a hundred patients scheduled for elective abdominal surgery were randomized to either general anaesthesia ( low-dose fentanyl ) and systemic morphine for postoperative pain or combined general anaesthesia and epidural analgesia with etidocaine 1.5 % intraoperatively ( t4-s5 ) and bupivacaine 0.5 % 5 ml/4 h for 24 h and morphine 4 mg/12 h for 72 h .
C0030201
postoperative pain
C0015120
etidocaine