Confusion / Delirium

First actions / assessment

• Assess ABCDE first and check reversible life-threatening causes immediately: capillary glucose, oxygenation, perfusion, temperature, pain, and drug/alcohol history. Clarify whether this is an acute change over hours to days and whether symptoms fluctuate
• get collateral history from relatives/carers because delirium is a clinical diagnosis and history is crucial. Ask about baseline cognition, dementia, previous delirium, onset, course, hallucinations, inattention, sleep-wake reversal, agitation vs hypoactivity, falls, infection symptoms, urinary retention, constipation, pain, poor intake, dehydration, recent surgery, trauma, new medicines, missed medicines, intoxication, withdrawal, and substance use. Examine vitals, hydration, neurological status, pupils, meningism where relevant, focal deficits, signs of head injury, chest, abdomen, bladder retention, stool loading, and sources of infection. Use 4AT for probable delirium in most acute settings
• in ICU/recovery use CAM-ICU or ICDSC. Investigations guided by presentation commonly include bedside glucose, ECG, CBC, U&E/creatinine, LFTs, CRP, calcium, venous/arterial blood gas if indicated, urinalysis, CXR when appropriate, cultures if sepsis suspected, toxicology when relevant, CT brain for head injury/focal deficits/anticoagulation/reduced GCS/persistent unexplained delirium, and LP only when CNS infection/inflammation is suspected after assessing contraindications.