Total Charge Required to Induce a Seizure in a Retrospective Cohort of Patients Undergoing Dose Titration of Right Unilateral Ultrabrief Pulse Electroconvulsive Therapy

Objectives: The use of ultrabrief pulse (UBP) stimuli and individual seizure threshold determination have been proposed as ways of minimizing the cognitive side effects of electroconvulsive therapy (ECT), but large samples of patients receiving UBP ECT are lacking. This study reports a retrospective cohort of patients receiving an index course of right unilateral UBP ECT and characterizes the amount of charge required to induce a seizure. Methods: A single-center retrospective chart review was conducted of adult patients receiving a first lifetime course of ECT using an UBP titration from 2005 to 2017. Results: There were 2328 patients that received a dose titration during the study period, with a mean dose of 21.82 +/- 21.61 mC applied to induce a seizure. During the early part of the study period, a mean dose of 18.73 +/- 8.99 mC was used, with 28% of patients seizing at a dose of less than 19.2 mC. In the later period, the initial step of dose titration was standardized at 19.2 mC, yielding a mean initial dose to induce a seizure of 22.72 +/- 24.00 mC. Conclusions: Mean seizure thresholds may be lower than reported in previous studies, and a significant proportion of patients may have a seizure threshold lower than the first step of many existing dose titration protocols.