Level 1 of 6Core
The agitated patient: acute agitation and psychosis
The core to-do list — diagnose and manage, at a glance
Diagnose— recognise it
- Treat agitation as an organic emergency until an organic cause has been excluded — it is a syndrome of arousal, not a diagnosis. Capillary glucose is the first test in every agitated patient without exception: below 4 mmol/L requires immediate treatment (below 3 mmol/L in a child, below 2.6 mmol/L in a neonate).
- Physiology before psychiatry: SpO2 below 94% or any respiratory distress — hypoxaemia and hypercapnia both produce a restless combative patient; hypotension, tachycardia or cold peripheries — agitation is a classical early sign of shock, and the restless injured patient is bleeding until proved otherwise; temperature above 39°C with rigidity (NMS), clonus (serotonin syndrome) or a stimulant history is a hyperthermic emergency, not a behavioural one.
- Red flags: focal signs, unequal pupils, new seizure, neck stiffness, fluctuating conscious level, head injury, anticoagulation or a fall; age over 65 with new confusion; an infant under 3 months — never behavioural: it is sepsis, hypoglycaemia or raised intracranial pressure. Onset over hours in a person previously well is organic; watch the quiet, guarded, paranoid patient — calm concealment is more dangerous than noise.
- Separate delirium from psychosis: delirium — onset over hours to days, fluctuating and worse at dusk, clouded consciousness, grossly impaired attention (cannot sustain the months backwards), fleeting visual hallucinations. Primary psychosis — clear sensorium, consistent second- or third-person auditory hallucinations, systematised persecutory delusions, previous episodes, often recent cessation of medication; mania adds pressured speech, grandiosity and reduced need for sleep.
- Timing discriminates withdrawal, pupils and skin discriminate toxicity: alcohol withdrawal begins 6–24 hours after the last drink; seizures cluster at 12–48 hours; delirium tremens at 48–96 hours with hallucinations classically of insects or threads. Stimulants: dilated pupils, tachycardia, hypertension, sweating. Anticholinergic: dry, flushed, hyperthermic, mydriatic, absent bowel sounds. Serotonin syndrome: diaphoresis, hyperreflexia, clonus greatest in the legs. NMS: lead-pipe rigidity, autonomic instability, raised creatine kinase, onset over days.
- In older people agitation is nearly always delirium saying something specific — pain, urinary retention, faecal impaction, infection, a new drug, dehydration or a blocked catheter; an agitated older patient who is anticoagulated, or whose conscious level fluctuates, has a subdural haematoma until imaging says otherwise. Read the prodrome of violence: pacing, rising volume, refusal to sit, intrusion into personal space, clenched fists, prolonged staring — then assault.
Manage now— do this, in order
- Exclude reversible physiology before sedating — a drug given before a glucose measurement is a drug given blind. Hypoglycaemia: 50 mL of 25% glucose IV in an adult (children 2 mL/kg of 10% glucose IV), recheck at 10 minutes; thiamine 100 mg IV or IM before or with the glucose in anyone malnourished or alcohol-dependent.Doctor / Nurse
- Hypoxaemia: oxygen titrated to target and a blood gas — never sedate a hypercapnic patient without ventilatory support. Hypoperfusion is resuscitated as shock with a search for the bleeding source. Temperature above 39°C: strip, cool actively and externally, cooled IV fluids and a benzodiazepine to abolish muscular hyperactivity — antipyretics are ineffective in toxic and exertional hyperthermia.Doctor / NurseNot available at your setup — Arterial blood gas.
- The drug is the last rung of a ladder: environment, then verbal de-escalation, then oral medication offered as a choice, then IM medication. De-escalation costs 90 seconds and works more often than expected: reduce stimulation, remove the audience, keep two arms' lengths, stand at an angle with hands visible, one voice only; address the emotion, neither argue with nor endorse a delusion; offer a chair, water, the toilet, analgesia — unmet basic needs cause a large share of agitation and none of them respond to haloperidol.
- Match the drug class to the cause — the single most consequential prescribing decision: benzodiazepine for alcohol or sedative withdrawal and stimulant toxicity (never an antipsychotic first in withdrawal — it lowers the seizure threshold); antipsychotic for primary psychosis, mania and established psychotic aggressive states; benzodiazepine plus withdrawal of the offending agent for serotonin syndrome, NMS and anticholinergic delirium; for delirium in the older person, find and fix the cause — drugs last, lowest and singly. Cause unknown, no head injury or respiratory compromise → start with a benzodiazepine.Doctor / Nurse
- Give medications sequentially, 30 minutes to 1 hour apart — stacking agents within minutes is the mechanism of iatrogenic respiratory arrest. Adult doses: lorazepam 0.5–1 mg oral/IM, repeat after 30–60 minutes, up to 1–2 mg every 2 hours; diazepam 5 mg, or 10 mg IV then 5–10 mg IV every 3–5 hours, or 10–20 mg IV repeated in stimulant toxicity; midazolam 5–10 mg IM (lower in the frail — the most respiratory-depressant benzodiazepine); haloperidol 2.5–5 mg orally or 5–10 mg IM, repeatable every 1–2 hours in serious psychotic aggression — check the QT first: QTc above 500 ms or a rise over 60 ms changes the drug; olanzapine 10 mg IM (2.5–5 mg frail elderly — never with a parenteral benzodiazepine without close respiratory monitoring); promethazine 50 mg IM as an adjunct.Doctor / Nurse
- Children: diazepam 0.1–0.2 mg/kg IV, max single dose 10 mg, slowly; lorazepam 0.05–0.1 mg/kg oral/IM, max 2 mg; weight (kg) ≈ (age + 4) × 2 for ages 1–10 when no weight is available. Promethazine is contraindicated under 2 years; haloperidol is not recommended under 12 years without specialist paediatric agreement. Acute dystonic reaction or oculogyric crisis: procyclidine 5–10 mg IV or IM — relief is dramatic and diagnostic.Doctor / Nurse
- If restraint is unavoidable: never prone, never with weight, a knee or a body across the chest, abdomen or neck — positional asphyxia is the mechanism of most restraint deaths. A minimum of five people, one to each limb and one whose sole responsibility is the head and airway (never given a limb to hold); time-limited to the injection, limbs released as sedation takes effect.
- Monitor after sedation: continuous oximetry and direct observation, full observations every 15 minutes to 1 hour, a complete set reviewed before every repeat dose, with oxygen, suction and a bag-valve-mask immediately available. The target is a calm, rousable patient (RASS 0 to −1), not an unconscious one. A struggling patient who suddenly goes quiet has either settled or stopped breathing — never assume the first.Doctor / Nurse
| Cause | First-line class |
|---|---|
| Alcohol / sedative withdrawal | Benzodiazepine — never an antipsychotic first |
| Stimulant toxicity | Benzodiazepine (IV diazepam settles BP and pulse too) |
| Primary psychosis / mania | Antipsychotic |
| Serotonin syndrome / NMS / anticholinergic | Benzodiazepine + stop the offending agent |
| Delirium in the elderly / dementia | Find and fix the cause; drugs last, lowest, singly |
| Cause unknown (no head injury / CO2 retention) | Benzodiazepine |
Refer / escalate
Call for help or transfer urgently for any agitated patient with a red flag you cannot resolve — hypoxaemia or a rising PaCO₂, temperature above 39°C, focal neurological signs, head injury or anticoagulation needing CT, suspected meningoencephalitis or non-convulsive status, an infant under 3 months, refractory withdrawal needing dexmedetomidine or airway capability, or any patient requiring IM ketamine or restraint beyond your monitoring capacity.
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