Cocaine Toxicity

Quick Answer: Cocaine toxicity is a medical emergency requiring immediate supportive care. Benzodiazepines are first-line for agitation, hypertension, tachycardia, and seizures. Nitroglycerin for myocardial ischaemia; phentolamine for severe hypertension unresponsive to benzodiazepines. Beta-blockers are CONTRAINDICATED due to risk of unopposed alpha-mediated vasoconstriction. Manage complications: hyperthermia (active cooling), rhabdomyolysis (aggressive IV fluids), excited delirium (benzodiazepines ± rapid sequence intubation).

ACEM Exam Focus

Primary Exam: Pharmacology of cocaine (mechanism of action, metabolism, pharmacokinetics), autonomic nervous system effects (sympathetic vs parasympathetic), cardiovascular physiology (vasoconstriction, tachyarrhythmias).

Fellowship Written: Management of acute cocaine toxicity, cardiovascular complications, excited delirium syndrome, cocaine-associated chest pain evaluation, drug interactions (cocaine + alcohol = cocaethylene), contraindicated medications (beta-blockers, procainamide).

Fellowship OSCE: Resuscitation station (agitated hypertensive patient), communication station (agitated intoxicated patient), procedure station (rapid sequence intubation in excited delirium).

Critical Knowledge: Benzodiazepines as universal antidote for cocaine toxicity, contraindication of beta-blockers, diagnosis and management of excited delirium, cocaine-associated chest pain workup, hyperthermia and rhabdomyolysis management.

Key Points

• Cocaine blocks presynaptic catecholamine reuptake (noradrenaline, dopamine, serotonin) causing sympathomimetic toxicity [PMID: 30185112]
• Benzodiazepines are first-line for all manifestations: agitation, hypertension, tachycardia, seizures [PMID: 22608914]
• Beta-blockers (including labetalol) are contraindicated due to risk of unopposed alpha-mediated vasoconstriction [PMID: 28743204]
• Cocaine-associated chest pain: rule out MI with serial troponin, ECG, observation for 9-12 hours [PMID: 10480473]
• Excited delirium syndrome: hyperagitation, hyperthermia, delirium, akathisia; high mortality if not rapidly controlled [PMID: 19391715]
• Cocaine + alcohol forms cocaethylene with prolonged euphoria and increased cardiotoxicity [PMID: 2846216]
• Pregnancy: Cocaine crosses placenta causing placental abruption, preterm labour, fetal distress [PMID: 12736467]

Epidemiology

Global and Australian Context

Prevalence: Cocaine remains one of the most commonly used illicit drugs worldwide. In Australia, recent use (past 12 months) was 2.1% of the population aged 14+ in 2022 [PMID: 38206745].

Emergency Department Presentations:

• Cocaine-related ED visits: 8-10 per 10,000 population annually in urban centres [PMID: 30185112]
• Chest pain accounts for 40-57% of cocaine-related ED presentations [PMID: 10480473]
• Acute toxicity with severe cardiovascular or neurological complications: 5-8% of presentations [PMID: 22608914]

Age and Gender Distribution:

• Peak age group: 20-40 years
• Male predominance: 65-75% of acute toxicity cases [PMID: 30185112]
• Female users have higher risk of placental complications during pregnancy [PMID: 12736467]

Mortality:

• Acute cocaine toxicity mortality: 0.7-2.3% [PMID: 22608914]
• Cocaine-associated myocardial infarction mortality: 4-6% [PMID: 9607769]
• Excited delirium syndrome mortality: 8-15% without appropriate management [PMID: 19391715]

Time Trends

• Peak ED presentations on weekends and evenings (Friday-Saturday, 1800-0200 hours) [PMID: 30185112]
• Seasonal variation: Increased presentations during warmer months due to enhanced heat dissipation impairment [PMID: 22608914]
• Polydrug use: 60-80% of patients have co-ingestants (alcohol, benzodiazepines, opioids, amphetamines) [PMID: 2846216]

Pathophysiology

Pharmacokinetics

Chemical Structure: Benzoylmethylecgonine, a tropane alkaloid derived from Erythroxylum coca plant.

Routes of Administration and Pharmacokinetics:

• Distribution: Volume of distribution 1.5-2.5 L/kg; rapidly crosses blood-brain barrier [PMID: 30185112]
• Metabolism: Hepatic hydrolysis by cholinesterase; primary metabolites: ecgonine methyl ester, benzoylecgonine (urine detection marker, 2-4 days) [PMID: 2846216]
• Elimination: Renal (1-5% unchanged); urine pH affects elimination (alkalinisation prolongs effect) [PMID: 30185112]
• Cocaethylene: Cocaine + alcohol metabolised by liver to form cocaethylene (half-life 3-5 hours), with more potent cardiotoxic effects than cocaine alone [PMID: 2846216]

Mechanism of Action

Primary Mechanisms:

1. Presynaptic Catecholamine Reuptake Inhibition: Blocks reuptake of noradrenaline, dopamine, and serotonin in synaptic cleft, increasing synaptic concentrations [PMID: 30185112]
2. Voltage-Gated Sodium Channel Blockade: Local anaesthetic effect on cardiac conduction system [PMID: 28743204]
3. Central Nervous System Stimulation: Dopamine reward pathway (mesolimbic system) causing euphoria and dependence [PMID: 30185112]

Sympathetic Overdrive Effects:

• Increased noradrenaline: Vasoconstriction, tachycardia, hypertension, mydriasis
• Increased dopamine: Euphoria, agitation, psychosis
• Increased serotonin: Mood alteration, hyperthermia

Cardiovascular Effects:

• Tachycardia: Direct sympathetic stimulation and reflex tachycardia from vasoconstriction
• Hypertension: Alpha-1 mediated systemic vasoconstriction
• Coronary vasoconstriction: Alpha-mediated coronary artery spasm, reducing myocardial oxygen supply [PMID: 9607769]
• Increased myocardial oxygen demand: Tachycardia, hypertension, increased contractility
• Arrhythmogenesis: Sodium channel blockade causing prolonged QRS, QT interval; catecholamine surge causing ventricular tachyarrhythmias [PMID: 28743204]

Neurological Effects:

• Cerebral vasoconstriction: Increased risk of ischaemic stroke, intracerebral haemorrhage
• Seizures: Lowered seizure threshold due to catecholamine surge
• Hyperthermia: Impaired thermoregulation, increased heat production from muscle activity

Pathophysiology of Specific Complications

Cocaine-Associated Myocardial Ischaemia/Infarction:

• Coronary vasoconstriction (alpha-mediated) [PMID: 9607769]
• Accelerated atherosclerosis (chronic use) [PMID: 10480473]
• Thrombogenesis: Increased platelet aggregation, prothrombotic state [PMID: 9607769]
• Increased myocardial oxygen demand
• Onset within 60 minutes of use, but risk persists for 24 hours

Cocaine-Induced Aortic Dissection:

• Severe hypertension causing shear stress on aortic wall
• Pre-existing hypertension, connective tissue disorders increase risk
• Peak incidence: 30-50 years, younger than typical aortic dissection population [PMID: 17598800]

Excited Delirium Syndrome:

• Sympathetic storm: Massive catecholamine surge
• Dopaminergic dysregulation in limbic system
• Impaired thermoregulation: Severe hyperthermia above 40°C [PMID: 19391715]
• Rhabdomyolysis: Muscle hyperactivity, direct myotoxicity
• Autonomic instability: Labile blood pressure, heart rate
• Acidosis: Lactic acidosis from muscle breakdown and seizures

Rhabdomyolysis:

• Direct myotoxicity: Cocaine-induced muscle membrane damage
• Prolonged muscle activity: Seizures, agitation, hyperthermia
• Compressive myopathy: Prolonged immobilisation during coma
• Risk of acute kidney injury: Myoglobinuria, hypovolaemia [PMID: 22608914]

Clinical Features

History Taking

Essential History Components:

• Route and timing of cocaine use (last dose)
• Quantity used (estimated amount)
• Polydrug use: Alcohol, benzodiazepines, opioids, amphetamines
• Intended use: Recreational vs chronic dependency
• Previous reactions to cocaine or other stimulants
• Medical history: Hypertension, coronary artery disease, seizures, psychiatric illness
• Medications: Beta-blockers, antidepressants, antipsychotics
• Pregnancy status (women of childbearing age)
• Current symptoms: Chest pain, palpitations, dyspnoea, headache, seizures, abdominal pain

Red Flag Historical Features:

• Chest pain with radiating symptoms
• Sudden onset severe headache ("thunderclap")
• Focal neurological deficits
• Severe tearing chest/back pain (aortic dissection)
• Seizure activity or loss of consciousness
• Hyperthermia or diaphoresis
• Agitation or psychosis with violent behaviour

Physical Examination

General Assessment:

• Level of consciousness: Glasgow Coma Scale
• Agitation, restlessness, psychotic behaviour
• Diaphoresis, mydriasis (pupillary dilation)
• Signs of trauma (violence, accidents)

Cardiovascular Examination:

• Heart rate: Tachycardia (HR above 100), bradycardia (late toxicity)
• Blood pressure: Hypertension (SBP above 160), hypotension (decompensated shock)
• Cardiac auscultation: Gallops, murmurs, pericardial rub
• Peripheral pulses: Pulses alternans, unequal pulses (aortic dissection)
• Jugular venous pressure: Elevated in cardiac failure

Respiratory Examination:

• Respiratory rate: Tachypnoea (RR above 20)
• Breath sounds: Crackles (pulmonary oedema), wheeze (bronchospasm)
• Oxygen saturations: May be desaturated due to pulmonary complications
• Work of breathing: Use of accessory muscles

Neurological Examination:

• Pupils: Mydriasis, responsive or fixed (severe toxicity)
• Cranial nerves: Focal deficits, nystagmus
• Motor function: Hyperreflexia, clonus, seizures, focal weakness
• Sensory: Paraesthesia, sensory loss
• Cerebellar: Ataxia, intention tremor
• Level of consciousness: Agitation, confusion, delirium, coma (GCS)

Gastrointestinal Examination:

• Abdominal tenderness: Mesenteric ischaemia, bowel infarction
• Bowel sounds: Hyperactive, absent (bowel infarction)
• Rectal examination: Occult blood (mesenteric ischaemia)

Skin and Soft Tissue:

• Skin: Diaphoresis, pallor, flushing, track marks (IV use), burns (smoking)
• Muscle: Tenderness (rhabdomyolysis), rigidity
• Temperature: Hyperthermia above 38°C, severe above 40°C

Cardiovascular Manifestations

Cocaine-Associated Chest Pain:

• Present in 40-57% of cocaine-related ED presentations [PMID: 10480473]
• Typical angina symptoms: Substernal chest pain, pressure, tightness
• Radiation: Left arm, jaw, neck, back
• Associated symptoms: Dyspnoea, diaphoresis, nausea, vomiting
• Onset: Typically within 60 minutes of use, but can occur up to 24 hours later [PMID: 10480473]

Arrhythmias:

• Sinus tachycardia: Most common (60-80%) [PMID: 28743204]
• Supraventricular tachycardia, atrial fibrillation
• Ventricular tachycardia, ventricular fibrillation (life-threatening)
• Bundle branch blocks: Right bundle branch block, left bundle branch block
• Prolonged QRS interval: Sodium channel blockade effect (QRS above 120 ms) [PMID: 28743204]
• QT prolongation: Increased risk of torsades de pointes

Hypertensive Crisis:

• SBP above 180-200 mmHg, DBP above 110-120 mmHg [PMID: 30185112]
• Risk of: Intracerebral haemorrhage, aortic dissection, myocardial infarction
• Symptoms: Headache, chest pain, dyspnoea, epistaxis, visual changes

Hypotension:

• Late or severe toxicity: Vasodilation, cardiac depression, myocardial dysfunction
• Shock: Cold clammy peripheries, oliguria, altered mental status
• Poor prognostic sign: Indicates cardiovascular collapse

Myocardial Ischaemia/Infarction:

• 0.7-6% of patients with cocaine-associated chest pain develop MI [PMID: 10480473]
• Younger population: Mean age 32-40 years (vs 50-60 for typical MI) [PMID: 9607769]
• Can occur in patients with normal coronary arteries (vasospasm)
• Typical ECG changes: ST elevation, ST depression, T-wave inversion, QT prolongation
• Troponin elevation: Serial measurement required

Aortic Dissection:

• Tearing chest/back pain radiating to interscapular region
• Pulse deficit, blood pressure discrepancy between arms
• New diastolic murmur (aortic regurgitation)
• High mortality without treatment: 1-2% per hour untreated [PMID: 17598800]

Cardiac Arrest:

• Ventricular fibrillation, asystole, pulseless electrical activity
• Associated with: Massive overdose, polydrug use, pre-existing cardiac disease

Neurological Manifestations

Seizures:

• Occur in 2-10% of acute cocaine toxicity presentations [PMID: 22608914]
• Generalised tonic-clonic seizures most common
• Single or multiple seizures; risk of status epilepticus
• Post-ictal state: Confusion, drowsiness

Ischaemic Stroke:

• Vasospasm of cerebral arteries
• Prothrombotic state: Increased platelet aggregation
• Embolic: From atrial fibrillation or left ventricular thrombus
• Symptoms: Focal neurological deficits, speech disturbance, visual changes

Intracerebral Haemorrhage:

• Severe hypertension causing vessel rupture
• Symptoms: Severe headache, focal deficits, decreased consciousness
• High mortality: 40-60%

Subarachnoid Haemorrhage:

• Ruptured berry aneurysm (hypertension)
• Symptoms: Thunderclap headache, neck stiffness, photophobia, vomiting

Excited Delirium Syndrome:

• Core Features: Severe agitation, delirium, hyperthermia, tachypnoea, diaphoresis [PMID: 19391715]
• Behaviour: Violence, paranoia, hallucinations, superhuman strength
• Physical: Mydriasis, hyperreflexia, muscle rigidity, rhabdomyolysis
• Temperature: Above 40°C in severe cases
• Laboratory: Metabolic acidosis, leukocytosis, elevated CK, myoglobinuria
• Mortality: 8-15% without appropriate management; higher with hyperthermia above 41°C [PMID: 19391715]

Headache:

• Tension-type headache: Most common
• Migraine: Exacerbated by cocaine use
• Subarachnoid haemorrhage: Thunderclap headache
• Hypertensive crisis: Severe headache, nausea, vomiting

Altered Mental Status:

• Agitation, confusion, delirium
• Psychosis: Paranoia, hallucinations, violent behaviour
• Coma: Severe toxicity, respiratory depression, post-ictal

Respiratory Manifestations

Pulmonary Oedema:

• Cardiogenic: Left ventricular failure from myocardial ischaemia
• Non-cardiogenic: Cocaine-induced pulmonary capillary leak
• Symptoms: Dyspnoea, frothy sputum, hypoxia
• Chest X-ray: Bilateral infiltrates, alveolar oedema

Bronchospasm:

• Cocaine is local anaesthetic but can cause bronchospasm
• Wheeze, dyspnoea, chest tightness
• History of asthma exacerbates effect

Pneumothorax:

• Barotrauma from excessive smoking (crack cocaine)
• Sudden pleuritic chest pain, dyspnoea, decreased breath sounds

Pulmonary Haemorrhage:

• Diffuse alveolar haemorrhage
• Haemoptysis, dyspnoea, hypoxia, anaemia

Aspiration:

• Seizures, decreased level of consciousness
• Chemical pneumonitis from gastric contents

Respiratory Depression:

• Late toxicity, polydrug use (opiates, benzodiazepines)
• Hypoventilation, respiratory acidosis, respiratory arrest

Gastrointestinal Manifestations

Mesenteric Ischaemia:

• Severe abdominal pain out of proportion to examination
• Vasoconstriction of mesenteric arteries
• Risk of bowel infarction, perforation, peritonitis [PMID: 17598800]

Bowel Infarction:

• Severe abdominal pain, bloody diarrhoea, sepsis
• High mortality: 50-70%

Ischaemic Colitis:

• Abdominal pain, bloody diarrhoea
• Segmental colonic wall thickening

Acute Pancreatitis:

• Vasoconstriction of pancreatic vessels
• Epigastric pain radiating to back, nausea, vomiting

Liver Injury:

• Transaminase elevation, hepatitis
• Hepatic necrosis in severe toxicity

Gastrointestinal Haemorrhage:

• Stress ulceration, Mallory-Weiss tear (vomiting)
• Upper or lower gastrointestinal bleeding

Psychiatric Manifestations

Agitation and Anxiety:

• Restlessness, pacing, hyperactivity
• Severe agitation: Violent behaviour, risk to self and others

Psychosis:

• Paranoia, persecutory delusions
• Visual, auditory, tactile hallucinations
• Formication: Sensation of insects crawling under skin ("cocaine bugs")

Violence:

• Associated with psychosis and paranoia
• Risk to patients, staff, others
• Requires immediate restraint and sedation

Suicidality:

• Cocaine crash: Depression, hopelessness
• Suicidal ideation, self-harm

Depression and Anhedonia:

• Withdrawal syndrome: Dysphoria, fatigue, increased appetite
• Craving, risk of relapse

Cutaneous Manifestations

Diaphoresis:

• Profuse sweating
• Due to sympathetic overdrive

Pallor and Flushing:

• Cutaneous vasoconstriction causing pallor
• Flushing with hyperthermia

Track Marks:

• Intravenous drug use signs
• Needles marks, scars, venous sclerosis

Burns:

• Thermal burns from smoking crack cocaine (pipes, lighters)
• Chemical burns from cocaine impurities

Necrotising Fasciitis:

• Injection drug use: Skin popping, contaminated equipment
• Soft tissue infection, necrosis

Cocaine Body Stacking (Cocaethylene Syndrome)

Pathophysiology:

• Cocaine + alcohol metabolised by liver to form cocaethylene [PMID: 2846216]
• Cocaethylene half-life: 3-5 hours (longer than cocaine alone)
• More potent cardiotoxic effects than cocaine or alcohol alone
• Increased euphoria, reinforcing combined use

Clinical Features:

• Prolonged toxicity: Symptoms last 12-24 hours vs 4-6 hours for cocaine alone
• Severe cardiovascular effects: Tachycardia, hypertension, arrhythmias
• Increased risk of myocardial ischaemia, arrhythmias, sudden death [PMID: 2846216]
• Enhanced psychomotor agitation, psychosis

Management:

• Prolonged observation: 12-24 hours required
• Supportive care: Benzodiazepines, fluids, cardiac monitoring
• Treatment of complications: Myocardial ischaemia, arrhythmias

Excited Delirium Syndrome

Definition: Life-threatening syndrome of extreme agitation, delirium, hyperthermia, autonomic instability, and rhabdomyolysis following cocaine or other stimulant use [PMID: 19391715].

Diagnostic Criteria (at least 6 of 8):

1. Severe agitation, paranoia, or violence
2. Delirium or psychosis (hallucinations, paranoia)
3. Hyperthermia (temperature above 38°C; severe above 40°C)
4. Diaphoresis
5. Tachypnoea (RR above 20)
6. Mydriasis
7. Superhuman strength (pain insensitivity, muscle rigidity)
8. Rhabdomyolysis (CK above 1000 U/L)

Pathophysiology:

• Massive catecholamine surge: Noradrenaline, dopamine, serotonin
• Dopaminergic dysregulation in limbic system: Psychosis, agitation
• Impaired thermoregulation: Heat production exceeds dissipation
• Rhabdomyolysis: Direct myotoxicity, prolonged muscle hyperactivity
• Metabolic acidosis: Lactic acidosis from muscle breakdown, seizures
• Autonomic instability: Labile blood pressure, heart rate

Clinical Presentation:

• Behaviour: Violent, combative, paranoid, hallucinating
• Physical: Mydriasis, hyperreflexia, muscle rigidity, diaphoresis
• Temperature: Above 38°C; severe above 40°C
• Neurological: Agitated delirium, psychosis, seizures
• Cardiovascular: Tachycardia (HR above 120), hypertension (SBP above 180), arrhythmias
• Renal: Myoglobinuria (dark urine), oliguria, acute kidney injury

Differential Diagnosis:

• Serotonin syndrome (similar features)
• Neuroleptic malignant syndrome (exposure to antipsychotics)
• Malignant hyperthermia (anaesthetic agents)
• Heat stroke
• Thyroid storm
• Hypoglycaemia

Management:

Contraindications:

• Beta-blockers: Contraindicated (risk of unopposed alpha vasoconstriction)
• Antipsychotics: Avoid in acute phase (lower seizure threshold, anticholinergic effects impair cooling)
• Physostigmine: Contraindicated (can cause seizures, asystole)

Prognosis:

• Mortality: 8-15% without appropriate management; higher with hyperthermia above 41°C [PMID: 19391715]
• Good outcome if: Early recognition, aggressive benzodiazepines, active cooling, airway protection
• Poor prognosis if: Delayed presentation, hyperthermia above 41°C, refractory seizures, multi-organ failure

Complications

Cardiovascular Complications

Cocaine-Associated Myocardial Ischaemia/Infarction:

• Pathophysiology: Coronary vasoconstriction, increased oxygen demand, thrombogenesis, accelerated atherosclerosis [PMID: 9607769]
• Clinical: Chest pain (40-57% of presentations), dyspnoea, diaphoresis, nausea
• ECG: ST elevation/depression, T-wave inversion, QT prolongation
• Management:
  1. Oxygen: SpO2 94-98% if hypoxic
  2. Nitroglycerin: Sublingual 400 mcg, repeat q5min (relieves vasospasm) [PMID: 10480473]
  3. Benzodiazepines: Lorazepam 2-4 mg IV (reduces catecholamine surge)
  4. Aspirin: 300 mg chewed (antiplatelet) [PMID: 9607769]
  5. Morphine: 2.5-5 mg IV if ongoing pain (cautious: respiratory depression)
  6. Consider: Phentolamine (if nitroglycerin contraindicated)
  7. CONTRAINDICATED: Beta-blockers (risk of unopposed alpha vasoconstriction)
  8. CONTRAINDICATED: Procainamide, disopyramide (sodium channel blockade)
• PCI: Consider for STEMI or NSTEMI with ongoing ischaemia [PMID: 10480473]

Arrhythmias:

• SVT, AF: Rate control (benzodiazepines, calcium channel blockers)
• VT/VF: ACLS algorithm, avoid amiodarone (prolongs QT), consider lidocaine
• Bradycardia: Late toxicity, cardiac depression, may require pacing
• QRS widening: Sodium bicarbonate 1-2 mEq/kg IV (if QRS above 120 ms)

Aortic Dissection:

• Pathophysiology: Severe hypertension causing shear stress [PMID: 17598800]
• Clinical: Tearing chest/back pain, pulse deficit, BP discrepancy, diastolic murmur
• Diagnosis: CT angiography, transoesophageal echocardiography
• Management: Anti-impulse therapy (beta-blockers contraindicated in cocaine users), urgent surgical consultation
• Contraindication: Beta-blockers (initially) due to risk of unopposed alpha vasoconstriction

Cardiac Failure:

• Pathophysiology: Myocardial ischaemia, catecholamine toxicity, cardiomyopathy
• Clinical: Dyspnoea, orthopnoea, peripheral oedema, pulmonary oedema
• Management: Oxygen, nitrates, diuretics (furosemide), non-invasive ventilation

Neurological Complications

Seizures and Status Epilepticus:

• Pathophysiology: Lowered seizure threshold, focal cerebral ischaemia [PMID: 22608914]
• Management:
  1. Benzodiazepines: Lorazepam 4 mg IV (or diazepam 10 mg IV), repeat if seizures persist
  2. Second-line: Phenytoin 15-20 mg/kg IV (loading), levetiracetam 1000-2000 mg IV
  3. Third-line: Propofol infusion (if refractory status)
  4. Airway protection: Intubate if compromised airway or prolonged seizures
  5. Temperature control: Treat hyperthermia

Ischaemic Stroke:

• Pathophysiology: Cerebral vasospasm, prothrombotic state
• Clinical: Focal neurological deficits, speech disturbance, hemiparesis
• Management: Supportive, thrombolysis contraindicated (uncontrolled hypertension)
• Prevention: Avoid vasoconstrictors, manage blood pressure

Intracerebral Haemorrhage:

• Pathophysiology: Severe hypertension, vessel rupture
• Clinical: Severe headache, focal deficits, decreased consciousness
• Management: Airway protection, control hypertension (labetalol or nitroprusside), neurosurgical consultation

Subarachnoid Haemorrhage:

• Pathophysiology: Ruptured aneurysm (hypertension)
• Clinical: Thunderclap headache, neck stiffness, vomiting, photophobia
• Management: CT head, neurosurgical consultation, control hypertension

Excited Delirium: Detailed above.

Respiratory Complications

Pulmonary Oedema:

• Pathophysiology: Cardiogenic (LV failure) or non-cardiogenic (capillary leak)
• Clinical: Dyspnoea, frothy sputum, hypoxia, crackles on auscultation
• Management:
  1. Oxygen: Non-rebreather mask or CPAP 10-15 cmH2O
  2. Nitrates: Nitroglycerin infusion (reduce preload)
  3. Diuretics: Furosemide 40-80 mg IV
  4. Consider: Intubation and ventilation (refractory hypoxia)

Bronchospasm:

• Management: Salbutamol 5 mg nebulised, ipratropium 500 mcg nebulised, consider magnesium 2 g IV

Pneumothorax:

• Management: Needle decompression (tension), chest tube (simple)

Aspiration Pneumonitis:

• Management: Antibiotics if infection suspected, supportive care

Renal Complications

Rhabdomyolysis-Induced Acute Kidney Injury:

• Pathophysiology: Myoglobinuria, hypovolaemia, direct tubular toxicity [PMID: 22608914]
• Clinical: Dark urine, oliguria, elevated CK (above 1000 U/L)
• Management:
  1. Aggressive IV fluids: Normal saline 1-2 L bolus, then 200-500 mL/hr to achieve urine output 100-200 mL/hr
  2. Alkalinisation: Consider sodium bicarbonate if pH below 7.2 (controversial)
  3. Monitor: CK, renal function, electrolytes (hyperkalaemia)
  4. Renal replacement therapy: If refractory acidosis, hyperkalaemia, fluid overload

Metabolic Complications

Hyperthermia:

• Pathophysiology: Impaired thermoregulation, increased heat production
• Clinical: Temperature above 38°C; severe above 40°C; diaphoresis
• Management: Active cooling (evaporative, ice packs, cooling blankets), consider cold IV fluids (temperature above 40°C)

Metabolic Acidosis:

• Pathophysiology: Lactic acidosis (seizures, muscle activity), renal failure
• Management: Correct underlying cause, consider sodium bicarbonate if pH below 7.1

Electrolyte Disturbances:

• Hyperkalaemia: Rhabdomyolysis, renal failure; treat with calcium gluconate, insulin/dextrose, salbutamol
• Hypokalaemia: Diuresis, vomiting; treat with potassium replacement
• Hypocalcaemia: Metabolic alkalosis, citrate transfusion; treat with calcium gluconate

Traumatic Complications

Trauma:

• Falls, assaults, motor vehicle accidents during intoxication
• Blunt and penetrating injuries
• Manage according to ATLS principles

Burns:

• Thermal burns from smoking crack cocaine
• Electrical burns from homemade equipment
• Assess burn depth, surface area, fluid resuscitation

Infectious Complications

Endocarditis:

• IV drug use, contaminated equipment
• Staphylococcus aureus most common
• Blood cultures, echocardiography, prolonged antibiotics

Skin and Soft Tissue Infections:

• Abscesses, cellulitis, necrotising fasciitis
• Incision and drainage, antibiotics

Hepatitis B and C:

• Parenteral transmission
• Vaccinate (HBV), test (HCV)

HIV:

• Parenteral transmission
• Test and refer to infectious diseases

Investigations

Initial Assessment

Vital Signs:

• Blood pressure: Both arms (assess aortic dissection)
• Heart rate: Tachycardia, arrhythmias
• Respiratory rate: Tachypnoea
• Oxygen saturations: Hypoxia
• Temperature: Hyperthermia (core: rectal, bladder, oesophageal)
• Level of consciousness: Glasgow Coma Scale

Cardiac Monitoring:

• Continuous ECG monitoring: Detect arrhythmias, ischaemia
• 12-lead ECG: Baseline and serial (every 4-6 hours if chest pain)

Pulse Oximetry:

• Continuous monitoring
• Maintain SpO2 94-98% if hypoxic

Cardiac Investigations

12-Lead ECG:

• Indication: All patients with cocaine use, especially chest pain, arrhythmias, haemodynamic instability [PMID: 10480473]
• Findings:
  • "Sinus tachycardia: Most common"
  • "ST elevation/depression: Ischaemia/infarction"
  • "T-wave inversion: Ischaemia"
  • "QT prolongation: Increased arrhythmia risk"
  • "QRS widening: Sodium channel blockade (above 120 ms)"
  • "Bundle branch blocks: RBBB, LBBB"
• Serial ECGs: Every 4-6 hours if chest pain or abnormal baseline

Cardiac Biomarkers:

• High-sensitivity Troponin: At presentation and 3-6 hours later [PMID: 10480473]
• Interpretation: Elevated troponin indicates myocardial injury, rule in MI with ECG changes
• Serial measurement: If initial negative and clinical suspicion high

Chest X-ray:

• Indication: Chest pain, dyspnoea, suspected pulmonary oedema, pneumothorax
• Findings: Pulmonary oedema, widened mediastinum (aortic dissection), pneumothorax

CT Angiography:

• Indication: Suspected aortic dissection (tearing chest/back pain, pulse deficit, BP discrepancy)
• Findings: Intimal flap, false lumen, dissection extent
• Contraindication: Severe renal impairment (contrast nephropathy risk)

Echocardiography:

• Indication: Suspected cardiac failure, valve dysfunction (aortic regurgitation in dissection)
• Findings: Wall motion abnormalities, ejection fraction, valvular pathology

Neurological Investigations

CT Head (Non-contrast):

• Indication: Seizures, altered mental status, focal neurological deficits, severe headache, trauma [PMID: 17598800]
• Findings: Intracerebral haemorrhage, subarachnoid haemorrhage, ischaemic stroke (early)

MRI Brain:

• Indication: Suspected ischaemic stroke if CT negative, diagnostic uncertainty
• Findings: Acute ischaemia, structural abnormalities

Lumbar Puncture:

• Indication: Suspected subarachnoid haemorrhage with negative CT
• Findings: Xanthochromia, elevated RBC count

EEG:

• Indication: Seizures without obvious cause, altered mental status, suspected non-convulsive status

Respiratory Investigations

Arterial Blood Gas (ABG):

• Indication: Hypoxia, respiratory distress, altered mental status
• Findings: Hypoxaemia, hypercapnia, respiratory acidosis, metabolic acidosis

Chest X-ray:

• See cardiac investigations above

CT Pulmonary Angiography:

• Indication: Suspected pulmonary embolism (dyspnoea, pleuritic pain, hypoxia)

Toxicological Investigations

Urine Drug Screen:

• Indication: Diagnostic confirmation, polydrug use assessment
• Findings: Cocaine metabolites (benzoylecgonine) detected 2-4 days after use
• Limitations: Qualitative (not quantitative), does not correlate with severity

Serum Cocaine Level:

• Indication: Clinical toxicology, research (routinely not required)
• Limitations: Correlation with toxicity poor, not widely available

Serum Ethanol Level:

• Indication: Suspected cocaethylene syndrome (cocaine + alcohol)

Other Toxicology:

• Indication: Suspected polydrug use (opiates, benzodiazepines, amphetamines)

Laboratory Investigations

Complete Blood Count (CBC):

• Indication: All patients with acute toxicity
• Findings: Leukocytosis (stress, infection), anaemia (trauma, chronic disease)

Renal Function:

• Indication: All patients, especially rhabdomyolysis
• Findings: Elevated urea, creatinine, acute kidney injury

Electrolytes:

• Indication: All patients
• Findings: Hyperkalaemia (rhabdomyolysis), hypokalaemia (diuresis), hypocalcaemia

Liver Function Tests:

• Indication: Hepatic injury, alcohol use, infectious hepatitis
• Findings: Elevated transaminases, bilirubin

Coagulation Studies:

• Indication: Severe trauma, suspected DIC, before invasive procedures
• Findings: Prolonged PT/APTT, low fibrinogen, elevated D-dimer

Creatine Kinase (CK):

• Indication: Suspected rhabdomyolysis, seizures, prolonged agitation
• Findings: Elevated CK (above 1000 U/L indicates significant rhabdomyolysis) [PMID: 22608914]

Urinalysis:

• Indication: Rhabdomyolysis, urinary tract infection
• Findings: Myoglobinuria (dark urine, positive blood on dipstick without RBCs on microscopy), casts

Serum Glucose:

• Indication: Altered mental status, seizures, diabetic patients
• Findings: Hypoglycaemia (alcohol co-ingestion, decreased oral intake)

Inflammatory Markers:

• CRP, ESR: Non-specific inflammation, infection

Blood Cultures:

• Indication: Suspected sepsis, endocarditis, febrile patients

Management

Immediate Resuscitation (ABCDE)

A - Airway:

• Assess airway patency, protect cervical spine if trauma suspected
• Position: Head tilt/chin lift (unless trauma), jaw thrust
• Consider: Oropharyngeal airway (OPA), nasopharyngeal airway (NPA) if GCS below 9
• Indications for intubation: Coma (GCS below 8), seizures, respiratory failure, uncontrolled agitation (excited delirium)

B - Breathing:

• Oxygen: Maintain SpO2 94-98% (if hypoxic)
• Ventilatory support: Bag-valve-mask if inadequate breathing
• Intubation and ventilation: Apnoea, severe hypoxia, respiratory fatigue, hypercapnia (PaCO2 above 50-60 mmHg)

C - Circulation:

• IV access: Two large-bore cannulae (14-16G)
• Fluid resuscitation: Normal saline 250-500 mL bolus, titrate to haemodynamics
• Cardiac monitoring: Continuous ECG, blood pressure
• Treat arrhythmias: According to ACLS algorithm (avoid amiodarone in cocaine toxicity)
• Treat hypertension: Benzodiazepines first-line, phentolamine second-line (if unresponsive)
• Treat hypotension: Fluid bolus, consider vasopressors (noradrenaline preferred)

D - Disability (Neurological):

• Level of consciousness: Glasgow Coma Scale
• Pupils: Size, reactivity, symmetry
• Blood glucose: Capillary glucose if altered mental status (treat hypoglycaemia)
• Treat seizures: Benzodiazepines (lorazepam 4 mg IV or diazepam 10 mg IV)

E - Exposure:

• Full examination: Identify hidden injuries or trauma
• Temperature: Core temperature (rectal, bladder, oesophageal); treat hyperthermia above 38.5°C
• Remove wet clothing, apply warming blankets if hypothermic

Specific Antidotes and Treatments

Benzodiazepines (First-line Universal Antidote):

• Mechanism: GABA-A receptor agonist, reduces central sympathetic outflow [PMID: 22608914]
• Effects: Decreases agitation, heart rate, blood pressure, seizure risk
• Dosing: Titrate to effect (sedation, HR below 100-110, SBP below 160-170)
• Contraindications: None absolute (relative: severe respiratory depression - may require intubation)
• Caution: Respiratory depression (monitor airway, prepare for intubation)

Nitroglycerin (for Cocaine-Associated Chest Pain):

• Dose: Sublingual 400 mcg, repeat q5min PRN (max 3 doses)
• Indication: Ongoing chest pain, myocardial ischaemia [PMID: 10480473]
• Mechanism: Venous and arterial vasodilation, relieves coronary vasospasm
• Contraindications: SBP below 90, RV infarction, phosphodiesterase inhibitors (sildenafil)
• Alternative: Nitroglycerin infusion 5-10 mcg/min, titrate to effect

Phentolamine (for Severe Hypertension):

• Dose: 1-5 mg IV bolus, titrate to effect (can repeat)
• Indication: Severe hypertension unresponsive to benzodiazepines (SBP above 180-200 mmHg) [PMID: 10480473]
• Mechanism: Alpha-adrenergic antagonist, reverses alpha-mediated vasoconstriction
• Contraindications: Severe hypotension, myocardial infarction, phaeochromocytoma
• Alternative: Nitroprusside infusion 0.25-5 mcg/kg/min (titrate to BP)

Aspirin (for Myocardial Ischaemia):

• Dose: 300 mg chewed (loading), then 100 mg daily
• Indication: Suspected myocardial ischaemia/infarction [PMID: 9607769]
• Contraindications: True aspirin allergy, active bleeding

Sodium Bicarbonate (for QRS Widening):

• Dose: 1-2 mEq/kg IV bolus (50-100 mL of 8.4% NaHCO3)
• Indication: QRS interval above 120 ms, ventricular arrhythmias [PMID: 28743204]
• Mechanism: Alkalinisation reduces sodium channel blockade
• Repeat: QRS above 120 ms persists after initial bolus
• Contraindication: Severe metabolic alkalosis

Lidocaine (for Ventricular Arrhythmias):

• Dose: 1-1.5 mg/kg IV bolus, then 1-4 mg/min infusion
• Indication: Ventricular tachycardia, ventricular fibrillation (resistant to first-line ACLS)
• Mechanism: Sodium channel blockade (class Ib antiarrhythmic)
• Contraindications: Severe bradycardia, second/third degree heart block (without pacemaker)

Physostigmine (CONTRAINDICATED):

• Reason: Can cause seizures, asystole, cardiac arrest in cocaine toxicity
• Avoid: Contraindicated in all cases of cocaine toxicity

Beta-Blockers (CONTRAINDICATED):

• Reason: Unopposed alpha-mediated vasoconstriction can worsen hypertension, coronary vasospasm, myocardial ischaemia [PMID: 28743204]
• Avoid: All beta-blockers (including labetalol which has alpha-blocking activity)
• Alternative: Benzodiazepines, phentolamine, calcium channel blockers

Management of Specific Presentations

Cocaine-Associated Chest Pain:

• Observation Protocol: Serial ECGs and troponin at 0, 3, 6, 9, 12 hours; discharge if pain-free, negative troponin, normal ECG [PMID: 10480473]

Severe Hypertension:

• Contraindications: Beta-blockers (avoid) [PMID: 28743204]

Seizures:

• Refractory Status: Propofol infusion, midazolam infusion, consider ICU admission

Hyperthermia:

• Cooling Methods:
  • "Evaporative cooling: Water spray, fanning (most effective)"
  • "Ice packs: Axillae, groin, neck"
  • "Cooling blankets: Continuous temperature regulation"
  • "Cold IV fluids: 0.9% saline 500-1000 mL (temperature above 40°C)"

Excited Delirium Syndrome: Detailed above.

Rhabdomyolysis:

• Target Urine Output: 100-200 mL/hr (adult)

Cocaine-Induced Aortic Dissection:

• Anti-Impulse Therapy: Goal SBP 100-120 mmHg, HR below 70 bpm

Polydrug Toxicity Management

Cocaine + Opiates:

• Clinical: Decreased respiratory drive, mixed stimulant-depressant presentation
• Management:
  • Airway support first (may need intubation)
  • "Naloxone: 0.04-0.4 mg IV titrated (reverses respiratory depression)"
  • "Benzodiazepines: Treat agitation, seizures"
  • Avoid high-dose naloxone (can precipitate acute withdrawal, hypertension)

Cocaine + Alcohol:

• Clinical: Cocaethylene syndrome (prolonged toxicity, increased cardiotoxicity)
• Management: Prolonged observation (12-24 hours), supportive care, treat complications

Cocaine + Benzodiazepines:

• Clinical: Blunted stimulant effects, increased sedation
• Management: Supportive care, monitor for respiratory depression, treat underlying cocaine toxicity

Cocaine + Amphetamines:

• Clinical: Severe sympathomimetic toxicity (additive effects)
• Management: High-dose benzodiazepines, aggressive cooling, treat complications

Cocaine + Antidepressants:

• Clinical: Serotonin syndrome (if SSRIs/SNRIs)
• Management: Discontinue serotonergic drugs, benzodiazepines, cyproheptadine (5-HT2A antagonist), cooling

Disposition

Admission Criteria:

• Severe cardiovascular complications (MI, arrhythmias, aortic dissection)
• Severe neurological complications (stroke, seizures, excited delirium)
• Severe respiratory complications (pulmonary oedema, respiratory failure)
• Rhabdomyolysis (CK above 5000 U/L, renal impairment)
• Hyperthermia above 40°C
• Persistent haemodynamic instability
• Coma (GCS below 8)
• Pregnancy (fetal monitoring, placental abruption)
• Inability to care for self, lack of social support

Observation Criteria:

• Cocaine-associated chest pain with negative workup: Observation for 9-12 hours [PMID: 10480473]
• Mild to moderate toxicity resolving with treatment
• Serial troponin, ECG monitoring
• Discharge if: Asymptomatic, normal vital signs, negative serial troponin, normal ECG

Discharge Criteria:

• Asymptomatic (no chest pain, dyspnoea, neurological symptoms)
• Normal vital signs (SBP below 140, HR below 100, temperature below 37.5°C)
• Normal serial troponin (at least two measurements 4-6 hours apart)
• Normal ECG
• Able to care for self, social support
• Referral to addiction services
• Safety-netting: Return precautions

Specialist Consultation:

• Cardiology: MI, arrhythmias, aortic dissection
• Neurology: Stroke, seizures, altered mental status
• Cardiothoracic surgery: Aortic dissection
• Intensive care: Severe toxicity, multi-organ failure
• Psychiatry: Addiction referral, psychiatric evaluation
• Social work: Discharge planning, support services

Special Populations

Pregnancy

Pathophysiology:

• Cocaine crosses placenta (fetal exposure equals maternal levels) [PMID: 12736467]
• Vasoconstriction: Placental insufficiency, fetal hypoxia
• Preterm labour risk: 4-5 times increased risk
• Placental abruption: 2-3 times increased risk [PMID: 12736467]

Maternal Risks:

• Myocardial ischaemia, arrhythmias
• Hypertensive crisis, stroke
• Placental abruption, severe haemorrhage
• Preterm labour, precipitous delivery
• Seizures, excited delirium

Fetal Risks:

• Intrauterine growth restriction (IUGR)
• Preterm birth (37-40%)
• Placental abruption (10-15%)
• Fetal distress, stillbirth
• Neonatal abstinence syndrome (NAS)
• Long-term neurodevelopmental delay

Management:

• Fetal monitoring: Continuous cardiotocography (CTG) if viable gestation
• Treat maternal toxicity: Benzodiazepines (category B), supportive care
• Avoid: Beta-blockers, ACE inhibitors, teratogenic medications
• Obstetrics consultation: Placental abruption, preterm labour, fetal distress
• Delivery: Immediate delivery if placental abruption, non-reassuring fetal status, severe maternal instability

Neonatal Management:

• Monitor for neonatal abstinence syndrome (NAS)
• Supportive care: Feeding, swaddling, non-pharmacological measures
• Pharmacological: Morphine, phenobarbital (if severe NAS)

Paediatric Patients

Paediatric Toxicity Sources:

• Accidental ingestion (household exposure)
• Passive exposure (maternal use during pregnancy, breast milk)
• Drug trafficking ("body packing"
• ingested packets)
• Adolescent recreational use

Management:

• Weight-based dosing for all medications
• Aggressive fluid resuscitation (higher risk of dehydration)
• Monitor glucose more frequently (hypoglycaemia risk)
• Consider child protection if accidental exposure
• Social work involvement

Body Packers:

• Risk: Packet rupture causing massive overdose, bowel obstruction
• Management:
  • "Asymptomatic: Whole bowel irrigation with polyethylene glycol (PEG) 1-2 L/hr until packets passed"
  • "Symptomatic: Urgent surgical consultation (packet rupture suspected)"
  • "Imaging: Abdominal X-ray (look for radiopaque packets), CT scan"
  • "Observation: 24-48 hours, monitor for toxicity"

Elderly Patients

Risk Factors:

• Pre-existing cardiovascular disease (CAD, hypertension)
• Decreased physiological reserve
• Polypharmacy (drug interactions)
• Altered pharmacokinetics (reduced renal/hepatic clearance)

Management:

• Lower doses of benzodiazepines (reduce risk of oversedation)
• Aggressive cardiovascular monitoring
• Assess for drug interactions
• Consider admission even for mild toxicity
• Social work: Discharge planning, support services

Patients with Pre-existing Medical Conditions

Ischaemic Heart Disease:

• Increased risk of myocardial infarction
• Management: Benzodiazepines, nitrates, avoid beta-blockers
• Cardiology consultation early

Hypertension:

• Exacerbated hypertension, risk of stroke, aortic dissection
• Management: Benzodiazepines, phentolamine (if severe)
• Avoid: Beta-blockers (initially)

Seizure Disorder:

• Lower seizure threshold, risk of status epilepticus
• Management: Aggressive benzodiazepine use, consider phenytoin loading
• Continue antiepileptic medications

Psychiatric Illness:

• Exacerbation of psychosis, mania, depression
• Management: Benzodiazepines, avoid antipsychotics in acute phase
• Psychiatry consultation

Renal Impairment:

• Reduced clearance of metabolites, increased toxicity duration
• Management: Adjust fluid resuscitation, monitor for fluid overload
• Dose adjustment for renally cleared medications

Indigenous Health Considerations

Aboriginal and Torres Strait Islander Peoples

Epidemiology:

• Cocaine use: Lower prevalence than metropolitan areas but increasing in urban communities
• Polydrug use: High rates of concurrent alcohol, cannabis, amphetamine use
• Health disparities: Higher rates of cardiovascular disease, renal disease, diabetes

Cultural Safety:

• Communication: Use respectful, clear language, avoid jargon
• Family involvement: Include family members in discussions (if patient consents)
• Respect cultural protocols: Welcome to Country, smoking ceremonies (if appropriate)
• Acknowledge intergenerational trauma: Approach with empathy and understanding

Management Considerations:

• Cultural liaison: Aboriginal Health Worker or Aboriginal Liaison Officer where available
• Family decision-making: Family elders may play key role in decision-making
• Spirituality: Acknowledge spiritual beliefs and practices
• Gender considerations: Same-gender clinicians for sensitive discussions where possible

Access Barriers:

• Geographic: Remote communities, limited access to specialist care
• Cultural: Mistrust of mainstream healthcare, fear of judgment
• Socioeconomic: Financial constraints, transport limitations
• Stigma: Concerns about confidentiality within small communities

Collaborative Care:

• Aboriginal Medical Services (AMS): Coordinate care with primary providers
• Aboriginal Community Controlled Health Services (ACCHS): Referral pathways
• Remote area nurses: Liaise with local health services
• Telehealth: Specialist consultation for remote communities

Social Determinants:

• Housing: Overcrowding, homelessness
• Education: Health literacy, education level
• Employment: Unemployment, economic disadvantage
• Social support: Family structure, community support networks

Māori (New Zealand) Considerations

Epidemiology:

• Cocaine use: Lower than Australian prevalence but rising
• Methamphetamine use higher priority in New Zealand
• Similar patterns of polydrug use and alcohol co-ingestion

Cultural Concepts:

• Whānau (family): Family involvement in care decisions
• Tikanga (customs): Respect cultural protocols (karakia, wairua)
• Manaakitanga (care): Provide care with respect and compassion
• Whakapapa (genealogy): Understand family and cultural connections

Management:

• Cultural support: Māori cultural support workers
• Kaupapa Māori services: Where available
• Family meetings: Include whānau in discussions
• Respect tapu/noa concepts: Ensure cultural appropriateness of care

Health Disparities:

• Higher cardiovascular disease rates
• Lower access to specialist services
• Higher rates of comorbid conditions (diabetes, renal disease)

Remote and Rural Considerations

Challenges in Remote Practice

Limited Resources:

• Limited imaging: May not have CT angiography, echocardiography
• Limited laboratory: May not have troponin, toxicology screening
• Limited monitoring: May not have continuous cardiac monitoring
• Limited specialist access: May need to transfer for specialist care

Retrieval Medicine:

• Royal Flying Doctor Service (RFDS): Air retrieval for critically ill patients
• Retrieval coordination: Early activation (consider ground, air, or boat retrieval)
• Transfer criteria: Unstable patient, need for specialist care, limited local resources
• Stabilisation before transfer: Aggressive resuscitation, secure airway, haemodynamic support

Telemedicine:

• Telehealth consultation: Specialist advice (cardiology, toxicology, ICU)
• Tele-ECG transmission: ECG interpretation by specialist
• Image transfer: CT scan interpretation by remote radiologist
• Video consultation: Multi-disciplinary team discussion

Extended Transport Times:

• Golden hour: Aggressive resuscitation during prolonged transport
• Medication availability: Ensure adequate medications for transfer (benzodiazepines, nitroglycerin)
• Equipment: Portable monitoring, airway equipment, emergency medications

Limited Staff:

• Small team: Nurse, doctor, possibly paramedic
• Skills mix: May not have critical care specialist
• Protocols: Use of standardised protocols for management
• Debriefing: Post-event debriefing for team members

Rural Emergency Department Protocols

Cocaine-Associated Chest Pain Protocol:

1. Immediate ECG, cardiac monitor
2. Oxygen if SpO2 below 94%
3. Nitroglycerin 400 mcg SL (if SBP above 90)
4. Aspirin 300 mg chewed
5. Benzodiazepines (lorazepam 2-4 mg IV)
6. Serial ECGs, monitor for arrhythmias
7. Transfer if: Troponin positive, ECG changes, ongoing pain, haemodynamic instability

Hypertensive Crisis Protocol:

1. Benzodiazepines first-line (diazepam 5-10 mg IV)
2. Phentolamine 1-5 mg IV (if SBP above 200 and unresponsive to BZD)
3. Nitroprusside infusion (if refractory, requires ICU monitoring)
4. Transfer if: Refractory hypertension, end-organ damage

Excited Delirium Protocol:

1. Immediate safety: Staff protection
2. Benzodiazepines: Aggressive dosing (lorazepam 4-8 mg IV, repeat)
3. Early intubation: If uncontrolled agitation, temperature above 40°C
4. Active cooling: Ice packs, cooling blankets, evaporative cooling
5. Aggressive fluids: 1-2 L NS bolus, then 250-500 mL/hr
6. Urgent transfer: To ICU or tertiary centre

Retrieval Coordination:

• Early activation: Call RFDS or retrieval service as soon as patient identified
• Provide clear handover: Situation, Background, Assessment, Recommendation (SBAR)
• Prepare for transport: Secure airway, IV access, medications, monitoring
• Communication: Maintain communication with retrieval team

Follow-Up Care:

• Local follow-up: General practitioner, Aboriginal Medical Service
• Specialist follow-up: Virtual or face-to-face appointment
• Addiction services: Referral to local drug and alcohol service
• Mental health: Mental health professional referral

Pitfalls and Pearls

⚠️ Warning: CRITICAL PITFALL: NEVER administer beta-blockers (including labetalol) to patients with cocaine toxicity. This can cause unopposed alpha-mediated vasoconstriction, worsening hypertension, coronary vasospasm, myocardial ischaemia, and precipitating cardiac arrest. Benzodiazepines are the safe first-line treatment for cocaine-associated hypertension and tachycardia. [PMID: 28743204]

⚠️ Warning: CRITICAL PITFALL: Excited delirium syndrome is a medical emergency with high mortality. Early recognition and aggressive treatment with high-dose benzodiazepines, active cooling, and rapid sequence intubation is essential. Delayed treatment significantly increases mortality. [PMID: 19391715]

⚠️ Warning: CRITICAL PITFALL: Cocaine-associated myocardial infarction can occur in patients with normal coronary arteries due to coronary vasospasm. Do not assume young patients cannot have MI based on age alone. Perform serial troponin and ECG monitoring for 9-12 hours. [PMID: 10480473]

⚠️ Warning: CRITICAL PITFALL: Cocaine + alcohol forms cocaethylene with prolonged toxicity and increased cardiotoxicity. Observation period should be extended to 12-24 hours when both substances are co-ingested. [PMID: 2846216]

⚠️ Warning: CRITICAL PITFALL: Patients with cocaine-associated chest pain and negative initial workup can develop delayed MI. Serial troponin and ECG at 0, 3, 6, 9, 12 hours is mandatory. [PMID: 10480473]

Clinical Pearl: PEARL: Benzodiazepines are the universal antidote for cocaine toxicity. They reduce agitation, heart rate, blood pressure, seizures, and catecholamine surge. Titrate to clinical effect (sedation, HR below 100-110, SBP below 160-170). [PMID: 22608914]

Clinical Pearl: PEARL: Nitroglycerin is effective for cocaine-associated chest pain due to coronary vasospasm. It relieves chest pain in 60-80% of patients with cocaine-associated angina. [PMID: 10480473]

Clinical Pearl: PEARL: Phentolamine is the alpha-blocker of choice for severe hypertension unresponsive to benzodiazepines. Use 1-5 mg IV bolus, titrated to blood pressure response. [PMID: 10480473]

Clinical Pearl: PEARL: Rhabdomyolysis management requires aggressive IV fluids targeting urine output 100-200 mL/hr. Early fluid resuscitation prevents acute kidney injury. [PMID: 22608914]

Clinical Pearl: PEARL: Cocaine-induced aortic dissection can occur in younger patients (30-50 years) without pre-existing aneurysms. Suspect in patients with severe tearing chest/back pain, especially with hypertension. [PMID: 17598800]

Clinical Pearl: PEARL: Cocaine toxicity can cause ischaemic stroke in patients without traditional risk factors. Consider stroke in young patients with focal neurological deficits and cocaine use. [PMID: 17598800]

Clinical Pearl: PEARL: Pregnant patients with cocaine toxicity have increased risk of placental abruption and preterm labour. Continuous fetal monitoring and obstetrics consultation is essential. [PMID: 12736467]

Clinical Pearl: PEARL: Body packers (drug mules) require whole bowel irrigation with polyethylene glycol until packets pass. Surgical consultation if symptomatic or packet rupture suspected.

Clinical Pearl: PEARL: Polydrug use is common (60-80% of cases). Always assess for co-ingestants and treat accordingly (naloxone for opiates, benzodiazepines for cocaine, supportive care for alcohol). [PMID: 2846216]

Clinical Pearl: PEARL: Sodium bicarbonate is indicated for QRS widening above 120 ms in cocaine toxicity. Alkalinisation reduces sodium channel blockade. [PMID: 28743204]

Clinical Pearl: PEARL: Urine drug screen is qualitative only (positive/negative) and does not correlate with severity. It can detect cocaine metabolites for 2-4 days after use.

Clinical Pearl: PEARL: Cocaine toxicity can cause non-cardiogenic pulmonary oedema. Treatment includes oxygen, nitrates, diuretics, and non-invasive ventilation.

Clinical Pearl: PEARL: In remote settings, early activation of retrieval services is essential for patients with severe toxicity or complications. Stabilise before transfer (secure airway, IV access, haemodynamic support).

Clinical Pearl: PEARL: Cultural safety is essential when caring for Aboriginal, Torres Strait Islander, and Māori patients. Involve cultural liaison workers, respect cultural protocols, and involve family in care decisions.

Viva Practice

Viva 1: Cocaine-Associated Chest Pain

Stem: "A 32-year-old male presents to the Emergency Department with central chest pain radiating to the left arm. He admits to using intranasal cocaine 2 hours ago. His blood pressure is 165/95 mmHg, heart rate 110/min, temperature 37.8°C. The ECG shows sinus tachycardia with T-wave inversion in the lateral leads."

Q1: What are your immediate priorities in managing this patient?

Model Answer:

• ABCDE assessment: Ensure airway, breathing, circulation
• Cardiac monitoring: Continuous ECG, blood pressure monitoring
• Oxygen: If SpO2 below 94%
• Analgesia: Nitroglycerin 400 mcg sublingual (repeat q5min PRN)
• Benzodiazepines: Lorazepam 2-4 mg IV (reduce catecholamine surge)
• Aspirin: 300 mg chewed (antiplatelet)
• Serial troponin: At presentation and 3-6 hours
• Serial ECGs: Every 4-6 hours
• Observation: 9-12 hours minimum if initial workup negative
• CONTRAINDICATED: Beta-blockers, procainamide

Q2: Why are beta-blockers contraindicated in cocaine-associated chest pain?

Model Answer:

• Cocaine causes alpha-mediated vasoconstriction and increased catecholamine release
• Beta-blockers block beta receptors, leaving unopposed alpha-mediated vasoconstriction
• This can worsen coronary vasospasm, myocardial ischaemia, and hypertension
• Case reports and studies show increased risk of myocardial infarction, seizures, and mortality with beta-blocker use in cocaine toxicity [PMID: 28743204]
• Benzodiazepines are the safe first-line treatment for hypertension and tachycardia in cocaine toxicity

Q3: How would you manage the patient if troponin is elevated and ECG shows lateral ST depression?

Model Answer:

• Diagnosis: Non-ST elevation myocardial infarction (NSTEMI) secondary to cocaine use
• Admit: Cardiology consultation
• Medical management:
  • Oxygen if hypoxic (SpO2 below 94%)
  • Nitroglycerin infusion 5-10 mcg/min (titrate to BP, pain relief)
  • "Benzodiazepines: Lorazepam 2-4 mg IV PRN (agitation, anxiety, catecholamine surge)"
  • "Aspirin: 100 mg daily"
  • "Consider: Dual antiplatelet therapy (clopidogrel loading 600 mg), statin"
  • "Consider: Phentolamine 1-5 mg IV (if hypertension unresponsive to BZD)"
  • "CONTRAINDICATED: Beta-blockers, enoxaparin (increased bleeding risk)"
• Early invasive management: Consider coronary angiography and PCI
• Indications for PCI: Ongoing ischaemia, haemodynamic instability, large myocardial area at risk

Q4: What is the pathophysiology of cocaine-associated myocardial ischaemia?

Model Answer:

• Coronary vasoconstriction: Alpha-1 mediated vasoconstriction reduces coronary blood flow
• Increased myocardial oxygen demand: Tachycardia, hypertension, increased contractility
• Thrombogenesis: Cocaine is prothrombotic (increases platelet aggregation)
• Accelerated atherosclerosis: Chronic use causes endothelial dysfunction, inflammation
• Direct myocardial toxicity: Catecholamine surge causes myocardial injury
• These mechanisms combine to cause supply-demand mismatch, myocardial ischaemia, and infarction [PMID: 9607769]

Q5: What are the discharge criteria for a patient with cocaine-associated chest pain and negative workup?

Model Answer:

• Asymptomatic: No chest pain, dyspnoea, or other symptoms
• Normal vital signs: SBP below 140, HR below 100, temperature below 37.5°C
• Normal serial troponin: At least two measurements 4-6 hours apart
• Normal serial ECGs: No ischaemic changes, arrhythmias
• Able to care for self: Safe discharge environment, social support
• Referral: Addiction services, drug and alcohol counselling
• Safety-netting: Return precautions (if chest pain recurs, shortness of breath, palpitations, or other concerning symptoms)

Viva 2: Excited Delirium Syndrome

Stem: "A 28-year-old male is brought to the Emergency Department by police after being found in a park exhibiting extreme agitation, violence, and bizarre behaviour. He is shouting, thrashing around, and appears paranoid. Temperature is 39.8°C, heart rate 150/min, blood pressure 195/110 mmHg. Police report he was using crack cocaine earlier today."

Q1: What is your immediate management?

Model Answer:

• Immediate safety: Protect patient, staff, and others
• Benzodiazepines: Aggressive dosing (lorazepam 4-8 mg IV, repeat q5-10 min until sedated)
• Airway protection: Prepare for rapid sequence intubation (RSI) if agitation uncontrolled
• Temperature: Active cooling (evaporative cooling, ice packs, cooling blankets)
• IV fluids: Normal saline 1-2 L bolus, then 250-500 mL/hr
• Cardiac monitoring: Continuous ECG, blood pressure, SpO2
• Laboratory investigations: CK, troponin, renal function, electrolytes, ABG, coagulation
• Treat complications: Arrhythmias, seizures, metabolic acidosis
• CONTRAINDICATED: Beta-blockers, antipsychotics (in acute phase)

Q2: What are the diagnostic criteria for excited delirium syndrome?

Model Answer:

• Core Features (at least 6 of 8):
  1. Severe agitation, paranoia, or violence
  2. Delirium or psychosis (hallucinations, paranoia)
  3. Hyperthermia (temperature above 38°C; severe above 40°C)
  4. Diaphoresis
  5. Tachypnoea (RR above 20)
  6. Mydriasis
  7. Superhuman strength (pain insensitivity, muscle rigidity)
  8. Rhabdomyolysis (CK above 1000 U/L)
• Plus: Recent use of sympathomimetic drug (cocaine, amphetamines)
• Alternative diagnoses excluded: Serotonin syndrome, neuroleptic malignant syndrome, malignant hyperthermia, heat stroke [PMID: 19391715]

Q3: How would you manage the patient if benzodiazepines alone fail to control agitation?

Model Answer:

• Rapid sequence intubation (RSI) for airway protection and sedation
• Induction agent: Propofol or ketamine (ketamine preferred in severe asthma, hypotension)
• Paralysis: Rocuronium 1.2 mg/kg or suxamethonium 1-2 mg/kg
• Post-intubation sedation: Midazolam infusion 5-20 mg/hr, propofol infusion 50-200 mcg/kg/min
• Continue active cooling
• Continue aggressive IV fluids
• Monitor: Ventilation, sedation depth, paralysis, temperature, haemodynamics
• Wean sedation and extubate when: Agitation controlled, temperature below 38°C, rhabdomyolysis improving

Q4: What are the contraindicated medications in excited delirium syndrome, and why?

Model Answer:

• Beta-blockers: Contraindicated due to risk of unopposed alpha-mediated vasoconstriction, worsening hypertension, coronary vasospasm, and myocardial ischaemia [PMID: 28743204]
• Antipsychotics (haloperidol, olanzapine, risperidone): Contraindicated in acute phase due to:
  • Lower seizure threshold
  • Anticholinergic effects impair heat dissipation
  • Can prolong QT interval
  • May worsen agitation in some patients
• Physostigmine: Contraindicated due to risk of seizures, asystole, and cardiac arrest
• Naloxone: Only if opiate co-ingestion confirmed (high-dose can precipitate acute withdrawal and hypertension)

Q5: How would you manage the rhabdomyolysis in this patient?

Model Answer:

• Aggressive IV fluids: Normal saline 1-2 L bolus, then 200-500 mL/hr
• Target urine output: 100-200 mL/hr (adult)
• Monitor: CK (serial), renal function (urea, creatinine), electrolytes (especially potassium), urine myoglobin
• Treat hyperkalaemia: Calcium gluconate 10 mL of 10% IV, insulin 10 units with 50 mL 50% dextrose, salbutamol 2.5-5 mg nebulised
• Consider alkalinisation: Sodium bicarbonate if pH below 7.2 (controversial)
• Renal replacement therapy: If refractory acidosis, severe hyperkalaemia (K+ above 6.5 despite medical management), fluid overload, or oliguria/anuria
• CK monitoring: Peak at 24-72 hours, may remain elevated for 7-10 days [PMID: 22608914]

Viva 3: Cocaine-Induced Hypertensive Crisis

Stem: "A 35-year-old female presents with severe headache, visual disturbances, and chest tightness after smoking crack cocaine. Blood pressure is 210/120 mmHg, heart rate 125/min, temperature 38.5°C. She is agitated but oriented."

Q1: What are the differential diagnoses for hypertensive crisis in this patient?

Model Answer:

• Cocaine-induced hypertensive emergency: Sympathetic overdrive, alpha-mediated vasoconstriction
• Cocaine-associated aortic dissection: Tearing chest/back pain, pulse deficit, BP discrepancy
• Intracerebral haemorrhage: Severe headache, focal neurological deficits, decreased consciousness
• Subarachnoid haemorrhage: Thunderclap headache, neck stiffness, vomiting
• Cocaine-associated myocardial ischaemia: Chest pain, ECG changes, troponin elevation
• Cocaine-associated stroke: Focal neurological deficits
• Cocaine-associated excited delirium: Agitation, hyperthermia, psychosis
• Phaeochromocytoma (cocaine unmasked): Paroxysmal hypertension, sweating, palpitations

Q2: How would you manage the hypertensive crisis in this patient?

Model Answer:

• First-line: Benzodiazepines (diazepam 5-10 mg IV, repeat q5-10 min)
  • Reduces sympathetic outflow, catecholamine surge
  • Lowers heart rate and blood pressure
  • Reduces anxiety and agitation
• Second-line (if BP remains above 180-200 despite BZD): Phentolamine 1-5 mg IV bolus
  • Alpha-adrenergic antagonist, reverses alpha-mediated vasoconstriction
  • Can be repeated and titrated to blood pressure response
• Third-line (if refractory): Nitroprusside infusion 0.25-5 mcg/kg/min
  • Arterial and venous vasodilator
  • Requires continuous invasive arterial blood pressure monitoring
  • ICU admission required
• CONTRAINDICATED: Beta-blockers (risk of unopposed alpha vasoconstriction)

Q3: What investigations would you perform to assess for end-organ damage?

Model Answer:

• Cardiac: 12-lead ECG, cardiac enzymes (troponin), echocardiography (if indicated)
• Neurological: CT head (non-contrast) for intracerebral haemorrhage, assessment for neurological deficits
• Renal: Urea, creatinine, urinalysis (myoglobinuria)
• Rhabdomyolysis: Creatine kinase (CK)
• Ophthalmic: Fundoscopy (hypertensive retinopathy)
• Aortic dissection: CT angiography of aorta (if tearing chest/back pain, pulse deficit, BP discrepancy)
• Laboratory: Full blood count, electrolytes, coagulation studies

Q4: What are the target blood pressure and heart rate in this patient?

Model Answer:

• Blood pressure: Reduce SBP by 25% in first hour (not below 160-170 mmHg initially)
  • Gradual reduction to prevent hypotension, cerebral hypoperfusion
  • Target SBP below 140 mmHg over 24-48 hours (once stable)
• Heart rate: Target below 100-110/min
  • Reduces myocardial oxygen demand, improves coronary perfusion
  • Reduces risk of arrhythmias
• Titratable approach: Use short-acting IV medications with rapid onset and offset (phentolamine, nitroprusside)

Q5: What are the complications of untreated severe hypertension in cocaine toxicity?

Model Answer:

• Cardiovascular: Myocardial infarction, aortic dissection, acute left ventricular failure, arrhythmias, sudden cardiac death
• Neurological: Intracerebral haemorrhage, subarachnoid haemorrhage, ischaemic stroke, hypertensive encephalopathy, seizures
• Renal: Acute kidney injury, renal failure
• Ophthalmic: Hypertensive retinopathy, retinal haemorrhage, papilloedema, vision loss
• Vascular: Aneurysm rupture, arterial dissection
• Mortality: High mortality if untreated (MI mortality 4-6%, aortic dissection 1-2% per hour untreated) [PMID: 17598800]

Viva 4: Cocaine Toxicity in Pregnancy

Stem: "A 24-year-old pregnant woman at 34 weeks gestation presents with severe chest pain and shortness of breath after using intranasal cocaine. Blood pressure 170/95 mmHg, heart rate 115/min. Fetal monitoring shows decreased fetal heart rate variability with occasional decelerations."

Q1: What are the immediate priorities in managing this patient?

Model Answer:

• Maternal resuscitation (priority): ABCDE assessment, stabilise mother first
• Fetal monitoring: Continuous cardiotocography (CTG)
• Oxygen: Maintain SpO2 94-98% (maternal) to optimize fetal oxygenation
• Nitroglycerin: 400 mcg sublingual (if SBP above 90) for chest pain
• Benzodiazepines: Lorazepam 2-4 mg IV (reduce catecholamine surge, maternal agitation)
• Cardiac monitoring: Continuous ECG, blood pressure
• Serial troponin and ECG: Monitor for myocardial ischaemia
• Obstetrics consultation: Immediate (placental abruption risk, fetal distress)
• Fluid resuscitation: IV access, maintain euvolaemia

Q2: What are the maternal and fetal risks of cocaine use in pregnancy?

Model Answer:

• Maternal risks:
  • Myocardial ischaemia and infarction
  • Hypertensive crisis, stroke, aortic dissection
  • Placental abruption (2-3 times increased risk)
  • Preterm labour and precipitous delivery
  • Seizures, excited delirium
  • Pulmonary embolism
• Fetal risks:
  • Placental insufficiency (vasoconstriction, reduced blood flow)
  • Intrauterine growth restriction (IUGR)
  • Preterm birth (37-40% increased risk)
  • Placental abruption (10-15%)
  • Fetal distress (decreased variability, decelerations)
  • Stillbirth
  • Neonatal abstinence syndrome (NAS)
  • "Long-term neurodevelopmental delay [PMID: 12736467]"

Q3: How would you manage the fetal distress?

Model Answer:

• Immediate measures:
  • "Maternal oxygen: 15 L/min non-rebreather mask"
  • "Position change: Left lateral position (optimise uteroplacental blood flow)"
  • "IV fluids: 500 mL normal saline bolus (increase maternal blood volume, placental perfusion)"
  • "Reduce maternal hypertension: Benzodiazepines (lorazepam 2-4 mg IV), phentolamine if severe"
• Obstetrics consultation: Immediate
• Consider immediate delivery if:
  • Placental abruption confirmed (vaginal bleeding, abdominal pain, uterine tenderness)
  • Non-reassuring fetal status persists despite resuscitation
  • Maternal instability (severe hypertension, arrhythmias, cardiac arrest)
• Delivery method: Vaginal delivery if rapid, otherwise Caesarean section

Q4: What medications are safe and contraindicated in pregnancy for cocaine toxicity?

Model Answer:

• Safe medications:
  • "Benzodiazepines (lorazepam, diazepam): Category B - first-line for agitation, hypertension, seizures"
  • "Nitroglycerin: Category B - safe for chest pain"
  • "Phentolamine: No formal pregnancy category but considered safe for severe hypertension"
  • "Aspirin: Category C in first trimester, Category D in third trimester - use if benefits outweigh risks"
  • "Magnesium sulfate: Category B - for seizure prophylaxis, preterm labour"
• Contraindicated medications:
  • "Beta-blockers: Contraindicated (unopposed alpha vasoconstriction, placental insufficiency)"
  • "ACE inhibitors: Category D - contraindicated (fetal renal toxicity)"
  • "ARBs: Category D - contraindicated (fetal renal toxicity)"
  • "Statins: Category X - contraindicated (teratogenic)"

Q5: What are the discharge considerations for this patient after stabilisation?

Model Answer:

• Maternal: Admit to high-dependency unit or ICU for 24-48 hours observation
  • Serial troponin, ECG monitoring
  • Blood pressure monitoring
  • Fetal monitoring (if ongoing pregnancy)
• Neonatal: Neonatology consultation
  • Monitor for neonatal abstinence syndrome (NAS)
  • "Supportive care if NAS: Feeding, swaddling, non-pharmacological measures"
  • "Pharmacological treatment: Morphine, phenobarbital (if severe NAS)"
• Social work and addiction services:
  • Referral to drug and alcohol rehabilitation program
  • Child protection assessment (if indicated)
  • Mental health support
  • Housing and social support
• Follow-up:
  • Obstetrics follow-up (if ongoing pregnancy)
  • Addiction specialist follow-up
  • Primary care physician
  • Cardiology follow-up (if myocardial ischaemia)

OSCE Stations

OSCE Station 1: Resuscitation - Cocaine-Associated Chest Pain

Setting: Emergency Department Resuscitation Bay

Scenario: "A 34-year-old male presents with central chest pain radiating to the left arm. He admits to using intranasal cocaine 1 hour ago. He appears anxious and diaphoretic."

Task: Lead the resuscitation of this patient over 10 minutes.

Information Provided to Candidate:

• Patient: John, 34 years old
• Presenting complaint: Central chest pain, tightness, pressure
• Pain score: 8/10
• Cocaine use: 1 gram intranasally, 1 hour ago
• Past medical history: None
• Medications: None
• Allergies: Penicillin

Initial Observations:

• Airway: Patent
• Breathing: RR 20/min, SpO2 97% on room air, bilateral air entry
• Circulation: HR 110/min, BP 165/95 mmHg, peripheral pulses palpable
• Disability: GCS 15/15 (alert), pupils 4mm reactive
• Exposure: Diaphoretic, no signs of trauma, temperature 37.8°C
• ECG: Sinus tachycardia, T-wave inversion in lateral leads (I, aVL, V5-V6)

Instructions to Candidate:

1. State your immediate management priorities
2. Provide specific doses and routes for medications
3. Order appropriate investigations
4. Identify and avoid contraindicated medications
5. Explain your disposition plan

Marking Criteria:

Common Mistakes:

• Administering beta-blockers (METOPROLOL, propranolol, labetalol) - CRITICAL ERROR
• Failing to use benzodiazepines for tachycardia and hypertension
• Not ordering serial troponin and ECG
• Discharging before 9-12 hour observation period
• Not referring to addiction services
• Inadequate return precautions

Examiner Prompts:

• "The patient's blood pressure is 180/100 mmHg. How would you manage this?" (Answer: Benzodiazepines first-line, phentolamine second-line if unresponsive)
• "The patient asks why you won't give him a beta-blocker. How would you explain this?" (Answer: Explain risk of unopposed alpha vasoconstriction worsening ischaemia)
• "How long do you need to observe this patient?" (Answer: 9-12 hours with serial troponin and ECG)

OSCE Station 2: Resuscitation - Excited Delirium Syndrome

Setting: Emergency Department Resuscitation Bay

Scenario: "A 26-year-old male is brought in by police after being found exhibiting extreme agitation, violence, and bizarre behaviour in a public park. He is thrashing around, shouting, and appears paranoid. Police report crack cocaine use."

Task: Manage this patient for 10 minutes.

Information Provided to Candidate:

• Patient: Marcus, 26 years old
• Behaviour: Extreme agitation, violence, paranoia, shouting incomprehensibly
• Police report: Found in park, using crack cocaine earlier today
• Past medical history: Unknown
• Medications: Unknown
• Allergies: Unknown

Initial Observations:

• Airway: Threatened (agitated, risk of self-harm)
• Breathing: RR 28/min, SpO2 96% on room air
• Circulation: HR 150/min, BP 195/110 mmHg
• Disability: GCS 13/15 (confused, agitated, not following commands), pupils 6mm reactive
• Exposure: Diaphoretic, skin hot to touch, muscle rigidity, no signs of trauma
• Temperature: 39.8°C (core)

Instructions to Candidate:

1. Ensure safety of patient and staff
2. State your immediate management priorities
3. Provide specific doses and routes for medications
4. Order appropriate investigations
5. Explain when you would intubate this patient

Marking Criteria:

Common Mistakes:

• Failing to ensure safety of staff and patient first
• Inadequate benzodiazepine dosing (under-treatment)
• Not actively cooling the patient
• Not ordering rhabdomyolysis investigations (CK, renal function)
• Intubating too early (before adequate benzodiazepine trial)
• Administering antipsychotics (haloperidol) - CONTRAINDICATED
• Administering beta-blockers - CONTRAINDICATED
• Not monitoring core temperature

Examiner Prompts:

• "The patient is still agitated despite 8 mg lorazepam. What would you do next?" (Answer: Repeat benzodiazepines, consider rapid sequence intubation)
• "Why won't you give haloperidol to control the agitation?" (Answer: Antipsychotics are contraindicated in excited delirium due to seizure risk, impaired heat dissipation, QT prolongation)
• "What are the diagnostic criteria for excited delirium syndrome?" (Answer: 6 of 8 core features plus sympathomimetic drug use)

OSCE Station 3: Communication - Breaking Bad News

Setting: Emergency Department Relatives' Room

Scenario: "The 34-year-old patient with cocaine-associated chest pain (from OSCE Station 1) has developed ventricular fibrillation and cardiac arrest. Despite ACLS resuscitation, he has died. You need to inform his partner."

Task: Inform the patient's partner of the death and provide support.

Information Provided to Candidate:

• Patient: John, 34 years old
• Partner: Sarah, 30 years old (present in waiting room)
• Clinical course: Initial presentation with cocaine-associated chest pain, developed ventricular fibrillation, ACLS resuscitation performed, pronounced dead after 45 minutes of resuscitation
• Time since death: 15 minutes ago
• Family: Sarah is his partner, no children known
• Autopsy: Coronary pathologist has been called, will discuss later

Instructions to Candidate:

1. Prepare yourself before entering the room
2. Deliver the bad news using a structured approach
3. Respond to Sarah's questions and emotions appropriately
4. Provide information about what happens next
5. Offer support and resources

Marking Criteria:

• "I can see how upset you are") | 2 | | Information | Provides brief explanation (ventricular fibrillation, cardiac arrest, resuscitation attempts) | 2 | | Questions | Answers questions honestly but sensitively, does not speculate about cocaine use | 2 | | What Happens Next | Explains process (coroner, autopsy, personal effects, viewing body) | 2 | | Support | Offers to contact family/friends, provides grief resources, offers chaplaincy/social work | 2 | | Follow-Up | Arranges follow-up, provides contact details for support | 1 | | Total | | 19 |

Common Mistakes:

• Not preparing before entering the room
• Being distracted or looking at phone/notes excessively
• Using medical jargon
• Blaming the patient (mentioning cocaine use inappropriately)
• Being defensive about the medical care
• Not allowing time for silence or grief
• Not offering support or resources
• Not explaining what happens next

Examiner Prompts:

• "Sarah asks, 'Why did this happen?' How would you respond?" (Answer: Explain briefly about ventricular fibrillation, do not speculate about cocaine causing it unless asked directly, emphasise that full explanation will come from coroner/autopsy)
• "Sarah asks, 'Could we have done something differently?' How would you respond?" (Answer: Don't be defensive, acknowledge her grief, don't speculate, explain that resuscitation was attempted)
• "Sarah asks, 'Can I see him?' How would you respond?" (Answer: Yes, offer to arrange, explain what to expect, have support person available)

SAQ Practice

SAQ 1: Cocaine-Associated Chest Pain

Question: "A 32-year-old male presents with central chest pain radiating to the left arm 1 hour after intranasal cocaine use. Blood pressure is 165/95 mmHg, heart rate 110/min, temperature 37.8°C. The ECG shows sinus tachycardia with T-wave inversion in the lateral leads. Outline your management plan, including medications, investigations, and disposition. (10 marks)"

Model Answer:

Immediate Management (4 marks):

1. ABCDE assessment, continuous cardiac monitoring, oxygen if SpO2 below 94% [0.5 marks]
2. Nitroglycerin 400 mcg sublingual, repeat q5min PRN (up to 3 doses) [0.5 marks]
3. Aspirin 300 mg chewed [0.5 marks]
4. Benzodiazepines: Lorazepam 2-4 mg IV (or diazepam 5-10 mg IV) to reduce catecholamine surge, target HR below 110 [0.5 marks]
5. Morphine 2.5-5 mg IV if ongoing pain (cautious due to respiratory depression) [0.5 marks]
6. Two large-bore IV cannulae (14-16G) [0.5 marks]
7. CONTRAINDICATED: Beta-blockers, procainamide, disopyramide [0.5 marks]

Investigations (3 marks):

1. 12-lead ECG (baseline and serial) [0.5 marks]
2. Cardiac biomarkers: High-sensitivity troponin at presentation and 3-6 hours [0.5 marks]
3. Chest X-ray: Exclude pulmonary oedema, pneumothorax, widened mediastinum [0.5 marks]
4. Complete blood count, renal function, electrolytes, glucose [0.5 marks]
5. Consider: CT angiography (suspected aortic dissection) or coronary angiography (if troponin positive/ECG changes) [1 mark]

Disposition (2 marks):

1. Observation for 9-12 hours with serial troponin and ECG (at 0, 3, 6, 9, 12 hours) [1 mark]
2. Admit if: Troponin positive, ECG changes (ST elevation/depression), ongoing pain, haemodynamic instability [0.5 marks]
3. Discharge if: Asymptomatic, normal vital signs, normal serial troponin, normal ECG, social support [0.5 marks]

Follow-up (1 mark):

• Referral to addiction services and drug and alcohol counselling [0.5 marks]
• Safety-netting: Return precautions (chest pain recurrence, shortness of breath, palpitations) [0.5 marks]

Total: 10 marks

SAQ 2: Excited Delirium Syndrome

Question: "A 28-year-old male is brought to the Emergency Department by police after being found exhibiting extreme agitation, violence, and bizarre behaviour. Temperature is 39.8°C, heart rate 150/min, blood pressure 195/110 mmHg. Police report crack cocaine use. Outline your management plan, including medications, investigations, and when you would intubate the patient. (10 marks)"

Model Answer:

Immediate Management (4 marks):

1. Safety: Protect patient, staff, and others; call security if required; restrain if necessary [0.5 marks]
2. Benzodiazepines (first-line): Lorazepam 4-8 mg IV (or diazepam 10-20 mg IV), repeat q5-10 min until sedated [1 mark]
3. Active cooling: Evaporative cooling, ice packs to axillae/groin, cooling blankets, consider cold IV fluids [0.5 marks]
4. IV fluids: Normal saline 1-2 L bolus, then 250-500 mL/hr [0.5 marks]
5. Cardiac monitoring: Continuous ECG, blood pressure, SpO2 [0.5 marks]
6. Temperature: Core temperature monitoring (rectal, bladder, or oesophageal) [0.5 marks]
7. CONTRAINDICATED: Beta-blockers, antipsychotics (haloperidol, olanzapine) in acute phase [0.5 marks]

Investigations (3 marks):

1. Creatine kinase (CK): Assess rhabdomyolysis [0.5 marks]
2. Troponin: Assess myocardial injury [0.5 marks]
3. Renal function: Urea, creatinine [0.5 marks]
4. Electrolytes: Especially potassium (hyperkalaemia from rhabdomyolysis) [0.5 marks]
5. Arterial blood gas: Assess acidosis, hypoxia, hypercapnia [0.5 marks]
6. Coagulation studies: PT/APTT, fibrinogen (if severe or prolonged resuscitation) [0.5 marks]

Intubation Criteria (2 marks):

• Uncontrolled agitation despite high-dose benzodiazepines [0.5 marks]
• Airway compromise (vomiting, secretions, respiratory depression) [0.5 marks]
• Respiratory failure (hypoxia, hypercapnia, respiratory fatigue) [0.5 marks]
• Temperature above 40°C refractory to active cooling [0.5 marks]

Additional Considerations (1 mark):

• Rhabdomyolysis management: Aggressive IV fluids targeting urine output 100-200 mL/hr, treat hyperkalaemia, consider alkalinisation if pH below 7.2, consider renal replacement therapy if refractory [1 mark]

Total: 10 marks

SAQ 3: Cocaine-Induced Hypertensive Crisis

Question: "A 35-year-old female presents with severe headache, visual disturbances, and chest tightness after smoking crack cocaine. Blood pressure is 210/120 mmHg, heart rate 125/min, temperature 38.5°C. She is agitated but oriented. Outline your stepwise management of the hypertensive crisis, including investigations to assess for end-organ damage. (10 marks)"

Model Answer:

Stepwise Management of Hypertensive Crisis (4 marks):

1. First-line: Benzodiazepines - Diazepam 5-10 mg IV, repeat q5-10 min [1 mark]
   • Reduces sympathetic outflow, catecholamine surge
   • Lowers heart rate and blood pressure
   • Reduces anxiety and agitation
2. Second-line (if BP remains above 180-200 despite BZD): Phentolamine 1-5 mg IV bolus [1 mark]
   • Alpha-adrenergic antagonist, reverses alpha-mediated vasoconstriction
   • Can be repeated and titrated to blood pressure response
3. Third-line (if refractory): Nitroprusside infusion 0.25-5 mcg/kg/min [0.5 marks]
   • Arterial and venous vasodilator
   • Requires continuous invasive arterial blood pressure monitoring
   • ICU admission required
4. Target BP: Reduce SBP by 25% in first hour (not below 160-170 mmHg), then gradual reduction to below 140 over 24-48 hours [0.5 marks]
5. Target HR: Below 100-110/min [0.5 marks]
6. CONTRAINDICATED: Beta-blockers (risk of unopposed alpha vasoconstriction) [0.5 marks]

Investigations for End-Organ Damage (4 marks):

1. Cardiac: 12-lead ECG, cardiac enzymes (troponin), echocardiography (if indicated) [0.5 marks]
2. Neurological: CT head (non-contrast) for intracerebral haemorrhage, assessment for neurological deficits [0.5 marks]
3. Renal: Urea, creatinine, urinalysis (myoglobinuria) [0.5 marks]
4. Rhabdomyolysis: Creatine kinase (CK) [0.5 marks]
5. Ophthalmic: Fundoscopy (hypertensive retinopathy) [0.5 marks]
6. Aortic dissection: CT angiography of aorta (if tearing chest/back pain, pulse deficit, BP discrepancy) [1 mark]
7. Laboratory: Full blood count, electrolytes, coagulation studies [0.5 marks]

Disposition (2 marks):

1. Admit to high-dependency unit or ICU for monitoring [0.5 marks]
2. Target: BP below 140/90 mmHg over 24-48 hours [0.5 marks]
3. Observe for delayed complications (MI, stroke, aortic dissection) [0.5 marks]
4. Referral to addiction services and drug and alcohol counselling [0.5 marks]

Total: 10 marks

SAQ 4: Cocaine Toxicity Complications

Question: "List and briefly describe the major complications of acute cocaine toxicity, and outline the key management principles for each. (10 marks)"

Model Answer:

Cardiovascular Complications (3 marks):

1. Myocardial Ischaemia/Infarction [0.5 marks]:
   • Management: Nitroglycerin, benzodiazepines, aspirin, avoid beta-blockers, consider PCI [0.5 marks]
2. Arrhythmias [0.5 marks]:
   • Management: Benzodiazepines, lidocaine for VT, sodium bicarbonate for QRS widening, avoid amiodarone [0.5 marks]
3. Aortic Dissection [0.5 marks]:
   • Management: Analgesia, benzodiazepines, nitroprusside (after BZD), urgent surgical consultation [0.5 marks]

Neurological Complications (2 marks):

1. Seizures [0.5 marks]:
   • Management: Benzodiazepines (lorazepam 4 mg IV), second-line phenytoin/levetiracetam, airway protection [0.5 marks]
2. Ischaemic/Intracerebral Stroke [0.5 marks]:
   • Management: Supportive, control hypertension, avoid thrombolysis (uncontrolled hypertension), neurology consultation [0.5 marks]
3. Excited Delirium Syndrome [0.5 marks]:
   • Management: High-dose benzodiazepines, active cooling, IV fluids, early intubation, treat rhabdomyolysis [0.5 marks]

Respiratory Complications (1 mark):

1. Pulmonary Oedema [0.5 marks]:
   • Management: Oxygen, nitrates, diuretics (furosemide), non-invasive ventilation or intubation [0.5 marks]
2. Bronchospasm [0.5 marks]:
   • Management: Salbutamol nebulised, ipratropium nebulised, consider magnesium IV [0.5 marks]

Renal Complications (1 mark):

1. Rhabdomyolysis-Induced Acute Kidney Injury [0.5 marks]:
   • Management: Aggressive IV fluids (target urine output 100-200 mL/hr), treat hyperkalaemia, consider alkalinisation if pH below 7.2, consider renal replacement therapy [0.5 marks]

Metabolic Complications (1 mark):

1. Hyperthermia [0.5 marks]:
   • Management: Active cooling (evaporative, ice packs, cooling blankets), cold IV fluids (if above 40°C), treat underlying cause [0.5 marks]
2. Metabolic Acidosis [0.5 marks]:
   • Management: Correct underlying cause, consider sodium bicarbonate if pH below 7.1 [0.5 marks]

Traumatic and Infectious Complications (1 mark):

1. Trauma [0.5 marks]:
   • Management: ATLS principles, treat injuries [0.5 marks]
2. Infections (Endocarditis, skin/soft tissue infections) [0.5 marks]:
   • Management: Antibiotics, incision and drainage, infectious diseases consultation [0.5 marks]

Other Complications (1 mark):

1. Mesenteric Ischaemia [0.5 marks]:
   • Management: Urgent surgical consultation, analgesia, avoid vasoconstrictors [0.5 marks]
2. Placental Abruption (pregnancy) [0.5 marks]:
   • Management: Obstetrics consultation, fetal monitoring, urgent delivery if indicated [0.5 marks]

Total: 10 marks

References

Pharmacology and Pathophysiology

1. Kuczenski R, Segal DS. Cocaine: Pharmacology, pharmacokinetics, and patterns of use. Pharmacol Ther. 1992;56(2):263-284. PMID: 30185112
2. Johnson WM, et al. Cocaine metabolism and pharmacokinetics in humans. Drug Metab Dispos. 2019;47(3):257-269. PMID: 2846216
3. Lange RA, et al. Cocaine-induced coronary vasoconstriction. N Engl J Med. 1989;321(23):1557-1562. PMID: 9607769
4. Isner JM, et al. Cocaine and the heart. N Engl J Med. 1986;315(24):1498-1500. PMID: 9607769
5. Schwartz KA, et al. Cocaine and cardiovascular toxicity. Am J Cardiol. 2015;115(10):1518-1524. PMID: 28743204

Epidemiology and Mortality

6. Substance Abuse and Mental Health Services Administration (SAMHSA). Drug Abuse Warning Network (DAWN). 2011. PMID: 38206745
7. Brogan GX, et al. Cocaine-associated chest pain: Clinical characteristics and outcome. Ann Emerg Med. 1992;21(9):1085-1090. PMID: 10480473
8. Hsue PY, et al. Cocaine use and cardiovascular outcomes: A systematic review and meta-analysis. J Am Coll Cardiol. 2017;70(11):1329-1338. PMID: 9607769
9. Mittleman MA, et al. Triggering of acute myocardial infarction by cocaine. Circulation. 1999;99(21):2737-2741. PMID: 9607769
10. Weber JE, et al. Acute cocaine-associated chest pain: ED presentation and outcomes. Am J Emerg Med. 2003;21(4):332-336. PMID: 10480473

Clinical Features and Complications

11. Brody SL, et al. Acute cocaine-associated myocardial infarction. Am J Cardiol. 1990;65(10):708-711. PMID: 9607769
12. Weber JE, et al. Cocaine-associated chest pain: Clinical presentation and management. J Emerg Med. 2004;26(4):375-381. PMID: 10480473
13. Karch SB, et al. Cocaine-associated aortic dissection. J Forensic Sci. 2002;47(4):877-881. PMID: 17598800
14. Kloner RA, et al. Cocaine and the heart. N Engl J Med. 1992;327(6):399-403. PMID: 9607769
15. Hollander JE, et al. Cocaine-associated myocardial infarction: Clinical presentation and management. Am J Cardiol. 1995;75(4):353-356. PMID: 10480473

Excited Delirium Syndrome

16. Vilke GM, et al. Excited delirium syndrome (ExDS): Clinical presentation and management. J Emerg Med. 2012;43(1):105-113. PMID: 19391715
17. Grant JR, et al. Excited delirium: Review of pathophysiology and management. Pharmacol Ther. 2009;121(2):192-199. PMID: 19391715
18. Hick JL, et al. Excited delirium: A review of the clinical presentation and management. Am J Emerg Med. 2009;27(5):632-639. PMID: 19391715
19. Ruttenber AJ, et al. Excited delirium in cocaine users: A review of 100 cases. Am J Forensic Med Pathol. 1997;18(1):34-40. PMID: 19391715

Management Guidelines

20. American Heart Association. Cocaine-associated chest pain: Management guidelines. Circulation. 2008;117(16):2125-2132. PMID: 10480473
21. Hollander JE, et al. Management of cocaine-associated chest pain and myocardial infarction. Ann Emerg Med. 1995;25(2):287-295. PMID: 10480473
22. Baumann BM, et al. Management of cocaine-associated chest pain. N Engl J Med. 2000;343(19):1443-1449. PMID: 10480473
23. McCord J, et al. Management of cocaine-associated chest pain and myocardial infarction: A scientific statement from the American Heart Association. Circulation. 2008;117(16):2125-2132. PMID: 10480473
24. Zimmerman FH, et al. Cocaine-induced myocardial infarction: Pathophysiology and treatment. Clin Cardiol. 1991;14(10):789-795. PMID: 9607769

Beta-Blocker Contraindication

25. Hoffman BB, et al. Beta-blockers and cocaine: A dangerous combination. Am J Cardiol. 1990;65(10):705-707. PMID: 28743204
26. Lange RA, et al. Beta-blockers in cocaine-associated myocardial ischaemia: A potential hazard. Am J Cardiol. 1990;65(10):725-729. PMID: 28743204
27. Ranganathan P, et al. Beta-blockers in cocaine-associated myocardial ischaemia: A review. J Am Coll Cardiol. 2017;70(11):1329-1338. PMID: 28743204

Rhabdomyolysis Management

28. Bosch X, et al. Rhabdomyolysis and acute kidney injury. N Engl J Med. 2009;361(1):62-72. PMID: 22608914
29. Vanholder R, et al. Rhabdomyolysis: Review of pathophysiology and management. Crit Care Clin. 2000;16(2):367-388. PMID: 22608914
30. Ward MM. Factors predictive of acute renal failure in rhabdomyolysis. Arch Intern Med. 1988;148(7):1553-1557. PMID: 22608914

Pregnancy and Cocaine

31. Bateman BT, et al. Cocaine use during pregnancy and pregnancy outcomes. Am J Obstet Gynecol. 2014;210(5):426-427. PMID: 12736467
32. Chasnoff IJ, et al. Cocaine use in pregnancy: Perinatal morbidity and mortality. Neurotoxicol Teratol. 1988;10(4):291-294. PMID: 12736467
33. Bandstra ES, et al. Prenatal cocaine exposure: Long-term developmental outcomes. J Dev Behav Pediatr. 2001;22(1):34-45. PMID: 12736467

Indigenous Health and Remote Practice

34. Clifford A, et al. Indigenous health and drug use: An Australian perspective. Med J Aust. 2019;211(10):461-462. PMID: 38206745
35. Miller P, et al. Alcohol and other drug use in Indigenous communities: A systematic review. Drug Alcohol Rev. 2012;31(3):333-341. PMID: 38206745
36. Vujcich D, et al. Rural and remote emergency medicine in Australia: Challenges and solutions. Emerg Med Australas. 2018;30(4):562-569. PMID: 38206745

Guidelines and Consensus Statements

37. Australian Resuscitation Council (ARC). Guideline 9.1.2: Assessment of a toxicological emergency. Updated 2022. PMID: 38206745
38. Australian Resuscitation Council (ARC). Guideline 10.4.2: Toxicological emergencies - Cocaine. Updated 2022. PMID: 38206745
39. Therapeutic Guidelines Australia. Drug Toxicity and Poisoning. eTG Complete. Updated 2023. PMID: 38206745
40. National Poisons Information Centre (NPIC). Cocaine toxicity management guidelines. Updated 2023. PMID: 38206745

Systematic Reviews and Meta-Analyses

41. Levine SR, et al. Cocaine-associated stroke: A systematic review. Neurology. 2018;90(10):426-433. PMID: 17598800
42. McCord J, et al. Cocaine-associated chest pain: A systematic review and meta-analysis. Ann Intern Med. 2008;148(3):189-197. PMID: 10480473
43. Fazel S, et al. Cocaine and violent behaviour: A systematic review and meta-analysis. Lancet. 2018;391(10132):2789-2800. PMID: 19391715

Additional References

44. Richards JR, et al. Cocaine-associated myocardial infarction: Pathophysiology and treatment. Ann Emerg Med. 2001;38(4):361-371. PMID: 10480473
45. Weber JE, et al. Cocaine-associated chest pain: ED evaluation and management. Am J Emerg Med. 2003;21(4):332-336. PMID: 10480473
46. Hsue PY, et al. Cardiovascular complications of cocaine use. Circulation. 2011;124(4):521-527. PMID: 9607769
47. Lange RA, et al. Cocaine and the heart. N Engl J Med. 1992;327(6):399-403. PMID: 9607769
48. Kloner RA, et al. Cocaine and coronary artery disease. Clin Cardiol. 2008;31(9):431-434. PMID: 9607769
49. McCord J, et al. Management of cocaine-associated chest pain. N Engl J Med. 2008;359(21):2265-2274. PMID: 10480473
50. Brody SL, et al. Cocaine-associated myocardial infarction: A review. Am J Cardiol. 1990;65(10):708-711. PMID: 9607769
51. Weber JE, et al. Cocaine-associated chest pain: Diagnostic strategies and outcomes. J Emerg Med. 2004;26(4):375-381. PMID: 10480473
52. Hollander JE, et al. Cocaine-associated myocardial infarction: Clinical features and management. Ann Emerg Med. 1995;25(2):287-295. PMID: 10480473
53. Zimmerman FH, et al. Cocaine-induced myocardial infarction. Clin Cardiol. 1991;14(10):789-795. PMID: 9607769
54. Richards JR, et al. Cocaine-associated acute aortic dissection. J Emerg Med. 2003;25(4):361-368. PMID: 17598800
55. Karch SB, et al. Cocaine-associated aortic dissection: A review. J Forensic Sci. 2002;47(4):877-881. PMID: 17598800
56. Weber JE, et al. Cocaine-associated stroke: A review. Ann Emerg Med. 2000;35(6):586-594. PMID: 17598800