Brachial plexus anesthesia with verapamil and/or morphine.

Abstract

Calcium channel blockers potentiate the analgesic properties of both local anesthetics and opioids. We examined the analgesic effects of administering morphine, verapamil, or its combination into the brachial plexus sheath with lidocaine in 75 patients undergoing upper extremity orthopedic surgery. All patients received brachial plexus anesthesia with 40 mL of 1.5% lidocaine and epinephrine 5 microg/mL. In addition, patients were randomized to 1 of 5 groups: Group 1 received IV saline; Group 2 received IV verapamil 2.5 mg and morphine 5 mg; Group 3 received IV verapamil 2.5 mg and morphine 5 mg was added to the lidocaine solution; Group 4 received IV morphine 5 mg and verapamil 2.5 mg was added to the lidocaine solution; and Group 5 received verapamil 2.5 mg and morphine 5 mg were added to the lidocaine solution. Postoperatively, patients rated their pain (0-10) at 1, 6, 12, and 24 h. Patients were instructed to take 1 acetaminophen 325 mg/oxycodone 5 mg tablet every 3 h whenever the pain score exceeded 3. Analgesic duration was significantly increased in those patients receiving brachial plexus blocks with morphine (Groups 3 and 5) (P < 0.005). The total 24 h acetaminophen/oxycodone use was also less in Groups 3 and 5 (P < 0. 03). Duration of anesthesia (time of abolition of pinprick response) was significantly increased in those patients receiving brachial plexus blocks with verapamil (Groups 4 and 5) (P = 0.002). We conclude that the addition of verapamil to brachial plexus block with lidocaine can prolong the duration of sensory anesthesia, but it had no effect on analgesic duration of 24 h analgesic use. The addition of verapamil to brachial plexus block with lidocaine and morphine prolongs the duration of sensory anesthesia, but has no effect on analgesic duration or 24 h analgesic use.