Delirium

Core concept. Delirium is acute brain failure: an acutely developing, fluctuating disturbance of attention and cognition secondary to a medical cause. Inattention is the core deficit — agitation is optional and often absent.

Recognise it. Ask three things at the bedside: has this changed acutely from baseline? Can the patient sustain attention (months of the year backwards)? Is there an identifiable medical trigger? A positive CAM or 4AT flags the case; DSM-5 confirms it.

Delirium versus dementia (must-write table). See below.

Find and fix the cause. Work through DELIRIUM IS VERY PAINFUL. In practice the highest-yield checks are: drug chart, infection screen, capillary glucose, sodium and calcium, hydration, bladder for retention, rectum for impaction, oxygenation, and uncontrolled pain.

Treat it. Correct the cause + multicomponent non-pharmacologic care (reorientation, spectacles and hearing aids, sleep protocol, early mobilisation, hydration, family at the bedside, no restraints) + T-A-DA for behaviour. Reserve low-dose haloperidol (0.25–0.5 mg) with ECG monitoring for danger to self or others; avoid benzodiazepines unless alcohol or benzodiazepine withdrawal. Explain to relatives that fluctuation and slow resolution are expected.

A 2025 systematic review and meta-analysis of 35 studies and 12,097 medically hospitalised older patients (Int J Nurs Stud) reported a pooled prevalence of 23.6% and a pooled incidence of 13.5%, and identified frailty, physical restraints, previous falls, illness severity, cognitive impairment and older age as the leading risk factors. The inclusion of physical restraints among the top risks is the practice-changing point — restraint is a cause of delirium, not a treatment for it.