The objective of this study was to determine if there is a dose-dependent relation between etomidate and motor and electroencephalogram (EEG) seizure duration in electroconvulsive therapy (ECT).
Seventy-four patients who received at least 3 ECT treatments with etomidate as an anesthetic were included. The association between seizure duration established by EEG and the cuff method, and etomidate dose (in mg/kg) was assessed retrospectively within individual patients, using mixed-effects model analysis with random intercept and random slope. Generalized estimating equation analysis was used to assess whether chances of reaching an adequate seizure depended on dose.
A small negative association between dose of etomidate and motor and EEG seizure duration was found with a maximum correlation of −0.21. This correlation is considered weak and therefore lacks clinical significance. Higher doses of etomidate decreased the chances of an adequate seizure with an odds ratio of 0.68 per 0.1-mg/kg increase in etomidate (95% confidence interval, 0.52 – 0.90, P-value: 0.007). With a maximum dose of 0.3 mg/kg, 94.1% of the seizures were adequate (95% confidence interval, 91.0–96.2).
Our data confirm that there is no clinically relevant dose-dependent relation between etomidate and seizure duration in ECT when etomidate is administered as advised in current international guidelines.
From the *Departments of Old Age Psychiatry (GGZ in Geest VU University Medical Center), †Epidemiology and Biostatistics, and ‡Anesthesiology, VU University Medical Center, Amsterdam, the Netherlands.
Received for publication September 2, 2012; accepted October 22, 2012.
Reprints: Annemieke Dols, MD, PhD, Department of Old Age Psychiatry, GGZ in Geest, Valeriusplein 14, 1075 BH Amsterdam, the Netherlands (e-mail: a. firstname.lastname@example.org).
This study has no sources of support that require acknowledgment.
The authors have no conflicts of interest to declare.