David A. Zvara

Esmolol reduces autonomic hypersensitivity and length of seizures induced by electroconvulsive therapy

We evaluated the clinical effectiveness of esmolol, an ultra-short-acting, β1-adrenergic receptor blocking drug, to control the sinus tachycardia and increase in arterial blood pressures induced by electroconvulsive therapy (ECT). Each of 20 patients, ASA physical status I-III, participated in a double-blind, randomized study involving four match-pair trials (placebo versus esmolol) during ECT. Each patient acted as his or her own control (total number of ECT procedures, 160). We administered a 4-min infusion of either placebo or esmolol at the rate of 500 μg · kg−1 · min−1. We then induced anesthesia with methohexital and succinylcholine. After administration of electrical stimulation for ECT, the rate of infusion decreased to 300 μg · kg−1 · min−1 for three additional minutes and was then discontinued. Statistically significant reductions in mean heart rate from minute 2 until minute 15 and in maximum heart rate (the mean of each patients maximum heart rate after seizure changed from 152 ± 23 to 115 ± 24 beats/min) occurred in patients given esmolol. During and immediately after infusion, arterial blood pressure also decreased. Finally, the length of seizures decreased, as manifested clinically from 48 ± 18 to 39 ± 14 s and on electroencephalogram from 86 ± 41 to 67 ± 28 s. We conclude that esmolol effectively controls the hyperdynamic response to ECT and reduces the length of seizures. The significance of the latter to the overall effectiveness of ECT is not known.