A Comparative Analysis of Supraclavicular Nerve Block Techniques in Upper Limb Surgery: Nerve Stimulator vs. Ultrasound Guidance

Abstract

Background: The traditional method of employing a Peripheral Nerve Stimulator (PNS) has long been considered the benchmark for peripheral nerve blocks when ensuring precise needle positioning for regional anesthesia and pain relief [1]. In contrast, contemporary ultrasound (US) technology offers a safer alternative for guiding the injection needle, reducing the likelihood of harming nearby structures. The primary aim of this study was to evaluate and compare the efficacy of two techniques: one using a nerve stimulator as a guide and the other relying on ultrasound guidance for performing a supraclavicular brachial plexus block in upper limb surgical procedures. Methods: A prospective, randomized, single-blind comparative study was undertaken involving a total of one hundred patients who underwent a supraclavicular brachial plexus block using 0.5 Ropivacaine at Department of Anesthesia, KIMS, Karad. The study received approval from the ethical committee [2], [3]. The patients were allocated randomly into two groups: group PNS (n = 50) and group US (n = 50). The study assessed and compared procedure time, onset and duration of sensory and motor blockade, as well as any associated complications within both groups. Results: In group PNS, the procedure took an average of 9.0 ± 1.50 minutes, whereas in group US, it was notably shorter at 6.07 ± 1.20 minutes (p < 0.0001). The onset of sensory and motor blocks in group PNS occurred at 7.48 ± 1.23 minutes and 9.64 ± 1.08 minutes, respectively, while in group US, these onsets were quicker at

6.26 ± 1.02 minutes and 8.20 ± 1.02 minutes, respectively (p < 0.0001). Group US also demonstrated a shorter time to achieve

complete block, with an average of 13.64 ± 1.11 minutes, compared to 16.21 ± 1.54 minutes in group PNS (p < 0.0001). Regarding the duration of sensory and motor block, group PNS had blocks that lasted 6 hours for sensory and 5 hours for motor, whereas in group US, these durations were longer, lasting 7 hours for sensory and 6 hours for motor [4]. Additionally, the success rate was 90% in group PNS and notably higher at 97.5% in group US. Conclusion: The study demonstrated a significant superiority of the ultrasound-guided technique over the peripheral nerve stimulator (PNS) for performing the supraclavicular brachial plexus block.