ECT

Question 0

Theories about mechanism of action?

Answer 0

Unknown.

1) increase in release of neurotransmitters I.e. Dopamine, serotonin
2) stimulates release of hormones via the hypothalamus/pituitary gland I.e. Prolactin, TSH, ACTH, endorphins
3) anticonvulsant properties

Question 1

What is ECT?

Answer 1

Involves intentional induction of a generalized (impairs consciousness) seizure under general anaesthetic which had been found to have a therapeutic effect.

Question 2

How many sessions, what happens?

Answer 2

First session - dose titration
- determine the level of activity of seizure based on EEG

Usually requires 3 sessions/week.
Subsequent session frequency based on clinical improvement

Question 3

What is the difference in electrode placement?

Answer 3

Unilateral - less effective, less side effects, non-dominant hemisphere preferably to minimise cognitive side effects

Bilateral: more effective, more side effects (esp. Cognitive)

Question 4

What is involved in the actual procedure?

Answer 4

General anaesthetic: propofol (anaesthetic induction agent with sedating features) and succinylmethonium (muscle relaxant). Check eye reflex if present?

EEG, EMG + ECG cont monitoring

Adequacy of seizure determine by EEG tracing: recruitment phase, poly spike patten, post-ictal suppression/termination

Duration of therapeutic seizure will vary from individual to individual: usually 25-60seconds. If >2-3 mins seizure is aborted -> IV benzodiazepines

Question 5

Indications for ECT?

Answer 5

SEVERE depression

• urgent Tx response required
• if risky psychotropic therapy (I.e. Pregnancy, elderly)
• severe melancholic
• psychotic features
• treatment resistant

BIPOLAR
SCHIZOPHRENIA
NMS
CATATONIA
Underlying medical condition

Question 6

Contraindications?

Answer 6

• no absolute
• raised ICP (seizure -> increased blood flow -> increased ICP)
• recent stroke or MI (<6 weeks)
• AVM, aneurysm
• severe cardiopulmonary disease (anaesthetic risk)

Question 7

What are side effects of ECT?

Answer 7

Usually short lives/transient. No evidence of structural brain disease.

Cognitive - retrograde + anterograde amnesia, post-ictal confusion, mania, impaired judgement and problem solving skills

General

• CVS: tachy, Brady, ARRHYTHMIAS, HTN, ASYSTOLE
• somatic: headache, nausea, myalgia, arthralgia, fatigue
• anaesthetic: aspiration pneumonitis

Question 8

How does ECT affect drug interactions?

Answer 8

Increased seizure threshold for pts with :

• benzodiazepines
• anti-convulsants

Reduced seizure threshold
- clozapine, chlorpromazine

Transient ARRHYTHMIAS
- venlafaxine

Question 9

Medicolegal requirements?

Answer 9

Requirements for eligibility

• pt has a mental illness
• ECT authorised by psychiatrist who has examined the patient
• written consent to the treatment has been given (pt, on behalf of pt or GSB)

Question 10

When is consent not required?

Answer 10

If a psychiatrist considers pt has a mental illness of such a nature that administration of ECT urgently needed for pts well-being and it is not practical to gain consent

Question 11

Duration for consent of ECT?

Answer 11

Max course of 12 sessions

Max period of 3 months