Oxygen supplementation during electroconvulsive therapy

Abstract

The effects of ventilation with 30% and 100% oxygen were investigated on the circulatory and electrocardiographic response to electroconvul-sive therapy (ECT) in 12 patients during 40 treatments. Administration of 30% oxygen resulted in a 25% decrease in seizure duration compared with 100% oxygen (P < 0.0125). Hypoxaemia, defined as SaO2 less than 90%, occurred during five of 20 treatments with 30% oxygen and during two of 20 treatments with 100% oxygen (ns), and was associated invariably with loss of airway control. Heart rate, arterial pressure, and the incidence of cardiac arrhythmias were not affected significantly by oxygen supplementation. Inspired oxygen concentration has a significant effect on seizure activity and should be of a consistent value if a reproducible seizure is to be produced during ECT. Breathing 100% oxygen does not appear to affect adversely the cardiovascular response to ECT. However, arterial hypoxaemia may develop rapidly during or after the seizure, regardless of oxygen supplementation, if adequate control of airway and ventilation is not maintained. © 1988 British Journal of Anaesthesia.