I.v. compared with brachial plexus infusion of butorphanol for postoperative analgesia

In a randomized, double-blind, controlled study, we have comparedtwo groups of patients receiving either continuous systemici.v. or continuous brachial plexus infusion of butorphanol foran algesia after operations on the upper extremities. Twenty-twopatients undergoing elective upper extremity surgery were allocatedrandomly to one of two groups to receive either butorphanoli.v. and saline injected into the brachial plexus sheath (i.v.group) or butorphanol injected into the brachial plexus sheathand saline i.v. (brachial plexus group). After surgery on theupper extremity under continuous axillary brachial plexus block,each patient received a continuous infusion of butor phanoleither i.v. or into the brachial plexus sheath at a dose of83.3 µg h^–1. Concurrently, a saline infusion wasgiven via the alternate route. Patients rated their pain ona 10-cm visual analogue scale (VAS). VAS scores in the two groupsdid not differ up to 6 h and 24 h after operation. From 9 huntil 24 h after operation, pain scores were significantly higherin the i.v. group than in the brachial plexus group. The VASscore 9 h after operation was 3.3 (SD 2.7) in the i.v. groupand 0.6 (0.9) in the brachial plexus group (P < 0.01); 12h 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 operation1 .7 (1.0) in the i.v. group and 0.7 (1.0) in the brachial plexusgroup (P < 0.05); and 24 h after operation 3.2 (2.4) in thei.v. group and 0.7 (1.2) in the brachial plexus group (P <0.01). We conclude that continuous injection of butorphanolinto the brachial plexus sheath provided superior analgesiacompared with continuous i.v. injection.