Axillary brachial plexus block with ropivacaine 7.5 mg/ml - A comparative study with bupivacaine 5 mg/ml

Background: Ropivacaine is less cardiotoxic than bupivacaine and may be use d in higher doses in order to increase the quality of a block. The aim of t his study was to compare the efficacy and safety of 40 ml ropivacaine 7.5 m g/ml (300 mg) and 40 mi bupivacaine 5 mg/ml (200 mg) for axillary plexus bl ock. Methods: One hundred and four adult patients were included in a prospective , double-blind study. Sensory and motor block were tested for the five main terminal nerves of the arm at 10-min intervals until start of surgery and every second hour thereafter until full resolution of the block. Results: The overall evaluation of the block by the surgeon and the anesthe siologist showed a significantly better quality in the ropivacaine patients , regarding both anesthesia and motor block. There were no differences in t he time to onset and duration of the block. Except for one patient, who had seizures after an accidental IV injection of ropivacaine, there were no ma jor side effects. Conclusion: Ropivacaine 7.5 mg/ml, 40 ml, produces axillary plexus block of similar onset and duration but better quality than 40 ml of bupivacaine 5. 0 mg/ml.