Inhalational induction with isoflurane: the influence of lidocaine pretreatment.

The effect of intravenous lidocaine in reducing the incidence of complicated induction during a single vital capacity breath technique using isoflurane was studied. Forty patients were randomized into two groups to receive either placebo (group A) or intravenous lidocaine 1.5 mg·kg (group B) just prior to induction. Inhalational induction using 2% isoflurane and 66% nitrous oxide in oxygen was then carried out. Patients pretreated with lidocaine had significantly fewer complications during induction of anesthesia. Modest decreases in blood pressure and heart rate were observed in both groups but were clinically insignificant. Intravenous lidocaine pretreatment significantly reduced the incidence of complications during inhalational induction.