[Continuous epidural buprenorphine for postoperative pain relief in upper abdominal surgery]

To evaluate postoperative analgesia and side effects of epidural buprenorphine, 100 patients who underwent upper abdominal surgery were divided into 5 groups. All patients were given initially 0.1 mg of buprenorphine in 8 ml of 0.25% bupivacaine in bolus. Following an epidural bolus, 20 patients in each group were given 0.25% bupivacaine alone (group A), 5 micrograms buprenorphine in 1 ml of 0.25% bupivacaine (group B), 8 micrograms buprenorphine in 1 ml of 0.25% bupivacaine (group C), 12 micrograms buprenorphine in 1 ml of 0.25% bupivacaine (group D), or 15 micrograms buprenorphine in 1 ml of 0.25% bupivacaine (group E) with a portable disposable device at a rate of 1 ml.h-1 for 48 h. The analgesic efficacy in group E was superior to that in groups A, B, C and D. No significant difference was found in the incidence of side-effect among 5 groups. Therefore, epidural buprenorphine 15 micrograms in 1 ml of 0.25% bupivacaine given to patients at a rate of 1 ml.h-1 was thought to be optimal for postoperative pain relief in upper abdominal surgery in terms of its efficacy and side effects. However, 35% of these patients required supplementary systemic analgesics in the early postoperative period.