Delirium

Question 1

Delirium is an organic brain disorder.

Organic brain disorders result from structural pathology i.e. dementia

OR

Organic brain disorders can result from disturbed central nervous system function i.e. fever induced delirium

Answer 1

INFO CARD

Question 2

What is delirium?

Delirium is also known as:

=> toxic confusional state

=> acute organic psychosis.

Answer 2

Delirium is an acute or subacute brain failure resulting in:

=> impairment of attention
=> abnormalities of perception and mood
=> acute and fluctuating confusion

Question 3

How common is delirium?

Answer 3

Delirium is the most common type of psychosis seen in hospital setting.

Question 4

What are the clinical features of delirium?

Answer 4

=> Agitation worse at night

=> Sleep reversal i.e. awake during night, asleep during day - consequence of night agitation

=> acute onset, fluctuating course

=> poor attention

=> disordered thinking

=> altered level of consciousness

=> disorientation

=> memory impairment

=> psychomotor agitation / retardation

=> hallucinations / misperception

2 forms of delirium:

=> Agitated, hyperactive form

=> Hypoactive form in the elderly (worse prognosis)

=> Patients fluctuate between these two forms

Question 5

What are the clinical signs in the acute phase of delirium?

Answer 5

Acute phase:

=> thought and speech incoherent

=> memory impaired

=> misperceptions occur

=> episodic visual hallucinations

=> persecutory delusions

As a consequence the patient might be frightened, suspicious, restless and uncooperative.

Question 6

Which factors predispose you to delirium?

Answer 6

Extremes of age
=> developing or deteriorating brain

Damaged brain 
=> dementia, 
=> previous head injury, 
=> alcohol brain damage, 
=> previous stroke

Dislocation to an unfamiliar environment i.e. hospital admission

Sleep deprivation

Sensory extremes (overload or deprivation)

Immobilisation

Visual or hearing impairment

Question 7

Causes of delirium:

1. Metabolic disturbances 
=> Hepatic failure
=> Chronic kidney disease
=> Disorders of electrolyte balance, dehydration
=> Hypoxia

2. Endocrine disease:
   => Hypothyroidism
   => Cushing’s syndrome
3. Vitamin deficiency:
   => Thiamine (Wernicke-Korsakoff’s syndrome, beriberi)
   => Nicotinic acid (pellagra)
   => Vitamin B12

Answer 7

Causes of delirium:

4. Systemic infections
   => any infection esp. with high fever e.g. malaria or septicaemia

5. Drug intoxication: 
=> Anticonvulsants 
=> Antimuscarinics 
=> Anxiolytics / hypnotics 
=> Tricyclic anti-depressants 
=> Dopamine agonists 
=> Digoxin

• drug interactions or missed medications
  6. Drug/alcohol withdrawal

7. Intracranial causes:
=> Trauma
=> Tumour 
=> Abscess
=> Subarachnoid haemorrhage 
=> Epilepsy

8. Pain
9. Constipation / urinary retention

Question 8

What is the diagnostic criteria for delirium?

Answer 8

Disturbance of consciousness:
=> reduced awareness of environment
=> reduced ability to focus, sustain or shift attention

Change in cognition:
=> Memory deficit, disorientation, language disturbance, perceptual disturbance

Disturbance develops over a short period (hours to days)

Fluctuation over the coarse of a day

4AT bedside scale

• Alertness
• AMT4 (age, date of birth, place, date)
• Attention
• Acute change / fluctuating course

CAM (confusion assessment method)

1. Hx if acute onset of change in patients normal mental status and fluctuating course

AND

2. Lack of attention (assessed by asking months in reverse)

AND EITHER

3. Disordered thinking
4. Altered level of consciousness

Question 9

How do you manage delirium?

Answer 9

Take a history from a witness

Examination may reveal cause

Hydrate and nurse patient in a quiet single room

Reduce temperature in fevers

All current drug therapy should be reviewed and stopped if possible

Stop psychoactive drugs

Question 10

What are the differential diagnosis for delirium?

Answer 10

Delirium tremens

Lewy body dementia

Question 11

What is the prognosis for delirium?

Answer 11

Delirium clears within a week or two but brain recovery lags behind

Prognosis depends on successful treatment of causative disease and also on the underlying state of the brain.

=> 25% of patients with delirium have underlying dementia

=> 15% don’t survive their underlying illness

=> mortality rates increased in patients with delirium

Question 12

What is delirium tremens?

Answer 12

Delirium tremens = the most serious withdrawal state and occurs 1-3 days after alcohol cessation.

=> Disorientated, agitated, marked tremor, visual hallucinations i.e. insects or small animal

=> Signs: sweating, tachycardia, tachypnoea and pyrexia

=> Complications: dehydration, infection, hepatic disease, Wernicke-Korsakoff’s syndrome

Question 13

What is carphology?

Answer 13

The motion of delirious or senile patients especially motions of searching for and grasping at imaginary objects, plucking at bedclothes.

Uncommon but highly suggestive of delirium Esp in hypoactive delirium

Also known as floccination

Question 14

What are the 3 types of delirium?

Answer 14

Hypoactive delirium (50%) ie pleasantly confused

Hyperactive delirium (25%) ie wild man

Mixed picture delirium (25%) with sleep cycle reversal

*hypoactive delirium most worrying because delay in recognising and misdiagnosing hypoactive delirium, therefore high risk of deterioration.