[Severe hypotension as a complication of intramyometrial injection of vasopressin: a case report].

A thirty-year-old woman was scheduled for laparoscopic myomectomy. After insertion of an epidural catheter at the L4-5 interspace, general anesthesia was induced with thiopental 250 mg followed by vecuronium 8mg intravenously to facilitate tracheal intubation. General anesthesia was maintained with sevoflurane and nitrous oxide. Just after intramyometrial injection of vasopressin, blood pressure decreased from 122/66 to 45/25 mmHg, and heart rate decreased from 52 to 45 beats x min(-1). The patient was ventilated with 100% oxygen, and we administered atropine 0.25 mg and ephedrine 16 mg intravenously. Blood pressure increased to 150/100 mmHg and heart rate increased to 135 beats x min(-1). Since electrocardiogram showed ST-segment depression and premature ventricular contraction, we administered nicorandil 3 mg followed by continuous infusion at a rate of 3 mg x hr(-1), and lidocaine 60 mg, intravenously. The ST depression and premature ventricular contraction disappeared immediately. To decrease blood pressure and heart rate, we increased inspiratory concentrations of sevoflurane and nitrous oxide and administered local anesthetics via epidural catheter, and hemodynamic parameters became gradually stable. We estimate that severe hypotension observed in this case is associated with intramyometrial injection of vasopressin. Increased blood concentration of vasopressin might cause vasoconstriction of coronary artery, increases in afterload, and/or direct myocardial depression resulting in decreased cardiac output.