Purpose: The purpose of this study is to determine if real time ultrasound guidance improves the success rate of axillary brachial plexus blockade. Methods:Patients undergoing elective hand surgery were randomly assigned to one of three groups. Axillary blocks were performed using three motor response endpoints in the nerve stimulator (NS) Group, real-time ultrasound guidance in the ultrasound (US) Group and combined ultrasound and nerve stimulation in the USNS Group. Following administration of a standardized solution containing 2% lidocaine with 1:200,000 epinephrine and 0.5% bupivacaine (total 42 mL), sensory and motor functions were assessed by a blinded observer every five minutes for 30 min. A successful block was defined as complete sensory loss in the median, radial and ulnar nerve distribution by 30 min. The need for local and general anesthesia supplementation and post-block adverse events were documented. Results:One hundred and eighty-eight patients completed the study. Block success rate was higher in Groups US and USNS (82.8% and 80.7%) than Group NS (62.9%) (P = 0.01 and 0.03 respectively). Fewer patients in Groups US and USNS required supplemental nerve blocks and/or general anesthesia. Postoperatively, axillary bruising and pain were reported more frequently in Group NS. Conclusion: This study demonstrates that ultrasound guidance, with or without concomitant nerve stimulation, significantly improves the success rate of axillary brachial plexus block. EG et EGNS (82,8 % et 80,7 %) que dans le groupe NS (62,9 %) (P = 0,01 et 0,03 respectivement Méthode : Des patients devant subir une chirurgie élective de la main ont été randomisés en trois groupes. Des blocs axillaires ont été effectués en utilisant : trois points de réponses motrices dans le groupe neurostimulateur (NS), l'échoguidage en temps réel dans le groupe échographie (EG), et l'échographie combinée à la stimulation nerveuse dans le troisième groupe (EGNS

Compared with FNB, ACB results in significant quadriceps motor sparing and significantly preserved balance.