What are the key treatments for heat stroke in the Emergency Department (ED)?

From the Guidelines

The most effective treatment for heat stroke in the emergency department is immediate full-body ice water immersion, which should be conducted before patient transport and continued until the body has cooled to a temperature below 38.9°C/102°F, as this method has been shown to have fatality rates close to zero if the body temperature is brought to less than 40.0°C within 30 min after collapse 1.

Key Considerations

• The primary goal is to rapidly lower body temperature to prevent irreversible organ damage, as heat stroke carries a high mortality rate even with prompt treatment.
• Core body temperature should be continuously monitored with rectal thermometry, as it is the most accurate method for measuring body temperature 1.
• Remove all clothing and apply active cooling measures, such as immersion in ice water, applying ice packs to the neck, axillae, and groin, using cooling blankets, or performing evaporative cooling with misting water and fans.
• Provide airway management as needed, including intubation for patients with altered mental status.
• Administer IV fluids (normal saline) to address hypotension and dehydration, but avoid overhydration.
• Treat seizures with benzodiazepines such as lorazepam 2-4 mg IV or diazepam 5-10 mg IV.
• Monitor for and correct electrolyte abnormalities, particularly hyponatremia, hyperkalemia, and hypocalcemia.
• Watch for complications including rhabdomyolysis, acute kidney injury, liver failure, DIC, and cardiac dysfunction.
• Avoid antipyretics like acetaminophen or NSAIDs as they are ineffective in heat stroke since the condition is not mediated by pyrogens.

Cooling Methods

• Full-body ice water immersion is the most effective immediate treatment of exertional heatstroke, with fatality rates close to zero if the body temperature is brought to less than 40.0°C within 30 min after collapse 1.
• Practical alternatives include applying ice packs to the neck, axillae, and groin; using cooling blankets; performing evaporative cooling with misting water and fans; or using cold IV fluids (4°C saline at 30 ml/kg).

Hemodynamic Management

• Acute circulatory failure is found in 20% to 65% of patients with heatstroke and has been implicated in the aggravation of tissue injury and cell death 1.
• The cause of this failure is not well understood but has been attributed variously to pooling of blood into the cutaneous circulation, volume loss by evaporation and insufficient intake of fluid, myocardial damage, and distributive shock resembling that of sepsis 1.

From the Research

Keys of Treatment of Heat Stroke in ED

• Rapid cooling is the most important feature in the treatment of heat stroke, as the prognosis is directly related to the degree of hyperthermia and its duration 2
• Immediate cooling and support of organ-system function are the two main therapeutic objectives in patients with heat stroke 3
• Cooling methods include:
  • Immersion in water at different temperatures (e.g. cold water, ice water) 4, 2
  • Evaporative cooling 3, 2, 5
  • Ice pack application 2
  • Pharmacological treatment 2
  • Invasive techniques 2
• Water immersion techniques (using 1-17°C water) can rapidly reduce core body temperature in settings where it is feasible 4
• Immersion in an ice-water bath is the most effective cooling method, and evaporative cooling is a rapid and effective alternative 3
• Aggressive IV rehydration should be continued for the first 24 to 72 hours to prevent the development of rhabdomyolysis-induced acute renal failure 3
• Treatment of heat cramps consists of fluid and salt replacement (PO or IV) and rest in a cool environment, with IV magnesium sulphate as an option for severe cases 3
• Cold water immersion therapy is the most efficient and efficacious modality in treating heat stroke, and can be initiated in the prehospital setting using a body bag 6