176 CANADIAN JOURNAL OF ANESTHESIA

Purpose: The purpose of this study is to determine if real time ultrasound guidance improves the success rate of axillary bra-chial 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 supplementa