The effect of midazolam-thiopental coinduction on recovery in minor surgery

The effects of midazolam-thiopental coinduction on recovery were investigated and compared with thiopental induction.

Fifty patients, ASA 1 or 2, undergoing minor orthopedic surgery, were randomly divided into coinduction and thiopental groups. During preoxygenation, the patients received midazolam 0.1 mg.kg(-1) (coinduction group) or saline (thiopental group) 1 min before induction of anesthesia with thiopental. Isoflurane and nitrous oxide were used to maintain anesthesia. Isoflurane concentration was adjusted to keep blood pressure within +/-20% of the preoperative value. The time to awaken (open eyes, give name and birth-date) and the time to discharge readiness were recorded. Psychomotor tests, including simple light reaction time (SLRT), sedation analogue scale (SAS), and digit span test, were performed pre- and postoperatively.

The induction dose of thiopental was significantly lower in the coinduction group. End-tidal isoflurane concentration during surgery was also lower in the coinduction group. There were no significant differences in awakening times and discharge readiness between the two groups. Although SAS values were lower in the coinduction group than in the thiopental group 8 and 24 h after anesthesia, other test results were similar in both groups. The frequency of nausea and vomiting in the recovery period was lower in the coinduction group.

We conclude that midazolam-thiopental coinduction is a suitable technique when used in conjunction with isoflurane in day-case surgery.