Emergency Medicine · Toxicology
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Excited delirium is triggered by sympathomimetic overdose (cocaine, meth, PCP, bath salts), classically in young males.
The classic tetrad is agitation/combativeness, hyperthermia (>40C), tachycardia, and superhuman strength with profound diaphoresis and inappropriate clothing removal.
IM ketamine is the first-line agent for rapid chemical sedation due to its 1-3 minute onset and preservation of airway reflexes; alternatives are IM midazolam or IM haloperidol.
Physical restraints must be minimized or removed after sedation to prevent asphyxia and sudden cardiac death during struggle.
It is a clinical diagnosis of exclusion; the first step is a bedside capillary glucose to rule out hypoglycemia.
Workup includes an ECG for QT prolongation and a creatine kinase for rhabdomyolysis, plus a BMP/ABG for metabolic acidosis and hyperkalemia.
Treat hyperthermia with evaporative cooling and rhabdomyolysis with aggressive IV fluids to prevent fatal arrhythmia and renal failure.
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A 24-year-old man is brought in by police after running naked through traffic and fighting bystanders. He is profoundly agitated, diaphoretic, and exhibits remarkable strength against four officers restraining him. His temperature is 40.8C, heart rate is 148/min, and bedside glucose is 96 mg/dL. Witnesses report he had been using cocaine.
Which of the following is the most appropriate next step in management?
IM ketamine for chemical sedation
Excited delirium requires rapid chemical sedation to halt the catecholamine surge and physical struggle that drive lethal hyperthermia, acidosis, and arrhythmia; IM ketamine has the fastest onset while preserving airway reflexes. Prolonged physical restraint without sedation risks asphyxia and sudden cardiac death.
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Etiology / Epidemiology
Triggered by sympathomimetic overdose (cocaine, meth, PCP, bath salts) or severe psychiatric non-compliance, predominantly in young males.
Clinical Manifestations
Classic tetrad of agitation/combativeness, hyperthermia, tachycardia, and superhuman strength with profound diaphoresis.
Diagnosis
Clinical diagnosis of exclusion; must rapidly rule out hypoglycemia, hypoxia, and CNS infection.
Treatment
Immediate chemical sedation with IM ketamine or IM midazolam; avoid physical restraints to prevent sudden cardiac death.
Prognosis
High risk of fatal arrhythmia, rhabdomyolysis, and acidosis if not rapidly sedated and cooled.
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Epidemiology & Etiology
Primarily seen in the prehospital or emergency department setting involving young males. Often precipitated by illicit substance use, particularly sympathomimetics (cocaine, methamphetamine), dissociative anesthetics (PCP), or synthetic cathinones (bath salts). Can also occur in patients with undertreated psychiatric disorders (schizophrenia, bipolar mania) or medication non-adherence. Represents a true medical emergency with a high risk of sudden cardiac death during physical restraint.
Pertinent Anatomy
Involves the central nervous system, specifically the striatum and hypothalamus, where neurotransmitter dysregulation alters thermoregulation and motor control. Massive sympathetic outflow directly impacts the myocardium, increasing oxygen demand and predisposing to fatal arrhythmias. Skeletal muscle overexertion against restraints leads to massive cellular breakdown.
Pathophysiology
Driven by a massive catecholamine surge from sympathomimetic toxicity leading to profound autonomic hyperactivity. Massive catecholamine surge causes severe tachycardia, vasoconstriction, and impaired heat dissipation resulting in hyperthermia. Prolonged physical struggle against restraints combined with sympathetic overdrive leads to severe lactic acidosis and rhabdomyolysis. The combination of acidemia, hyperkalemia, and catecholamine toxicity culminates in cardiovascular collapse.
Clinical Manifestations
Patients present with profound hyperactive delirium, severe agitation, and superhuman strength making them incredibly resistant to pain. Autonomic instability is classic, featuring severe tachycardia, profound diaphoresis, and dangerous hyperthermia (>40°C or 104°F). Patients often exhibit inappropriate clothing removal due to hyperthermia. Sudden unresponsiveness following a period of intense physical struggle is a massive red flag for impending cardiac arrest.
Diagnosis
A purely clinical diagnosis requiring immediate recognition before laboratory confirmation. The first step is obtaining a rapid bedside capillary blood glucose to rule out hypoglycemia. Subsequent workup must include an ECG to check for QT prolongation or ischemic changes, and a creatine kinase (CK) level to assess for rhabdomyolysis. Basic metabolic panel and arterial blood gas are necessary to evaluate for severe metabolic acidosis and hyperkalemia.
Treatment
The primary goal is rapid, safe chemical sedation to halt the catecholamine surge and physical struggle. IM ketamine is the first-line agent due to its rapid onset (1-3 minutes) and preservation of airway reflexes. Alternatively, high-dose IM midazolam or IM haloperidol can be used. Physical restraints must be minimized or removed immediately after chemical sedation to prevent asphyxia and sudden cardiac death. Initiate rapid evaporative cooling for hyperthermia and aggressive IV fluid resuscitation for rhabdomyolysis.
Prognosis
Without rapid chemical sedation and cooling, mortality is exceptionally high due to cardiopulmonary arrest. Survivors are at significant risk for acute kidney injury secondary to myoglobinuria from severe rhabdomyolysis. Continuous cardiac and end-tidal CO2 monitoring is strictly required post-sedation.
Differential Diagnosis
1. Neuroleptic Malignant Syndrome (NMS): Features lead-pipe rigidity and bradyreflexia, triggered by dopamine antagonists rather than sympathomimetic overdose.
2. Serotonin Syndrome: Characterized by clonus and hyperreflexia, typically in a patient taking multiple serotonergic agents.
3. Hypoglycemia: Can present with severe agitation and diaphoresis, easily differentiated by a rapid capillary blood glucose <70 mg/dL.
4. Thyroid Storm: Presents with hyperthermia and tachycardia but usually features a history of hyperthyroidism and lacks the extreme combativeness or superhuman strength.