Psychiatric emergencies

• Agitation and violence: The Agitated or Disturbed Patient | Medical Causes of Acute Disturbance | De-escalation and Restraint | Rapid Tranquillisation | After Rapid Tranquillisation | Acute Behavioural Disturbance
• Drug emergencies: Neuroleptic Malignant Syndrome | Serotonin Syndrome | NMS or Serotonin Syndrome? | Lithium Toxicity | Anticholinergic Toxicity | Psychiatric Drug Overdoses | Water Intoxication and Hyponatraemia
• Legal and practical: Refusing Treatment After Self-harm | Patients Who Want to Leave | Police, Places of Safety and Crisis Care
• Revision: Drug Reference Table | Spot the Diagnosis | Exam-style Scenarios | Key Points | Guidelines and Further Reading

🚨 Psychiatric emergencies — the agitated patient, the overdose who refuses treatment, the person trying to leave the emergency department, and the patient on psychiatric drugs who becomes hot, rigid or confused. Many "psychiatric" emergencies have a medical cause, and several drug reactions — neuroleptic malignant syndrome, serotonin syndrome, lithium toxicity — can kill if missed.
Your four questions for every patient: Is everyone safe right now (patient, staff, others)? Could this be medical (glucose, oxygen, head injury, infection, drugs, withdrawal)? Which legal framework applies (capacity, MCA, MHA, police powers)? What is the least restrictive way to manage this?

The Agitated or Disturbed Patient

• Safety first — your own safety and others'; don't see a potentially violent patient alone; know the exits; use alarms; remove potential weapons; involve security early if needed.
• Warning signs of violence — pacing, clenched fists, raised voice, threats, staring, invading personal space, intoxication, paranoia or command hallucinations, previous violence (the strongest predictor).
• Rapid assessment — is this delirium, intoxication, withdrawal, psychosis, mania, personality disorder, dementia, or a medical emergency? Check glucose, oxygen saturations, temperature, pupils, signs of head injury.
• Collateral information — notes, police, family, paramedics, GP; known diagnoses and care plans; advance statements.
• Approach — de-escalation first, then oral medication, then IM rapid tranquillisation if needed — the least restrictive option that keeps people safe.

Medical Causes of Acute Disturbance

• Always consider (especially with no psychiatric history, older age, confusion, fluctuating consciousness or abnormal observations):
  • Hypoglycaemia — check glucose in every agitated or confused patient.
  • Hypoxia — pneumonia, PE, asthma, COPD.
  • Delirium — sepsis, UTI, drugs, electrolytes, urinary retention, constipation, pain.
  • Head injury — intracranial bleed (subdural in older people and heavy drinkers).
  • Intoxication — alcohol, stimulants, synthetic cannabinoids, hallucinogens.
  • Withdrawal — alcohol (DTs), benzodiazepines, GHB.
  • Encephalitis — HSV, autoimmune; meningitis.
  • Post-ictal state or non-convulsive status epilepticus.
  • Thyroid storm, hypercalcaemia, hyponatraemia, hepatic or uraemic encephalopathy.
  • Drug reactions — NMS, serotonin syndrome, anticholinergic toxicity, lithium toxicity, steroids.
  • Stroke (especially posterior circulation or non-dominant parietal lesions).
• Tests — glucose, observations including temperature, FBC, U&E, calcium, LFTs, CRP, CK, blood gas, urine drug screen, alcohol level, ECG; CT head if injury, focal signs or unexplained reduced consciousness; LP if encephalitis or meningitis possible.

⚠️ Safety Pearl: "Agitated, known psychiatric patient" is a dangerous label. Check the glucose, temperature and oxygen saturations in every agitated patient — hypoglycaemia, hypoxia, sepsis and head injury are easily missed in people with mental illness.

De-escalation and Restraint

• De-escalation (NICE NG10):
  • One person leads the conversation; calm, slow, clear speech; non-threatening posture; respect personal space.
  • Listen and acknowledge feelings ("I can see you're very frustrated"); find out what they want; offer choices.
  • Reduce stimulation — quiet room, fewer people; offer food, drink, a phone call.
  • Avoid arguing, sudden movements, or making promises you can't keep.
• Oral medication — offer if de-escalation alone isn't enough: e.g. lorazepam, promethazine, or the person's usual antipsychotic (e.g. olanzapine, haloperidol in people already established on antipsychotics).
• Physical restraint — last resort, by trained staff, for the shortest time, proportionate:
  • Avoid the prone (face-down) position and any pressure on the chest, neck or abdomen — positional asphyxia and cardiac arrest.
  • One staff member protects the head and airway and monitors breathing and colour.
  • Legal basis — Mental Health Act (detained patients), Mental Capacity Act (lacks capacity, best interests, proportionate), or common law (immediate risk to others).
  • Record and report every use of force (Mental Health Units (Use of Force) Act 2018).
• Seclusion — in mental health units only, with strict safeguards and regular review.
• Debrief the patient and staff afterwards.

Rapid Tranquillisation

• Rapid tranquillisation (RT) — medication given by injection (usually IM) when oral medication isn't possible or hasn't worked and urgent sedation is needed to reduce risk. Aim: calm, not unconscious.
• Before RT — consider the legal basis, physical health (cardiac history, ECG if available, recent drugs or alcohol), previous response, advance statements, pregnancy, age.
• Options (NICE NG10 — follow local protocol):
  • IM lorazepam (e.g. 1–2 mg) — especially if no ECG, cardiac disease, antipsychotic-naive, or stimulant intoxication.
  • IM haloperidol with IM promethazine (e.g. haloperidol 5 mg plus promethazine 25–50 mg) — check an ECG first if possible (QT); promethazine reduces the risk of acute dystonia.
  • IM olanzapine — used in some protocols (don't give IM olanzapine within 1 hour of IM lorazepam — risk of respiratory depression and hypotension).
  • If partial response — repeat or switch to the other option after an adequate interval.
• Special groups:
  • Older people and dementia — low doses; prefer lorazepam; avoid antipsychotics in Lewy body dementia and Parkinson's.
  • Intoxication — alcohol plus benzodiazepines risks respiratory depression; stimulants — benzodiazepines preferred.
  • Pregnancy — seek senior advice; avoid prolonged restraint.
  • Children and young people — IM lorazepam is preferred.
• Have available — flumazenil (benzodiazepine reversal), procyclidine (dystonia), oxygen, suction, bag-valve-mask, defibrillator.

After Rapid Tranquillisation

• Monitor — pulse, BP, respiratory rate, oxygen saturations, temperature, hydration and level of consciousness:
  • At least every hour until there are no further concerns.
  • Every 15 minutes if the BNF maximum dose has been exceeded, the patient is asleep or sedated, has taken alcohol or drugs, has a physical illness, or has been restrained.
  • If the patient refuses observations, observe breathing and colour from a distance and record it.
• Complications to watch for:
  • Respiratory depression (benzodiazepines) — oxygen, airway support; flumazenil if respiratory rate under 10.
  • Acute dystonia (haloperidol) — procyclidine IM or IV.
  • Hypotension, arrhythmias, QT prolongation (ECG once possible).
  • NMS — fever, rigidity, confusion (CK).
  • Over-sedation and aspiration — recovery position.
  • Injuries from restraint; rhabdomyolysis (CK).
• Review — once settled, assess mental state and physical health, look for the cause, and plan care.

Acute Behavioural Disturbance

• What it is: A medical emergency with extreme agitation, often from stimulant intoxication (cocaine, methamphetamine, synthetic cannabinoids) or severe mental illness, sometimes after prolonged struggling or restraint (previously called "excited delirium"). Risk of sudden cardiac arrest.
• Features — extreme agitation and aggression, apparent great strength, insensitivity to pain, hyperthermia, profuse sweating, tachycardia, confusion, shouting, removing clothing, continued struggling.
• Management (RCEM guidance):
  • Treat as a medical emergency in the emergency department (not a police cell).
  • Minimise restraint — avoid prone restraint; monitor airway and breathing.
  • Early sedation — IM or IV benzodiazepines; ketamine (IM) by experienced clinicians in some departments.
  • Cooling, IV fluids, oxygen.
  • Check — glucose, blood gas (acidosis), potassium, CK (rhabdomyolysis), temperature, ECG.
  • Prepare for cardiac arrest; ICU involvement.

Neuroleptic Malignant Syndrome

• What it is: A rare, life-threatening reaction to dopamine blockade — any antipsychotic (more with high-potency, IM, rapid dose increases, depot), metoclopramide, prochlorperazine — or to stopping dopaminergic drugs (levodopa in Parkinson's disease).
• Onset — usually over days (often within the first 2 weeks of starting or increasing the drug), but can happen at any time.
• Features:
  • Fever (hyperthermia).
  • "Lead-pipe" rigidity (generalised), tremor.
  • Altered mental state — confusion, drowsiness, mutism, catatonia.
  • Autonomic instability — tachycardia, labile BP, sweating, incontinence.
  • Slow reflexes (bradyreflexia).
• Tests — very high CK, raised white cells, raised LFTs, AKI (myoglobinuria), low iron, metabolic acidosis, electrolytes; exclude sepsis, meningitis and encephalitis.
• Treatment:
  • Stop the antipsychotic (restart levodopa if withdrawal is the cause).
  • Supportive care — IV fluids (protect the kidneys), cooling, VTE prophylaxis; HDU or ICU.
  • Benzodiazepines (lorazepam) for agitation and rigidity.
  • Dantrolene (muscle relaxant) and/or bromocriptine (dopamine agonist) in severe cases; ECT for refractory cases.
• Complications — rhabdomyolysis, AKI, aspiration pneumonia, respiratory failure, arrhythmias, DIC; mortality about 5–10%.
• Restarting antipsychotics — wait at least 2 weeks after recovery; use a low-potency drug at a low dose, increasing slowly with monitoring.

Serotonin Syndrome

• What it is: Excess serotonin activity — usually from combinations of serotonergic drugs, an overdose, or a dose increase.
• Culprit drugs — SSRIs, SNRIs, MAOIs (especially with other serotonergic drugs), TCAs (clomipramine), tramadol, pethidine, fentanyl, methadone, triptans, linezolid, lithium, ondansetron, St John's wort, MDMA, cocaine, amphetamines.
• Onset — rapid (within hours — usually within 24 hours of the change).
• Features (triad):
  • Neuromuscular excitation — clonus (inducible, spontaneous, ocular — the key sign), hyperreflexia, tremor, myoclonus, rigidity (more in the legs).
  • Autonomic — hyperthermia, sweating, tachycardia, hypertension, dilated pupils, diarrhoea, flushing.
  • Mental state — agitation, anxiety, confusion.
• Hunter criteria (diagnosis, with a serotonergic drug) — spontaneous clonus; or inducible or ocular clonus with agitation or sweating; or tremor with hyperreflexia; or hypertonia with temperature over 38 °C plus ocular or inducible clonus.
• Treatment:
  • Stop all serotonergic drugs.
  • Supportive — IV fluids, cooling, oxygen; most mild cases settle within 24 hours.
  • Benzodiazepines for agitation, tremor and muscle activity.
  • Cyproheptadine (oral or via nasogastric tube — a serotonin antagonist) for moderate cases.
  • Severe (temperature over 41 °C, rigidity) — ICU: sedation, paralysis and ventilation; avoid physical restraint (worsens hyperthermia and acidosis).
• Prevention — check for interactions; allow washout periods when switching (e.g. 2 weeks after stopping an MAOI, 5 weeks after stopping fluoxetine before starting an MAOI).

NMS or Serotonin Syndrome?

• Also consider — malignant hyperthermia (after anaesthetic agents), anticholinergic toxicity (dry, hot skin, no clonus), sepsis, meningitis or encephalitis, heat stroke, stimulant toxicity, thyroid storm, malignant catatonia.

💡 Clinical Pearl: To tell NMS from serotonin syndrome, look at the legs: serotonin syndrome gives clonus and brisk reflexes (especially at the ankles) and develops over hours; NMS gives lead-pipe rigidity with slow reflexes and develops over days.

Lithium Toxicity

• Causes — dehydration (vomiting, diarrhoea, hot weather, infection), AKI, interacting drugs (NSAIDs, ACE inhibitors, ARBs, thiazides), overdose (acute, or acute-on-chronic), dose increases, low-salt diet.
• Features (levels usually over 1.5 mmol/L, but toxicity can occur at "normal" levels — especially in older people and chronic toxicity):
  • Mild — nausea, vomiting, diarrhoea, coarse tremor, drowsiness.
  • Moderate — ataxia, slurred speech, confusion, muscle twitching, increased tone.
  • Severe — hyperreflexia, myoclonus, seizures, coma, arrhythmias (bradycardia, QT), AKI.
• Chronic toxicity is more dangerous than acute overdose at the same level (lithium is already in the brain).
• Tests — lithium level (repeat every 6–12 hours), U&E, calcium, TFTs, ECG, glucose; time of last dose.
• Treatment (TOXBASE):
  • Stop lithium and interacting drugs.
  • IV 0.9% sodium chloride — restore fluid and sodium balance; monitor urine output and sodium (watch for nephrogenic diabetes insipidus).
  • Activated charcoal doesn't bind lithium; whole bowel irrigation for large overdoses of modified-release tablets (specialist).
  • Haemodialysis — severe neurological features (confusion, seizures, coma), very high levels, kidney failure, or failure to improve; levels may rebound afterwards.
• Long-term — neurological damage (cerebellar) can persist (SILENT — syndrome of irreversible lithium-effectuated neurotoxicity).

Anticholinergic Toxicity

• Causes — TCAs, antihistamines (diphenhydramine, promethazine), antipsychotics (chlorpromazine, clozapine, olanzapine), procyclidine, hyoscine, oxybutynin, some plants (deadly nightshade, Jimson weed); older people on multiple anticholinergic drugs (anticholinergic burden).
• Features — "hot as a hare" (fever), "dry as a bone" (dry skin and mouth, no sweating), "red as a beet" (flushing), "blind as a bat" (dilated pupils, blurred vision), "mad as a hatter" (delirium, hallucinations, picking at things), "full as a flask" (urinary retention); tachycardia, reduced bowel sounds, seizures.
• Key difference from serotonin syndrome — dry skin and no clonus.
• Treatment — stop the drug; supportive care, IV fluids, cooling, catheter for retention; benzodiazepines for agitation; physostigmine (specialist advice, rarely used — avoid with TCA overdose); ECG monitoring.

Psychiatric Drug Overdoses

• Every overdose — ABCDE, glucose, ECG, paracetamol and salicylate levels (co-ingestion is common), U&E; activated charcoal within 1 hour if appropriate and the airway is safe; psychosocial assessment once medically fit.

Water Intoxication and Hyponatraemia

• Psychogenic (primary) polydipsia — compulsive water drinking, especially in schizophrenia (sometimes many litres a day): dilute urine, hyponatraemia (confusion, vomiting, seizures, coma).
• Drug-induced hyponatraemia (SIADH) — SSRIs, SNRIs, mirtazapine, carbamazepine, oxcarbazepine, antipsychotics; MDMA. Older people, women, low body weight and diuretics increase the risk.
• Management:
  • Fluid restriction (polydipsia, SIADH); stop or change the drug.
  • Severe symptoms (seizures, reduced consciousness) — hypertonic (2.7–3%) saline boluses with specialist and ICU input.
  • Correct sodium slowly — no more than about 10 mmol/L in 24 hours — to avoid osmotic demyelination syndrome (especially in polydipsia, where water diuresis can cause rapid overcorrection once drinking stops).
  • Clozapine may reduce polydipsia in schizophrenia; behavioural approaches; weigh daily.

Refusing Treatment After Self-harm

• Common scenario — a person who has taken an overdose refuses blood tests or acetylcysteine.
• Assess capacity for this specific decision (understand, retain, weigh, communicate) — intoxication, severe depression, hopelessness or psychosis can impair the ability to weigh information; involve a senior and liaison psychiatry quickly.
• Lacks capacity — treat in their best interests under the Mental Capacity Act, using the least restrictive approach (and restraint if necessary and proportionate); document carefully.
• Has capacity — a capacitous adult can refuse treatment even if this may lead to death; respect this, but:
  • Keep talking — explore reasons, offer support, involve family (with consent), keep offering treatment.
  • Consider whether a Mental Health Act assessment is needed for an underlying mental disorder (the MHA can't be used to force treatment of an overdose in someone not detained).
  • Advance decisions refusing treatment after self-harm — check validity carefully and get senior and legal advice.
• Emergency — if there's no time to assess capacity and life is at risk, treat (common law / MCA section 5) and assess as soon as possible.
• Under 18s — see the Safeguarding chapter (Gillick competence, parental consent, court).

Patients Who Want to Leave

• Emergency department (not yet admitted):
  • Section 5(2) can't be used (not an inpatient).
  • Lacks capacity to decide to leave and at risk — the MCA allows proportionate steps (including restraint) to prevent harm in their best interests while arranging assessment.
  • Has capacity — can leave; if a mental disorder puts them at serious risk, request an urgent MHA assessment; if they leave, inform the police (and others at risk) as appropriate.
  • Consider calling the police if they leave and are at serious risk (they may use section 136 in a public place).
• Medical or surgical inpatient (informal) — section 5(2) by the doctor in charge (or their nominated deputy) for up to 72 hours, pending MHA assessment, if there is a mental disorder and risk. If the problem is purely physical and they lack capacity, use the MCA (and DoLS if needed).
• Psychiatric inpatient (informal) — section 5(4) by a nurse (6 hours) then 5(2).
• Detained patient who leaves — absent without leave (AWOL) — the hospital can return them; inform the police if at risk.
• Document — capacity assessment, risk, discussions, and the legal basis for any action.

Police, Places of Safety and Crisis Care

• Section 136 — police can take a person who appears to have a mental disorder from a public place to a place of safety (health-based place of safety or the emergency department); up to 24 hours for assessment. Police cells are not used for under 18s, and the 2025 Act will end their use for adults.
• Section 135 — magistrate's warrant to enter private premises.
• "Right Care, Right Person" — police in England are reducing their attendance at health-related calls (e.g. walk-outs from hospital, welfare checks) unless there is a risk to life or of serious harm — health services need clear plans for patients who leave.
• Crisis services — NHS 111 "option 2" for mental health crisis, crisis resolution and home treatment teams, crisis cafés and safe havens, liaison psychiatry in the emergency department.
• Voluntary support — Samaritans (116 123), SHOUT (text 85258), Papyrus (young people), CALM (men).

Drug Reference Table

Spot the Diagnosis

Exam-style Scenarios

1. A 30-year-old man with schizophrenia is shouting and threatening staff on a psychiatric ward. De-escalation and oral medication have failed. He has no ECG on record.
Answer: Rapid tranquillisation — IM lorazepam (no ECG, so avoid haloperidol).

• Safe restraint by trained staff, avoiding the prone position.
• Monitor pulse, BP, respiratory rate, oxygen saturations, temperature and consciousness (every 15 minutes if sedated).
• Flumazenil available; review mental state and debrief afterwards.

2. A 45-year-old woman started on haloperidol 10 days ago is confused, febrile (39.6 °C) and rigid, with a BP of 180/110 and heart rate of 130. CK 32,000; creatinine raised.
Answer: Neuroleptic malignant syndrome with rhabdomyolysis and AKI.

• Stop haloperidol; IV fluids; cooling; HDU or ICU.
• Lorazepam; dantrolene and/or bromocriptine if severe.
• Exclude sepsis and encephalitis; VTE prophylaxis; delay restarting antipsychotics at least 2 weeks.

3. A 38-year-old woman on fluoxetine was given tramadol for back pain yesterday. She is agitated, sweating, has dilated pupils, a temperature of 38.4 °C and inducible ankle clonus.
Answer: Serotonin syndrome.

• Stop fluoxetine and tramadol (fluoxetine's long half-life prolongs the risk).
• IV fluids, cooling, benzodiazepines; cyproheptadine if moderate.
• ICU if hyperthermia over 41 °C or rigidity; non-serotonergic analgesia.

4. A 22-year-old woman took 40 paracetamol tablets 6 hours ago. She refuses treatment, saying she wants to die. She says she knows she might die but "nothing matters anymore".
Answer: Assess capacity — severe hopelessness may prevent her from weighing the information.

• Urgent senior and liaison psychiatry involvement; take bloods and start acetylcysteine if she lacks capacity (MCA, best interests).
• If she has capacity — keep engaging, offer treatment repeatedly, involve family with consent, consider an MHA assessment.
• Document the capacity assessment and reasoning in detail.

5. A 70-year-old man on lithium was started on bendroflumethiazide for hypertension 2 weeks ago. He is confused and unsteady with a coarse tremor. Lithium level 2.1 mmol/L.
Answer: Chronic lithium toxicity (thiazide interaction).

• Stop lithium and the thiazide; IV 0.9% saline; monitor U&E and levels every 6–12 hours; ECG.
• Discuss with renal — haemodialysis for severe neurological toxicity or kidney failure.
• Review mood stabiliser and antihypertensive choices with psychiatry.

Key Points

• Check glucose, oxygen, temperature and look for head injury in every agitated patient.
• De-escalation first, then oral medication, then IM rapid tranquillisation.
• Avoid prone restraint — positional asphyxia.
• RT: IM lorazepam, or IM haloperidol with promethazine (ECG first); no IM olanzapine within 1 hour of IM lorazepam.
• After RT: monitor at least hourly; every 15 minutes if sedated, intoxicated, restrained or high doses.
• Acute behavioural disturbance is a medical emergency — sedate early, cool, check CK; risk of cardiac arrest.
• NMS: days; fever, lead-pipe rigidity, slow reflexes, confusion, very high CK — stop antipsychotic, fluids, dantrolene or bromocriptine.
• Serotonin syndrome: hours; clonus, hyperreflexia, dilated pupils, diarrhoea — stop drugs, benzodiazepines, cyproheptadine.
• Lithium toxicity: coarse tremor, ataxia, confusion — stop lithium, IV saline, haemodialysis if severe; charcoal doesn't work.
• Anticholinergic toxicity: hot, dry, red, dilated pupils, delirium, urinary retention.
• TCA overdose: wide QRS and seizures — IV sodium bicarbonate.
• Correct hyponatraemia slowly (no more than about 10 mmol/L in 24 hours).
• Overdose refusing treatment: assess capacity; treat under the MCA if lacking; respect capacitous refusal but keep engaging.
• Section 5(2) can't be used in the emergency department.

Guidelines and Further Reading

• NICE NG10: Violence and aggression — short-term management in mental health, health and community settings
• Royal College of Emergency Medicine: Acute behavioural disturbance guidance
• Royal College of Psychiatrists / RCEM: Mental health in emergency departments toolkit
• TOXBASE: Lithium, tricyclic antidepressants, SSRIs, antipsychotics
• Maudsley Prescribing Guidelines in Psychiatry (NMS, serotonin syndrome, rapid tranquillisation)
• Mental Capacity Act 2005 and Mental Health Act 1983 Codes of Practice
• Mental Health Units (Use of Force) Act 2018 statutory guidance
• National Partnership Agreement: Right Care, Right Person
• BNF — for current doses