Comparison between Single- and Double-Injection Technique for Ultrasound-Guided Supraclavicular Block: A Randomized Controlled Study

Background: The supraclavicular approach to brachial plexus block is a commonly employed regional anesthesia technique for providing surgical anesthesia and postoperative analgesia for patients undergoing upper limb fractures. With ultrasound (US) guidance, the success rate of the block is increased, and complications like pneumothorax and vascular puncture are minimized. The block can be performed using single injection at the corner pocket or double injection, that is, half of the drug at the corner pocket and the remaining half at the cluster of brachial plexus divisions. Methods: After institutional ethics committee approval, we randomized 40 patients scheduled with fractures for elective upper extremity surgery under US-guided supraclavicular brachial plexus block. Twenty patients received 30 mL of local anesthetic at the corner pocket (group SI), and 20 patients received 30 mL of local anesthetic using the dual-injection technique in divided doses (group DI). Demographic data, time to block performance, time to sensory and motor block, total anesthesia-related time (TART), block success, and failure were compared between both groups. Results: The demographic data were comparable between both groups. The DI group had a significantly faster onset than the SI group (p = 0.0172). There was a statistically significant lesser performance time in group SI than in group DI (p < 0.034). The sensory and motor block achieved was comparable between both groups. Conclusion: The success rates in both the SI and DI techniques are comparable. The DI technique results in a faster onset and hence a shorter TART; however, it may not be clinically relevant.