Preliminary evaluation of clinical outcome and safety of ketamine as an anesthetic for electroconvulsive therapy in schizophrenia

Objectives. Electroconvulsive therapy (ECT) is an effective and safe option in the treatment of affective disorders and schizophrenia. One parameter known to influence ECT treatment efficacy is the choice of narcotic, and ketamine has emerged as an interesting alternative to conventional anaesthetics like barbiturates since it does not negatively influence seizure threshold. However, due to the potential to provoke dissociative symptoms, ketamine anaesthesia is rather hesitantly used in schizophrenia patients for fear of causing disease exacerbation. Methods. We retrospectively investigated clinical outcome and safety in patients treated with ECT for schizophrenia and receiving ketamine anaesthesia, either exclusively or as switch from another narcotic and compared seizure parameters to a group of ECT-treated schizophrenia patients with thiopental anaesthesia. Results. In none of the six patients undergoing ECT with ketamine did we observe disease exacerbation, and except for one patient, all patients responded or remitted under ECT. A preliminary analysis of seizure parameters shows an association with longer seizures in patients exclusively receiving ketamine. Conclusions. While the small sample size and retrospective character are limitations of our study, our preliminary results nonetheless challenge wide-spread preconceptions about the use of ketamine in schizophrenia patients and encourage further research into the option of using ketamine anaesthesia for ECT.