Comparison of anesthetic effect between 0.375% ropivacaine versus 0.5% lidocaine in forearm intravenous regional anesthesia

Background and Objectives: Ropivacaine was shown to provide superior postblock analgesia to lidocaine in intravenous regional anesthesia (IVRA) in voluntary studies. The objective of this study was to compare the anesthesia efficacy, postblock analgesia, and local anesthetic-related side effects between ropivacaine and lidocaine when forearm IVRA was used. Methods: Fifty-one patients undergoing outpatient hand surgery were randomized to receive forearm IVRA with either ropivacaine 0.375% or lidocaine 0.5%. The volume was 0.4 mL/kg up to 25 mL. Sensation to pinching by forceps and motor function was assessed at 5-minute intervals up to 15 minutes. After tourniquet deflation, verbal pain rating score (VRPS) at 15-minute intervals for the first 2 hours and time for first analgesic in the first 24 hours were evaluated. Results: Eleven patients were excluded from the study with 20 patients remaining in each group. Onset time of anesthesia (6.5 +/- 2.9 minutes v 8.0 +/- 4.1 minutes for lidocaine and ropivacame groups, respectively) and motor block were similar. In the postoperative period, VPRS was significantly lower in the ropivacaine group in the first 60 minutes (median, 0; P < .05) with significantly more patients in the ropivacaine group pain free (VPRS, 0) up to the first 90 minutes (P > .05). More patients in lidocaine group requested analgesic in the first 2 hours postblock, and only patients in the lidocaine group required supplemental IV morphine in the recovery room. Twenty-four hour analgesic consumption was the same. No local anesthetic-related side effects were observed. Conclusions: We conclude that 0.375% ropivacaine provides effective anesthesia and superior postoperative analgesia compared with 0.5% lidocaine when forearm IVRA is used.