Treatment of hypertension following endotracheal intubation. A study comparing the efficacy of labetalol, practolol and placebo.

Labetalol, a new adrenergic receptor antagonist, has both alpha- and beta-blocking properties. Intravenous labetalol (0.25 and 0.5 mg/kg), practolol (0.4 mg/kg) and saline (1 ml), injected prior to anaesthesia, were compared with respect to their effect on the haemodynamic consequences of direct laryngoscopy followed by the passage of an endotracheal tube. When compared with intravenous saline injection, both labetalol and practolol obtunded the tachycardia induced by endotracheal intubation. The higher dose of labetalol was more effective in reducing the hypertensive response than the lower dose of practolol. However, none of the regimens completely abolished the adverse haemodynamic consequences of laryngotracheal manipulations.