Synopsis
Recognise acute disturbed attention as a medical syndrome, distinguish its course from primary psychosis and dementia, and manage uncertainty without delaying reversible-cause treatment.
- Delirium usually develops over hours or days and fluctuates; impaired attention and altered awareness are central clues.
- Dementia generally causes a longer progressive decline, while primary psychosis often preserves basic alertness and orientation.
- Hypoactive delirium can look like depression, fatigue or cooperation; reduced interaction does not mean the patient is well.
- Establish the patient's usual cognition and function through family, carers, records and staff who know them.
- Use the 4AT when delirium indicators are present; in critical care or recovery after surgery use CAM-ICU or ICDSC.
- If delirium and dementia cannot be distinguished, manage delirium first and reassess cognition after recovery.
- Treat causes, support sleep and orientation, optimise hearing and vision, and reserve antipsychotics for specific distress or risk after other measures fail.
Key red flags
A patient with established dementia who becomes newly drowsy, inattentive, agitated or less able to eat has possible delirium superimposed on dementia.
Focal neurological signs, meningism, seizure, head trauma, marked fever, severe headache or falling consciousness require urgent targeted medical escalation.
Investigation priorities
Identify immediately reversible threats and determine the urgency of medical intervention.
Management branches
Recent altered attention or awareness is reported or observed, with or without pre-existing cognitive impairment.
- Establish the change from baseline and assess immediate physiological threats, using the appropriate delirium instrument to support detection.
- Search actively for several simultaneous contributors and treat infection, pain, hypoxia, dehydration, retention or medication problems according to the findings.
- Provide repeated simple orientation, daylight cues, sleep protection, familiar support and hearing or visual aids, with mobilisation and nutrition as tolerated.
Key medicines
Haloperidol for distressing deliriumWhen haloperidol is appropriate, use it briefly, usually one week or less, starting at the lowest suitable dose. The cited oral-solution SmPC gives adults 1–10 mg orally per day in one to three doses, with increments no more often than every two to four hours if agitation persists. The corresponding older-patient initial dose is 0.5 mg orally; titrate cautiously, with a usual maximum 5 mg daily. Exceeding that requires prior higher-dose tolerance and individual benefit-risk reassessment.Avoid in Parkinson's disease or dementia with Lewy bodies and check QT-related contraindications. Obtain baseline ECG and correct electrolytes; monitor swallowing, extrapyramidal effects, orthostatic hypotension and cardiac symptoms. Individual frailty often warrants doses near the bottom of the range. Halve the initial dose in hepatic impairment; severe renal impairment may require smaller doses and slower adjustments.