Regional Cerebral Oxygen Saturation During Electroconvulsive Therapy

Abstract

Electroconvulsive therapy (ECT) increases neuronal energy consumption and alters systemic hemodynamics.We examined the effects of ECT on regional cerebral oxygen saturation (rSO2) using a near-infrared spectrophotometer. Heart rate (HR), mean arterial blood pressure (MAP), and rSO2 were continuously monitored throughout ECT under general anesthesia in 43 patients. In all subjects, rSO2 changed in a consistent pattern during ECT, initially decreasing (-9.4% +/- 0.9%) just after application of the electrical current and subsequent increasing (8.7% +/- 0.9%) beyond the pre-ECT value. A close correlation was demonstrated between the increase in rSO2 and the mean blood pressure after the electrical shock (r2 = 0.832, P < 0.0001). We conclude that ECT initially may increase cerebral metabolic rate of oxygen more than cerebral blood flow and that rapidly increasing blood pressure transiently may overwhelm cerebral pressure autoregulation. (Anesth Analg 1996;83:726-30)