), by injecting a diluted lidocaine solution under ultrasound guidance. After the blocks, endovenous laser ablations and other treatments (phlebectomy or foam sclerotherapy) were performed in the standard fashion. After the procedures, a visual analogue pain scale (1-10) was used for pain assessment. After the blocks, pain scores were 0 or 1 (no pain) in 240 legs, 2 or 3 (uncomfortable) in 225 legs, and 4 or 5 (annoying) in 41 legs. Patients never experienced any pain higher than score 5. The statistical analysis revealed no significant difference between the pain scores of the right leg versus the left leg (p = 0.321) and between the pain scores after the femoral versus sciatic block (p = 0.7). Ultrasound-guided femoral and sciatic nerve blocks may provide considerable reduction of pain during endovenous laser and other treatments, such as ambulatory phlebectomy and foam sclerotherapy. They may make these procedures more comfortable for the patient and easier for the operator.
Worm, Bjarne Skjødt; Krag, Mette; Jensen, Kenneth
With the advancement of ultrasound-guidance for peripheral nerve blocks, still pictures from representative ultrasonograms are increasingly used for clinical procedure documentation of the procedure and for educational purposes in textbook materials. However, little is actually known about the clinical and educational usefulness of these still pictures, in particular how well nerve structures can be identified compared to real-time ultrasound examination. We aimed to quantify gross visibility or ultrastructure using still picture sonograms compared to real time ultrasound for trainees and experts, for large or small nerves, and discuss the clinical or educational relevance of these findings. We undertook a clinical study to quantify the maximal gross visibility or ultrastructure of seven peripheral nerves identified by either real time ultrasound (clinical cohort, n = 635) or by still picture ultrasonograms (clinical cohort, n = 112). In addition, we undertook a study on test subjects (n = 4) to quantify interobserver variations and potential bias among expert and trainee observers. When comparing real time ultrasound and interpretation of still picture sonograms, gross identification of large nerves was reduced by 15% and 40% by expert and trainee observers, respectively, while gross identification of small nerves was reduced by 29% and 66%. Identification of within-nerve ultrastructure was even less. For all nerve sizes, trainees were unable to identify any anatomical structure in 24 to 34%, while experts were unable to identify anything in 9 to 10%. Exhaustive ultrasonography experience and real time ultrasound measurements seem to be keystones in obtaining optimal nerve identification. In contrast the use of still pictures appears to be insufficient for documentation as well as educational purposes. Alternatives such as video clips or enhanced picture technology are encouraged instead of still pictures extracted from basic ultrasonograms.
Yee, T C; Kalichman, M W
To test the hypothesis that the dose requirement for local anesthetics is changed in aged animals, the effects of two different local anesthetics on nerve conduction block were tested in young and old rats. Young (6 months) and old (27 months) male Fisher-344 rats were anesthetized with intraperitoneal pentobarbital and diazepam. Stimulating electrodes were placed in the sciatic notch and in the ankle and recording electrodes were placed distally in the ipsilateral foot to record evoked electrical activity of the interosseous muscles. Motor nerve conduction velocity was significantly less in old (48.8 +/- 3.9, mean +/- SD m.sec-1) than in young rats (56.4 +/- 10.3 m.sec-1) (P < 0.05). To test the effects of aging on conduction block, equipotent doses of bupivacaine (0.2%), an amide-linked local anesthetic, or procaine (0.6%), an ester-linked local anesthetic, were injected next to exposed sciatic nerves and evoked electrical activity was monitored following repeated stimulation at the sciatic notch. At 10 minutes after injection, bupivacaine produced significantly greater nerve block in old rats (100 +/- 0.0%) than young rats (29.8 +/- 41.6%) (P < 0.01); the difference for procaine (old 67.5 +/- 40.4% vs. young 30.4 +/- 35.3%) was not statistically significant. The lower dose requirement for bupivacaine, and the apparent differences compared to procaine, may have implications for the use of local anesthetics in an aging patient population.
Ranjit, S; Pradhan, B B
Background Positioning patients with fractured femur for subarachnoid block is painful. Intravenous analgesics or peripheral nerve block like femoral nerve block or fascia iliaca compartment block are some of the available techniques to reduce pain. We compared the efficacy of femoral nerve block and intravenous fentanyl in providing effective analgesia before positioning for subarachnoid block. Objective This study was designed to compare between ultrasound guided femoral nerve block with lignocaine and intravenous fentanyl in providing effective analgesia before positioning patient with femur fracture in sitting position for subarachnoid block. Method Forty patients undergoing surgery for femur fracture were randomized to either femoral nerve block (FNB) or intravenous fentanyl (IVF) group. Group FNB (n=20) received 20 ml of 2% lignocaine around femoral nerve under ultrasound guidance. IVF group (n=20) received 2 mc/kg of fentanyl intravenously. Pain score on effected limb was assessed after five minutes. If VAS was ≤ 4, the patient was positioned in sitting for subarachnoid block. On failure to achieve this with the above treatment, intravenous fentanyl 0.5 mc/kg was administered and repeated as necessary before positioning. VAS during positioning was documented and compared between the two groups. Similarly, secondary outcomes of the intervention: quality of patient position, rescue analgesia and duration of the procedure were also compared. Data were subjected to Mann Whitney U-test and chi-square test. Level of significance was set at 0.05. Result FNB group had significantly less VAS scores (median) than IVF group :2 vs 3; p=0.037) during positioning for spinal anaesthesia. Procedure time (median) for spinal anaesthesia was also significantly less in FNB than in IVA group (10 vs 12 min; p=0.033) Conclusion Ultrasound guided femoral nerve block was more effective than intravenous fentanyl for reducing pain in patients with proximal femur fracture before
Hung, Yu-Chun; Chen, Chia-Ying; Lirk, Philipp; Wang, Chi-Fei; Cheng, Jen-Kun; Chen, Chien-Chuan; Wang, Ging Kuo; Gerner, Peter
Background and Objectives Magnesium sulfate (MgSO4) is well-known as an antagonist of n-methyl-d-aspartate receptors and was used for intrathecal analgesia a century ago. However, the effects of MgSO4 combined with local anesthetics (LAs) on peripheral nerves are unclear. We tested the hypothesis that MgSO4 could be used as an adjuvant to prolong and intensify conduction block by amide-type LAs in a rat sciatic nerve block model. Further, the mechanism of possible synergy between LAs and MgSO4 was investigated in whole-cell mode patch-clamp experiments. Methods Sciatic nerves were exposed to 2%/73.9mM lidocaine, 0.25%/7.7mM bupivacaine, and 0.5%/15.4mM ropivacaine, with or without addition of 1.25%, 2.5%, or 5% MgSO4/50.7 mM, and nerve block characteristics were assessed. To elucidate the LA-MgSO4 interaction, voltage-dependent inactivation curves were determined in cultured rat GH3 cells expressing neuronal Na+ channels. Results Unexpectedly, the addition of MgSO4 overall significantly shortened the duration of blockade by lidocaine, bupivacaine, and ropivacaine. The steady-state inactivation of Na+ channels in the presence of 300 μM lidocaine was almost unchanged by the addition of 10 mM MgSO4, indicating that MgSO4 does not affect the potency of lidocaine toward the inactivated Na+ channel. Conclusions MgSO4 coadministered with amide-type LAs shortened the duration of sciatic nerve blockade in rats. Therefore, it does not seem to be useful as an adjuvant for peripheral nerve blockade. The mechanism of this observed antagonism is unclear, but appears to be independent of the action of LAs and MgSO4 at the LA receptor within the Na+ channel. PMID:17720112
Xia, Wenfeng; West, Simeon J.; Nikitichev, Daniil I.; Ourselin, Sebastien; Beard, Paul C.; Desjardins, Adrien E.
Accurate identification of tissue structures such as nerves and blood vessels is critically important for interventional procedures such as nerve blocks. Ultrasound imaging is widely used as a guidance modality to visualize anatomical structures in real-time. However, identification of nerves and small blood vessels can be very challenging, and accidental intra-neural or intra-vascular injections can result in significant complications. Multi-spectral photoacoustic imaging can provide high sensitivity and specificity for discriminating hemoglobin- and lipid-rich tissues. However, conventional surface-illumination-based photoacoustic systems suffer from limited sensitivity at large depths. In this study, for the first time, an interventional multispectral photoacoustic imaging (IMPA) system was used to image nerves in a swine model in vivo. Pulsed excitation light with wavelengths in the ranges of 750 - 900 nm and 1150 - 1300 nm was delivered inside the body through an optical fiber positioned within the cannula of an injection needle. Ultrasound waves were received at the tissue surface using a clinical linear array imaging probe. Co-registered B-mode ultrasound images were acquired using the same imaging probe. Nerve identification was performed using a combination of B-mode ultrasound imaging and electrical stimulation. Using a linear model, spectral-unmixing of the photoacoustic data was performed to provide image contrast for oxygenated and de-oxygenated hemoglobin, water and lipids. Good correspondence between a known nerve location and a lipid-rich region in the photoacoustic images was observed. The results indicate that IMPA is a promising modality for guiding nerve blocks and other interventional procedures. Challenges involved with clinical translation are discussed.
Yang, Guangning; Wang, Jicheng; Shen, Bing; Roppolo, James R.; de Groat, William C.; Tai, Changfeng
Objective To determine the functionality of a wireless controlled implantable stimulator designed for stimulation and block of the pudendal nerve. Materials and Methods In 5 cats under α-chloralose anesthesia, the stimulator was implanted underneath the skin on the left side in the lower back along the sacral spine. Two tripolar cuff electrodes were implanted bilaterally on the pudendal nerves in addition to one bipolar cuff electrode that was implanted on the left side central to the tripolar cuff electrode. The stimulator provided high frequency (5-20 kHz) biphasic stimulation waveforms to the two tripolar electrodes and low frequency (1-100 Hz) rectangular pulses to the bipolar electrode. Bladder and urethral pressures were measured to determine the effects of pudendal nerve stimulation (PNS) or block. Results The maximal (70-100 cmH2O) urethral pressure generated by 20 Hz PNS applied via the bipolar electrode was completely eliminated by the pudendal nerve block induced by the high frequency stimulation (6-15 kHz, 6-10 V) applied via the two tripolar electrodes. In a partially filled bladder 20-30 Hz PNS (2-8 V, 0.2 ms) but not 5 Hz stimulation applied via the bipolar electrode elicited a large sustained bladder contraction (45.9±13.4 to 52.0±22 cmH2O). During cystometry, the 5 Hz PNS significantly (P<0.05) increased bladder capacity to 176.5±27.1% of control capacity. Conclusions The wireless controlled implantable stimulator successfully generated the required waveforms for stimulation and block of pudendal nerve, which will be useful for restoring bladder functions after spinal cord injury (SCI). PMID:24320615
Neal, Joseph M
Successful performance of lower-extremity regional anesthesia includes sensory and/or motor block assessment of up to 4 major peripheral nerves. This brief report describes a methodology for the rapid evaluation of lower-extremity anesthesia before surgical incision. Illustrations highlight the techniques for evaluation of sciatic, obturator, lateral femoral cutaneous, and femoral nerve anesthesia. This methodology is based on a Four P's acronym: push, pull, pinch, punt. Accurate assessment of lower-extremity regional anesthesia can be achieved rapidly using The Four Ps evaluation tool.
You, Tae Min
Although inferior alveolar nerve block is one of the most common procedures performed at dental clinics, complications or adverse effects can still occur. On rare occasions, ocular disturbances, such as diplopia, blurred vision, amaurosis, mydriasis, abnormal pupillary light reflex, retrobulbar pain, miosis, and enophthalmos, have also been reported after maxillary and mandibular anesthesia. Generally, these symptoms are temporary but they can be rather distressing to both patients and dental practitioners. Herein, we describe a case of diplopia caused by routine inferior alveolar nerve anesthesia, its related physiology, and management.
Peláez, Raquel; Pascual, Gabriel; Aguilar, José L; Atanassoff, Peter G
In patients with aggressive tumors resistant to conventional pain treatment, regional anaesthesia frequently becomes an alternative therapy. Cervical paravertebral nerve block among several access options to the brachial plexus is barely ever used. We present a case with severe shoulder and upper extremity pain owing to an expanding Pancoast tumor exhibiting compression upon the brachial plexus. Continuous intrathecal morphine infusion and adjuvant treatment was not sufficient to render the patient pain-free. With the addition of paravertebral nerve blockade the patient's pain improved substantially, however without impacting his longevity.
Kumar, Alok; Sharma, DK; Sibi, Maj. E; Datta, Barun; Gogoi, Biraj
Background: The established methods of nerve location were based on either proper motor response on nerve stimulation (NS) or ultrasound guidance. In this prospective, randomised, observer-blinded study, we compared ultrasound guidance with NS for axillary brachial plexus block using 0.5% bupivacaine with the multiple injection techniques. Methods: A total of 120 patients receiving axillary brachial plexus block with 0.5% bupivacaine, using a multiple injection technique, were randomly allocated to receive either NS (group NS, n = 60), or ultrasound guidance (group US, n = 60) for nerve location. A blinded observer recorded the onset of sensory and motor blocks, skin punctures, needle redirections, procedure-related pain and patient satisfaction. Results: The median (range) number of skin punctures were 2 (2–4) in group US and 3 (2–5) in group NS (P < 0.001). No differences were observed in the onset of sensory block in group NS (6.17 ± 1.22 min) and in group US (6.33 ± 0.48 min) (P = 0.16), and in onset of motor block (23.33 ± 1.26 min) in group US and (23.17 ± 1.79 min) in group NS; P > =0.27). Insufficient block was observed in three patient (5%) of group US and four patients (6.67%) of group NS (P > =0.35). Patient acceptance was similarly good in the two groups. Conclusion: Multiple injection axillary blocks with ultrasound guidance provided similar success rates and comparable incidence of complications as compared with NS guidance with 20 ml 0.5% bupivacaine. PMID:25624532
Roberman, Dmitry; Arora, Harendra; Sessler, Daniel I; Ritchey, Michael; You, Jing; Kumar, Priya
An ideal local anesthetic with rapid onset and prolonged duration has yet to be developed. Clinicians use mixtures of local anesthetics in an attempt to combine their advantages. We tested the hypothesis that sequential supraclavicular injection of 1.5% mepivacaine followed 90 secs later by 0.5% ropivacaine speeds onset of sensory block and prolongs duration of analgesia compared with simultaneous injection of the same 2 local anesthetics. We enrolled 103 patients undergoing surgery suitable for supraclavicular anesthesia. The primary outcome was time to 4-nerve sensory block onset in each of the 4 major nerve distributions: median, ulnar, radial, and musculocutaneous. Secondary outcomes included time to onset of first sensory block, time to complete motor block, duration of analgesia, pain scores at rest and with movement, and total opioid consumption. Outcomes were compared using the Kaplan-Meier analysis with the log-rank test or the analysis of variance, as appropriate. Times to 4-nerve sensory block onset were not different between sequential and combined anesthetic administration. The time to complete motor block onset was faster in the combined group as compared with the sequential. There were not significant differences between the 2 randomized groups in other secondary outcomes, such as the time to onset of first sensory block, the duration of analgesia, the pain scores at rest or with movement, or the total opioid consumption. Sequential injection of 1.5% mepivacaine followed 90 secs later by 0.5% ropivacaine provides no advantage compared with simultaneous injection of the same doses. Copyright © 2011 by American Society of Regional Anesthesia and Pain Medicine
Bigby, Jason; Reader, Al; Nusstein, John; Beck, Mike
The purpose of this prospective, randomized, single-blind study was to compare the anesthetic efficacy of lidocaine with epinephrine to lidocaine plus meperidine with epinephrine for inferior alveolar nerve blocks (IAN) in patients with mandibular posterior teeth experiencing irreversible pulpitis. Forty-eight emergency patients diagnosed with irreversible pulpitis of a mandibular posterior tooth randomly received, in a single-blind manner, 36 mg of lidocaine with 18 mug epinephrine or 36 mg of lidocaine with 18 mug of epinephrine plus 36 mg meperidine with 18 mug epinephrine, using a conventional inferior alveolar nerve block. Endodontic access was begun 15 minutes after solution deposition, and all patients were required to have profound lip numbness. Success was defined as no or mild pain (visual analog scale recordings) upon endodontic access or initial instrumentation. The success rate for the inferior alveolar nerve block using the lidocaine solution was 26%, and for the lidocaine/meperidine solution, the success rate was 12%. There was no significant difference (p = 0.28) between the two solutions. In conclusion, for mandibular posterior teeth with irreversible pulpitis, the addition of 36 mg of meperidine to a lidocaine solution administered in a conventional IAN block did not improve the success rate over a standard lidocaine solution.
Saraf, Suma Prahlad; Saraf, Prahlad Annappa; Kamatagi, Laxmikant; Hugar, Santosh; Tamgond, Shridevi; Patil, Jayakumar
Background: The ideal maxillary injection should produce a rapid onset of profound pulpal anesthesia for multiple teeth from a single needle penetration. The main objective is to compare the efficacy of articaine 4% and lidocaine 2% and to compare anterior middle superior alveolar nerve block (AMSANB) and infraorbital nerve block (IONB) for anesthesia of maxillary teeth. Materials and Methods: Forty patients undergoing root canal treatment of maxillary anteriors and premolars were included and randomly divided into four groups of ten each. Group I: patients receiving AMSANB with articaine, Group II: Patients receiving IONB with articaine, Group III: Patients receiving AMSANB with lidocaine, Group IV: Patients receiving IONB with lidocaine. The scores of onset of anesthesia and pain perception were statistically analyzed. Results: Onset of action was fastest for articaine with AMSANB and slowest for lidocaine with IONB by Tukey's test. A significant change was observed in the electrical pulp test readings at onset and at 30 min by paired t-test. All patients experienced mild pain during the procedure recorded by visual analog scale. Conclusion: Articaine 4% proved to be more efficacious than lidocaine 2%, and AMSANB was more advantageous than IONB in securing anesthesia of maxillary anteriors and premolars. PMID:27994313
Uyar Türkyilmaz, Esra; Eryilmaz, Nuray Camgöz; Güzey, Nihan Aydin; Moraloğlu, Özlem
Post-dural puncture headache (PDPH) is an important complication of neuroaxial anesthesia and more frequently noted in pregnant women. The pain is described as severe, disturbing and its location is usually fronto-occipital. The conservative treatment of PDPH consists of bed rest, fluid theraphy, analgesics and caffeine. Epidural blood patch is gold standard theraphy but it is an invasive method. The greater occipital nerve (GON) is formed of sensory fibers that originate in the C2 and C3 segments of the spinal cord and it is the main sensory nerve of the occipital region. GON blockage has been used for the treatment of many kinds of headache. The aim of this retrospective study is to present the results of PDPH treated with GON block over 1 year period in our institute. 16 patients who had been diagnosed to have PDPH, and performed GON block after caesarean operations were included in the study. GON blocks were performed as the first treatment directly after diagnose of the PDPH with levobupivacaine and dexamethasone. The mean VAS score of the patients was 8.75 (±0.93) before the block; 3.87 (±1.78) 10min after the block; 1.18 (±2.04) 2h after the block and 2.13 (±1.64) 24h after the block. No adverse effects were observed. Treatment of PDPH with GON block seems to be a minimal invasive, easy and effective method especially after caesarean operations. A GON block may be considered before the application of a blood patch. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.
Uyar Türkyilmaz, Esra; Camgöz Eryilmaz, Nuray; Aydin Güzey, Nihan; Moraloğlu, Özlem
Post-dural puncture headache (PDPH) is an important complication of neuroaxial anesthesia and more frequently noted in pregnant women. The pain is described as severe, disturbing and its location is usually fronto-occipital. The conservative treatment of PDPH consists of bed rest, fluid theraphy, analgesics and caffeine. Epidural blood patch is gold standard theraphy but it is an invasive method. The greater occipital nerve (GON) is formed of sensory fibers that originate in the C2 and C3 segments of the spinal cord and it is the main sensory nerve of the occipital region. GON blockage has been used for the treatment of many kinds of headache. The aim of this retrospective study is to present the results of PDPH treated with GON block over 1 year period in our institute. 16 patients who had been diagnosed to have PDPH, and performed GON block after caesarean operations were included in the study. GON blocks were performed as the first treatment directly after diagnose of the PDPH with levobupivacaine and dexamethasone. The mean VAS score of the patients was 8.75 (±0.93) before the block; 3.87 (±1.78) 10min after the block; 1.18 (±2.04) 2h after the block and 2.13 (±1.64) 24h after the block. No adverse effects were observed. Treatment of PDPH with GON block seems to be a minimal invasive, easy and effective method especially after caesarean operations. A GON block may be considered before the application of a blood patch. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.
Jackson, M B; Zhang, S J
1. A theoretical model was developed to investigate action potential propagation in posterior pituitary nerve terminals. This model was then used to evaluate the efficacy of depolarizing and shunting GABA responses on action potential propagation. 2. Experimental data obtained from the posterior pituitary with patch clamp techniques were used to derive empirical expressions for the voltage and time dependence of the nerve terminal Na+ and K+ channels. The essential structure employed here was based on anatomical and cable data from the posterior pituitary, and consisted of a long cylindrical axon (diameter, 0.5 mm) with a large spherical swelling (diameter, 4-21 mm) in the middle. 3. In the absence of an inhibitory conductance, simulated action potentials propagated with high fidelity through the nerve terminal. Swellings could block propagation, but only when sizes exceeded those observed in the posterior pituitary. Adding axonal branches reduced the critical size only slightly. These results suggested that action potentials invade the entire posterior pituitary nerve terminal in the absence of inhibition or depression. 4. The addition of inhibitory conductance to a swelling caused simulated action potentials to fail at the swelling. Depolarizing inhibitory conductances were 1.6 times more effective than shunting inhibitory conductances in blocking propagation. 5. Inhibitory conductances within the range of experimentally observed magnitudes and localized to swellings in the observed range of sizes were too weak to block simulated action potentials. However, twofold enhancement of GABA responses by neurosteroid resulted in currents strong enough to block propagation in realistic swelling sizes. 6. GABA could block simulated propagation without neurosteroid enhancement provided that GABA was present throughout a region in the order of a few hundred micrometres. For this widespread inhibition depolarizing conductance was 2.2 times more effective than shunting
Carteron, Aude; McPartlan, Kerry; Gioeli, Christina; Reid, Emily; Turturro, Matt; Hahn, Barry; Benson, Cynthia; Zhang, Wei
Peripheral sensory feedback plays a crucial role in ensuring correct motor execution throughout hand grasp control. Previous studies utilized local anesthesia to deprive somatosensory feedback in the digits or hand, observations included sensorimotor deficits at both corticospinal and peripheral levels. However, the questions of how the disturbed and intact sensory input integrate and interact with each other to assist the motor program execution, and whether the motor coordination based on motor output variability between affected and non-affected elements (e.g., digits) becomes interfered by the local sensory deficiency, have not been answered. The current study aims to investigate the effect of peripheral deafferentation through digital nerve blocks at selective digits on motor performance and motor coordination in grasp control. Our results suggested that the absence of somatosensory information induced motor deficits in hand grasp control, as evidenced by reduced maximal force production ability in both local and non-local digits, impairment of force and moment control during object lift and hold, and attenuated motor synergies in stabilizing task performance variables, namely the tangential force and moment of force. These findings implied that individual sensory input is shared across all the digits and the disturbed signal from local sensory channel(s) has a more comprehensive impact on the process of the motor output execution in the sensorimotor integration process. Additionally, a feedback control mechanism with a sensation-based component resides in the formation process for the motor covariation structure. PMID:27932964
Chevalier, V; Arbab-Chirani, R; Tea, S H; Roux, M
Bell's palsy is an idiopathic and acute, peripheral nerve palsy resulting in inability to control facial muscles on the affected side because of the involvement of the facial nerve. This study describes a case of Bell's palsy that developed after dental anaesthesia. A 34-year-old pregnant woman at 35 weeks of amenorrhea, with no history of systemic disease, was referred by her dentist for treatment of a mandibular left molar in pulpitis. An inferior alveolar nerve block was made prior to the access cavity preparation. 2h later, the patient felt the onset of a complete paralysis of the left-sided facial muscles. The medical history, the physical examination and the complementary exams led neurologists to the diagnosis of Bell's palsy. The treatment and results of the 1-year follow-up are presented and discussed. Bell's palsy is a rare complication of maxillofacial surgery or dental procedures, the mechanisms of which remain uncertain.
Yu, Bin; He, Miao; Cai, Guang-Yu; Zou, Tian-Xiao; Zhang, Na
Continuous femoral nerve block and fascia iliaca compartment block are 2 traditional anesthesia methods in orthopedic surgeries, but it is controversial which method is better. The objective of this study was to compare the practicality, efficacy, and complications of the 2 modalities in hip replacement surgery in the elderly and to assess the utility of a novel cannula-over-needle set. In this prospective, randomized controlled clinical investigation, 60 elderly patients undergoing hip replacement were randomly assigned to receive either continuous femoral nerve block or continuous fascia iliaca compartment block. After ultrasound-guided nerve block, all patients received general anesthesia for surgery and postoperative analgesia through an indwelling cannula. Single-factor analysis of variance was used to compare the outcome variables between the 2 groups. There was a significant difference between the 2 groups in the mean visual analog scale scores (at rest) at 6 hours after surgery: 1.0 ± 1.3 in the femoral nerve block group vs 0.5 ± 0.8 in the fascia iliaca compartment block group (P < 0.05). The femoral nerve block group had better postoperative analgesia on the medial aspect of the thigh, whereas the fascia iliaca compartment block group had better analgesia on the lateral aspect of the thigh. There were no other significant differences between the groups. Both ultrasound-guided continuous femoral nerve block and fascia iliaca compartment block with the novel cannula-over-needle provide effective anesthesia and postoperative analgesia for elderly hip replacement patients.
Yang, Guangning; Xiao, Zhiying; Wang, Jicheng; Shen, Bing; Roppolo, James R; de Groat, William C; Tai, Changfeng
This study determined if high-frequency biphasic stimulation can induce nerve conduction block that persists after the stimulation is terminated, i.e., post-stimulation block. The frog sciatic nerve-muscle preparation was used in the study. Muscle contraction force induced by low-frequency (0.5 Hz) nerve stimulation was recorded to indicate the occurrence and recovery of nerve block induced by the high-frequency (5 or 10 kHz) biphasic stimulation. Nerve block was observed during high-frequency stimulation and after termination of the stimulation. The recovery from post-stimulation block occurred in two distinct phases. During the first phase, the complete block induced during high-frequency stimulation was maintained. The average maximal duration for the first phase was 107 ± 50 s. During the second phase, the block gradually or abruptly reversed. The duration of both first and second phases was dependent on stimulation intensity and duration but not frequency. Stimulation of higher intensity (1.4-2 times block threshold) and longer duration (5 min) produced the longest period (249 ± 58 s) for a complete recovery. Post-stimulation block can be induced by high-frequency biphasic stimulation, which is important for future investigations of the blocking mechanisms and for optimizing the stimulation parameters or protocols in clinical applications.
Marsan, A; Kirdemir, P; Mamo, D; Casati, A
The aim of this study was to evaluate the onset time of surgical block, recovery of motor function and duration of post-operative analgesia of combined sciatic-femoral nerve block performed with either mepivacaine or prilocaine. With Ethical Committee approval and written informed consent, 30 ASA physical status I-II patients, undergoing elective arthroscopic knee surgery, received a combined sciatic-femoral nerve block with 30 ml of either 2% mepivacaine (n=15) or 1% prilocaine (n=15). An independent observer recorded the onset time of sensory and motor blocks, the need for intraoperative analgesia supplementation, recovery of motor function, and first request of post-operative pain medication. Onset time of nerve block required 15+/-5 min with prilocaine and 12+/-7 min with mepivacaine (p=0.33). No patient required general anesthesia to complete surgery; 3 patients receiving prilocaine (20%) and 2 patients receiving mepivacaine (13%) required 0.1 mg fentanyl intravenously to complete surgery (p=0.99). Recovery of motor function and first request of post-operative pain medication occurred after 238+/-36 min and 259+/-31 min with prilocaine, and 220+/-48 min and 248+/-47 min with mepivacaine (p=0.257 and p=0.43, respectively). Patient satisfaction was good in all studied patients. Prilocaine 1% provides adequate sensory and motor block for arthroscopic knee surgery, with a clinical profile similar to that produced by 2% mepivacaine, and may be a good option for surgical procedures of intermediate duration and not associated with severe postoperative pain.
Kroin, Jeffrey S; Buvanendran, Asokumar; Beck, Daniel R; Topic, Julie E; Watts, Daniel E; Tuman, Kenneth J
Although clonidine is commonly combined with local anesthetics to extend duration of peripheral nerve block, the mechanism by which clonidine potentiates local anesthetic action in vivo is unclear. Male Sprague-Dawley rats received percutaneous injections of 1% lidocaine with/without clonidine or epinephrine into the sciatic notch and duration of sensory blockade was quantified by inhibition of pinprick foot withdrawal. The antagonists prazosin or yohimbine were injected before lidocaine with clonidine or epinephrine to determine the role of alpha-adrenergic receptors. The role of the hyperpolarization-activated cation current (Ih) was evaluated by injecting the current blocker ZD 7288 as well as the current enhancers forskolin and 8-Br-cAMP before lidocaine alone or with 15 micrograms/ml clonidine. Mean duration of sensory block for lidocaine alone was 69 +/- 2 min. Sensory block duration increased monotonically with increasing doses of added clonidine or epinephrine. Preinjection of prazosin but not yohimbine prevented the increase in block duration seen with epinephrine. Neither alpha-adrenergic antagonist attenuated the extended duration of block with clonidine. ZD 7288 extended sensory blockade equivalent to the prolongation observed with clonidine. There was no additive effect when ZD 7288 and clonidine were combined, and a decreased duration of nerve block when either forskolin or 8-Br-cAMP preceded injection of lidocaine with clonidine. The findings indicate that prolongation of duration of in vivo lidocaine nerve blockade by clonidine is not mediated by an alpha-adrenergic mechanism but likely involves the Ih current.
Tempestini Horliana, Anna Carolina Ratto; de Brito, Mayara Aguilar Dias; Perez, Flávio Eduardo Guillin; Simonetti, Maria Prazeres Barbalho; Rocha, Rodney Garcia; Borsatti, Maria Aparecida
To evaluate the duration of the effect of mepivacaine when hyaluronidase is injected immediately prior to the end of pulpal anesthesia. Forty bilateral, symmetrical third molar surgeries were performed in 20 healthy patients. Inferior alveolar nerve block was induced using 2.8 mL 2% mepivacaine with epinephrine. Hyaluronidase (75 turbidity-reducing units) or a placebo was injected 40 minutes after the beginning of pulpar anesthesia (randomized and double-blind trial). The duration of effect in the pulpal and gingival tissues was evaluated by response to painful electrical stimuli applied to the adjacent premolar, and by mechanical stimuli (pin prick) to the vestibular gingiva, respectively. In both tissues, the duration of anesthetic effect with hyaluronidase was longer (P < .01) than with the placebo. Hyaluronidase increases the duration of mepivacaine in inferior alveolar nerve blocks.
Nakamoto, Tatsuo; Kamibayashi, Takahiko
This review outlines the anatomy of the obturator nerve and the indications for obturator nerve block (ONB). Ultrasound-guided ONB techniques and unresolved issues regarding these procedures are also discussed. An ONB is performed to prevent thigh adductor jerk during transurethral resection of bladder tumor, provide analgesia for knee surgery, treat hip pain, and improve persistent hip adductor spasticity. Various ultrasound-guided ONB techniques can be used and can be classified according to whether the approach is distal or proximal. In the distal approach, a transducer is placed at the inguinal crease; the anterior and posterior branches of the nerve are then blocked by two injections of local anesthetic directed toward the interfascial planes where each branch lies. The proximal approach comprises a single injection of local anesthetic into the interfascial plane between the pectineus and obturator externus muscles. Several proximal approaches involving different patient and transducer positions are reported. The proximal approach may be superior for reducing the dose of local anesthetic and providing successful blockade of the obturator nerve, including the hip articular branch, when compared with the distal approach. This hypothesis and any differences between the proximal ONB techniques need to be explored in future studies. PMID:28280738
Springer, Bryan D
The emergence of procedure-specific multimodal pain management regimens that provide effective control of postoperative pain, while markedly reducing the amount of opioid medication required, has been one of the most important advances in hip and knee replacement in recent years. When peripheral nerve blockade first became widely available for inclusion in multimodal regimens, it was viewed as a revolution in the management of postoperative pain. This approach, however, is costly and has some important limitations, including an increased incidence of falls. For many patients, peripheral nerve blocks can now be replaced by a periarticular injection with EXPAREL® (bupivacaine liposome injectable suspension), an extended-release anesthetic infiltrated by the surgeon as part of a multimodal pain regimen. EXPAREL® offers some important clinical and administrative benefits over nerve blocks. Preliminary data from a pilot study comparing the relative effectiveness of EXPAREL® versus sciatic nerve blockade has shown a noticeable reduction in average pain scores at rest with EXPAREL® following both hip and knee arthroplasty, as well as a reduction in the 6- to 12-hour pain score following hip arthroplasty. There was also a significant reduction in opioid use with EXPAREL®, as well as a $411 reduction in the cost of total knee arthroplasty and a $348 reduction in the cost of total hip arthroplasty.
Desjardins, Adrien E.; van der Voort, Marjolein; Roggeveen, Stefan; Lucassen, Gerald; Bierhoff, Walter; Hendriks, Benno H. W.; Brynolf, Marcus; Holmström, Björn
The effectiveness of peripheral nerve blocks is highly dependent on the accuracy at which the needle tip is navigated to the target injection site. Even when electrical stimulation is utilized in combination with ultrasound guidance, determining the proximity of the needle tip to the target region close to the nerve can be challenging. Optical reflectance spectroscopy could provide additional information about tissues that is complementary to these navigation methods. We demonstrate a novel needle stylet for acquiring spectra from tissue at the tip of a commercial 20-gauge needle. The stylet has integrated optical fibers that deliver broadband light to tissue and receive scattered light. Two spectrometers resolve the light that is received from tissue across the wavelength range of 500-1600 nm. In our pilot study, measurements are acquired from a postmortem dissection of the brachial plexus of a swine. Clear differences are observed between spectra acquired from nerves and those acquired from adjacent tissue structures. We conclude that spectra acquired with the stylet have the potential to increase the accuracy with which peripheral nerve blocks are performed.
Fernández Martín, M T; López Álvarez, S; Mozo Herrera, G; Platero Burgos, J J
Laparoscopic cholecystectomy has become the standard treatment for gallbladder diseases. However, there are still some patients for whom conversion to open surgery is required. This surgery can produce significant post-operative pain. Opioids drugs have traditionally been used to treat this pain, but side effects have led to seeking alternatives (plexus, nerve or fascia blocks or wound). The cases are presented of 4 patients subjected to ultrasound-guided intercostal branches blocks in the mid-axillary line from T6 to T12 with levobupivacaine as an analgesic alternative in open surgery of gallbladder, with satisfactory results.
Xiao, Peng; Zhu, Xu; Wu, Xuejian
This paper aimed to discuss the curative effect and safety of curing intercostal neuralgia through paravertebral nerve block combined with pregabalin. 90 cases of patients diagnosed as intercostal neuralgia were taken as research object. Random number method was used to divide the patients that is conforming to the inclusion criteria and exclusion criteria into 3 groups. 30 cases was in group A (oral lyrica), 30 cases was in group B (paravertebral block only) and 30 cases was in group C (paravertebral block combined with pregabalin). The clinical effect and safety of three groups was compared. The result showed that: visual analogue scale (VAS) and quality of sleep (QS) of three groups of patients after treatment all decreased obviously; group A had slow work, large amount of dosage and many adverse effects; group B had quick work, but the improvement on pain and sleep was not satisfactory; the curative effect of group C was higher than group A and B (p<0.05); 3 groups all had adverse effect, among which group C had the least adverse effect. It can be concluded that paravertebral nerve block combined with pregabalin for curing intercostal neuralgia was superior than single use of pregabalin or paravertebral block and that is worth to promote.
Murthy, Varsha; V, Yuvraj; Nair, Preeti P; Thomas, Shaji; Krishna, Akash; Cyriac, Sumeeth
When gag reflex becomes abnormally active, it poses difficulty for the prosthodontists, as it hinders the process of fixed partial denture construction beginning with tooth preparation till impression making. In this case-report, the authors used a nerve block technique which is popular among anaesthetist and otolaryngologist, but is being applied in the field of prosthodontics for the first time, to tide over the difficulty. PMID:22679052
Phantom Limb Pain With Ambulatory Continuous...TYPE Annual 3. DATES COVERED 26 Dec 2013 – 25 Dec 2014 4. TITLE AND SUBTITLE Treating Intractable Post-Amputation Phantom Limb Pain With Ambulatory...continuous peripheral nerve block (CPNB) is an effective treatment for intractable phantom limb pain
Velasco, Ignacio; Soto, Reinaldo
Background: Dental procedures in the maxilla typically require multiple injections and may inadvertently anesthetize facial structures and affect the smile line. To minimize these inconveniences and reduce the number of total injections, a relatively new injection technique has been proposed for maxillary procedures, the anterior and middle superior alveolar (AMSA) nerve block, which achieves pulpal anesthesia from the central incisor to second premolar through palatal approach with a single injection. The purpose of this article is to provide background information on the anterior and middle superior alveolar nerve block and demonstrate its success rates of pulpal anesthesia using the conventional syringe. Materials and Methods: Thirty Caucasian patients (16 men and 14 women) with an average age of 22 years-old, belonging to the School of Dentistry of Los Andes University, were selected. All the patients received an AMSA nerve block on one side of the maxilla using the conventional syringe, 1 ml of lidocaine 2% with epinephrine 1:100.000 was injected to all the patients. Results: The AMSA nerve block obtained a 66% anesthetic success in the second premolar, 40% in the first premolar, 60% in the canine, 23.3% in the lateral incisor, and 16.7% in the central incisor. Conclusions: Because of the unpredictable anesthetic success of the experimental teeth and variable anesthesia duration, the technique is disadvantageous for clinical application as the first choice, counting with other techniques that have greater efficacy in the maxilla. Although, anesthetizing the teeth without numbing the facial muscles may be useful in restorative dentistry. PMID:23559916
Comerci, Andrew W; Maller, Steven C; Townsend, Richard D; Teepe, John D; Vandewalle, Kraig S
The purpose of this double-blind, split-mouth, randomized human clinical study was to evaluate the effectiveness of a new sodium bicarbonate local anesthetic buffering device (Onset) in reducing pain associated with dental injections. Twenty patients were given bilateral inferior alveolar (IA) and long buccal (LB) nerve block injections and asked to quantify the pain experienced during injection on a visual analog scale (0, no pain; 10, worst possible pain). One side of the mouth received standard-of-care injections of 2% lidocaine with 1:100,000 epinephrine. On the opposite side, after the buffering device was used to mix the components within the anesthetic carpule, patients received injections of 2% lidocaine with 1:100,000 epinephrine buffered 9:1 with 8.4% sodium bicarbonate. The mean pain scores were 2.7 (SD, 1.3) for buffered and 2.7 (SD, 1.9) for unbuffered IA injections. The mean pain scores were 2.0 (SD, 1.4) for buffered and 2.7 (SD, 1.8) for unbuffered LB injections. The data were analyzed with a paired t test (α = 0.05), and no statistically significant difference was found between groups for IA (P = 0.94) or LB (P = 0.17) nerve block injections. In this study of patients receiving common dental nerve block injections, local anesthetic buffering technology did not significantly lessen pain compared to that experienced during a standard unbuffered injection.
de Souza Melo, Marcelo Rodrigo; Sabey, Mark Jon Santana; Lima, Carla Juliane; de Almeida Souza, Liane Maciel; Groppo, Francisco Carlos
This randomized double-blind crossover trial investigated the discomfort associated with 2 injection speeds, low (60 seconds) and slow (100 seconds), during inferior alveolar nerve block by using 1.8 mL of 2% lidocaine with 1 : 100,000 epinephrine. Three phases were considered: (a) mucosa perforation, (b) needle insertion, and (c) solution injection. Thirty-two healthy adult volunteers needing bilateral inferior alveolar nerve blocks at least 1 week apart were enrolled in the present study. The anesthetic procedure discomfort was recorded by volunteers on a 10-cm visual analog scale in each phase for both injection speeds. Comparison between the 2 anesthesia speeds in each phase was performed by paired t test. Results showed no statistically significant difference between injection speeds regarding perforation (P = .1016), needle placement (P = .0584), or speed injection (P = .1806). The discomfort in all phases was considered low. We concluded that the 2 injection speeds tested did not affect the volunteers' pain perception during inferior alveolar nerve blocks. PMID:26398126
Ortega Ramírez, Moisés; Linares Segovia, Benigno; García Cuevas, Marco Antonio; Sánchez Romero, Jorge Luis; Botello Buenrostro, Illich; Amador Licona, Norma; Guízar Mendoza, Juan Manuel; Guerrero Romero, Jesús Francisco; Vázquez Zárate, Víctor Manuel
Aim of the Study. To compare the effect of glossopharyngeal nerve block with topical anesthesia on the tolerance of patients to upper gastrointestinal endoscopy. Methods. We performed a clinical trial in one hundred patients undergoing upper gastrointestinal endoscopy. Subjects were randomly assigned to one of the following two groups: (1) treatment with bilateral glossopharyngeal nerve block (GFNB) and intravenous midazolam or (2) treatment with topical anesthetic (TASS) and intravenous midazolam. We evaluated sedation, tolerance to the procedure, hemodynamic stability, and adverse symptoms. Results. We studied 46 men and 54 women, from 17 to 78 years of age. The procedure was reported without discomfort in 48 patients (88%) in the GFNB group and 32 (64%) in the TAAS group; 6 patients (12%) in GFNB group and 18 (36%) in TAAS group reported the procedure as little discomfort (χ2 = 3.95, P = 0.04). There was no difference in frequency of nausea (4% in both groups) and retching, 4% versus 8% for GFNB and TASS group, respectively (P = 0.55). Conclusions. The use of glossopharyngeal nerve block provides greater comfort and tolerance to the patient undergoing upper gastrointestinal endoscopy. It also reduces the need for sedation. PMID:23533386
Ortega Ramírez, Moisés; Linares Segovia, Benigno; García Cuevas, Marco Antonio; Sánchez Romero, Jorge Luis; Botello Buenrostro, Illich; Amador Licona, Norma; Guízar Mendoza, Juan Manuel; Guerrero Romero, Jesús Francisco; Vázquez Zárate, Víctor Manuel
Aim of the Study. To compare the effect of glossopharyngeal nerve block with topical anesthesia on the tolerance of patients to upper gastrointestinal endoscopy. Methods. We performed a clinical trial in one hundred patients undergoing upper gastrointestinal endoscopy. Subjects were randomly assigned to one of the following two groups: (1) treatment with bilateral glossopharyngeal nerve block (GFNB) and intravenous midazolam or (2) treatment with topical anesthetic (TASS) and intravenous midazolam. We evaluated sedation, tolerance to the procedure, hemodynamic stability, and adverse symptoms. Results. We studied 46 men and 54 women, from 17 to 78 years of age. The procedure was reported without discomfort in 48 patients (88%) in the GFNB group and 32 (64%) in the TAAS group; 6 patients (12%) in GFNB group and 18 (36%) in TAAS group reported the procedure as little discomfort (χ (2) = 3.95, P = 0.04). There was no difference in frequency of nausea (4% in both groups) and retching, 4% versus 8% for GFNB and TASS group, respectively (P = 0.55). Conclusions. The use of glossopharyngeal nerve block provides greater comfort and tolerance to the patient undergoing upper gastrointestinal endoscopy. It also reduces the need for sedation.
Moon, Young Eun; Choi, Jung Hyun; Park, Hue Jung; Park, Ji Hye; Kim, Ji Hyun
Neuropathic pain includes postherpetic neuralgia (PHN), painful diabetic neuropathy (PDN), and trigeminal neuralgia, and so on. Although various drugs have been tried to treat neuropathic pain, the effectiveness of the drugs sometimes may be limited for chronic intractable neuropathic pain, especially when they cannot be used at an adequate dose, due to undesirable severe side effects and the underlying disease itself. Botulinum toxin type A (BoNT-A) has been known for its analgesic effect in various pain conditions. Nevertheless, there are no data of nerve block in PHN and PDN. Here, we report two patients successfully treated with ultrasound-guided peripheral nerve block using BoNT-A for intractable PHN and PDN. One patient had PHN on the left upper extremity and the other patient had PDN on a lower extremity. Due to side effects of drugs, escalation of the drug dose could not be made. We injected 50 Botox units (BOTOX®, Allergan Inc., Irvine, CA, USA) into brachial plexus and lumbar plexus, respectively, under ultrasound. Their pain was significantly decreased for about 4–5 months. Ultrasound-guided nerve block with BoNT-A may be an effective analgesic modality in a chronic intractable neuropathic pain especially when conventional treatment failed to achieve adequate pain relief. PMID:26761032
Shah, Ajul; Rowlands, Megan; Krishnan, Naveen; Patel, Anup; Ott-Young, Anke
Traditionally, narcotics have been used for analgesia after breast surgery. However, these agents have unpleasant side effects. Intercostal nerve blockade is an alternative technique to improve postoperative pain. In this study, the authors investigate outcomes in patients who receive thoracic intercostal nerve blocks for implant-based breast reconstruction. A retrospective chart review was performed. The operative technique for breast reconstruction and administration of nerve blocks is detailed. Demographic factors, length of stay, and complications were recorded. The consumption of morphine, Valium, Zofran, and oxycodone was recorded. Data sets for patients receiving thoracic intercostal nerve blocks were compared against those that did not. One hundred thirty-two patients were included. For patients undergoing bilateral reconstruction with nerve blocks, there was a significant reduction in length of stay (1.87 days versus 2.32 days; p = 0.001), consumption of intravenous morphine (5.15 mg versus 12.68 mg; p = 0.041) and Valium (22.24 mg versus 31.13 mg; p = 0.026). For patients undergoing unilateral reconstruction with nerve blocks, there was a significant reduction in consumption of intravenous morphine (2.80 mg versus 8.17 mg; p = 0.007). For bilateral reconstruction with intercostal nerve block, cost savings equaled $2873.14 per patient. For unilateral reconstruction with intercostal nerve block, cost savings equaled $1532.34 per patient. The authors' data demonstrate a reduction in the consumption of pain medication, in the hospital length of stay, and in hospital costs for patients receiving intercostal nerve blocks at the time of pectoralis elevation for implant-based breast reconstruction. Therapeutic, III.
Zhang, Zhaocun; Lyon, Timothy D.; Kadow, Brian T.; Shen, Bing; Wang, Jicheng; Lee, Andy; Kang, Audry; Roppolo, James R.; de Groat, William C.
This study aimed at understanding thermal effects on nerve conduction and developing new methods to produce a reversible thermal block of axonal conduction in mammalian myelinated nerves. In 13 cats under α-chloralose anesthesia, conduction block of pudendal nerves (n = 20) by cooling (5–30°C) or heating (42–54°C) a small segment (9 mm) of the nerve was monitored by the urethral striated muscle contractions and increases in intraurethral pressure induced by intermittent (5 s on and 20 s off) electrical stimulation (50 Hz, 0.2 ms) of the nerve. Cold block was observed at 5–15°C while heat block occurred at 50–54°C. A complete cold block up to 10 min was fully reversible, but a complete heat block was only reversible when the heating duration was less than 1.3 ± 0.1 min. A brief (<1 min) reversible complete heat block at 50–54°C or 15 min of nonblock mild heating at 46–48°C significantly increased the cold block temperature to 15–30°C. The effect of heating on cold block fully reversed within ∼40 min. This study discovered a novel method to block mammalian myelinated nerves at 15–30°C, providing the possibility to develop an implantable device to block axonal conduction and treat many chronic disorders. The effect of heating on cold block is of considerable interest because it raises many basic scientific questions that may help reveal the mechanisms underlying cold or heat block of axonal conduction. PMID:26740534
Khalil, Nathalie; Chauvière, Claudie; Le Chapelain, Loïc; Guesdon, Hélène; Speyer, Elodie; Bouaziz, Hervé; Mainard, Didier; Beis, Jean-Marie; Paysant, Jean
The aim of this study was to analyze the displacements of center of pressure (COP) using an in-shoe recording system (F-Scan) before and after motor nerve block and neurotomy of the tibial nerve in spastic equinovarus foot. Thirty-nine patients (age 45 ± 15 yr) underwent a motor nerve block; 16 (age 38 ± 15.2 yr) had tibial neurotomy, combined with tendinous surgery (n = 9). The displacement of the COP (anteroposterior [AP], lateral deviation [LD], posterior margin [PM]) was compared between paretic and nonparetic limbs before and after block and surgery. At baseline, the nonparetic limb had a higher AP (17.3 vs 12.3 cm, p < 0.001) and LD (4.0 vs 3.3 cm, p = 0.001) and a smaller PM (2.9 vs 4.7 cm, p = 0.001). For the paretic limb, a significant increase of AP was observed after block (13.5 vs 12.3 cm, p = 0.02) and after surgery (13.7 vs 12.3 cm, p = 0.03). A significant decrease of PM was observed after surgery (4.5 vs 3.3 cm, p < 0.001) with no more difference between two limbs (2.8 vs 3.3 cm; p = 0.44). This study shows that the F-Scan system can be used to quantify impairments and be useful to evaluate the effects of treatment for spastic foot. It suggests that changes in AP displacement following block may predict the effects of neurotomy.
Watts, S A; Sharma, D J
Peripheral nerve blockade is gaining popularity as an analgesic option for both upper or lower limb surgery. Published evidence supports the improved efficacy of regional techniques when compared to conventional opioid analgesia. The incidence of neurological deficit after surgery associated with peripheral nerve block is unclear. This paper reports on neurological outcomes occurring after 1065 consecutive peripheral nerve blocks over a one-year period from a single institution. All patients receiving peripheral nerve blocks for surgery were prospectively followed for up to 12 months to determine the incidence and probable cause of any persistent neurological deficit. Formal independent neurological review and testing was undertaken as indicated. Thirteen patients reported symptoms that warranted further investigation. A variety of probable causes were identified, with peripheral nerve block being implicated in two cases (one resolved at nine months and one remaining persistent). Overall incidence of block-related neuropathy was 0.22%. Persistent postoperative neuropathy is a rare but serious complication of surgery associated with peripheral nerve block. Formal follow-up of all such blocks is recommended to assess causality and allow for early intervention.
... then monitoring how the patient responds to the injection, the doctor can often use this information to help determine the cause or source of the pain as well as guide further treatment. top of page How ...
Sousa, A.M.; Ashmawi, H.A.; Costa, L.S.; Posso, I.P.; Slullitel, A.
Local anesthetic efficacy of tramadol has been reported following intradermal application. Our aim was to investigate the effect of perineural tramadol as the sole analgesic in two pain models. Male Wistar rats (280-380 g; N = 5/group) were used in these experiments. A neurostimulation-guided sciatic nerve block was performed and 2% lidocaine or tramadol (1.25 and 5 mg) was perineurally injected in two different animal pain models. In the flinching behavior test, the number of flinches was evaluated and in the plantar incision model, mechanical and heat thresholds were measured. Motor effects of lidocaine and tramadol were quantified and a motor block score elaborated. Tramadol, 1.25 mg, completely blocked the first and reduced the second phase of the flinching behavior test. In the plantar incision model, tramadol (1.25 mg) increased both paw withdrawal latency in response to radiant heat (8.3 ± 1.1, 12.7 ± 1.8, 8.4 ± 0.8, and 11.1 ± 3.3 s) and mechanical threshold in response to von Frey filaments (459 ± 82.8, 447.5 ± 91.7, 320.1 ± 120, 126.43 ± 92.8 mN) at 5, 15, 30, and 60 min, respectively. Sham block or contralateral sciatic nerve block did not differ from perineural saline injection throughout the study in either model. The effect of tramadol was not antagonized by intraperitoneal naloxone. High dose tramadol (5 mg) blocked motor function as well as 2% lidocaine. In conclusion, tramadol blocks nociception and motor function in vivo similar to local anesthetics. PMID:22183244
YaDeau, Jacques T.; Paroli, Leonardo; Fields, Kara G.; Kahn, Richard L.; LaSala, Vincent R.; Jules-Elysee, Kethy M.; Kim, David H.; Haskins, Stephen C.; Hedden, Jacob; Goon, Amanda; Roberts, Matthew M.; Levine, David S.
Background and Objectives Sciatic nerve block provides analgesia after foot and ankle surgery, but block duration may be insufficient. We hypothesized that perineural dexamethasone and buprenorphine would reduce pain scores at 24 hours. Methods Ninety patients received ultrasound-guided sciatic (25 mL 0.25% bupivacaine) and adductor canal (10 mL 0.25% bupivacaine) blockade, with random assignment into 3 groups (30 patients per group): control blocks + intravenous dexamethasone (4 mg) (control); control blocks + intravenous buprenorphine (150 mcg) + intravenous dexamethasone (intravenous buprenorphine); nerve blocks containing buprenorphine + dexamethasone (perineural). Patients received mepivacaine neuraxial anesthesia and postoperative oxycodone / acetaminophen, meloxicam, pregabalin, and ondansetron. Patients and assessors were blinded to group assignment. The primary outcome was pain with movement at 24 hours. Results There was no difference in pain with movement at 24 hours (median score 0). However, the perineural group had longer block duration vs control (45.6 vs 30.0 hr). Perineural patients had lower scores for “worst pain” vs control (median 0 vs 2). Both intravenous buprenorphine and perineural groups were less likely to use opioids on the day after surgery, vs control (28.6%, 28.6%, 60.7%, respectively). Nausea after intravenous buprenorphine (but not perineural buprenorphine) was severe, frequent, and bothersome. Conclusions Pain scores were very low at 24 hours after surgery in the context of multimodal analgesia and were not improved by additives. However, perineural buprenorphine and dexamethasone prolonged block duration, reduced the worst pain experienced, and reduced opioid use. Intravenous buprenorphine caused troubling nausea and vomiting. Future research is needed to confirm and extend these observations. PMID:25974277
Brazhe, A. R.; Maksimov, G. V.; Mosekilde, E.; Sosnovtseva, O. V.
The myelinated nerve fibre is formed by an axon and Schwann cells or oligodendrocytes that sheath the axon by winding around it in tight myelin layers. Repetitive stimulation of a fibre is known to result in accumulation of extracellular potassium ions, especially between the axon and the myelin. Uptake of potassium leads to Schwann cell swelling and myelin restructuring that impacts the electrical properties of the myelin. In order to further understand the dynamic interaction that takes place between the myelin and the axon, we have modelled submyelin potassium accumulation and related changes in myelin resistance during prolonged high-frequency stimulation. We predict that potassium-mediated decrease in myelin resistance leads to a functional excitation block with various patterns of altered spike trains. The patterns are found to depend on stimulation frequency and amplitude and to range from no block (less than 100 Hz) to a complete block (greater than 500 Hz). The transitional patterns include intermittent periodic block with interleaved spiking and non-spiking intervals of different relative duration as well as an unstable regime with chaotic switching between the spiking and non-spiking states. Intermittent conduction blocks are accompanied by oscillations of extracellular potassium. The mechanism of conductance block based on myelin restructuring complements the already known and modelled block via hyperpolarization mediated by the axonal sodium pump and potassium depolarization. PMID:22419976
Honey, R John D'A; Ghiculete, Daniela; Ray, A Andrew; Pace, Kenneth T
The optimal method of pain control after percutaneous nephrolithotomy (PCNL) remains controversial. We sought to determine whether intercostal nerve block with bupivicaine provided superior pain control, when compared with placebo, with a lower need for narcotics and improved health-related quality of life (HRQL) in the immediate postoperative period. Sixty-three patients were randomized to receive intercostal blockade with either 20 mL of 0.5% bupivacaine with epinephrine or 20 mL physiologic saline. All patients received intravenous narcotic patient-controlled analgesia (PCA) postoperatively. Data were collected on stone parameters, demographics, analgesic usage, length of stay, and HRQL as assessed by the Postoperative Recovery Scale. The mean age was 47.7±1.2 years; mean body mass index was 28.0±5.0 kg/m(2); mean stone diameter was 29.2±15.8 mm. Within the first 3 to 6 hours after surgery, there was a significant reduction in narcotic use for the group receiving intercostal nerve blockade with bupivacaine compared with placebo. At 3 hours, narcotic use was 2.4±3.1 mg vs 4.3±3.8 mg morphine equivalents (P=0.034), and within 6 hours of surgery, narcotic use was 5.9±6.1 mg vs 8.8±7.4 mg (P=0.096). Durable improvement in HRQL was also observed in patients receiving intercostal nerve blockade with bupivacaine compared with placebo (P=0.034). No complications were attributable to the intercostal nerve blocks in either group. Intercostal blockade with bupivacaine significantly improves both pain control and HRQL in the early postoperative period. The effectiveness of bupivacaine disappears within 6 hours of surgery, after which narcotic use becomes indistinguishable. Intercostal nerve blockade is an easy, safe, and inexpensive method that can be used to optimize pain control after PCNL.
Lee, Jae Jun; Kim, Do-Young; Hwang, Jung-Taek; Lee, Sang-Soo; Hwang, Sung Mi; Kim, Gi Ho; Jo, Yoon-Geol
The aim of this study was to compare the results of ultrasonographically guided axillary nerve block (ANB) combined with suprascapular nerve block (SSNB) with those of SSNB alone on postoperative pain and satisfaction within the first 48 hours after arthroscopic rotator cuff repair. Forty-two patients with rotator cuff tears who had undergone arthroscopic rotator cuff repair were enrolled in this study. Among them, 21 patients were randomly allocated to group 1 and received both SSNB and ANB with 10 mL ropivacaine. The other 21 patients were allocated to group 2 and received SSNB with 10 mL 0.75% ropivacaine and ANB with 10 mL saline. Visual analog scale (VAS) pain score, patient satisfaction (SAT), and lateral pain index (LPI) was checked at 1, 3, 6, 12, 18, 24, 36, and 48 hours postoperatively. Group 1 showed a significantly lower mean VAS score at postoperative 1, 3, 6, 12, 18, and 24 hours compared with group 2 (5.1 < 7.6, 4.4 < 6.3, 3.7 < 5.3, 3.2 < 4.5, 2.7 < 4.0, and 2.7 < 3.4, respectively). A significantly high mean SAT and low mean LPI was observed in group 1 at postoperative 1, 3, 6, 12, 18, 24, and 36 hours (4.9 > 2.4, 5.9 > 3.7, 6.3 > 5.0, 6.8 > 5.7, 7.3 > 6.2, 7.5 > 6.6, and 7.7 > 7.0, respectively), (1.1 < 3.0, 0.8 < 2.5, 0.7 < 2.0, 0.7 < 1.6, 0.6 < 1.3, 0.6 < 1.0, and 0.4 < 0.7, respectively). The frequency of rebound pain decreased in group 1 compared with group 2 (P = .032). In addition, rebound phenomenon showed a correlation with ANB on univariate logistic regression (P = .034; odds ratio, 0.246). Ultrasonographically guided ANB combined with SSNB in arthroscopic rotator cuff repair showed an improved mean VAS in the first 24 hours after surgery compared with SSNB alone. The mean SAT and LPI of the combined blocks were better than those of the single block within the first 36 hours. Ultrasonographically guided ANB combined with SSNB also decreased the rebound phenomenon. Level I, randomized controlled trial. Copyright © 2014
Krodel, David J; Belvis, Dawn; Suresh, Santhanam
We describe the use of inferior alveolar nerve blocks (IANBs) for postoperative pain control for a neonate undergoing mandibular distraction and osteotomies. In this case, bilateral IANBs were effective in keeping low pain scores as assessed on the neonatal infant pain scale (NIPS) and the amount of opioid and adjuvant analgesics used. The blocks were assessed to have lasted approximately 24 h making serial blocks for pain control logistically feasible. Additionally, pain control was improved throughout the period of distractor advancement (approximately 7 days). We propose the routine use of this regional technique for improved pain control after this procedure in neonates and suggest that improved pain control may facilitate earlier extubation in this challenging population. © 2014 John Wiley & Sons Ltd.
Ringkamp, M.; Schepers, R. J.; Shimada, S.G.; Johanek, L.M.; Hartke, T.V.; Borzan, J.; Shim, B.; LaMotte, R.H.; Meyer, R.A.
Despite its clinical importance, the underlying neural mechanisms of itch sensation are poorly understood. In many diseases, pruritus is not effectively treated with antihistamines, indicating the involvement of non-histaminergic mechanisms. To investigate the role of small myelinated afferents in non-histaminergic itch, we tested, in psychophysical studies in humans, the effect of a differential nerve block on itch produced by intradermal insertion of spicules from the pods of a cowhage plant (Mucuna pruriens). Electrophysiological experiments in anesthetized monkey were used to investigate the responsiveness of cutaneous, nociceptive, myelinated afferents to different chemical stimuli (cowhage spicules, histamine, capsaicin). Our results provide several lines of evidence for an important role of myelinated fibers in cowhage-induced itch: 1) a selective conduction block in myelinated fibers substantially reduces itch in a sub-group of subjects with A-fiber dominated itch, 2) the time course of itch sensation differs between subjects with A-fiber versus C-fiber dominated itch, 3) cowhage activates a subpopulation of myelinated and unmyelinated afferents in monkey, 4) the time course of the response to cowhage is different in myelinated and unmyelinated fibers, 5) the time of peak itch sensation for subjects with A-fiber dominated itch matches the time for peak response in myelinated fibers, and 6) the time for peak itch sensation for subjects with C-fiber dominated itch matches the time for the peak response in unmyelinated fibers. These findings demonstrate that activity in nociceptive, myelinated afferents contributes to cowhage-induced sensations, and that non-histaminergic itch is mediated through activity in both unmyelinated and myelinated afferents. PMID:22016517
Ringkamp, Matthias; Schepers, Raf J; Shimada, Steven G; Johanek, Lisa M; Hartke, Timothy V; Borzan, Jasenka; Shim, Beom; LaMotte, Robert H; Meyer, Richard A
Despite its clinical importance, the underlying neural mechanisms of itch sensation are poorly understood. In many diseases, pruritus is not effectively treated with antihistamines, indicating the involvement of nonhistaminergic mechanisms. To investigate the role of small myelinated afferents in nonhistaminergic itch, we tested, in psychophysical studies in humans, the effect of a differential nerve block on itch produced by intradermal insertion of spicules from the pods of a cowhage plant (Mucuna pruriens). Electrophysiological experiments in anesthetized monkey were used to investigate the responsiveness of cutaneous, nociceptive, myelinated afferents to different chemical stimuli (cowhage spicules, histamine, capsaicin). Our results provide several lines of evidence for an important role of myelinated fibers in cowhage-induced itch: (1) a selective conduction block in myelinated fibers substantially reduces itch in a subgroup of subjects with A-fiber-dominated itch, (2) the time course of itch sensation differs between subjects with A-fiber- versus C-fiber-dominated itch, (3) cowhage activates a subpopulation of myelinated and unmyelinated afferents in monkey, (4) the time course of the response to cowhage is different in myelinated and unmyelinated fibers, (5) the time of peak itch sensation for subjects with A-fiber-dominated itch matches the time for peak response in myelinated fibers, and (6) the time for peak itch sensation for subjects with C-fiber-dominated itch matches the time for the peak response in unmyelinated fibers. These findings demonstrate that activity in nociceptive, myelinated afferents contributes to cowhage-induced sensations, and that nonhistaminergic itch is mediated through activity in both unmyelinated and myelinated afferents.
Stav, Anatoli; Reytman, Leonid; Stav, Michael-Yohay; Troitsa, Anton; Kirshon, Mark; Alfici, Ricardo; Dudkiewicz, Mickey; Sternberg, Ahud
Objectives We hypothesized that preoperative (pre-op) ultrasound (US)-guided posterior transversus abdominis plane block (TAP) and US-guided ilioinguinal and iliohypogastric nerve block (ILI+IHG) will produce a comparable analgesia after Lichtenstein patch tension-free method of open inguinal hernia repair in adult men. The genital branch of the genitofemoral nerve will be blocked separately. Methods This is a prospective, randomized, controlled, and observer-blinded clinical study. A total of 166 adult men were randomly assigned to one of three groups: a pre-op TAP group, a pre-op ILI+IHG group, and a control group. An intraoperative block of the genital branch of the genitofemoral nerve was performed in all patients in all three groups, followed by postoperative patient-controlled intravenous analgesia with morphine. The pain intensity and morphine consumption immediately after surgery and during the 24 hours after surgery were compared between the groups. Results A total of 149 patients completed the study protocol. The intensity of pain immediately after surgery and morphine consumption were similar in the two “block” groups; however, they were significantly decreased compared with the control group. During the 24 hours after surgery, morphine consumption in the ILI+IHG group decreased compared with the TAP group, as well as in each “block” group versus the control group. Twenty-four hours after surgery, all evaluated parameters were similar. Conclusion Ultrasound-guided ILI+IHG provided better pain control than US-guided posterior TAP following the Lichtenstein patch tension-free method of open inguinal hernia repair in men during 24 hours after surgery. (ClinicalTrials.gov number: NCT01429480.) PMID:27487311
Maga, Joni; Missair, Andres; Visan, Alex; Kaplan, Lee; Gutierrez, Juan F; Jain, Annika R; Gebhard, Ralf E
Ultrasound-guided interscalene brachial plexus blocks are commonly used to provide anesthesia for the shoulder and proximal upper extremity. Some reviews identify a sheath that envelops the brachial plexus as a potential tissue plane target, and current editorials in the literature highlight the need to establish precise and reproducible injection targets under ultrasound guidance. We hypothesize that an injection of a local anesthetic inside the brachial plexus sheath during ultrasound-guided interscalene nerve blocks will result in enhanced procedure success and provide a consistent tissue plane target for this approach with a reproducible and characteristic local anesthetic spread pattern. Sixty patients scheduled for shoulder surgery with a preoperative interscalene block for postoperative pain management were enrolled in this prospective randomized observer-blinded study. Each patient was randomly assigned to receive a single-shot interscalene block either inside or outside the brachial plexus sheath. The rate of complete motor and sensory blocks of the axillary nerve territory 10 minutes after local anesthetic injection for the inside group was 70% versus 37% for the outside group (P < .05). At all measurement intervals beyond 10 minutes, however, neither group showed a statistically significant difference in complete sensory blockade. The incidence rates of transient paresthesia during needle passage were 6.7% for the outside group and 96.7% for the inside group (P < .05). Except for faster onset, this prospective randomized trial did not find any advantages to performing an interscalene block inside the brachial plexus sheath. There was a higher incidence of transient paresthesia when injections were performed inside compared to outside the sheath. © 2016 by the American Institute of Ultrasound in Medicine.
Park, Chang Kyu; Kim, Min Ki; Park, Bong Jin; Choi, Seok Geun; Lim, Young Jin; Kim, Tae Sung
Objective The incidence of spinal treatment, including nerve block, radiofrequency neurotomy, instrumented fusions, is increasing, and progressively involves patients of age 65 and older. Treatment of the geriatric patients is often a difficult challenge for the spine surgeon. General health, sociofamilial and mental condition of the patients as well as the treatment techniques and postoperative management are to be accurately evaluated and planned. We tried to compare three treatment methods of spinal stenosis for geriatric patient in single institution. Methods The cases of treatment methods in spinal stenosis over than 65 years old were analyzed. The numbers of patients were 371 underwent nerve block, radiofrequency neurotomy, instrumented fusions from January 2009 to December 2012 (nerve block: 253, radiofrequency neurotomy: 56, instrumented fusions: 62). The authors reviewed medical records, operative findings and postoperative clinical results, retrospectively. Simple X-ray were evaluated and clinical outcome was measured by Odom's criteria at 1 month after procedures. Results We were observed excellent and good results in 162 (64%) patients with nerve block, 40 (71%) patient with radIofrequency neurotomy, 46 (74%) patient with spinal surgery. Poor results were 20 (8%) patients in nerve block, 2 (3%) patients in radiofrequency neurotomy, 3 (5%) patient in spinal surgery. Conclusion We reviewed literatures and analyzed three treatment methods of spinal stenosis for geriatric patients. Although the long term outcome of surgical treatment was most favorable, radiofrequency neurotomy and nerve block can be considered for the secondary management of elderly lumbar spinals stenosis patients. PMID:25346752
Park, Chang Kyu; Kim, Sung Bum; Kim, Min Ki; Park, Bong Jin; Choi, Seok Geun; Lim, Young Jin; Kim, Tae Sung
The incidence of spinal treatment, including nerve block, radiofrequency neurotomy, instrumented fusions, is increasing, and progressively involves patients of age 65 and older. Treatment of the geriatric patients is often a difficult challenge for the spine surgeon. General health, sociofamilial and mental condition of the patients as well as the treatment techniques and postoperative management are to be accurately evaluated and planned. We tried to compare three treatment methods of spinal stenosis for geriatric patient in single institution. The cases of treatment methods in spinal stenosis over than 65 years old were analyzed. The numbers of patients were 371 underwent nerve block, radiofrequency neurotomy, instrumented fusions from January 2009 to December 2012 (nerve block: 253, radiofrequency neurotomy: 56, instrumented fusions: 62). The authors reviewed medical records, operative findings and postoperative clinical results, retrospectively. Simple X-ray were evaluated and clinical outcome was measured by Odom's criteria at 1 month after procedures. We were observed excellent and good results in 162 (64%) patients with nerve block, 40 (71%) patient with radIofrequency neurotomy, 46 (74%) patient with spinal surgery. Poor results were 20 (8%) patients in nerve block, 2 (3%) patients in radiofrequency neurotomy, 3 (5%) patient in spinal surgery. We reviewed literatures and analyzed three treatment methods of spinal stenosis for geriatric patients. Although the long term outcome of surgical treatment was most favorable, radiofrequency neurotomy and nerve block can be considered for the secondary management of elderly lumbar spinals stenosis patients.
Diagnostic nerve blocks: The popularity of neural blockade as a diagnostic tool in painful conditions, especially in the spine, is due to features like the unspecific character of spinal pain, the irrelevance of radiological findings and the purely subjective character of pain. It is said that apart from specific causes of pain and clear radicular involvement with obvious neurological deficits and corresponding findings of a prolapsed disc in MRI or CT pictures, a diagnosis of the anatomical cause of the pain can only be established if invasive tests are used . These include zygapophyseal joint blocks, sacroiliacal joint blocks, disc stimulation and nerve root blocks. Under controlled conditions, it has been shown that among patients with chronic nonradicular low back pain, some 10-15% have zygapophyseal joint pain , some 15-20% have sacroiliacal joint pain [36, 59] and 40% have pain from internal disc disruption . The diagnostic use of neural blockade rests on three premises. First, pathology causing pain is located in an exact peripheral location, and impulses from this site travel via a unique and consistent neural root. Second, injection of local aneasthetic totally abolishes sensory function of intended nerves and does not affect other nerves. Third, relief of pain after local anaesthetic block is attributable solely to block of the target afferent neural pathway. The validity of these assumptions is limited by complexities of anatomy, physiology, and psychology of pain perception and the effect of local anaesthetics on impulse conduction . Facet joints: The prevalence of zygapophyseal joint pain among patients with low back pain seems to be between 15% and 40% , but apparently only 7% of patients have pure facet pain [8, 29]. Facet blockade is achieved either by injection of local anaesthetic into the joint space or around the medial branches of the posterior medial rami of the spinal nerves that innervate the joint. There are several
Ozturk, Nilgun Kavrut; Baki, Elif Dogan; Kavakli, Ali Sait; Sahin, Ayca Sultan; Ayoglu, Raif Umut; Karaveli, Arzu; Emmiler, Mustafa; Inanoglu, Kerem; Karsli, Bilge
Background. Parasternal block and transcutaneous electrical nerve stimulation (TENS) have been demonstrated to produce effective analgesia and reduce postoperative opioid requirements in patients undergoing cardiac surgery. Objectives. To compare the effectiveness of TENS and parasternal block on early postoperative pain after cardiac surgery. Methods. One hundred twenty patients undergoing cardiac surgery were enrolled in the present randomized, controlled prospective study. Patients were assigned to three treatment groups: parasternal block, intermittent TENS application, or a control group. Results. Pain scores recorded 4 h, 5 h, 6 h, 7 h, and 8 h postoperatively were lower in the parasternal block group than in the TENS and control groups. Total morphine consumption was also lower in the parasternal block group than in the TENS and control groups. It was also significantly lower in the TENS group than in the control group. There were no statistical differences among the groups regarding the extubation time, rescue analgesic medication, length of intensive care unit stay, or length of hospital stay. Conclusions. Parasternal block was more effective than TENS in the management of early postoperative pain and the reduction of opioid requirements in patients who underwent cardiac surgery through median sternotomy. This trial is registered with Clinicaltrials.gov number NCT02725229.
Johnson, Thomas M; Badovinac, Rachel; Shaefer, Jeffry
Surveys were sent to Harvard School of Dental Medicine students and graduates from the classes of 2000 through 2006 to determine their current primary means of achieving mandibular anesthesia. Orthodontists and orthodontic residents were excluded. All subjects received clinical training in the conventional inferior alveolar nerve block and two alternative techniques (the Akinosi mandibular block and the Gow-Gates mandibular block) during their predoctoral dental education. This study tests the hypothesis that students and graduates who received training in the conventional inferior alveolar nerve block, the Akinosi mandibular block, and the Gow-Gates mandibular block will report more frequent current utilization of alternatives to the conventional inferior alveolar nerve block than clinicians trained in the conventional technique only. At the 95 percent confidence level, we estimated that between 3.7 percent and 16.1 percent (mean=8.5 percent) of clinicians trained in using the Gow-Gates technique use this injection technique primarily, and between 35.4 percent and 56.3 percent (mean=47.5 percent) of those trained in the Gow-Gates method never use this technique. At the same confidence level, between 0.0 percent and 3.8 percent (mean=0.0 percent) of clinicians trained in using the Akinosi technique use this injection clinical technique primarily, and between 62.2 percent and 81.1 percent (mean=72.3 percent) of those trained in the Akinosi method never use this technique. No control group that was completely untrained in the Gow-Gates or Akinosi techniques was available for comparison. However, we presume that zero percent of clinicians who have not been trained in a given technique will use the technique in clinical practice. The confidence interval for the Gow-Gates method excludes this value, while the confidence interval for the Akinosi technique includes zero percent. We conclude that, in the study population, formal clinical training in the Gow-Gates and
Hamilton, Thomas W; Athanassoglou, Vassilis; Trivella, Marialena; Strickland, Louise H; Mellon, Stephen; Murray, David; Pandit, Hemant G
Postoperative pain remains a significant issue with poor perioperative pain management associated with an increased risk of morbidity and mortality. Liposomal bupivacaine is an analgesic consisting of bupivacaine hydrochloride encapsulated within multiple, non-concentric lipid bi-layers offering a novel method of sustained release. To assess the analgesic efficacy and adverse effects of liposomal bupivacaine infiltration peripheral nerve block for the management of postoperative pain. We identified randomised trials of liposomal bupivacaine peripheral nerve block for the management of postoperative pain. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 1), Ovid MEDLINE (1946 to January Week 1 2016), Ovid MEDLINE In-Process (14 January 2016), EMBASE (1974 to 13 January 2016), ISI Web of Science (1945 to 14 January 2016), and reference lists of retrieved articles. We sought unpublished studies from Internet sources, and searched clinical trials databases for ongoing trials. The date of the most recent search was 15 January 2016. Randomised, double-blind, placebo- or active-controlled clinical trials of a single dose of liposomal bupivacaine administered as a peripheral nerve block in adults aged 18 years or over undergoing elective surgery at any surgical site. We included trials if they had at least two comparison groups for liposomal bupivacaine peripheral nerve block compared with placebo or other types of analgesia. Two review authors independently considered trials for inclusion in the review, assessed risk of bias, and extracted data. We performed analyses using standard statistical techniques as described in the Cochrane Handbook for Systematic Reviews of Interventions, using Review Manager 5. We planned to perform a meta-analysis, however there were insufficient data to ensure a clinically meaningful answer; as such we have produced a 'Summary of findings' table in a narrative format, and where possible we assessed the
Niu, Yuqing; Li, Linjing; Chen, Kevin C; Chen, Feiran; Liu, Xiangyu; Ye, Jianfu; Li, Wei; Xu, Kaitian
Nerve repair scaffolds from novel alternating block polyurethanes (PUCL-alt-PEG) based on PCL and PEG without additional growth factors or proteins were prepared by a particle leaching method. The scaffolds have pore size 10-20 µm and porosity 92%. Mechanical tests showed that the polyurethane scaffolds have maximum loads of 5.97 ± 0.35 N and maximal stresses of 8.84 ± 0.5 MPa. Histocompatiblity of the nerve repair scaffolds was tested in a SD rat model for peripheral nerve defect treatment. Two types of treatments including PUCL-alt-PEG scaffolds and autografts were compared in rat model. After 32 weeks, bridging of a 12 mm defect gap by the regenerated nerve was observed in all rats. The nerve regeneration was systematically characterized by sciatic function index (SFI), electrophysiology, histological assessment including HE staining, immunohistochemistry, ammonia sliver staining, Masson's trichrome staining and TEM observation. Results revealed that nerve repair scaffolds from PUCL-alt-PEG exhibit better regeneration effects compared to autografts. Electrophysiological recovery was seen in 90% and 87% of rats in PUCL-alt-PEG and autograft groups respectively. Biodegradation in vitro and in vivo shows good degradation match of PUCL-alt-PEG scaffolds with nerve regeneration. It demonstrates that plain nerve repair scaffolds from PUCL-alt-PEG biomaterials can achieve peripheral nerve regeneration satisfactorily.
Tosato, M.; Yoshida, K.; Toft, E.; Struijk, J. J.
The stimulation of the vagus nerve has been used as an anti-epileptic treatment for over a decade, and its use for depression and chronic heart failure is currently under investigation. Co-activation of the intrinsic laryngeal muscles may limit the clinical use of vagal stimulation, especially in the case of prolonged activation. To prevent this, the use of a selective stimulation paradigm has been tested in seven acute pig experiments. Quasi-trapezoidal pulses successfully blocked the population of the largest and fastest vagal myelinated fibers being responsible for the co-activation. The first response in the vagus compound action potential was reduced by 75 ± 22% (mean ± SD) and the co-activated muscle action potential by 67 ± 25%. The vagal bradycardic effects remained unchanged during the selective block, confirming the leading role of thin nerve fibers for the vagal control of the heart. Quasi-trapezoidal pulses may be an alternative to rectangular pulses in clinical vagal stimulation when the co-activation of laryngeal muscles must be avoided.
Abdallah, Faraj W; Madjdpour, Caveh; Brull, Richard
Total knee arthroplasty (TKA) is associated with moderate-to-severe postoperative pain despite the use of femoral nerve block (FNB). The analgesic benefits of adding sciatic nerve block (SNB) to FNB following TKA are unclear. The aim of this meta-analysis was to quantify the analgesic effects of adding SNB to FNB following TKA. We searched the US National Library of Medicine (MEDLINE), Excerpta Medica (Embase), and Cochrane Central Controlled Trials Register databases in March 2015 for randomized and quasi-randomized controlled trials (RCTs) that evaluated the analgesic advantages of adding SNB to FNB compared to FNB alone after TKA. The designated primary outcome was intravenous morphine consumption during the 24-hr postoperative interval. The severity of pain was evaluated at rest and with movement two, four, eight, 12, 24, 36, and 48 hr postoperatively. Morphine consumption during the postoperative 24-48 hr interval, time to first analgesic request, opioid-related side effects, block-related complications, patient satisfaction, functional recovery, and time to hospital discharge were also evaluated. Trials were stratified based on whether a single-shot SNB (SSNB) or continuous SNB (CSNB) was used. Data were combined using random effects modelling. Eight RCTs, including 379 patients, were analyzed. Five trials examined SSNB, and three assessed CSNB. Together, SSNB and CSNB reduced the 0-24 hr weighted mean difference [95% confidence interval] of morphine consumption by 10.6 [-20.9 to -0.3] mg (P = 0.042; I(2) = 97%) and 20.5 [-28.6 to -12.4] mg (P < 0.001, I(2) = 86%), respectively. SSNB reduced pain at rest and during movement up to 8 hr postoperatively (P = 0.023 and P < 0.001, respectively), whereas CSNB reduced pain at rest up to 36 hr (P = 0.004) and pain with movement up to 48 hr (P = 0.031). CSNB also decreased the odds of postoperative nausea and vomiting by 91% (P = 0.011). The available evidence supporting the analgesic benefits of adding SNB to FNB
Martínez González, José Ma; Benito Peña, Begoña; Fernández Cáliz, Fernando; San Hipólito Marín, Lara; Peñarrocha Diago, Miguel
A study is made of 56 patients subjected to lower molar extraction, comparing the efficacy of the Akinosi technique as an alternative to direct or conventional mandibular nerve block in two groups of 28 subjects each. The parameters evaluated were pain in response to puncture, percentage positive aspiration, latency, pain during the intervention and complications. Patient pain in response to puncture was comparatively less intense and frequent with the Akinosi technique. The latency to anesthesia was briefer with conventional mandibular block than with the Akinosi technique (2.9 versus 3.8 minutes). Pain during the intervention and the duration of the anesthetic effect were similar for both techniques. The patients anesthetized with the Akinosi technique required more buccal nerve reinforcement infiltrations to complete the procedure. The anesthetic failure rates were 10.7% and 17.8% for the conventional and Akinosi technique, respectively. It is concluded that while the Akinosi technique can be used to extract lower molars, direct mandibular block offers superior anesthetic performance.
Wang, Zi; Huang, Haizhen; Yang, Shaozhong; Huang, Shanshan; Guo, Jingxuan; Tang, Qi; Qi, Feng
Purpose The analgesic effect of ropivacaine (Rop) for nerve block lasts only ~3–6 hours for single use. The aim of this study was to develop long-acting regional anesthetic Rop nanoparticles and investigate the effects of sciatic nerve block on postoperative pain in rats. Materials and methods Rop nanoparticles were developed using polyethylene glycol-co-polylactic acid (PELA). One hundred and twenty adult male Wistar rats were randomly divided into four groups (n=30, each): Con (control group; 0.9% saline, 200 µL), PELA (PELA group; 10 mg), Rop (Rop group; 0.5%, 200 µL), and Rop-PELA (Rop-PELA group; 10%, 10 mg). Another 12 rats were used for the detection of Rop concentration in plasma. The mechanical withdrawal threshold and thermal withdrawal latency were measured at 2 hours, 4 hours, 8 hours, 1 day, 2 days, 3 days, 5 days, and 7 days after incision. The expression of c-FOS was determined by immunohistochemistry at 2 hours, 8 hours, 48 hours, and 7 days. Nerve and organ toxicities were also evaluated at 7 days. Results The duration of Rop absorption in the plasma of the Rop-PELA group was longer (>8 hours) than that of the Rop group (4 hours). Mechanical withdrawal threshold and thermal withdrawal latency in the Rop-PELA group were higher than that in other groups (4 hours–3 days). c-FOS expression in the Rop-PELA group was lower than that in the control group at 2 hours, 8 hours, and 48 hours and lower than that in the Rop group at 8 hours and 48 hours after paw incision. Slight foreign body reactions were observed surrounding the sciatic nerve at 7 days. No obvious pathophysiological change was found in the major organs after Rop-PELA administration at 7 days. Conclusion Rop-PELA provides an effective analgesia for nerve block over 3 days after single administration, and the analgesic mechanism might be mediated by the regulation of spinal c-FOS expression. However, its potential long-term tissue toxicity needs to be further investigated. PMID:27274236
Patzkowski, Michael S
Ehlers-Danlos syndrome is an inherited disorder of collagen production that results in multiorgan dysfunction. Patients with hypermobility type display skin hyperextensibility and joint laxity, which can result in chronic joint instability, dislocation, peripheral neuropathy, and severe musculoskeletal pain. A bleeding diathesis can be found in all subtypes of varying severity despite a normal coagulation profile. There have also been reports of resistance to local anesthetics in these patients. Several sources advise against the use of regional anesthesia in these patients citing the 2 previous features. There have been reports of successful neuraxial anesthesia, but few concerning peripheral nerve blocks, none of which describe nerves of the lower extremity. This report describes 2 cases of successful peripheral regional anesthesia in the lower extremity. In case 1, a 16-year-old adolescent girl with hypermobility type presented for osteochondral grafting of tibiotalar joint lesions. She underwent a popliteal sciatic (with continuous catheter) and femoral nerve block under ultrasound guidance. She proceeded to surgery and tolerated the procedure under regional block and intravenous sedation. She did not require any analgesics for the following 15 hours. In case 2, an 18-year-old woman with hypermobility type presented for medial patellofemoral ligament reconstruction for chronic patella instability. She underwent a saphenous nerve block above the knee with analgesia in the distribution of the saphenous nerve lasting for approximately 18 hours. There were no complications in either case. Prohibitions against peripheral nerve blocks in patients with Ehlers-Danlos syndrome, hypermobility type, appear unwarranted.
Blanchet, G.; Lallement, G.; Carpentier, P.; De Groot, D.; Bodjarian, N.
Our recent studies concerning soman-induced seizures mechanisms and subsequent brain damage are reviewed. (1) Seizure activity was associated with transient increases of extracellular concentrations of acetylcholine (ACh) and with long-lasting releases of glutamate (Glu) in all limbic areas studied. (2) Preventive intraseptal application of atropine abolished the hippocampal increases of extracellular AChi and Glu indicating a key role of septum in triggering seizure activity. (3) Early increases of hippocampal AMPA receptor binding occurred before activation of NMDA receptors. (4) Pretreatment with NBQX, an antagonist of AMPA receptor, prevented convulsions and brain damage even without atropine. In the same conditions, no protection was afforded by TCP, a non-competitive antagonist of the NMDA receptor. (5) On the contrary, in the presence of pyridostigmine and atropine, TCP blocked the seizures induced by 2 x LD50 of soman. The anticonvulsant potency of TCP was particularly obvious when administered curatively. (6) Mossy fibers sprouting takes place in the supragranular-molecular layers of rat hippocampus long after brain injury associated with abnormal neuronal excitability. (7) Altogether, it appears that an AMPA component is involved in combination with cholinergic mechanisms in initiating seizures. A subsequent and long-lasting recruitment of NMDA receptors is then essential in sustaining the seizures. New anticonvulsant and neuroprotective approaches using Glu antagonists against nerve agents intoxication are discussed.
Wang, Duan; Yang, Yang; Li, Qi; Tang, Shen-Li; Zeng, Wei-Nan; Xu, Jin; Xie, Tian-Hang; Pei, Fu-Xing; Yang, Liu; Li, Ling-Li; Zhou, Zong-Ke
Femoral nerve blocks (FNB) can provide effective pain relief but result in quadriceps weakness with increased risk of falls following total knee arthroplasty (TKA). Adductor canal block (ACB) is a relatively new alternative providing pure sensory blockade with minimal effect on quadriceps strength. The meta-analysis was designed to evaluate whether ACB exhibited better outcomes with respect to quadriceps strength, pain control, ambulation ability, and complications. PubMed, Embase, Web of Science, Wan Fang, China National Knowledge Internet (CNKI) and the Cochrane Database were searched for RCTs comparing ACB with FNB after TKAs. Of 309 citations identified by our search strategy, 12 RCTs met the inclusion criteria. Compared to FNB, quadriceps maximum voluntary isometric contraction (MVIC) was significantly higher for ACB, which was consistent with the results regarding quadriceps strength assessed with manual muscle strength scale. Moreover, ACB had significantly higher risk of falling versus FNB. At any follow-up time, ACB was not inferior to FNB regarding pain control or opioid consumption, and showed better range of motion in comparison with FNB. ACB is superior to the FNB regarding sparing of quadriceps strength and faster knee function recovery. It provides pain relief and opioid consumption comparable to FNB and is associated with decreased risk of falls. PMID:28079176
Rice, David C; Cata, Juan P; Mena, Gabriel E; Rodriguez-Restrepo, Andrea; Correa, Arlene M; Mehran, Reza J
Pain relief using regional neuroaxial blockade is standard care for patients undergoing major thoracic surgery. Thoracic epidural analgesia (TEA) provides effective postoperative analgesia but has unwanted side effects, including hypotension, urinary retention, nausea, and vomiting, and is highly operator dependent. Single-shot intercostal nerve and paravertebral blockade have not been widely used because of the short duration of action of most local anesthetics; however, the recent availability of liposomal bupivacaine (LipoB) offers the potential to provide prolonged blockade of intercostal nerves (72 to 96 hours). We hypothesized that a five-level unilateral posterior intercostal nerve block using LipoB would provide effective analgesia for patients undergoing thoracic surgery. We identified patients who underwent lung resection using intraoperative LipoB posterior intercostal nerve blockade and retrospectively compared them with a group of patients who had TEA and who were matched for age, sex, type of surgery, and surgical approach. We analyzed perioperative morbidity, pain scores and narcotic requirements. There were 54 patients in each group. Mean hospital stay was 3.5 days and 4.5 days (p = 0.004) for LipoB group and TEA group, respectively. There were no significant differences in perioperative complications, postoperative pain scores, or in narcotic utilization between LipoB group and TEA group. No acute toxicity related to LipoB was observed. Posterior intercostal nerve blockade using LipoB is safe and provides effective analgesia for patients undergoing thoracic surgery. It may be considered as a suitable alternative to TEA. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
Clark, Kenneth; Reader, Al; Beck, Mike; Meyers, William J.
The purpose of this prospective, randomized, blinded study was to measure the degree of pulpal anesthesia obtained with an inferior alveolar nerve (IAN) block followed by an infiltration in mandibular anterior teeth. Through use of a repeated-measures design, 40 patients randomly received 3 injection combinations at 3 separate appointments: an IAN block followed by a mock lingual infiltration and a mock labial infiltration, an IAN block followed by a mock lingual infiltration and a labial infiltration, and an IAN block followed by a mock labial infiltration and a lingual infiltration. Each IAN block used 3.6 mL of 2% lidocaine with 1:100,000 epinephrine, and each infiltration used 1.8 mL of 2% lidocaine with 1:100,000 epinephrine administered over the lateral incisor apex. Mandibular anterior teeth were blindly pulp tested at 2-minute cycles for 60 minutes following the IAN-infiltration injections. No response from the patient to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive 80 readings were obtained within 15 minutes and the 80 reading was sustained for 60 minutes. Anesthesia was considered a failure if 2 consecutive 80 readings were not obtained during the 60 minutes. The results of this study showed that 100% of the patients had lip numbness with all IAN blocks. For the lateral incisor, the success rate of the IAN block alone was 40% and the failure rate was 30%. For the IAN block plus labial infiltration, the success rate was 62% and the failure rate was 12% for the lateral incisor. There was a significant difference (P < .05) between the IAN block alone and the IAN block plus labial infiltration. In conclusion, a labial infiltration, over the lateral incisor apex, of 1.8 mL of 2% lidocaine with 1:100,000 epinephrine following an IAN block significantly improved pulpal anesthesia for the lateral incisor compared with the IAN block alone. PMID:15384292
Li, Guangyao; Li, Dandan; Niu, Yuqing; He, Tao; Chen, Kevin C; Xu, Kaitian
Polyurethanes with regular and controlled block arrangement, i.e., alternating block polyurethanes (abbreviated as PUCL-alt-PEG) based on poly(ε-caprolactone) (PCL-diol) and poly(ethylene glycol) (PEG) was prepared via selectively coupling reaction between PCL-diol and diisocyanate end-capped PEG. Chemical structure, molecular weight, distribution, and thermal properties were systematically characterized by FTIR, (1)H NMR, GPC, DSC, and TGA. Hydrophilicity was studied by static contact angle of H2O and CH2I2. Film surface was observed by scanning electron microscope (SEM) and atomic force microscopy, and mechanical properties were assessed by universal test machine. Results show that alternating block polyurethanes give higher crystal degree, higher mechanical properties, and more hydrophilic and rougher (deep ravine) surface than their random counterpart, due to regular and controlled structure. Platelet adhesion illustrated that PUCL-alt-PEG has better hemocompatibility and the hemacompatibility was affected significantly by PEG content. Excellent hemocompatibility was obtained with high PEG content. CCK-8 assay and SEM observation revealed much better cell compatibility of fibroblast L929 and rat glial cells on the alternating block polyurethanes than that on random counterpart. Alternating block polyurethane PUC20-a-E4 with optimized composition, mechanical, surface properties, hemacompatibility, and highest cell growth and proliferation was achieved for potential use in nerve regeneration.
Gunning, P; Smith, A; Fox, V; Bolt, D M; Lowe, J; Sinclair, C; Witte, T H; Weller, R
Lameness is the most common presenting complaint in equine practice. Performing diagnostic nerve blocks is an integral part of any lameness work-up, and is therefore an essential skill for equine practitioners. However, the opportunities for veterinary students to practice this skill are limited. The aim of this study was to design and validate an equine nerve block simulator. It was hypothesised that the simulator would improve students' ability and enhance their confidence in performing nerve blocks. A simulator was built using an equine forelimb skeleton and building foam. Wire wool targets were placed under the foam in the positions corresponding to the anatomical location of the most palmar digital, abaxial and low four-point nerve blocks and attached to an electrical circuit. The circuit became complete when the operator placed a needle in the correct position and immediate audible feedback with a buzzer was provided. To validate the simulator, it was compared with two established teaching methods: cadaver training and theoretical training with a hand-out. Cadaver-trained students achieved the best results (73 per cent correct blocks), compared with simulator-trained students (71 per cent correct blocks), and a hand-out trained group (58 per cent correct blocks). Feedback obtained with a questionnaire showed that students enjoyed simulator training more, and that they felt more confident in performing diagnostic nerve blocks than the other two groups. The equine nerve block simulator provides a safe, cost-effective method to supplement the teaching of diagnostic analgesia to undergraduate veterinary students.
Reddy, Rahul; Kendall, Mark C.; Nader, Antoun; Weeks, Jessica J.
Continuous brachial plexus nerve block catheters are commonly inserted for postoperative analgesia after upper extremity surgery. Modifications of the insertion technique have been described to improve the safety of placing an infraclavicular brachial plexus catheter. Rarely, these catheters may become damaged or entrapped, complicating their removal. We describe a case of infraclavicular brachial plexus catheter entrapment related to differences in arm positioning during catheter placement and removal. Written authorization to obtain, use, and disclose information and images was obtained from the patient. PMID:28348896
Bailey, Edmund; Rao, Jeethendra; Saksena, Alka
Fortunately, needle fracture is a rare complication following the administration of dental local anaesthetic. We present a case of needle fracture following administration of an inferior dental nerve block. The fractured needle was retrieved successfully under general anaesthetic. We also provide some suggestions on how to prevent needle fracture, and advice on how to manage the situation should it arise. Clinical Relevance: Dental practitioners are the largest user group of local anaesthesia in the UK. It is important that practitioners are aware of the risks to the patient of needle fracture, how to minimize the risk of this occurring and be aware of how to manage the situation should it arise.
Vandenbeuch, Aurelie; Voigt, Anja; Meyerhof, Wolfgang; Kinnamon, Sue C.; Finger, Thomas E.
Activation of taste buds triggers the release of several neurotransmitters, including ATP and serotonin (5-hydroxytryptamine; 5-HT). Type III taste cells release 5-HT directly in response to acidic (sour) stimuli and indirectly in response to bitter and sweet tasting stimuli. Although ATP is necessary for activation of nerve fibers for all taste stimuli, the role of 5-HT is unclear. We investigated whether gustatory afferents express functional 5-HT3 receptors and, if so, whether these receptors play a role in transmission of taste information from taste buds to nerves. In mice expressing GFP under the control of the 5-HT3A promoter, a subset of cells in the geniculate ganglion and nerve fibers in taste buds are GFP-positive. RT-PCR and in situ hybridization confirmed the presence of 5-HT3A mRNA in the geniculate ganglion. Functional studies show that only those geniculate ganglion cells expressing 5-HT3A-driven GFP respond to 10 μm 5-HT and this response is blocked by 1 μm ondansetron, a 5-HT3 antagonist, and mimicked by application of 10 μm m-chlorophenylbiguanide, a 5-HT3 agonist. Pharmacological blockade of 5-HT3 receptors in vivo or genetic deletion of the 5-HT3 receptors reduces taste nerve responses to acids and other taste stimuli compared with controls, but only when urethane was used as the anesthetic. We find that anesthetic levels of pentobarbital reduce taste nerve responses apparently by blocking the 5-HT3 receptors. Our results suggest that 5-HT released from type III cells activates gustatory nerve fibers via 5-HT3 receptors, accounting for a significant proportion of the neural taste response. SIGNIFICANCE STATEMENT Historically, serotonin (5-hydroxytryptamine; 5-HT) has been described as a candidate neurotransmitter in the gustatory system and recent studies show that type III taste receptor cells release 5-HT in response to various taste stimuli. In the present study, we demonstrate that a subset of gustatory sensory neurons express functional
Damjanovska, M; Cvetko, E; Hadzic, A; Seliskar, A; Plavec, T; Mis, K; Vuckovic Hasanbegovic, I; Stopar Pintaric, T
Liposomal bupivacaine is a prolonged-release local anaesthetic, the neurotoxicity of which has not yet been determined. We used quantitative histomorphometric and immunohistochemical analyses to evaluate the neurotoxic effect of liposomal bupivacaine after perineural and intraneural (extrafascicular) injection of the sciatic nerve in pigs. In this double-blind prospective randomised trial, 4 ml liposomal bupivacaine 1.3% was injected either perineurally (n = 5) or intraneurally extrafascicularly (n = 5). Intraneural-extrafascicular injection of saline (n = 5) was used as a control. After emergence from anaesthesia, neurological examinations were conducted over two weeks. After harvesting the sciatic nerves, no changes in nerve fibre density or myelin width indicative of nerve injury were observed in any of the groups. Intraneural injections resulted in longer sensory blockade than perineural (p < 0.003) without persistent motor or sensory deficit. Sciatic nerve block with liposomal bupivacaine in pigs did not result in histological evidence of nerve injury.
Reina, M A; Arriazu, R; Collier, C B; Sala-Blanch, X; Izquierdo, L; de Andrés, J
The goal is to describe the ultrastructure of normal human peripheral nerves, and to highlight key aspects that are relevant to the practice of peripheral nerve block anaesthesia. Using samples of sciatic nerve obtained from patients, and dural sac, nerve root cuff and brachial plexus dissected from fresh human cadavers, an analysis of the structure of peripheral nerve axons and distribution of fascicles and topographic composition of the layers that cover the nerve is presented. Myelinated and unmyelinated axons, fascicles, epineurium, perineurium and endoneurium obtained from patients and fresh cadavers were studied by light microscopy using immunohistochemical techniques, and transmission and scanning electron microscopy. Structure of perineurium and intrafascicular capillaries, and its implications in blood-nerve barrier were revised. Each of the anatomical elements is analyzed individually with regard to its relevance to clinical practice to regional anaesthesia. Routine practice of regional anaesthetic techniques and ultrasound identification of nerve structures has led to conceptions, which repercussions may be relevant in future applications of these techniques. In this regard, the ultrastructural and histological perspective accomplished through findings of this study aims at enlightening arising questions within the field of regional anaesthesia. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.
Charous, Matthew T.; Madison, Sarah J.; Suresh, J.; Sandhu, NavParkash S.; Loland, Vanessa J.; Mariano, Edward R.; Donohue, Michael C.; Dutton, Pascual H.; Ferguson, Eliza J.; Ilfeld, Brian M.
Background Whether the method of local anesthetic administration for continuous femoral nerve blocks —basal infusion versus repeated hourly bolus doses —influences block effects remains unknown. Methods Bilateral femoral perineural catheters were inserted in volunteers (n = 11). Ropivacaine 0.1% was administered through both catheters concurrently: a 6-h continuous 5 ml/h basal infusion on one side and 6 hourly bolus doses on the contralateral side. The primary endpoint was the maximum voluntary isometric contraction (MVIC) of the quadriceps femoris muscle at Hour 6. Secondary end points included quadriceps MVIC at other time points, hip adductor MVIC, and cutaneous sensation 2 cm medial to the distal quadriceps tendon in the 22 h following local anesthetic administration initiation. Results Quadriceps MVIC for limbs receiving 0.1% ropivacaine as a basal infusion declined by a mean (SD) of 84% (19) compared with 83% (24) for limbs receiving 0.1% ropivacaine as repeated bolus doses between baseline and Hour 6 (paired t test P = 0.91). Intrasubject comparisons (left vs. right) reflected a lack of difference as well: the mean basal-bolus difference in quadriceps MVIC at Hour 6 was −1.1% (95% CI −22.0 to 19.8%). The similarity did not reach our a priori threshold for concluding equivalence, which was the 95% CI falling within ± 20%. There were similar minimal differences in the secondary endpoints during local anesthetic administration. Conclusions This study did not find evidence to support the hypothesis that varying the method of local anesthetic administration —basal infusion versus repeated bolus doses —influences continuous femoral nerve block effects to a clinically significant degree. PMID:21394001
Assad, Salman; Assad, Shuja
Injury to the recurrent laryngeal nerve (RLN) is a well known, though less frequent, complication of parathyroid surgery. In recent years, the use of intraoperative nerve monitoring (IONM) has gained popularity amongst surgeons when operating on thyroid gland; however, its utilization in parathyroid surgery is not established. This trend continues to rise, despite multiple studies documenting no statistically significant difference that IONM decreases the incidence of RLN injury. Most surgeons use this technology as an adjunct to visualization alone for identification of RLN. The purpose of this review is to discuss the possible role of IONM in parathyroid surgery with regards to the accuracy, efficacy, and recent trends in the utilization of this technology. There is insufficient evidence that IONM reduces the risk of RLN injury in parathyroidectomy. Although IONM may decrease the likelihood of nerve injury by helping to identify and map the RLN during thyroidectomy, we did not find studies exclusive to parathyroid surgery to see if its use can be supported for parathyroidectomy. Despite this lack of evidence, we believe that IONM is a promising adjunct to visualization alone in detecting nerve structures during neck dissection, but more clinical trials are warranted to establish its role in preventing nerve injury in parathyroid surgery. PMID:28003944
Larson, Eric D; Vandenbeuch, Aurelie; Voigt, Anja; Meyerhof, Wolfgang; Kinnamon, Sue C; Finger, Thomas E
Activation of taste buds triggers the release of several neurotransmitters, including ATP and serotonin (5-hydroxytryptamine; 5-HT). Type III taste cells release 5-HT directly in response to acidic (sour) stimuli and indirectly in response to bitter and sweet tasting stimuli. Although ATP is necessary for activation of nerve fibers for all taste stimuli, the role of 5-HT is unclear. We investigated whether gustatory afferents express functional 5-HT3 receptors and, if so, whether these receptors play a role in transmission of taste information from taste buds to nerves. In mice expressing GFP under the control of the 5-HT(3A) promoter, a subset of cells in the geniculate ganglion and nerve fibers in taste buds are GFP-positive. RT-PCR and in situ hybridization confirmed the presence of 5-HT(3A) mRNA in the geniculate ganglion. Functional studies show that only those geniculate ganglion cells expressing 5-HT3A-driven GFP respond to 10 μM 5-HT and this response is blocked by 1 μM ondansetron, a 5-HT3 antagonist, and mimicked by application of 10 μM m-chlorophenylbiguanide, a 5-HT3 agonist. Pharmacological blockade of 5-HT3 receptors in vivo or genetic deletion of the 5-HT3 receptors reduces taste nerve responses to acids and other taste stimuli compared with controls, but only when urethane was used as the anesthetic. We find that anesthetic levels of pentobarbital reduce taste nerve responses apparently by blocking the 5-HT3 receptors. Our results suggest that 5-HT released from type III cells activates gustatory nerve fibers via 5-HT3 receptors, accounting for a significant proportion of the neural taste response.
Zhou, Yangning; He, Miao; Zou, Tianxiao; Yu, Bin
Objective: To investigate the morphological changes in various tissues of rabbits receiving sciatic nerve block with 0.2% ropivacaine for 48 h. Methods: Twenty healthy were randomly assigned to normal saline group (N group) and ropivacaine group (R group). The right sciatic nerve was exposed, and a nerve-blocking trocar cannula embedded. Animals received an injection of 0.5% ropivacaine hydrochloride at a dose of 0.75 ml/kg. Rabbit was then connected to an infusion pump containing 50 ml of normal saline in N group, or to a infusion pump containing 0.2% ropivacaine hydrochloride in R group at 0.25 ml/kg•h-1. Results: In both R group and N group, a small number of nerve cells exhibited pyknotic degeneration. More nerve cells with pyknotic degeneration were found in R group than in N group (P<0.001). At 48 h after surgery, there was a significant correlation between the abnormality of right hind limb and the degree of edema in sciatic nerve (P<0.01). Conclusion: Pyknotic degeneration of sciatic nerve increased after an infusion of 0.2% ropivacaine hydrochloride for 48 h, suggesting the neurotoxicity of ropivacaine. An infusion of 0.2% ropivacaine hydrochloride for 48 h may cause necrosis of skeletal muscle cells. The sciatic nerve edema would greatly affect the hindlimb motor while both pyknotic degeneration of sciatic nerve and skeletal muscle have little influence on the hindlimb movement. After an infusion of 0.2% ropivacaine hydrochloride for 48 h, the morphology of right atrium and brain tissues around the ventriculus tertius and medulla oblongata remained unchanged. PMID:26823703
da Silva-Alves, Kerly Shamyra; Ferreira-da-Silva, Francisco Walber; Coelho-de-Souza, Andrelina Noronha; Albuquerque, Aline Alice Cavalcante; do Vale, Otoni Cardoso; Leal-Cardoso, José Henrique
Croton zehntneri is an aromatic plant native to Northeast Brazil and employed by local people to treat various diseases. The leaves of this plant have a rich content of essential oil. The essential oil of C. zehntneri samples, with anethole as the major constituent and anethole itself, have been reported to have several pharmacological activities such as antispasmodic, cardiovascular, and gastroprotective effects and inducing the blockade of neuromuscular transmission and antinociception. Since several works have demonstrated that essential oils and their constituents block cell excitability and in view of the multiple effects of C. zehntneri essential oil and anethole on biological tissues, we undertook this investigation aiming to characterize and compare the effects of this essential oil and its major constituent on nerve excitability. Sciatic nerves of Wistar rats were used. They were mounted in a moist chamber, and evoked compound action potentials were recorded. Nerves were exposed in vitro to the essential oil of C. zehntneri and anethole (0.1-1 mg/mL) up to 180 min, and alterations in excitability (rheobase and chronaxie) and conductibility (peak-to-peak amplitude and conduction velocity) parameters of the compound action potentials were evaluated. The essential oil of C. zehntneri and anethole blocked, in a concentration-dependent manner with similar pharmacological potencies (IC50: 0.32 ± 0.07 and 0.22 ± 0.11 mg/mL, respectively), rat sciatic nerve compound action potentials. Strength-duration curves for both agents were shifted upward and to the right compared to the control curve, and the rheobase and chronaxie were increased following essential oil and anethole exposure. The time courses of the essential oil of C. zehntneri and anethole effects on peak-to-peak amplitude of compound action potentials followed an exponential decay and reached a steady state. The essential oil of C. zehntneri and anethole caused a similar reduction in
Alvarez, L; De Luna, J B; Gamboa, D; Reyes, M; Sánchez, A; Terrazas, A; Rojas, S; Galindo, F
Plasma cortisol and behavior were measured in disbudded goat kids with and without the use of cornual nerve block. A total of 45 kids were used in 5 experimental groups (n=9, males and females). Group LidoD was infiltrated with 1 mL of 2% lidocaine locally at the cornual branches of lacrimal and infratrochlear nerves, 15 min before thermal disbudding. Group Lido was similarly infiltrated and was not disbudded. In group Sim, the disbudding procedure was simulated. A control group (CD) was disbudded without lidocaine infiltration, and group SD was infiltrated with saline before disbudding. The cornual nerve block did not prevent the short-term increase in cortisol levels during and after disbudding. LidoD, CD and SD groups showed higher cortisol concentrations than Lido and Sim (p<0.05) during the first 20 min after the procedure. Frequency of vocalizations during the procedure was significantly different between groups and was higher in SD (29.6 ± 3.1; mean±SE) and CD (28.4 ± 3.1) than in Sim (16.6 ± 3.1; p<0.05). Infiltrating lidocaine did not decrease this response to disbudding (21.1 ± 3.1; p>0.05). Struggles tended to be higher in SD (16.5 ± 2.5), CD (17.8 ± 2.5) and LidoD (15.6 ± 2.5) than Sim (10.6 ± 2.5; p=0.1). The total behavioral response was different between groups (CD, 59.6 ± 6.8; LidoD, 52 ± 6.8; SD, 62.6 ± 6.8; Sim, 36.8 ± 6.8; p=0.05), and disbudded animals showed the strongest reactions (disbudded, 58.1 ± 3.9 vs non-disbudded, 36.8 ± 6.8; p=0.01). It was concluded that cornual nerve block (lacrimal and infratrochlear) using 2% lidocaine did not prevent pain during thermal disbudding of goat kids.
Borg, Lindsay; Howard, Steven K; Kim, T Edward; Steffel, Lauren; Shum, Cynthia; Mariano, Edward R
Despite the benefits of continuous peripheral nerve blocks, catheter dislodgment remains a major problem, especially in the ambulatory setting. However, catheter dressing techniques to prevent such dislodgment have not been studied rigorously. We designed this simulation study to test the strength of two commercially available catheter dressings. Using a cadaver model, we randomly assigned 20 trials to one of two dressing techniques applied to the lateral thigh: 1) clear adhesive dressing alone, or 2) clear adhesive dressing with an anchoring device. Using a digital luggage scale attached to a loop secured by the dressing, the same investigator applied steadily increasing force with a downward trajectory towards the floor until the dressing was removed or otherwise disrupted. The weight, measured (median [10th-90th percentile]) at the time of dressing disruption or removal, was 1.5 kg (1.3-1.8 kg) with no anchoring device versus 4.9 kg (3.7-6.5 kg) when the dressing included an anchoring device (P < 0.001). Based on this simulation study, using an anchoring device may help prevent perineural catheter dislodgement and therefore premature disruption of continuous nerve block analgesia.
Adey-Wakeling, Zoe; Crotty, Maria; Shanahan, E Michael
Shoulder pain is a common complication after stroke that can impede participation in rehabilitation and has been associated with poorer outcomes. Evidence-based treatments for hemiplegic shoulder pain are limited. Suprascapular nerve block (SSNB) is a safe and effective treatment of shoulder pain associated with arthritic shoulder conditions, but its usefulness in a stroke population is unclear. We undertook a randomized controlled trial assessing the effectiveness of SSNB in a population of 64 stroke patients (onset < 1 year) with hemiplegic shoulder pain. The primary outcome was pain measured on a visual analogue scale (VAS). Secondary outcomes were disability (Modified Rankin Scale, Croft Disability Index) and quality of life (EuroQol Health Questionnaire). All participants were assessed before randomization, and at 1, 4, and 12 weeks postintervention. Both groups continued with routine therapy. Although both intervention and control groups demonstrated reduction in pain score, participants who received SSNB consistently demonstrated superior, statistically significant pain reduction compared with placebo. Mean VAS reduction in the SSNB group was >18 mm greater than participants receiving placebo injection. The number needed to treat with SSNB to reduce 1 stroke survivor's pain by 50% at 4 weeks is 4. No significant differences in function or quality of life were observed. No adverse events were reported. Suprascapular nerve block is a safe and effective treatment for patients with hemiplegic shoulder pain. http://www.anzctr.org.au. Unique identifier: ACTRN12609000621213.
Isiordia-Espinoza, Mario Alberto; Orozco-Solis, Mariana; Tobías-Azúa, Francisco Javier; Méndez-Gutiérrez, Elsa Patricia
The purpose of this study was to evaluate the effect of submucous tramadol as adjuvant of mepivacaine with epinephrine in inferior alveolar nerve block. A double-blind, randomized, placebo-controlled, crossover clinical trial was conducted. Twenty healthy young volunteers were randomized into two treatment sequences using a series of random numbers. Sequence 1: Group A, 2% mepivacaine with 1:100,000 epinephrine plus submucous tramadol 50mg (1mL of saline) and one week later Group B, 2% mepivacaine with 1:100,000 epinephrine plus submucous placebo (1mL of saline). Sequence 2: Group B and one week later Group A. All treatments were administered 1min after that patient informed anesthesia of lower lip. We evaluated the duration of anesthesia of lower lip, anesthetic efficacy, and local and systemic adverse events. Anesthetic efficacy was better in group receiving submucous tramadol during the first 2h compared with group receiving submucous placebo (P<0.05). Submucous tramadol increased the anesthetic efficacy of mepivacaine with epinephrine of soft tissue in inferior alveolar nerve block.
Feriani, Gustavo; Hatanaka, Eric; Torloni, Maria R; da Silva, Edina M K
Postoperative pain is a barrier to the quality of paediatric care, the proper management of which is a challenge. Acute postoperative pain often leads to adverse functional and organic consequences that may compromise surgical outcome. Cleft lip is one of the most common craniofacial birth defects and requires surgical correction early in life. As expected after a surgical intervention in such a sensitive and delicate area, the immediate postoperative period of cleft lip repair may be associated with moderate to severe pain. Infraorbital nerve block associated with general anaesthesia has been used to reduce postoperative pain after cleft lip repair. To assess the effects of infraorbital nerve block for postoperative pain following cleft lip repair in children. We searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL, the Cochrane Library, Issue 6, 2015), MEDLINE, EMBASE, and Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) from inception to 17 June 2015. There were no language restrictions. We searched for ongoing trials in the following platforms: the metaRegister of Controlled Trials; ClinicalTrials.gov (the US National Institutes of Health Ongoing Trials Register), and the World Health Organization International Clinical Trials Registry Platform (on 17 June 2015). We checked reference lists of the included studies to identify any additional studies. We contacted specialists in the field and authors of the included trials for unpublished data. We included randomised controlled clinical trials that tested perioperative infraorbital nerve block for cleft lip repair in children, compared with other types of analgesia procedure, no intervention, or placebo (sham nerve block). We considered the type of drug, dosage, and route of administration used in each study. For the purposes of this review, the term 'perioperative' refers to the three phases of surgery, that is preoperative, intraoperative, and
Castañeda-Herrera, F E; Buriticá-Gaviria, E F; Echeverry-Bonilla, D F
Transversus abdominis plane (TAP) is a fascial plane containing the thoracolumbar nerve branches that innervate the abdominal wall. Limited information is available on the anatomical organization of these nerve branches in the dog, which is of great importance for the success of the TAP block anaesthetic technique. The aim of this study was to describe the origin and conformation of thoracolumbar nerves running through the TAP in 20 hemi-abdominal walls of 10 adult mongrel dog cadavers with an average body weight of 12.6 kg (range: 9.6-15.6). The abdominal walls were dissected from superficial to deep direction, the skin and both obliquus externus abdominis and obliquus internus abdominis muscles were dissected and reflected dorsally to expose the transversus abdominis muscle and the thoracolumbar nerve branches located in this plane. The anatomical features of ventral nerve branches were described. The thoracic nerve branches: T7-T12 and costoabdominalis; and the lumbar nerve branches: iliohypogastricus cranialis, iliohypogastricus caudalis, ilioinguinalis and cutaneus femoris lateralis were identified in all the cadavers. Anatomical variations related to the presence or absence within the TAP of the T7, T8 and T9 nerve branches were found. These variations should be taken into account when planning the TAP block technique in dogs. © 2017 Blackwell Verlag GmbH.
Schenck, Marcus; Schenck, Catarina; Rübben, Herbert; Stuschke, Martin; Schneider, Tim; Eisenhardt, Andreas; Rossi, Roberto
In male patients, the pudendal block was applied only in rare cases as a therapy of neuralgia of the pudendal nerve. We compared pudendal nerve block (NPB) and combined spinal-epidural anesthesia (CSE) in order to perform a pain-free high-dose-rate (HDR) brachytherapy in a former pilot study in 2010. Regarding this background, in the present study, we only performed the bilateral perineal infiltration of the pudendal nerve. In 25 patients (71.8 ± 4.18 years) suffering from a high-risk prostate carcinoma, we performed the HDR-brachytherapy with the NPB. The perioperative compatibility, the subjective feeling (German school marks principle 1-6), subjective pain (VAS 1-10) and the early postoperative course (mobility, complications) were examined. All patients preferred the NPB. There was no change of anesthesia form necessary. The expense time of NPB was 10.68 ± 2.34 min. The hollow needles (mean 24, range 13-27) for the HDR-brachytherapy remained on average 79.92 ± 12.41 min. During and postoperative, pain feeling was between 1.4 ± 1.08 and 1.08 ± 1.00. A transurethral 22 French Foley catheter was left in place for 6 h. All patients felt the bladder catheter as annoying, but they considered postoperative mobility as more important as complete lack of pain. The subjective feeling was described as 2.28 ± 0.74. Any side effects or complications did not appear. Bilateral NPB is a safe and effective analgesic option in HDR-brachytherapy and can replace CSE. It offers the advantage of almost no impaired mobility of the patient and can be performed by the urologist himself. Using transrectal ultrasound guidance, the method can be learned quickly.
Couture, Darren J; Cuniff, Heather M; Maye, John P; Pellegrini, Joseph
Clonidine has been shown to prolong sensory analgesia when given as an adjunct to peripheral nerve blocks but has not been evaluated when given in conjunction with a femoral-sciatic nerve block. The purpose of this investigation was to determine whether the addition of clonidine to a femoral-sciatic nerve block would prolong the duration of sensory analgesia in groups of patients undergoing anterior cruciate ligament (ACL) reconstruction. This prospective, randomized, double-blind investigation was performed on 64 subjects undergoing ACL reconstruction. Patients were assigned randomly to receive a femoral-sciatic nerve block using 30 mL of 0.5% bupivacaine with 1:200,000 epinephrine (control group) or 30 mL of 0.5% bupivacaine with 1:200,000 epinephrine and 1 microg/kg of clonidine (experimental group). Variables measured included demographics, timed pain intensity measurements, postoperative analgesic consumption, duration of analgesia, and patient satisfaction. No significant differences were noted between groups for pain intensity scores, duration of sensory analgesia, postoperative analgesic requirements, or overall patient satisfaction. Both groups reported minimal amounts of postoperative pain and high analgesic satisfaction scores. Based on our results, we do not recommend the addition of clonidine to a femoral-sciatic nerve block when given to facilitate postoperative analgesia in patients undergoing ACL reconstruction.
Tran, De Q H; González, Andrea P; Bernucci, Francisca; Pham, Kevin; Finlayson, Roderick J
In this prospective, randomized, observer-blinded trial, we compared ultrasound-guided subparaneural popliteal sciatic nerve blocks performed either at or proximal to the neural bifurcation (B). We hypothesized that the total anesthesia-related time (sum of performance and onset times) would be decreased with the prebifurcation (PB) technique. Ultrasound-guided posterior popliteal sciatic nerve block was performed in 68 patients. All subjects received an identical volume (30 mL) and mix of local anesthetic agent (1% lidocaine-0.25% bupivacaine-5 µg/mL epinephrine). In the PB group, the local anesthetic solution was deposited at the level of the common sciatic trunk, just distal to the intersection between its circular and elliptical sonographic appearances, inside the paraneural sheath. In the B group, the injection was performed inside the sheath between the tibial and peroneal divisions. A blinded observer recorded the success rate (complete tibial and peroneal sensory block at 30 minutes) and onset time. The performance time, number of needle passes, and adverse events (paresthesia, neural edema) were also recorded. All subjects were contacted 7 days after the surgery to inquire about the presence of persistent numbness or motor deficit. Both techniques resulted in comparable success rates (85%-88%; 95% confidence interval [CI] of the intergroup difference, -14% to 19%) and required similar performance times (8.1 minutes; 95% CI of the difference, -1.65 to 1.71 minutes), onset times (15.0-17.7 minutes; 95% CI of the difference, -7.65 to 2.31 minutes), and total anesthesia-related times (23.4-26.0 minutes; 95% CI of the difference, -7.83 to 2.74 minutes). The number of needle passes and incidence of paresthesia (25%-34%) were also similar between the 2 groups. Sonographic neural swelling was detected in 2 and 3 subjects in the PB and B groups, respectively. In all 5 cases, the needle was carefully withdrawn and the injection completed uneventfully. Patient
Lambert, Elisabeth; Schlaich, Markus
Decreased blood flow supply to the kidneys known as renal ischemia/reperfusion is a common occurrence during various clinical and surgical settings. This remains highly concerning as it is a major cause of acute kidney injury (AKI). The kidneys have a rich supply of efferent and afferent sympathetic nerves playing a crucial physiological role in regulation of renal function. Studies in animal models of renal ischemia/reperfusion injury have indicated that very early during an ischemic event, the sympathetic nerves are activated and in concert with decreased nitric oxide availability, increased angiotensin II and several other molecules results in renal damage. Renal sympathetic inhibition or denervation seems to prevent or decrease some of the renal damage induced by ischemia/reperfusion injury but the evidence at present is based on animal studies and remains to be confirmed in the clinical setting. Remote ischemic preconditioning (IPC) has gained a lot of interest as a strategy to limit ischemia/reperfusion damage with some recent evidence suggesting that intact sympathetic nerves may be relevant in mediating protective effects. In this article, we review the experimental studies and emerging clinical studies that have investigated the role of sympathetic nerves following ischemia/reperfusion injury and studies exploring the role of sympathetic nerves in IPC and preventing tissue dysfunction induced by renal ischemia/reperfusion. Copyright © 2017 Elsevier B.V. All rights reserved.
Walocko, Frances M.; Khouri, Roger K.; Urbanchek, Melanie G.; Levi, Benjamin; Cederna, Paul S.
Introduction This review summarizes current understanding about the role of adipose-derived tissues in peripheral nerve regeneration and discusses potential advances that would translate this approach into the clinic. Methods We searched PubMed for in vivo, experimental studies on the regenerative effects of adipose-derived tissues on peripheral nerve injuries. We summarized the methods and results for the 42 experiments. Results Adipose-derived tissues enhanced peripheral nerve regeneration in 86% of the experiments. Ninety-five percent evaluated purified, cultured, or differentiated adipose tissue. These approaches have regulatory and scaling burdens, restricting clinical usage. Only one experiment tested the ability of adipose tissue to enhance nerve regeneration in conjunction with nerve autografts, the clinical gold standard. Conclusion Scientific studies illustrate that adipose-derived tissues enhance regeneration of peripheral nerves. Before this approach achieves clinical acceptance, fat processing must become automated and regulatory approval achieved. Animal studies using whole fat grafts are greatly needed for clinical translation. PMID:26773850
Bauer, Maria; Wang, Lu; Onibonoje, Olusegun K.; Parrett, Chad; Sessler, Daniel I.; Mounir-Soliman, Loran; Zaky, Sherif; Krebs, Viktor; Buller, Leonard T.; Donohue, Michael C.; Stevens-Lapsley, Jennifer E.; Ilfeld, Brian M.
Background Whether decreasing the local anesthetic concentration during a continuous femoral nerve block results in less quadriceps weakness remains unknown. Methods Preoperatively, bilateral femoral perineural catheters were inserted in patients undergoing bilateral knee arthroplasty (n = 36) at a single clinical center. Postoperatively, right-sided catheters were randomly assigned to receive perineural ropivacaine of either 0.1% (basal 12 mL/h; bolus 4 mL) or 0.4% (basal 3 mL/h; bolus 1 mL), with the left catheter receiving the alternative concentration/rate in an observer- and subject-masked fashion. The primary endpoint was the maximum voluntary isometric contraction of the quadriceps femoris muscles the morning of postoperative day 2. Equivalence of treatments would be concluded if the 95% confidence interval for the difference fell within the interval of −20% to 20%. Secondary endpoints included active knee extension, passive knee flexion, tolerance to cutaneous electrical current applied over the distal quadriceps tendon, dynamic pain scores, opioid requirements, and ropivacaine consumption. Results Quadriceps maximum voluntary isometric contraction for limbs receiving 0.1% ropivacaine was a mean (SD) of 13 (8) N·m, versus 12 (8) N·m for limbs receiving 0.4% [intra-subject difference of 3 (40) percentage points; 95% CI −10 to 17; p = 0.63]. Because the 95% confidence interval fell within prespecified tolerances, we conclude that the effect of the two concentrations were equivalent. Similarly, there were no statistically significant differences in secondary endpoints. Conclusions For continuous femoral nerve blocks, we found no evidence that local anesthetic concentration and volume influence block characteristics, suggesting that local anesthetic dose (mass) is the primary determinant of perineural infusion effects. PMID:22293719
Pavoni, Vittorio; Gianesello, Lara; Martinelli, Cristiana; Horton, Andrew; Nella, Alessandra; Gori, Gabriele; Simonelli, Martina; De Scisciolo, Giuseppe
The aim of this study was to evaluate the efficacy of sugammadex in reversing profound rocuronium-induced neuromuscular block at the laryngeal adductor muscles using motor-evoked potentials (mMEPs). A prospective observational study. University surgical center. Twenty patients with American Society of Anesthesiologists physical class I-II status who underwent propofol-remifentanil anesthesia for the surgery of the thyroid gland. Patients were enrolled for reversal of profound neuromuscular block (sugammadex 16 mg/kg, 3 minutes after rocuronium 1.2 mg/kg). To prevent laryngeal nerve injury during the surgical procedures, all patients underwent neurophysiologic monitoring using mMEPs from vocal muscles. At the same time, the registration of TOF-Watch acceleromyograph at the adductor pollicis muscle response to ulnar nerve stimulation was performed; recovery was defined as a train-of-four (TOF) ratio ≥0.9. After injection of 16 mg/kg of sugammadex, the mean time to recovery of the basal mMEPs response at the laryngeal adductor muscles was 70 ± 18.2 seconds. The mean time to recovery of the TOF ratio to 0.9 was 118 ± 80 seconds. In the postoperative period, 12 patients received follow-up evaluation of the vocal cords and no lesions caused by the surface laryngeal electrode during electrophysiological monitoring were noted. Recovery from profound rocuronium-induced block on the larynx is fast and complete with sugammadex. In urgent scenarios, "early" extubation can be performed, even with a TOF ratio ≤0.9. However, all procedures to prevent postoperative residual curarization should still be immediately undertaken. Copyright © 2016 Elsevier Inc. All rights reserved.
Álvarez, Nora Elizabeth Rojas; Ledesma, Rosemberg Jairo Gomez; Hamaji, Adilson; Hamaji, Marcelo Waldir Mian; Vieira, Joaquim Edson
Knee arthroplasty leads to postoperative pain. This study compares analgesia and postoperative bleeding achieved by intrathecal morphine with a continuous femoral plus single-shot sciatic nerve block. A randomized non-blinded clinical trial enrolled patients aged over 18 years old, ASA I to III who underwent total knee arthroplasty. All patients underwent spinal anesthesia with isobaric bupivacaine, 20 mg. One group received 100 mcg of intrathecal morphine (M group), and the other received a femoral nerve block by continuous infusion plus a "single shot" block of the sciatic nerve at the end of the surgery (FI group). Pain score from verbal numeric rating scale (VNRS) and morphine consumption during the first 72 h, as well as motor blockade, adverse effects, and postoperative bleeding were recorded. Analysis of variance of repeated measures with Bonferroni post-test, t-test and Fisher exact test were used for statistical analysis. Thirty nine patients completed the study (M = 20; FI = 19 patients) and were similar except for higher age in the FI group. Motor blockade as well as movement pain during postanesthesia care unit (PACU) staying were not different between the groups, but movement pain was significantly lower in FI group after 24 h. Postoperative bleeding (ml) was lower in FI group. Continuous femoral nerve block combined with sciatic nerve block provides effective for postoperative analgesia in patients undergoing total knee arthroplasty, with lower pain scores after 24 h and a lower incidence of adverse effects and bleeding compared to intrathecal morphine. Retrospectively registered on https://clinicaltrials.gov/ under identifier NCT02882152 , 23(rd) December, 2016.
Wachter, Nikolaus Johannes; Mentzel, Martin; Krischak, Gert D; Gülke, Joachim
In the assessment of hand and upper limb function, grip strength is of the major importance. The measurement by dynamometers has been established. In this study, the effect of a simulated ulnar nerve lesion on different grip force measurements was evaluated. In 25 healthy volunteers, grip force measurement was done by the JAMAR dynamometer (Fabrication Enterprises Inc, Irvington, NY) for power grip and by a pinch strength dynamometer for tip pinch strength, tripod grip, and key pinch strength. A within-subject research design was used in this prospective study. Each subject served as the control by preinjection measurements of grip and pinch strength. Subsequent measurements after ulnar nerve block were used to examine within-subject change. In power grip, there was a significant reduction of maximum grip force of 26.9% with ulnar nerve block compared with grip force without block (P < .0001). Larger reductions in pinch strength were observed with block: 57.5% in tip pinch strength (P < .0001), 61.0% in tripod grip (P < .0001), and 58.3% in key pinch strength (P < .0001). The effect of the distal ulnar nerve block on grip and pinch force could be confirmed. However, the assessment of other dimensions of hand strength as tip pinch, tripod pinch and key pinch had more relevance in demonstrating hand strength changes resulting from an distal ulnar nerve lesion. The measurement of tip pinch, tripod grip and key pinch can improve the follow-up in hand rehabilitation. II. Copyright © 2017 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.
Haghgoo, Roza; Taleghani, Ferial
Background: Inferior alveolar nerve block is a common technique for anesthesia of the primary mandibular molars. A number of disadvantages have been shown to be associated with this technique. Periodontal ligament (PDL) injection could be considered as an alternative to inferior alveolar nerve block. The aim of this study was to evaluate the effectiveness of PDL injection in the anesthesia of primary molar pulpotomy with mandibular block. Methods: This study was performed using a sequential double-blind randomized trial design. 80 children aged 3-7 years old who required pulpotomy in symmetrical mandibular primary molars were selected. The teeth of these children were anesthetized with periodontal injection on one side of the mandible and block on the other. Pulpotomy was performed on each patient during the same appointment. Signs of discomfort, including hand and body tension and eye movement, the verbal complaint and crying (SEM scale), were evaluated by a dental assistant who was blinded to the treatment allocation of the patients. Finally, the data were analyzed using the exact Fisher test and Pearson Chi-squared exact test. Results: Success rate was 88/75 and 91/25 in the PDL injection and nerve block groups, respectively. There was no statistically significant difference between the two techniques (P = 0.250). Conclusion: Results showed that PDL injection can be used as an alternative to nerve block in pulpotomy of the mandibular primary molars. PMID:26028895
Nusstein, John; Steinkruger, Geoffrey; Reader, Al; Beck, Mike; Weaver, Joel
The purpose of this prospective, randomized, single-blinded, crossover study was to compare the pain of a traditional 1-stage inferior alveolar nerve (IAN) block injection to a 2-stage IAN block technique. Using a crossover design, 51 subjects randomly received, in a single-blinded manner, either the traditional IAN block or the 2-stage IAN block in 2 appointments spaced at least 1 week apart. For the 2-stage injection, the needle was inserted submucosally and 0.4 mL of 2% lidocaine with epinephrine was slowly given over 1 minute. After 5 minutes, the needle was reinserted and advanced to the target site (needle placement), and 1.8 mL of 2% lidocaine with epinephrine was deposited. For the traditional IAN block, following needle penetration, the needle was advanced while depositing 0.4 mL of 2% lidocaine with epinephrine (needle placement) and then 1.8 mL of 2% lidocaine with epinephrine was deposited at the target site. A Heft-Parker visual analogue scale was used to measure the pain of needle insertion, needle placement, and anesthetic solution deposition. There were no significant differences, as analyzed by Wilcoxon matched-pairs signed-ranks test, between needle insertion and solution deposition for the 2 techniques in men or women. However, there was significantly less pain with the 2-stage injection for needle placement in women. In conclusion, the 2-stage injection significantly reduced the pain of needle placement for women when compared to the traditional IAN technique. PMID:17177591
Duan, Yuanli; Haugabook, Sharie J; Sahley, Christie L; Muller, Kenneth J
Migration and accumulation of microglial cells at sites of injury are important for nerve repair. Recent studies on the leech central nervous system (CNS), in which synapse regeneration is successful, have shown that nitric oxide (NO) generated immediately after injury by endothelial nitric oxide synthase (eNOS) stops migrating microglia at the lesion. The present study obtained results indicating that NO may act earlier, on microglia migration, and aimed to determine mechanisms underlying NO's effects. Injury induced cGMP immunoreactivity at the lesion in a pattern similar to that of eNOS activity, immunoreactivity, and microglial cell accumulation, which were all focused there. The soluble guanylate cyclase (sGC) inhibitor methylene blue (MB) at 60 microM abolished cGMP immunoreactivity at lesions and blocked microglial cell migration and accumulation without interfering with axon conduction. Time-lapse video microscopy of microglia in living nerve cords showed MB did not reduce cell movement but reduced directed movement, with significantly more cells moving away from the lesion or reversing direction and fewer cells moving toward the lesion. The results indicate a new role for NO, directing the microglial cell migration as well as stopping it, and show that NO's action may be mediated by cGMP. Copyright 2003 Wiley Periodicals, Inc.
Finlayson, Roderick J; Etheridge, John-Paul B; Vieira, Lucy; Gupta, Gaurav; Tran, De Q H
Third occipital nerve block (TONB) is commonly used in the diagnosis and treatment of upper neck pain and cervicogenic headaches. Although fluoroscopy is the current imaging standard for TONB, ultrasound (US) guidance offers a promising, radiation-free alternative. In this randomized, observer-blinded trial, we compared the 2 imaging modalities. Our research hypothesis was that US guidance would result in a shorter performance time. Forty patients undergoing TONB were randomized to fluoroscopy or US guidance. A mixture of local anesthetic and radiographic contrast was injected in both groups. The primary outcome was performance time. Secondary outcomes included success rate, pain levels before and after block, area of sensory hypoesthesia, quality of the block (assessed by electrical perceptual threshold), and procedure-related complications. Ultrasound guidance was associated with a significantly shorter performance time (212.8 vs 396.5 seconds; P = 0.000) and fewer needle passes (2 vs 6; P = 0.000). Both imaging modalities, however, resulted in similar success rates (95%-100%). Furthermore, no intergroup differences were found in preblock and postblock pain scores. In both groups, TONB produced hypoesthesia that was most profound in the suboccipital region. In the fluoroscopy group, C2-C3 intra-articular spread of radiographic contrast and vascular breach were noted in 15% and 10% of patients, respectively. In contrast, no adverse events occurred with US guidance. Fluoroscopy and US guidance provide similar success rates for TONB. However, ultrasonography is associated with improved efficiency (decreased performance time, fewer needle passes).
Cuadrado, María L; Aledo-Serrano, Ángel; López-Ruiz, Pedro; Gutiérrez-Viedma, Álvaro; Fernández, Cristina; Orviz, Aida; Arias, José A
Background Presently, there is no evidence to guide the acute treatment of migraine aura. We aimed to describe the effect of greater occipital nerve (GON) anaesthetic block as a symptomatic treatment for long-lasting (prolonged or persistent) migraine aura. Methods Patients who presented with migraine aura lasting > 2 hours were consecutively recruited during one year at the Headache Unit and the Emergency Department of a tertiary hospital. All patients underwent a bilateral GON block with bupivacaine 0.5%. Patients were followed up for 24 hours. Results A total of 22 auras were treated in 18 patients. Auras consisted of visual ( n = 13), visual and sensory ( n = 4) or sensory symptoms alone ( n = 5). Eleven episodes met diagnostic criteria for persistent aura (>1 week) without infarction. The response was complete without early recurrence in 11 cases (50%), complete with recurrence in < 24 hours in two cases (9.1%), and partial with ≥ 50% improvement in six cases (27.3%). Complete responses without recurrence were more common in cases with prolonged auras lasting < 1 week than in those with persistent auras (72.7% vs. 27.3%; p = 0.033). Conclusions GON block could be an effective symptomatic treatment for prolonged or persistent migraine aura. Randomised controlled trials are still required to confirm these results.
Phero, James A; Nelson, Blake; Davis, Bobby; Dunlop, Natalie; Phillips, Ceib; Reside, Glenn; Tikunov, Andrew P; White, Raymond P
Outcomes for peak blood levels were assessed for buffered 2% lidocaine with 1:100,000 epinephrine compared with non-buffered 2% lidocaine with 1:100,000 epinephrine. In this institutional review board-approved prospective, randomized, double-blinded, crossover trial, the clinical impact of buffered 2% lidocaine with 1:100,000 epinephrine (Anutra Medical, Research Triangle Park, Cary, NC) was compared with the non-buffered drug. Venous blood samples for lidocaine were obtained 30 minutes after a mandibular nerve block with 80 mg of the buffered or unbuffered drug. Two weeks later, the same subjects were tested with the alternate drug combinations. Subjects also reported on pain on injection with a 10-point Likert-type scale and time to lower lip numbness. The explanatory variable was the drug formulation. Outcome variables were subjects' peak blood lidocaine levels, subjective responses to pain on injection, and time to lower lip numbness. Serum lidocaine levels were analyzed with liquid chromatography-mass spectrometry. Statistical analyses were performed using Proc TTEST (SAS 9.3; SAS Institute, Cary, NC), with the crossover option for a 2-period crossover design, to analyze the normally distributed outcome for pain. For non-normally distributed outcomes of blood lidocaine levels and time to lower lip numbness, an assessment of treatment difference was performed using Wilcoxon rank-sum tests with Proc NPAR1WAY (SAS 9.3). Statistical significance was set at a P value less than .05 for all outcomes. Forty-eight percent of subjects were women, half were Caucasian, 22% were African American, and 13% were Asian. Median age was 21 years (interquartile range [IQR], 20-22 yr), and median body weight was 147 lb (IQR, 130-170 lb). Median blood levels (44 blood samples) at 30 minutes were 1.19 μg/L per kilogram of body weight. Mean blood level differences of lidocaine for each patient were significantly lower after nerve block with the buffered drug compared with the
De Vlamynck, Caroline; Vlaminck, Lieven; Hauspie, Stijn; Saunders, Jimmy; Gasthuys, Frank
The aim of this study was to evaluate the clinical effects of a femoral nerve block via a dorsal paralumbar injection in healthy calves and calves suffering from spastic paresis. Based on bony landmarks and using ultrasound guidance, the femoral nerves of eight healthy calves were blocked bilaterally with a 4% procaine solution containing blue dye. In 11/16 nerve blocks, paralysis of the quadriceps muscle was obtained after dorsal paralumbar injection. Paralysis was total in 8/16 cases. The injection site was confirmed by post mortem dissection, and in 12/16 cases, the blue dye was found <2mm from the nerve. Clinical use of the technique was then demonstrated in two cases of atypical bovine spastic paresis. In such calves an objective diagnostic tool is required to identify those calves which are suitable for partial tibial neurectomy. The femoral nerve block used in this study has the potential to be such a method and can be used to establish the involvement of the quadriceps femoris in calves suffering from the quadriceps or mixed presentation form of spastic paresis. Copyright © 2012 Elsevier Ltd. All rights reserved.
Jeon, Younghoon; Kim, Saeyoung
The great auricular nerve can be damaged by the neck surgery, tumor, and long-time pressure on the neck. But, great auricular neuralgia is very rare condition. It was managed by several medication and landmark-based great auricular nerve block with poor prognosis. A 25-year-old man presented with a pain in the left lateral neck and auricle. He was diagnosed with great auricular neuralgia. His pain was not reduced by medication. Therefore, the great auricular nerve block with local anesthetics and steroid was performed under ultrasound guidance. Ultrasound guided great auricular nerve block alleviated great auricular neuralgia. This medication-resistant great auricular neuralgia was treated by the ultrasound guided great auricular nerve block with local anesthetic agent and steroid. Therefore, great auricular nerve block can be a good treatment option of medication resistant great auricular neuralgia.
Kikuchi, Masaru; Takaki, Shunsuke; Nomura, Takeshi; Goto, Takahisa
Pectoral nerve block (PECS block) is first reported by Blanco et al, and mainly used for analgesia for breast surgery in Japan. However, the spread of PECS block is unclear. Ultrasound guided PECS I and II blocks were performed in a cadaver, and the cadaver was dissected for evaluation of the spread of coloring matter. The coloring matter by PECS I block was spread to the axillary region between the major and minor pectoral muscles, while PECS II block remained over the fascia of the serratus muscle from mid-clavicular line to middle axillary line. Two possible routes to the axillary region by PECS I include: dorsal to the pectoral minor muscle through the clavipectoral fascia, and over the pectoral minor muscle to the axillary sheath. Our cadaveric evaluation suggests that PECS I block produces more analgesia of the axillary region than PECS II. Further evaluation is needed in more cadavers.
Hwang, Eun Gu; Lee, Yunjung
Controlling pain in patients with fractured ribs is essential for preventing secondary complications. Conventional medications that are administered orally or by using injections are sufficient for the treatment of most patients. However, additional aggressive pain control measures are needed for patients whose pain cannot be controlled effectively as well as for those in whom complications or a transition to chronic pain needs to be prevented. In this study, we retrospectively analyzed the medical records of patients in our hospital to identify the efficacy and characteristics of intercostal nerve block (ICNB), as a pain control method for rib fractures. Although ICNB, compared to conventional methods, showed dramatic pain reduction immediately after the procedure, the pain control effects decreased over time. These findings suggest that the use of additional pain control methods (e.g. intravenous patient-controlled analgesia and/or a fentanyl patch) is recommended for patients in who the pain level increases as the ICNB efficacy decreases.
Ezirganli, Seref; Kazancioglu, Hakki Oguz
Complications after administration of local anesthesia for dental procedures are well recognized. We present here 2 cases of patients with anemic areas on their faces resulting from inferior alveolar nerve block (IANB). The precise cause of this complication is unknown; however, it may be derived from anastomosis of the maxillary artery, rapid injection of local anesthetic solution, misdirection of the needle, and spread of the solution to the upper region of the mandible. Although neurologic occurrences resulting from IANB are rare, dentists should keep in mind that certain dental procedures such as administering IANB could cause anemic areas on the face. Henceforth, dentists should consider the possibility of anemia after administration of IANB and pay attention to avoid complications during the procedure.
Ajmal, Muhammad; Power, Susan; Smith, Tim; Shorten, George D
To apply ergonomic task analysis to the performance of ultrasound-guided (US-guided) femoral nerve block (FNB) in an acute hospital setting. Pilot prospective observational study. Orthopedic operating room of a regional trauma hospital. 15 anesthesiologists of various levels of experience in US-guided FNB (estimated minimum experience < 10 procedures; maximum about 50 procedures, and from basic trainees to consultants); and 15 patients (5 men and 10 women), aged 77 ± 15 (mean ± SD yrs) years. MEASUREMENTS/OBSERVATIONS: A data capture "tool", which was modified from one previously developed for ergonomic study of spinal anesthesia, was studied. Patient, operator, and heterogeneous environmental factors related to ergonomic performance of US-guided FNB were identified. The observation period started immediately before commencement of positioning the patient and ended on completion of perineural injection. Data were acquired using direct observations, photography, and application of a questionnaire. The quality of ergonomic performance was generally suboptimal and varied greatly among operators. Eight (experience < 10 procedures) of 15 operators excessively rotated their head, neck, and/or back to visualize the image on the ultrasound machine. Eight operators (experience < 10 procedures) performed the procedure with excessive thoracolumbar flexion. Performance of US-guided FNB presents ergonomic challenges and was suboptimal during most of the procedures observed. Formal training in US-guided peripheral nerve blockade should include reference to ergonomic factors. Copyright © 2011 Elsevier Inc. All rights reserved.
El-Sharrawy, Eman; Yagiela, John A
This study was conducted on 72 American Society of Anesthesiologists class 1 patients scheduled for extraction of a mandibular third molar after inferior alveolar nerve block. Each patient was randomly administered one of the following ropivacaine concentrations: 0.75%, 0.5%, 0.375%, or 0.25% (18 patients per group). Onset of block (mean ± SD) was rapid for both 0.75% (1.4 ± 0.4 minutes) and 0.5% (1.7 ± 0.5 minutes) ropivacaine but significantly slower for the 0.375% (4.2 ± 2.5 minutes) and 0.25% (10.7 ± 3.0 minutes) concentrations. Tooth extraction was performed successfully with the 0.5% and 0.75% concentrations, and supplemental injections were not required. Second injections, however, were required with 0.375% ropivacaine. Anesthesia was unsuccessful in 13 patients given 0.25% ropivacaine even after 3 injections. The mean durations of soft tissue anesthesia were 3.3 ± 0.3 hours and 3.0 ± 0.3 hours for the 0.75% and 0.5% concentrations, but significantly shorter with more dilute concentrations. The duration of analgesia showed a similar pattern, with the 0.75% and 0.5% concentrations producing prolonged analgesia of 6.0 ± 0.4 hours and 5.6 ± 0.4 hours. These results indicate that 0.5% and 0.75% concentrations were effective for intraoral nerve blockade, with both a rapid onset and prolonged duration of pain control. PMID:16722277
El-Sharrawy, Eman; Yagiela, John A
This study was conducted on 72 American Society of Anesthesiologists class 1 patients scheduled for extraction of a mandibular third molar after inferior alveolar nerve block. Each patient was randomly administered one of the following ropivacaine concentrations: 0.75%, 0.5%, 0.375%, or 0.25% (18 patients per group). Onset of block (mean +/- SD) was rapid for both 0.75% (1.4 +/- 0.4 minutes) and 0.5% (1.7 +/- 0.5 minutes) ropivacaine but significantly slower for the 0.375% (4.2 +/- 2.5 minutes) and 0.25% (10.7 +/- 3.0 minutes) concentrations. Tooth extraction was performed successfully with the 0.5% and 0.75% concentrations, and supplemental injections were not required. Second injections, however, were required with 0.375% ropivacaine. Anesthesia was unsuccessful in 13 patients given 0.25% ropivacaine even after 3 injections. The mean durations of soft tissue anesthesia were 3.3 +/- 0.3 hours and 3.0 +/- 0.3 hours for the 0.75% and 0.5% concentrations, but significantly shorter with more dilute concentrations. The duration of analgesia showed a similar pattern, with the 0.75% and 0.5% concentrations producing prolonged analgesia of 6.0 +/- 0.4 hours and 5.6 +/- 0.4 hours. These results indicate that 0.5% and 0.75% concentrations were effective for intraoral nerve blockade, with both a rapid onset and prolonged duration of pain control.
Dun, Xin-Peng; Parkinson, David B.
Netrin-1 was the first axon guidance molecule to be discovered in vertebrates and has a strong chemotropic function for axonal guidance, cell migration, morphogenesis and angiogenesis. It is a secreted axon guidance cue that can trigger attraction by binding to its canonical receptors Deleted in Colorectal Cancer (DCC) and Neogenin or repulsion through binding the DCC/Uncoordinated (Unc5) A–D receptor complex. The crystal structures of Netrin-1/receptor complexes have recently been revealed. These studies have provided a structure based explanation of Netrin-1 bi-functionality. Netrin-1 and its receptor are continuously expressed in the adult nervous system and are differentially regulated after nerve injury. In the adult spinal cord and optic nerve, Netrin-1 has been considered as an inhibitor that contributes to axon regeneration failure after injury. In the peripheral nervous system, Netrin-1 receptors are expressed in Schwann cells, the cell bodies of sensory neurons and the axons of both motor and sensory neurons. Netrin-1 is expressed in Schwann cells and its expression is up-regulated after peripheral nerve transection injury. Recent studies indicated that Netrin-1 plays a positive role in promoting peripheral nerve regeneration, Schwann cell proliferation and migration. Targeting of the Netrin-1 signaling pathway could develop novel therapeutic strategies to promote peripheral nerve regeneration and functional recovery. PMID:28245592
Liao, Chung-Ping; Pradhan, Sanjay; Chen, Zhiguo; Patel, Amish J.; Booker, Reid C.; Le, Lu Q.
Deregulation of RAS signaling in Neurofibromatosis type 1 (NF1) results in the development of multiple neurofibromas, complex tumor of the peripheral nerves with no effective medical treatment. There is increasing evidences that neurofibroma initiates through loss of NF1 function in the Schwann cell lineage, followed by a cascade of interactions with other cell types in the surrounding tumor microenvironment. In NF1 patients, neurofibromas always develop along peripheral nerves and do not migrate to distant organs, including the central nervous system. In this study, we sought to identify the contributions of these peripheral nerves in neurofibroma formation. Using in vivo and in vitro three-dimensional (3D) culturing system, we show that peripheral nerves are absolutely required for neurofibroma tumorigenesis and report a novel 3D skin raft culture system for neurofibroma formation in vitro to decipher tumor pathogenesis. This interaction between neoplastic Schwann cells and their surrounding neural microenvironment has important implications for understanding early cellular events that dictate tumorigenesis. It also provides fertile ground for the elucidation of intrinsic and extrinsic factors within the nerve microenvironment that likely play essential roles in neurofibroma development and, therefore, viable therapeutic targets in neurofibroma therapy. PMID:27517146
Karadaş, Ö; Özön, A Ö; Özçelik, F; Özge, A
This study aims to investigate the efficiency of a single and repeated greater occipital nerve (GON) block using lidocaine in the treatment of triptan-overuse headache (TOH), whose importance has increased lately. In the study, 105 consecutive subjects diagnosed with TOH were evaluated. The subjects were randomized into three groups. In Group 1 (n=35), only triptan was abruptly withdrawn. In Group 2 (n=35), triptan was abruptly withdrawn and single GON block was performed. In Group 3 (n=35), triptan was abruptly withdrawn and three-stage GON block was performed. All patients were injected bilaterally with a total amount of 5 cc 1% lidocaine in each stage. During follow-up, the number of headache days per month, the severity of pain (VAS), the number of triptans used, and hsCRP and IL-6 levels were recorded three times; in the pretreatment period, in the second month post-treatment, and in the fourth month post-treatment. They were then compared. There was a statistically significant difference in the post-treatment fourth month in comparison with the pretreatment period in Group 3 (P<.05). Compared to Group 1, the number of headache days, VAS, and decrease in triptan need in Group 3 was statistically significant compared to Group 2 (P<.05). Compared to pretreatment, in the fourth month post-treatment, both hsCRP and IL-6 levels were lower only in Group 3 (P<.05). We are of the opinion that repeated GON block in addition to the discontinuation of medication has significant efficacy for TOH cases. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Ju, Won-Kyu; Kim, Keun-Young; Noh, You Hyun; Hoshijima, Masahiko; Lukas, Thomas J; Ellisman, Mark H; Weinreb, Robert N; Perkins, Guy A
Abnormal structure and function of astrocytes have been observed within the lamina cribrosa region of the optic nerve head (ONH) in glaucomatous neurodegeneration. Glutamate excitotoxicity-mediated mitochondrial alteration has been implicated in experimental glaucoma. However, the relationships among glutamate excitotoxicity, mitochondrial alteration and ONH astrocytes in the pathogenesis of glaucoma remain unknown. We found that functional N-methyl-d-aspartate (NMDA) receptors (NRs) are present in human ONH astrocytes and that glaucomatous human ONH astrocytes have increased expression levels of NRs and the glutamate aspartate transporter. Glaucomatous human ONH astrocytes exhibit mitochondrial fission that is linked to increased expression of dynamin-related protein 1 and its phosphorylation at Serine 616. In BAC ALDH1L1 eGFP or Thy1-CFP transgenic mice, NMDA treatment induced axon loss as well as hypertrophic morphology and mitochondrial fission in astrocytes of the glial lamina. In human ONH astrocytes, NMDA treatment in vitro triggered mitochondrial fission by decreasing mitochondrial length and number, thereby reducing mitochondrial volume density. However, blocking excitotoxicity by memantine (MEM) prevented these alterations by increasing mitochondrial length, number and volume density. In glaucomatous DBA/2J (D2) mice, blocking excitotoxicity by MEM inhibited the morphological alteration as well as increased mitochondrial number and volume density in astrocytes of the glial lamina. However, blocking excitotoxicity decreased autophagosome/autolysosome volume density in both astrocytes and axons in the glial lamina of glaucomatous D2 mice. These findings provide evidence that blocking excitotoxicity prevents ONH astrocyte dysfunction in glaucomatous neurodegeneration by increasing mitochondrial fission, increasing mitochondrial volume density and length, and decreasing autophagosome/autolysosome formation. GLIA 2015;63:736-753.
Ju, Won-Kyu; Kim, Keun-Young; Noh, You Hyun; Hoshijima, Masahiko; Lukas, Thomas J; Ellisman, Mark H; Weinreb, Robert N; Perkins, Guy A
Abnormal structure and function of astrocytes have been observed within the lamina cribrosa region of the optic nerve head (ONH) in glaucomatous neurodegeneration. Glutamate excitotoxicity-mediated mitochondrial alteration has been implicated in experimental glaucoma. However, the relationships among glutamate excitotoxicity, mitochondrial alteration and ONH astrocytes in the pathogenesis of glaucoma remain unknown. We found that functional N-methyl-d-aspartate (NMDA) receptors (NRs) are present in human ONH astrocytes and that glaucomatous human ONH astrocytes have increased expression levels of NRs and the glutamate aspartate transporter. Glaucomatous human ONH astrocytes exhibit mitochondrial fission that is linked to increased expression of dynamin-related protein 1 and its phosphorylation at Serine 616. In BAC ALDH1L1 eGFP or Thy1-CFP transgenic mice, NMDA treatment induced axon loss as well as hypertrophic morphology and mitochondrial fission in astrocytes of the glial lamina. In human ONH astrocytes, NMDA treatment in vitro triggered mitochondrial fission by decreasing mitochondrial length and number, thereby reducing mitochondrial volume density. However, blocking excitotoxicity by memantine (MEM) prevented these alterations by increasing mitochondrial length, number and volume density. In glaucomatous DBA/2J (D2) mice, blocking excitotoxicity by MEM inhibited the morphological alteration as well as increased mitochondrial number and volume density in astrocytes of the glial lamina. However, blocking excitotoxicity decreased autophagosome/autolysosome volume density in both astrocytes and axons in the glial lamina of glaucomatous D2 mice. These findings provide evidence that blocking excitotoxicity prevents ONH astrocyte dysfunction in glaucomatous neurodegeneration by increasing mitochondrial fission, increasing mitochondrial volume density and length, and decreasing autophagosome/autolysosome formation. PMID:25557093
Frassanito, Luciano; Zanfini, Bruno A; Pitoni, Sara; Germini, Paolo; Del Vicario, Miryam; Draisci, Gaetano
Ultrasound-guided (USG) ilioinguinal/iliohypogastric nerve (II/IHN) block is a widely validated anesthetic technique for inguinal herniorrhaphy. As the spermatic cord, scrotum, and adjacent thigh receive sensory innervation from the genital branch of genitofemoral nerve (GFN), the addition of GFN block has been suggested to improve the quality of perioperative anesthesia and analgesia. The aim of this study is to compare GFN block plus II/IHN block with II/IHN block alone for intraoperative anesthesia and post-operative pain management. We enrolled 80, ASA I-III, male adults scheduled for elective open herniorrhaphy. Patients were randomized to receive either USG II/IHN plus GFN block (Case Group) or USG II/IHN block alone (Control Group). The outcome measures were the assessment of postoperative VAS scores on coughing and the adequacy of anesthesia, measured with intraoperative requirement for extra local anesthetic (LA) infiltration and number of patients needing systemic sedation. The requirement of intraoperative additional doses of LA was significantly lower in the Case Group (median LA volume administered by the surgeon: 13.8 ± 5.6 ml vs 20.7 ± 9.1 ml, p<0.05). Two patients in the Control Group needed systemic sedation. VAS scores at 15mins, 30 mins, 1h, 2h, pre-discharge, 24h were significantly lower in the Case Group (p<0.005). Four cases of femoral nerve block were reported, 3 in the Control Group, 1 in the Case Group (2.2% vs 7.7%, p>0.05). The combination of GFN block and II/IHN block is associated with lower postoperative VAS scores and lower doses of intraoperative additional LA.
Introduction Persistent hiccups can be more than a simple and short-lived nuisance and therefore sometimes call for serious consideration. Hiccupping episodes that last only a few minutes may be annoying, but persistent hiccups may initiate many major complications. Case presentation A 72-year-old Caucasian man with spinal stenosis presented for L4-5 laminectomy under spinal anesthesia. The surgery and anesthesia, as well as the perioperative period, passed without any incident, except for persistent postoperative hiccups not responding to conservative and pharmacological treatment. Hiccups resulted in a prolonged hospital stay as they lasted until the seventh postoperative day. On that day, a right-sided ultrasound-guided phrenic nerve block with 5 ml of bupivacaine 5 mg/ml with epinephrine was performed successfully with a single-injection technique. Ten minutes after the procedure the hiccups vanished and a partial sensomotoric block of his right shoulder developed. No adverse effect occurred; our patient could be discharged on the same day and the hiccups did not return. Conclusion Ultrasound provides us with non-invasive information regarding anatomy and allows anesthesiologists to visualize needle insertion, to identify the exact location of the injected solution and to avoid such structures as arteries or veins. As such, this method should be actively utilized. In cases where both pharmacological and non-pharmacological treatments prove to be ineffective when treating persistent hiccups, a single-shot ultrasound-guided technique should be considered before the patient becomes exhausted. PMID:21968133
Marš, Tomaž; King, Michael P; Miranda, Armand F; Grubič, Zoran
In vitro innervated human muscle is the only experimental model to study synaptogenesis of the neuromuscular junction in humans. Cultured human muscle never contracts spontaneously but will if innervated and therefore is a suitable model to study the effects of specific neural factors on the formation of functional neuromuscular contacts. Here, we tested the hypothesis that nerve derived factor agrin is essential for the formation of functional synapses between human myotubes and motoneurons growing from the explant of embryonic rat spinal cord. Agrin actions were blocked by heparin and the formation of functional neuromuscular contacts was quantitated. At a heparin concentration of 25 μg/ml, the number of functional contacts was significantly reduced. At higher concentrations, formation of such contacts was blocked completely. Except at the highest heparin concentrations (150 μg/ml) neuronal outgrowth was normal indicating that blockade of neuromuscular junction formation was not due to neuronal dysfunction. Our results are in accord with the concept that binding of neural agrin to the synaptic basal lamina is essential for the formation of functional neuromuscular junctions in the human muscle.
Mars, T; King, M P; Miranda, A F; Grubic, Z
In vitro innervated human muscle is the only experimental model to study synaptogenesis of the neuromuscular junction in humans. Cultured human muscle never contracts spontaneously but will if innervated and therefore is a suitable model to study the effects of specific neural factors on the formation of functional neuromuscular contacts. Here, we tested the hypothesis that nerve derived factor agrin is essential for the formation of functional synapses between human myotubes and motoneurons growing from the explant of embryonic rat spinal cord. Agrin actions were blocked by heparin and the formation of functional neuromuscular contacts was quantitated. At a heparin concentration of 25 microg/ml, the number of functional contacts was significantly reduced. At higher concentrations, formation of such contacts was blocked completely. Except at the highest heparin concentrations (150 microg/ml) neuronal outgrowth was normal indicating that blockade of neuromuscular junction formation was not due to neuronal dysfunction. Our results are in accord with the concept that binding of neural agrin to the synaptic basal lamina is essential for the formation of functional neuromuscular junctions in the human muscle.
Heywang-Köbrunner, S H; Amaya, B; Okoniewski, M; Pickuth, D; Spielmann, R P
Obturator nerve blocks (ONB) have been performed by anaesthesiologists mainly to eliminate the obturator reflex during transurethral resections. An effect on hip pain has also been described. However, being a time-consuming and operator-dependent procedure if performed manually, it has not been widely used for chronic hip pain. The purpose of this pilot study was to check whether CT guidance could improve reproducibility of the block (= immediate effect) and to test its potential value for treatment of chronic hip pain. Fifteen chronically ill patients with osteoarthritis underwent a single ONB. Sixteen millilitres of Lidocaine 1% mixed with 2 ml Iopramide was injected into the obturator canal. The patients were followed up to 9 months after the intervention. With a single injection pain relief was achieved for 1-8 weeks in 7 of 15 patients. Excellent pain relief for 3-11 months was achieved in another 4 patients. Reasons for a mid-term or even long-term effect based on a single injection of local anaesthetic are not exactly known. The CT-guided ONB is a fast, easy and safe procedure that may be useful for mid-term (weeks) and sometimes even long-term (months) treatment of hip pain.
Medeiros Venancio, Antonio; Ferreira-da-Silva, Francisco Walber; da Silva-Alves, Kerly Shamyra; de Carvalho Pimentel, Hugo; Macêdo Lima, Matheus; Fraga de Santana, Michele; Barreto Alves, Péricles; Batista da Silva, Givanildo; Leal-Cardoso, José Henrique; Marchioro, Murilo
The racemate linalool and its levogyrus enantiomer [(-)-LIN] are present in many essential oils and possess several pharmacological activities, such as antinociceptive and anti-inflammatory. In this work, the effects of essential oil obtained from the cultivation of the Ocimum basilicum L. (EOOb) derived from Germplasm Bank rich in (-)-LIN content in the excitability of peripheral nervous system were studied. We used rat sciatic nerve to investigate the EOOb and (-)-LIN effects on neuron excitability and the extracellular recording technique was used to register the compound action potential (CAP). EOOb and (-)-LIN blocked the CAP in a concentration-dependent way and these effects were reversible after washout. EOOb blocked positive amplitude of 1st and 2nd CAP components with IC50 of 0.38 ± 0.2 and 0.17 ± 0.0 mg/mL, respectively. For (-)-LIN, these values were 0.23 ± 0.0 and 0.13 ± 0.0 mg/mL. Both components reduced the conduction velocity of CAP and the 2nd component seems to be more affected than the 1st component. In conclusion EOOb and (-)-LIN inhibited the excitability of peripheral nervous system in a similar way and potency, revealing that the effects of EOOb on excitability are due to the presence of (-)-LIN in the essential oil.
Basat, H Çağdaş; Uçar, D Hakan; Armangil, Mehmet; Güçlü, Berk; Demirtaş, Mehmet
Postoperative pain management is the part of shoulder surgery to improve patient satisfaction, start rehabilitation process rapidly and decrease for hospital stay. Various treatment modalities have been used for pain management, but they have some limitations, side effects and risks. Throughout intraoperative and postoperative period, nerve blocks have been used more popularly than others because of efficacy. For the regional nerve block, local anesthetic should be infiltrated close to the nerve for maximum effect. Consequently, aim of this study was to evaluate analgesic efficacy when catheters are placed with assistance of arthroscope to block suprascapular and axillary nerves in patients undergoing arthroscopic repair of rotator cuff under general anesthesia. 24 patients (5 males, 19 females; mean age: 54.3 years) who underwent arthroscopic repair of rotator cuff between June 2014 and September 2014 and were catheterized to block suprascapular and axillary nerves during shoulder arthroscopy were included in the study. Clinical outcomes were assessed using visual analog scale (VAS) scores preoperatively and at 0 h, 6 h, 12 h, 18 h, 24 h, and postoperative day 2. Preoperative and postoperative 0 h, 6 h, 12 h, 18 h, 24 h, and day 2 mean VAS scores were 6.38 ± 0.77, 0.44 ± 0.42, 0.58 ± 0.42, 0.63 ± 0.40, 0.60 ± 0.44, 0.52 ± 0.42, and 1.55 ± 0.46, respectively. No statistical difference was found among 0 h, 6 h, 12 h, 18 h, and 24 h time points; however, comparison of postoperative day 2 and postoperative 0 h, 6 h, 12 h, 18h and 24 h VAS scores showed statistically significant difference (P < 0.05). All patients were discharged at the end of 24 h with no complication. The mean time (in minutes) required for blocking suprascapular nerve and axillar nerve were 14.38 ± 3.21 and 3.75 ± 0.85, respectively. These results demonstrated that blocking two nerves with arthroscopic approach was an excellent pain management method in postoperative period. Accordingly
Wachter, N J; Mentzel, M; Hütz, R; Gülke, J
In the assessment of hand and upper limb function, detecting sincerity of effort (SOE) for grip strength is of major importance to identifying feigned loss of strength. Measuring maximal grip strength with a dynamometer is very common, often combined with calculating the coefficient of variation (CV), a measure of the variation over the three grip strength trials. Little data is available about the relevance of these measurements in patients with median nerve impairment due to the heterogeneity of patient groups. This study examined the reliability of grip strength tests as well as the CV to detect SOE in healthy subjects. The power distribution of the individual fingers and the thenar was taken into account. To assess reliability, the measurements were performed in subjects with a median nerve block to simulate a nerve injury. The ability of 21 healthy volunteers to exert maximal grip force and to deliberately exert half-maximal force to simulate reduced SOE in a power grip was examined using the Jamar(®) dynamometer. The experiment was performed in a combined setting with and without median nerve block of the same subject. The force at the fingertips of digits 2-5 and at the thenar eminence was measured with a sensor glove with integrated pressure receptors. For each measurement, three trials were recorded subsequently and the mean and CV were calculated. When exerting submaximal force, the subjects reached 50-62% of maximal force, regardless of the median nerve block. The sensor glove revealed a significant reduction of force when exerting submaximal force (P1 sensor) with (P<0.032) and without median nerve block (P<0.017). An increase in CV at submaximal force was found, although it was not significant. SOE can be detected with the CV at the little finger at using a 10% cut-off (sensitivity 0.84 and 0.92 without and with median nerve block, respectively). These findings suggest low reliability of the power grip measurement with the Jamar(®) dynamometer, as
Luo, Danping; Wang, Xiaolin; He, Jiman
Acupressure is an alternative medicine methodology that originated in ancient China. Treatment effects are achieved by stimulating acupuncture points using acute pressure. Acute pressure block of the sciatic nerve is a newly reported analgesic method based on a current neuroscience concept: stimulation of the peripheral nerves increases the pain threshold. Both methods use pressure as an intervention method. Herein, we compare the methodology and mechanism of these two methods, which exhibit several similarities and differences. Acupressure entails variation in the duration of manipulation, and the analgesic effect achieved can be short-or long-term. The acute effect attained with acupressure presents a scope that is very different from that of the chronic effect attained after long-term treatment. This acute effect appears to have some similarities to that achieved with acute pressure block of the sciatic nerve, both in methodology and mechanism. More evidence is needed to determine whether there is a relationship between the two methods.
Luo, Danping; Wang, Xiaolin; He, Jiman
Acupressure is an alternative medicine methodology that originated in ancient China. Treatment effects are achieved by stimulating acupuncture points using acute pressure. Acute pressure block of the sciatic nerve is a newly reported analgesic method based on a current neuroscience concept: stimulation of the peripheral nerves increases the pain threshold. Both methods use pressure as an intervention method. Herein, we compare the methodology and mechanism of these two methods, which exhibit several similarities and differences. Acupressure entails variation in the duration of manipulation, and the analgesic effect achieved can be short-or long-term. The acute effect attained with acupressure presents a scope that is very different from that of the chronic effect attained after long-term treatment. This acute effect appears to have some similarities to that achieved with acute pressure block of the sciatic nerve, both in methodology and mechanism. More evidence is needed to determine whether there is a relationship between the two methods. PMID:23983488
Analgesic drugs are the first line of pain relief in cancer, but they should not be the only treatment offered. If nerve blocks and other destructive procedures are to be used they should be used early with conviction and persistence. They might not be being used because there are not enough doctors who can use them properly. PMID:2465046
Vettorato, Enzo; Corletto, Federico
The aim of this study was to assess retrospectively the efficacy and complication rate of hindlimb peripheral nerve blocks (PNBs) in cats. Clinical records of cats that received PNBs and underwent hindlimb orthopaedic surgery from February 2010 to October 2014 were examined. Type of PNB, type and dose of local anaesthetic used, end-expiratory fraction of isoflurane (FE'Iso) administered, additional intraoperative analgesia, incidence of hypotension, postoperative opioid requirement, postoperative contralateral limb paralysis and neurological complications at the 6 week re-examination were investigated. Eighty-nine records were retrieved but only 69 were analysed. Four combinations of PNBs were used: 34 lateral preiliac (LPI) approach to lumbar plexus (LP) associated with lumbar paravertebral approach to sciatic nerve (SN); 20 LPI-LP associated with the lateral approach to SN; three LPI-LP associated with gluteal approach to SN; 12 dorsal-paravertebral (DPV) approach to LP associated with lateral SN. Levobupivacaine was used for the majority of PNBs. The mean intraoperative FE'Iso was 1.15%; hypotension was documented in 55.1% of anaesthetics, while 31.8% of cats received fentanyl and/or ketamine intraoperatively. Postoperatively, 72.7% of cats received at least one dose of opioid, while five cats required further postoperative analgesia (ketamine constant rate infusion and/or gabapentin). No cats showed contralateral limb paralysis and neurological complications at the 6 week re-examination. No differences were found when comparing the different PNBs used. PNBs contributed to perioperative anaesthesia/analgesia in cats undergoing hindlimb orthopaedic surgery. However, the clinical relevance of intraoperative hypotension needs further investigation. © The Author(s) 2015.
Morath, Ute; Luyet, Cédric; Spadavecchia, Claudia; Stoffel, Michael H; Hatch, Garry M
To develop an ultrasound-guided technique for retrobulbar nerve block in horses, and to compare the distribution of three different volumes of injected contrast medium (CM) (4, 8 and 12 mL), with the hypothesis that successful placement of the needle within the retractor bulbi muscle cone would lead to the most effective dispersal of CM towards the nerves leaving the orbital fissure. Prospective experimental cadaver study. Twenty equine cadavers. Ultrasound-guided retrobulbar injections were performed in 40 cadaver orbits. Ultrasound visualization of needle placement within the retractor bulbi muscle cone and spread of injected CM towards the orbital fissure were scored. Needle position and destination of CM were then assessed using computerized tomography (CT), and comparisons performed between ultrasonographic visualization of orbital structures and success rate of injections (intraconal needle placement, CM reaching the orbital fissure). Higher scores for ultrasound visualization resulted in a higher success rate for intraconal CM injection, as documented on the CT images. Successful intraconal placement of the needle (22/34 orbits) resulted in CM always reaching the orbital fissure. CM also reached the orbital fissure in six orbits where needle placement was extraconal. With 4, 8 and 12 mL CM, the orbital fissure was reached in 16/34, 23/34 and 28/34 injections, respectively. The present study demonstrates the use of ultrasound for visualization of anatomical structures and needle placement during retrobulbar injections in equine orbits. However, this approach needs to be repeated in controlled clinical trials to assess practicability and effectiveness in clinical practice. © 2012 The Authors. Veterinary Anaesthesia and Analgesia. © 2012 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesiologists.
Picelli, Alessandro; Bonazza, Sara; Lobba, Davide; Parolini, Massimo; Martini, Alvise; Chemello, Elena; Gandolfi, Marialuisa; Polati, Enrico; Smania, Nicola; Schweiger, Vittorio
Hemiplegic shoulder pain is the most common pain condition after stroke. Suprascapular nerve block is an effective treatment for shoulder pain. The aim of this pilot study was to evaluate the effects of suprascapular nerve block on pain intensity, spasticity, shoulder passive range of motion, and quality of life in long-term chronic stroke patients with hemiplegic shoulder pain. Ten chronic stroke patients (over 2 years from onset) with hemiplegic shoulder pain graded ≥30 mm on the Visual Analogue Scale underwent suprascapular nerve block injection with 1 mL of 40 mg/mL methylprednisolone and 10 mL 0.5% bupivacaine hydrochloride. Main outcome was the Visual Analogue Scale evaluated before and after nerve block at 1 h, 1 week, and 1 month. Secondary outcomes were the modified Ashworth scale and the shoulder elevation, abduction, and external rotation passive range of motion evaluated before the nerve block and after 1 h as well as the American Chronic Pain Association Quality of Life Scale evaluated before and after nerve block at 1 month. The Visual Analogue Scale significantly improved after nerve block at 1 h (P = 0.005) and 1 week (P = 0.011). Significant improvements were found at 1 h after nerve block in the modified Ashworth scale (P = 0.014) and the passive range of motion of shoulder abduction (P = 0.026), flexion (P = 0.007), and external rotation (P = 0.017). The American Chronic Pain Association Quality of Life Scale significantly improved at 1 month after nerve block (P = 0.046). Our findings support the use of suprascapular nerve block for treating hemiplegic shoulder pain in long-term chronic stroke patients.
Khedkar, Sunita Milind; Bhalerao, Pradnya Milind; Yemul-Golhar, Shweta Rahul; Kelkar, Kalpana Vinod
Background: The conventional technique of ilioinguinal and iliohypogastric nerve block may be associated with drug toxicity, block failure and needs large drug volume. The ultrasound-guided (USG) nerve block enables accurate needle positioning that may reduce the chances of drug toxicity, drug dose and block failure. Aim: In this study, we compared the onset and duration of the motor and sensory nerve block, the drug volume required and time to rescue analgesic between USG and conventional technique. Settings and Design: Sixty male patients aged between 18 and 60 years, belonging to American society of Anesthesiology I-II, scheduled for inguinal hernia repair were enrolled in this prospective study and were randomly allocated into two groups of thirty each by computerized method. Materials and Methods: Group A patients received hernia block by conventional method using 0.75% ropivacaine 15 ml, and Group B patients were given the block guided by ultrasound using 0.75% ropivacaine, till the nerves were surrounded on all sides by the drug. Statistical Analysis: The data were analyzed using two independent sample t-tests for demographic and hemodynamic parameters. Nonparametric test (Mann-Whitney U-test) was used to find the significance between visual analog scale. Results: There was significantly early onset of sensory block in Group B 14.03 ± 2.82 min as compared to Group A 15.57 ± 1.52 min (P = 0.047). The onset of motor block was also earlier in Group B 19.40 ± 2.85 min as compared to Group A 20.67 ± 1.90 min. The time to rescue analgesia was more in Group B 7.22 ± 0.97 h as compared to Group A 6.80 ± 0.70 h (P = 0.062). The volume of drug required was less with ultrasound guided block. Conclusions: Ultrasound-guided hernia block thus has the advantage of early onset, less dose requirement and increase in time to rescue analgesia. PMID:26240549
Luan, Yang; Huang, Tian-bao; Gu, Xiao; Zhou, Guang-Chen; Lu, Sheng-Ming; Tao, Hua-Zhi; Liu, Bi-De; Ding, Xue-Fei
Abstract Objective: The objective of this study was to evaluate the anesthetic efficacy of periprostatic nerve block (PNB) in transrectal ultrasound (TRUS)-guided biopsy on different prostate volume. Methods: A total of 568 patients received prostate biopsy in our hospital from May 2013 to September 2015 and were retrospectively studied. All patients were divided into local anesthesia group (LAG) and nerve block group (NBG). Then each group was subdivided into 4 subgroups (20–40, 40–60, 60–100, and >100 mL groups) according to different prostate volume range. Visual analogue scale (VAS) and visual numeric scale (VNS) were used to assess the patient's pain and quantify their satisfaction. The scores and complications were compared between the groups. Results: The age and serum prostate-specific antigen (PSA) level before biopsy had no significant differences at intergroup or intragroup level. The VAS scores were significantly lower in the NBG than those in the LAG in terms of prostate volume (1 (1–2) versus 2 (1–3), 2 (1–3) versus 2 (2–4), 2 (2–3) versus 3 (2–5), 4 (3–5) versus 5 (4–7), all P < 0.05). Conversely, the VNS scores were higher in the NBG (4 (3–4) versus 3.5 (3–4), 3 (3–4) versus 3 (3–3), 3 (2–4) versus 3 (2–3), 2 (2–2) versus 1 (1–2), all P < 0.05). Patients with smaller prostate volume undergoing PNB or local anesthesia experienced significantly lower pain and higher satisfaction scores than those with large prostate. Whether in PNB or local anesthesia group, patients with large prostate volume had more chance to have hematuria, hemospermia, urinary retention than smaller one except infection (P < 0.05). Those complications had no significant differences between LAG and NBG (P > 0.05). Conclusion: Compared with local anesthesia, ultrasound-guided PNB has superior analgesic effect and equal safety, but for patients with a large prostate volume, the analgesic effect is inefficient. PMID:27428215
Jadon, Ashok; Kedia, Sunil Kumar; Dixit, Shreya; Chakraborty, Swastika
Background: Spinal anaesthesia is the preferred technique to fix fracture of the femur. Extreme pain does not allow ideal positioning for this procedure. Intravenous fentanyl and femoral nerve block are commonly used techniques to reduce the pain during position for spinal anaesthesia however; results are conflicting regarding superiority of femoral nerve block over intravenous fentanyl. Aims: We conducted this study to compare the analgesic effect provided by femoral nerve block (FNB) and intra- venous (IV) fentanyl prior to positioning for central neuraxial block in patients undergoing surgery for femur fracture. Patients and Methods: In this randomized prospective study 60 patients scheduled for fracture femur operation under spinal were included. Patients were distributed in two groups through computer generated random numbers table; Femoral nerve block group (FNB) and Intravenous fentanyl group (FENT). In FNB group patients received FNB guided by a peripheral nerve stimulator (Stimuplex; B Braun, Melsungen, AG) 5 minutes prior to positioning. 20mL, 1.5% lidocaine with adrenaline (1:200,000) was injected incrementally after a negative aspiration test. Patients in the fentanyl group received injection fentanyl 1 μg/kg IV 5 mins prior to positioning. Spinal block was performed and pain scores before and during positioning were recorded. Statistical analysis was done with Sigmaplot version-10 computer software. Student t-test was applied to compare the means and P < 0.05 was taken as significant. Results: VAS during positioning in group FNB: 0.57 ± 0.31 versus FENT 2.53 ± 1.61 (P = 0.0020). Time to perform spinal anesthesia in group FNB: 15.33 ± 1.64 min versus FENT 19.56 ± 3.09 min (P = 0.000049). Quality of patient positioning for spinal anesthesia in group FNB 2.67± 0.606 versus FENT 1.967 ± 0.85 (P = 0.000027). Patient acceptance was less in group FENT (P = 0.000031). Conclusion: Femoral nerve block provides better analgesia, patient satisfaction and
Jadon, Ashok; Kedia, Sunil Kumar; Dixit, Shreya; Chakraborty, Swastika
Spinal anaesthesia is the preferred technique to fix fracture of the femur. Extreme pain does not allow ideal positioning for this procedure. Intravenous fentanyl and femoral nerve block are commonly used techniques to reduce the pain during position for spinal anaesthesia however; results are conflicting regarding superiority of femoral nerve block over intravenous fentanyl. We conducted this study to compare the analgesic effect provided by femoral nerve block (FNB) and intra- venous (IV) fentanyl prior to positioning for central neuraxial block in patients undergoing surgery for femur fracture. In this randomized prospective study 60 patients scheduled for fracture femur operation under spinal were included. Patients were distributed in two groups through computer generated random numbers table; Femoral nerve block group (FNB) and Intravenous fentanyl group (FENT). In FNB group patients received FNB guided by a peripheral nerve stimulator (Stimuplex; B Braun, Melsungen, AG) 5 minutes prior to positioning. 20mL, 1.5% lidocaine with adrenaline (1:200,000) was injected incrementally after a negative aspiration test. Patients in the fentanyl group received injection fentanyl 1 μg/kg IV 5 mins prior to positioning. Spinal block was performed and pain scores before and during positioning were recorded. Statistical analysis was done with Sigmaplot version-10 computer software. Student t-test was applied to compare the means and P < 0.05 was taken as significant. VAS during positioning in group FNB: 0.57 ± 0.31 versus FENT 2.53 ± 1.61 (P = 0.0020). Time to perform spinal anesthesia in group FNB: 15.33 ± 1.64 min versus FENT 19.56 ± 3.09 min (P = 0.000049). Quality of patient positioning for spinal anesthesia in group FNB 2.67± 0.606 versus FENT 1.967 ± 0.85 (P = 0.000027). Patient acceptance was less in group FENT (P = 0.000031). Femoral nerve block provides better analgesia, patient satisfaction and satisfactory positioning than IV fentanyl for position during
Montserrat-Bosch, Marta; Nogueira-Magalhães, Pedro; Arnabat-Dominguez, Josep; Valmaseda-Castellón, Eduard; Gay-Escoda, Cosme
Objectives: To compare the efficacy and complication rates of two different techniques for inferior alveolar nerve blocks (IANB). Study Design: A randomized, triple-blind clinical trial comprising 109 patients who required lower third molar removal was performed. In the control group, all patients received an IANB using the conventional Halsted technique, whereas in the experimental group, a modified technique using a more inferior injection point was performed. Results: A total of 100 patients were randomized. The modified technique group showed a significantly higher onset time in the lower lip and chin area, and was frequently associated to a lingual electric discharge sensation. Three failures were recorded, 2 of them in the experimental group. No relevant local or systemic complications were registered. Conclusions: Both IANB techniques used in this trial are suitable for lower third molar removal. However, performing an inferior alveolar nerve block in a more inferior position (modified technique) extends the onset time, does not seem to reduce the risk of intravascular injections and might increase the risk of lingual nerve injuries. Key words:Dental anesthesia, inferior alveolar nerve block, lidocaine, third molar, intravascular injection. PMID:24608204
Sun, Rui-Di; Fu, Bin; Li, Cheng; Kuang, Guang-Tao; Luo, Xiao-Qing; Jiang, Jun
To study the role of proximal nerve stimulation at Erb point in the early diagnosis of Guillain-Barré syndrome (GBS) in children. Thirty-two children who were diagnosed with GBS between October 2013 and December 2014 received neurophysiological examination. Thirty healthy children were used as controls. Compound muscle action potentials and distal motor latency of the median and ulnar nerves were determined and analyzed after nerve stimulation at the wrist, elbow, and Erb point in the two groups. Moreover, F-wave latency of the median nerve and H-reflex latency of the tibial nerve were measured and analyzed in the two groups. The F-wave and H-reflex latencies were significantly longer in the patient group than in the control group (P<0.05). In thirty-two patients, the numbers of patients with abnormal amplitude, abnormal latency, and conduction block at Erb's point were 24 (75%), 22 (69%), and 20 (62%), respectively. The patient group had significantly lower amplitudes but significantly longer latencies of the ulnar and median nerves at Erb point than the control group (P<0.05). There were no significant differences in the amplitudes and latencies at the wrist and elbow between the two groups (P>0.05). The nerve stimulation at Erb point holds promise as a routine examination for the early diagnosis of GBS.
Gadsden, Jeff C; Choi, Jason J; Lin, Emily; Robinson, Allegra
Needle trauma may cause neuropathy after nerve blockade. Even without injection, nerve injury can result from forceful needle-nerve contact (NNC). High opening injection pressures (OIPs) have been associated with intrafascicular needle tip placement and nerve damage; however, the relationship between OIP and NNC is unclear. The authors conducted a prospective, observational study to define this relationship. Sixteen patients scheduled for shoulder surgery under interscalene block were enrolled if they had clear ultrasound images of the brachial plexus roots. A 22-gauge stimulating needle was inserted within 1 mm of the root, and 1-ml D5W injected at 10 ml/min by using an automated pump. OIP was monitored using an in-line pressure manometer and injections aborted if 15 psi or greater. The needle was advanced to displace the nerve slightly (NNC), and the procedure repeated. Occurrence of evoked motor response and paresthesia were recorded. Fifteen patients had at least one clearly visible root. OIP at 1 mm distance from the nerve was less than 15 psi (mean peak pressure 8.2 ± 2.4 psi) and the 1-ml injection could be completed in all but two cases (3%). In contrast, OIP during NNC was 15 psi or greater (mean peak pressure 20.9 ± 3.7 psi) in 35 of 36 injections. Aborting the injection when OIP reached 15 psi prevented commencement of injection in all cases of NNC except one. High OIP (≥15 psi) consistently detected NNC, suggesting that injection pressure monitoring may be useful in preventing injection against nerve roots during interscalene block.
Heller, A A; Shankland, W E
Local anesthesia block of the inferior alveolar nerve is routinely taught throughout dental education. This commonly used technique eliminates all somatosensory perception of the mandible, mandibular teeth, floor of the mouth, ipsilateral tongue, and all but the lateral (buccal) gingivae. Generally, the dentist or surgeon desires these structures to be anesthetized. However, in the placement of mandibular implants, it may be useful for the patient to be able to sense when the inferior alveolar nerve is in danger of being damaged, possibly producing permanent paresthesia. In this article, the technique of mandibular infiltration prior to mandibular implant placement in the mandible is discussed.
Auyong, David B; Cantor, David Asher; Green, Cynthia; Hanson, Neil A
Continuous peripheral nerve blocks offer advantages over single-injection blocks, including extended analgesia and reduction in opioid consumption. These benefits require that the perineural catheter remain intact for the duration of the planned local anesthetic infusion. Mechanical displacement of catheters, leaking, and consequent failure are known complications. The aim of this study was to evaluate continuous perineural catheter tip-to-nerve apposition in vivo over 48 hours comparing 2 different simple fixation strategies. Subjects presenting for a continuous interscalene nerve block were randomized to perineural catheter fixation with 1 of 2 types of adhesive: Dermabond (2-octylcyanoacrylate) or Mastisol (alcohol 23A, gum mastic, storax, and methyl salicylate), covered with a simple transparent dressing. The primary outcome was the evaluation of catheter-to-nerve apposition maintenance over 48 hours via both a blinded ultrasound evaluation of local anesthetic distribution and a blinded clinical assessment. Secondary outcomes included leakage at the catheter site, pain scores, opioid consumption, catheter-to-skin migration at the insertion site, and patient satisfaction. Sixty-six subjects were recruited and randomized to compare adhesive group catheter tip-to-nerve apposition on postoperative day 2 (POD 2). Within the intention-to-treat cohort, a statistically significant decrease of perineural catheter tip-to-nerve apposition in the Mastisol group (64.7%) compared with the Dermabond group (90.6%) on POD 2 (odds ratios [OR] 0.19; 95% confidence interval [CI] 0.05-0.75; P = .012) was observed. Similar results were observed on POD 1 (OR 0.19; 95% CI 0.03-1.38; P = NS) and POD 2 (OR 0.14; 95% CI 0.02-0.97; P = .008) within the as-treated cohort. Catheter leakage (OR 67; 95% CI 7.3-589) and median catheter migration difference at the skin insertion site (2.0 cm; 95% CI 0.5-2.5) were also significantly greater in the Mastisol group than in the Dermabond group from
Wang, Fen; Zhou, Yingjie; Sun, Jiajun; Yang, Chunxi
Continuous femoral nerve block (CFNB), guided by ultrasound combined nerve stimulations, offers advantages for both sides and provides effective postoperative analgesia after total knee arthroplasty (TKA). The objective of this study was to evaluate the medium-term impact of continuous femoral nerve block on knee function and quality of life in patients following TKA. This was a follow-up study. Total 168 adult patients scheduled for elective TKA were randomly allocated to receive postoperative continuous femoral nerve block guided by ultrasound combined nerve stimulator (group CFNB, n = 82) or patient-controlled epidural analgesia (group PCEA, n = 86). Quality of life, knee function, patient satisfaction, pain medication and associated adverse effects were compared at 1, 3, 6, and 12 months postoperatively. Quality of life was assessed using the Medical Outcomes Study Short Form-36 Health Survey (MOS SF-36), and clinical results were assessed using the Hospital for Special Surgery (HSS) Knee Scoring System. Patient satisfaction scores were divided into four categories. A total of 162 patients completed the 12-month follow-up. The CFNB group patients had significantly improved SF-36 scores and physical function at 1 month postoperatively (P < 0.05); the remaining seven dimensions were similar between the two groups. No differences were observed at 3, 6 or 12 months. HSS scores for the four observational time points were comparable. The CFNB group patients reported less pain; improved knee function, maximum flexion and strength; less celecoxib consumption and fewer side effects at 1 month than the PCEA group patients. The satisfaction score at 12 months decreased significantly, compared with that at 1 month in both groups (3.6 to 2.95 and 3.4 to 2.45, respectively). No difference in satisfaction score was observed between the two groups. Continuous femoral nerve block not only could provide effective postoperative analgesia but also could improve joint function and
Khairnar, Prakash; Agarwal, Munisha; Verma, Uttam Chandra; Kumar, Rakesh
Background and Aims: Patients with burns may require multiple surgeries, but poor general condition and underlying protein energy malnutrition make them unsuitable candidates for general or spinal anaesthesia. This study evaluated the role of magnesium sulphate as an adjuvant with levobupivacaine and ropivacaine used in combined femoral and lateral femoral cutaneous nerve (LFCN) blocks in burn patients with relative sparing of thigh portion. Methods: This prospective, randomised, double-blind study included 54 adult patients of 18–65 years age, undergoing split-thickness skin graft harvest from the thigh, allotted to three equal groups of 18 each. Group L patients received femoral nerve (FN) block with 15 mL of 0.5% levobupivacaine and 8 mL for LFCN block; Group LM patients received 14 mL of 0.5% levobupivacaine along with 1.0 mL of 15% magnesium sulphate for FN block, 7.5 mL of 0.5% levobupivacaine with 0.5 mL of 15% of magnesium sulphate to LFCN block and Group R patients received 15 mL of 0.5% ropivacaine for FN block and 8 mL of 0.5% ropivacaine for LFCN block. Time to block onset and complete surgical block, duration of analgesia, total analgesic dose and the overall analgesia satisfaction score were measured in the first 24 h post-operatively. Quantitative data were analysed with ANOVA and qualitative data subjected to Chi-square tests. Intergroup comparison was performed with independent t-test. Results: The duration of post-operative analgesia did not differ with the addition of magnesium (P = 0.610). Time to onset of the block was significantly decreased with the addition of magnesium (P = 0.0341), but time to complete surgical block onset was similar across the groups. Conclusion: Both ropivacaine and levobupivacaine have good perioperative analgesic efficacy. Magnesium as an analgesia adjuvant with levobupivacaine does not prolong the duration of post-operative analgesia. PMID:27601742
Dauphin, Alezandre; Lubanska-Hubert, Elizabeth; Young, J. Edward M.; Miller, John D.; Bennett, W. Frederick; Fuller, Hugh D.
Objectives To compare the efficacy of continuous extrapleural intercostal nerve block with bupivacaine 0.5% in 1:200 000 epinephrine and continuous lumbar epidural block with morphine in controlling post-thoracotomy pain and to measure serum bupivacaine concentrations during extrapleural infusion. Design A prospective, randomized, controlled trial. Setting St. Joseph’s Hospital, Hamilton, Ont., a tertiary care teaching centre. Patients Sixty-one patients booked for elective thoracotomy were randomized by sealed envelope to two groups. Interventions Group A received a continuous extrapleural intercostal nerve block with bupivacaine 0.5% in 1:200 000 epinephrine as a bolus of 0.3 mL/kg followed by an infusion of 0.1 mL/kg every hour for 72 hours. Group B received a continuous lumbar epidural block with morphine as a bolus of 70 g/kg followed by an infusion of 7 g/kg every hour for 72 hours. Main outcome measures Pain was assessed by a linear visual analogue scale (VAS) pain score. The cumulative amount of “rescue” intravenous morphine used, and serum bupivacaine concentrations were measured as secondary outcomes. Results Pain control was the same in both groups as assessed by linear VAS score (p = 0.33). The cumulative dose of intravenous morphine for supplemental analgesia was statistically significant between the groups: group A patients used more morphine than group B (p < 0.05). Accumulation of serum bupivacaine was present with no clinical toxicity. Conclusions There is no significant difference in the degree of post-thoracotomy pain control measured by the VAS score when analgesia is provided by continuous extrapleural intercostal nerve block with bupivacaine 0.5% in 1:200 000 epinephrine or lumbar epidural block with morphine. Larger amounts of rescue analgesia were used by patients in the continuous extrapleural group with bupivacaine than those in the continuous lumbar epidural block with morphine. Serum bupivacaine concentrations rise without clinical
Børglum, J; Bartholdy, A; Hautopp, H; Krogsgaard, M R; Jensen, K
We present a case with an ultrasound-guided (USG) placement of a perineural catheter beneath the transverse scapular ligament in the scapular notch to provide a continuous block of the suprascapular nerve (SSN). The patient suffered from a severe and very painful adhesive capsulitis of the left shoulder secondary to an operation in the same shoulder conducted 20 weeks previously for impingement syndrome and a superior labral anterior-posterior tear. Following a new operation with capsular release, the placement of a continuous nerve block catheter subsequently allowed for nearly pain-free low impact passive and guided active mobilization by the performing physiotherapist for three consecutive weeks. This case and a short topical review on the use of SSN block in painful shoulder conditions highlight the possibility of a USG continuous nerve block of the SSN as sufficient pain management in the immediate post-operative period following capsular release of the shoulder. Findings in other painful shoulder conditions and suggestions for future studies are discussed in the text. © 2011 The Authors. Journal compilation © 2011 The Acta Anaesthesiologica Scandinavica Foundation.
Tazawa, Toshiharu; Kamiya, Yoshinori; Takamori, Mina; Ogawa, Ken-Ichi; Goto, Takahisa
Ventral disc protrusions have been neglected because they are asymptomatic. Lumbar sympathetic nerve block (LSNB) is one of the clinical choices for refractory low back pain treatment. Leakage of the contrast medium may occur and lead to complications, especially when using a neurolytic agent. In this study, we retrospectively reviewed the magnetic resonance images (MRIs) of 52 consecutive patients with refractory low back pain due to lumbar spinal canal stenosis who underwent LSNB, and graded ventral disc protrusion at the L1/2 to L5/S1 vertebral discs on a three-point scale (grade 0 = no protrusion, grade 1 = protrusion without migration, grade 2 = protrusion with migration). We also determined if there was leakage of contrast medium in LSNB. Ventral disc protrusion was observed in all patients, and 75 % (39/52) had grade 2 protrusion in the L1/2-L3/4 vertebral discs. Moreover, the incidence of contrast medium leakage was significantly higher at the vertebrae that had grade 2 protrusion than at those with less protrusion. We revealed a higher incidence of ventral disc protrusion of the lumbar vertebrae than previously reported, and that the incidence of leakage in LSNB increased when ventral disc protrusion was present. To avoid complications, attention should be paid to ventral disc protrusions before performing LSNB.
Holman, Shaina Devi; Gierbolini-Norat, Estela M.; Lukasik, Stacey L.; Campbell-Malone, Regina; Ding, Peng; German, Rebecca Z.
Summary Bupivacaine hydrochloride is frequently used in veterinary dental procedures to reduce the amount of general anesthesia needed and to reduce post-procedural pain. The aim of this study was to develop a novel method to test local anesthetic duration in mammals. Six infant pigs were placed under deep/surgical anesthesia with 3 % isoflurane and oxygen while 0.5 ml of 0.5 % bupivacaine hydrochloride was injected to block the two greater palatine and the nasopalatine nerves. They were then maintained under light anesthesia with 0.5–1.0 % isoflurane. Beginning 15-minutes after the injection, 7 sites in the oral cavity were stimulated using a pointed dental waxing instrument, including 3 sites on the hard palate. The response, or lack of response, to the stimulus was recorded on video and in written record. The bupivacaine hydrochloride injections lasted 1 to 3-hours before the animals responded to the sensory stimulation with a reflexive movement. This study provides evidence that bupivacaine used to anesthetize the hard palate has a relatively short and variable duration of action far below what is expected based on its pharmacokinetic properties. PMID:25185333
AlHindi, Maryam; Rashed, Bayan; AlOtaibi, Noura
Objectives: To report the failure rate of inferior alveolar nerve block (IANB) among dental students and interns, causes of failure, investigate awareness of different IANB techniques, and to report IANB-associated complications. Methods: A 3-page questionnaire containing 13 questions was distributed to a random sample of 350 third to fifth years students and interns at the College of Dentistry, King Saud University, Riyadh, Saudi Arabia on January 2011. It included demographic questions (age, gender, and academic level) and questions on IANB failure frequency and reasons, actions taken to overcome the failure, and awareness of different anesthetic techniques, supplementary techniques, and complications. Results: Of the 250 distributed questionnaires, 238 were returned (68% response rate). Most (85.7%) of surveyed sample had experienced IANB failure once or twice. The participants attributed the failures most commonly (66.45%) to anatomical variations. The most common alternative technique used was intraligamentary injection (57.1%), although 42.8% of the sample never attempted any alternatives. Large portion of the samples stated that they either lacked both knowledge of and training for other techniques (44.9%), or that they had knowledge of them but not enough training to perform them (45.8%). Conclusion: To decrease IANB failure rates for dental students and interns, knowledge of landmarks, anatomical variation and their training in alternatives to IANB, such as the Gow-Gates and Akinosi techniques, both theoretically and clinically in the dental curriculum should be enhanced. PMID:26739980
Jürgens, T P; Müller, P; Seedorf, H; Regelsberger, J; May, A
Occipital nerve block (ONB) has been used in several primary headache syndromes with good results. Information on its effects in facial pain is sparse. In this chart review, the efficacy of ONB using lidocaine and dexamethasone was evaluated in 20 patients with craniofacial pain syndromes comprising 8 patients with trigeminal neuralgia, 6 with trigeminal neuropathic pain, 5 with persistent idiopathic facial pain and 1 with occipital neuralgia. Response was defined as an at least 50% reduction of original pain. Mean response rate was 55% with greatest efficacy in trigeminal (75%) and occipital neuralgia (100%) and less efficacy in trigeminal neuropathic pain (50%) and persistent idiopathic facial pain (20%). The effects lasted for an average of 27 days with sustained benefits for 69, 77 and 107 days in three patients. Side effects were reported in 50%, albeit transient and mild in nature. ONBs are effective in trigeminal pain involving the second and third branch and seem to be most effective in craniofacial neuralgias. They should be considered in facial pain before more invasive approaches, such as thermocoagulation or vascular decompression, are performed, given that side effects are mild and the procedure is minimally invasive.
Case, Laura K; Gosavi, Radhika; Ramachandran, Vilayanur S
Mirror neurons allow us to covertly simulate the sensation and movement of others. If mirror neurons are sensory and motor neurons, why do we not actually feel this simulation- like "mirror-touch synesthetes"? Might afferent sensation normally inhibit mirror representations from reaching consciousness? We and others have reported heightened sensory referral to phantom limbs and temporarily anesthetized arms. These patients, however, had experienced illness or injury of the deafferented limb. In the current study we observe heightened sensory and motor referral to the face after unilateral nerve block for routine dental procedures. We also obtain double-blind, quantitative evidence of heightened sensory referral in healthy participants completing a mirror-touch confusion task after topical anesthetic cream is applied. We suggest that sensory and motor feedback exist in dynamic equilibrium with mirror representations; as feedback is reduced, the brain draws more upon visual information to determine- perhaps in a Bayesian manner- what to feel. Copyright © 2013 Elsevier Ltd. All rights reserved.
Adami, Chiara; Bergadano, Alessandra; Bruckmaier, Rupert M; Stoffel, Michael H; Doherr, Marcus G; Spadavecchia, Claudia
The aim of this study was to describe the sciatic-femoral nerve block (SFNB) in goats and to evaluate the peri-operative analgesia when the goats underwent stifle arthrotomy. The animals were randomly assigned to one of four treatment groups: groups 0.25, 0.5 and 0.75 received 0.25%, 0.5% and 0.75% of bupivacaine, respectively, while group C (control group) received 0.9% NaCl. In all groups, the volume administered was 0.2 mL/kg. Intra-operatively, the proportion of animals receiving rescue propofol was significantly lower in groups 0.5 and 0.75, compared to group C. Post-operatively, the visual analogue scale (VAS) and total pain score were significantly higher in group C than in the other groups. Group 0.75 had the highest percentage of animals showing motor blockade. SFNB performed with bupivacaine resulted in better intra- and post-operative analgesia than SFNB performed with saline. Compared to the other concentrations, 0.5% bupivacaine resulted in satisfactory analgesia with acceptable side effects.
Huang, Ren-Yeong; Chen, Ying-Jen; Fang, Wen-Hui; Mau, Lian-Ping; Shieh, Yi-Shing
Intraoral anesthesia is probably the most commonly used procedure in dentistry. Although inferior alveolar nerve block (IANB) anesthesia is one of the safest procedures to anesthetize the mandibular teeth, side effects of IANB anesthesia can still give rise to potential risks for patients. Fortunately, most observed alterations are transient and self-limited. The complications of IANB anesthesia are varied in nature and could be specifically categorized into systemic, localized, and distant complications. When the complications occur around the orofacial structures including the temporomandibular joint, middle ear, facial skin, and the eye, which are away from the oral cavity, it can be defined as distant complications. However, to our best knowledge, the concomitant occurrence of neurologic phenomena such as Horner syndrome combined with cutaneous complications in a patient receiving IANB anesthesia has never been discussed. In this exceptional case, the unusual Horner syndrome manifestations related to unilateral ptosis, miosis, and anisocoria were simultaneously developed with skin ischemia, paresthesia, and asymmetric flushing after the administration of IANB anesthesia. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
Hannan, Casey V; Albrecht, Matthew J; Petersen, Steve A; Srikumaran, Uma
The aim of this study was to compare liposomal bupivacaine and interscalene nerve block (ISNB) for analgesia after shoulder arthroplasty. We compared 37 patients who received liposomal bupivacaine vs 21 who received ISNB after shoulder arthroplasty by length of hospital stay (LOS), opioid consumption, and postoperative pain. Pain was the same in both groups for time intervals of 1 hour and 8 to 14 hours postoperatively. Compared with ISNB patients, liposomal bupivacaine patients reported less pain at 18 to 24 hours (P = .001) and 27 to 36 hours (P = .029) and had lower opioid consumption on postoperative days 2 (P = .001) and 3 (P = .002). Mean LOS for liposomal bupivacaine patients was 46 ± 20 hours vs 57 ± 14 hours for ISNB patients (P = .012). Sixteen of 37 liposomal bupivacaine patients vs 2 of 21 ISNB patients were discharged on the first postoperative day (P = .010). Liposomal bupivacaine was associated with less pain, less opioid consumption, and shorter hospital stays after shoulder arthroplasty compared with ISNB.
Hong, Myong-Joo; Kim, Yeon-Dong; Park, Jeong-Ki; Hong, Hyon-Joo
Pudendal neuralgia is characterized by chronic pain or discomfort in the area innervated by the pudendal nerve, with no obvious cause. A successful pudendal nerve block is crucial for the diagnosis of pudendal neuralgia. Blind or fluoroscopy-guided pudendal nerve blocks have been conventionally used for diagnosis and treatment; however, ultrasound-guided pudendal nerve blocks were also reported recently. With regard to the achievement of long-term effects, although pulsed radiofrequency performed under fluoroscopic guidance has been reported, that performed under ultrasound guidance is not well reported. This report describes two cases of pudendal neuralgia that were successfully managed using ultrasound-guided pulsed radiofrequency and presents a literature review of pudendal nerve block techniques. However, in the management of chronic neuropathic pain, physicians should keep in mind that the placebo effect related to invasive approaches must not be neglected.
Singla, Himanshi; Alexander, Mohan
Local anesthesia has been a boon for dentistry to allay the most common fear of pain among dental patients. Several techniques to achieve anesthesia for posterior maxillae have been advocated albeit with minor differences. We compared two techniques of posterior superior alveolar nerve block (PSANB), the one claimed to be "most accurate" to the one "most commonly used." This study was conducted to assess and compare the efficacy as well as complications of "the straight needle technique" to that of "the bent needle technique" for PSANB. We conducted a prospective, randomised, double blind study on 120 patients divided into two groups, using a 26-gauge, 38 mm long needle with 2 ml of 2 % lignocaine hydrochloride with 1:200,000 adrenaline solution. Objective symptoms were evaluated by a single investigator. Cold test using ice was used to evaluate the status of pulpal anesthesia. Data thus obtained was subjected to statistical analysis. Out of the 120 blocks, 19 blocks failed. Statistical analysis found straight needle technique to be more successful than the bent needle technique (p = 0.002). Both the techniques were equally effective for the first molar region on both right and left side (p = 0.66 on right side and p = 0.20 on left side). However, in the second and third molar region technique A was more effective than B (p = 0.01) on right side only. On Left side, both techniques were equally effective (p = 0.08). Sensitivity of the cold test was 82 % which is quite high but the specificity was 68 % which seems to be falling in the above average range only. Positive predictive value of 75 and negative predictive value of 76 was observed. We did not encounter any complications in this study. To the best of our knowledge, this is the first randomised controlled clinical study on PSANB techniques. This study suggests that the PSANB using the straight needle technique as advocated by Malamed  can be routinely and safely used to achieve anesthesia in
Lee, Ae-Ryung; Choi, Duck-Hwan; Choi, Soo-Joo; Hahm, Tae-Soo; Kim, Ga-Hyun; Moon, Young-Hwan
Purpose Total knee replacement is one of the most painful orthopedic procedures, and effective pain relief is essential for early mobility and discharge from hospital. The aim of this study was to evaluate whether addition of single-injection femoral nerve block to epidural analgesia would provide better postoperative pain control, compared to epidural analgesia alone, after total knee replacement. Materials and Methods Thirty-eight patients received a single-injection femoral nerve block with 0.25% levobupivacaine (30 mL) combined with epidural analgesia (femoral nerve block group) and 40 patients received epidural analgesia alone (control group). Pain intensity and volume of patient-controlled epidural analgesia medication and rescue analgesic requirements were measured in the first 48 hours after surgery at three time periods; 0-6 hours, 6-24 hours, and 24-48 hours. Also, side effects such as nausea, vomiting, and pruritus were evaluated. Results Median visual analog scale at rest and movement was significantly lower until 48 hours in the femoral nerve block group. Patient-controlled epidural analgesia volume was significantly lower throughout the study period, however, rescue analgesia requirements were significantly lower only up to 6 hours in the femoral nerve block group. The incidences of nausea and vomiting and rescue antiemetic requirement were significantly lower in the femoral nerve block group up to 6 hours. Conclusion The combination of femoral nerve block with epidural analgesia is an effective pain management regimen in patients undergoing unilateral total knee replacement. PMID:21155047
Joshi, R. P.; Mishra, A.; Hu, Q.; Schoenbach, K. H.; Pakhomov, A.
Simulation studies are presented that probe the possibility of using high-field (>100kV/cm) , short-duration (˜50ns) electrical pulses for nonthermal and reversible cessation of biological electrical signaling pathways. This would have obvious applications in neurophysiology, clinical research, neuromuscular stimulation therapies, and even nonlethal bioweapons development. The concept is based on the creation of a sufficiently high density of pores on the nerve membrane by an electric pulse. This modulates membrane conductance and presents an effective “electrical short” to an incident voltage wave traveling across a nerve. Net blocking of action potential propagation can then result. A continuum approach based on the Smoluchowski equation is used to treat electroporation. This is self-consistently coupled with a distributed circuit representation of the nerve dynamics. Our results indicate that poration at a single neural segment would be sufficient to produce an observable, yet reversible, effect.
Takasugi, Y.; Furuya, H.; Moriya, K.; Okamoto, Y.
The conventional inferior alveolar nerve block (conventional technique) has potential risks of neural and vascular injuries. We studied a method of inferior alveolar nerve block by injecting a local anesthetic solution into the pterygomandibular space anterior to the mandibular foramen (anterior technique) with the purpose of avoiding such complications. The insertion angle of the anterior technique and the estimation of anesthesia in the anterior technique were examined. The predicted insertion angle measured on computed tomographic images was 60.1 +/- 7.1 degrees from the median, with the syringe end lying on the contralateral mandibular first molar, and the insertion depth was approximately 10 mm. We applied the anterior technique to 100 patients for mandibular molar extraction and assessed the anesthetic effects. A success rate of 74% was obtained. This is similar to that reported for the conventional technique but without the accompanying risks for inferior alveolar neural and vascular complications. Images Figure 2 PMID:11432177
Drici, Milou-Daniel; Diochot, Sylvie; Terrenoire, Cécile; Romey, Georges; Lazdunski, Michel
Acetylcholine (ACh) is an important neuromodulator of cardiac function that is released upon stimulation of the vagus nerve. Despite numerous reports on activation of IKACh by acetylcholine in cardiomyocytes, it has yet to be demonstrated what role this channel plays in cardiac conduction. We studied the effect of tertiapin, a bee venom peptide blocking IKACh, to evaluate the role of IKACh in Langendorff preparations challenged with ACh.ACh (0.5 μM) reproducibly and reversibly induced complete atrioventricular (AV) blocks in retroperfused guinea-pig isolated hearts (n=12).Tertiapin (10 to 300 nM) dose-dependently and reversibly prevented the AV conduction decrements and the complete blocks in unpaced hearts (n=8, P<0.01).Tertiapin dose-dependently blunted the ACh-induced negative chronotropic response from an ACh-induced decrease in heart rate of 39±16% in control conditions to 3±3% after 300 nM tertiapin (P=0.01). These effects were not accompanied by any significant change in QT intervals.Tertiapin blocked IKACh with an IC50 of 30±4 nM with no significant effect on the major currents classically associated with cardiac repolarisation process (IKr, IKs, Ito1, Isus, IK1 or IKATP) or AV conduction (INa and ICa(L)).In summary, tertiapin prevents dose-dependently ACh-induced AV blocks in mammalian hearts by inhibiting IKACh. PMID:11015309
Lee, Jae Jun; Yoo, Yon-Sik; Hwang, Jung-Taek; Kim, Do-Young; Jeon, Seong-Jae; Hwang, Sung Mi; Jang, Ji Su
The purpose of this study was to evaluate the outcomes of arthroscopy-guided direct suprascapular nerve block performed after arthroscopic rotator cuff repair. In the present prospective, randomized, double-blinded clinical study, 30 patients were divided into two groups: 15 patients (group I) were treated with arthroscopy-guided suprascapular nerve block using 10 mL 0.5 % ropivacaine with 1:200,000 epinephrine, and 15 patients (group II) were treated with placebo using 10 mL 0.9 % saline after arthroscopic rotator cuff repair. Patient pain levels were measured using the visual analog scale (VAS) at 1, 3, 6, 12, 18, and 24 h post-operatively. Additionally, the number of boluses and total amount of fentanyl dispensed by patient-controlled analgesia administration during the 24-h post-operative period were evaluated. VAS scores did not differ significantly between groups I and II during the 24-h post-operative period, but mean fentanyl bolus consumption was significantly less in group I compared with group II (p = 0.015). Arthroscopy-guided suprascapular nerve block at the end of a rotator cuff repair was safe and less time-consuming than expected. Although this procedure did not significantly reduce the post-operative pain, the post-operative need for fentanyl boluses as analgesia was reduced significantly, and it would be beneficial if this procedure involved a sensory branch of axillary nerve block or was performed at the beginning of the arthroscopic procedure. Prospective, randomized, double-blinded clinical trial, Level I.
Jankovic, Zorica B; du Feu, Frances M; McConnell, Patricia
The transversus abdominis plane (TAP) block is a new technique for providing analgesia to the anterior abdominal wall. Most previous studies have used the lumbar triangle of Petit as a landmark for the block. In this cadaveric study, we determined the exact position and size of the lumbar triangle of Petit and identified the nerves affected by the TAP block. The position of the lumbar triangle of Petit was assessed unilaterally in 26 cadaveric specimens relative to reliably palpable surface landmarks. In addition, a series of dissections were performed to explore the course of the nerves blocked by the TAP. The mean distance from the midaxillary line along the iliac crest to the center of the base of the lumbar triangle of Petit at the level of the subcutaneous tissue and over the skin surface was 6.9 cm (range, 4.5-9.2 cm) and 9.3 cm (range, 4-15.1 cm), respectively. The center of the lumbar triangle of Petit was 1.4 cm above the iliac crest. The depth of the TAP at the lumbar triangle of Petit position was 0.5-4 cm and at the midaxillary line it was 0.5-2 cm. The average size of the lumbar triangle of Petit was 2.3 cm x 3.3 cm x 2.2 cm, with an average area of 3.63 +/- 1.93 cm2. The three cadaveric specimens we explored showed the nerves blocked by TAP passed lateral to the triangle. An incidental finding was that in 66% of specimens the lumbar triangle of Petit contained small branches of the subcostal artery. The lumbar triangles of Petit found in the specimens in this study were more posterior than the literature suggests. The position of the lumbar triangle of Petit varies largely and the size is relatively small. The relevant nerves to be blocked had not entered the TAP in the specimens in this study at the point of the lumbar triangle of Petit. At the midaxillary line, however, all the nerves were in the TAP.
Wang, Kun; Zhang, Hong-Xia
To illustrate the efficacy liposomal bupivacaine versus interscalene nerve block for pain management after total shoulder arthroplasty. A systematic search was performed in Medline, PubMed, Embase, ScienceDirect and the Cochrane Library. Data on patients prepared for total shoulder arthroplasty in studies that compared liposomal bupivacaine versus interscalene nerve block were retrieved. The endpoints were the visual analogue scale (VAS) and opioid consumption. Fixed/random effect model was used according to the heterogeneity tested by I(2) statistic. Software of Stata 11.0 was used for pooling the final outcomes. Four randomized controlled trials (RCTs) including 510 patients met the inclusion criteria. The present meta-analysis indicated that there were no significant differences between groups in terms of VAS score at 12 h, 24 h, and 48 h (p > 0.05). No significant differences were found regarding to opioid consumption at postoperative 12 h, 24 h and 48 h (p > 0.05). Compared with interscalene nerve block, liposomal bupivacaine had comparative effectiveness on reducing both pain scores and opioid consumption. Higher quality RCTs are required for further research. Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.
Chaubey, Deepika; Mahajan, Hari Krishan; Chauhan, Parshu Ram; Govind, Preeti S; Singh, Pushpinder; Dhanevar, Ravinder; Gupta, Abhinav
Local infiltration of knee joint in arthroplasty, provide postoperative analgesia and preserves motor power of quadriceps, which helps in early mobilisation, as compared to femoral nerve block which paralyses vastus medialis. To compare the quality of postoperative analgesia provided by femoral nerve block and local infiltration in unilateral Total Knee Arthroplasty (TKA). A prospective study was conducted on 60 patients (25-65 years) of ASA I and II, which were randomly(using random number table) divided into two groups - Group 1-femoral nerve block (FNB) and Group 2-Local Infiltration Analgesia (LIA). Patients with chronic pain and on opioids were excluded. Numeric rating scale (primary objective), sedation score, nausea vomiting score and motor power were analysed. The results were analysed by parametric and nonparametric tests using SPSS software version 22. p<0.05 was considered significant. Pain relief was better in FNB Group (p-value <0.001) with less fentanyl demand (p-value <0.001), low sedation score (0.013, 0.179, 0.018, 0.129, 0.287, 0.432) but associated with low muscle power grading (<0.001). FNB has better pain relief than LIA Group but range of motion was reduced in FNB Group grossly, effect on mobilisation remained comparable in both group.
Sondekoppam, Rakesh V; Tsui, Ban C H
The onset of neurologic complications after regional anesthesia is a complex process and may result from an interaction of host, agent, and environmental risk factors. The purpose of this systematic review was examine the qualitative evidence relating to various risk factors implicated in neurologic dysfunction after peripheral nerve block (PNB). The MEDLINE, OVID, and EMBASE databases were primary sources for literature. Cochrane, LILACS, DARE, IndMed, ERIC, NHS, and HTA via Centre for Reviews and Dissemination (CRD; York University) databases were searched for additional unique results. Randomized controlled studies, case-control studies, cohort studies, retrospective reviews, and case reports/case series reporting neurologic outcomes after PNB were included. Relevant, good-quality systematic reviews were also eligible. Human and animal studies evaluating factors important for neurologic outcomes were assessed separately. Information on study design, outcomes, and quality was extracted and reviewed independently by the 2 review authors. An overall rating of the quality of evidence was assigned using GRADE (Grading of Recommendations Assessment, Development and Evaluation) criteria. Relevant full-text articles were separated based on type (prospective, retrospective, and nonhuman studies). Strengths of association were defined as high, moderate, inconclusive, or inadequate based on study quality and direction of association. The evidence from 77 human studies was reviewed to assess various host, agent, and environmental factors that have been implicated as possible risks. Most of the available evidence regarding the injurious effects of the 3 cardinal agents of mechanical insult, pressure, and neurotoxicity was extracted from animal studies (42 studies). Among the risk factors investigated in humans, block type had a strong association with neurologic outcome. Intraneural injection, which seems to occur commonly with PNBs, showed an inconsistent direction of
Corrêa, Cléber Gimenez; Machado, Maria Aparecida de Andrade Moreira; Ranzini, Edith; Tori, Romero; Nunes, Fátima de Lourdes Santos
This study shows the development and validation of a dental anesthesia-training simulator, specifically for the inferior alveolar nerve block (IANB). The system developed provides the tactile sensation of inserting a real needle in a human patient, using Virtual Reality (VR) techniques and a haptic device that can provide a perceived force feedback in the needle insertion task during the anesthesia procedure. To simulate a realistic anesthesia procedure, a Carpule syringe was coupled to a haptic device. The Volere method was used to elicit requirements from users in the Dentistry area; Repeated Measures Two-Way ANOVA (Analysis of Variance), Tukey post-hoc test and averages for the results' analysis. A questionnaire-based subjective evaluation method was applied to collect information about the simulator, and 26 people participated in the experiments (12 beginners, 12 at intermediate level, and 2 experts). The questionnaire included profile, preferences (number of viewpoints, texture of the objects, and haptic device handler), as well as visual (appearance, scale, and position of objects) and haptic aspects (motion space, tactile sensation, and motion reproduction). The visual aspect was considered appropriate and the haptic feedback must be improved, which the users can do by calibrating the virtual tissues' resistance. The evaluation of visual aspects was influenced by the participants' experience, according to ANOVA test (F=15.6, p=0.0002, with p<0.01). The user preferences were the simulator with two viewpoints, objects with texture based on images and the device with a syringe coupled to it. The simulation was considered thoroughly satisfactory for the anesthesia training, considering the needle insertion task, which includes the correct insertion point and depth, as well as the perception of tissues resistances during the insertion.
CORRÊA, Cléber Gimenez; MACHADO, Maria Aparecida de Andrade Moreira; RANZINI, Edith; TORI, Romero; NUNES, Fátima de Lourdes Santos
Abstract Objectives This study shows the development and validation of a dental anesthesia-training simulator, specifically for the inferior alveolar nerve block (IANB). The system developed provides the tactile sensation of inserting a real needle in a human patient, using Virtual Reality (VR) techniques and a haptic device that can provide a perceived force feedback in the needle insertion task during the anesthesia procedure. Material and Methods To simulate a realistic anesthesia procedure, a Carpule syringe was coupled to a haptic device. The Volere method was used to elicit requirements from users in the Dentistry area; Repeated Measures Two-Way ANOVA (Analysis of Variance), Tukey post-hoc test and averages for the results’ analysis. A questionnaire-based subjective evaluation method was applied to collect information about the simulator, and 26 people participated in the experiments (12 beginners, 12 at intermediate level, and 2 experts). The questionnaire included profile, preferences (number of viewpoints, texture of the objects, and haptic device handler), as well as visual (appearance, scale, and position of objects) and haptic aspects (motion space, tactile sensation, and motion reproduction). Results The visual aspect was considered appropriate and the haptic feedback must be improved, which the users can do by calibrating the virtual tissues’ resistance. The evaluation of visual aspects was influenced by the participants’ experience, according to ANOVA test (F=15.6, p=0.0002, with p<0.01). The user preferences were the simulator with two viewpoints, objects with texture based on images and the device with a syringe coupled to it. Conclusion The simulation was considered thoroughly satisfactory for the anesthesia training, considering the needle insertion task, which includes the correct insertion point and depth, as well as the perception of tissues resistances during the insertion. PMID:28877273
Yeh, Yu-Cheng; Luo, Chi-An; Joey-Tan, Kit-Yang
Background The technique used to administer a selective nerve root block (SNRB) varies depending on individual expertise. Both the anteroposterior (AP) subpedicular approach and oblique Scotty dog subpedicular approach are widely practiced. However, the literature does not provide a clear consensus regarding which approach is more suitable. Hence, we decided to analyse the procedural parameters and clinical outcomes following SNRBs using these two approaches. Methods Patients diagnosed with a single lumbar herniated intervertebral disc (HIVD) refractory to conservative management but not willing for immediate surgery were selected for a prospective nonrandomized comparative study. An SNRB was administered as a therapeutic alternative using the AP subpedicular approach in one group (n = 25; mean age, 45 ± 5.4 years) and the oblique Scotty dog subpedicular approach in the other group (n = 22; mean age, 43.8 ± 4.7 years). Results were compared in terms of the duration of the procedure, the number of C-arm exposures, accuracy, pain relief, functional outcome and the duration of relief. Results Our results suggest that the oblique Scotty dog subpedicular approach took a significantly longer duration (p = 0.02) and a greater number of C-arm exposures (p = 0.001). But, its accuracy of needle placement was 95.5% compared to only 72% using the AP subpedicular approach (p = 0.03). There was no significant difference in terms of clinical outcomes between these approaches. Conclusions The AP subpedicular approach was simple and facile, but the oblique Scotty dog subpedicular approach was more accurate. However, a brief window period of pain relief was achieved irrespective of the approaching technique used. PMID:28261430
Melton, M Stephen; Browndyke, Jeffrey N; Harshbarger, Todd B; Madden, David J; Nielsen, Karen C; Klein, Stephen M
Limited information exists on the effects of temporary functional deafferentation (TFD) on brain activity after peripheral nerve block (PNB) in healthy humans. Increasingly, resting-state functional connectivity (RSFC) is being used to study brain activity and organization. The purpose of this study was to test the hypothesis that TFD through PNB will influence changes in RSFC plasticity in central sensorimotor functional brain networks in healthy human participants. The authors achieved TFD using a supraclavicular PNB model with 10 healthy human participants undergoing functional connectivity magnetic resonance imaging before PNB, during active PNB, and during PNB recovery. RSFC differences among study conditions were determined by multiple-comparison-corrected (false discovery rate-corrected P value less than 0.05) random-effects, between-condition, and seed-to-voxel analyses using the left and right manual motor regions. The results of this pilot study demonstrated disruption of interhemispheric left-to-right manual motor region RSFC (e.g., mean Fisher-transformed z [effect size] at pre-PNB 1.05 vs. 0.55 during PNB) but preservation of intrahemispheric RSFC of these regions during PNB. Additionally, there was increased RSFC between the left motor region of interest (PNB-affected area) and bilateral higher order visual cortex regions after clinical PNB resolution (e.g., Fisher z between left motor region of interest and right and left lingual gyrus regions during PNB, -0.1 and -0.6 vs. 0.22 and 0.18 after PNB resolution, respectively). This pilot study provides evidence that PNB has features consistent with other models of deafferentation, making it a potentially useful approach to investigate brain plasticity. The findings provide insight into RSFC of sensorimotor functional brain networks during PNB and PNB recovery and support modulation of the sensory-motor integration feedback loop as a mechanism for explaining the behavioral correlates of peripherally
González Sotelo, V; Maculé, F; Minguell, J; Bergé, R; Franco, C; Sala-Blanch, X
Total knee arthroplasty (TKA) is an operation with moderate to severe postoperative pain. The Fast-Track models employ local infiltration techniques with anaesthetics at high volumes (100-150ml). We proposed a genicular nerve block with low volume of local anaesthetic. The aim of our study is to evaluate the periarticular distribution of these blocks in a fresh cadaver model and to describe the technique in a preliminary group of patients submitted to TKA. In the anatomical phase, 4 genicular nerves (superior medial, superior lateral, inferior medial and inferior lateral) were blocked with 4ml of local anaesthetic with iodinated contrast and methylene blue in each (16ml in total). It was performed on a fresh cadaver and the distribution of the injected medium was evaluated by means of a CT-scan and coronal anatomical sections on both knees. The clinical phase included 12 patients scheduled for TKA. Ultrasound-guided block of the 4 genicular nerves was performed preoperatively and their clinical efficacy evaluated by assessing pain after the reversal of the spinal block and at 12h after the block. Pain was measured using the numerical scale and the need for rescue analgesia was evaluated. A wide periarticular distribution of contrast was observed by CT-scan, which was later evaluated in the coronal sections. The distribution followed the joint capsule without entering the joint, both in the femur and in the tibia. The pain after the reversal of the subarachnoid block was 2±1, requiring rescue analgesia in 42% of the patients. At 12h, the pain according to the numerical scale was 4±1, 33% required rescue analgesia. The administration of 4ml of local anaesthetic at the level of the 4 genicular nerves of the knee produces a wide periarticular distribution. Our preliminary data in a series of 12 patients undergoing TKA seems to be clinically effective. Nevertheless, extensive case series and comparative studies with local infiltration techniques with anaesthetics are
Kollmann-Camaiora, A; Brogly, N; Alsina, E; Gilsanz, F
Although ultrasound is a basic competence for anaesthesia residents (AR) there is few data available on the learning process. This prospective observational study aims to assess the learning process of ultrasound-guided continuous femoral nerve block and to determine the number of procedures that a resident would need to perform in order to reach proficiency using the cumulative sum (CUSUM) method. We recruited 19 AR without previous experience. Learning curves were constructed using the CUSUM method for ultrasound-guided continuous femoral nerve block considering 2 success criteria: a decrease of pain score>2 in a [0-10] scale after 15minutes, and time required to perform it. We analyse data from 17 AR for a total of 237 ultrasound-guided continuous femoral nerve blocks. 8/17 AR became proficient for pain relief, however all the AR who did more than 12 blocks (8/8) became proficient. As for time of performance 5/17 of AR achieved the objective of 12minutes, however all the AR who did more than 20 blocks (4/4) achieved it. The number of procedures needed to achieve proficiency seems to be 12, however it takes more procedures to reduce performance time. The CUSUM methodology could be useful in training programs to allow early interventions in case of repeated failures, and develop competence-based curriculum. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.
Fedriani de Matos, J J; Atienza Carrasco, F J; Díaz Crespo, J; Moreno Martín, A; Tatsidis Tatsidis, P; Torres Morera, L M
Total knee arthroplasty is associated with severe postoperative pain. The aim of this study was to compare continuous ultrasound-guided femoral nerve block with continuous epidural analgesia, both with low concentrations of local anaesthetic after total knee arthroplasty. A prospective, randomised, unblinded study of 60 patients undergoing total knee replacement, randomised into two groups. A total of 30 patients received continuous epidural block, while the other 30 received continuous ultrasound-guided femoral nerve block, as well as using 0.125% levobupivacaine infusion in both groups. Differences in pain control, undesirable effects, and complications between the two techniques were assessed, as well as the need for opioid rescue and the level of satisfaction with the treatment received during the first 48hours after surgery. No differences were found in demographic and surgical variables. The quality of analgesia was similar in both groups, although in the first six hours after surgery, patients in the epidural group had less pain both at rest and with movement (P=.007 and P=.011). This difference was not observed at 24hours (P=.084 and P=.942). Pain control at rest in the femoral block group was better at 48hours after surgery than in the epidural group (P=.009). The mean consumption of morphine and level of satisfaction were similar. Epidural analgesia showed the highest rate of side effects (P=.003). Continuous ultrasound-guided femoral nerve block provides analgesia and morphine consumption similar to epidural analgesia, with the same level of satisfaction, but with a lower rate of side effects after total knee arthroplasty. Copyright © 2016 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.
Lee, Doo H; Iyengar, Smriti; Lodge, David
L5 and L6 spinal nerve ligation (SNL) in rats leads to behavioral signs of neuropathic pain including mechanical allodynia. The purposes of this study were to investigate the role of the intact L4 spinal nerve in the development of mechanical allodynia following L5 and L6 SNL and, as a result, to develop a modified model of neuropathic pain. As a first set of experiments, in addition to tight ligation of the left L5 and L6 spinal nerves, the intact L4 spinal nerve was manipulated either (1) by gentle repeated stretching of the L4 spinal nerve immediately after L5 and L6 SNL or (2) by intermittent mechanical stimulation to the ipsilateral paw during the first week after SNL. Tactile sensitivity was measured by determining the foot withdrawal threshold before and after SNL. Mild irritation of L4 spinal nerve and application of mechanical stimuli to the ipsilateral paw significantly increased the development of mechanical allodynia after SNL. In a second set of experiments, SNL was produced by tightly ligating only the left L5 spinal nerve with or without a loop of 5-0 chromic gut placed loosely around the L4 spinal nerve. This additional L4 loop significantly increased long-lasting tactile sensitivity compared to L5 SNL alone. These results suggest that afferent activity of the intact L4 spinal nerve aids in the development of mechanical allodynia in the SNL model of neuropathic pain. The addition of a chromic gut loop around the intact L4 spinal nerve can augment the development of mechanical allodynia following SNL of L5. We propose this latter as a useful and practical animal model of neuropathic pain.
Luyet, Cédric; Constantinescu, Mihai; Waltenspül, Manuel; Luginbühl, Martin; Vögelin, Esther
Sonographic guidance for peripheral nerve anesthesia has proven increasingly successful in clinical practice; however, fears that a change to sonographically guided regional anesthesia may impair the block quality and operating room work flow persist in certain units. In this retrospective cohort study, block quality and patient satisfaction during the transition period from nerve stimulator to sonographic guidance for axillary brachial plexus anesthesia in a tertiary referral center were investigated. Anesthesia records of all patients who had elective surgery of the wrist or hand during the transition time (September 1, 2006-August 25, 2007) were reviewed for block success, placement time, anesthesiologist training level, local anesthetic volume, and requirement of additional analgesics. Postoperative records were reviewed, and patient satisfaction was assessed by telephone interviews in matched subgroups. Of 415 blocks, 341 were sonographically guided, and 74 were nerve stimulator guided. Sonographically guided blocks were mostly performed by novices, whereas nerve stimulator-guided blocks were performed by advanced users (72.3% versus 14%; P < .001). Block performance times and success rates were similar in both groups. In sonographically guided blocks, significantly less local anesthetics were applied compared to nerve stimulator-guided blocks (mean ± SD, 36.1 ± 7.1 versus 43.9 ± 6.1 mL; P< .001), and less opioids were required (fentanyl, 66.1 ± 30 versus 90 ± 62 μg; P< .001). Interviewed patients reported significantly less procedure-related discomfort, pain, and prolonged procedure time when block placement was sonographically guided (2% versus 20%; P = .002). Transition from nerve stimulator to sonographic guidance for axillary brachial plexus blocks did not change block performance times or success rates. Patient satisfaction was improved even during the early institutional transition period.
Fabregat López, J; Porta Vila, G; Martin-Flores, M
We report two cases in which moderate and intense rocuronium-induced neuromuscular block was reversed intraoperatively with low sugammadex doses in order to facilitate electromyographic evaluation of facial nerve function during surgery of the parotid gland and the middle ear. Acceleromyography was used to assess reversal of neuromuscular block before starting electromyography monitoring. Rocuronium-induced neuromuscular block was reversed with sugammadex 0.22mgkg(-1) when the TOF ratio was 0.14 in the first patient, and with sugammadex 2mgkg(-1) during intense block (PTC 0) in the second patient. In each case, appropriate neuromuscular function (TOF ratio≥0.9) was established soon after sugammadex administration, and electromyographic evaluation of facial nerve was successfully conducted. The use of rocuronium and sugammadex, coupled with objective neuromuscular monitoring with acceleromyography, assured complete restoration of neuromuscular function and created the optimal conditions for the surgical team. Copyright © 2012 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.
Yung, Elliot; Yarmush, Joel M; Weinberg, Jonathan; SchianodiCola, Joseph J; Ray, Sidhartha D
This study investigates the relative potencies and ED(50) of the local anesthetics lidocaine and chloroprocaine in a sciatic block in Sprague-Dawley rats. The study involved 80 rats (chloroprocaine n = 40, lidocaine n = 40). Each rat was injected close to the sciatic nerve with 0.1 ml of the concentration of local anesthetic being tested. Using the up-and-down allocation technique, the next concentration was determined by the response of the previous subject to a higher or lower concentration. A successful block was assessed by pinching the fifth metatarsal. Absent vocalization and a very weak withdrawal response were defined as the onset of block. Using the up-and-down methodology, the estimates of ED(50) for chloroprocaine was 0.1 ml of 1.2% (with 95% CI of 1.1-1.6), and that for lidocaine was 0.1 ml of 0.65% (with 95% CI of 0.65-0.88), giving a lidocaine/chloroprocaine potency ratio of 1.85 (with 95% CI of 1.66-2.61). Using the results of this study, the effects of the two drugs can be compared using the commercially available concentrations of chloroprocaine and lidocaine in a peripheral nerve block. Copyright 2009 S. Karger AG, Basel.
Rowan, E. G.; Harvey, A. L.
1. beta-Bungarotoxin and other snake toxins with phospholipase activity augment acetylcholine release evoked from mouse motor nerve terminals before they produce blockade. This action of the toxins is independent of their phospholipase A2 activity, but the underlying mechanism for the facilitation of release is unclear. To determine whether the toxins affect ionic currents at motor nerve terminals, extracellular recordings were made from perineural sheaths of motor nerves innervating mouse triangularis sterni muscles. 2. Perineural waveforms had a characteristic shape, with two major negative deflections, the first being associated with nodal Na+ currents and the second with terminal K+ currents. Block of the K+ currents revealed a Ca2+-dependent component. 3. During the facilitatory phase of its action, beta-bungarotoxin (150 nM) reduced the second negative component of the perineural waveform by 30-50%. 4. The reduction could be a consequence of a decreased K+ ion contribution or of an increase in the current carried by Ca2+. As beta-bungarotoxin had similar effects in solutions which contained no added Ca2+, it is unlikely to be acting on the Ca2+ current. Also, it is unlikely to be blocking the Ca2+-activated K+ current, which is suppressed in zero Ca2+ conditions. 5. Other prejunctionally active snake toxins (taipoxin, notexin and crotoxin) had similar effects to those of beta-bungarotoxin, but a similar basic phospholipase of low toxicity from cobra venom had no effect. 6. Thus, beta-bungarotoxin and related toxins block a fraction of the K+ current in the motor nerve terminals of mouse preparations.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3263160
Estimation and pharmacodynamic consequences of the minimum effective anesthetic volumes for median and ulnar nerve blocks: a randomized, double-blind, controlled comparison between ultrasound and nerve stimulation guidance.
Ponrouch, Matthieu; Bouic, Nicolas; Bringuier, Sophie; Biboulet, Philippe; Choquet, Olivier; Kassim, Michèle; Bernard, Nathalie; Capdevila, Xavier
Nerve stimulation and ultrasound guidance are the most popular techniques for peripheral nerve blocks. However, the minimum effective anesthetic volume (MEAV) in selected nerves for both techniques and the consequences of decreasing the local anesthetic volume on the pharmacodynamic characteristics of nerve block remain unstudied. We designed a randomized, double-blind controlled comparison between neurostimulation and ultrasound guidance to estimate the MEAV of 1.5% mepivacaine and pharmacodynamics in median and ulnar nerve blocks. Patients scheduled for carpal tunnel release were randomized to ultrasound guidance (UG) or neurostimulation (NS) groups. A step-up/step-down study model (Dixon method) was used to determine the MEAV with nonprobability sequential dosing based on the outcome of the previous patient. The starting dose of 1.5% mepivacaine was 13 and 11 mL for median and ulnar nerves at the humeral canal. Block success/failure resulted in a decrease/increase of 2 mL. A blinded physician assessed sensory blockade at 2-minute intervals for 20 minutes. Block onset time and duration were noted. The MEAV50 (SD) of the median nerve was lower in the UG group 2 (0.1) mL (95% confidence interval [CI] = [1, 96] to [2, 04]) than in the NS group 4 (3.8) mL (95% CI = [2, 4] to [5, 6]) (P = 0.017). There was no difference for the ulnar nerve between UG group 2 (0.1) mL (95% CI = [1, 96] to [2, 04]) and NS group 2.4 (0.6) mL (95% CI = [2, 1] to [2, 7]). The duration of sensory blockade was significantly correlated to local anesthetic volume, but onset time was not modified. Ultrasound guidance selectively provided a 50% reduction in the MEAV of mepivacaine 1.5% for median nerve sensory blockade in comparison with neurostimulation. Decreasing the local anesthetic volume can decrease sensory block duration but not onset time.
Kwofie, M Kwesi; Shastri, Uma D; Gadsden, Jeff C; Sinha, Sanjay K; Abrams, Jonathan H; Xu, Daquan; Salviz, Emine A
Adductor canal block (ACB) has been suggested as an analgesic alternative to femoral nerve block (FNB) for procedures on the knee, but its effect on quadriceps motor function is unclear. We performed a randomized, blinded study to compare quadriceps strength following adductor canal versus FNB in volunteers. Our hypothesis was that quadriceps strength would be preserved following ACB, but not FNB. Secondary outcomes included relative preservation of hip adduction and degree of balance impairment. The ACB was performed in one leg and the FNB in the contralateral leg in 16 volunteers using a randomized block sequence. For all blocks, 15 mL of 3% chloroprocaine was injected under ultrasonographic guidance. Maximal voluntary isometric contraction of knee extension and hip adduction was measured at baseline and at 30 and 60 minutes after block. After 60-minute assessments were complete, the second block was placed. A test of balance (Berg Balance Scale) was performed 30 minutes after the first block only. Quadriceps strength and balance scores were similar to baseline following ACB. Following FNB, there was a significant reduction in quadriceps strength (95.1% ± 17.1% vs 11.1% ± 14.0%; P < 0.0001) and balance scores (56 ± 0 vs 37 ± 17.2; P = 0.02) compared with baseline. There was no difference in hip adductor strength (97.0% ± 10.8% vs 91.8% ± 9.6%; P = 0.17). Compared with FNB, ACB results in significant quadriceps motor sparing and significantly preserved balance.
Ustuner, Evren; Yılmaz, Ayse; Özgencil, Enver; Okten, Feyhan; Turhan, Sanem Cakar
Familiarity with the localization of the nerves in the neurovascular bundle that constitutes the axillary segment of the brachial plexus (BP) is important when applying ultrasound (US)-guided block anesthesia. Therefore in this study we aimed to delineate the anatomy of the median, radial, and ulnar nerves of the BP at the axilla with US and electrical stimulation. The study included 60 patients who were scheduled to undergo upper-arm surgery with axillary block anesthesia. Prior to anesthesia, ulnar, radial, and median nerves were localized with US using a 12-h quadrant identification system that placed the axillary artery (AA) in the middle. The nerves were then functionally tested using a neurostimulator. The radial nerve was mainly located in the 4-6 o'clock arc (posterior and posteromedial to AA) in 50 (83 %) of patients. Ulnar nerve was mainly at the 12-3 o'clock arc (anteromedial to AA) in 51 (85 %) of patients. Ulnar nerve showed a second peak at 9-10 o'clock quadrant (anterolateral to AA) in 11 % (7) of patients. Median nerve location was most common in the 12 and 9 o'clock arc (anterior and anterolateral to AA) in 53 (88 %) of the patients. Ultrasound is a useful tool for depicting BP anatomy in the axillary fossa prior to block anesthesia. Median, ulnar, and radial nerves form a highly consistent triangular pattern around the axillary artery that is easily recognizable with US.
Shipley, Kyle; Riew, K Daniel; Gilula, Louis A
Study Design Retrospective evaluation of consecutively performed fluoroscopically guided cervical nerve root blocks. Objective To describe the incidence of injectate central epidural flow with respect to needle tip position during fluoroscopically guided extraforaminal cervical nerve root blocks (ECNRBs). Methods Between February 19, 2003 and June 11, 2003, 132 consecutive fluoroscopically guided ECNRBs performed with contrast media in the final injected material (injectate) were reviewed on 95 patients with average of 1.3 injections per patient. Fluoroscopic spot images documenting the procedure were obtained as part of standard quality assurance. An independent observer not directly involved in the procedures retrospectively reviewed the images, and the data were placed into a database. Image review was performed to determine optimal needle tip positioning for injectate epidural flow. Results Central epidural injectate flow was obtained in only 28.9% of injections with the needle tip lateral to midline of the lateral mass (zone 2). 83.8% of injectate went into epidural space when the needle tip was medial to midline of the lateral mass (zone 3). 100% of injectate flowed epidurally when the needle tip was medial to or at the medial cortex of the lateral mass (zone 4). There was no statistically significant difference with regards to central epidural flow and the needle tip position on lateral view. Conclusion To ensure central epidural flow with ECNRBs one must be prepared to pass the needle tip medial to midplane of the lateral mass or to medial cortex of the lateral mass. Approximately 16% of ECNRBs with needle tip medial to midline of the lateral mass did not flow into epidural space. One cannot claim a nerve block is an epidural block unless epidural flow of injectate is observed.
Snyder, Christopher J; Snyder, Lindsey B C
To evaluate the effects of a routinely used infraorbital nerve block, performed for dental procedures, on the anesthetic requirement for isoflurane in dogs. Prospective controlled study. 8 healthy adult Beagles. Dogs were anesthetized with isoflurane, and the minimum alveolar concentration (MAC) of isoflurane was established. A modification of a well-established method of stimulating the dental pulp, dental dolorimetry, was used to deliver a noxious stimulus (electrical stimulation) for isoflurane MAC determination. Once the isoflurane MAC was established, an infraorbital nerve block was performed with mepivacaine. The isoflurane MAC was then determined with the addition of the nerve block. Measurements of heart rate and mean arterial blood pressure were obtained at specified time points (baseline and prevention and elicitation of purposeful movement) during the determination of MAC and in response to the noxious stimulus. The mean ± SD isoflurane MAC without an infraorbital nerve block was 1.12 ± 0.13%. Isoflurane MAC with the regional mepivacaine anesthesia was 0.86 ± 0.11%. A significant reduction in isoflurane MAC (23%) was seen after the infraorbital nerve block, compared with results before the nerve block. With the exception of baseline measurements, no significant differences were found between treatments (isoflurane alone vs isoflurane with regional mepivacaine anesthesia) in heart rate or mean arterial blood pressure before or after the noxious stimulus. The significant reduction in MAC of isoflurane supported the practice of the addition of regional anesthesia for painful dental procedures to reduce the dose-dependent cardiorespiratory effects of general anesthesia.
The vagus nerves branch off the brain on either side of the head and travel down the neck, along the ... the body, and affect swallowing and speech. The vagus nerves also connect to parts of the brain involved ...
Montserrat-Bosch, Marta; Figueiredo, Rui; Nogueira-Magalhães, Pedro; Arnabat-Dominguez, Josep; Valmaseda-Castellón, Eduard; Gay-Escoda, Cosme
To compare the efficacy and complication rates of two different techniques for inferior alveolar nerve blocks (IANB). A randomized, triple-blind clinical trial comprising 109 patients who required lower third molar removal was performed. In the control group, all patients received an IANB using the conventional Halsted technique, whereas in the experimental group, a modified technique using a more inferior injection point was performed. A total of 100 patients were randomized. The modified technique group showed a significantly higher onset time in the lower lip and chin area, and was frequently associated to a lingual electric discharge sensation. Three failures were recorded, 2 of them in the experimental group. No relevant local or systemic complications were registered. Both IANB techniques used in this trial are suitable for lower third molar removal. However, performing an inferior alveolar nerve block in a more inferior position (modified technique) extends the onset time, does not seem to reduce the risk of intravascular injections and might increase the risk of lingual nerve injuries.
Braga, M. F.; Anderson, A. J.; Harvey, A. L.; Rowan, E. G.
1. In mouse triangularis sterni nerve-muscle preparations, reduced extracellular Na+ concentrations and low concentrations of the Na+ channel blocking toxins tetrodotoxin (TTX, 18-36 nM) and mu-conotoxin GIIIB (0.4-2.0 microM) selectively decreased the amplitude of the component of perineural waveforms associated with nerve terminal K+ currents, without affecting the main Na+ spike. 2. Intracellular recording of endplate potentials (e.p.ps) and miniature endplate potentials (m.e.p.ps) from triangularis sterni preparations revealed that TTX and mu-conotoxin GIIIB depressed the evoked quantal release of acetylcholine without significant effects on m.e.p.p. amplitude, frequency or time constant of decay. 3. The apparent block of K+ current by low concentrations of TTX and mu-conotoxin is probably not a direct effect on K+ channels but results from a decrease in the passive depolarization of nerve terminals following blockade of a small proportion of axonal Na+ channels. PMID:1324070
Nader, Antoun; Kendall, Mark C; De Oliveria, Gildasio S; Chen, Jeffry Q; Vanderby, Brooke; Rosenow, Joshua M; Bendok, Bernard R
Patients presenting with facial pain often have ineffective pain relief with medical therapy. Cases refractory to medical management are frequently treated with surgical or minimally invasive procedures with variable success rates. We report on the use of ultrasound-guided trigeminal nerve block via the pterygopalatine fossa in patients following refractory medical and surgical treatment. To present the immediate and long-term efficacy of ultrasound-guided injections of local anesthetic and steroids in the pterygopalatine fossa in patients with unilateral facial pain that failed pharmacological and surgical interventions. Academic pain management center. Prospective case series. Fifteen patients were treated with ultrasound-guided trigeminal nerve block with local anesthetic and steroids placed into the pterygopalatine fossa. All patients achieved complete sensory analgesia to pin prick in the distribution of the V2 branch of the trigeminal nerve and 80% (12 out of 15) achieved complete sensory analgesia in V1, V2, V3 distribution within 15 minutes of the injection. All patients reported pain relief within 5 minutes of the injection. The majority of patients maintained pain relief throughout the 15 month study period. No patients experienced symptoms of local anesthetic toxicity or onset of new neurological sequelae. Prospective case series. We conclude that the use of ultrasound guidance for injectate delivery in the pterygopalatine fossa is a simple, free of radiation or magnetization, safe, and effective percutaneous procedure that provides sustained pain relief in trigeminal neuralgia or atypical facial pain patients who have failed previous medical interventions.
Jaber, A; Whitworth, J M; Corbett, I P; Al-Baqshi, B; Jauhar, S; Meechan, J G
The purpose of this trial was to assess the effect of soft tissue massage on the efficacy of the mental and incisive nerve block (MINB). Thirty-eight volunteers received MINB of 2.2 mL of 2% lidocaine with 1 : 80,000 epinephrine on 2 occasions. At one visit the soft tissue overlying the injection site was massaged for 60 seconds (active treatment). At the other visit the crowns of the mandibular premolar teeth were massaged (control treatment). Order of treatments was randomized. An electronic pulp tester was used to measure pulpal anesthesia in the ipsilateral mandibular first molar, a premolar, and lateral incisor teeth up to 45 minutes following the injection. The efficacy of pulp anesthesia was determined by 2 methods: (a) by quantifying the number of episodes with no response to maximal electronic pulp stimulation after each treatment, and (b) by quantifying the number of volunteers with no response to maximal pulp stimulation (80 reading) on 2 or more consecutive tests, termed anesthetic success. Data were analyzed by McNemar, Mann-Whitney, and paired-samples t tests. Anesthetic success was 52.6% for active and 42.1% for control treatment for lateral incisors, 89.5 and 86.8% respectively for premolars, and 50.0 and 42.1% respectively for first molars (P = .344, 1.0, and .508 respectively). There were no significant differences in the number of episodes of negative response to maximum pulp tester stimulation between active and control massage. A total of 131 episodes were recorded after both active and control massage in lateral incisors (McNemar test, P = 1.0), 329 (active) versus 316 (control) episodes in the premolars (McNemar test, P = .344), and 119 (active) versus 109 (control) episodes respectively for first molars (McNemar test, P = .444). Speed of anesthetic onset and discomfort did not differ between treatments. We concluded that soft tissue massage after MINB does not influence anesthetic efficacy.
Richard, Brigitte M.; Newton, Paul; Ott, Laura R.; Haan, Dean; Brubaker, Abram N.; Cole, Phaedra I.; Ross, Paul E.; Rebelatto, Marlon C.; Nelson, Keith G.
A sustained-release DepoFoam injection formulation of bupivacaine (EXPAREL, 15 mg/mL) is currently being investigated for postsurgical analgesia via peripheral nerve block (PNB). Single-dose toxicology studies of EXPAREL (9, 18, and 30 mg/kg), bupivacaine solution (Bsol, 9 mg/kg), and saline injected around the brachial plexus nerve bundle were performed in rabbits and dogs. The endpoints included clinical pathology, pharmacokinetics, and histopathology evaluation on Day 3 and Day 15 (2/sex/group/period). EXPAREL resulted in a nearly 4-fold lower C max versus Bsol at the same dose. EXPAREL was well tolerated at doses up to 30 mg/kg. The only EXPAREL-related effect seen was minimal to mild granulomatous inflammation of adipose tissue around nerve roots (8 of 24 rabbits and 7 of 24 dogs) in the brachial plexus sites. The results indicate that EXPAREL was well tolerated in these models and did not produce nerve damage after PNB in rabbits and dogs. PMID:22363842
Oprych, Karen M; Whitby, Raymond L D; Mikhalovsky, Sergey V; Tomlins, Paul; Adu, Jimi
Peripheral nerve injury continues to be a major global health problem that can result in debilitating neurological deficits and neuropathic pain. Current state-of-the-art treatment involves reforming the damaged nerve pathway using a nerve autograft. Engineered nerve repair conduits can provide an alternative to the nerve autograft avoiding the inevitable tissue damage caused at the graft donor site. Commercially available nerve repair conduits are currently only considered suitable for repairing small nerve lesions; the design and performance of engineered conduits requires significant improvements to enable their use for repairing larger nerve defects. Carbon nanotubes (CNTs) are an emerging novel material for biomedical applications currently being developed for a range of therapeutic technologies including scaffolds for engineering and interfacing with neurological tissues. CNTs possess a unique set of physicochemical properties that could be useful within nerve repair conduits. This progress report aims to evaluate and consolidate the current literature pertinent to CNTs as a biomaterial for supporting peripheral nerve regeneration. The report is presented in the context of the state-of-the-art in nerve repair conduit design; outlining how CNTs may enhance the performance of next generation peripheral nerve repair conduits.
Comparative Study of the Effects of the Retrocrural Celiac Plexus Block Versus Splanchnic Nerve Block, C-arm Guided, for Upper Gastrointestinal Tract Tumors on Pain Relief and the Quality of Life at a Six-month Follow Up
Shwita, Amera H.; Okab, Mohammad I.
Background The celiac plexus and splanchnic nerves are targets for neurolytic blocks for pain relief from pain caused by upper gastrointestinal tumors. Therefore, we investigated the analgesic effect of a celiac plexus block versus a splanchnic nerve block and the effects of these blocks on the quality of life six months post-intervention for patients with upper GIT tumors. Methods Seventy-nine patients with inoperable upper GIT tumors and with severe uncontrolled visceral pain were randomized into two groups. These were Group I, for whom a celiac plexus block was used with a bilateral needle retrocrural technique, and Group II, for whom a splanchnic nerve block with a bilateral needle technique was used. The visual analogue scale for pain (0 to 100), the quality of life via the QLQ-C30 questionnaire, and survival rates were assessed. Results Pain scores were comparable in both groups in the first week after the block. Significantly more patients retained good analgesia with tramadol in the splanchnic group from 16 weeks onwards (P = 0.005, 0.001, 0.005, 0.001, 0.01). Social and cognitive scales improved significantly from the second week onwards in the splanchnic group. Survival of both groups was comparable. Conclusions The results of this study demonstrate that the efficacy of the splanchnic nerve block technique appears to be clinically comparable to a celiac block. All statistically significant differences are of little clinical value. PMID:25589943
Szperka, Christina L; Gelfand, Amy A; Hershey, Andrew D
To describe current patterns of use of nerve blocks and trigger point injections for treatment of pediatric headache. Peripheral nerve blocks are often used to treat headaches in adults and children, but the available studies and practice data from adult headache specialists have shown wide variability in diagnostic indications, sites injected, and medication(s) used. The purpose of this study was to describe current practice patterns in the use of nerve blocks and trigger point injections for pediatric headache disorders. A survey was created in REDCap, and sent via email to the 82 members of the Pediatric and Adolescent Section of the American Headache Society in June 2015. The survey queried about current practice and use of nerve blocks, as well as respondents' opinions regarding gaps in the evidence for use of nerve blocks in this patient population. Forty-one complete, five incomplete, and three duplicate responses were submitted (response rate complete 50%). About 78% of the respondents identified their primary specialty as Child Neurology, and 51% were certified in headache medicine. Twenty-six (63%) respondents perform nerve blocks themselves, and seven (17%) refer patients to another provider for nerve blocks. Chronic migraine with status migrainosus was the most common indication for nerve blocks (82%), though occipital neuralgia (79%), status migrainosus (73%), chronic migraine without flare (70%), post-traumatic headache (70%), and new daily persistent headache (67%) were also common indications. The most commonly selected clinically meaningful response for status migrainosus was ≥50% reduction in severity, while for chronic migraine this was a ≥50% decrease in frequency at 4 weeks. Respondents inject the following locations: 100% inject the greater occipital nerve, 69% lesser occipital nerve, 50% supraorbital, 46% trigger point injections, 42% auriculotemporal, and 34% supratrochlear. All respondents used local anesthetic, while 12 (46%) also use
Olea, E; Fondarella, A; Sánchez, C; Iriarte, I; Almeida, M V; Martínez de Salinas, A
Evaluation of pain and degree of satisfaction in patients undergoing ultrasound-assisted peripheral regional block for the treatment of idiopathic palmar hyperhidrosis with botulinum toxin. A descriptive, observational study of patients with palmar hyperhidrosis treated with botulinum toxin A, who underwent ultrasound-guided peripheral regional block of the median and ulnar nerves with 3 ml of mepivacaine 1% in each one. The radial nerve block was injected in the anatomical snuffbox. After establishing blocking, the dermatologist performed a mapping and injected around 100 IU of botulinum toxin across the whole palm. The pain experienced during the injection of botulinum toxin was evaluated by verbal numerical scale (from 0 to 10), along with the degree of satisfaction with the anesthetic technique, and the post-anesthetic complications. A total of 40 patients were enrolled in the study, 11 men and 29 women with no significant differences. The pain intensity assessed with verbal numerical scale was 1.03 (standard deviation of 1.37). No patients had a value greater than 5. The degree of patient satisfaction with the anesthetic technique was very good for 85% of the patients, and good for 7.5%. There were no complications related to type of anesthesia. The ultrasound-assisted peripheral regional block could be a simple, effective and safe technique for patients undergoing palmar injection of botulinum toxin. Pain intensity was very low, and it provided a very good level of satisfaction in most patients. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.
Ferrero-Manzanal, Francisco; Lax-Pérez, Raquel; López-Bernabé, Roberto; Betancourt-Bastidas, José Ramiro; Iñiguez de Onzoño-Pérez, Alvaro
Shoulder surgery is often performed with the patient in the so called "beach-chair position" with elevation of the upper part of the body. The anesthetic procedure can be general anesthesia and/or regional block, usually interscalenic brachial plexus block. We present a case of brachial plexus palsy with a possible mechanism of traction based on the electromyographic and clinical findings, although a possible contribution of nerve block cannot be excluded. We present a case of a 62 year-old female, that suffered from shoulder fracture-dislocation. Open reduction and internal fixation were performed in the so-called "beach-chair" position, under combined general-regional anesthesia. In the postoperative period complete motor brachial plexus palsy appeared, with neuropathic pain. Conservative treatment included analgesic drugs, neuromodulators, B-vitamin complex and physiotherapy. Spontaneous recovery appeared at 11 months. DISCUSION: in shoulder surgery, there may be complications related to both anesthetic technique and patient positioning/surgical maneuvers. Regional block often acts as a confusing factor when neurologic damage appears after surgery. Intraoperative maneuvers may cause eventual traction of the brachial plexus, and may be favored by the fixed position of the head using the accessory of the operating table in the beach-chair position. When postoperative brachial plexus palsy appears, nerve block is a confusing factor that tends to be attributed as the cause of palsy by the orthopedic surgeon. The beach chair position may predispose brachial plexus traction injury. The head and neck position should be regularly checked during long procedures, as intraoperative maneuvers may cause eventual traction of the brachial plexus. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Suazo Galdames, Iván Claudio; Cantín López, Mario Gonzalo; Zavando Matamala, Daniela Alejandra
One of the most commonly used mandibular anesthesia techniques is the Spix technique, which is very useful in clinical practice, but is risky when the patient is a bearer of blood dyscrasias. The aim of this study was to present an alternative to the Spix technique in order to achieve troncular anesthesia of the inferior alveolar nerve. To this purpose, an infiltrative technique was designed to anesthetize the inferior alveolar nerve via the retromolar triangle. This study included 40 patients with an average age of 23.65 years, 22 males and 18 females, who were previously evaluated with a vitalometer control, then subjected to the designed anesthetic technique. The effectiveness of the technique used to anesthetize the inferior alveolar nerve was evaluated by the results of tests using a vitalometer applied to a molar and a premolar on the anesthetized side after 5, 10 and 15 minutes. Moreover, the anesthesia was evaluated in mucosa innervated regions by the inferior alveolar, lingual and buccal nerves, and by having the patient relate the duration of the induced feeling of numbness. The technique proved to be effective in 72.5% of the cases, with a latency of 10 minutes and an average duration of the anesthetic effect for 141.125 minutes. Moreover, anesthesia was obtained in the mucosa innervated regions by the inferior alveolar nerve in 72.5% of the cases, by the buccal nerve in 27.5% and in the innervated areas by the lingual nerve in 55% of the cases. The proposed technique, even when it proved to be less effective than the Spix technique, can be seen as a lower risk alternative for patients carrying blood dyscrasias and being subjected to dental procedures in mandibular teeth.
Feigl, Georg Christoph; Anderhuber, Friedrich; Dorn, Christian; Pipam, Wolfgang; Rosmarin, Walter; Likar, Rudolph
This paper presents an evaluation of a modified lateral suprascapular nerve block with easy orientation, low risk of displacement of the needle, and with an assessment of 2 different volumes to propose an ideal volume for a successful block. Both shoulders of 34 cadavers were investigated. Insertion point of the needle was determined in the angle of the lateral end of the clavicle, acromion, and the spine of the scapula. The needle was directed toward the medial, dorsal, and caudad direction. Ten mL of diluted contrast agent for computerized tomography was injected in the 34 right sides (group A) and 5 mL in the 34 left sides (group B). Immediately after injection, all shoulders were investigated by computerized tomography scans and 3-dimensional reconstruction to document the constrast dissemination. Five sides of each group were injected with colored contrast and dissected after computerized tomography investigation. Group A showed a distribution to the entire supraspinous fossa in all cases and the contrast was pressed out of the suprascapular notch in 4 cases with a maximal extension into the axillary fossa in 3 cases. In group B, the supraspinous fossa was filled in 24 cases, with a maximal extension to the axillary fossa in 2 cases. In 9 cases, the contrast agent stayed in the lateral half of the supraspinous fossa. In 1 case we had a medial spread only which still surrounded the suprascapular notch, in another case a superficial spread with misplacement of the needle. Based on this cadaver study, the lateral modified approach appears to be a safe technique for a suprascapular nerve block, which might be preferred as a single shot technique. A 5 mL volume appears sufficient to fill the supraspinous fossa and to reach the suprascapular nerve, which branches in this anatomical compartment.
Helal, Safaa M.; Eskandr, Ashraf M.; Gaballah, Khaled M.; Gaarour, Ihab S.
Background and Aim: Perineural administration of dexmedetomidine, a α2-adrenoceptor agonist, prolongs the duration of analgesia. We hypothesized that adding dexmedetomidine to bupivacaine would prolong postoperative analgesia after below knee surgery. Materials and Methods: After ethical approval, 60 patients scheduled for below knee surgery under combined femoral-sciatic nerve block were randomly allocated into two groups to have their block performed using bupivacaine 0.5% alone (group B) or bupivacaine 0.5% combined with 100 μg bupivacaine-dexmedetomidine (group BD). Motor and sensory block onset times; durations of blockades and analgesia were recorded. Results: Sensory and motor block onset times were shorter by 20% in group BD than in group B (P < 0.01). Sensory and motor blockade durations were longer in group BD (+45% and +40%, respectively) than in group B (P < 0.01). Duration of analgesia was longer in group BD by 75% than in group B (P < 0.01). Systolic, diastolic arterial blood pressure levels, and heart rate were significantly less in group BD, six patients in group BD, and no patients in group B developed bradycardia (P < 0.05). Conclusion: The addition of dexmedetomidine 100 μg to bupivacaine 0.5% during ultrasound-guided combined femoral and sciatic block for below knee surgery was associated with a prolonged duration of analgesia. However, this may be associated with significant bradycardia requiring treatment. PMID:26955305
AIM To report the effects of greater occipital nerve (GON) blocks on refractory chronic migraine headache. METHODS Nine patients who were receiving the conventionally accepted preventive therapies underwent treatment with repeated GON block to control chronic migraine resistant to other treatments. GON blocking with lidocaine and normal saline mixture was administered by the same physician at hospital once a month (for three times in total). Patients were assessed before the injection and every month thereafter for pain frequency and severity, number of times analgesics were used and any appearant side effects during a 6 mo follow-up. RESULTS Eight of nine patients reported a marked decrease in frequency and severity of migraine attacks in comparison to their baseline symptoms; one reported no significant change (not more than 50%) from baseline and did not accept the second injection. GON block resulted in considerable reduction in pain frequency and severity and need to use analgesics up to three months after the injection in the present cases. The patients did not report any adverse effects. CONCLUSION Hereby we noticed a remarkable success with refractory chronic migraine patients. We believe that this intervention can result in rapid relief of pain with the effects lasting for perhaps several weeks or even months. Further controlled clinical trials are warranted to evaluate the effect of GON block in the treatment of refractory migraine cases. PMID:27803914
Lindemann, Matthew; Reader, Al; Nusstein, John; Drum, Melissa; Beck, Mike
The purpose of this prospective, randomized, double-blind, placebo-controlled study was to determine the effect of the administration of sublingual triazolam on the success of the inferior alveolar nerve (IAN) block in patients experiencing irreversible pulpitis. Fifty-eight emergency patients diagnosed with irreversible pulpitis of a mandibular posterior tooth randomly received, in a double-blind manner, an identical sublingual tablet of either 0.25 mg of triazolam or a placebo 30 minutes before administration of a conventional IAN block. Access was begun 15 minutes after completion of the IAN block, and all patients had profound lip numbness. Success was defined as no or mild pain (visual analog scale recordings) on access or initial instrumentation. The success rate for the IAN block was 43% with triazolam and 57% with the placebo, with no significant difference (P = .43) between the 2 groups. For mandibular posterior teeth, triazolam in a sublingual dose of 0.25 mg did not result in an increase in success of the IAN block in patients with irreversible pulpitis. Therefore, when using conscious sedation, profound local anesthesia is still required to eliminate the sensation of pain during endodontic treatment for patients with irreversible pulpitis.
Kim, Hyun Jung; Ahn, Hyeong Sik; Lee, Jae Young; Choi, Seong Soo; Cheong, Yu Seon; Kwon, Koo; Yoon, Syn Hae
Background Postherpetic neuralgia (PHN) is a common and painful complication of acute herpes zoster. In some cases, it is refractory to medical treatment. Preventing its occurrence is an important issue. We hypothesized that applying nerve blocks during the acute phase of herpes zoster could reduce PHN incidence by attenuating central sensitization and minimizing nerve damage and the anti-inflammatory effects of local anesthetics and steroids. Methods This systematic review and meta-analysis evaluates the efficacy of using nerve blocks to prevent PHN. We searched the MEDLINE, EMBASE, Cochrane Library, ClinicalTrials.gov and KoreaMed databases without language restrictions on April, 30 2014. We included all randomized controlled trials performed within 3 weeks after the onset of herpes zoster in order to compare nerve blocks vs active placebo and standard therapy. Results Nine trials were included in this systematic review and meta-analysis. Nerve blocks reduced the duration of herpes zoster-related pain and PHN incidence of at 3, 6, and 12 months after final intervention. Stellate ganglion block and single epidural injection did not achieve positive outcomes, but administering paravertebral blockage and continuous/repeated epidural blocks reduced PHN incidence at 3 months. None of the included trials reported clinically meaningful serious adverse events. Conclusions Applying nerve blocks during the acute phase of the herpes zoster shortens the duration of zoster-related pain, and somatic blocks (including paravertebral and repeated/continuous epidural blocks) are recommended to prevent PHN. In future studies, consensus-based PHN definitions, clinical cutoff points that define successful treatment outcomes and standardized outcome-assessment tools will be needed. PMID:28119767
Bell, Elizabeth A; Jones, Brian P; Olufolabi, Adeyemi J; Dexter, Franklin; Phillips-Bute, Barbara; Greengrass, Roy A; Penning, Donald H; Reynolds, James D
To examine if ilioinguinal-iliohypogastric nerve block could reduce the need for post-Cesarean delivery morphine analgesia and thus reduce the incidence of opioid related adverse-effects. A multi-level technique for performing the nerve block with bupivacaine was developed and then utilized in this two-part study. Part one was a retrospective assessment of Cesarean delivery patients with and without ilioinguinal-iliohypogastric blocks to determine if the technique reduced patient controlled analgesia morphine use and thus would warrant further study. The second phase was a randomized double-blind placebo-controlled trial to compare post-Cesarean morphine use and the appearance of opioid-related side effects between the anesthetic and placebo-injected groups. Both phases demonstrated that our method of ilioinguinal-iliohypogastric nerve block significantly reduced the amount of iv morphine used by patients during the 24 hr following Cesarean delivery. In the retrospective assessment, morphine use was 49 +/- 30 mg in the block group vs 79 +/- 25 mg in the no block group (P = 0.0063). For the prospective trial, patients who received nerve blocks with bupivacaine had a similar result, self-administering 48 +/- 27 mg of morphine over 24 hr compared to 67 +/- 28 mg administered by patients who received infiltrations of saline. However, despite the significant decrease in morphine use, there was no reduction in opioid-related adverse effects: the incidences of nausea were 41% and 46% (P = 0.70) and for itching were 79% and 63% (P = 0.25) in the placebo and nerve block groups, respectively. A multi-level ilioinguinal-iliohypogastric nerve block technique can reduce the amount of systemic morphine required to control post-Cesarean delivery pain but this reduction was not associated with a reduction of opioid related adverse effects in our study group.
Mariano, Edward R; Ilfeld, Brian M; Cheng, Gloria S; Nicodemus, Hector F; Suresh, Santhanam
Continuous peripheral nerve blocks (CPNB) are effective for postoperative pain management in children in the hospital and at home. CPNB techniques are particularly advantageous when compared with systemic or oral opioids on medical missions to unfamiliar environments with minimal monitoring capacity. In addition, ultrasound-guidance facilitates the placement of perineural catheters in anesthetized children even in the absence of commercially packaged regional anesthesia equipment. We present a series of successful cases employing ultrasound-guided CPNB for postoperative analgesia on medical missions and discuss the impact of this technology on present and future patients in underserved countries.
Barlow, Mark; Carpin, Kimberly; Piña, Edward M.; Casso, Daniel
Summary: This report describes an ultrasound-guided medial and lateral pectoralis nerve block using liposome bupivacaine, performed before the surgical incision, in a patient undergoing submuscular breast augmentation. The anatomic basis and technique are described. This procedure may be offered to patients undergoing submuscular insertion of a breast implant or tissue expander. Advancements in ultrasound guidance allow for more precise anatomic placement of local anesthetic agents. The injection technique used for this procedure resulted in complete relaxation of the pectoralis major, facilitating the surgical dissection and markedly diminishing postsurgical pain and muscle spasms. PMID:25587516
Maher, Dermot P; Serna-Gallegos, Derek; Mardirosian, Rodney; Thomas, Otto J; Zhang, Xiao; McKenna, Robert; Yumul, Roya; Zhang, Vida
The use of multiple-level, single-injection intercostal nerve blocks for pain control following video-assisted thorascopic surgery (VATS) is limited by the analgesic duration of local anesthetics. This study examines whether the combination of perineural and intravenous (IV) dexamethasone will prolong the duration of intraoperatively placed intercostal nerve blocks following VATS compared with IV dexamethasone and a perineural saline placebo. Prospective, double-blind, randomized placebo-controlled trial. Single level-1 academic trauma center. Forty patients undergoing a unilateral VATS under the care of a single surgeon. Patients were randomly assigned to two groups and received an intercostal nerve block containing 1) 0.5% bupivacaine with epinephrine and 1 ml of 0.9% saline or 2) 0.5% bupivacaine with epinephrine and 1 ml of a 4 mg/ml dexamethasone solution. All patients received 8 mg of IV dexamethasone. Group 2 had lower NRS-11 scores at post-operative hours 8 (5.05, SD = 2.13 vs 3.50, SD = 2.50; p = 0.04), 20 (4.30, SD = 2.96 vs 2.26, SD = 2.31; p = 0.02), and 24 (4.53, SD = 1.95 vs 2.26, SD = 2.31; p = 0.02). Equianalgesic opioid requirement was decreased in group 2 at 32 hours (5.78 mg, SD = 5.77 vs 1.67 mg, SD = 3.49; p = 0.02). Group 2 also had greater FEV1 measured at 8, 12, 24, and 44 hours; greater FVC at 24 hours; greater PEF at 28 through 48 hours; and greater FEV1/FVC at 8 and 36 hours. The combination of IV and perineural dexamethasone prolonged the duration of a single-injection bupivacaine intercostal nerve block as measured by NRS-11 compared with IV dexamethasone alone at 24 hours. Reduced NRS-11 at other times, reduced opioid requirements, and increased PFTs were observed in group 2.
Gazzera, Carlo; Fonio, Paolo; Faletti, Riccardo; Dotto, Maria Chiara; Gobbi, Fabio; Donadio, Pierpaolo; Gandini, Giovanni
This paper discusses the technique and preliminary results of right thoracic paravertebral block (TPVB) for percutaneous thermal ablation of liver tumours. Between October 2011 and August 2012 we treated 36 lesions (25 hepatocellular carcinoma and 11 metastases) in 30 patients aged 47-85 years (mean 67.5). Patients received ultrasound (US)-guided injection of 7 ml of naropin 0.75 % in T7, T9 and T11 levels, below the costo-vertebral ligament, until we observed an anterior displacement of the parietal pleura. For the subcapsular lesions, a cervical right phrenic nerve block was associated. The level of analgesia was evaluated during and after the percutaneous procedures with the Numerical Rating Scale. Finally, we investigated statistical correlations between pain and lesions (histological type, site, dimensions), and ablation time and technique (microwave or radiofrequency ablation). Technical success was achieved in all patients. Despite the correct anaesthetic diffusion during the ablation, 10 patients (33.3 %) reported medium/severe pain and intravenous sedation was required. Pain was not found to correlate with any variable. No complications were observed. In most cases, TPVB is a safe and effective technique for conscious anaesthesia during percutaneous thermal ablation of liver tumours. Failures probably derive from left sympathetic and parasympathetic fibre stimulation. We recommend performing a TPVB in the presence of the anaesthetist.
Badiger, Santoshi V.; Desai, Sameer N.
Background: A variety of techniques have been described for the axillary block using nerve stimulator, either with single injection, two, three, or four separate injections. Identification of all the four nerves is more difficult and time-consuming than other methods. Aims: Aim of the present study is to compare success rate, onset, and duration of sensory and motor anesthesia of axillary block using nerve stimulator, either with single injection after identification of any one of the four nerves or four separate injections following identification of each of nerve. Setting and Design: Prospective, randomized, double-blind study. Patients undergoing forearm and hand surgeries under axillary block. Methodology: One hundred patients, aged 18–75 years, were randomly allocated into two groups of 50 each. Axillary block was performed under the guidance of nerve stimulator with a mixture of 18 ml of 1.5% lignocaine and 18 ml of 0.5% bupivacaine. In the first group (n = 50), all 36 ml of local anesthetic was injected after the identification of motor response to any one of the nerves and in Group 2, all the four nerves were identified by the motor response, and 9 ml of local anesthetic was injected at each of the nerves. The success rate of the block, onset, and duration of sensory and motor block was assessed. Statistical Analysis: Categorical variables were compared using the Chi-square test, and continuous variables were compared using independent t-test. Results: The success rate of the block with four injection technique was higher compared to single-injection technique (84% vs. 56%, P = 0.02). Four injection groups had a faster onset of sensory and motor block and prolonged duration of analgesia compared to single-injection group (P < 0.001). There were no significant differences in the incidence of accidental arterial puncture and hemodynamic parameter between the groups. Conclusion: Identification of all the four nerves produced higher success rate and better
Ching, Rosanna C.; Kingham, Paul J.
Peripheral nerve injuries remain problematic to treat, with poor functional recovery commonly observed. Injuries resulting in a nerve gap create specific difficulties for axonal regeneration. Approaches to address these difficulties include autologous nerve grafts (which are currently the gold standard treatment) and synthetic conduits, with the latter option being able to be impregnated with Schwann cells or stem cells which provide an appropriate micro-environment for neuronal regeneration to occur. Transplanting stem cells, however, infers additional risk of malignant transformation as well as manufacturing difficulties and ethical concerns, and the use of autologous nerve grafts and Schwann cells requires the sacrifice of a functioning nerve. A new approach utilizing exosomes, secreted extracellular vesicles, could avoid these complications. In this review, we summarize the current literature on exosomes, and suggest how they could help to improve axonal regeneration following peripheral nerve injury. PMID:26109947
Smistad, Erik; Iversen, Daniel Høyer; Leidig, Linda; Lervik Bakeng, Janne Beate; Johansen, Kaj Fredrik; Lindseth, Frank
Ultrasound-guided regional anesthesia can be challenging, especially for inexperienced physicians. The goal of the proposed methods is to create a system that can assist a user in performing ultrasound-guided femoral nerve blocks. The system indicates in which direction the user should move the ultrasound probe to investigate the region of interest and to reach the target site for needle insertion. Additionally, the system provides automatic real-time segmentation of the femoral artery, the femoral nerve and the two layers fascia lata and fascia iliaca. This aids in interpretation of the 2-D ultrasound images and the surrounding anatomy in 3-D. The system was evaluated on 24 ultrasound acquisitions of both legs from six subjects. The estimated target site for needle insertion and the segmentations were compared with those of an expert anesthesiologist. Average target distance was 8.5 mm with a standard deviation of 2.5 mm. The mean absolute differences of the femoral nerve and the fascia segmentations were about 1-3 mm.
Whether activation of afferent renal nerves contributes to the regulation of arterial pressure and sodium balance has been long overlooked. In normotensive rats, activating renal mechanosensory nerves decrease efferent renal sympathetic nerve activity (ERSNA) and increase urinary sodium excretion, an inhibitory renorenal reflex. There is an interaction between efferent and afferent renal nerves, whereby increases in ERSNA increase afferent renal nerve activity (ARNA), leading to decreases in ERSNA by activation of the renorenal reflexes to maintain low ERSNA to minimize sodium retention. High-sodium diet enhances the responsiveness of the renal sensory nerves, while low dietary sodium reduces the responsiveness of the renal sensory nerves, thus producing physiologically appropriate responses to maintain sodium balance. Increased renal ANG II reduces the responsiveness of the renal sensory nerves in physiological and pathophysiological conditions, including hypertension, congestive heart failure, and ischemia-induced acute renal failure. Impairment of inhibitory renorenal reflexes in these pathological states would contribute to the hypertension and sodium retention. When the inhibitory renorenal reflexes are suppressed, excitatory reflexes may prevail. Renal denervation reduces arterial pressure in experimental hypertension and in treatment-resistant hypertensive patients. The fall in arterial pressure is associated with a fall in muscle sympathetic nerve activity, suggesting that increased ARNA contributes to increased arterial pressure in these patients. Although removal of both renal sympathetic and afferent renal sensory nerves most likely contributes to the arterial pressure reduction initially, additional mechanisms may be involved in long-term arterial pressure reduction since sympathetic and sensory nerves reinnervate renal tissue in a similar time-dependent fashion following renal denervation. PMID:25411364
Kopp, Ulla C
Whether activation of afferent renal nerves contributes to the regulation of arterial pressure and sodium balance has been long overlooked. In normotensive rats, activating renal mechanosensory nerves decrease efferent renal sympathetic nerve activity (ERSNA) and increase urinary sodium excretion, an inhibitory renorenal reflex. There is an interaction between efferent and afferent renal nerves, whereby increases in ERSNA increase afferent renal nerve activity (ARNA), leading to decreases in ERSNA by activation of the renorenal reflexes to maintain low ERSNA to minimize sodium retention. High-sodium diet enhances the responsiveness of the renal sensory nerves, while low dietary sodium reduces the responsiveness of the renal sensory nerves, thus producing physiologically appropriate responses to maintain sodium balance. Increased renal ANG II reduces the responsiveness of the renal sensory nerves in physiological and pathophysiological conditions, including hypertension, congestive heart failure, and ischemia-induced acute renal failure. Impairment of inhibitory renorenal reflexes in these pathological states would contribute to the hypertension and sodium retention. When the inhibitory renorenal reflexes are suppressed, excitatory reflexes may prevail. Renal denervation reduces arterial pressure in experimental hypertension and in treatment-resistant hypertensive patients. The fall in arterial pressure is associated with a fall in muscle sympathetic nerve activity, suggesting that increased ARNA contributes to increased arterial pressure in these patients. Although removal of both renal sympathetic and afferent renal sensory nerves most likely contributes to the arterial pressure reduction initially, additional mechanisms may be involved in long-term arterial pressure reduction since sympathetic and sensory nerves reinnervate renal tissue in a similar time-dependent fashion following renal denervation. Copyright © 2015 the American Physiological Society.
Mailis, Angela; Taenzer, Paul
BACKGROUND: The Special Interest Group of the Canadian Pain Society has produced consensus-based guidelines for the pharmacological management of neuropathic pain. The society aimed to generate an additional guideline for other forms of neuropathic pain treatments. OBJECTIVE: To develop evidence-based recommendations for neuropathic pain interventional treatments. METHODS: A task force was created and engaged the Institute of Health Economics in Edmonton, Alberta, to survey the literature pertaining to multiple treatments. Sufficient literature existed on four interventions only: spinal cord stimulation; epidural injections; intravenous infusions; and nerve blocks. A comprehensive search was conducted for systematic reviews, randomized controlled trials and evidence-based clinical practice guidelines; a critical review was generated on each topic. A modified United States Preventive Services Task Force tool was used for quality rating and grading of recommendations. RESULTS: Investigators reviewed four studies of spinal cord stimulation, 19 studies of intravenous infusions, 14 studies of epidural injections and 16 studies of nerve blocks that met the inclusion criteria. The task force chairs rated the quality of evidence and graded the recommendations. Feedback was solicited from the members of the task force. CONCLUSION: There is sufficient evidence to support recommendations for some of these interventions for selected neuropathic pain conditions. This evidence is, at best, moderate and is often limited or conflicting. Pain practitioners are encouraged to explore evidence-based treatment options before considering unproven treatments. Full disclosure of risks and benefits of the available options is necessary for shared decision making and informed consent. PMID:22606679
Tantry, Thrivikrama Padur; Shetty, Pramal; Shetty, Rithesh; Shenoy, Sunil P
Regional anesthesia is favored in patients who undergo emergency extremity (limb) surgery, and specifically so in the absence of fasting status. In the absence of ultrasonic guidance, the nerve stimulator still remains a valuable tool in performing a brachial block, but its use is difficult in an emergency surgical patient and greater cautious approach is essential. We identified the supraclavicular plexus by the nerve stimulation-motor response technique as follows. Anterior chest muscles contractions, diaphragmatic contraction, deltoid contractions, and posterior shoulder girdle muscle contractions when identified were taken as "negative response" with decreasing stimulating current. A forearm muscle contraction, especially "wrist flexion" and "finger flexion" at 0.5 mA of current was taken as "positive response." If no positive response was identified, the "elbow flexion" was considered as the final positive response for successful drug placement. The series of patients had difficulty for administering both general and regional anesthesia and we considered them as complex scenarios. The risk of the block failure was weighed heavily against the benefits of its success. The described series includes patients who had successful outcomes in the end and the techniques, merits, and risks are highlighted.
Tantry, Thrivikrama Padur; Shetty, Pramal; Shetty, Rithesh; Shenoy, Sunil P.
Regional anesthesia is favored in patients who undergo emergency extremity (limb) surgery, and specifically so in the absence of fasting status. In the absence of ultrasonic guidance, the nerve stimulator still remains a valuable tool in performing a brachial block, but its use is difficult in an emergency surgical patient and greater cautious approach is essential. We identified the supraclavicular plexus by the nerve stimulation-motor response technique as follows. Anterior chest muscles contractions, diaphragmatic contraction, deltoid contractions, and posterior shoulder girdle muscle contractions when identified were taken as “negative response” with decreasing stimulating current. A forearm muscle contraction, especially “wrist flexion” and “finger flexion” at 0.5 mA of current was taken as “positive response.” If no positive response was identified, the “elbow flexion” was considered as the final positive response for successful drug placement. The series of patients had difficulty for administering both general and regional anesthesia and we considered them as complex scenarios. The risk of the block failure was weighed heavily against the benefits of its success. The described series includes patients who had successful outcomes in the end and the techniques, merits, and risks are highlighted. PMID:26417145
Barreveld, Antje; Witte, Jürgen; Chahal, Harkirat; Durieux, Marcel E.; Strichartz, Gary
The use of local anesthetics to reduce acute postoperative pain has a long history, but recent reports have not been systematically reviewed. In addition, the need to include only those clinical studies that meet minimum standards for randomization and blinding must be adhered to. In this review we have applied stringent clinical study design standards to identify publications on the use of perioperative local anesthetics. We first examined several types of peripheral nerve blocks, covering a variety of surgical procedures, and second, for effects of intentionally administered IV local anesthetic (lidocaine) for suppression of postoperative pain. Thirdly, we have examined publications in which vascular concentrations of local anesthetics were measured at different times after peripheral nerve block procedures, noting the incidence when those levels reached ones achieved during intentional IV administration. Importantly, the very large number of studies using neuraxial blockade techniques (epidural, spinal) has not been included in this review but will be dealt with separately in a later review. The overall results showed a strongly positive effect of local anesthetics, by either route, for suppressing postoperative pain scores and analgesic (opiate) consumption. In only a few situations were the effects equivocal. Enhanced effectiveness with the addition of adjuvants was not uniformly apparent. The differential benefits between drug delivery before, during, or immediately after a surgical procedure are not obvious, and a general conclusion is that the significant antihyperalgesic effects occur when the local anesthetic is present during the acute postoperative period, and its presence during surgery is not essential for this action. PMID:23408672
Kalava, Arun; Clendenen, Steven; McKinney, J Mark; Bojaxhi, Elird; Greengrass, Roy A
Background and Aims To assess the efficacy of bilateral thoracic paravertebral nerve blocks (PVB) in providing procedural anesthesia and post-procedural analgesia for placement of percutaneous radiologic gastrostomy tubes (PRG) in patients with amyotrophic lateral sclerosis (ALS). Methods We prospectively observed 10 patients with ALS scheduled for PRG placement that had bilateral thoracic PVBs at thoracic 7, 8, and 9 levels with administration of a mixture of 3 mL of 1% ropivacaine, 0.5 mg/mL dexamethasone, and 5 μg/mL epinephrine at each level. The success of the block was assessed after 10 minutes. PRG placement was done in the interventional radiology suite without sedation. All patients were followed up via phone 24 hours after the procedure. Results All 10 patients had successful placement of PRG with PVBs as the primary anesthetic. Segmental anesthesia over the surgical site in all cases was successful with first attempt of the blocks. Three patients had significant hypotension after the block, requiring boluses of vasopressors and intravenous fluids. All patients reported high levels of satisfaction and sleep quality on the night of the procedure. Conclusions Bilateral thoracic PVBs provided satisfactory procedural anesthesia and post-procedural analgesia, and thus, seem promising as a safe alternative to sedation in ALS patients having PRG placement. PMID:28913488
Zheng, Qingshan; Yang, Xiaolin; Lv, Rong; Ma, Longxiang; Liu, Jin; Zhu, Tao; Zhang, Wensheng
Objective The quaternary lidocaine derivative (QX-314) in combination with bupivacaine can produce long-lasting nerve blocks in vivo, indicating potential clinical application. The aim of the study was to investigate the efficacy, safety, and the optimal formulation of this combination. Methods QX-314 and bupivacaine at different concentration ratios were injected in the vicinity of the sciatic nerve in rats; bupivacaine and saline served as controls (n = 6~10). Rats were inspected for durations of effective sensory and motor nerve blocks, systemic adverse effects, and histological changes of local tissues. Mathematical models were established to reveal drug-interaction, concentration-effect relationships, and the optimal ratio of QX-314 to bupivacaine. Results 0.2~1.5% QX-314 with 0.03~0.5% bupivacaine produced 5.8~23.8 h of effective nerve block; while 0.5% bupivacaine alone was effective for 4 h. No systemic side effects were observed; local tissue reactions were similar to those caused by 0.5% bupivacaine if QX-314 were used < 1.2%. The weighted modification model was successfully established, which revealed that QX-314 was the main active ingredient while bupivacaine was the synergist. The formulation, 0.9% QX-314 plus 0.5% bupivacaine, resulted in 10.1 ± 0.8 h of effective sensory and motor nerve blocks. Conclusion The combination of QX-314 and bupivacaine facilitated prolonged sciatic nerve block in rats with a satisfactory safety profile, maximizing the duration of nerve block without clinically important systemic and local tissue toxicity. It may emerge as an alternative approach to post-operative pain treatment. PMID:28334014
Muthiah, Thilaka; Arora, Mahesh K; Trikha, Anjan; Sunder, Rani A; Prasad, Ganga; Singh, Preet M
Background and Aims: Three-in-one and femoral nerve blocks are proven modalities for postoperative analgesia following anterior cruciate ligament (ACL) reconstruction. The aim of this study was to evaluate the efficacy of magnesium (Mg) as an adjuvant to bupivacaine in 3-in-1 block for ACL reconstruction. Methods: Sixty patients undergoing arthroscopic ACL reconstruction were randomly allocated to Group I (3-in-1 block with 30 ml of 0.25% bupivacaine preceded by 1.5 ml of intravenous [IV] saline), Group II (3-in-1 block with 30 ml of 0.25% bupivacaine preceded by 1.5 ml of solution containing 150 mg Mg IV) or Group III (3-in-1 block with 30 ml containing 0.25% bupivacaine and 150 mg of Mg as adjuvant preceded by 1.5 ml of IV saline). Post-operatively, patients received morphine when visual analogue scale (VAS) score was ≥4. Quantitative parameters were compared using one-way ANOVA and Kruskal–Wallis test and qualitative data were analysed using Chi-square test. Results: Demographics, haemodynamic parameters, intra-operative fentanyl requirement, post-operative VAS scores and total morphine requirement were comparable between groups. Time to first analgesic requirement was significantly prolonged in Group III (789 ± 436) min compared to Group I (466 ± 290 min) and Group II (519 ± 274 min), (P = 0.02 and 0.05). Significantly less number of patients in Group III (1/20) received morphine in the first 6 h post-operatively, compared to Group I (8/20) and Group II (6/20) (P = 0.008 and 0.03). No side effects were observed. Conclusion: Mg as an adjuvant to bupivacaine in 3-in-1 block for ACL reconstruction significantly prolongs the time to first analgesic requirement and reduces the number of patients requiring morphine in the immediate post-operative period. PMID:27512165
Feigl, G C; Dreu, M; Ulz, H; Breschan, C; Maier, C; Likar, R
Interference with the function of the genitofemoral nerve (GFN) and lateral femoral cutaneous nerve (LFCN) represents a significant complication of lumbar sympathetic blocks (LSBs). The nerve topography of the lumbar sympathetic trunk (LST) was investigated to find a possible morphological reason for this. A total of 118 cadavers embalmed by Thiel's method were investigated. The nerves were dissected from their innervation area to their paravertebral origins. Distances of the GFN and the LFCN to the LST were measured at levels L2/3, L3/4, and L4/5, which are the most common levels for LSB. Two hundred and thirteen sides were assessable for the GFN and 151 sides for the LFCN. In 186 cases, the whole GFN (in 20 cases, its femoral branch only) approached the medial margin of the psoas major (PM) and passed the LST laterally at the level of L3/4 and a distance of 0-28 mm (mean distance 8.5 mm; sd 6.7 mm) and ran dorsally between the PM and the vertebral body of L3, reaching the intervertebral foramen L2/3. In three cases, the GFN fused with the LFCN. In 55 cases, the GFN-LST distance was 0-13 mm at L4/5 and in 19 cases, 9-19 mm at L2/3. The LFCN approached the lateral margin of the PM and entered the intervertebral foramen at L2/3 in 141 cases. There is a higher risk of LSB affecting the GFN at L3/4 or L4/5 during neurolysis of the LST due to its topography. The LFCN rarely shows a strong relation to the LST and only when fused with the GFN. © The Author . Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: email@example.com.
Rashmi, H. D.; Komala, H. K.
Background: Ropivacaine, a newer local anesthetic (LA), has been increasingly used nowadays in different concentrations for peripheral nerve blocks. It has lesser cardiac toxicity and higher safety margin when compared to bupivacaine. Dexmedetomidine, a novel α2 agonist, is widely used as adjuvant to LA in peripheral nerve blocks to decrease the time of onset and increase the duration of the block. In this study, we evaluated the effect of dexmedetomidine as an adjuvant with 0.75% ropivacaine for interscalene brachial plexus block using nerve stimulator. Aim: This study aims to know the effect of using dexmedetomidine as an adjuvant to 0.75% ropivacaine in interscalene brachial plexuses block using nerve stimulator. Settings and Designs: Sixty patients scheduled for elective orthopedic surgery of the upper limb under interscalene block were considered in this prospective randomized controlled double-blind study. The study population was randomly divided into two groups with thirty patients in each group by using computerized randomization. Materials and Methods: Group R received 30 ml of 0.75% ropivacaine with 0.5 ml normal saline and Group RD received 30 ml of 0.75% ropivacaine with 50 μg of dexmedetomidine. The onset of sensory and motor blocks, duration of sensory and motor block, and patient satisfaction score were observed. Results: Both the groups were comparable in demographic characteristics. The onset of the sensory and motor block is earlier and statistically significant in Group RD (P < 0.05) when compared to Group R. The duration of sensory and motor blockade were significantly prolonged in Group RD (P < 0.0001). Conclusion: Addition of dexmedetomidine to 0.75% ropivacaine in interscalene brachial plexus block significantly shortened the time of onset of the block and prolongs the duration sensory and motor blockade. PMID:28298772
Dexamethasone as Adjuvant to Bupivacaine Prolongs the Duration of Thermal Antinociception and Prevents Bupivacaine-Induced Rebound Hyperalgesia via Regional Mechanism in a Mouse Sciatic Nerve Block Model
An, Ke; Elkassabany, Nabil M.; Liu, Jiabin
Background Dexamethasone has been studied as an effective adjuvant to prolong the analgesia duration of local anesthetics in peripheral nerve block. However, the route of action for dexamethasone and its potential neurotoxicity are still unclear. Methods A mouse sciatic nerve block model was used. The sciatic nerve was injected with 60ul of combinations of various medications, including dexamethasone and/or bupivacaine. Neurobehavioral changes were observed for 2 days prior to injection, and then continuously for up to 7 days after injection. In addition, the sciatic nerves were harvested at either 2 days or 7 days after injection. Toluidine blue dyeing and immunohistochemistry test were performed to study the short-term and long-term histopathological changes of the sciatic nerves. There were six study groups: normal saline control, bupivacaine (10mg/kg) only, dexamethasone (0.5mg/kg) only, bupivacaine (10mg/kg) combined with low-dose (0.14mg/kg) dexamethasone, bupivacaine (10mg/kg) combined with high-dose (0.5mg/kg) dexamethasone, and bupivacaine (10mg/kg) combined with intramuscular dexamethasone (0.5mg/kg). Results High-dose perineural dexamethasone, but not systemic dexamethasone, combined with bupivacaine prolonged the duration of both sensory and motor block of mouse sciatic nerve. There was no significant difference on the onset time of the sciatic nerve block. There was “rebound hyperalgesia” to thermal stimulus after the resolution of plain bupivacaine sciatic nerve block. Interestingly, both low and high dose perineural dexamethasone prevented bupivacaine-induced hyperalgesia. There was an early phase of axon degeneration and Schwann cell response as represented by S-100 expression as well as the percentage of demyelinated axon and nucleus in the plain bupivacaine group compared with the bupivacaine plus dexamethasone groups on post-injection day 2, which resolved on post-injection day 7. Furthermore, we demonstrated that perineural dexamethasone
Niu, Yuqing; Chen, Kevin C; He, Tao; Yu, Wenying; Huang, Shuiwen; Xu, Kaitian
Nerve guide scaffolds from block polyurethanes without any additional growth factors or protein were prepared using a particle leaching method. The scaffolds of block polyurethanes (abbreviated as PUCL-ran-EG) based on poly(ɛ-caprolactone) (PCL-diol) and poly(ethylene glycol) (PEG) possess highly surface-area porous for cell attachment, and can provide biochemical and topographic cues to enhance tissue regeneration. The nerve guide scaffolds have pore size 1-5 μm and porosity 88%. Mechanical tests showed that the polyurethane nerve guide scaffolds have maximum loads of 4.98 ± 0.35 N and maximum stresses of 6.372 ± 0.5 MPa. The histocompatibility efficacy of these nerve guide scaffolds was tested in a rat model for peripheral nerve injury treatment. Four types of guides including PUCL-ran-EG scaffolds, autograft, PCL scaffolds and silicone tubes were compared in the rat model. After 14 weeks, bridging of a 10 mm defect gap by the regenerated nerve was observed in all rats. The nerve regeneration was systematically characterized by sciatic function index (SFI), histological assessment including HE staining, immunohistochemistry, ammonia silver staining, Masson's trichrome staining and TEM observation. Results revealed that polyurethane nerve guide scaffolds exhibit much better regeneration behavior than PCL, silicone tube groups and comparable to autograft. Electrophysiological recovery was also seen in 36%, 76%, and 87% of rats in the PCL, PUCL-ran-EG, and autograft groups respectively, whilst 29.8% was observed in the silicone tube groups. Biodegradation in vitro and in vivo show proper degradation of the PUCL-ran-EG nerve guide scaffolds. This study has demonstrated that without further modification, plain PUCL-ran-EG nerve guide scaffolds can help peripheral nerve regeneration excellently.
Lee, Michelle; Lineberry, Kyle; Reed, Deborah; Guyuron, Bahman
The third occipital nerve is often encountered during the occipital migraine surgery, however its contribution to migraine headaches is unclear. The objective of this study was to determine whether removing the third occipital nerve plays any role in the clinical outcomes of occipital migraine surgery. A retrospective comparative review was conducted on all occipital migraine headache (Site IV) patients from 1/2000 to 12/2010. Inclusion criteria were: 1) completion of migraine questionnaire, 2) migraine Site IV decompression, and 3) minimum 6 months of follow-up. Patients were divided into those who had the third occipital nerve removed and those who did not. Outcome variables included overall Migraine Headache Index reduction and Site IV pain elimination. 229 patients met the study inclusion criteria. The third occipital nerve removed group (111 patients) and the third occipital nerve not removed group (118 patients) were comparable in terms of age, gender, number of surgical sites, and statistically well matched regarding preoperative headache characteristics. Comparing the third occipital nerve removed to the third occipital nerve not removed group, Migraine headache index reduction was 63% vs. 64%. Patients experiencing migraine headache elimination (third occipital nerve removed 26% vs. third occipital nerve not removed 29%; p=0.45) and surgery success with at least 50% reduction in migraine headache (third occipital nerve removed 80% vs. third occipital nerve not removed 81%; p=0.82) were also similar. There was also no difference between the two groups in symptomatic neuroma formation. Site IV specific pain elimination was similar between the two groups (third occipital nerve removed 58% vs. third occipital nerve not removed 64%; p=0.54). Removal of the third occipital nerve did not alter migraine surgery success. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Chan, Ee-Yuee; Fransen, Marlene; Parker, David A; Assam, Pryseley N; Chua, Nelson
Total knee replacement (TKR) is a common and often painful operation. Femoral nerve block (FNB) is frequently used for postoperative analgesia. To evaluate the benefits and risks of FNB used as a postoperative analgesic technique relative to other analgesic techniques among adults undergoing TKR. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) 2013, Issue 1, MEDLINE, EMBASE, CINAHL, Web of Science, dissertation abstracts and reference lists of included studies. The date of the last search was 31 January 2013. We included randomized controlled trials (RCTs) comparing FNB with no FNB (intravenous patient-controlled analgesia (PCA) opioid, epidural analgesia, local infiltration analgesia, and oral analgesia) in adults after TKR. We also included RCTs that compared continuous versus single-shot FNB. Two review authors independently performed study selection and data extraction. We undertook meta-analysis (random-effects model) and used relative risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) or standardized mean differences (SMDs) for continuous outcomes. We interpreted SMDs according to rule of thumb where 0.2 or smaller represents a small effect, 0.5 a moderate effect and 0.8 or larger, a large effect. We included 45 eligible RCTs (2710 participants) from 47 publications; 20 RCTs had more than two allocation groups. A total of 29 RCTs compared FNB (with or without concurrent treatments including PCA opioid) versus PCA opioid, 10 RCTs compared FNB versus epidural, five RCTs compared FNB versus local infiltration analgesia, one RCT compared FNB versus oral analgesia and four RCTs compared continuous versus single-shot FNB. Most included RCTs were rated as low or unclear risk of bias for the aspects rated in the risk of bias assessment tool, except for the aspect of blinding. We rated 14 (31%) RCTs at high risk for both participant and assessor blinding and rated eight (18%) RCTs at high risk for one blinding aspect.Pain at
Stocum, David L
Nerve axons and the apical epidermal cap (AEC) are both essential for the formation of an accumulation blastema by amputated limbs of urodele salamanders. The AEC forms in the absence of axons, but is not maintained, and blastema formation fails. Growth stages of the blastema become nerve-independent for morphogenesis, but remain dependent on the nerve for blastema growth. Denervated growth stage blastemas form smaller than normal skeletal parts, owing to diminished mitosis, but form the full proximodistal array of skeletal elements. This difference in nerve dependency of morphogenesis and proliferation is hypothesized to be the result of a dependence of the AEC on nerves for blastema cell proliferation but not for blastema morphogenesis. Regenerating axons induce the synthesis and secretion of the anterior gradient protein (AGP) by distal Schwann cells during dedifferentiation and by the gland cells of the AEC during blastema growth stages. AGP promotes the regeneration of a denervated limb to digit stages when electroporated into the limb during dedifferentiation. Once a critical mass of blastema cells has been attained, the blastema can undergo morphogenesis in the absence of the nerve, but the regenerate will be a miniature, because the nerve is no longer inducing the AEC to carry out its AGP-mediated proliferative function. AGP expression by both Schwann cells and the AEC is induced by axons, but the nature of the inductive agent is unclear.
Tang, Yongguo; Kang, Junfang; Zhang, Yu; Zhang, Xuejun
Greater occipital nerve (GON) block may be a promising approach to treat migraine. However, the results remained controversial. We conducted a systematic review and meta-analysis to explore the efficacy of GON block in migraine patients. PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) assessing the efficacy of GON block versus placebo in migraine patients were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. Meta-analysis was performed using the random-effect model. Six RCTs were included in the meta-analysis. Overall, compared with control intervention in migraine patients, GON block intervention was found to significantly reduce pain score (Std. mean difference=-0.51; 95% CI=-0.81 to -0.21; P=0.0008), number of headache days (Std. mean difference=-0.68; 95% CI=-1.02 to -0.35; P<0.0001), and medication consumption (Std. mean difference=-0.35; 95% CI=-0.67 to -0.02; P=0.04), but demonstrated no influence on duration of headache per four weeks (Std. mean difference=-0.07; 95% CI=-0.41 to 0.27; P=0.70). Compared to control intervention, GON block intervention can significantly alleviate pain, reduce the number of headache days and medication consumption, but have no significant influence on the duration of headache per four weeks for migraine patients. Copyright © 2017. Published by Elsevier Inc.
Danelli, Giorgio; Ghisi, Daniela; Fanelli, Andrea; Ortu, Andrea; Moschini, Elisa; Berti, Marco; Ziegler, Stefanie; Fanelli, Guido
We tested the hypothesis that ultrasound (US) guidance may reduce the minimum effective anesthetic volume (MEAV(50)) of 1.5% mepivacaine required to block the sciatic nerve with a subgluteal approach compared with neurostimulation (NS). After premedication and single-injection femoral nerve block, 60 patients undergoing knee arthroscopy were randomly allocated to receive a sciatic nerve block with either NS (n = 30) or US (n = 30). In the US group, the sciatic nerve was localized between the ischial tuberosity and the greater trochanter. In the NS group, the appropriate muscular response (foot plantar flexion or inversion) was elicited (1.5 mA, 2 Hz, 0.1 ms) and maintained to
Joy, Binu; Sandhyala, Abhilash; Naiknaware, Kiran; Ray, Brijesh; Vijayakumar
Introduction Laser ablation and sclerotherapy, as minimally invasive alternatives to surgery for varicose veins, have good efficacy, safety and cosmetic result. Some form of anaesthesia is generally used for pain control. Aim To describe the technique and evaluate the efficacy and safety of femoral, saphenous and sciatic nerve blocks in isolation or in combination for analgesia during laser ablation and sclerotherapy for lower limb varicose veins. Materials and Methods In this prospective observational study, over a period of 33 months, in 856 limbs of 681 patients with varicose veins, ultrasound guided femoral, saphenous and sciatic nerve blocks for analgesia were performed in 769, 808 and 52 instances respectively; following which, endovenous laser ablation, sclerotherapy or combination of both were carried out using standard practice. After completion of the procedure, Visual Analogue Pain Scale (VAS) was used for pain assessment, and muscle weakness was assessed clinically. Results Nerve blocks could be successfully performed in all patients. Observed pain scores were 0 or 1 in 591 (69%), 2 or 3 in 214 (25%) and 4 in 51 (9%) legs with no score more than 4. Higher grades of pain were noted in femoral blocks during early stages of our learning curve. Mild to moderate muscle weakness was observed in 163 (2%) and 7 (13%) patients who underwent femoral and sciatic block respectively, which persisted for an average of two and a half hours and none beyond four and a half hours; saphenous nerve being a pure sensory nerve, did not cause motor weakness. Conclusion For analgesia during laser ablation and/or sclerotherapy of varicose veins, ultrasound guided nerve blocks can be easily and quickly performed. They provide excellent pain relief and comfort to the patient and to the operator; and they do not cause any additional complication. PMID:28050474
Matthews, Rachel; Drum, Melissa; Reader, Al; Nusstein, John; Beck, Mike
The purpose of this prospective study was to determine the anesthetic efficacy of the supplemental buccal infiltration injection of a cartridge of 4% articaine with 1:100,000 epinephrine in mandibular posterior teeth diagnosed with irreversible pulpitis when the conventional inferior alveolar nerve (IAN) block failed. Fifty-five emergency patients, diagnosed with irreversible pulpitis of a mandibular posterior tooth, received an IAN block and had moderate to severe pain on endodontic access. An infiltration of a cartridge of 4% articaine with 1:100,000 epinephrine was administered buccal to the tooth requiring endodontic treatment. Success of the infiltration injection was defined as no pain or mild pain on endodontic access or instrumentation. The results showed that anesthetic success was obtained in 58% of the mandibular posterior teeth. We can conclude that when the IAN block fails to provide profound pulpal anesthesia, the supplemental buccal infiltration injection of a cartridge of 4% articaine with 1:100,000 epinephrine would be successful 58% of the time for mandibular posterior teeth in patients presenting with irreversible pulpitis. Unfortunately, the modest success rate would not provide predictable pulpal anesthesia for all patients requiring profound anesthesia.
Gungor, Semih; Rana, Bhumika; Fields, Kara; Bae, James J; Mount, Lauren; Buschiazzo, Valeria; Storm, Hanne
There is a lack of objective methods for determining the achievement of sympathetic block. This study validates the skin conductance monitor (SCM) as an end point indicator of successful sympathetic blockade as compared with traditional monitors. This interventional study included 13 patients undergoing 25 lumbar sympathetic blocks to compare time to indication of successful blockade between the SCM indices and traditional measures, clinically visible hyperemia, clinically visible engorgement of veins, subjective skin temperature difference, unilateral thermometry monitoring, bilateral comparative thermometry monitoring, and change in waveform amplitude in pulse oximetry plethysmography, within a 30-minute observation period. Differences in the SCM indices were studied pre- and postblock to validate the SCM. SCM showed substantially greater odds of indicating achievement of sympathetic block in the next moment (i.e., hazard rate) compared with all traditional measures (clinically visible hyperemia, clinically visible engorgement of veins, subjective temperature difference, unilateral thermometry monitoring, bilateral comparative thermometry monitoring, and change in waveform amplitude in pulse oximetry plethysmography; P ≤ 0.011). SCM indicated successful block for all (100%) procedures, while the traditional measures failed to indicate successful blocks in 16-84% of procedures. The SCM indices were significantly higher in preblock compared with postblock measurements ( P < 0.005). This preliminary study suggests that SCM is a more reliable and rapid response indicator of a successful sympathetic blockade when compared with traditional monitors.
Brattwall, Metha; Jildenstål, Pether; Warrén Stomberg, Margareta; Jakobsson, Jan G.
Upper extremity blocks are useful as both sole anaesthesia and/or a supplement to general anaesthesia and they further provide effective postoperative analgesia, reducing the need for opioid analgesics. There is without doubt a renewed interest among anaesthesiologists in the interscalene, supraclavicular, infraclavicular, and axillary plexus blocks with the increasing use of ultrasound guidance. The ultrasound-guided technique visualising the needle tip and solution injected reduces the risk of side effects, accidental intravascular injection, and possibly also trauma to surrounding tissues. The ultrasound technique has also reduced the volume needed in order to gain effective block. Still, single-shot plexus block, although it produces effective anaesthesia, has a limited duration of postoperative analgesia and a number of adjuncts have been tested in order to prolong analgesia duration. The addition of steroids, midazolam, clonidine, dexmedetomidine, and buprenorphine has been studied, all being off-label when administered by perineural injection, and the potential neurotoxicity needs further study. The use of perineural catheters is an effective option to improve and prolong the postoperative analgesic effect. Upper extremity plexus blocks have an obvious place as a sole anaesthetic technique or as a powerful complement to general anaesthesia, reducing the need for analgesics and hypnotics intraoperatively, and provide effective early postoperative pain relief. Continuous perineural infusion is an effective option to prolong the effects and improve postoperative quality. PMID:27239291
Scholz, Joachim; Broom, Daniel C; Youn, Dong-Ho; Mills, Charles D; Kohno, Tatsuro; Suter, Marc R; Moore, Kimberly A; Decosterd, Isabelle; Coggeshall, Richard E; Woolf, Clifford J
We show that transsynaptic apoptosis is induced in the superficial dorsal horn (laminas I-III) of the spinal cord by three distinct partial peripheral nerve lesions: spared nerve injury, chronic constriction, and spinal nerve ligation. Ongoing activity in primary afferents of the injured nerve and glutamatergic transmission cause a caspase-dependent degeneration of dorsal horn neurons that is slow in onset and persists for several weeks. Four weeks after spared nerve injury, the cumulative loss of dorsal horn neurons, determined by stereological analysis, is >20%. GABAergic inhibitory interneurons are among the neurons lost, and a marked decrease in inhibitory postsynaptic currents of lamina II neurons coincides with the induction of apoptosis. Blocking apoptosis with the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD) prevents the loss of GABAergic interneurons and the reduction of inhibitory currents. Partial peripheral nerve injury results in pain-like behavioral changes characterized by hypersensitivity to tactile or cold stimuli. Treatment with zVAD, which has no intrinsic analgesic properties, attenuates this neuropathic pain-like syndrome. Preventing nerve injury-induced apoptosis of dorsal horn neurons by blocking caspase activity maintains inhibitory transmission in lamina II and reduces pain hypersensitivity.
Arnholz, Mareike; Hungerbühler, Stephan; Weil, Clarissa; Schütter, Alexandra F; Rohn, Karl; Tünsmeyer, Julia; Kästner, Sabine B R
Comparison of ultrasound-guided femoral and sciatic nerve block versus epidural anaesthesia with bupivacaine and morphine for orthopaedic surgery of the pelvic limb in dogs with respect to analgesic effectiveness, clinical utility and side effects. The study included 22 dogs (American Society of Anesthesiologists, ASA grades I and II) undergoing orthopaedic surgery distal to the mid-femoral bone. The study was designed as a randomized, prospective, blinded clinical trial. All dogs were randomly assigned to receive 0.5 mg/kg bupivacaine (0.5%) and 0.1 mg/kg morphine sulphate (1%) either as epidural anaesthesia (group EPI) or by ultrasound-guided femoral and sciatic nerve block (group LA). During surgery, the heart rate, respiratory rate, mean arterial pressure (MAP), end-tidal isoflurane concentrations and dose of rescue analgesia (fentanyl boluses of 5 µg/kg i. v.) were measured. Pain severity was scored (short form of the Glasgow Composite Measure Pain Scale, GCMPS) before surgery and postoperatively at 2, 4, 6, 12 and 24 hours after extubation. Post-operative rescue analgesia consisted of methadone (0.2 mg/kg i. v.), and was applied when the GCMPS > 6. For statistical analysis, the Chi-square, Fisher, and Wilcoxon tests and one- and two-way ANOVA were applied. Differences were considered statistically significant at p < 0.05. Only the MAP was significantly different between the two treatment groups. Intra- and postoperative MAP of group LA (111.2 ± 11.2 mmHg and 119.3 ± 18.2 mmHg, respectively) was higher than in group EPI (86.6 ± 8.7 mmHg and 95.2 ± 13.1 mmHg, respectively). None of the dogs developed urinary retention or ambulatory deficits when completely recovered from anaesthesia. No other side effects were noted. In conclusion, femoral and sciatic nerve blocks and epidural anaesthesia ensure comparable analgesic effects in canine patients undergoing orthopaedic surgery of the pelvic limb. The lower mean arterial blood pressure of
Warren, Victor T; Fisher, Anson G; Rivera, Eric M; Saha, Pooja T; Turner, Blake; Reside, Glenn; Phillips, Ceib; White, Raymond P
To assess outcomes for pulpal anesthesia and pain on injection for buffered 1% lidocaine with 1:100,000 epinephrine (EPI) versus non-buffered 2% lidocaine with 1:100,000 EPI. In a randomized cross-over trial approved by the institutional review board, buffered 1% lidocaine with 1:100,000 EPI was compared with non-buffered 2% lidocaine with 1:100,000 EPI. After mandibular nerve block with buffered lidocaine 40 mg or non-buffered lidocaine 80 mg, patients reported responses at the mandibular first molar and canine after cold and electrical pulp testing (EPT). Patients also reported pain on injection with a 10-point Likert-type scale. Teeth were tested before nerve block and at 30-minute intervals until a positive response returned. Two weeks later, patients were tested with the alternate drug combinations. The same outcomes were assessed. Predictor variables were alternate drug formulations. Outcome variables were patients' responses to cold and EPT stimulation of the mandibular first molar and canine and pain on injection. An assessment of treatment difference was performed using Wilcoxon rank-sum tests with Proc NPAR1WAY (SAS 9.3, SAS Institute, Cary, NC). Significance was set at a P value less than .05. Fifty-seven percent of patients were women and 43% were men. Seventy percent were Caucasian, 17% were African American, and 13% had another ethnicity. Median age was 25 years (interquartile range [IQR], 21-26 yr) and median body weight was 140 lbs (IQR, 120-155 lbs). After the cold test and EPT, the time to sensation return for the molar or canine was not statistically different between the 2 drug formulations. Patients reported significantly lower pain scores with the buffered versus non-buffered drug (P < .01). After mandibular nerve block, buffered 1% lidocaine with EPI can produce similar clinical outcomes for duration of pulpal anesthesia as non-buffered 2% lidocaine with EPI and lower pain on injections, which are a potential benefit to patients
Genet, F; Schnitzler, A; Droz-Bartholet, F; Salga, M; Tatu, L; Debaud, C; Denormandie, P; Parratte, B
Botulinum Toxin A has been the main treatment for spasticity since the beginning of the 1990s. Surprisingly, there is still no consensus regarding injection parameters or, importantly, how to determine which muscles to target to improve specific functions. The aim of this study was to develop a systematic approach to determine this, using the example of the arm flexion pattern. We first determined anatomical landmarks for selective motor block of the brachialis nerve, using 20 forearms from 10 fresh cadavers in Ecole Européenne de Chirurgie and a university-based dissection centre, Paris, France. We then carried out selective blocks of the motor nerves to the brachialis, brachioradialis and biceps brachii in patients with stroke with an arm flexion pattern, in a University Rehabilitation Hospital, Garches, France. We measured: the resting angle of the elbow angle in standing (manual goniometer), active and passive range of extension, and spasticity using the Held and Tardieu and the Modified Ashworth scales. Range of passive elbow extension was also measured with the shoulder in 90° of flexion. The resting angle of the elbow in standing decreased by 35.0° (from 87.6 ± 23.7 to 52.6 ± 24.2°) with inhibition of brachialis, by a further 3.9° (from 52.6 ± 24.2 to 48.7 ± 23.7°) with inhibition of brachioradialis and a further 14.5° (from 48.7 ± 23.7to 34.2 ± 20.7°) with inhibition of biceps brachii. These results were consistent with the clinical evaluation of passive elbow range of motion with the shoulder at 90°. Sequential blocking of the nerves to the three main elbow flexors revealed that the muscle that limited elbow extension the most, was brachialis. This muscle should be the main target to improve the arm flexion pattern. These results show that it is important not simply to inject the most superficial or powerful muscles to treat a spastic deformity. A comprehensive assessment is required. The strategy proposed in this paper should
Kozak, Megan; Weylin Sternglanz, R; Viswanathan, Uma; Wegner, Daniel M
This research examined the role of thought suppression in the formation of mental blocks. In Experiment 1, participants were asked to generate a series of creative associates for two target words after initially suppressing a word that was semantically related to one of the two target words. Participants produced fewer responses, and experienced a greater sensation of being mentally blocked, when attempting to produce associates for the target word that was semantically related to the suppressed word. In Experiment 2, participants either thought about or suppressed a series of words prior to completing a word fragment completion task. Each word either corresponded exactly to one of the word fragment solutions (target primes) or resembled one of the solutions but was slightly different in its orthographic properties (negative primes). Participants performed most poorly on the items for which they had initially suppressed negative primes.
Meng, Lingbin; Jiang, Xin; Ji, Rui
Taste system is a perfect system to study degeneration and regeneration after nerve injury because the taste system is highly plastic and the regeneration is robust. Besides, degeneration and regeneration can be easily measured since taste buds arise in discrete locations, and nerves that innervate them can be accurately quantified. Neurotrophins are a family of proteins that regulate neural survival, function, and plasticity after nerve injury. Recent studies have shown that neurotrophins play an important role in the developmental and mature taste system, indicating neurtrophin might also regulate taste system following gustatory nerve injury. This review will summarize how taste system degenerates and regenerates after gustatory nerve cut and conclude potential roles of neurotrophin in regulating the process.
Morales-Muñoz, C; Sánchez-Ramos, J L; Díaz-Lara, M D; González-González, J; Gallego-Alonso, I; Hernández-Del-Castillo, M S
Total knee replacement is usually a very painful procedure. A single-dose of femoral nerve block has been shown to provide similar analgesia to an epidural, with fewer side effects, but limited in time. To compare the analgesia provided by dexamethasone used at perineural level in the femoral nerve block after total knee replacement with the one used at intravenous level, and with that of a control group. A prospective, randomised, double-blind controlled trial was conducted on 81 patients randomly assigned to one of three groups: 1)IV dexamethasone (8mg); 2)perineural dexamethasone (8mg), and 3)placebo. All patients received 20ml of ropivacaine 0.5% for femoral nerve block. The primary outcome was the duration of the sensory-analgesic block of the femoral nerve block. The secondary outcomes included pain intensity measurements, patient satisfaction, and incidence of complications. Randomisation was effective. Analgesia duration was significantly higher (P<.0001) in the perineural dexamethasone group (mean 1152.2min, 95% confidence interval [95% CI]: 756.9-1547.6) in comparison with the control group (mean 186min, 95%CI: 81.2-292) and dexamethasone IV group (mean 159.4min, 95%CI: 109.8-209). Postoperative pain, complications and side effects were also lower in this group. Dexamethasone prolongs sensory block of single dose of femoral nerve block using ropivacaine. It also provides better analgesia and patient satisfaction, with fewer side effects. Copyright © 2016 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.
Han, Kyung Ream; Chae, Yun Jeong; Lee, Jung Dong; Kim, Chan
Trigeminal nerve block (Tnb) with alcohol for trigeminal neuralgia (TN) may not be used widely as a percutaneous procedure for medically intractable TN in recent clinical work, because it has been considered having a limited duration of pain relief, a decrease in success rate and increase in complications on repeated blocks. To evaluate the clinical outcome of the Tnb with alcohol in the treatment of medically intractable TN. Six hundred thirty-two patients were diagnosed with TN between March 2000 and February 2010. Four hundred sixty-five out of 632 underwent Tnb with alcohol under a fluoroscope. Pain relief duration were analyzed and compared in the individual branch blocks. Outcomes were compared between patients with and without a previous Tnb with alcohol. Tnb with alcohol were performed in a total 710 (1(st)-465, 2(nd)-155, 3(rd)-55, 4(th)-23, 5(th)-8, 6(th)-4) cases for a series of consecutive 465 patients during the study period. Forty hundred sixty two out of the 465 patients experienced immediate complete pain relief (99%) at the first Tnb. Of the 465 patients, 218 patients (46.9%) did not require any further treatment after the first Tnb with alcohol during an entire study period. One hundred fifty nine (34.2 %) out of the 465 patients experienced recurring pain after the first block, among whom 155 patients received subsequent blocks, and the remaining 4 patients decided to take medication. According to the Kaplan-Meier analysis, the probabilities of remaining pain relief for 1, 2, 3, and 5 years after the procedures were 86.2%, 65.5%, 52.5%, and 33.4%, respectively. There was no significant difference in the probability of pain relief duration between patients with and without previous Tnb with alcohol. Median (95% CI) pain relief durations of the first and repeated blocks were 39 (36-51) and 37 (28-54) months, respectively. There was no significant difference in occurrence of complications between patients with and without previous Tnb with alcohol
Han, Kyung Ream; Chae, Yun Jeong; Lee, Jung Dong; Kim, Chan
Background: Trigeminal nerve block (Tnb) with alcohol for trigeminal neuralgia (TN) may not be used widely as a percutaneous procedure for medically intractable TN in recent clinical work, because it has been considered having a limited duration of pain relief, a decrease in success rate and increase in complications on repeated blocks. Objectives: To evaluate the clinical outcome of the Tnb with alcohol in the treatment of medically intractable TN. Methods: Six hundred thirty-two patients were diagnosed with TN between March 2000 and February 2010. Four hundred sixty-five out of 632 underwent Tnb with alcohol under a fluoroscope. Pain relief duration were analyzed and compared in the individual branch blocks. Outcomes were compared between patients with and without a previous Tnb with alcohol. Results: Tnb with alcohol were performed in a total 710 (1st-465, 2nd-155, 3rd-55, 4th-23, 5th-8, 6th-4) cases for a series of consecutive 465 patients during the study period. Forty hundred sixty two out of the 465 patients experienced immediate complete pain relief (99%) at the first Tnb. Of the 465 patients, 218 patients (46.9%) did not require any further treatment after the first Tnb with alcohol during an entire study period. One hundred fifty nine (34.2 %) out of the 465 patients experienced recurring pain after the first block, among whom 155 patients received subsequent blocks, and the remaining 4 patients decided to take medication. According to the Kaplan-Meier analysis, the probabilities of remaining pain relief for 1, 2, 3, and 5 years after the procedures were 86.2%, 65.5%, 52.5%, and 33.4%, respectively. There was no significant difference in the probability of pain relief duration between patients with and without previous Tnb with alcohol. Median (95% CI) pain relief durations of the first and repeated blocks were 39 (36-51) and 37 (28-54) months, respectively. There was no significant difference in occurrence of complications between patients with and
Elkassabany, Nabil M; Antosh, Sean; Ahmed, Moustafa; Nelson, Charles; Israelite, Craig; Badiola, Ignacio; Cai, Lu F; Williams, Rebekah; Hughes, Christopher; Mariano, Edward R; Liu, Jiabin
Adductor canal block (ACB) has emerged as an appealing alternative to femoral nerve block (FNB) that produces a predominantly sensory nerve block by anesthetizing the saphenous nerve. Studies have shown greater quadriceps strength preservation with ACB compared with FNB, but no advantage has yet been shown in terms of fall risk. The Tinetti scale is used by physical therapists to assess gait and balance, and total score can estimate a patient's fall risk. We designed this study to test the primary hypothesis that FNB results in a greater proportion of "high fall risk" patients postoperatively using the Tinetti score compared with ACB. After institutional review board approval, informed written consent to participate in the study was obtained. Patients undergoing primary unilateral total knee arthroplasty were eligible for enrollment in this double-blind, randomized trial. Patients received either an ACB or FNB (20 mL of 0.5% ropivacaine) with catheter placement (8 mL/h of 0.2% ropivacaine) in the setting of multimodal analgesia. Continuous infusion was stopped in the morning of postoperative day (POD)1 before starting physical therapy (PT). On POD1, PT assessed the primary outcome using the Tinetti score for gait and balance. Patients were considered to be at high risk of falling if they scored <19. Secondary outcomes included manual muscle testing of the quadriceps muscle strength, Timed Up and Go (TUG) test, and ambulation distance on POD1 and POD2. The quality of postoperative analgesia and the quality of recovery were assessed with American Pain Society Patient Outcome Questionnaire Revised and Quality of Recovery-9 questionnaire, respectively. Sixty-two patients were enrolled in the study (31 ACB and 31 FNB). No difference was found in the proportion of "high fall risk" patients on POD1 (21/31 in the ACB group versus 24/31 in the FNB group [P = 0.7]; relative risk, 1.14 [95% confidence interval, 0.84-1.56]) or POD2 (7/31 in the ACB versus 14/31 in the FNB
Wang, Chun-Guang; Ding, Yan-Ling; Han, Ai-Ping; Hu, Chang-Qing; Hao, Shi; Zhang, Fang-Fang; Li, Yong-Wang; Liu, Hu; Han, Zhe; Guo, De-Li; Zhang, Zhi-Qiang
The ischemia necrosis of limb frequently requires surgery of amputation. Lumbar plexus and sciatic nerve block is an ideal intra-operative anesthetic and post-operative antalgic technique for patients of amputation, especially for high-risk patients who have severe cardio-cerebrovascular diseases. However, the duration of analgesia of peripheral nerve block is hardly sufficient to avoid the postoperative pain and the usage of opioids. In this case, a 79-year-old man, with multiple cerebral infarcts, congestive heart failure, atrial flutter and syncope, was treated with an above knee amputation because of ischemia necrosis of his left lower limb. Dexmedetomidine 1 μg/kg was added to 0.33% ropivacaine for lumbar plexus and sciatic nerve block in this case for intra-operative anesthesia and post-operative analgesia. The sensory function was blocked fully for surgery and the duration of analgesia maintained 26 hours with haemodynamic stability and moderate sedation. The patient did not complain pain and require any supplementary analgesics after surgery. This case showed that adding 1 μg/kg dexmedetomidine to ropivacaine for lumbar plexus and sciatic nerve block may be a feasible and safe technique for high-risk patients for lower limb surgery of amputation.
Wang, Chun-Guang; Ding, Yan-Ling; Han, Ai-Ping; Hu, Chang-Qing; Hao, Shi; Zhang, Fang-Fang; Li, Yong-Wang; Liu, Hu; Han, Zhe; Guo, De-Li; Zhang, Zhi-Qiang
The ischemia necrosis of limb frequently requires surgery of amputation. Lumbar plexus and sciatic nerve block is an ideal intra-operative anesthetic and post-operative antalgic technique for patients of amputation, especially for high-risk patients who have severe cardio-cerebrovascular diseases. However, the duration of analgesia of peripheral nerve block is hardly sufficient to avoid the postoperative pain and the usage of opioids. In this case, a 79-year-old man, with multiple cerebral infarcts, congestive heart failure, atrial flutter and syncope, was treated with an above knee amputation because of ischemia necrosis of his left lower limb. Dexmedetomidine 1 μg/kg was added to 0.33% ropivacaine for lumbar plexus and sciatic nerve block in this case for intra-operative anesthesia and post-operative analgesia. The sensory function was blocked fully for surgery and the duration of analgesia maintained 26 hours with haemodynamic stability and moderate sedation. The patient did not complain pain and require any supplementary analgesics after surgery. This case showed that adding 1 μg/kg dexmedetomidine to ropivacaine for lumbar plexus and sciatic nerve block may be a feasible and safe technique for high-risk patients for lower limb surgery of amputation. PMID:26550393
Dao, Thuan; Amaro-Driedger, David; Mehta, Jaideep
Raynaud's syndrome has been treated medically and invasively, sometimes with regional anesthesia leading up to sympathectomy. We demonstrate that regional anesthesia was in this case a useful technique that can allow some patients to find temporary but significant relief from symptoms of Raynaud's syndrome exacerbation. We present a 43-year-old woman with Raynaud's syndrome secondary to lupus who was treated with bilateral popliteal nerve block catheters for ischemic pain and necrosis of her feet; this led to almost immediate resolution of her pain and return of color and function of her feet. While medical management should continue to be a front-line treatment for Raynaud's syndrome, regional anesthesia can be useful in providing rapid dissipation of symptoms and may thus serve as a viable option for short-term management of this syndrome.
Ng, Fu-Yuen; Ng, Jacobus Kwok-Fu; Chiu, Kwong-Yuen; Yan, Chun-Hoi; Chan, Chi-Wing
This study compares the efficacy of pain control using continuous femoral nerve block (FNB) and multimodal periarticular soft tissue injection. This is a randomized, crossover, clinical trial. Sixteen patients having bilateral osteoarthritis of the knee scheduled for staged total knee arthroplasty were randomized to receive either FNB (0.2% ropivacaine), via indwelling catheter for 72 hours, or multimodal periarticular soft tissue injection in the first stage. In the second stage, they received the opposite treatment. The primary outcome measure was morphine consumption by patient-controlled analgesia in the first 72 hours postoperatively. Cumulative morphine consumption as well as rest pain and motion pain in the first 72 hours was comparable between the 2 groups. The functional outcomes did not differ significantly. We conclude that multimodal periarticular soft tissue injection provides comparable analgesia to continuous FNB after total knee arthroplasty.
Hart, Emma C; Wallin, B Gunnar; Curry, Timothy B; Joyner, Michael J; Karlsson, Tomas; Charkoudian, Nisha
Abstract Sympathetic baroreflex sensitivity (BRS) is greater during decreasing compared to increasing diastolic blood pressure (DBP) in young men and women. In older men and women there is no difference in sympathetic BRS to increasing and decreasing DBP. We investigated whether the sensitivity of the central nervous system to increasing and decreasing DBP is dependent upon baseline muscle sympathetic nerve activity (MSNA). We hypothesised that the difference in sympathetic BRS between falling and rising segments of DBP would be positively related to baseline MSNA in 30 young men, 21 young women, 14 older men and 14 postmenopausal women. MSNA was measured using peroneal microneurography and BRS was measured using the spontaneous baroreflex threshold technique. On average, sympathetic BRS was greater during decreasing compared to increasing DBP in young men (P < 0.05) and women (P < 0.05). In older men and women, mean sympathetic BRS was similar in response to increasing and decreasing DBP. The difference (delta) between the falling and rising BRS correlated with baseline MSNA in young (r = 0.58, P < 0.05) and older men (r = 0.66, P < 0.05) and postmenopausal women (r = 0.74, P < 0.05). Thus, all men, and older women, with higher BRS to falling DBP had lower baseline MSNA. This relationship was not observed in young women (r = 0.14, P > 0.05). In summary, baseline MSNA plays a role in determining sympathetic BRS to falling and rising DBP in young and older men and postmenopausal women, but not in young women. This relationship is consistent with a decreased potential for sympathoexcitation in people with higher resting MSNA. Furthermore, the lack of relationship in young women suggests important contributions of sex hormones to differential responses of MSNA to falling and rising pressures. PMID:21540345
Birder, Lori A.; Wolf-Johnston, Amanda; Griffiths, Derek; Resnick, Neil M.
Aims To test whether nerve growth factor (NGF) concentration in human bladder urothelium/suburothelium is related to detrusor overactivity (DO), bladder sensation, detrusor contractility, or other aspects of lower urinary tract function. Materials and Methods Concentration of NGF was measured (using ELISA) in superficial bladder biopsies from 27 women (mean age 52 years, range 22–82) after comprehensive videourodynamics and bladder diary. Approximately half (12/27) showed clear DO and half did not. Results There was no evidence for increased NGF concentration in subjects with DO (association negative by Mann–Whitney test, P = 0.23). NGF was not significantly associated with two measures of detrusor contractility (Spearman’s r = −0.29, P = 0.17; r = −0.20, P = 0.33); nor with four measures inversely related to sensation: volume at strong desire to void and maximum capacity on cystometry (r = −0.13, P = 0.53; r = −0.23, P = 0.28), and maximum voided volume and mean daytime voided volume on bladder diary (r = −0.29, P = 0.16; r = −0.16, P = 0.44). It was significantly associated with 24-hr urine output on bladder diary (Spearman’s r = −0.55, P = 0.004). Conclusions Elevated NGF levels in human urothelium/suburothelium are not strongly associated with DO, detrusor contractility or increased bladder sensation. NGF levels are lower in subjects with higher 24-hr urine output. This observation is consistent with a role for NGF in an active process (trafficking) involved in bladder filling. PMID:17266135
Oel, Carolin; Gerhards, Hartmut; Gehlen, Heidrun
Analysis of any effect of retrobulbar block during ocular surgery on heart rate variability and oculocardiac reflex. Prospective study. Horses (n = 16) undergoing eye enucleation due to chronic ophthalmologic diseases. Eye enucleation was performed under general anesthesia. The horses were randomly assigned to the first (inhalation anesthesia only, n = 10) or second group (inhalation and local retrobulbar anesthesia, n = 6). The retrobulbar block was performed using 12 mL of mepivacaine hydrochloride 2%. ECG data were taken by a Telemetric ECG before, during, and after surgery. Heart rate variability was analyzed in the time domain as mean heart rate, mean beat-to-beat interval duration, and standard deviation of continuous beat-to-beat intervals. The frequency domain analysis included the low- and high-frequency components of heart rate variability and the sympathovagal balance (low/high frequency). The low frequency represents mainly sympathetic influences on the heart, whereas high frequency is mediated by the parasympathetic tone. All horses without a retrobulbar block showed a significant decrease in the heart rate during traction on the globe and pressure on the orbital fat pad for homoestasis (P = 0.04). Simultaneously, high-frequency power, as an indicator of vagal stimulation, increased significantly. High-frequency and low-frequency power in the retrobulbar block group increased in five horses, and heart rate decreased in only one horse. Both were not significant within the group, but there was a significant difference between both groups relating to the incidence of heart rate decrease occurring at globe traction. Heart rate variability is a sensitive, non-invasive parameter to obtain sympathovagal stimulations during general anesthesia. The retrobulbar block can prevent heart rate decrease associated with initiation of the oculocardiac reflex. © 2013 American College of Veterinary Ophthalmologists.
Jo, Youn Yi; Choi, Eunkyeong
Background During transurethral resection of bladder tumors (TURB) under spinal anesthesia, electrical resection of the lateral wall mass may cause violent adductor contraction and possible inadvertent bladder perforation. Therefore, obturator nerve block (ONB) is mandatory after spinal anesthesia to avoid adductor muscle contraction. We compared the success rate and efficacy of an inguinal approach, to a pubic approach for ONB. Methods One hundred and two patients who required ONB undergoing TURB with spinal anesthesia were included in this study. After spinal anesthesia, ONB was performed with an inguinal approach (Group I, n = 51) or pubic approach (Group P, n = 51) using a nerve stimulator. In the pubic approach, a needle was inserted at a point 1.5 cm lateral and 1.5 cm inferior to the pubic tubercle. For the inguinal approach, a needle was inserted at the midpoint of the femoral artery and the inner margin of the adductor longus muscle 0.5 cm below the inguinal crease. If the adductor contracture had not occurred by the 3rd attempt, it was defined as a failed block. Puncture frequency, success rate, anatomical characteristics, and the presence of adductor muscle contraction during operation were evaluated. Results The success rate of ONB was higher in group I compared to group P (96.1% vs. 84.0%, P = 0.046) and the frequency of needle attempts was lower in group I than in group P (1.8 ± 0.9 vs. 1.3 ± 0.6, P = 0.01). Conclusions The inguinal approach for ONB appears to be technically easier and offers certain anatomical advantages when compared to the pubic approach. PMID:21927685
Comparison of continuous femoral nerve block (CFNB/SA) and continuous femoral nerve block with mini-dose spinal morphine (CFNB/SAMO) for postoperative analgesia after total knee arthroplasty (TKA): a randomized controlled study.
Sundarathiti, Petchara; Thammasakulsiri, Jadesadha; Supboon, Supawadee; Sakdanuwatwong, Supalak; Piangjai, Molruedee
Unsatisfactory analgesia for major knee surgery with femoral nerve block (FNB) alone was reported and the additional benefit of sciatic block to continuous femoral nerve block (CFNB) was not conclusive. The aim of the present study was to find the benefit of the additional mini-dose spinal morphine (0.035 mg) to CFNB for postoperative pain control and to compare their associated side effects after total knee arthroplasty (TKA). After written informed consent and with Institutional Ethics Committee approval, 68 American Society of Anesthesiologists (ASA) Physical Status I-III patients scheduled for elective unilateral TKA under spinal anesthesia (SA) were included in the present prospective, randomized controlled study. The patients were allocated into two groups. CFNB was placed in all patients by the inguinal paravascular approach with 20 ml of 0.25 % levobupivacaine. Group I (named CFNB/SA group), SA was administered with 2.8 ml levobupivacaine and Group II (named CFNB/SAMO group), SA with 2.8 ml levobupivacaine plus morphine 0.035 mg. At Post Anesthesia Care Unit (PACU), pain and other adverse effects were recorded. Pain was assessed by visual analog scale (VAS) 0-10. Tramadol 50 mg intravenous (IV) was given if the VAS > 4. In the ward, all patients were maintained by continuous femoral infusion of 0.125 % levobupivacaine rate 7 ml/hr and then reduced to 5 ml/hr if VAS ≤3. Patient's demographics data in each group were not different. At post-operative (PO) 12-24 h, the VAS scores were significantly lesser in the CFNB/SAMO group. Cumulative tramadol IV requirement for PO48h were also significantly lesser in the CFNB/SAMO group. Nausea, vomiting and numbness were significantly greater in the CFNB/SAMO group during early postoperative period (PO1-6 h). Though in some patients CFNB was inadequate, a mini-dose of intrathecal morphine (0.035 mg) in addition to CFNB was found to be effective with minimal side effects. Thai Clinical Trial Registry
Graf, B M; Martin, E
General anaesthesia and peripheral neuronal blockade are techniques which were introduced into clinical practice at the same time. Although general anaesthesia was accepted significantly faster due to effective new drugs and apparent ease of handling, neuronal blockade has recently gained great importance. The reasons are in particular newer aids such as industrially produced catheter sets, nerve stimulators and ultrasound guidance which have facilitated that these economical techniques can be used not only for intraoperative anaesthesia but also for perioperative analgesia without any major risks for the patients. In parallel to epidural anaesthesia a change of paradigms has recently taken place using catheter instead of single-shot techniques. This allows the loading dose of the local anaesthetics to be installed in a safe way, to reload the dose when intraoperatively required and to extend the analgesia perioperatively by this technique using lower concentrations of the same drugs or drug combinations. A great number of short, middle or long acting local anaesthetics are available to choose the right drug for any particular case. Short and middle acting drugs are characterised by a faster onset compared to long acting drugs, but toxic plasma levels are seen during long time application causing seizures or drowsiness or by using prilocaine methemoglobin. Therefore long acting local anaesthetics such as bupivacaine, ropivacaine or levobupivacaine are the first choice drugs for long time application via peripheral nerve catheters for perioperative anaesthesia and analgesia. By using low concentrations of these potent drugs even for a longer period of time, no toxic plasma levels are seen with the exception of artificial intravasal injections. Additives such as opioids and alpha 2-sympathomimetics are also used. While the use of opioids is controversial, alpha 2-sympathomimetics are able to accelerate the onset and to extend the duration of regional anaesthesia and
Marra, V; Debernardi, F; Frigerio, A; Menna, S; Musso, L; Di Virgilio, M R
CT-guided celiac plexus and splanchnic nerve neurolytic blocks are procedures for pain relief in patients with upper abdominal malignancies. In the last 20 years, the technique has been modified by the introduction of CT guidance providing improved precision and safety. We report our personal experience and provide suggestions for technique optimization. In 1991-1998 we performed 150 celiac plexus and/or splanchnic nerve neurolytic blocks with ethyl alcohol in 144 cancer patients; the procedure was repeated in 6 patients. In 69% of cases the patient had a pancreatic lesion. We prefer an anterior approach with very thin needles (22 Gauge). The sites of alcohol injection (celiac plexus, splanchnic nerves or both) are chosen after evaluation of anatomy by preliminary CT scans, or during the procedure, depending on alcohol (mixed with a contrast agent) spread. The mean duration of the procedure ranged 50 min (1991) to 22 min (1998). 48 hours after the block we obtained major pain relief in 79% of cases. After 15 days, 21% of patients had no pain (drugs: none), 29% had mild pain (therapy: non-steroid anti-inflammatory drugs), 32% had marked pain (therapy: non-steroid anti-inflammatory drugs and, occasionally, opioids), 18% had severe pain (only opioid therapy). Pain relief was more frequent in splanchnic nerve blocks. Our experience confirms that neurolytic celiac plexus and/or splanchnic nerve block is a good choice in the treatment of upper abdominal cancer pain. We would also like to add that: 1) celiac plexus block with CT guidance (with the needle tip positioned anterior to aorta) and splanchnic nerve block (with the needle tip positioned posterior to diaphragmatic crura) are no longer two separated techniques, but they can be chosen and combined according to patients needs. 2) All procedures can be performed with anterior approach, in supine position, with a single thin needle, allowing to reach the target without any complication, even after puncturing stomach
Campoy, Luis; Adami, Chiara
Locoregional anesthetic techniques may be a very useful tool for the anesthetic management of wallabies with injuries of the pelvic limbs and may help to prevent capture myopathies resulting from stress and systemic opioids' administration. This report describes the use of ultrasound-guided femoral and sciatic nerve blocks in Bennett's wallaby (Macropus rufogriseus) referred for orthopaedic surgery. Ultrasound-guided femoral and sciatic nerve blocks were attempted at the femoral triangle and proximal thigh level, respectively. Whilst the sciatic nerve could be easily visualised, the femoral nerve could not be readily identified. Only the sciatic nerve was therefore blocked with ropivacaine, and methadone was administered as rescue analgesic. The ultrasound images were stored and sent for external review. Anesthesia and recovery were uneventful and the wallaby was discharged two days postoperatively. At the time of writing, it is challenging to provide safe and effective analgesia to Macropods. Detailed knowledge of the anatomy of these species is at the basis of successful locoregional anesthesia. The development of novel analgesic techniques suitable for wallabies would represent an important step forward in this field and help the clinicians dealing with these species to improve their perianesthetic management. PMID:27803817
Mou, Zongxia; Triantis, Iasonas F; Woods, Virginia M; Toumazou, Christofer; Nikolic, Konstantin
The electrical behavior of the Xenopus laevis nerve fibers was studied when combined electrical (cuff electrodes) and optical (infrared laser, low power sub-5 mW) stimulations are applied. Assuming that the main effect of the laser irradiation on the nerve tissue is the localized temperature increase, this paper analyzes and gives new insights into the function of the combined thermoelectric stimulation on both excitation and blocking of the nerve action potentials (AP). The calculations involve a finite-element model (COMSOL) to represent the electrical properties of the nerve and cuff. Electric-field distribution along the nerve was computed for the given stimulation current profile and imported into a NEURON model, which was built to simulate the electrical behavior of myelinated nerve fiber under extracellular stimulation. The main result of this study of combined thermoelectric stimulation showed that local temperature increase, for the given electric field, can create a transient block of both the generation and propagation of the APs. Some preliminary experimental data in support of this conclusion are also shown.
Dziadzko, Mikhail A; Heritier, Fabrice
Extraoral mandibular nerve block (MNB) is used in oropharyngeal surgery for analgesia and anesthesia. Repeated or continuous MNB has been used successfully as treatment for uncontrollable pain, masseter spasticity, and airway assessment. The usual technique involves transcutaneous infrazygomatic access. However, in some specific settings, this approach is not always feasible. A continuous bilateral MNB with a suprazygomatic approach to the pterygomandibular space was used to resolve a case of refractory and painful trismus in a patient with tetraplegia. Analgesia was achieved and maintained by bilateral catheter placement to the pterygomandibular space and repeated injection of local anesthetic for 48 hours. The right-side catheter was accidentally withdrawn; the left-side catheter was maintained up to 72 hours. The efficiency of analgesia was not affected. This block provided effective analgesia within the first few hours after local anesthetic injection, helped to improve mouth opening, and resolved acute pain. Because kinesitherapy could be introduced, the patient was left on nonopioid analgesics. Continuous bilateral MNB through the suprazygomatic approach was used safely and efficiently. The suggested approach is quite unique, as is the clinical circumstance, and might be considered when the usual technique is challenging. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.
Medeiros Venancio, Antonio; da Silva-Alves, Kerly Shamyra; de Carvalho Pimentel, Hugo; Macêdo Lima, Matheus; Fraga de Santana, Michele; Batista da Silva, Givanildo; Marchioro, Murilo
The racemate linalool and its levogyrus enantiomer [(−)-LIN] are present in many essential oils and possess several pharmacological activities, such as antinociceptive and anti-inflammatory. In this work, the effects of essential oil obtained from the cultivation of the Ocimum basilicum L. (EOOb) derived from Germplasm Bank rich in (−)-LIN content in the excitability of peripheral nervous system were studied. We used rat sciatic nerve to investigate the EOOb and (−)-LIN effects on neuron excitability and the extracellular recording technique was used to register the compound action potential (CAP). EOOb and (−)-LIN blocked the CAP in a concentration-dependent way and these effects were reversible after washout. EOOb blocked positive amplitude of 1st and 2nd CAP components with IC50 of 0.38 ± 0.2 and 0.17 ± 0.0 mg/mL, respectively. For (−)-LIN, these values were 0.23 ± 0.0 and 0.13 ± 0.0 mg/mL. Both components reduced the conduction velocity of CAP and the 2nd component seems to be more affected than the 1st component. In conclusion EOOb and (−)-LIN inhibited the excitability of peripheral nervous system in a similar way and potency, revealing that the effects of EOOb on excitability are due to the presence of (−)-LIN in the essential oil. PMID:27446227
Ezoddini Ardakani, Fatemeh; Bahrololoumi, Zahra; Zangouie Booshehri, Maryam; Navab Azam, Alireza; Ayatollahi, Fatemeh
Background and aims Inferior alveolar nerve block injection is one of the common intra oral anesthetic techniques, with a failure rate of 15-20%. The aim of this study was to evaluate the position of the lingula as an index for this injection. Materials and methods Thirty eight panoramic radiographs of 7–11 year old patients were analyzed and the distance between the lingula index and occlusal plane was measured. Then, lower alveolar nerve block injection was performed on 88 children. Finally, a visual analogue scale was used to measure the rate of pain in the patients. Results This distance increased with age and in children younger than nine years is −0.45 mm on the right side and −0.95 mm on the left side. This distance in children older than 9 years is −0.23 mm on the right side and 0.47 mm on the left side. The success rates of inferior alveolar nerve block injection based on lingual index were 49% on the right side and 53.8% on the left side. Conclusion As the lingual index has various positions and its distance from the occlusal plane increases with age, it is not an appropriate landmark for inferior alveolar nerve block injection. PMID:22991596
Zain, Muhammad; Rehman Khattak, Shakeel Ur; Sikandar, Huma; Shah, Shafqat Ali; Fayyaz
To evaluate success of pulpal anaesthesia of mandibular 1st molar by using 4% articaine in buccal infiltration versus 2% lidocaine in inferior alveolar nerve block. Randomized control trial. Department of Operative Dentistry, Sardar Begum Dental College, Gandhara University, Peshawar, from March to August 2014. One hundred and fifty-six emergency patients, who had 1st molar diagnosed with irreversible pulpitis, participated in the study. Subjects were divided into two groups by random allocation. One group received 4% articaine buccal infiltration and the other group received inferior alveolar nerve block of 2% lidocaine. Subjects’self-reported pain response was recorded on Heft Parker Visual Analogue Scale after local anaesthetic administration during access cavity preparation and pulp extirpation. Mean age of subjects was 31.46 ±10.994 years. The success rate of 4% buccal infiltration was 76.9%; whereas the success rate of 2% lidocaine inferior alveolar nerve block was 62.8%. There was no statistically significant difference between the two groups. 4% articaine buccal infiltration can be considered a viable alternative to 2% lidocaine inferior alveolar nerve block in securing successful pulpal anaesthesia for endodontic therapy.
Vallence, Ann-Maree; Hammond, Geoffrey R; Reilly, Karen T
Human motor cortex is capable of rapid and long-lasting reorganization, evident globally, as shifts in body part representations, and at the level of individual muscles as changes in corticospinal excitability. Representational shifts provide an overview of how various body parts reorganize relative to each other but do not tell us whether all muscles in a given body part reorganize in the same manner and to the same extent. Transcranial magnetic stimulation (TMS) provides information about individual muscles and can therefore inform us about the uniformity of plastic changes within a body part. We used TMS to investigate changes in corticospinal excitability of forearm flexors and extensors after inflation of a tourniquet around the wrist. Motor evoked potential (MEP) amplitudes and input/output (I/O) curves were obtained from wrist flexors and extensors simultaneously before and during block. TMS was delivered to the optimal site for eliciting MEPs in flexors in experiment 1, extensors in experiment 2, and both flexors and extensors in experiment 3. In all experiments flexor MEP amplitude increased during block while extensor MEP amplitude showed no systematic change, and the slope of flexor but not extensor I/O curves increased. Flexor H-reflex amplitude normalized to maximal M wave showed negligible changes during block, suggesting that the increase in corticospinal excitability in the flexors cannot be completely explained by increased excitability at the spinal cord level. These findings show that forearm flexors and extensors differ in their potential for plastic changes, highlight the importance of investigating how experimentally induced plasticity affects anatomically close, but functionally distinct, muscle groups, and suggest that rehabilitation interventions aiming to alter cortical organization should consider the differential sensitivity of various muscle groups to plasticity processes.
Williams, Brian A.; Bottegal, Matthew T.; Kentor, Michael L.; Irrgang, James J.; Williams, John P.
Background and objectives Continuous perineural femoral analgesia has been reported to reduce numeric rating pain scores (NRS, scale zero to 10) after anterior cruciate ligament reconstruction (ACLR). In the current study, we determined rebound pain scores in autograft ACLR outpatients after nerve block analgesia resolved. Methods After standardized spinal anesthesia and perioperative multimodal analgesia, patients received a femoral perineural catheter and 50 hours of saline or levobupivacaine. All patients received levobupivacaine (30 mL of 0.25% as a bolus) before the infusion. Patients completed a pain diary for 6 days, indicating serial NRS scores and perceptions of when nerve block analgesia resolved. Block duration and rebound pain scores were computed. Results Data from 84 participants’ pain diaries were analyzed. Patients receiving saline infusion reported mean nerve block duration of 37 hours, versus 59 hours for patients receiving the levobupivacaine infusion (P<0.001). Mean Rebound Pain Scores increased by 2.0 (95% CI: 1.6, 2.4). Based on the computations used to derive block duration and rebound pain scores, each hour of additional block duration was predictive of a 0.03 unit reduction in rebound pain scores. Conclusions In an anesthesia care protocol consisting of spinal anesthesia and multimodal analgesia during and after autograft ACL reconstruction, approximately 33 hours of additional nerve block duration were required to reduce rebound pain scores by one unit. Further study is required to determine rebound pain score differences when other local anesthetics and anesthetic/analgesic plans are being used, and when other surgeries are being performed. PMID:17543812
Yannas, I V; Tzeranis, D; So, P T
We review the details of preparation and of the recently elucidated mechanism of biological (regenerative) activity of a collagen scaffold (dermis regeneration template, DRT) that has induced regeneration of skin and peripheral nerves (PN) in a variety of animal models and in the clinic. DRT is a 3D protein network with optimized pore size in the range 20-125 µm, degradation half-life 14 ± 7 d and ligand densities that exceed 200 µM α1β1 or α2β1 ligands. The pore has been optimized to allow migration of contractile cells (myofibroblasts, MFB) into the scaffold and to provide sufficient specific surface for cell-scaffold interaction; the degradation half-life provides the required time window for satisfactory binding interaction of MFB with the scaffold surface; and the ligand density supplies the appropriate ligands for specific binding of MFB on the scaffold surface. A dramatic change in MFB phenotype takes place following MFB-scaffold binding which has been shown to result in blocking of wound contraction. In both skin wounds and PN wounds the evidence has shown clearly that contraction blocking by DRT is followed by induction of regeneration of nearly perfect organs. The biologically active structure of DRT is required for contraction blocking; well-matched collagen scaffold controls of DRT, with structures that varied from that of DRT, have failed to induce regeneration. Careful processing of collagen scaffolds is required for adequate biological activity of the scaffold surface. The newly understood mechanism provides a relatively complete paradigm of regenerative medicine that can be used to prepare scaffolds that may induce regeneration of other organs in future studies.
Booth, Lindsea C.; May, Clive N.; Yao, Song T.
Renal nerves contain afferent, sensory and efferent, sympathetic nerve fibers. In heart failure (HF) there is an increase in renal sympathetic nerve activity (RSNA), which can lead to renal vasoconstriction, increased renin release and sodium retention. These changes are thought to contribute to renal dysfunction, which is predictive of poor outcome in patients with HF. In contrast, the role of the renal afferent nerves remains largely unexplored in HF. This is somewhat surprising as there are multiple triggers in HF that have the potential to increase afferent nerve activity, including increased venous pressure and reduced kidney perfusion. Some of the few studies investigating renal afferents in HF have suggested that at least the sympatho-inhibitory reno-renal reflex is blunted. In experimentally induced HF, renal denervation, both surgical and catheter-based, has been associated with some improvements in renal and cardiac function. It remains unknown whether the effects are due to removal of the efferent renal nerve fibers or afferent renal nerve fibers, or a combination of both. Here, we review the effects of HF on renal efferent and afferent nerve function and critically assess the latest evidence supporting renal denervation as a potential treatment in HF. PMID:26483699
Booth, Lindsea C; May, Clive N; Yao, Song T
Renal nerves contain afferent, sensory and efferent, sympathetic nerve fibers. In heart failure (HF) there is an increase in renal sympathetic nerve activity (RSNA), which can lead to renal vasoconstriction, increased renin release and sodium retention. These changes are thought to contribute to renal dysfunction, which is predictive of poor outcome in patients with HF. In contrast, the role of the renal afferent nerves remains largely unexplored in HF. This is somewhat surprising as there are multiple triggers in HF that have the potential to increase afferent nerve activity, including increased venous pressure and reduced kidney perfusion. Some of the few studies investigating renal afferents in HF have suggested that at least the sympatho-inhibitory reno-renal reflex is blunted. In experimentally induced HF, renal denervation, both surgical and catheter-based, has been associated with some improvements in renal and cardiac function. It remains unknown whether the effects are due to removal of the efferent renal nerve fibers or afferent renal nerve fibers, or a combination of both. Here, we review the effects of HF on renal efferent and afferent nerve function and critically assess the latest evidence supporting renal denervation as a potential treatment in HF.
Exposure to N-ethylmaleimide (NEM), a reagent that binds covalently to protein sulfhydryl groups, results in a specific reduction in sodium conductance in crayfish axons. Resting potential, the delayed rise in potassium conductance, and the selectivity of the sodium channel are unaffected. Sodium currents are only slightly increased by hyperpolarizing prepulses of up to 50 ms duration, but can be restored to about 70% of their value before treatment if this duration is increased to 300-800 ms. The time to peak sodium current and the time constant of decay of sodium tail currents are unaffected by NEM, suggesting that the sodium activation system remains unaltered. Kinetic studies suggest that NEM reacts with a "slow" sodium inactivation system that is present in normal axons and that may be seen after depolarization produced by lowered the holding potential or increasing the external potassium concentration. NEM also perturbs the fast h inactivation system, and in a potential-dependent manner. At small depolarizations tauh is decreased, while at strong depolarizations it is increased over control values. Experiments with structural analogs of NEM suggest that sulfhydryl block is involved, but do not rule out an action similar to that of local anesthetics, p- Chloromercuriphenylsulfonic acid (PCMBS), another reagent with high specificity for SH groups, also blocks sodium currents, but restoration with prolonged hyperpolarizations is not possible. PMID:839196
Song, Jae-Hwang; Kang, Chan; Hwang, Deuk-Soo; Hwang, Jung-Mo; Shin, Byung-Kon
The analgesic effects of preoperative ultrasound-guided nerve blocks wear off after about 12 hours, leaving some patients in substantial pain. Transdermal fentanyl concentrations peak at 12 to 24 hours after application and maintain this concentration for approximately 72 hours. We sought to determine whether combining the use of a transdermal fentanyl patch with either a sciatic or femoral-sciatic nerve block would improve pain control in patients undergoing foot and/or ankle surgery. Consecutive patients in the no-patch control group (n = 104) were enrolled from July 2011 to October 2011, and those in the treatment group (n = 232) were enrolled from November 2011 to May 2012 and received a transdermal patch (4.125 mg/7.5 cm(2) releasing 25 μg of fentanyl per hour) applied to their chest postoperatively. Pain was assessed using a visual analog scale at 6, 12, 24, and 48 hours after surgery. The primary outcome measure was the number of requests for additional postoperative pain medication. Additional postoperative analgesia was requested by 49 of the 104 control patients (47.1%) and 63 of the 232 treated patients (27.1%; p = .002). The mean pain scores were also lower in the treatment group, with a statistically significant difference (p < .05) at 12, 24, and 48 hours. Thus, patients receiving a fentanyl patch combined with an ultrasound-guided nerve block required less supplemental analgesia to maintain adequate pain control than did those receiving a nerve block alone. In conclusion, a fentanyl patch is a useful adjunct to an ultrasound-guided nerve block in foot and ankle surgery. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.
Zhu, Shu; Ge, Jun; Liu, Zhongyang; Liu, Liang; Jing, Da; Ran, Mingzi; Wang, Meng; Huang, Liangliang; Yang, Yafeng; Huang, Jinghui; Luo, Zhuojing
Circadian rhythm (CR) plays a critical role in the treatment of several diseases. However, the role of CR in the treatment of peripheral nerve defects has not been studied. It is also known that the pulsed electromagnetic fields (PEMF) can provide a beneficial microenvironment to quicken the process of nerve regeneration and to enhance the quality of reconstruction. In this study, we evaluate the impact of CR on the promoting effect of PEMF on peripheral nerve regeneration in rats. We used the self-made “collagen-chitosan” nerve conduits to bridge the 15-mm nerve gaps in Sprague-Dawley rats. Our results show that PEMF stimulation at daytime (DPEMF) has most effective outcome on nerve regeneration and rats with DPEMF treatment achieve quickly functional recovery after 12 weeks. These findings indicate that CR is an important factor that determines the promoting effect of PEMF on peripheral nerve regeneration. PEMF exposure in the daytime enhances the functional recovery of rats. Our study provides a helpful guideline for the effective use of PEMF mediations experimentally and clinically. PMID:28360885
Howden, Erin J; Lawley, Justin S; Esler, Murray; Levine, Benjamin D
Chronic kidney disease (CKD), is characterized by a progressive loss of renal function and increase in cardiovascular risk. In this review paper, we discuss the pathophysiology of increased sympathetic nerve activity in CKD patients and raise the possibility of endurance exercise being an effective countermeasure to address this problem. We specifically focus on the potential role of endurance training in altering renal sympathetic nerve activity as increased renal sympathetic nerve activity negatively impacts kidney function as well indirectly effects multiple other systems and organs. Recent technological advances in device based therapy have highlighted the detrimental effect of elevated renal sympathetic nerve activity in CKD patients, with kidney function and blood pressure being improved post renal artery nerve denervation in selected patients. These developments provide optimism for the development of alternative and/or complementary strategies to lower renal sympathetic nerve activity. However, appropriately designed studies are required to confirm preliminary observations, as the widespread use of the renal denervation approach to lower sympathetic activity presently has limited feasibility. Endurance training may be one alternative strategy to reduce renal sympathetic nerve activity. Here we review the role of endurance training as a potential alternative or adjunctive to current therapy in CKD patients. We also provide recommendations for future research to assist in establishing an evidence base for the use of endurance training to lower renal sympathetic activity in CKD patients.
Spinelli, Giuseppe; Rocchetta, Davide; Carnevali, Giulia; Valente, Domenico; Conti, Marco
Background: Orbital blowout fractures can be managed by several surgical specialties including plastic and maxillofacial surgery, otolaryngology, and ophthalmology. Recommendations for surgical fracture repair depend on a combination of clinical and imaging studies to evaluate muscle/nerve entrapment and periorbital tissue herniation. Methods: The aim of this study was to verify the applicability of regional anesthesia when repairing orbital floor fractures. A retrospective chart review was performed for isolated orbital floor fractures treated at the Department of Maxillofacial Surgery in Florence between May 2011 and July 2012. The study included 135 patients who met the inclusion criteria: 96 subjects were male (71%) and 39 were female (29%). The mean age was 45.3 years, ranging from 16 to 77 years. Results: The results revealed that isolated anterior orbital floor fractures can be safely repaired under regional and local anesthesia. Regional and local anesthesia should be combined with intravenous sedation when the fracture involves the posterior floor. The surgical outcome was comparable to the outcome achieved under general anesthesia. There was a lower rate of surgical revisions due to concealed malposition or entrapment of the inferior rectus muscle (19% vs 22%). However, this result was not statistically significant (P > 0.05). Conclusions: There are several advantages to surgically repairing isolated orbital floor fractures under regional and local anesthesia that include the following: surgeons can check the surgical outcome (enophthalmos and extrinsic ocular muscles function) intraoperatively, thereby reducing the reoperation rate; patient discomfort due to general anesthesia is eliminated; and the hospital stay is reduced, thus decreasing overall healthcare costs. PMID:25289294
Okmen, Korgun; Dagistan, Yasar; Dagistan, Emine; Kaplan, Necati; Cancan, Emre
We aimed to evaluate six months of results following repeated GON blocks. We evaluated the results from GON block performed on 60 patients. Briefly, we applied a standard 2 mL of 0.5% Bupivacaine GON blockage once a week for 4 weeks. We recorded the Visual Analog Scale (VAS) scores, the number of migraine attacks and the Migraine Disability Assessment Questionnaire (MIDAS) scores. The study subjects were not allowed to use medication for prophylaxis, and Ibuprofen (400 mg, 1200 mg at maximum) was prescribed for any migraine attacks. The initial mean number of attacks per month before starting treatment was 8.33+2.31. After treatment, the initial MIDAS mean was found to be 2.82 per month; this declined to 1.47 in 3rd, and was 1.50 in the 6th month. The individual month values were found to be significant, and were listed respectively as, 1st month: 3.95+2.52, 2nd month: 3.23+1.82, 3rd month: 2.60+1.90, 4th month: 2.68+2.10, 5th month: 2.58+1.90 and 6th month: 2.58+1.90. The mean VAS scores were recorded as follows for each month: 6.28±1.24, 3.13±0.97, 2.55±1.19, 2.35±1.26, 2.38±1.20 and 2.48±1.30, respectively. This difference was noted to be statistically significant. No difference regarding the efficacy of the treatment was determined when the results were compared across age groups. We assume that GON blockage with 2 mL of 0.5% Bupivacaine can be a supportive treatment in migraine treatment, with no serious adverse effects reported. Copyright © 2016 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.
Methathrathip, D; Apinhasmit, W; Chompoopong, S; Lertsirithong, A; Ariyawatkul, T; Sangvichien, S
This study aims to investigate the anatomy of the greater palatine foramen (GPF), greater palatine canal (GPC) and pterygopalatine fossa (PPF) with special reference to the blockage of the maxillary nerve. A correlation between the length of GPC and PPF and the heights of the orbit and the maxilla was also studied using simple linear regression analysis. The morphology of the GPF, GPC and PPF as well as heights of the orbit and the maxilla were assessed in 105 Thai skulls. The thickness of the mucosa over the GPF was also measured from the dissection of 55 cadavers. The results showed that most GPF appeared as an oval foramen located at the palatal aspect of the upper third molar. The GPF was 16.2+/-1.3 mm lateral to the median sagittal plane of the hard palate, 2.1+/-1.3 mm anterior to the posterior border of the hard palate and 5.1+/-1.3 mm from the greatest concavity of the distolateral margin of the hard palate. The mean length of GPC and PPF was 29.7+/-4.2 mm. The mean angles of the GPC in relation to the hard palate and the vertical plane were 57.9+/-5.8 degrees and 6.7+/-5.2 degrees , respectively. In attempting to insert a needle to reach the foramen rotundum through the GPF, 31.7% passed into the orbit while 8.7% passed into the brain. The mean thickness of the mucosa over GPF was 6.7+/-2.3 mm. Two models for estimating the depth of needle injection in maxillary nerve block have been developed as follows: Length of GPC and PPF=19.038+0.314 (orbital height) and length of GPC and PPF=21.204+0.187 (maxillary height). The calculated length combined with the mucosal thickness was the estimated depth of needle injection. In conclusion, our results concerning the GPF, GPC and PPF will provide the useful reference for clinicians to anesthetize the maxillary nerve with a greater degree of success.
Iwase, Satoshi; Nishimura, Naoki; Mano, Tadaaki
Syncope is defined as a transient loss of consciousness and postural tone, characterized by rapid onset, short duration, and spontaneous recovery, and the process of syncope progression is here described with two types of sympathetic change. Simultaneous recordings of microneurographically-recorded muscle sympathetic nerve activity (MSNA) and continuous and noninvasive blood pressure measurement has disclosed what is going on during the course of syncope progression. For vasovagal or neurally mediated syncope, three stages are identified in the course of syncope onset, oscillation, imbalance, and catastrophe phases. Vasovagal syncope is characterized by sympathoexcitation, followed by vagal overcoming via the Bezold-Jarisch reflex. Orthostatic syncope is caused by response failure or a lack of sympathetic nerve activity to the orthostatic challenge, followed by fluid shift and subsequent low cerebral perfusion. Four causes are considered for the compensatory failure that triggers orthostatic syncope: hypovolemia, increased pooling in the lower body, failure to activate sympathetic activity, and failure of vasoconstriction against sympathetic vasoconstrictive stimulation. Many pathophysiological conditions have been described from the perspectives of (1) exaggerated sympathoexcitation and (2) failure to activate the sympathetic nerve. We conclude that the sympathetic nervous system can control cardiovascular function, and its failure results in syncope; however, responses of the system obtained by microneurographically-recorded MSNA would determine the pathophysiology of the onset and progression of syncope, explaining the treatment effect that could be achieved by the analysis of this mechanism. PMID:25309444
Mao, Qingxiang; Yuan, Jingjing; Xiong, Ming; Wu, Shaogen; Chen, Liyong; Bekker, Alex; Yang, Tiande
Peripheral nerve injury-caused hyperexcitability and abnormal ectopic discharges in the primary sensory neurons of dorsal root ganglion (DRG) play a key role in neuropathic pain development and maintenance. The two-pore domain background potassium (K2P) channels have been identified as key determinants of the resting membrane potential and neuronal excitability. However, whether K2P channels contribute to neuropathic pain is still elusive. We reported here that K2P1.1, the first identified mammalian K2P channel, was highly expressed in mouse DRG and distributed in small-, medium-, and large-sized DRG neurons. Unilateral lumbar (L) 4 spinal nerve ligation led to a significant and time-dependent reduction of K2P1.1 mRNA and protein in the ipsilateral L4 DRG, but not in the contralateral L4 or ipsilateral L3 DRG. Rescuing this reduction through microinjection of adeno-associated virus-DJ expressing full-length K2P1.1 mRNA into the ipsilateral L4 DRG blocked spinal nerve ligation-induced mechanical, thermal, and cold pain hypersensitivities during the development and maintenance periods. This DRG viral microinjection did not affect acute pain and locomotor function. Our findings suggest that K2P1.1 participates in neuropathic pain development and maintenance and may be a potential target in the management of this disorder. PMID:28326939
de Lartigue, Guillaume
This review highlights evidence for a role of the vagus nerve in the development of obesity and how targeting the vagus nerve with neuromodulation or pharmacology can be used as a therapeutic treatment of obesity. The vagus nerve innervating the gut plays an important role in controlling metabolism. It communicates peripheral information about the volume and type of nutrients between the gut and the brain. Depending on the nutritional status, vagal afferent neurons express two different neurochemical phenotypes that can inhibit or stimulate food intake. Chronic ingestion of calorie-rich diets reduces sensitivity of vagal afferent neurons to peripheral signals and their constitutive expression of orexigenic receptors and neuropeptides. This disruption of vagal afferent signalling is sufficient to drive hyperphagia and obesity. Furthermore neuromodulation of the vagus nerve can be used in the treatment of obesity. Although the mechanisms are poorly understood, vagal nerve stimulation prevents weight gain in response to a high-fat diet. In small clinical studies, in patients with depression or epilepsy, vagal nerve stimulation has been demonstrated to promote weight loss. Vagal blockade, which inhibits the vagus nerve, results in significant weight loss. Vagal blockade is proposed to inhibit aberrant orexigenic signals arising in obesity as a putative mechanism of vagal blockade-induced weight loss. Approaches and molecular targets to develop future pharmacotherapy targeted to the vagus nerve for the treatment of obesity are proposed. In conclusion there is strong evidence that the vagus nerve is involved in the development of obesity and it is proving to be an attractive target for the treatment of obesity.
Campoy, Luis; Martin-Flores, Manuel; Ludders, John W; Erb, Hollis N; Gleed, Robin D
To evaluate the efficacy of combined femoral and sciatic nerve blocks as an alternative to epidural anesthesia and analgesia in dogs undergoing stifle surgery under general anesthesia. Prospective, blinded, randomized, clinical comparison. Twenty dogs weighing 37 ± 11 (mean ± SD) kg, aged 3 (1-8) [median (minimum-maximum)] years undergoing elective unilateral tibial-plateau leveling osteotomy. Dogs were assigned randomly to receive either epidural anesthesia (bupivacaine 0.5%, 0.5 mg kg(-1) + morphine 0.1%, 0.1 mg kg(-1), in 0.2 mL kg(-1); EPID) or femoral and sciatic nerve blocks (Bupivacaine 0.5%, 0.1 mL kg(-1), was administered at each site; F + S) guided by electrolocation. All patients received a standard general anesthesia technique. Pain and sedation were scored (on scales of 0-10 and 0-3, respectively) pre-operatively, at extubation, and at 1, 4 and then every 4 hours thereafter up to 24 hours. Postoperatively, hydromorphone was administered to any patient with a pain score of >5 or whenever the blinded caregiver determined that more hydromorphone was necessary. Intraoperative heart rate (HR), mean arterial pressure (MAP), end tidal isoflurane (FE'ISO), body temperature, post-operative pain scores, time to first hydromorphone dose after surgery, time to first feeding, time to first drinking, time to first urination, time to first ambulation (walk on a lead) and cumulative dose of hydromorphone were recorded. Intra-operatively, FE'ISO and MAP were significantly lower in the EPID group (p = 0.05 and p = 0.04, respectively). Postoperatively, the cumulative hydromorphone consumption (p = 0.04) and the incidence of urinary retention (p = 0.03) were higher in the EPID group. F + S is a practical alternative to EPID that produces less urine retention and reduces opioid consumption in the 24 hours after surgery. EPID might be associated with a lower isoflurane requirement and lower systemic blood pressure. © 2011 The Authors. Veterinary Anaesthesia and Analgesia
Lu, Yuechun; Sun, Jian; Zhuang, Xinqi; Lv, Guoyi; Li, Yize; Wang, Haiyun; Wang, Guolin
Research suggests that the addition of dexmedetomidine to local anesthetics can prolong peripheral nerve blocks; however, it is not known whether dexmedetomidine can reduce the quantity of local anesthetic needed. We hypothesized that adding dexmedetomidine as an adjuvant to an obturator nerve block could reduce the median effective concentration of lidocaine. In this double-blinded randomized trial, 60 patients scheduled for elective transurethral resection of bladder tumors on the lateral wall were randomly divided into two groups: the control group (C group, n = 30) and the dexmedetomidine group (D group, n = 30). Two main branches of the obturator nerve (i.e., anterior and posterior) were identified using neural stimulation at the inguinal level, with only lidocaine used for the C group and 1 μg/kg dexmedetomidine combined with lidocaine used for the D group. The median effective concentration was determined by an up-and-down sequential trial. The ratio of two consecutive concentrations was 1.2. The median effective concentration (95% confidence interval) of lidocaine was 0.57% (0.54%-0.62%) in the C group and 0.29% (0.28%-0.38%) in the D group. The median effective concentration of lidocaine was significantly lower in the D group than in the C group (p < 0.05). These results indicate that dexmedetomidine (1 μg/kg) in combination with lidocaine for obturator nerve block decreases the median effective concentration of lidocaine. ClinicalTrials.gov NCT02066727.
Brummett, Chad M.; Norat, Mary A.; Palmisano, John M.; Lydic, Ralph
Background The present study was designed to test the hypothesis that high-dose dexmedetomidine added to local anesthetic would increase the duration of sensory and motor blockade in a rat model of sciatic nerve blockade without causing nerve damage. Methods Thirty-one adult Sprague Dawley rats received bilateral sciatic nerve blocks with either 0.2 ml of 0.5% bupivacaine and 0.5% bupivacaine plus 0.005% dexmedetomidine in the contralateral leg, or 0.2 ml of 0.005% dexmedetomidine and normal saline in the contralateral leg. Sensory and motor function were assessed by a blinded investigator every 30 minutes until the return of normal sensory and motor function. Sciatic nerves were harvested at either 24 hours or 14 days after injection and analyzed for perineural inflammation and nerve damage. Results High-dose dexmedetomidine added to bupivacaine significantly enhanced the duration of sensory and motor blockade. Dexmedetomidine alone did not cause significant motor or sensory block. All of the nerves analyzed had normal axons and myelin at 24 hours and 14 days. Bupivacaine plus dexmedetomidine showed less perineural inflammation at 24 hours than the bupivacaine group when compared with the saline control. Conclusion The finding that high-dose dexmedetomidine can safely improve the duration of bupivacaine-induced antinociception following sciatic nerve blockade in rats is an essential first step encouraging future studies in humans. The dose of dexmedetomidine used in this study may exceed the sedative safety threshold in humans and could cause prolonged motor blockade, therefore future work with clinically relevant doses is necessary. PMID:18719449
Tamhankar, Madhura A; Volpe, Nicholas J
This article will discuss the management of isolated, acute cranial nerve 3,4 and 6 palsies with special focus on the role of neuroimaging in older adults based on recently published data. Acute cranial nerve palsies affecting the third, fourth or sixth cranial nerves in isolation or in combination with other neurological signs and symptoms can be due to a variety of causes such as ischemia, inflammation, infection and compression of the ocular motor nerves. Although neuroimaging is generally recommended in all individuals presenting with ocular motor nerve palsies that occur in association with other neurological signs and symptoms, the indications for neuroimaging in older individuals (age > 50 years) who present with acute isolated ocular motor nerve palsies are less clear and controversial. Past and recent studies have attempted to address this question. A recent prospective study found that overall 16.5% of adult patients presenting with acute ocular motor mononeuropathy had structural lesions on MRI scan and 4.6% with fourth and sixth nerve palsies and no risk factors were found to have positive MRI scans. On the basis of recently published data, we recommend contrast-enhanced MRI for all patients presenting with acute, isolated ocular motor mononeuropathies irrespective of age. Studies have clearly shown a small but significant prevalence of important findings in this group of patients thus favoring neuroimaging at the time of diagnosis.
Hendler, N; Bergson, C; Morrison, C
This study followed 120 chronic pain patients referred to a multidisciplinary pain center. The referral diagnosis for many patients, such as "chronic pain," "psychogenic pain," or "lumbar strain," was frequently found to be incomplete or inaccurate (40%) following a multidisciplinary evaluation that used appropriate diagnostic studies, including magnetic resonance imaging, computed tomography, nerve blocks, and qualitative flowmeter. Significant abnormalities were discovered in 76% of the diagnostic tests. An organic origin for pain was found in 98% of these patients. The patients were discharged with objective verification of diagnoses including facet disease, nerve entrapment, temporomandibular joint disease, thoracic outlet syndrome, and herniated discs.
Gaudreault, François; Drolet, Pierre; Fallaha, Michel; Varin, France
Because of its slow systemic absorption and flip-flop kinetics, ropivacaine's pharmacokinetics after a peripheral nerve block has never been thoroughly characterized. The purpose