Synopsis
Recognise delirium as an acute syndrome of impaired attention while actively identifying focal stroke, seizure, encephalitis and other neurological emergencies that can present through apparent confusion.
- Delirium is an acute, usually fluctuating disturbance of attention and awareness with additional cognitive change. Hyperactive, hypoactive and mixed forms occur; quiet withdrawal is commonly missed.
- Obtain baseline cognition, function and communication from someone who knows the patient, then establish hours-to-days onset, fluctuation and recent precipitant rather than accepting 'confused' as a diagnosis.
- Use the 4AT or the locally mandated validated tool when delirium is suspected, but treat it as a structured assessment rather than a laboratory test that replaces clinical judgement.
- Check glucose, oxygenation, ventilation, temperature, blood pressure, medication exposure, pain, urinary retention, constipation, hydration and withdrawal early because several triggers often coexist.
- Aphasia can look like confusion: test naming, repetition, comprehension and fluency. Neglect can look inattentive, visual-field loss can look disoriented and apraxia can look uncooperative.
- Sudden confusion with unilateral weakness, gaze deviation, visual loss, aphasia, neglect or severe imbalance should enter the stroke pathway even when a delirium trigger is also present.
- Non-convulsive seizure may cause fluctuating responsiveness, speech arrest, automatisms, eye deviation or unexplained failure to recover; urgent EEG advice is warranted when the clinical pattern fits.
- Fever, headache, personality change, focal deficit or seizure can signal encephalitis or meningitis. Empirical treatment must not wait for lumbar puncture when the procedure is delayed or unsafe.
- Medication reconciliation includes new prescriptions, dose changes, anticholinergic burden, opioids, benzodiazepines, corticosteroids, dopaminergic drugs, over-the-counter products, alcohol and illicit substances.
- Management begins with treating causes and providing orientation, hydration, sensory aids, sleep support, mobilisation and family involvement; restraint or sedation can worsen outcomes and needs exceptional justification.
- Document attention, arousal, focal examination, collateral baseline, capacity for the specific decision and the plan to reassess. Delirium does not equal permanent incapacity.
Key red flags
Reduced movement, slow responses, sleepiness, poor intake and withdrawal with impaired attention may be mistaken for depression, fatigue or 'pleasant confusion'. It carries substantial risk and requires the same cause search as agitation.
Agitation, fear, hallucinations, sleep reversal and attempts to leave occur with fluctuating attention and disorganised thought. Pain, hypoxia, retention, withdrawal and an unfamiliar environment can all amplify behaviour.
Receptive or global aphasia can present as nonsensical answers, inability to follow instructions and apparent confusion. Sudden onset, paraphasia, naming or repetition impairment and lateralising signs support urgent stroke assessment.
Neglect, visuospatial disorientation, extinction, dressing difficulty and poor insight can appear as global cognitive disturbance. A lateralised attention deficit with abrupt onset is a focal cerebral syndrome.
Subacute fever, headache, altered behaviour, memory disturbance, focal seizure or neurological deficit suggests brain inflammation. Normal initial imaging or absence of neck stiffness does not exclude encephalitis.
Persistent or fluctuating impaired awareness after a seizure, unexplained speech arrest, subtle twitching, automatisms or gaze deviation can reflect continuing electrical seizure despite no generalised convulsion.
Investigation priorities
Identify altered alertness, impaired attention, acute change and fluctuation in a structured way.
Management branches
Hours-to-days cognitive change, impaired attention or fluctuating alertness without an immediately dominant focal syndrome.
- Perform ABCDE and glucose, obtain collateral baseline, use 4AT or the local validated assessment, and examine for focal neurology, meningism, trauma, pain, retention, constipation and dehydration.
- Investigate and treat plausible precipitants, rationalise medicines and withdrawal risk, and implement orientation, sensory aids, hydration, nutrition, sleep, mobilisation and familiar support.
- Review attention and arousal serially, escalate failure to improve or new focal signs, and communicate the syndrome, capacity implications and safety plan at every transition.