Comparison of Ultrasound-guided Corner Pocket and Two Aliquots Injection Techniques for Supraclavicular Block in Upper-limb Orthopedic Surgeries: A Prospective Randomized Study

This is the authors' abstract. We don't add key points for this paper.

Objectives: The two approaches described for ultrasound-guided supraclavicular brachial plexus block are single injection (SI) at corner pocket technique and drug injection in two or more aliquots. A prospective, randomized, controlled study was conducted to compare the SI at the corner pocket with the double-injection (DI) ultrasound-guided supraclavicular brachial plexus block. Our study hypothesis was that the DI technique results in a faster onset time of the block and a lower failure rate as compared to the SI, corner pocket technique. The primary objective of the study was to compare the anesthesia onset time in SI versus DI technique in ultrasound-guided supraclavicular brachial plexus block for orthopedic surgeries of the upper limb. Materials and Methods: Fifty adult patients of the American Society of Anesthesiologists physical status I and II scheduled for hand, wrist, forearm, and elbow orthopedic surgeries were randomized into two groups, SI at corner pocket ( n = 25) and DI ( n = 25). The drug used in both groups was 20 mL of 0.5% bupivacaine with 1 mcg/kg clonidine solution. The performance time, anesthesia onset time, surgical anesthesia, failed block, and any complications were noted by a blinded observer. Results: The mean anesthesia onset time was longer in SI (17.7 min [Standard deviation (SD) = 4.55 min]) as compared to DI (12.8 min [SD = 3.93 min]). The DI group had a quicker onset of sensory anesthesia as well as motor blockade of all 4 nerves, i.e., musculocutaneous, radial, and median nerves at 15 min and ulnar nerve at 20 min. The time to first rescue analgesic dose was earlier in the SI group (11.18 h [SD = 1.56]) than in the DI group (12.89 h [SD = 1.87]). Prolonged duration of anesthesia (12.79 [SD = 1.7] vs. 9.76 [SD = 3.96] h, P < 0.001) was observed in the DI group as compared to the SI group. Conclusion: DI ultrasound-guided supraclavicular block had a faster onset time, provided prolonged postoperative analgesia, and thus, a delayed demand for rescue analgesics than SI technique.