Contribution of ultrasound guidance to the performance of the axillary brachial plexus block with multiple nerve stimulation]

To evaluate whether ultrasound imaging of vascular nerve structures improves anesthetic block quality and decreases the incidence of vascular puncture in the performance of an axillary brachial plexus block with multiple nerve stimulation.Randomized trial enrolling 129 patients assigned to 2 groups. In group 1, axillary brachial plexus nerves were located by nerve stimulation with ultrasound guidance. In group 2, only conventional multiple nerve stimulation was used. We analyzed the number of nerves located, time required to perform the block, anesthetic quality, and the number of accidental vascular punctures.Four nerves were located in 43% of the patients in group 1 and 38% of those in group 2. More time was taken in performing the block in group 1 than in group 2 (mean [SD] of 350 [40] seconds vs. 291 [58] seconds, respectively; P < .05). The incidence of vascular puncture was significantly lower in group 1 (8%) than in group 2 (28%) (odds ratio, 4 [95% confidence interval, 2-13]; P < .01). Ten and 20 minutes after puncture, the quality of sensory and motor blockade was significantly better in group 1. Block success was similar in the 2 groups (98.5% and 94% respectively).Combining ultrasound guidance with nerve stimulation improves the anesthetic quality of an axillary brachial plexus block, decreases the likelihood of vascular puncture, and slightly increases the amount of time required to perform the procedure.