[Continuous epidural buprenorphine for postoperative pain relief in patients after lower abdominal surgery]

Postoperative analgesia with epidurally injected buprenorphine and its side effects were investigated in 100 patients who had received lower abdominal surgery. All patients received initially 8 ml of bupivacaine and 0.1 mg of buprenorphine. Following bolus epidural injection, five different groups of 20 patients each received either bupivacaine alone (group A), 5 micrograms.ml-1 buprenorphine.bupivacaine mixture (group B), 8 micrograms.ml-1 buprenorphine.bupivacaine mixture (group C), 12 micrograms.ml-1 buprenorphine.bupivacaine mixture (group D), or 15 micrograms.ml-1 buprenorphine.bupivacaine mixture (group E) by a portable disposable device at a rate of 1 ml.h-1 for 48 h. The analgesic efficacy in group E was superior to those in groups A, B, C or D. No significant difference in the incidence of side-effect was found among groups C, D, E. We conclude that a dose of a approximately 15 micrograms.h-1 might be optimal for postoperative pain relief after lower abdominal surgery.