Acute confusion and delirium in adults
0Stop — call 999 and pre-alert — glucose and full observations at first contact, including home visits
- Reduced or deteriorating consciousness (cannot stay awake, GCS ≤13), ongoing or recurrent seizure, or critically ill → 999
- Suspected sepsis with any NICE high-risk criterion: new altered mental state, RR ≥25, HR >130, systolic BP ≤90, no urine for 18 h, mottled or ashen, cyanosis, non-blanching rash → 999
- Stroke (sudden confusion with a focal deficit), meningitis or encephalitis, opioid toxicity with respiratory depression, severe serotonin toxicity or NMS, severe hypoglycaemia not promptly corrected → 999
- While waiting: treat a low glucose now. Strongly suspected meningococcal disease → IM or IV ceftriaxone or benzylpenicillin as soon as possible, unless it delays transfer or there is a severe allergy. Do not delay transfer for cognitive testing or tests.
1Confirm — collateral history, then the 4AT
| 4AT | Meaning |
|---|---|
| ≥4 | Possible delirium → investigate and act. Too drowsy or agitated to test still scores ≥4. |
| 1–3 | Possible cognitive impairment |
| 0 | Unlikely; not excluded if the acute change is unknown |
Delirium: hours to days, fluctuates, poor attention. Dementia: months to years. New change on dementia → manage the delirium first.
2Screen — same-day hospital assessment if any
- No clear treatable cause after primary-care assessment → Same-day hospital
- Needs IV fluids, oxygen, IV antibiotics, monitoring or urgent metabolic correction → Same-day hospital
- Head injury on an anticoagulant or a non-aspirin antiplatelet → Same-day ED (NICE: consider CT within 8 h)
- Alcohol withdrawal → Same-day; suspected Wernicke's → Emergency transfer, parenteral thiamine first if available (oral not adequate)
- Severe agitation or risk of harm, no one to supervise, carer breakdown or unsafe home → Same-day
- Clinic BP ≥180/120 with new confusion → Same-day specialist
3Assess — head to toe, even if hard to assess
☐ Capillary glucose, RR, SpO₂, pulse, BP, temperature, AVPU/GCS, urine output ☐ Pupils, focal signs, neck stiffness, asterixis, clonus, rigidity ☐ Bladder (scan if available), faecal loading, skin, injury screen after a fall ☐ The actual medicine boxes, not only the repeat list
Same-day bloods if at home: FBC, U&E, CRP, LFTs, calcium, glucose, TFTs. Consider ECG, B12/folate, magnesium, drug levels.
Not: a dipstick alone to diagnose UTI; antibiotics for asymptomatic bacteriuria; CT head (a hospital test).
4Find the cause — PINCH ME; often more than one
- Infection — chest, skin, abdomen; UTI only with urinary or systemic features. Older adults may be afebrile.
- Medicines — opioids, anticholinergics, benzodiazepines, steroids, dopaminergics, digoxin, lithium; recent starts, stops, OTC. Do not stop benzodiazepines or antiepileptics abruptly without a plan.
- Metabolic, pain, retention, constipation — dehydration, AKI, hypoxia, sodium, calcium, glucose; occult fracture. Aged ≥60 with hypercalcaemia suggesting myeloma → Very urgent myeloma bloods (NG12).
- Neurological — subdural, stroke, non-convulsive seizure → 999 or same-day hospital.
- Uncertain — no clear treatable cause → same-day hospital. The first abnormal result may not be the whole answer.
5Treat today
- The cause: antimicrobials only for suspected or confirmed infection; oral fluids; relieve retention or constipation; reduce culprit medicines.
- Non-drug care, everyone: familiar person, reorientation, glasses, hearing aids, light by day, dark nights, food, drink, mobilise.
- Distress or risk, de-escalation failed: consider short-term haloperidol (usually ≤1 week), lowest dose, after ECG and electrolytes, with a stop date. Not in Parkinson's or Lewy body dementia → specialist advice. No routine benzodiazepines. Doses: NICE/SPC, BNF, local formulary.
6Where to manage and refer
- Home only if all: clear treatable cause, stable, drinking, someone supervising, safe home, same-day results reviewed, daily review. Consider a virtual ward.
- Old-age psychiatry or geriatrics: persistent delirium, severe distress or psychosis, diagnostic doubt, haloperidol contraindicated.
- Memory service only once delirium has resolved and cognition is not back to baseline.
- Capacity is decision-specific (MCA 2005). Raise safeguarding for neglect, abuse or an unsafe home.
7Never reassure by
- A normal cognitive score without a collateral history.
- A positive urine dipstick as "the cause".
- A quiet, sleepy patient: hypoactive delirium is easily missed.
- No fever in an older person.
- "It's just the dementia getting worse."
- No fall witnessed: a subdural can follow a fall days ago.
8Safety-net — say it to the carer, then document it
999 “Call 999 if they become harder to wake, develop new weakness or speech difficulty, have a fit, develop a non-blanching rash or breathing difficulty, or fall and hit their head while taking a blood thinner.” Same day “Contact the surgery the same day if they are worsening, stop eating or drinking, develop a fever, become very agitated, or are not beginning to improve within two or three days.”
Follow-up: review ideally daily in the acute phase (observations, 4AT, intake, results, carer coping). Not improving in 48–72 h → reassess, look for a second cause, consider admission. Antipsychotic: review within days, stop usually within 1 week.