BACKGROUND: Sevoflurane has been widely used for inhalation induction and intubation in children and adults. There are some reports about hemodynamic instability and respiratory effects during inhalation induction. We evaluated the effects of fentanyl, lidocaine, or both on inhalation induction and intubation using sevoflurane without neuromuscular blocking agents.

METHODS: Forty healthy adult female patients, 20 to 60 years old, premedicated with midazolam 3 mg were randomly received iv saline (Group A), lidocaine 1 mg/kg (Group B), fentanyl 1µg/kg (Group C) or both lidocaine 1 mg/kg and fentanyl 1µg/kg (Group D). Anesthesia was induced with 8% sevoflurane inhalation and intubation was done without muscle relaxant. A blind observer recorded the change of blood pressure, heart rate, BIS score, and the time needed for induction and intubation.

RESULTS: The mean times for BIS score below 40 were 87 ± 34 seconds and there were no significant difference among groups. The mean time for loss of self respiration and intubation in group A were significantly longer than those of other groups. The heart rates during induction and intubation of group A were significantly greater than those of other groups. There was no significant difference in blood pressure and side effects during intubation among groups.

CONCLUSIONS: Pre-treatment with fentanyl or lidocaine makes smoother and faster induction and intubation during vital capacity rapid inhalation induction with sevoflurane.