Rapid development of acute opioid tolerance and hyperalgesia is well established in animal studies and is more likely to occur with large doses of short-acting drugs. Several experimental and clinical studies of varied design that have been conducted in humans comparing remifentanil with other routinely used anesthetics or placebo preparations have produced conflicting results. The aim of this study was to investigate whether remifentanil had any impact on postoperative pain after gynecologic surgery.

Sixty patients undergoing gynecological surgery were randomly allocated into three groups (each n=20): N group with normal saline, L group with target-controlled infusion (TCI) of 1 ng/ml remifentanil, and H group with TCI of 3 ng/ml remifentanil. All patients were anesthetized with sevoflurane to maintain mean arterial pressure within 20% of basal values. Thirty minutes before the end of surgery, patients received morphine sulfate through a patient-controlled infusion device. Pain scores, sedation scores, and analgesic requirements were recorded for 48 hours postoperatively.

The mean remifentanil infusion dose of the H group was significantly higher than that of the L group. The VAS scores of the L and H groups were significantly higher than those of the N group only at the postanesthetic care unit and not at the ward.

Intraoperative use of remifentanil with sevoflurane may be related to increased postoperative pain during early postanesthetic period. Provision for effective preventive and therapeutic management strategies in case of intraoperative remifentanil use may be reasonable.