The effect of bupivacaine and morphine on pain and bowel function after colonic surgery

Sixty patients scheduled for colonic surgery were randomly allocated to four groups according to postoperative pain medication: I. Control group, the patients received oxycodone intramuscularly (0.15 mg kg-1) on request. II. Epidural bupivacaine (0.25%) continuously administered by infusion pump, 4-6 ml h-1, for 48 h. III. Epidural morphine, 2-6 mg, at the end of operation and repeated on the first and second postoperative mornings. IV. Epidural morphine, 2-6 mg per die, administered for 48 h continuously by infusion pump. All patients received a balanced anaesthesia with enflurane, fentanyl and vecuronium. Postoperatively, intramuscular oxycodone was given on request. There were no significant differences between the groups in changes in peak flow, spirometry and blood-gas analyses postoperatively. Pain intensity (visual analogue scale) was lower in Groups II and III at 3 h and in Group IV at 24 h compared to the control Group I. All the epidurally treated groups needed less additional analgesics than the control Group I. Postoperatively bowel movements occurred on the second day in Group II (bupivacaine) as compared to the fourth day in all other groups (P less than 0.05).