A multicentre trial of ropivacaine 7.5 mg · ml-1 vs bupivacaine 5 mg · ml-1 for supra clavicular brachial plexus anesthesia

Abstract

Purpose: To compare the efficacy of ropivacaine 7.5 mg·ml-1 with bupivacaine 5.0 mg·ml-1 for subclavian perivascular brachial plexus block. Methods: After informed consent, 104 ASA I-III adults participated in a randomized, double-blind, multi-center trial to receive 30 ml of either ropivacaine 7.5 mg·ml-1 or bupivacaine 5.0 mg·ml-1 for subclavian perivascular brachial plexus block prior to upper limb surgery. Onset and duration of sensory and motor block in the distribution of the axillary, median, musculo-cutaneous, radial and ulnar nerves were assessed. Results: Onset times and duration of sensory and motor block were similar between groups. Mean duration of analgesia for the five nerves was between 11.3 and 14.3 hr with ropivacaine and between 10.3 and 17.1 hr with bupivacaine. Quality of muscle relaxation judged as excellent by the investigators was not significantly different (ropivacaine - 35/49, bupivacaine - 30/49). The median time to first request for analgesia was comparable between the two groups (11-12 hr). One patient developed a grand mal seizure shortly after receiving bupivacaine and recovered consciousness within 30 min. There were no serious adverse events in the ropivacaine group. Conclusions: Thirty ml ropivacaine 7.5 mg·ml-1 (225 mg) produced effective and well tolerated brachial plexus block of long duration by the subclavian perivascular route. In this study, the results were similar to those of 30 ml bupivacaine 5.0 mg·ml-1.