🩺 General MedicineNeurology / GeriatricsStudentInternResident

Delirium (Acute Confusional State)

Also known as: acute confusional state · acute brain failure

An acute, fluctuating disturbance of attention and awareness with disorganised thinking, caused by an underlying medical problem — very common in hospital, often missed, and linked to poor outcomes. It may be hyperactive, hypoactive (easily missed) or mixed.

Source · Reviewed 2026-08-15 · v1.0— AI-assisted draft — verify against the cited guideline before clinical use.

⚕️ Education only — not medical advice. Verify against the latest official guideline and your local protocol; confirm every drug dose against the cited source before clinical use.

Who gets it

Older, frail or cognitively-impaired (dementia) and very ill patients; precipitated by infection, drugs, pain, dehydration/electrolytes, hypoxia, urinary retention/constipation and an unfamiliar environment.

Red flags — escalate / refer

New confusion in an unwell patient → find and treat the cause; a sudden change with focal signs → exclude stroke or another serious cause.

Work-up / diagnosis

1Recognise it (a tool such as 4AT/CAM) — a clinical diagnosis — then find the cause with a targeted screen (infection, glucose/electrolytes/calcium, drug review, hypoxia, retention, constipation, pain).
2Review the medication list and compare with the baseline cognition (collateral history).

Management — overview

Treat the underlying cause(s).
Non-drug measures first — reorientation, familiar faces, sleep and lighting, hydration/nutrition, early mobilisation, glasses/hearing aids; avoid catheters and restraints.
Reserve a short-term, low-dose antipsychotic only for severe distress or risk (use with great caution/avoid in Parkinson's/Lewy body dementia).
Actively prevent it in at-risk inpatients.

In-depthFull dosing & advanced protocol

Drug dosing

Treat the cause (no drug treats delirium itself)

Reverse precipitants

Adult dose: Per the specific cause
Route: Per cause

ICMRStandard Treatment Workflows (STWs), India — Dept. of Health Research & ICMR (2022+) ↗

Short-term low-dose antipsychotic (selected)

Severe agitation/risk only

Adult dose: Lowest dose, shortest time — per protocol
Route: Oral / IM

Caution: Avoid/great caution in Parkinson's/Lewy body; sedatives often worsen delirium.

WHOWHO mhGAP Intervention Guide (mental health in non-specialist settings) ↗

Delirium is not dementia (but they coexist)

Delirium is acute, fluctuating and marked by inattention; dementia is chronic and progressive.
Hypoactive delirium is quiet and commonly missed — screen actively.
New confusion or a fall in an older person is delirium until proven otherwise.

ICMRStandard Treatment Workflows (STWs), India — Dept. of Health Research & ICMR (2022+) ↗

References

Guidelines change. If something here is out of date, tell us — we keep these current.

🚩 Report outdated / suggest update

More protocols

HypertensionPersistently raised arterial pressure (≥140/90 mmHg) — a leading, modifiable cause of stroke, heart attack, heart failure and kidney disease.DengueAn Aedes-borne viral febrile illness. Most cases self-limit, but plasma leakage can cause severe dengue — early recognition of warning signs and careful fluid therapy save lives.MalariaA mosquito-borne protozoal (Plasmodium) febrile illness. In India P. vivax and P. falciparum predominate; prompt diagnosis and species-specific treatment prevent severe disease.

Loading…

👤 Who gets it

🚩 Red flags — escalate / refer

🔎 Work-up / diagnosis

🧭 Management — overview

💊 Drug dosing

Treat the cause (no drug treats delirium itself)

Short-term low-dose antipsychotic (selected)

📈 Delirium is not dementia (but they coexist)

📚 References

More protocols

👤 Who gets it

🚩 Red flags — escalate / refer

🔎 Work-up / diagnosis

🧭 Management — overview

💊 Drug dosing

Treat the cause (no drug treats delirium itself)

Short-term low-dose antipsychotic (selected)

📈 Delirium is not dementia (but they coexist)

📚 References

More protocols

Who gets it

Red flags — escalate / refer

Work-up / diagnosis

Management — overview

Drug dosing

Delirium is not dementia (but they coexist)

References

Who gets it

Red flags — escalate / refer

Work-up / diagnosis

Management — overview

Drug dosing

Delirium is not dementia (but they coexist)

References