Electroconvulsive Therapy [Part 3] ECT Procedure
Electroconvulsive therapy (ECT) is a form of psychiatric treatment that involves inducing seizures with the use of electrical stimulation while an individual is under general anesthesia. ECT is primarily indicated in people who require a rapid treatment response due to the severity of their condition such as violent patients or risk for suicide or catatonia.
While the patient is under full general anesthesia, a muscle relaxant is given and electrodes are applied to the scalp. A brief electrical stimulus is delivered. The effective stimuli produce a mild seizure which changes the activity of the brain. The brain stimulation is accompanied by mild muscle contractions usually lasting less than one minute.
The electrical stimulus can be delivered in one of three ways; right unilateral, bi-frontal or bi-lateral. Most patients begin treatments with a right unilateral stimulus. If, after several treatments, the patient is not improving, the stimulus can be changed. The benefit of changing to bi-frontal or bi-lateral is a faster improvement in mood. The risk is an increased chance of memory loss. The decision to change the electrical stimulus is made by the patient and the psychiatrist.
ECT requires multiple treatments. The treatments are divided into two series of treatments, acute and maintenance. During the acute series, ECT treatments are given three times a week for a total of 6 to 12 treatments for the majority of patients. Prior to each treatment, the patient is evaluated for improvement.
Before beginning a series of ECT treatments, a patient should receive a thorough psychiatric assessment, a medical examination and sometimes a basic blood test and an electrocardiogram (ECG) to check heart health.
Informed consent is another important part of the process. A patient must provide written informed consent before ECT is administered. In situations where a person is too ill to make decisions for him or herself, the consent process is governed by state law (for example, a court-appointed guardian).
Patients and their families should discuss all options for treatment with the psychiatrist before making a specific treatment decision. They should be provided with sufficient information to fully understand the procedure and the potential benefits, risks, and side effects of each treatment option before providing written consent.
A patient typically receives ECT two or three times a week for a total of six to 12 treatments, depending on the severity of symptoms and how quickly the symptoms respond to the treatment.
At the time of each treatment a patient is given general anesthesia and a muscle relaxant and electrodes are attached to the scalp at precise locations. The patient's brain is stimulated with a brief controlled series of electrical pulses. This causes a seizure within the brain that lasts for approximately a minute. The patient is asleep for the procedure and awakens after 5-10 minutes, much as from minor surgery.
Sinusoidal wave Vs Brief Pulse ECT
Current flows almost continuously with the sinusoidal waveform. As a result, far more electrical charge is delivered than is necessary to trigger the seizure. The extra charge may not increase efficacy but does increase the cognitive adverse effects of the treatment. In contrast, with constant current, brief-pulse ECT devices, current is delivered in short pulses. The seizure which is triggered can be as effective as that with sinusoidal wave ECT, and is associated with less cognitive adverse effects.
According to Ohm’s law, the current in a circuit is inversely proportional to the resistance. As resistance varies from patient to patient, at the constant voltage the current in the circuit and hence the electrical charge delivered during ECT will also vary from patient to patient.
Relationship between electrical current and therapeutic effects
Higher electrical doses are associated with a greater proportion of responders in patients who receive right unilateral ECT and also it is associated with faster response to ECT. However, higher electrical doses are associated with greater cognitive adverse effects.
The introduction of convulsive therapy to psychiatry and changes in seizure induction from chemical to electrical are outlined. The place of ECT in contemporary psychiatry, particularly its most important clinical indications, is briefly discussed. Negative media representation and historical misuse are likely to have contributed to negative professional and public attitudes towards ECT