Ketamine Anesthesia in Electroconvulsive Therapy

A Randomized Comparison of Ketamine and Methohexital Anesthesia for Electroconvulsive Therapy (ECT) in Depression

Does the use of ketamine as the anesthetic medication in electroconvulsive therapy (ECT) accelerate the antidepressant effect of ECT? The study hypothesis was that depressed subjects receiving ECT with ketamine as the anesthetic agent would demonstrate a faster rate of improvement, defined as lower depression ratings after the second ECT than depressed patients receiving ECT with the usual anesthetic agent.

There are several drugs available to induce anesthesia for electroconvulsive therapy (ECT), a psychiatric treatment for major depressive illness. The most commonly utilized of these include methohexital, thiopental, etomidate, and propofol. Recently, there has been interest in the use of ketamine in sub-anesthetic doses to treat major depressive illness. In this randomized, blinded trial, depressed subjects scheduled to be treated with ECT were anesthetized with either ketamine or methohexital at doses of approximately 1.0 mg/kg for each drug. Patients received the same drug for up to six of their ECT treatments. Outcome measures included assessments of depressive severity, cognition, post-anesthesia side effects, and hemodynamics. Subjects were to be followed with as long as they were receiving inpatient ECT treatments. The number of treatments was determined entirely by their primary psychiatric team, also blind to anesthetic, as per usual care. In other words, this study did not determine when to terminate the ECT course.

Subjects were dosed with approximately 1.0 mg/kg, using ketamine as anesthetic prior to electroconvulsive therapy (ECT).

Subjects were dosed with approximately 1.0 mg/kg, using methohexital as anesthetic prior to electroconvulsive therapy.

The HADS is a fourteen item scale. Seven of the items relate to anxiety and seven relate to depression. Each item on the questionnaire is scored from 0-3 and this means that a person can score between 0 (no symptoms) and 42 (severe symptoms) for either anxiety or depression. The questionnaire was administered to the subjects prior to the first treatment, the morning of the third treatment, the morning of the fifth treatment, and the morning of the seventh treatment. For subjects whose treatment series ws cancelled prior to a scheduled next administration of the rating scale, every effort was made to administer them 2 days after the last treatment. Means are reported overall across all treatments; p-values also take into account variability across treatments and within subject.

The PHQ-9 is the nine item depression scale of the Patient Health Questionnaire. The PHQ-9 is based directly on the diagnostic criteria for major depressive disorder in the Diagnostic and Statistical Manual Fourth Edition (DSM-IV). Each item on the questionnaire is scored from 0-3 and this means that a person can score between 0 (no symptoms) and 27 (severe symptoms) for depression. The questionnaire was administered to the subjects prior to the first treatment, the morning of the third treatment, the morning of the fifth treatment, and the morning of the seventh treatment. For subjects whos treatment series ws cancelled prior to a scheduled next administration of the rating scale, every effort was mde to administer them 2 days after the last treatment. Means are reported overall across all treatments; p-values also take into account variability across treatments and within subject.

Post anesthesia recovery side effects were assessed at the time of discharge from recovery with five patient self-report items: nausea, headache, myalgia, visual disturbance, and confusion. These were rated by the patients on a four point scale (0, 1, 2, 3) - absent, mild, moderate, severe. This means that for each item a subject could score between 0 (no symptoms) and 3 (severe symptoms). Also, degree of recovery room agitation was rated by the nurse on a similar four point scale.

Time of discharge from recovery after ECT for each treatment, approximately 30 minutes after the end of the seizure

Inclusion criteria: Diagnosis of depression, either unipolar or bipolar Subjects receiving ECT at the Mayo Clinic Exclusion criteria: Subjects not giving their own consent to ECT Subjects with schizophrenia, schizoaffective disorder, or dementia Subjects diagnosed with a major neurological disorder such as epilepsy, Parkinson disease, multiple sclerosis, or a neurodegenerative dementia.