Determining the Minimum Effective Volume of Local Anesthetics for Ultrasound-Guided Supraclavicular Brachial Plexus Block

Abstract

This study aims to identify the minimum effective volume of local anesthetics required for an ultrasound-guided supraclavicular brachial plexus block (BPB). Proper identification of this volume could enhance pain management while minimizing potential complications associated with higher volumes.
A total of 60 patients undergoing upper limb surgery were enrolled in this randomized, double-blind study. Participants were divided into three groups receiving varying volumes of local anesthetic: 15 mL, 20 mL, and 25 mL of a 0.25% bupivacaine solution. The onset time, quality of anesthesia, and duration of sensory and motor block were evaluated. Pain scores were assessed using a visual analog scale (VAS) postoperatively at 1, 6, and 12 hours. Results indicated that the 20 mL volume provided adequate anesthesia with a faster onset and longer duration compared to the 15 mL group, while the 25 mL group did not show significant benefits. These findings suggest that 20 mL may be the optimal volume for effective analgesia in ultrasound-guided supraclavicular BPB, offering a balance between efficacy and safety.

Keywords: supraclavicular brachial plexus block, local anesthetics, ultrasound-guided, minimum effective volume, bupivacaine.