Heat stroke: Difference between revisions
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==Treatment== | ==Treatment== | ||
===General=== | ===General=== | ||
#Remove from environment | |||
#Address airway, breathing and circulation | |||
#IV normal saline | |||
#*Bolus if hypotensive | |||
#*Titrate to urine output, start at 250mL/hour | |||
#*Avoid aggressive IV fluid resuscitation unless severely dehydrated | |||
===Cooling=== | ===Cooling=== |
Revision as of 12:16, 26 August 2015
Background
- Universally fatal if left untreated
- Types
- Classic (nonexertional)
- Seen in children and elderly
- Exertional
- Seen in otherwise young, healthy individuals
- Classic (nonexertional)
Clinical Features
- Heat exposure + elevated temperature >40C (>104F) + neurologic abnormalities:
- Anhidrosis is frequently present; however, its absence does NOT rule out heat stroke
- Symptoms seen in Heat Exhaustion may also be present
Differential Diagnosis
Environmental
Environmental heat diagnoses
Non-Environmental
- Infectious
- Endocrine
- Neurologic
- Hypothalamic bleeding or infarct
- CVA
- Status epilepticus
- Toxicologic
- Anticholinergic toxidrome
- Sympathomimetic overdose
- Salicylate overdose
- Serotonin syndrome
- Malignant hyperthermia
- Neuroleptic Malignant Syndrome
- Withdrawal (ETOH, benzo)
Altered mental status and fever
- Infectious
- Sepsis
- Meningitis
- Encephalitis
- Cerebral malaria
- Brain abscess
- Other
Diagnosis
- Diagnosis is made by history and physical exam and exclusion of other diseases
- Blood glucose
- CBC
- Chemistry
- Arterial blood gas or Venous blood gas
- PaCO2 is often <20 2/2 hyperventilation
- Lactate
- Often elevated in exertional heat stroke
- Coagulation studies
- Creatine phosphokinase
- Urinanalysis
- ECG
- Chest x-ray
- CT brain and/orLP as needed
Treatment
General
- Remove from environment
- Address airway, breathing and circulation
- IV normal saline
- Bolus if hypotensive
- Titrate to urine output, start at 250mL/hour
- Avoid aggressive IV fluid resuscitation unless severely dehydrated
Cooling
- Mainstay of treatment
- Goal is to reduce temp to 39C (102.2F) and then stop to avoid overshoot hypothermia
- Antipyretics (ASA and acetaminophen) and dantrolene have no role
- Cooling blankets work too slowly to be employed as sole treatment
- Ice packs to neck, axillae, groin are useful as adjunct only
- Cold IVF is not effective
- Techniques
- Evaporative
- Method of choice
- Spray cool water (15C (59F)) on most of pt's body surface; turn on fan
- Complications
- Shivering (occurs when skin temp is <30C (86F): treat with short-acting benzodiazepines
- Electrodes not sticking: place on pt's back instead
- Ice-water immersion
- Consider especially in young, healthy pts
- Complications
- Shivering
- Inability to perform defibrillation or resuscitative procedures
- Invasive
- Consider if evaporative cooling or immersion is insufficient
- Cardiopulmonary bypass
- Cold water gastric, bladder or rectal lavage
- Evaporative
Complications
- Hypotension
- BP will usually respond to small fluid bolus (500cc) and body cooling
- If ineffective consider vasopressors (dopamine or dobutamine)
- Avoid peripheral vasoconstriction (norepinephrine)
- May redirect blood flow away from skin
- BP will usually respond to small fluid bolus (500cc) and body cooling
- Electrolyte abnormalities
- Variable: hypokalemia and hyper or hyponatremia may be seen
- Hematologic
- DIC or abnormal bleeding
- Hepatic injury
- Almost always reversible
- Renal failure
- ARDS
- Seizure
- Treat with Benzodiazepines
- Neurologic deficit
- Persistent in 20%, associated with high mortality
Disposition
- All patients require admission
See Also
References
Waters T. Heat Emergencies In: Tintinalli's Emergency Medicine: A Comprehensive Study Guide. 7th ed. McGraw Hill Medical. 2011: 1339