Effect of labetalol or lidocaine on the hemodynamic response to intubation: a controlled randomized double-blind study.

Labetalol, a combined alpha 1- and nonselective beta-adrenergic blocking drug, was compared to lidocaine or saline to minimize the hypertensive and tachycardic response to intubation in a controlled randomized double-blind study in patients undergoing surgical procedures under general anesthesia. Forty adult patients were divided into four groups of 10 each: placebo (saline), lidocaine 100 mg, labetalol 5 mg, or labetalol 10 mg. The double-blind preparation was administered as an IV bolus just prior to induction and 2 min before the stimulus of laryngoscopy and intubation. Heart rate and blood pressure were measured at 1-min intervals for 2 min prior to induction of anesthesia and through 6 min following induction of anesthesia. Labetalol 10 mg prevented a rise in heart rate after intubation compared to patients who received placebo, lidocaine 100 mg, or labetalol 5 mg. The hypertensive response to intubation was similar in all four groups. Labetalol 10 mg IV just prior to induction of anesthesia is a safe and cost-effective means of preventing tachycardia but not hypertension in response to laryngoscopy and intubation.