The audit cycle described by MacEwan (Psychiatric Bulletin, September 2002, 26, 337-339) demonstrates a common error in the practice of electroconvulsive therapy (ECT) administration.

Patients who had brief or absent seizures were re-stimulated with higher charges in the practice described by MacEwan. What has not been taken into account is that duration of convulsions also depends on the individual's response to the muscle relaxant and therefore may not accurately reflect the duration of seizure activity in the brain.

Using motor seizures as a measure of effectiveness of the ECT was an excellent idea in the days of unmodified ECT. It must not be forgotten that muscle relaxants are used precisely to stop the convulsions, and therefore it would be erroneous to use the absence of motor seizures as evidence of inadequate stimulation.

Either electroencephalogram (EEG) monitoring, or if resources do not allow this, use of the simple cuff method would be the best way of monitoring the duration of seizures. The fact the restimulation resulted in induction of adequate seizures in only 25% of cases demonstrates that it may not always be the best course of action.

Lalla & Milroy (Reference Lalla and Milroy1996) have published a comprehensive review of the literature about seizure duration in the practice of ECT. Their inference from the review is that there is a lack of good evidence to support the contention that longer ECT seizures are more efficacious.