The timing of electroconvulsive therapy and bispectral index after anesthesia induction using different drugs does not affect seizure duration

Abstract

Study objective To determine the association between bispectral index (BIS) and seizure duration obtained by electroconvulsive therapy (ECT) administered sooner or later after anesthetic induction. Design Prospective, randomized, crossover study. Setting University-affiliated medical center. Patients Nine ASA physical status I, II, and III patients undergoing a total of 31 ECTs. Interventions ECT was administered soon (<210 sec) or later (between 210 sec and 360 sec) after anesthetic induction. In each individual patient, drug regimens and ECT machine settings were identical. Measurements BIS immediately before the start of the ECT and the duration of the EEG seizure were recorded, as well as the time period between loss of consciousness and ECT administration. Main results There was no relationship between BIS level and seizure duration. Moreover, seizure duration was not dependent on the time of ECT administration in the time window between one and 6 minutes after loss of consciousness. Conclusion The hypnotic drug effect measured by the BIS is not correlated to the seizure duration obtained by ECT.