Pre-emptive efficacy of epidural fentanyl in elective abdominal surgery

This study determines whether epidural fentanyl given before incision decreases the requirements for opioid analgesia postoperatively, compared with the same dose of epidural fentanyl given after the surgery.

Forty patients scheduled to undergo elective abdominal surgery were randomly allocated between two groups according to the time of administered of fentanyl. None of the patients in either group received premedication. Prior to induction of general anaesthesia an epidural catheter was inserted at the L2-3 interspace and flushed with 0.9% NaCl. Patients then received 100 micrograms fentanyl in 10 mL 0.9% NaCl through this catheter either 15 min before awaking at the end of the operation (group I), or else the same dose given at an estimated time of 15 min before the start of surgery (group II). Postoperative analgesia consisted of patient-controlled intravenous fentanyl. The amount of fentanyl used by the patients was noted at 2, 4, 8, 12 and 24 h after surgery. Pain scores and sedation scores were assessed at 0, 2, 4, 8, 12 and 24 h postoperatively.

The consumption of fentanyl was similar in both groups in all studied periods postoperatively. The mean pain score was lower for patients in group I than group II immediately after operation. There were no statistically significant differences between the mean pain scores of groups at 2, 4, 8, 12 and 24 h after operation. Mean sedation scores were similar in both groups at all times postoperatively.

This study showed that the dose of fentanyl administered epidurally prior to surgical incision did not produce any clinically useful pre-emptive analgesic effect.