Delirium accounts for approximately 10 per cent of the SCE Geriatric Medicine exam and is one of the most frequently tested topics across multiple exam sittings. It is also a topic where candidates lose marks by defaulting to pharmacological management when the evidence base — and the correct exam answer — prioritises non-pharmacological approaches.
The 4AT screening tool
The 4AT is the recommended bedside screening tool for delirium in the UK. It takes less than two minutes to administer and does not require specific training. The four components are alertness (normal = 0, abnormal = 4), AMT-4 (age, date of birth, current location, current year — all correct = 0, one or more errors = 1, untestable = 2), attention (months of the year backwards — achieves 7 or more = 0, fewer than 7 = 1, untestable = 2), and acute change or fluctuating course (evidence of significant change or fluctuation = 4, no = 0).
A total score of 4 or above suggests delirium is likely. A score of 1 to 3 suggests possible cognitive impairment and requires further assessment. A score of 0 makes delirium unlikely but does not exclude it.
The exam tests your knowledge of the 4AT specifically — not the CAM (Confusion Assessment Method), which is the dominant tool in North American practice but is less commonly used in UK clinical settings. Know the four components and the scoring thresholds.
Diagnosis — delirium vs dementia vs depression
The SCE frequently presents a clinical scenario and asks you to distinguish between delirium, dementia, and depression. The key distinguishing features are as follows.
Delirium has an acute onset (hours to days), a fluctuating course, impaired attention as the cardinal feature, often a reversible precipitant (infection, medication, metabolic disturbance), and the patient is typically acutely unwell. Dementia has an insidious onset (months to years), a progressive course, memory impairment as the early feature with attention relatively preserved in early stages, and the patient is typically medically stable. Depression can present with apparent cognitive impairment (pseudodementia) but has a subacute onset, pervasive low mood, and the patient often gives "don't know" answers rather than confabulating.
Delirium can be superimposed on dementia — this is a common and frequently tested scenario. A patient with known dementia who presents with acute deterioration in cognition, new inattention, or altered consciousness should be assessed for delirium as the primary diagnosis, with the underlying dementia as a predisposing factor.
Identifying the precipitant
Once delirium is diagnosed, the management priority is identifying and treating the underlying cause. The common precipitants tested in the exam are infection (most commonly UTI and pneumonia — though note that a positive urine culture in an elderly patient does not automatically mean UTI is the cause of delirium, given the high prevalence of asymptomatic bacteriuria in older adults), medications (opioids, benzodiazepines, anticholinergics, corticosteroids, and new or recently changed drugs), metabolic disturbance (AKI, electrolyte abnormalities, hypoglycaemia, hypercalcaemia), constipation and urinary retention, pain, and environmental factors (recent hospital admission, ward transfer, sleep deprivation).
The exam tests your ability to identify the most likely precipitant from the clinical information provided. A common trap is assuming UTI in every delirious older patient when the urinalysis is positive — you must evaluate whether the urinary findings are likely to be the cause or incidental.
Non-pharmacological management — the correct first-line
NICE CG103 (Delirium: prevention, diagnosis and management) is unequivocal: non-pharmacological management is first-line. This includes reorientation (clocks, calendars, familiar objects, consistent staff), ensuring adequate hydration and nutrition, promoting sleep hygiene (reducing noise and light at night, avoiding unnecessary observations), early mobilisation, correcting sensory impairment (ensuring hearing aids and glasses are available and used), avoiding unnecessary catheterisation and physical restraints, and involving family members in care.
The exam frequently presents a delirious patient and asks for the most appropriate management. If the options include both a non-pharmacological intervention and a pharmacological one, the non-pharmacological option is almost always the correct answer for the initial management step. Candidates who default to haloperidol lose marks.
Pharmacological management — when and what
Pharmacological management of delirium is reserved for patients who are at risk of harming themselves or others, or where the severity of agitation or distress prevents investigation and treatment of the underlying cause. It is not routine.
When pharmacological management is required, NICE recommends starting with the lowest effective dose of haloperidol (typical dose 0.5 mg orally or IM, maximum 2 mg in 24 hours for older adults). Haloperidol is contraindicated in Parkinson's disease and Lewy body dementia — in these patients, low-dose lorazepam (0.5 mg) is an alternative, though benzodiazepines can worsen delirium and should be used with extreme caution.
The exam tests the haloperidol contraindication in Parkinson's disease and Lewy body dementia specifically. This is a high-yield fact — if the vignette mentions either condition, haloperidol is wrong regardless of how agitated the patient is.
Prevention
Delirium prevention is also tested, particularly in the perioperative context. NICE recommends a multicomponent intervention for at-risk patients (those aged over 65, those with known cognitive impairment, those with hip fracture, and those with severe illness). The preventive interventions mirror the non-pharmacological management strategies — reorientation, hydration, sleep hygiene, mobilisation, sensory correction, and medication review.
There is no evidence for pharmacological prophylaxis of delirium. Neither haloperidol nor melatonin is recommended for prevention.
Common exam pitfalls
Prescribing haloperidol as first-line without attempting non-pharmacological management. Diagnosing UTI as the cause of delirium based solely on a positive urine culture in an older patient. Failing to identify delirium superimposed on dementia. Assuming all delirious patients need sedation. Using benzodiazepines as first-line (except in alcohol withdrawal delirium or Parkinson's/Lewy body disease). Omitting the 4AT or using the wrong screening tool.
iatroX's SCE Geriatric Medicine bank includes extensive delirium content covering the 4AT, differential diagnosis, precipitant identification, non-pharmacological management, and the haloperidol contraindications. The adaptive algorithm ensures delirium questions are weighted proportionally to the exam. All included at £29 per month or £99 per year.