Mnemonic

Delirium Versus Dementia

A memory aid for distinguishing delirium from dementia at the bedside.

Expansion

Onset, course, attention and consciousness separate them

Expansion

Feature Delirium Dementia
Onset Hours to days Months to years
Course Fluctuating, worse at night Slowly progressive
Consciousness Impaired Clear until late
Attention Markedly impaired Preserved until late
Hallucinations Common, often visual Less common early
Reversibility Usually reversible Usually not

Delirium may be hyperactive (agitated, the type that is recognised), hypoactive (withdrawn, drowsy, the commonest type and the most missed, with the worst prognosis), or mixed. Dementia is also the strongest risk factor for delirium, and the two coexist often.

Causes, using PINCH ME:

  • P - Pain
  • I - Infection
  • N - Nutrition, including thiamine
  • C - Constipation
  • H - Hydration and hypoxia
  • M - Medication, especially anticholinergics, opioids, benzodiazepines, and withdrawal
  • E - Environment and electrolytes

Assessment tools: the 4AT is quick and validated (alertness, AMT4, attention via months backwards, acute change or fluctuation). A score of 4 or more suggests delirium.

The management is to treat the cause, orientate, mobilise, restore sleep, remove catheters and lines, and involve family, with sedation reserved for genuine risk.