Bupivacaine: a safe local anesthetic for wrist blocks.

Seventy-one patients having minor hand surgical procedures under wrist block anesthesia were studied, with the goal of identifying a possible neurotoxic potential of bupivacaine when used according to standard clinical practice. This drug was compared with lidocaine at equipotent analgesic concentrations (bupivacaine: 5 mg/ml; lidocaine: 20 mg/ml) by use of a double-blind randomized protocol. At postoperative follow-up, four (5.6%) patients had new neurologic symptoms. Mechanical factors, e.g., nerve manipulation during surgery, or nerve trauma during performance of the block, were identified in three patients. In the remaining patient, anesthesia was induced with lidocaine, and no cause could be identified. It was concluded that bupivacaine, when used in clinical concentrations, is not associated with an increased incidence of neural complications.