2022 Volume 81 Issue 4 Pages 205-211
No study has investigated the minimum effective volume of 0.5% levobupivacaine for ultrasound-guided brachial plexus block via the axillary approach. To address this deficit, we sought to determine the minimum effectivevolume and evaluate the clinical efficacy of low volumes. Our study included 25 patients scheduled to undergoupper limb surgery. The minimum effective volume was determined with Dixon’s positive-negative up-and-downmethod. The study design called for a starting volume of 5 mL per nerve for the first patient, with the volume tobe decreased by 0.5 mL for the next patient if the block was successful or increased by 0.5 if the block was unsuccessful. The minimum volume was set at 1 mL. The minimum effective volume, duration of analgesia, time toonset, and use of analgesics during surgery were determined. The block success rate was 100%. The volume wasdecreased to 1 mL without block failure, and block success was achieved in the remaining 16 patients with 1 mL.The duration of analgesia was 11.2 ± 4.7 hours and was not correlated with the dose. No analgesics were usedduring surgery. These findings suggest that 1 mL of 0.5% levobupivacaine per nerve provides sufficient analgesia.