[Postoperative analgesia with epidural methadone in patients operated for hernia of the lumbar disc].

OBJECTIVES

To determine whether the direct application of a single dose of methadone on the dura mater at the end of surgery to repair a lumbar disk hernia provides effective analgesia over the next 24 hours.

PATIENTS AND METHODS

We conducted a randomized double blind study in 40 ASA I patients undergoing elective herniated disk repair under general anesthesia. The sample was divided into two groups (A and B). Group A patients received a solution of methadone in saline solution (5 mg methadone/5 ml saline) applied to the dura before the end of surgery. Group B patients (controls) received only 5 ml of saline. Pain intensity was assessed on a visual analog scale (VAS) during the postoperative period. Also recorded were the observer's impression and the amount of analgesia (ketorolac) consumed through a system providing patient controlled analgesia.

RESULTS

Each group contained 20 patients. Group A patients needed significantly less postoperative analgesia (64.2 +/- 14.3 mg) than group B patients (109.6 +/- 16.5 mg). The VAS scores were significantly lower in group A during the first two hours after surgery and were correlated with the observer's impression. No patients suffered serious complications during the study.

CONCLUSIONS

Topical administration of 5 mg of methadone on the dura mater at the end of herniated lumbar disk repair is an easy, safe and effective technique for providing postoperative analgesia.