Supraclavicular brachial plexus block: a comparative clinical study between bupivacaine and levobupivacaine.

BACKGROUND AND OBJECTIVES Brachial plexus block is used in surgical procedures of the upper limbs. The brachial plexus is a potential territory for absorption of local anesthetics. Studies on bupivacaine isomers have shown reduced cardiovascular toxicity of its levorotatory form (levobupivacaine). However, the anesthetic efficacy (sensorial and motor blockades) of levobupivacaine in neuroaxis blocks has been debated. The objective of this study was to demonstrate the anesthetic efficacy of levobupivacaine in brachial plexus block, using the perivascular subclavian approach, by comparing it to racemic bupivacaine. METHODS Fifty adult patients of both genders, ASA I and II, underwent subclavian perivascular brachial plexus block, with the aid of a peripheral neurostimulator, for orthopedic surgeries of the upper limbs. Patients were randomly divided into two groups: G BUPI - racemic bupivacaine, and G LEVO - levobupivacaine, and they received 30 mL of the 0.5% solution. Sensorial blockade was evaluated by pinprick stimulation from C5 to C8 metameres; and the motor blockade was assessed 1, 2, 5, 10, 15, 20, 25, and 30 minutes after the administration of the local anesthetic or until blockade of fingers, hand, forearm, and arm movements was observed. RESULTS Statistical differences in latency, failure rate, and degree of the motor blockade, and failure of the sensorial blockade between both groups were not observed, but the latency of the sensorial blockade in all metameres analyzed showed statistically significant differences. Adverse events inherent to the administration of local anesthetics were not observed. CONCLUSIONS The anesthetic efficacy of levobupivacaine in brachial plexus block was similar to that of the racemic solution commonly used.