An unusual toxic reaction to axillary block by mepivacaine with adrenaline

An increase in blood pressure, accompanied by atrial fibrillation, agitation, incomprehensible shouts and loss of consciousness, was observed in an elderly, ASA classification group II, cardiovascularly medicated male, 12 min after performance of axillary block with mepivacaine 850 mg containing adrenaline 0.225 mg, for correction of Dupuytren's contracture. After intravenous administration of labetalol, metoprolol and midazolam the patient's condition improved, and 15 min later he woke up. The block was successful and surgery was conducted as scheduled despite persisting atrial fibrillation. Postoperatively, the patient refused DC cardioversion and was treated medically. Both the temporal relationship of events and the response to treatment suggest that a rapid systemic absorption of mepivacaine with adrenaline and/or interaction of these drugs with the patient's cardiovascular medications were responsible for the perioperative complications.