A multicentre trial of ropivacaine 7.5 mg center dot ml(-1) vs bupivacaine5 mg center dot ml(-1) for supra clavicular brachial plexus anesthesia

Purpose: To compare the efficacy of ropivacaine 7.5 mg.ml(-1) with bupivaca ine 5.0 mg.ml(-1) for subclavian perivascular brachial plexus block. Methods: After informed consent, 104 ASA 1-111 adults participated in a ran domized, double-blind, multi-center trial to receive 30 ml of either ropiva caine 7.5 mg.ml(-1) or bupivacaine 5.0 mg.ml(-1) for subclavian perivascula r brachial plexus block prior to upper limb surgery, Onset and duration of sensory and motor block in the distribution of the axillary, median, muscul o-cutaneous, radial and ulnar nerves were assessed. Results: Onset times and duration of sensory and motor block were similar b etween groups, Mean duration of analgesia for the five nerves was between 1 1.3 and 14.3 hr with ropivacaine and between 10.3 and 17.1 hr with bupivaca ine. 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 a fter 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 effectiv e and well tolerated brachial plexus block of long duration by the subclavi an perivascular route, In this study, the results were similar to those of 30 mi bupivacaine 5.0 mg.ml(-1).