Ketamine as the anaesthetic for electroconvulsive therapy: the KANECT randomised controlled trial

Abstract

BackgroundKetamine has recently become an agent of interest as an acute treatment for severe depression and as the anaesthetic for electroconvulsive therapy (ECT). Subanaesthetic doses result in an acute reduction in depression severity while evidence is equivocal for this antidepressant effect with anaesthetic or adjuvant doses. Recent systematic reviews call for high-quality evidence from further randomised controlled trials (RCTs).AimsTo establish if ketamine as the anaesthetic for ECT results in fewer ECT treatments, improvements in depression severity ratings and less memory impairment than the standard anaesthetic.MethodDouble-blind, parallel-design, RCT of intravenous ketamine (up to 2 mg/kg) with an active comparator, intravenous propofol (up to 2.5 mg/kg), as the anaesthetic for ECT in patients receiving ECT for major depression on an informal basis. (Trial registration: European Clinical Trials Database (EudraCT): 2011-000396-14 and clinicalTrials.gov: NCT01306760)ResultsNo significant differences were found on any outcome measure during, at the end of or 1 month following the ECT course.ConclusionsKetamine as an anaesthetic does not enhance the efficacy of ECT.

Fig. 1

CONSORT flow diagram showing patient eligibility and inclusion in the trial. *One patient is the same patient; ^†Patient refused Cambridge Automated Neuropsychological Test Battery Spatial Recognition Memory task (CANTAB SRM) (n = 1); ^‡Completed over telephone so no CANTAB (n = 1). ECT, electroconvulsive therapy.

Fig. 2

Mean scores on the dependent measures across time (pre-electroconvulsive therapy (ECT), post-final ECT and 1-month post-ECT) by anaesthetic group (treatment effects analysis). (a) Group differences in Hamilton Rating Scale for Depression (HRSD) ratings across follow-up, (b) group differences in Montgomery–Åsberg Depression Rating Scale (MADRS) ratings across follow-up, (c) group differences in Cambridge Automated Neuropsychological Test Battery Spatial Recognition Memory task (CANTAB SRM) scores across follow-up. Error bars are the standard error of the mean.