Airway intervention is known to activate stress response and release catecholamines resulting in severe hemodynamic instability. Various techniques which are recommended to prevent the stress response include increasing the depth of anesthesia, improving surgical procedures and the use of various pharmacological agents. Esmolol blocks the action of the endogenous catecholamines, we plan low dose esmolol infusion decrease stress response and hemodynamic fluctuation during airway intervention.~46 patients scheduled airway intervention under general anesthesia were randomly divided into esmolol group and control group. esmolol 50μg/kg/min or saline 50μg/kg/min were iv administered before Operation beginning. If HR（heart rate）is greater than 90 beats/min, esmolol or saline 50μg/kg/min is added each time, with interval more than 5 min and the peak value is 200 μg/kg/min. If the heart rate is lower than 60 times/minute, Stop medication. Plasma level of Norepinephrine, epinephrine, and cortisol before induction of anesthesia and 30 minutes after beginning of operation were determined by high-performance liquid chromatography. Perioperative hemodynamics changes, extubation time, incidence of severe sinus bradycardia and bronchospasm were recorded.
The goal of this clinical trial is to observe the effect of low dose continuous infusion of esmolol on perioperative stress response in patients undergoing airway intervention .