Intra-operative epidural morphine, fentanyl, and droperidol for control of pain after spinal surgery. A prospective, randomized, placebo-controlled, and double-blind trial.

The present study was conducted to investigate the analgesic effects of intra-operatively administered epidural morphine in patients undergoing surgery for lumbar disc disease. Three treatment groups were constituted: one with 5.0 mg morphine and 2.5 mg dehydrobenzperidol (DHB) in 10 ml physiological saline, one with 5.0 mg morphine and 0.1 mg fentanyl in the same amount of saline, and one placebo group with saline only. The test solution was injected epidurally via catheter after haemostasis and before closure of the wound. Sixty eight patients were randomly assigned to each of the three groups and subjected to a double-blind evaluation. In the morphine/fentanyl and morphine/droperidol groups, significantly better analgesia was found as compared to the placebo group. No significant difference was found between the morphine/fentanyl and morphine/droperidol groups considering side effects of therapy, as well as duration and quality of analgesia. The side effects in the treatment groups were only slight and not significantly different from the placebo group. It was shown that additional epidural fentanyl offers no significant improvement of postoperative analgesia. No significant reduction of adverse effects could be found in the morphine/droperidol group compared to the morphine/fentanyl group. In conclusion, the intra-operative epidural application of morphine is a safe, effective and simple method for achieving sufficient analgesia in the first 24 hours after lumbar spinal surgery for disc disease.