A survey of methohexitone use by anesthetists in the clinical practice of ECT in Edinburgh

Anesthetic care for electroconvulsive therapy

Counselling and medication are often thought of as the only interventions for psychiatric disorders, but electroconvulsive therapy (ECT) has also been applied in clinical practice for over 80 years. ECT refers to the application of an electric stimulus through the patient’s scalp to treat psychiatric disorders such as treatment-resistant depression, catatonia, and schizophrenia. It is a safe, effective, and evidence-based therapy performed under general anesthesia with muscle relaxation. An appropriate level of anesthesia is essential for safe and successful ECT; however, little is known about this because of the limited interest from anesthesiologists. As the incidence of ECT increases, more anesthesiologists will be required to better understand the physiological changes, complications, and pharmacological actions of anesthetics and adjuvant drugs. Therefore, this review focuses on the fundamental physiological changes, management, and pharmacological actions associated with various drugs, such as anesthetics and neuromuscular blocking agents, as well as the comorbidities, indications, contraindications, and complications of using these agents as part of an ECT procedure through a literature review and our own experiences.

The Historical Struggles of Modified Electroconvulsive Therapy: How Anesthesia Came to the Rescue

The complicated history of modified electroconvulsive therapy (ECT) started back before anesthesia was incorporated when unmodified electroconvulsive therapy was not considered humane. When anesthesiologists started working with psychiatrists, ECT gradually regained acceptance by decreasing the obstacles inherent to this therapy despite the complexities of the anesthetics. However, the sociopolitical and medicolegal factors negatively impacted the use of modified ECT leading to a period of time when it was banned from use in the United States. Fortunately, as advances in anesthesia and technology continued to develop, anesthesiologists helped ECT regain widespread usage improving the safety profile, cost effectiveness, quicker onset of seizures, and ease of control despite its stained past. This allowed more accessibility, especially for high-risk medical patients, to a relatively safe and effective treatment for psychiatric diseases.

[Anesthesia for electroconvulsive therapy]

Electroconvulsive therapy is a well-established form of treatment for a broad spectrum of severe psychiatric disorders. The treatment, in which a generalized epileptic seizure is provoked by electrical stimulation of the brain, is performed with the patient under anesthesia and muscle relaxation. Therefore, sufficient knowledge of the physiological and pharmacological characteristics is an essential requirement for safe anesthesia. The following review is intended to provide some new aspects of the procedure and management of anesthesia.

Effects of remifentanil on convulsion duration and hemodynamic responses during electroconvulsive therapy: a double-blind, randomized clinical trial

BACKGROUND

Among the drugs used for the induction of anesthesia for electroconvulsive therapy (ECT), thiopental induces a greater degree of cardiovascular alteration than other agents. Remifentanil has been found to reduce blood pressure and heart rate when administered as an adjuvant during general anesthesia, with unknown effects on the duration of motor or electroencephalographic seizure activity during ECT. The purpose of this prospective, randomized, double-blind, placebo-controlled, crossover study was to evaluate the effects of supplementing thiopental anesthesia with remifentanil on convulsion duration and cardiovascular response during ECT.

METHODS

Twenty-four American Society of Anesthesiologists I and II patients receiving 6 sessions of ECT were randomly allocated to 2 groups. All patients were premedicated with atropine (0.4 mg, intravenously), then anesthesia was induced by thiopental (1.0 mg/kg), succinylcholine (0.5 mg/kg), and remifentanil (1.0 microg/kg) in the case group or normal saline (3 mL) in the control group in a crossover format. Stimulus amplitude for applying ECT was kept constant during the sessions of treatment in the course of study for each patient. Hemodynamic parameters, convulsion duration, and recovery parameters were recorded. Statistical analysis was done using paired t tests.

RESULTS

There was no statistically significant difference between the groups regarding convulsion duration, recovery times to eye opening, obeying specific commands, and walking without help. Remifentanil significantly attenuated the increase in heart rate and arterial blood pressure (P < 0.05).

CONCLUSIONS

Remifentanil (1 microg/kg) administered before thiopental (1 mg/kg) has no adverse effect on the duration of ECT-induced convulsion and recovery time, but it can attenuate the increase in heart rate and arterial blood pressure.

Anästhesiologische Aspekte bei Elektrokrampftherapie

Electroconvulsive therapy (ECT) is used in the therapy of severe psychiatric disorders. The treatment, in which a generalized epileptic seizure is provoked by electrical stimulation of the brain, is performed under anaesthesia and muscle relaxation. Considering careful previous clinical examination and anaesthesiological and internal contraindications, ECT is a safe form of treatment. The following review is intended to familiarize with ECT and to provide advice for the anaesthesiological management.

Bispectral index-controlled anaesthesia for electroconvulsive therapy*

BACKGROUND

The suggested induction dose of methohexital for electroconvulsive therapy (ECT) varies widely influencing efficacy of ECT and safety of anaesthesia. Bispectral index (BIS), a monitor of consciousness, may be useful to assure adequate hypnosis with optimized methohexital dose.

METHODS

Patients with medically resistant major depression (ICD10), scheduled for multiple ECT's, were studied. Depth of anaesthesia was BIS controlled. ECT was not performed until BIS dropped below 50. Initially anaesthesia was induced with methohexital 1.0 mg kg(-1), and stepwise reduced by 0.1 mg kg(-1) during consecutive treatments. If BIS did not drop below 50, the methohexital was supplemented by further boluses of 0.5 mg kg(-1), until the desired level of hypnosis was reached. The adequacy of the anaesthetic recommendation for methohexital (1.0-1.5 mg kg(-1)) as well as the psychiatric recommendation (0.75-1 mg kg(-1)) was investigated.

RESULTS

One-hundred and nine ECT's in 14 patients were studied. The recommended anaesthetic dose (1.0-1.5 mg kg(-1)) was inadequate in 40% of the treatments, with 12% exceeding 1.5 mg kg(-1), and 28% below 1.0 mg kg(-1). Psychiatric recommendation (0.75-1.0 mg kg(-1)) was inadequate in 49%, with 39% exceeding 1.0 mg kg(-1) and 10% undershooting at 0.75 mg kg(-1).

CONCLUSIONS

Methohexital for ECT showed a great variability, exceeding as well as undershooting the dosage recommendations widely. BIS monitoring may be useful to secure adequate hypnosis during muscle relaxation and treatment and may optimize ECT efficacy.

The comparative effects of sevoflurane and methohexital for electroconvulsive therapy

The standard anesthetic agent for electroconvulsive therapy (ECT) has been methohexital. We compared sevoflurane, a short-acting halogenated anesthetic, to methohexital for induction in ECT. Twelve subjects received sevoflurane or methohexital on alternating treatment days. Seizure duration, time to administering ECT, emergence and recovery, as well as several hemodynamic measures were recorded. A total of 69 treatments were analyzed. When sevoflurane was used, seizure durations recorded by observation and by EEG, were shorter by 10 and 23 seconds, respectively. With sevoflurane, seizure duration remained, however, within a clinically acceptable range. Methohexital allowed faster administration of ECT and discharge from the recovery room (3.8 vs. 6.2 minutes and 40.8 vs. 47.0 minutes, respectively). No difference in the post-ECT hemodynamic changes was found between the two treatments. We conclude that, when indicated, sevoflurane could provide a suitable alternative treatment option to methohexital, but some limitations, including shortened seizure duration and potential side effects, should be kept in mind.