We evaluated the clinical effectiveness of esmolol, an ultra-short-acting, β-adrenergic receptor blocking drug, to control the sinus tachycardia and increase in arterial blood pressure induced by electroconvulsive therapy (ECT). Each of 20 patients, ASA physical status IIII, participated in a double-blind, randomized Latin-Square study involving two matched-pair trials (placebo versus esmolol given as a 500-μg/kg bolus followed by either 300 μg-kg-1-min-1 [high dose], 200 μg-kg_1-min_1 [medium dose], or 100 μg-kg_1-min_1 [low dose] infusion of esmolol) during ECT. Each patient acted as his or her own control (total number of ECT procedures were 160). We administered a 1-min bolus of placebo (normal saline) or esmolol at the rate of 500 μg-kg_1-min_1 followed by either high-, medium-, or low-dose esmolol or placebo for an additional 3 min. We then induced anesthesia with methohexital (1 mg/kg) and succinylcholine (0.5 mg/kg) IV. Ninety seconds after the administration of succinylcholine, the electrical stimulus was applied to induce seizure. The infusion of placebo or esmolol was discontinued 3 min after the electrical stimulus. Significant decreases were found in mean heart rate from minute 3 until minute 7 and in the maximum heart rate. The mean of each patient's maximum heart rate after seizure changed from 147 ± 18 bpm in placebo patients to 112 ± 20 bpm in high-dose esmolol patients; to 121 ± 23 bpm in medium-dose esmolol patients; and to 124 ± 20 bpm in low-dose esmolol patients. Mean arterial blood pressure was significantly lower in the high-dose esmolol patients (100 ± 18 mm Hg) compared with the same patients given placebo (122 ± 25 mm Hg). Finally, the side effect of clinically determined length of seizures decreased in the high- (36 ± 14 s) and medium-dose (34 ± 14 s) esmolol patients as compared with placebo (42 ± 11 s) patients. Low-dose esmolol did not significantly reduce the clinically determined length of seizure (38 ± 11 s). We conclude that the 100-μg-kg-1-min-1 infusion following a 500-μg/kg bolus of esmolol effectively controls the hyperdynamic response to ECT.
Address correspondence to Dr. Howie, Department of Anesthesiology, The Ohio State University Hospitals, Doan Hall, Room N429, 410 West Tenth Avenue, Columbus, OH 43210–1228.
© 1992 International Anesthesia Research Society