Key Facts

Psychiatric emergencies require rapid assessment and intervention to ensure safety. They encompass acute presentations across the spectrum of mental health conditions.

Epidemiology

Psychiatric emergencies account for approximately 5-10% of emergency department attendances. Self-harm is the most common (~200,000/year in England). Acute psychosis, severe agitation, and substance-related emergencies are also frequent.

Aetiology

• Acute psychosis: First episode, relapse of schizophrenia/bipolar, substance-induced
• Severe agitation/violence: Psychosis, intoxication, delirium, personality disorder, organic cause
• Self-harm/suicidal crisis: Depression, personality disorder, psychosis, substance misuse
• Catatonia: Psychotic disorders, mood disorders, autoimmune encephalitis, metabolic
• Pharmacological: NMS, serotonin syndrome, lithium toxicity

Pathophysiology

• Agitation: Sympathetic overdrive, dopaminergic excess (psychosis), GABAergic deficiency (alcohol/benzo withdrawal)
• Catatonia: GABA-A receptor dysfunction — explains response to benzodiazepines
• Delirium: Cholinergic deficit, dopaminergic excess, neuroinflammation

Acute Psychosis

• Delusions, hallucinations, disorganised behaviour, agitation
• May lack insight and refuse assessment/treatment
• Risk of harm to self or others

Severe Agitation/Violence

• Verbal aggression, threatening behaviour, physical violence
• May be due to psychosis, intoxication, delirium, personality disorder, pain
• Assess for organic cause: Hypoglycaemia, head injury, sepsis, intoxication

Catatonia

• Immobility, mutism, staring, posturing, waxy flexibility, negativism
• OR excited catatonia: Purposeless excessive motor activity
• Medical emergency — risk of dehydration, DVT, rhabdomyolysis

Red Flags

• Compromised airway, breathing, or circulation
• Signs of organic cause: Fever, focal neurology, new-onset confusion
• Extreme agitation with autonomic instability — consider NMS, serotonin syndrome, excited delirium
• Refusal to eat/drink — dehydration, renal failure risk

Bedside

• Observations: HR, BP, RR, SpO2, temperature, glucose — exclude organic cause
• MSE: Rapid mental state assessment
• Capacity assessment: Can the patient understand, retain, weigh, and communicate a decision?
• Risk assessment: Immediate risk to self and others

Bloods

• Glucose: Hypoglycaemia
• FBC, CRP, U&Es, LFTs: Infection, metabolic derangement
• Drug and alcohol screen: Intoxication/withdrawal
• CK: NMS, rhabdomyolysis (catatonia)
• TFTs, calcium: Organic causes of psychiatric presentation

Special Tests

• CT head: If new-onset confusion, focal neurology, head injury
• LP: If meningitis/encephalitis suspected
• ECG: Baseline and post-rapid tranquillisation

Non-pharmacological

• De-escalation: Calm voice, non-threatening posture, offer choices, listen, empathise, set clear boundaries
• Safe environment: Reduce stimuli, remove potential weapons, ensure exit route for staff
• 1:1 observation: If ongoing risk

Rapid Tranquillisation (NICE NG10)

Step 1 — Oral (if accepted):

• Lorazepam 1-2mg PO

Step 2 — IM (if oral refused/ineffective):

• Lorazepam 1-2mg IM, OR
• Haloperidol 5mg IM + promethazine 25-50mg IM
• Avoid haloperidol in Parkinson's, Lewy body dementia, prolonged QTc

Post-RT monitoring:

• Pulse, BP, RR, temperature, SpO2 every 15 minutes for ≥1 hour
• Flumazenil 200mcg IV available for benzodiazepine-related respiratory depression

Catatonia

• Lorazepam 1-2mg IM/IV — first-line; dramatic response expected within hours
• ECT: If refractory to benzodiazepines — highly effective
• Supportive care: IV fluids, DVT prophylaxis, nutritional support

Referral Criteria

• Crisis team or inpatient admission for ongoing risk
• MHA assessment if treatment refusal and meets criteria
• Section 136 assessment: Patient detained by police — assessment within 24 hours

• Outcomes depend on underlying condition and promptness of treatment
• Rapid tranquillisation: Generally safe with monitoring; risk of respiratory depression, oversedation, cardiovascular events
• Catatonia: Excellent response to lorazepam (~70-80%); ECT effective in refractory cases
• Post-emergency follow-up is essential to prevent recurrence

Mental Health Act Key Sections