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Postoperative delirium
In delirium, attention and awareness are disturbed, with an acute onset and a fluctuating course; it is common in older patients after surgery, is usually quiet and therefore missed, and is prevented mainly by non-drug measures — not by drugs.
Why it matters in the exam
The exam asks about the risk factors (age, dementia — the strongest, frailty, emergency surgery and hip fracture), the diagnostic tools (CAM, 4AT), the difference between hypoactive and hyperactive delirium, the drugs that worsen it (benzodiazepines, anticholinergics, pethidine), and treatment — finding the cause and non-drug measures, with an antipsychotic only when there is danger. It also asks whether regional anaesthesia prevents delirium more than general anaesthesia (not proven).
Diagnosis by CAM requires an acute onset and fluctuating course, plus inattention, plus one of two: disorganised thinking or an altered level of consciousness. Delirium is linked to higher mortality, longer stay, moving into care and long-term cognitive decline. The 2024 ESAIC guideline recommends screening before and after surgery, avoiding excessively deep anaesthesia (EEG monitoring), and limiting benzodiazepines; dexmedetomidine may reduce delirium in some patients.
In exam questions an older patient who looks "drowsy and quiet" on the day after surgery is often delirious rather than recovering well. The right step is a focused test of attention, not an added sedative. Family members are an important source: they recognise a change in behaviour quickly, and their presence helps orientation. On the ward daylight, a night-time sleep routine and the quick return of glasses and hearing aids are recommended.
Key points
- A disturbance of attention and awareness that starts acutely and fluctuates.
- The strongest risk factor: dementia; also age, frailty and emergency surgery.
- Diagnosis by CAM or 4AT; the hypoactive type is common and missed.
- Non-drug prevention; avoid benzodiazepines and anticholinergics.
- An antipsychotic only for distress or danger, at a low dose.
Summary table
| Issue | Details | Exam point |
|---|---|---|
| Types | Hypoactive (the most common), hyperactive, mixed | The hypoactive form is missed — it looks like a "calm patient" |
| Background factors | Age 65 or more, dementia, frailty, hearing or visual impairment, alcohol | Dementia — the strongest risk factor |
| Precipitating factors | Pain, infection, hypoxaemia, urinary retention, constipation, electrolyte disturbance, sleep loss | Look for and correct each one |
| Drugs that worsen it | Benzodiazepines, anticholinergics, antihistamines, pethidine | Review the drug list |
| Treatment | Non-drug measures; low-dose haloperidol only for distress or danger | Benzodiazepines only for alcohol or benzodiazepine withdrawal |
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Sources
- ESAIC evidence-based and consensus-based guideline on postoperative delirium in adults, 2024 update — Prevention and treatment
- American Geriatrics Society Clinical Practice Guideline for Postoperative Delirium in Older Adults, 2015 — Non-pharmacological and pharmacological measures
- Miller's Anesthesia, 9th edition (2020) — Geriatric Anesthesia; Postoperative Delirium and Cognitive Dysfunction
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.