Background and Objectives This prospective, randomized, and single-blind study compared effectiveness, performance, onset, and total anesthetic time and complications of the multiple axillary block (median, radial, and musculocutaneous nerves) with the humeral approach.

Methods One hundred patients were randomly assigned to 2 groups. In group A (axillary) median, radial, and musculocutaneus nerves were located by a nerve stimulator and injections were made. In group H (humeral) all 4 terminal nerves of the brachial plexus were located and injections were made. A total of 40 mL mepivacaine of 1% was used.

Results Complete sensory block of all 6 peripheral nerves occurred in 94% and 79% of patients in groups A and H, respectively (P < .05). The time to perform the block was shorter in group A (8 ± 4 minutes v 11 ± 4 minutes; P < .001); onset time was shorter in group A (16 ± 8 minutes v 21 ± 9 minutes; P < .05); total anesthetic time was shorter in group A (24 ± 8 minutes v 33 ± 10 minutes; P < .0001). Complete motor block was greater in group A (88% v 66%; P < .05). More vascular punctures occurred in group A (22% v 8%, P < .05).

Conclusion The triple-injection axillary block was more effective than the humeral approach as it was associated with more cases of sensory and complete motor block and gave shorter performance and onset times.