About This Page
This is a clinician-written, evidence-based guide aligned to the MCC Examination Objectives. It is structured by clinical presentation — the way the MCCQE tests and the way patients actually present. Management reflects current Canadian guidelines (CMA, CFPC, CPS). Always cross-reference with institutional protocols and clinical judgment.
The Bottom Line
- Agitation is a symptom, not a diagnosis: hypoxia, hypoglycaemia, delirium, intoxication, withdrawal, pain, head injury, psychosis, and mania must be considered
- Immediate priorities are safety, ABCs, glucose, vitals, low-stimulus environment, verbal de-escalation, and least restrictive intervention
- Benzodiazepines are often preferred for stimulant intoxication, alcohol/benzodiazepine withdrawal, and undifferentiated severe agitation
- Antipsychotics are useful for psychosis/mania but require QT/EPS awareness
- Physical restraint is a last resort, time-limited, closely monitored intervention
Approach to the Presentation
Agitation and aggression can escalate quickly and the first obligation is safety. Use a trauma-informed approach: introduce yourself, maintain distance, offer choices, reduce stimulation, remove audience, and avoid power struggles. While engaging, scan for medical causes: abnormal vitals, hypoxia, hypoglycaemia, fever, head injury, intoxication, withdrawal, pain, urinary retention, infection, delirium, mania, psychosis, and medication effects. Emergency medication or restraint is justified only when imminent risk persists and less restrictive measures fail or are impossible.
Differential Diagnosis
| diagnosis | likelihood | key features | distinguishing test |
|---|---|---|---|
| Delirium / medical illness | must-not-miss | Acute fluctuating attention, disorientation, altered consciousness, fever, hypoxia, sepsis, urinary retention, pain, metabolic disturbance | Glucose, vitals, CAM/4AT, CBC/electrolytes/renal tests, infection search, medication review |
| Hypoglycaemia / hypoxia / head injury | must-not-miss | Agitation, confusion, combativeness, reduced consciousness, trauma signs, intoxication history | Point-of-care glucose, oxygen saturation/ABG, trauma exam, CT head if indicated |
| Stimulant intoxication or sympathomimetic toxidrome | must-not-miss | Agitation, paranoia, mydriasis, diaphoresis, tachycardia, hypertension, hyperthermia, chest pain, seizures | Clinical toxidrome; ECG, CK, renal function, troponin if chest pain |
| Alcohol or benzodiazepine withdrawal | must-not-miss | Tremor, diaphoresis, tachycardia, hypertension, hallucinations, seizure risk, delirium | History, CIWA-Ar when appropriate, electrolytes |
| Psychosis with persecutory delusions or command hallucinations | common | Threat perception, responding to voices, disorganised behaviour, poor insight, fear-driven aggression | Mental status exam, collateral, medical/substance exclusion |
| Mania / mixed state | common | Reduced need for sleep, increased energy, pressured speech, irritability, grandiosity, impulsivity | Mood history, collateral, mental status exam |
| Personality disorder crisis / trauma response | common | Interpersonal trigger, abandonment fear, affective instability, dissociation, self-harm threats | Longitudinal history; assess acute risk |
| Akathisia or medication reaction | less common | Inner restlessness after antipsychotic/antiemetic initiation or dose increase; pacing, inability to sit still | Medication timeline |
| Dementia with behavioural symptoms | less common | Older adult, cognitive impairment, environmental trigger, pain, infection, constipation, caregiver stress | Collateral, cognitive baseline, delirium screen, medication review |
Red Flags & Key History
Symptoms
Weapon, imminent violence, command hallucinations, persecutory delusions, or inability to be redirected
Fever, hypoxia, head trauma, seizure, severe headache, chest pain, or reduced consciousness
Hyperthermia, severe rigidity/clonus, diaphoresis, or severe autonomic instability
Alcohol/benzodiazepine withdrawal history or recent abrupt cessation
Pregnancy, older adult, intellectual disability, autism, dementia, or communication barrier
Triggering event, pain, fear, overcrowding, perceived threat
Signs
Abnormal vitals, hypoxia, hypoglycaemia, fever, trauma signs
Mydriasis/diaphoresis/hyperthermia or tremor/autonomic withdrawal signs
Disorientation or inattention — delirium
Pressured speech, flight of ideas, grandiosity — mania
EPS, dystonia, akathisia after dopamine-blocking medication
Approach to Investigation
First-line
Point-of-care glucose, oxygen saturation, full vitalsRapidly reversible causes of agitation
Focused safety and medical examTrauma, head injury, infection, pain, urinary retention, toxidrome, neurological signs, pregnancy, and withdrawal signs
Collateral and recordsBaseline mental state, medications, substances, violence risk, triggers, allergies, previous effective de-escalation or medications
ECG when medication or tox riskQTc, QRS widening, ischemia, arrhythmia before/after antipsychotics or overdose when feasible
Second-line
Labs and imaging guided by presentationCBC, electrolytes, creatinine, CK, LFTs, toxicology, ethanol, pregnancy test, infection work-up, CT head if indicated
Formal psychiatric assessment after calmingRisk, psychosis, mood, trauma, substance use, capacity, safeguarding, and disposition
Specialist
Psychiatry / crisis teamPsychosis, mania, high suicide/violence risk, involuntary assessment, or complex disposition
ICU / toxicology / internal medicineHyperthermia, severe toxidrome, delirium, rhabdomyolysis, seizures, respiratory compromise, or medical instability
Management Principles
Emergency Care BC Agitated Patient Guidance + CADTH rapid tranquillisation evidence review + CAMH resources1
Verbal and environmental de-escalation
- Use calm tone, short sentences, non-threatening posture, personal space, clear limits, and choices
- Reduce noise/crowding, remove potential weapons, offer food/fluids/blanket, address pain, nicotine withdrawal, and fear where safe
2
Medication when risk is imminent
- Choose based on likely cause: benzodiazepines for stimulant intoxication or alcohol/benzodiazepine withdrawal; antipsychotic for psychosis/mania
- Common agents include lorazepam, haloperidol, olanzapine, or droperidol depending on local protocols and risks
- Monitor airway, respiratory rate, oxygen saturation, BP, QT risk, and level of consciousness
3
Physical restraint
- Last resort for imminent harm after less restrictive measures fail or cannot be attempted safely
- Use trained team, shortest duration, frequent reassessment, airway-safe positioning, circulation checks, and documentation
Complications & Pitfalls
- Calling it psychiatric too early: Hypoxia, hypoglycaemia, delirium, head injury, and sepsis can present as aggression.
- Restraint harm: Restraint increases risk of asphyxia, rhabdomyolysis, trauma, and psychological harm.
- Medication mismatch: Antipsychotic monotherapy is inadequate for alcohol/benzodiazepine withdrawal seizures.
- No reassessment: After calming, the diagnostic assessment often changes substantially.
MCCQE1 Exam Tips
- 1First step in acute agitation: safety + de-escalation + ABCs/glucose/vitals
- 2Delirium clues: acute onset, fluctuating attention, altered consciousness, abnormal vitals
- 3Stimulant intoxication: benzodiazepines and cooling are high-yield; check CK and temperature if severe
- 4Alcohol withdrawal agitation: benzodiazepines, not haloperidol alone
- 5Physical restraint is last resort and requires close monitoring/documentation
- 6Use least restrictive care consistent with safety
practicetest your knowledge on agitation & aggression (acute behavioural disturbance)Apply what you've learnt with MCCQE1-style questions from the iatroX Q-Bank — psychiatric and beyond.
open q-bank