Electroconvulsive Therapy

Question 1

A 48-year-old female patient is undergoing a course of electroconvulsive therapy (ECT) under general anaesthesia. She has a history of hypertension, for which she takes amlodipine, and asthma, for which she takes salbutamol as required. The procedure is taking place in the mental health building, which is located on a different site to the main hospital.

What are the indications for ECT?

Answer 1

• Drug resistant or life-threatening depression and mania.
• Acute catatonic state.
• Schizophrenia.
• Rarely: Parkinson’s disease, neuroleptic malignant syndrome and
  delirium.

Question 2

How is ECT carried out?

Answer 2

• Induction of an electrical current across the brain via two electrodes (either unilateral or bilateral).
• This gives rise to a tonic-clonic seizure lasting for up to 2 minutes.
• It uses a current of 0.5A, with energy of 30–45 J lasting ~1 second.
• It is administered twice a week for up to 4 weeks.

Question 3

What are your main concerns when anaesthetising this patient?

Answer 3

Patient factors:
* There may be a lack of capacity to consent for the procedure.

• The patient may be a poor historian due to her psychiatric illness.
• There is potential for decreased compliance with treatment for her
  comorbidities.
• The patient may be on medication for her psychiatric condition that
  interacts with the anaesthetic agents used.

Anaesthetic factors:
* A bite block is commonly used when anaesthetising a patient for ECT, which may be challenging if the patient has a difficult airway, poor dental hygiene or active reflux.

• There are concerns associated with remote site anaesthesia including the risks to the patient and staff.

Procedural factors:
* The patient’s comorbidities may affect her suitability for ECT due to the physiological changes that take place during the procedure.

• The physiological systemic changes caused by ECT may lead to further complications in the post-procedural period.

Question 4

What are the contraindications for ECT?

Answer 4

Absolute:
* Patient refusal if he/she has capacity (this is complex and should be discussed closely with their parent team).

Relative:
* Myocardial infarction or cerebrovascular accident during the last 3 months.

• Cardiac failure.
• Glaucoma.
• Untreated deep vein thrombosis.
• Severe osteoporosis or an unstable fracture.
• Raised intracranial pressure.
• Presence of electrical implantable devices (modern devices may be
  safe).

Question 5

What are the specific issues with managing a patient in a remote site?

Answer 5

• The potential lack of appropriate staffing e.g. ODP, senior or emergency help.
• A lack of familiar or appropriate monitoring and equipment.
• The remote site may not have an adequate recovery area.

Question 6

What are the anaesthetic goals when anaesthetising a patient for ECT?

Answer 6

• Induction of anaesthesia with muscle relaxation and a rapid onset and offset.
• Minimise the effects of anaesthesia on the seizure threshold (in particular raising the threshold).
• Decrease the risk of potential complications associated with both ECT and general anaesthesia.

Question 7

What are the main risks and complications associated with ECT?

Answer 7

• Airway: laryngospasm, aspiration, dental damage (minimised with the use of a bite block).
• Cardiovascular: bradycardias/asystole and myocardial infarction due to the sympathetic surge that takes place after the initial parasympathetic response.
• Neurological: memory deficits, confusion, prolonged seizure activity, intracranial haemorrhage.
• Muscular: myalgia, weakness.