Synopsis
Recognise hyperactive, hypoactive and mixed delirium promptly, establish baseline cognition through collateral, identify interacting precipitants without diagnostic closure, and prevent avoidable delirium through a targeted multicomponent bundle.
- Delirium is an acute and fluctuating disturbance of attention, awareness and cognition caused by an underlying physiological or substance-related insult.
- First-line recognition uses observation for recent change plus the 4AT; a score of 4 or more suggests possible delirium but clinical concern overrides any score.
- 4AT assesses alertness, four orientation items, attention by months backwards and acute change or fluctuation; it does not require special training.
- Always obtain collateral for baseline cognition, function and exact onset and document whether delirium is hyperactive, hypoactive or mixed.
- Use ABCDE and glucose before a lengthy cause list. Serious illness may present through delirium without fever, pain or marked laboratory inflammation.
- Search multiple causes using history, full examination, medicines, pain, bowel and bladder, hydration, oxygenation, infection and targeted tests.
- A CT head is not routine for every delirium; use it for trauma, focal neurology, seizure, anticoagulation with concern or unexplained persistent reduction.
- Prevention is multicomponent: orientation, familiar contact, hydration, nutrition, pain control, mobility, sleep, oxygen, medication review and sensory aids.
- Avoid unnecessary catheters, bed moves, restraints and night disturbance; identify a consistent team member and communicate baseline and preferences.
- Document the syndrome and probable contributors explicitly so later teams do not misread delirium as new dementia or behavioural choice.
Key red flags
Reduced consciousness, airway compromise, hypoxia, shock, hypoglycaemia, seizure or focal neurology requires immediate resuscitation and cause-specific escalation.
Sudden headache, head injury, anticoagulation, focal deficit or persistent unexplained reduced arousal lowers the threshold for urgent brain imaging.
Rigidity, fever, autonomic instability or clonus after medicine change raises neuroleptic malignant syndrome, serotonin toxicity or severe withdrawal.
Hypoactive delirium presents as quiet withdrawal, slow response or reduced intake and is easily mistaken for sleep, depression or advanced dementia.
Known dementia does not explain an abrupt fluctuation; delirium and dementia commonly coexist and both baseline and acute change must be documented.
A positive urine dipstick or bacteriuria without compatible symptoms or systemic evidence must not end the search for another cause.
Hours-to-days onset, distractibility and variable performance across a conversation or shift is the defining bedside pattern.
Drowsiness, reduced movement, sparse speech and poor intake can look cooperative or depressed and requires active screening.
Investigation priorities
Identify immediate physiological threats. within a safe older-adult assessment.
Management branches
New confusion, drowsiness, agitation, fall or functional decline occurs.
- Perform ABCDE, glucose and urgent treatment and obtain last-known-well and baseline collateral.
- Use 4AT and full examination, reconcile medicines and investigate several plausible causes in parallel.
- Record delirium type, contributors, capacity and prevention plan and repeat assessment with fluctuation.