Delirium in the elderly
Delirium is an acute neuropsychiatric syndrome common in older people presenting to the emergency department (ED). It is a medical emergency: prompt recognition, identification and treatment of reversible causes, and delivery of multicomponent non‑pharmacological care reduce morbidity, length of stay and mortality.
The ED role is to screen early, stabilise, search for precipitants, minimise iatrogenic harms, and communicate the diagnosis and plan to inpatient teams, primary care and carers (NICE CG103; RCEM).
Diagnosis and screening
Delirium is a clinical diagnosis. Screen all older patients and anyone with acute cognitive or behavioural change using a brief validated tool (for example, 4AT) and document the result (RCEM recommendation). Confirm clinically using DSM‑5 features:
- Acute onset with a fluctuating course (hours-days).
- Disturbance of attention and awareness (inattention is central).
- Additional cognitive disturbance (memory, orientation, language, perception).
- Evidence the disturbance is due to a medical condition, substance or toxin.
Clinical subtypes
- Hyperactive: agitated, restless, often obvious.
- Hypoactive: quiet, drowsy, withdrawn - commonly missed and associated with worse outcomes.
- Mixed: fluctuates between hyperactivity and hypoactivity.
Why delirium occurs
Delirium arises from an interaction of predisposing vulnerability and precipitating insults.