Neurology >
Delirium
“Acute or subacute brain failure in which impairment of attention is accompanied by abnormalities of perception and mood”
Risk Factors
- Disease – Dementia, constipation, pneumonia, UTI
- Post-surgical complications – medication e.g. benzodiazepines
- Altered metabolic homeostasis
Extremes of age - Injured brain – previous head injury, alcohol brain damage, previous stroke
- Dislocation to an unfamiliar environment e.g. hospital admission
- Sleep deprivation
- Sensory extremes
- Immobilization
Aetiology
- Systemic infection – particularly with high fever
- Metabolic disturbance – hepatic failure, CKD, dehydration, hypoxia
- Vitamin deficiency – thiamine, nicotinic acid, B12
- Endocrine disease – hypothyroidism, Cushing syndrome
- Intracranial causes – trauma, tumours, abscess, subarachnoid haemorrhage, epilepsy
- Drug intoxication – anticonvulsants, antimuscarinics, anxiolytics, TCAs, dopamine agonists, digoxin
- Drug/alcohol withdrawal
Pathophysiology
- Poorly understood
Clinical Presentation
- Difficulties with attention span, concentration, remaining conscious
- The patient usually has a reversed sleep cycle i.e. awake in the night, sleeps in the day
- Disorganised or delayed thinking
- Can present as hypoactive or hyperactive symptoms
- HYPERactive: agitated, aggressive, delusions/hallucinations (tactile/visual)
- HYPOactive: drowsy, less reactive, withdrawn
- “DELIRIUM”
- Disordered thinking
- Euphoric/fearful/depressed/angry
- Language impaired
- Illusions/delusions/hallucinations
- Reversal of sleep/wake cycle
- Inattention
- Unaware/disoriented
- Memory deficits
Investigations
- Find the cause!
- Bloods:
- FBC
- U + Es
- LFTs
- Blood glucose
- ABG
- Septic screen
- Malaria films
- Imaging:
- ECG
- CT/MRI
- Special:
- LP
- EEG
- Diagnostic criteria
- Disturbance of consciousness
- Change in cognition
- Develops in hours to days
- Fluctuation over the course of the day
Management
- Treat underlying cause.
- General management:
- Nurse in moderately lit, quiet room and aim to reduce confusion as much as possible (e.g. same staff, ensure the patient has hearing/visual aids if necessary, place clock in the room to ensure they are oriented with time)
- Try to get patient to care for themselves
- Minimize sedatives
Complications
- Brain recovery usually lags behind recovery from the physical illness
Differentials
- Anxiety
- Primary mental illness (e.g. schizophrenia)
- Dementia