Medical screening and acute behavioural disturbance

Safety: Calm environment, exits clear, remove weapons, adequate staff, de-escalation first, personal safety.

Medical screening (not a rubber stamp): History + collateral; full vitals including temperature; bedside glucose always; focused exam for focal neuro, meningism, toxidrome; investigations guided by findings (ECG if QT/TCA risk, gas, U&E, CT if red flags).^[1] Four gates: normal vitals? normal glucose? time course fits known psychiatric illness? any focal neuro/cognitive deficit?

Delirium vs primary psychosis: Delirium — acute, fluctuating, inattention, often visual hallucinations, abnormal vitals/medical cause. Primary psychosis — clearer sensorium, auditory hallucinations, systematised delusions, often normal vitals.^[1]

Agitation ladder:

1. De-escalation / offer oral medication.
2. IM droperidol 5–10 mg (first-line many Australasian EDs for undifferentiated severe agitation) or IM olanzapine / haloperidol with monitoring.
3. Benzodiazepine e.g. lorazepam 1–2 mg IV/IM/PO or midazolam with airway monitoring.
4. Avoid IM olanzapine + IM benzo combination.
5. Post-sedation: SpO2, RR, BP, conscious level, ECG for QT (droperidol/haloperidol).^[2]

Capacity / MHA: Assess understand–retain–weigh–communicate. If risk of serious harm and criteria met under local Mental Health Act and patient refuses necessary care, document and complete involuntary detention paperwork; treat medical emergencies under necessity/common law as required.^[3]