Delirium is a sudden change in attention, awareness and thinking caused by an underlying medical problem. It is very common in older people in hospital, particularly after surgery and in intensive care, and is linked to longer stays, falls, loss of independence, new dementia and death. Yet it is often missed, especially the quiet “hypoactive” type. Nurses, who see patients around the clock, are best placed to spot it.
Delirium vs dementia
| Delirium | Dementia | |
|---|---|---|
| Onset | Sudden (hours to days) | Gradual (months to years) |
| Course | Fluctuates, often worse at night | Slowly progressive |
| Attention | Markedly impaired | Usually normal in early stages |
| Consciousness | Altered (drowsy or hyperalert) | Usually normal |
| Reversible? | Often, if the cause is treated | No |
People with dementia are at much higher risk of delirium, and the two often occur together. Ask family: “Is this how they normally are?”
Three types
- Hyperactive: agitated, restless, pulling at lines, hallucinating. Easy to notice.
- Hypoactive: withdrawn, sleepy, slow, quiet. Often missed or mistaken for depression or tiredness.
- Mixed: switches between the two.
Screening: the 4AT
The 4AT is a quick (under 2 minutes) screening tool widely used in the UK and internationally. It needs no special training:
- Alertness: normal, or clearly abnormal (drowsy or agitated).
- AMT4: age, date of birth, place, current year.
- Attention: months of the year backwards.
- Acute change or fluctuating course.
A score of 4 or more suggests possible delirium; 1–3 suggests possible cognitive impairment. Use the official form and scoring. In ICU, the CAM-ICU is common.
Find the cause: PINCH ME
- Pain.
- Infection (urine, chest, wounds, sepsis; malaria in endemic areas).
- Nutrition and hydration: dehydration, low blood glucose.
- Constipation (and urinary retention).
- Hydration and electrolytes (sodium, calcium).
- Medication: opioids, sedatives, anticholinergics, steroids, new drugs, and alcohol or drug withdrawal.
- Environment: unfamiliar surroundings, noise, lack of sleep, sensory impairment.
Often there are several causes. Also consider hypoxia, stroke, heart attack, and head injury after a fall.
Prevention that works
NICE estimates that multicomponent interventions can prevent around a third of delirium cases. Key measures:
- Orientation: clocks, calendars, explaining where they are and who you are.
- Glasses and hearing aids in and working.
- Hydration and nutrition: help with eating and drinking.
- Sleep: reduce noise and light at night; avoid unnecessary night-time observations and procedures.
- Early mobilisation.
- Pain assessment and treatment.
- Avoid unnecessary catheters and moving patients between wards.
- Medication review.
- Family involvement: familiar faces and objects.
Caring for a patient with delirium
- Treat the cause, escalating promptly.
- De-escalate agitation: calm voice, short sentences, don’t argue, reduce stimulation.
- Keep them safe: falls prevention, closer observation, low bed.
- Avoid physical restraint; use antipsychotics or sedatives only as a last resort, short-term, as prescribed, when the patient is distressed or at risk.
- Explain to families that delirium is common, usually temporary, and caused by illness, not “madness”.
- Document and hand over the diagnosis so it is not lost.
Recovery can take days to weeks, and some people never fully return to their previous level. Follow-up after discharge is important.
Related: Falls prevention · Post-operative care · Hypoglycaemia
Based on NICE CG103 (Delirium: prevention, diagnosis and management), the 4AT (www.the4at.com) and SIGN 157. Educational content: follow your local delirium pathway.