[The effect of continuous epidural infusion of combination of buprenorphine and bupivacaine for postoperative pain relief using a portable 0.5 ml.h-1 type infuser with patient control module].

Using a portable 0.5 ml.h-1 type infuser with Patient Control Module (Baxter infuser BB+ PCM), we compared patients receiving continuous epidural infusion with patients using self controlled analgesia system for postoperative analgesia after upper abdominal surgery. Twenty-one patients were randomized into three groups: group I (n = 7) received 20 micrograms.h-1 of buprenorphine (Bu) with additional 20 micrograms of Bu; group II (n = 7) 20 micrograms.h-1 of Bu plus 1 mg.h-1 of bupivacaine (Bup) with additional 20 micrograms of Bu plus 1 mg of Bup; group III (n = 7) 20 micrograms.h-1 of Bu plus 2 mg.h-1 of Bup with additional 20 micrograms of Bu plus 2 mg of Bup. In all three groups, patients received supplemental Bu 0.1 mg intramuscularly as needed. During 48-hours postoperatively, we evaluated verbal descriptor pain scale, sedative scale, visual analogue scale, supplemental doses of Bu, and side effects. Total doses of Bu during the first 12 hours were significantly larger than those during other 12-hour period in all the groups (P < 0.05). In each period during the 12 to 48-hours after operation, the percentage of the patients who needed no supplemental Bu was 71.4-100%, which is higher than during the 0 to 12-hours (47.7%). There was no significant difference in verbal descriptor pain scale, sedative scale, visual analogue scale, and the incidence of side-effect among the three groups. Continuous epidural infusion with Bu using a portable 0.5 ml.h-1 type infuser with patient control module was effective for alleviating postoperative pain except in the first 12-hour period. However, addition of Bup to Bu did not improve the quality of postoperative epidural analgesia.