Emergency Medicine · Year 3 · from Emergency Medicine
Case 3: Sympathomimetic Toxidrome - Methamphetamine Intoxication
Patient Demographics
- Age: 32 years
- Sex: Male
- Occupation: Unknown
Chief Complaint
"He's acting crazy and won't calm down."
History of Present Illness
Police bring a 32-year-old male to the ED for altered mental status and combative behavior. Found at a convenience store throwing items and threatening customers. He is agitated, paranoid, and appears to be responding to internal stimuli. Bystanders report patient was "smoking something" outside the store. He is known to police for prior methamphetamine-related arrests.
Initial Assessment
ESI Level: 1 - Immediate intervention for safety and medical stabilization
First Impression:
- Appearance: Extremely agitated, diaphoretic, pupils dilated
- Work of breathing: Tachypneic
- Circulation: Flushed, diaphoretic
Vital Signs (obtained with difficulty):
- Heart rate: 142 bpm
- Blood pressure: 198/112 mmHg
- Respiratory rate: 28 breaths/min
- SpO2: 96% on room air
- Temperature: 39.4C (102.9F) - HYPERTHERMIA
- GCS: 14 (E4V4M6 - confused)
Sympathomimetic Toxidrome
| Finding | Present |
|---|---|
| Agitation/psychosis | Yes - severe |
| Tachycardia | Yes - HR 142 |
| Hypertension | Yes - 198/112 |
| Hyperthermia | Yes - 39.4C |
| Diaphoresis | Yes |
| Mydriasis (dilated pupils) | Yes - 7mm |
| Tremor | Yes |
Immediate Safety and Stabilization
Agitation Management:
- Verbal de-escalation attempted - unsuccessful
- Security and police assistance for safety
- Chemical restraint:
- Midazolam 5mg IM (unable to obtain IV initially)
- Repeated midazolam 5mg IV after access obtained
- Physical restraints for safety (removed once sedation effective)
Critical Point: Benzodiazepines are first-line for sympathomimetic toxicity - treat agitation, hypertension, tachycardia, and hyperthermia simultaneously
Primary Survey (After Sedation)
Airway: Patent, maintaining own airway Breathing: Tachypneic but adequate Circulation: Tachycardic, hypertensive, warm and flushed Disability: Sedated but arousable, GCS 13 Exposure: No trauma, no injection sites, dental caries (meth mouth)
Hyperthermia Management
Temperature 39.4C - requires active cooling:
- Remove clothing
- Ice packs to axillae, groin, neck
- Evaporative cooling (mist and fan)
- Cold IV fluids
- Target temperature <38.5C
- Avoid shivering (counterproductive; additional benzos if needed)
Avoid antipyretics: Hyperthermia is not due to pyrogens; acetaminophen/ibuprofen ineffective
Secondary Survey
SAMPLE History (limited):
- Symptoms: Agitation, paranoia, hallucinations
- Allergies: Unknown
- Medications: Unknown
- PMH: Per police - prior meth use, psychiatric history
- Last Meal: Unknown
- Events: Witnessed smoking substance
Physical Examination:
- Head: Atraumatic, pupils 7mm and reactive
- Mouth: Severe dental decay, dry mucous membranes
- Neck: Supple, no meningismus
- Cardiac: Tachycardic, regular, no murmurs
- Lungs: Clear, tachypneic
- Abdomen: Soft, non-tender
- Skin: Diaphoretic, no injection marks, multiple excoriations (picking)
- Neuro: Agitated, moving all extremities, no focal deficits
Diagnostic Testing
Labs:
- WBC: 14,200
- BMP: Na 138, K 3.2, Cl 102, HCO3 18, BUN 24, Cr 1.4
- Glucose: 168
- CPK: 4,850 IU/L (elevated - rhabdomyolysis)
- Troponin: 0.08 ng/mL (mildly elevated)
- Lactate: 4.2 mmol/L
- Urine drug screen: Positive for amphetamines
- Urinalysis: Brown urine, positive blood (myoglobinuria)
ECG:
- Sinus tachycardia at 138 bpm
- No ischemic changes
- QTc 440ms (normal)
CT Head (given altered mental status): No acute intracranial abnormality
Diagnosis
Acute methamphetamine intoxication with:
- Sympathomimetic toxidrome
- Hyperthermia
- Rhabdomyolysis
- Acute kidney injury
Management
Continued Treatment:
- Benzodiazepines: Total midazolam 20mg over first 2 hours for adequate sedation
- Rhabdomyolysis Prevention/Treatment:
- Aggressive IV fluids: LR at 200-300 mL/hour
- Goal UOP >200-300 mL/hour
- Serial CPK monitoring (peak expected 24-72 hours)
- Monitor potassium, calcium, phosphorus
- Hypertension Management:
- Primarily with benzodiazepines
- If refractory: Nicardipine or phentolamine
- AVOID beta-blockers (unopposed alpha stimulation)
- Hyperthermia:
- Active cooling continued
- Temperature normalized to 37.8C within 2 hours
- Supportive Care:
- Cardiac monitoring
- Electrolyte repletion (K+)
- NPO until mental status clear
Clinical Course
At 6 hours:
- Temperature: 37.4C
- HR: 102 bpm
- BP: 148/88 mmHg
- Mental status improving
- CPK: 8,200 (rising, expected)
- Creatinine: 1.6 (worsening)
At 24 hours:
- Calm, cooperative
- CPK: 12,400 (peak)
- Creatinine: 1.4 (improving with fluids)
- UOP >150 mL/hour
Disposition
- Medical admission for rhabdomyolysis management
- Continued IV fluids
- Psychiatry consultation
- Addiction services consultation
- Social work involvement
- Discharged on day 3 with CPK trending down, creatinine normalized
- Outpatient addiction treatment arranged
Teaching Points
- Benzodiazepines are cornerstone: Treat agitation, hyperthermia, hypertension, and tachycardia simultaneously
- Avoid antipsychotics initially: May lower seizure threshold, worsen hyperthermia
- Avoid beta-blockers: Risk of unopposed alpha stimulation and worsening hypertension
- Hyperthermia kills: Active cooling essential; not responsive to antipyretics
- Rhabdomyolysis common: Check CPK, aggressive hydration, monitor for AKI and hyperkalemia
- Medical clearance before psychiatric: Ensure no life-threatening toxicity before transfer
- Excited delirium: Severe agitation with hyperthermia carries risk of sudden death; aggressive treatment needed
Clinical Image
Image Description: Photograph showing bilateral mydriasis (dilated pupils) measuring approximately 7mm, characteristic of sympathomimetic toxicity. The pupils are symmetrically dilated but remain reactive to light.
Attribution: Image from Wikimedia Commons, Mydriasis. Licensed under CC BY-SA 4.0. Source: https://commons.wikimedia.org/wiki/File:Mydriasis.jpg