Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of upper and lower limb nerve blocks.

BACKGROUND: Inconsistent nomenclature and anatomical descriptions of regional anesthetic techniques hinder scientific communication and engender confusion; this in turn has implications for research, education and clinical implementation of regional anesthesia. Having produced standardized nomenclature for abdominal wall, paraspinal and chest wall regional anesthetic techniques, we aimed to similarly do so for upper and lower limb peripheral nerve blocks. METHODS: We performed a three-round Delphi international consensus study to generate standardized names and anatomical descriptions of upper and lower limb regional anesthetic techniques. A long list of names and anatomical description of blocks of upper and lower extremities was produced by the members of the steering committee. Subsequently, two rounds of anonymized voting and commenting were followed by a third virtual round table to secure consensus for items that remained outstanding after the first and second rounds. As with previous methodology, strong consensus was defined as ≥75% agreement and weak consensus as 50%-74% agreement. RESULTS: A total of 94, 91 and 65 collaborators participated in the first, second and third rounds, respectively. We achieved strong consensus for 38 names and 33 anatomical descriptions, and weak consensus for five anatomical descriptions. We agreed on a template for naming peripheral nerve blocks based on the name of the nerve and the anatomical location of the blockade and identified several areas for future research. CONCLUSIONS: We achieved consensus on nomenclature and anatomical descriptions of regional anesthetic techniques for upper and lower limb nerve blocks, and recommend using this framework in clinical and academic practice. This should improve research, teaching and learning of regional anesthesia to eventually improve patient care.

Continuous bilateral subomohyoid suprascapular nerve blocks for postoperative analgesia for bilateral rotator cuff repair: a case report.

PURPOSE: Blocking the suprascapular nerve under the inferior belly of the omohyoid muscle is a novel regional anesthesia technique that has been proposed for shoulder analgesia. We describe the use of and our experience with bilateral indwelling suprascapular catheters for pain management via continuous infusions in a patient undergoing bilateral shoulder surgery. CLINICAL FEATURES: Bilateral subomohyoid suprascapular catheters were inserted prior to surgery for postoperative analgesia in a patient undergoing bilateral rotator cuff tear repair. The catheters were placed 0.5-1 cm beyond the needle tip, and low local anesthetic infusion rates (ropivacaine 0.2% at 5 mL·hr-1 on each side) were used. CONCLUSIONS: Judicious use of preoperatively placed bilateral suprascapular catheters added to a comprehensive multimodal analgesic regimen provided excellent analgesia without respiratory compromise throughout the perioperative course.

RéSUMé: OBJECTIF: Une nouvelle technique d'anesthésie régionale proposée pour l'analgésie de l'épaule consiste à bloquer le nerf suprascapulaire sous la partie inférieure du muscle omohyoïdien. Nous décrivons l'utilisation et notre expérience avec des cathéters suprascapulaires bilatéraux pour la prise en charge de la douleur par l'intermédiaire de perfusions continues chez un patient subissant une chirurgie bilatérale des épaules. ÉLéMENTS CLINIQUES: Des cathéters suprascapulaires sous-omohyoïdiens bilatéraux ont été insérés avant la chirurgie pour l'analgésie postopératoire d'un patient subissant une réparation bilatérale de rupture de la coiffe des rotateurs. Les cathéters ont été positionnés 0,5-1 cm au-delà de l'extrémité de l'aiguille, et de faibles quantités d'anesthésique local (ropivacaine 0,2 % à 5 mL·h−1 de chaque côté) ont été utilisées. CONCLUSION: L'utilisation judicieuse de cathéters suprascapulaires bilatéraux installés en période préopératoire, ajoutée à un régime analgésique multimodal exhaustif, a procuré une excellente analgésie sans atteinte respiratoire tout au long de la période périopératoire.

A novel approach of using brachial plexus blockade as an experimental model for diagnosis of intraoperative nerve dysfunction with somatosensory evoked potentials: a blinded proof-of-concept study.

PURPOSE: Intraoperative nerve dysfunction has been difficult to investigate because of its rarity and unpredictable occurrence. The diagnostic test attributes of nerve function monitors have not been clearly defined. This proof-of-concept study aimed to assess the feasibility of using brachial plexus blockade (BPB) in awake patients as an experimental model for nerve dysfunction to characterize the diagnostic test attributes of somatosensory evoked potentials (SSEPs). METHODS: We obtained baseline SSEPs and neurologic function in patients and subsequently placed BPBs (experimental model) to generate progressive states of nerve dysfunction. We monitored SSEP changes (index test) and neurologic symptoms (reference standard) simultaneously during the onset of BPB to determine the temporal relationships and diagnostic test attributes of SSEPs. RESULTS: Brachial plexus blockade produced differential motor and sensory dysfunction that allowed simultaneous clinical and neurophysiologic assessment. One hundred and fifty-seven pairs of multiple data points from 14 patients were included for final analysis. The onset of abnormal SSEP signals almost always preceded the onset of neurologic symptoms. The sensitivities and specificities of SSEP to detect the impairment of power (motor rating score ≤ 4/5), cold sensation, and two-point discrimination were 100% and 67%, 99% and 55%, and 100% and 46%, respectively. CONCLUSION: This study found that BPB can produce sufficient differential nerve dysfunction to allow adequate evaluation of the diagnostic test attributes of SSEPs as a nerve monitor. The results of this study may stimulate further work on refining intraoperative nerve dysfunction models and diagnostic nerve function monitors. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT03409536); registered 24 January 2018.

RéSUMé: OBJECTIF: La dysfonction nerveuse peropératoire est difficile à étudier en raison de sa rareté et de son imprévisibilité. Les attributs d'un test diagnostique des moniteurs de la fonction nerveuse n'ont pas été clairement définis. Cette étude de démonstration de faisabilité visait à évaluer la faisabilité de l'utilisation d'un bloc du plexus brachial (BPB) chez des patients éveillés comme modèle expérimental de la dysfonction nerveuse afin de caractériser les attributs de test diagnostique des potentiels évoqués somesthésiques (PES). MéTHODE: Nous avons enregistré les PES et la fonction neurologique de base des patients, puis administré des BPB (modèle expérimental) pour générer des états progressifs de dysfonction nerveuse. Nous avons surveillé simultanément les changements des PES (test pour déterminer l'indicateur) et les symptômes neurologiques (norme de référence) pendant l'évolution du BPB afin de déterminer les relations temporelles et les attributs de test diagnostique des PES. RéSULTATS: Le bloc du plexus brachial a produit une dysfonction motrice et sensorielle différentielle qui nous a permis de procéder à une évaluation clinique et neurophysiologique simultanée. Cent cinquante-sept paires de points de données multiples issues de 14 patients ont été incluses pour l'analyse finale. L'apparition de signaux de PES anormaux a presque toujours précédé l'apparition de symptômes neurologiques. Les sensibilités et les spécificités des PES pour détecter la perte de force (score moteur ≤ 4/5), la sensation de froid et la discrimination à deux points étaient de 100 % et 67 %, 99 % et 55 %, et 100 % et 46 %, respectivement. CONCLUSION: Cette étude a constaté que le bloc du plexus brachial peut produire une dysfonction nerveuse différentielle suffisante pour permettre l'évaluation adéquate des attributs de test diagnostique des PES en tant que moniteur nerveux. Les résultats de cette étude pourraient motiver d'autres travaux sur l'amélioration des modèles de dysfonction nerveuse peropératoire et des moniteurs diagnostiques de la fonction nerveuse. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT03409536); enregistrée le 24 janvier 2018.

Automated Nerve Monitoring in Shoulder Arthroplasty: A Prospective Randomized Controlled Study.

BACKGROUND: Evoked potential monitoring is believed to prevent neurologic injury in various surgical settings; however, its clinical effect has not been scrutinized. It was hypothesized that an automated nerve monitor can minimize intraoperative nerve injury and thereby improve clinical outcomes in patients undergoing shoulder arthroplasty. METHODS: A prospective, blinded, parallel group, superiority design, single-center, randomized controlled study was conducted. Study participants were equally randomized into either the automated nerve-monitored or the blinded monitored groups. The primary outcome was intraoperative nerve injury burden as assessed by the cumulative duration of nerve alerts. Secondary outcomes were neurologic deficits and functional scores of the operative arm, and the quality of life index (Euro Quality of life-5 domain-5 level score) at postoperative weeks 2, 6, and 12. RESULTS: From September 2018 to July 2019, 213 patients were screened, of whom 200 were randomized. There was no statistically significant difference in the duration of nerve alerts between the automated nerve-monitored and control groups (median [25th, 75th interquartile range]: 1 [0, 18] and 5 [0, 26.5]; Hodges-Lehman difference [95% CI]: 0 [0 to 1] min; P = 0.526). There were no statistically significant differences in secondary outcomes between groups. However, in the ancillary analysis, there were reductions in neurologic deficits and improvements in quality of life index occurring in both groups over the course of the study period. CONCLUSIONS: Protection from nerve injury is a shared responsibility between surgeons and anesthesiologists. Although a progressive improvement of clinical outcomes were observed over the course of the study in both groups as a consequence of the real-time feedback provided by the automated nerve monitor, this trial did not demonstrate that automated nerve monitoring by itself changes important clinical outcomes compared with no monitoring.

Cardiovascular Risk Assessment for Noncardiac Surgery: Are We Ready for Biomarkers?

Biomarkers aided perioperative cardiac assessment is a relatively new concept. Cardiac biomarkers with historical significance (aspartate transaminase, dehydrogenase, creatinine kinase and myoglobin) have paved the way for traditional biomarkers (cardiac troponin, C-reactive protein, lipoprotein). Contemporary biomarkers like natriuretic peptides (BNP and ProBNP) are validated risk markers in both acute and chronic cardiac diseases and are showing remarkable promise in predicting serious cardiovascular complications after non-cardiac surgery. This review is intended to provide a critical overview of traditional and contemporary biomarkers for perioperative cardiovascular assessment and management. This review also discusses the potential utility of newer biomarkers like galectin-3, sST-2, GDF-15, TNF-alpha, MiRNAs and many others that can predict inflammation, cardiac remodeling, injury and endogenous stress and need further investigations to establish their clinical utility. Though promising, biomarker led perioperative care is still in infancy and it has not been determined that it can improve clinical outcomes.

Ultrasound-guided subomohyoid suprascapular nerve block and phrenic nerve involvement: a cadaveric dye study.

BACKGROUNDS AND OBJECTIVES: The anterior approach to the subomohyoid suprascapular (SOS) nerve is a new, technically easy and reliable regional anesthesia technique for postoperative shoulder analgesia. However, due to its proximity, the injectate may spread to the brachial plexus and phrenic nerve. The goal of this anatomic study with dye injection in the subomohyoid space and subsequent cadaver dissection was to establish the likely spread of local anesthesia and the extent of brachial plexus and phrenic nerve involvement resulting from ultrasound-guided SOS nerve block. METHODS: The suprascapular nerve (SSN) under the inferior belly of omohyoid muscle in the posterior triangle of the neck was identified. Using a contrast dye, 10 ultrasound-guided SOS nerve injections of 5 mL were done bilaterally, in five fresh cadavers. The area was then dissected to evaluate the spread of the contrast dye in the immediate proximity of the brachial plexus, phrenic and SSN. RESULTS: The SSN and omohyoid muscle were easily identified on each cadaver. SOS nerve staining with contrast dye was seen in 90% of dissections. The superior trunk was stained in 90% and the middle trunk was stained in 80% of dissections. The inferior trunk was stained in 20% of dissections. A spread of dye around the SSN was observed in 90% and the phrenic nerve was mildly stained in 20% of the dissections. CONCLUSION: In-plane ultrasound-guided needle injection with a 5 mL volume for SOS block was sufficient to stain the SSN. This conservative volume involved other parts of the brachial plexus and may potentially spread to the phrenic nerve. Further clinical studies are required for confirmation.

Infraclavicular and supraclavicular approaches to brachial plexus for ambulatory elbow surgery: A randomized controlled observer-blinded trial.

STUDY OBJECTIVE: To compare the effectiveness of supraclavicular and infraclavicular approaches to brachial plexus block for elbow surgery. DESIGN: Prospective, parallel arm, observer-blinded, randomized controlled trial. SETTING: This study occurred in a designated block room at St. Joseph's hospital, a large academic tertiary hospital in London, Canada. PATIENTS: 150 adult ASA class I-III patients undergoing elective ambulatory elbow surgery. INTERVENTIONS: Patients were randomized to receive either an ultrasound-guided infraclavicular or a supraclavicular block with ropivacaine. MEASUREMENTS: Both groups were assessed for performance and sensory block onset times. Motor block, effective surgical anesthesia, procedure-related pain, axillary nerve block and ulnar nerve sparing were additional outcomes. We analyzed continuous and non-continuous variables with the independent t-test and chi-square test respectively and considered statistical significance when type 1 error was under 0.05. MAIN RESULTS: We observed similar mean block procedure times at 285 (±128) seconds in infra and 307 (±138) seconds in supra group (p = 0.3). The mean time of sensory block onset in both groups was similar: Infra 20.4 (±7.9) and supra 18.9 (±7.1) min (p = 0.4). Conversion to general anesthesia (4.2 vs 5.5%; p = 0.73) and the need for local anesthetic supplement (4.2 vs 4.1%; p = 0.98) was similar in both groups. We observed an increased incidence of paresthesia in the supra group (8.3 vs 23.2%; p = 0.014). CONCLUSION: We found that both blocks were equally effective for elbow surgery with similar procedure and block onset times and failure rates. Lower incidence of paresthesia was associated with the infraclavicular block with no change in other complications compared to the supraclavicular technique.

Programmed intermittent peripheral nerve local anesthetic bolus compared with continuous infusions for postoperative analgesia: A systematic review and meta-analysis.

STUDY OBJECTIVE AND BACKGROUND: The role of the programmed intermittent bolus (PIB) technique for infusion of local anesthetics in continuous peripheral nerve blockade (CPNB) remains to be elucidated. Randomized controlled trials (RCTs) on PIB versus continuous infusion for CPNB have demonstrated conflicting results and no systematic review or meta-analysis currently exists. We aimed to delineate via systematic review with meta-analysis if there is any analgesic benefit to performing PIB versus continuous infusion for CPNB. DESIGN: We conducted a systematic review and random-effects meta-analysis of RCTs. DATA SOURCES: We searched Medline, Embase, and the Cochrane Library without language restriction from inception to 2-May-2017. ELIGIBILITY CRITERIA: Included RCTs had to compare PIB to continuous infusion in adult surgical patients receiving any upper or lower limb CPNB for postoperative analgesia. VAS pain scores were the primary outcome. The Cochrane Risk of Bias Tool with GRADE methodology was utilized to assess evidence quality. RESULTS: Nine RCTs (448 patients) met the inclusion criteria. Two studies performed upper limb blocks and the rest lower limb blocks. Five RCTs activated the CPNB with long-acting local anesthetic and only five used multi-modal analgesia. PIB modestly reduced VAS pain scores at 6h (-14.2mm; 95%CI -23.5mm to -5.0mm; I2=82.5%; p=0.003) and 12h (-9.9mm; 95%CI -14.4mm to -5.4mm; I2=12.4%; p<0.001), but not at later time points. There were no other meaningful differences in the rest of the outcomes, apart from more residual motor block with PIB (OR 4.27; 95% CI 1.08-16.9; p=0.04; NNTH=8). GRADE scoring ranged from low to very low. CONCLUSIONS: The existing evidence demonstrates that PIB does not meaningfully reduce VAS pain scores in CPNB. This systematic review provides important information about the limitations of existing studies. Future studies should reflect contemporary practice and focus on more painful operations.

Ultrasound guided quadratus lumborum block for analgesia after cesarean delivery: case series / Bloqueio do quadrado lombar guiado por ultrassom para analgesia pós cesariana: série de casos

Abstract Introduction: The majority of women having planned cesarean section receive spinal anesthesia for the procedure. Typically, spinal opioids are administered during the same time as a component of multimodal analgesia to provide pain relief in the 16-24 h period postoperatively. The quadratus lumborum block is a regional analgesic technique that blocks T5-L1 nerve branches and has an evolving role in postoperative analgesia for lower abdominal surgeries and may be a potential alternative to spinal opioids. If found effective, it will have the advantage of a reduction in opioid associated adverse effects while providing similar quality of analgesia. Methods: We performed bilateral quadratus lumborum block in 3 women who received a spinal anesthetic for a cesarean delivery and evaluated their post-operative opioid consumption and patient satisfaction. Results: In all 3 patients, there was no additional opioid consumption during the first 24 h after the block. Numeric Rating Scale (NRS) for pain was less than 6 for the first 24 h. Women were all very satisfied with the quality of pain relief. Discussion: Quadratus lumborum block may be a promising anesthetic adjuvant for post-cesarean analgesia. Further randomized controlled trials are needed to compare the efficacy of the quadratus lumborum block with intrathecal opioids.

Resumo Introdução: A maioria das mulheres agendadas para cesariana recebe anestesia raquidiana para o procedimento. Tipicamente, os opioides administrados por via espinhal (VE) são administrados ao mesmo tempo como um componente da analgesia multimodal para proporcionar alívio da dor no período pós-operatório de 16-24 horas. O bloqueio do quadrado lombar (QL) é uma técnica de analgesia regional que bloqueia os ramos nervosos T5- L1 e tem um papel crescente na analgesia pós-operatória de cirurgias abdominais inferiores, pode ser uma potencial opção para os opioides VE. Se for considerado eficaz, esse bloqueio terá a vantagem de uma redução nos efeitos adversos associados aos opioides e proporcionará qualidade semelhante de analgesia. Métodos: O bloqueio bilateral do quadrado lombar foi feito em três mulheres que receberam raquianestesia para parto cesário e o consumo de opioides no pós-operatório e a satisfação das pacientes foram avaliados. Resultados: Em todas as três pacientes, não houve consumo adicional de opioide durante as primeiras 24 horas após o bloqueio. A escala de avaliação numérica (EAN) para dor foi inferior a 6 durante as primeiras 24 horas. Todas as mulheres ficaram muito satisfeitas com a qualidade do alívio da dor. Discussão: O bloqueio do QL pode ser um adjuvante promissor para analgesia pós-cesariana. Estudos randomizados e controlados são necessários para comparar a eficácia do bloqueio do quadrado lombar com opioides administrados por via intratecal.

[Ultrasound guided quadratus lumborum block for analgesia after cesarean delivery: case series]. / Bloqueio do quadrado lombar guiado por ultrassom para analgesia pós cesariana: série de casos.

INTRODUCTION: The majority of women having planned cesarean section receive spinal anesthesia for the procedure. Typically, spinal opioids are administered during the same time as a component of multimodal analgesia to provide pain relief in the 16-24h period postoperatively. The quadratus lumborum block is a regional analgesic technique that blocks T5-L1 nerve branches and has an evolving role in postoperative analgesia for lower abdominal surgeries and may be a potential alternative to spinal opioids. If found effective, it will have the advantage of a reduction in opioid associated adverse effects while providing similar quality of analgesia. METHODS: We performed bilateral quadratus lumborum block in 3 women who received a spinal anesthetic for a cesarean delivery and evaluated their post-operative opioid consumption and patient satisfaction. RESULTS: In all 3 patients, there was no additional opioid consumption during the first 24h after the block. Numeric Rating Scale (NRS) for pain was less than 6 for the first 24h. Women were all very satisfied with the quality of pain relief. DISCUSSION: Quadratus lumborum block may be a promising anesthetic adjuvant for post-cesarean analgesia. Further randomized controlled trials are needed to compare the efficacy of the quadratus lumborum block with intrathecal opioids.

A Comparison of Combined Suprascapular and Axillary Nerve Blocks to Interscalene Nerve Block for Analgesia in Arthroscopic Shoulder Surgery: An Equivalence Study.

BACKGROUND AND OBJECTIVES: The primary objective of this study was to compare the analgesic efficacy of combined suprascapular and axillary nerve block (SSAX) with interscalene block (ISB) after arthroscopic shoulder surgery. Our hypothesis was that ultrasound-guided SSAX would provide postoperative analgesia equivalent to ISB. METHODS: Sixty adult patients undergoing arthroscopic shoulder surgery received either SSAX or ISB prior to general anesthesia, in a randomized fashion. Pain scores, satisfaction, and adverse effects were recorded in the recovery room, 6 hours, 24 hours, and 7 days after surgery. RESULTS: Combined suprascapular and axillary nerve block provided nonequivalent analgesia when compared with ISB at different time points postoperatively, except on postoperative day 7. Interscalene block had better mean static pain score in the recovery room (ISB 1.80 [95% confidence interval [CI], 1.10-2.50] vs SSAX 5.45 [95% CI, 4.40-6.49; P < 0.001]). At 24 hours, SSAX had better mean static pain score (ISB 6.35 [95% CI, 5.16-7.54] vs SSAX 3.92 [95% CI, 2.52-5.31]; P = 0.01) with similar satisfaction between the groups. CONCLUSIONS: Combined suprascapular and axillary nerve block provides nonequivalent analgesia compared with ISB after arthroscopic shoulder surgery. While SSAX provides better quality pain relief at rest and fewer adverse effects at 24 hours, ISB provides better analgesia in the immediate postoperative period. For arthroscopic shoulder surgery, SSAX can be a clinically acceptable analgesic option with different analgesic profile compared with ISB.

Reduction in sodium content of local anesthetics for peripheral nerve blocks: a comparative evaluation of saline with 5% dextrose--a randomized controlled double-blind study.

BACKGROUND: Commercially available local anesthetic drugs when diluted with normal saline have high sodium content. High perineural sodium concentration has been implicated in antagonizing the analgesic effects of local anesthetics by preventing and/or delaying neural blockade. Five percent dextrose is not known to cause any short- or long-term injury when injected around neural tissue. In this study, we prospectively compared and evaluated block characteristics when local anesthetic drug was diluted with these 2 different agents. METHODS: Patients scheduled for upper limb surgery were randomly assigned to receive axillary brachial plexus block with 0.5% ropivacaine (1% diluted with either 5% dextrose or normal saline). Motor and sensory block were tested every 5 minutes for 30 minutes. Postoperatively, a telephone interview was conducted after 24 hours and 7 days along with surgical follow-up at days 3, 10, and/or 14 to 28 days to document side effects, patient satisfaction, and time for block resolution. Any nerve deficits were followed until resolution. The primary outcome was time to onset of sensory nerve block. RESULTS: Five hundred fifty patients were recruited for this study. The mean time to complete sensory block was 18.3 ± 6.1 minutes in the dextrose group and 22.5 ± 6.4 minutes in the saline group (P < 0.001, 95% confidence interval for mean difference 3.0-5.4 minutes). There were 5 patients with clinical nerve deficits (no statistical difference between groups). CONCLUSIONS: Dilution with 5% dextrose provides earlier onset of axillary brachial plexus block with ropivacaine.

Ultrasound-guided sciatic nerve block in infants and toddlers produces successful anesthesia regardless of the motor response.

BACKGROUND AND OBJECTIVES: The primary objective of this study was to assess the success rate of ultrasound-guided sciatic needle placement regardless of the motor stimulation in infants and toddlers. METHODS: Forty-five consecutive patients aged 7 months-2 years, scheduled for foot surgery, were included in this prospective, descriptive and blinded study. After induction of general anesthesia, sciatic nerve block was performed under ultrasound guidance in the subgluteal area using an insulated needle connected to a nerve stimulator, with the power off. At the precise point when it was presumed that the needle was touching the sciatic nerve, the peripheral nerve stimulator was turned on at 0.5 mA and the current was slowly decreased to 0.2 mA. Presence and location of any motor responses were observed and recorded. Statistical analysis was applied to compare the success rate in patients who did and did not exhibit a motor response to electrical stimulation. Postoperatively, block duration and analgesic consumption were recorded. RESULTS: The sciatic nerve could be distinctly visualized in 44 children, and all these blocks were successful. Only 22% patients showed any motor response to electrical stimulation. There was no significant difference in block characteristics between patients who exhibited a motor response with electrical stimulation and those who did not. CONCLUSION: Success rate of ultrasound-guided sciatic nerve block remains unaltered irrespective of motor response to neurostimulation.

Ultrasound-guided peripheral regional blockade in patients with Charcot-Marie-Tooth disease: a review of three cases.

PURPOSE: To describe the clinical presentation of three patients with Charcot-Marie-Tooth disease, who underwent uneventful upper limb surgery following successful peripheral nerve blockade, and to review the anesthetic implications in patients with Charcot-Marie-Tooth disease. CLINICAL FEATURES: In three patients with Charcot-Marie-Tooth disease presenting for surgery of the upper limb, the motor response, following nerve stimulation, was suboptimal. However, ultrasound guidance was effective in visualizing the needle-nerve interaction, and local anesthetic was injected around the nerves. Good block ensued and surgery proceeded in all patients without complications. No exacerbation of the neurological condition was observed in any patient. CONCLUSIONS: Charcot-Marie-Tooth disease is a demyelinating, hereditary, motor and sensory neuropathy characterized by abnormalities of nerve conduction. Regional anesthesia of the upper limb is feasible in these patients, and these cases show that ultrasound guidance makes peripheral nerve block possible in patients for whom traditional methods of nerve localization fail.