Nitrous oxide (N₂O) may increase middle ear pressure during anesthesia, resulting in the displacement of tympanic membrane graft for tympanoplasty. This study was performed to assess the feasibility of remifentanil instead of N₂O by comparing hemodynamics, recovery profiles, postoperative analgesia and complications during isoflurane-based anesthesia for tympanoplasty.

Forty patientsundergoing tympanoplasty were randomly allocated to N₂O-isoflurane anesthesia (group N) and remifentanil-isoflurane anesthesia (group R). In group N, N₂O was used from induction to 15-30 minutes prior to grafting tympanic membrane and then N₂O was changed to air. In group R, remifentanil was infused to the end of surgery. Isoflurane was used in both groups. We compared mean arterial pressure (MAP), heart rate (HR) and recovery times between groups during perioperative period. Postoperative pain, analgesic demand and nausea/vomiting during postoperative period were also compared.

MAP and HR were significantly higher in group N than group R at 1 minute, 5 minutes after intubation, skin incision and closure. Hypertensive and tachycardiac events were also more frequent in group N during operation. Time to spontaneous respiration was significantly shorter in group N, but times to eye opening, extubation and recovery of orientation were significantly shorter in group R. There were no significant differences in pain scores, analgesic demand and nausea/vomiting during postoperative period.

Remifentanil can provide more stable hemodynamic status and faster emergence than N₂O without significant increase of pain level, analgesic demand and adverse effects in isoflurane-based anesthesia for tympanoplasty.