[Continuous epidural buprenorphine for postoperative pain relief after thoracotomy]

To evaluate postoperative analgesia and side effects of epidural buprenorphine, 60 patients after thoracotomy were divided into 6 groups. All patients received a bolus epidural administration of buprenorphine 0.1 mg in 8 ml of 0.25% bupivacaine. Following this epidural bolus, 10 patients in each group were given 0.25% bupivacaine alone (group A), buprenorphine 5 micrograms in 1 ml of 0.25% bupivacaine (group B), buprenorphine 8 micrograms in 1 ml of 0.25% bupivacaine (group C), buprenorphine 12 micrograms in 1 ml of 0.25% bupivacaine (group D), buprenorphine 15 micrograms in 1 ml of 0.25% bupivacaine (group E) or buprenorphine 18 micrograms in 1 ml of 0.25% bupivacaine (group F) with a portable disposable device at a rate of 1 ml.h-1 for 48 h. The percentages of patients who did not need additional narcotics for the first 24 hours postoperatively in group A, B, C, D, E, and F were 20%, 40%, 30%, 50%, 60%, and 70%, respectively. Those for the second 24 hours postoperatively in each group were 40%, 50%, 70%, 60%, 90%, and 90%, respectively. No significant difference in the incidence of side-effect was found among 6 groups. We concluded that optimal epidural doses of buprenorphine for post-thoracotomy pain relief are 15 and 18 micrograms.h-1 in the first and second 24 hours postoperatively, respectively.