AKT · Neurology/Seizures, delirium & paeds

Delirium

Acute, fluctuating disturbance of attention/cognition (organic)

Overview

An ACUTE, FLUCTUATING disturbance of attention and cognition with an altered level of consciousness, caused by an underlying organic insult (infection, drugs, metabolic, retention, pain). The exam point is distinguishing it from dementia (acute + fluctuating + inattention + clouded consciousness) and finding/treating the cause.

Recognise

Acute onset, FLUCTUATING course, INATTENTION, disorganised thinking, altered consciousness
Hyperactive (agitated, hallucinating) or HYPOACTIVE (drowsy, withdrawn — easily missed) or mixed
Precipitants (PINCH ME): Pain, Infection, Nutrition, Constipation, Hydration, Medication, Environment

Red flags

Hypoactive delirium is easily missed; a new acute confusion is delirium until proven otherwise — find the cause

Differentials & how to tell them apart

Dementiachronic, gradual, STABLE attention and consciousness — delirium is acute, fluctuating, inattentive (the two coexist: delirium superimposed on dementia)

Lewy body dementiaalso fluctuates + hallucinations — but chronic; exclude delirium first

Depression (pseudodementia)low mood, not clouded consciousness

Non-convulsive status epilepticusEEG; consider if unexplained fluctuating consciousness

Investigations

Identify the cause: bedside cognitive test (4AT), urinalysis/cultures, FBC/CRP, U&E, glucose, calcium, B12, TFTs, ABG, medication review, bladder scan (retention), consider imaging if focal signs/head injury.

Management

Identify and treat the cause + supportive non-drug measures; sedation only as a last resort

1Screen (4AT) and hunt the cause (PINCH ME); treat it. Non-pharmacological measures first: reorientation, hydration, sleep hygiene, mobilise, sensory aids, familiar faces.Gate: Use sedation (low-dose haloperidol) only for severe agitation/risk after non-drug measures fail — and AVOID antipsychotics in Parkinson disease/Lewy body dementia (use lorazepam instead)
2Treat the precipitant(s); review and stop deliriogenic drugs; prevent complications; follow up cognition (may unmask dementia).

Treat the cause; non-drug measures first — reorientation, hydration, sleep, mobilise, glasses/hearing aids

Short-term low-dose haloperidol — ONLY if severe agitation/risk and non-drug measures fail (NOT in Parkinson/Lewy body → use lorazepam)

Key points

Acute + fluctuating + inattention + clouded consciousness = delirium (vs the chronic, stable picture of dementia). Hypoactive delirium is missed. Antipsychotics are last-resort and dangerous in Lewy body/Parkinson.

Monitor & prognosis

Cognition/attention, cause resolution, function; reassess for underlying dementia.

Usually reversible once the cause is treated; associated with poor outcomes in the frail.

Source: NICE CG103 (delirium)