Heat stroke

Revision as of 15:52, 10 June 2015 by Rossdonaldson1 (talk | contribs) (Differential Diagnosis)


  1. Universally fatal if left untreated
  2. Types
    1. Classic (nonexertional)
      1. Seen in children and elderly
    2. Exertional
      1. Seen in otherwise young, healthy individuals


  1. Heat exposure + elevated temperature >40C (>104F) + neurologic abnormalities:
    1. Inappropriate behavior
    2. Confusion
    3. Delirium
    4. Ataxia
    5. Coma
    6. Seizures
  2. Anhidrosis is frequently present; however, its absence does NOT rule out heat stroke
    1. Symptoms seen in Heat Exhaustion may also be present

Differential Diagnosis


Environmental heat diagnoses


Altered mental status and fever


  1. Blood sugar
  2. CBC
  3. Chemistry
  4. VBG
    1. PaCO2 is often <20 2/2 hyperventiltaion
    2. Exertional heat stroke often results in lactic acidosis
  5. Coags
  6. CK
  7. UA
  8. ECG
  9. CXR
  10. ?CT/LP



  1. IVF
    1. Initiate at a rate that ensures adequate (start w/ NS 250cc/hr)


  1. Goal is to reduce temp to 39C (102.2F) and then stop to avoid overshoot hypothermia
  2. Antipyretics (ASA and acetaminophen) and dantrolene have no role
  3. Cooling blankets work too slowly to be employed as sole treatment
  4. Ice packs to neck, axillae, groin are useful as adjunct only
  5. Cold IVF is not effective
  6. Techniques
    1. Evaporative
      1. Method of choice
      2. Spray cool water (15C (59F)) on most of pt's body surface; turn on fan
      3. Complications
        1. Shivering (occurs when skin temp is <30C (86F): tx w/ short-acting benzos
        2. Electrodes not sticking: place on pt's back instead
    2. Ice-water immersion
      1. Consider especially in young, healthy pts
      2. Complications
        1. Shivering
        2. Inability to perform defibrillation or resuscitative procedures
    3. Invasive
      1. Consider if evaporative cooling / immersion is insufficient
      2. Examples: cold water gastric lavage, bladder lavage, rectal lavage


  1. Hypotension
    1. BP will usually respond to small fluid bolus (500cc) and body cooling
      1. If ineffective consider pressors (dopamine or dobutamine)
  2. Electrolyte abnormalities
    1. Variable: hypokalemia and hyper or hyponatremia may be seen
  3. Hematologic
    1. DIC or abnormal bleeding
  4. Renal failure
  5. ARDS
  6. Seizure
    1. Tx w/ benzos

See Also