Background: Treating tachycardia occurring during emergence from general anesthesia is of the highest priority, because it frequently induces myocardial ischemia. Therefore we retrospectively compared the efficacy of esmolol with that of propranolol against such tachycardia.
Methods: Propranolol (n=22) or esmolol (n= 29) was given intravenously when the heart rate was above 100 beats x min(-1) during emergence from anesthesia. The drugs were titrated to decrease the heart rate the level before the induction of anesthesia.
Results: The total dose of propranolol was 0.52+/-0.21 mg (mean+/-SD), which decreased the heart rate significantly from 109.2 +/- 19.0 to 89.2 +/-11.8 beats x min(-1). The total dose of esmolol was 32.8 +/- 16.2 mg, which decreased the heart rate significantly from 110.0+/-13.9 to 84.9+/-10.7 beats x min(-1). The time required for the maximum effect of esmolol (3.2 1.8 min) was significantly shorter than that of propranolol (8.2 +/- 4.9 min). There were no episodes of adverse effects in either group.
Conclusions: Both propranolol and esmolol are equally effective and safe for the treatment of tachycardia during emergence from anesthesia. The time required for the maximum effect of esmolol was shorter than that of propranolol, indicating an advantage of esmolol.