Background: Methohexitone has been the most widely used anaesthetic for electroconvulsive therapy (ECT). However, recent scarcity and erratic availability has led to use of other anaesthetics with differing effects upon ECT. We compared treatment parameters and response to ECT in patients anaesthetised with different anaesthetics in a routine clinical setting.
Methods: This was a naturalistic retrospective casenote analysis of 81 consecutive courses of ECT (total 659 treatments) for major depression.
Results: Three anaesthetics were compared: methohexitone (n=34), propofol (n=13) and etomidate (n=34). Mean seizure duration was lowest (p<0.0001) for propofol. However, mean stimulus charge was highest in the propofol group (p<0.0001) who required a greater increase in stimulus charge during the course of treatment and also experienced a greater proportion of failed seizures (</=15 s on EEG). Despite differing effects upon treatment parameters, choice of anaesthetic did not appear to significantly affect therapeutic response to ECT. Use of propofol may be associated with longer treatment course that could result in extra cost.
Limitations: This was a retrospective casenote study, in which patients were not randomised to anaesthetic and standardised outcome measures were not used. The small sample size in the propofol group may have reduced the power of the study to demonstrate other differences between propofol and the other anaesthetic groups. A formal economic analysis was not performed.
Conclusion: Individual anaesthetics differentially influence seizure duration and stimulus charge but final response to ECT appears not to be adversely affected.