Comparison of bupivacaine-fentanyl versus bupivacaine-morphine for patient controlled epidural analgesia

Analgesic efficacy and possible side effects of bupivacaine-fentanyl (BF) and bupivacaine-morphine (BM) combinations for patient controlled epidural analgesia (PCEA) have been compared. Sixty ASA I-II patients who had PCEA following lower abdominal surgery were admitted to the study. Epidural catheter was inserted at the level of L3-4 or L4-5 following induction of general anesthesia. In Group BF epidural drug solution was prepared as bupivacaine 0.1 % and fentanyl 2 mu g/ml. In Group BM, solution was prepared as bupivacaine 0.1 % and morphine 0.2 mu g/ml. In both groups PCEA was set as; bolus dose: 4 ml, lock-out period: 20 minutes, 4 hour limit: 30 ml. VAS was measured at postoperative 1, 2, 3, 6, 9, 12 and 24th hours. In both groups adequate postoperative analgesia was provided. VAS score was higher in Group BF than Group BM at postoperative 12th hour (p<0.05). One patient in Group BF had unilateral motor block, one patient in Group BM had respiratory depression responding to i.v. naloxan administration. The incidence of pruritis was higher in Group BM than Group BF (p<0.05). Both treatment modalities provided adequate postoperative analgesia, but the risk of respiratory depression with opioid use should be considered.