Combined spinal-epidural analgesia vs. intermittent bolus epidural analgesia for pain relief after major abdominal surgery. A prospective, randomised, double-blind clinical trial.

BACKGROUND: The primary aim of this study was to compare the efficacy of combined spinal-epidural (CSE) analgesia vs. intermittent bolus epidural analgesia (EA) for pain relief after major abdominal surgery. The secondary aim was to assess the effects of fentanyl addition to subarachnoid morphine and bupivacaine.

METHODS: This was a prospective, randomised, double-blind trial; 160 patients scheduled for major abdominal surgery enrolled. All patients had a thoracic epidural catheter for administration of intra-operative and postoperative analgesia. Patients were assigned to one of four groups: (i) subarachnoid morphine, bupivacaine and fentanyl (MBF group); (ii) morphine and bupivacaine (MB group); (iii) morphine (M group) and (iv) normal saline (EA group). Use of additional intravenous (i.v.) fentanyl and epidural bupivacaine was recorded to measure the need for supplemental intra-operative analgesia. Pain at rest, with movement, and with cough (measured with a visual analogue scale), additional analgesia requests, and side effects were recorded over 72 h postoperatively.

RESULTS: Compared with the EA group, the MBF group had significantly reduced pain with cough and lower analgesia requirements during the first 24 h (p<0.001) and after EA discontinuation (p=0.041). The MBF group required less intra-operative epidural bupivacaine compared with all other groups (p<0.001), and less intra-operative i.v. fentanyl compared with group M (p<0.001).

CONCLUSIONS: Combined spinal-epidural improved intra-operative analgesia and reduced pain with cough in the immediate postoperative period. The addition of fentanyl to subarachnoid morphine and bupivacaine decreased the need for additional i.v. fentanyl and epidural bupivacaine analgesia.