Background: This prospective, randomized, observer-blinded study compared ultrasound-guided supraclavicular (SCB), infraclavicular (ICB), and axillary (AXB) brachial plexus blocks for upper extremity surgery of the elbow, forearm, wrist, and hand.

Methods: One hundred twenty patients were randomly allocated to receive an ultrasound-guided SCB (n = 40), ICB (n = 40), or AXB (n = 40). Performance time (defined as the sum of imaging and needling times) and the number of needle passes were recorded during the performance of the block. Subsequently, a blinded observer recorded the onset time, block-related pain scores, success rate (surgical anesthesia), and the incidence of complications. The main outcome variable was the total anesthesia-related time, defined as the sum of performance and onset times.

Results: No differences were observed between the 3 groups in terms of total anesthesia-related time (23.1-25.5 mins), success rate (95%-97.5%), block-related pain scores, vascular puncture, and paresthesia. Compared with the supraclavicular and infraclavicular approaches, ultrasound-guided AXBs required a higher number of needle passes (6.1 [SD, 2.0] vs 2.0-2.6 [SD, 1.1-1.8]; both P ≤ 0.001), a longer needling time (7.4 mins [SD, 2.2 mins] vs 4.9-5.5 mins [SD, 1.9-4.2 mins]; both P ≤ 0.016), and a longer performance time (8.5 mins [SD, 2.3 mins] vs 6.0-6.2 mins [SD, 2.1-4.5 mins]; both P ≤ 0.008). Supraclavicular blocks resulted in a higher rate of Horner syndrome (37.5% vs 0%-5%; both P < 0.001).

Conclusion: Adjunctive ultrasonography results in similar success rates, total anesthesia-related times, and block-related pain scores for the SCB, ICB, and AXB.