Background: Methohexitone is widely used to provide anaesthesia for patients undergoing electroconvulstive therapy (ECT). Short seizure duration, high blood pressures (BP) and heart rates (HR) are usual in elderly patients. In this study, elderly patients undergoing ECT received low dose methohexitone with remifentanil or methohexitone alone and motor seizure duration, haemodynamic response and recovery time were compared.
Methods: Ten patients, of mean age 74.3 years, were enrolled in this double-blind, randomised crossover trial, receiving a total of 38 ECTs. Each patient was given the following two i.v. regimens in random order: A) methohexitone 0.5 mg kg(-1) combined with remifentanil 1.0 microg kg(-1) and B) methohexitone 0.75 mg kg(-1). Additional methohexitone was given, if needed, until loss of consciousness, and then suxamethonium 1.0 mg kg(-1) for muscular paralysis.
Results: Mean motor seizure duration was significantly longer with methohexitone-remifentanil (37.6 s (SD 12.0)) than with methohexitone alone (27.1 (SD11.5)) (P=0.0009). Recovery time, time to spontaneous breathing, peak postictal changes in BP and HR were similar with both regimens.
Conclusion: A reduced dose of methohexitone combined with remifentanil allows prolonged duration of motor seizures in ECT. We conclude that low dose methohexitone combined with a short-acting opioid is a reasonable alternative for elderly patients undergoing ECT, and for other patients with short seizure duration.