Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
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Acute brain failure
New inattention, fluctuating arousal or behavioural change may be the first sign of hypoxia, sepsis, stroke, metabolic failure, drug toxicity, withdrawal or intracranial disease and can rapidly threaten airway, hydration, mobility and safety.
Action: Perform ABCDE, observations and capillary glucose, identify immediate neurological and medical threats, obtain collateral and 4AT, reconcile medicines, investigate several plausible causes in parallel and provide continuous supportive and harm-prevention care.
Synopsis
Recognise hyperactive, hypoactive and mixed delirium promptly, establish baseline cognition through collateral, identify interacting precipitants without diagnostic closure, and prevent avoidable delirium through a targeted multicomponent bundle.
Delirium is an acute and fluctuating disturbance of attention, awareness and cognition caused by an underlying physiological or substance-related insult.
First-line recognition uses observation for recent change plus the 4AT; a score of 4 or more suggests possible delirium but clinical concern overrides any score.
4AT assesses alertness, four orientation items, attention by months backwards and acute change or fluctuation; it does not require special training.
Key red flags
Reduced consciousness, airway compromise, hypoxia, shock, hypoglycaemia, seizure or focal neurology requires immediate resuscitation and cause-specific escalation.
Acute fluctuating inattention
Hours-to-days onset, distractibility and variable performance across a conversation or shift is the defining bedside pattern.
Investigation priorities
01
ABCDE and capillary glucoseFirst step
Identify immediate physiological threats. within a safe older-adult assessment.
Management branches
First-line recognitionStabilise, screen and establish acute change
New confusion, drowsiness, agitation, fall or functional decline occurs.
Perform ABCDE, glucose and urgent treatment and obtain last-known-well and baseline collateral.
Use 4AT and full examination, reconcile medicines and investigate several plausible causes in parallel.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.