The analgesic effect of nefopam combined with low dose remifentanil in patients undergoing middle ear surgery under desflurane anesthesia: a randomized controlled trial

BACKGROUND We investigated the effects of the combined administration of nefopam, a N-methyl-D-aspartate receptor antagonist and low dose remifentanil, on early postoperative pain and analgesic requirement. METHODS Fifty patients scheduled to undergo mastoidectomy and tympanoplasty were randomized to be given either nefopam 40 mg mixed with normal saline 100 ml (Group N) or an equal amount of normal saline (Group C) before anesthesia induction. Anesthesia was maintained with 5-6 vol% desflurane and remifentanil 0.05-0.15 µg/kg/min during the surgery. Postoperative pain was controlled by titration of ketorolac in the postanesthesia care unit (PACU) and ward. We evaluated the intraoperative remifentanil dose, recovery profiles, ketorolac demand in the PACU and ward, numeric rating scale (NRS) for pain at time intervals of every 10 min for 1 h in the PACU, 6, 12, 18 and 24 h in a ward, as well as the time to first analgesic requirement in the PACU and ward. RESULTS Ketorolac demand and NRS in the PACU were significantly lower in Group N than Group C (P = 0.002, P = 0.005, respectively). The time to first analgesic requirement in the PACU in Group N were significantly longer than Group C (P = 0.046). There were no significant differences in intraoperative remifentanil dose, ketorolac demand, NRS, and the time to first analgesic requirement in the ward between the groups. CONCLUSIONS Nefopam administration combined with low dose remifentanil infusion reduces pain and analgesic consumption during the immediate postoperative period in patients undergoing middle ear surgery under desflurane anesthesia.