Effect of Cardioselective β‐Blockers on the Heart Rate and Arterial Pressure Responses to Laryngoscopy

Abstract
The effects of the cardioselective beta-blockers practolol (Eraldin, ICI) and metoprolol (Seloken, Hässle) were studied during microlaryngoscopy. I. v. practolol (0.4 mg/kg before and 0.2 mg/kg during anaesthesia) did not protect against increases in arterial pressure, although heart rate was reduced. Oral metoprolol (0.2 g for 4 days) reduced the level of arterial pressure both before and during anaesthesia. Variations in arterial pressure were not attenuated. Very low levels of arterial pressure were seen, and variations in arterial pressures were attenuated when metoprolol was combined with fentanyl.