IV compared with brachial plexus infusion of butorphanol for postoperative analgesia

In a randomized, double-blind, controlled study, we have compared two groups of patients receiving either continuous systemic i.v. or continuous brachial plexus infusion of butorphanol for analgesia after operations on the upper extremities. Twenty-two patients undergoing elective upper extremity surgery were allocated randomly to one of two groups to receive either butorphanol i.v. and saline injected into the brachial plexus sheath (i.v. group) or butorphanol injected into the brachial plexus sheath and saline i.v. (brachial plexus group). After surgery on the upper extremity under continuous axillary brachial plexus block, each patient received a continuous infusion of butorphanol either i.v. or into the brachial plexus sheath at a dose of 83.3 micrograms h-1. Concurrently, a saline infusion was given via the alternate route. Patients rated their pain on a 10-cm visual analogue scale (VAS). VAS scores in the two groups did not differ up to 6 h and 24 h after operation. From 9 h until 24 h after operation, pain scores were significantly higher in the i.v. group than in the brachial plexus group. The VAS score 9 h after operation was 3.3 (SD 2.7) in the i.v. group and 0.6 (0.9) in the brachial plexus group (P < 0.01); 12 h after operation 2.7 (1.8) in the i.v. group and 0.6 (0.9) in the brachial plexus group (P < 0.01); 18 h after operation 1.7 (1.0) in the i.v. group and 0.7 (1.0) in the brachial plexus group (P < 0.05); and 24 h after operation 3.2 (2.4) in the i.v. group and 0.7 (1.2) in the brachial plexus group (P < 0.01). We conclude that continuous injection of butorphanol into the brachial plexus sheath provided superior analgesia compared with continuous i.v. injection.