Heatstroke and Heat Injury

First Things First (assess & treat for the following)

• For malignant hyperthermia, emergently administer dantrolene sodium 2 mg/kg IV, repeated q5min, up to 10 mg/kg total dose.
• Definitions
  • Exertional heatstroke: seen in relatively healthy individuals who overexert themselves during times of high ambient temperature and humidity (endogenous heat generation exceeds heat dissipation)
  • Non-exertional heatstroke: seen in elderly or ill individuals w/ impaired thermoregulation during times of higher-than-normal ambient temperatures
  • Iatrogenic: drug-induced neuroleptic malignant syndrome (NMS) or malignant hyperthermia (MH)
  • Acclimatization: the physiologic process of adaptation over time to work in a hot environment (increased sweat production, decreased sweat sodium concentration, increased aldosterone secretion, increased cardiac output, decreased heart rate)
• Morbidity & mortality are most directly determined by the duration of hyperpyrexia, followed by the extent of temp elevation.
  • Rapid identification & treatment of heatstroke is crucial to survival.
  • In elderly & ill, central thermoregulation is commonly impaired & the diagnosis can be overlooked or mistaken for other etiologies.
• Dehydration is not a universal finding, especially in non-exertional heatstroke victims; IV fluid resuscitation must be individualized according to pt volume status.
• Cooling can be adequately accomplished by placing pt in an air-conditioned room, applying ice packs, giving tepid water sponge baths & directing fans across the pt.
• Don’t forget the ABCs! Pts are often obtunded. Ensure airway protection to prevent aspiration as well as ventilation & oxygenation.
• In an urban setting, cocaine intoxication is one of the most common causes of heatstroke.