Heat stroke

Revision as of 13:50, 28 June 2015 by Rossdonaldson1 (talk | contribs) (Complications)

Background

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

Clinical Features

  • Heat exposure + elevated temperature >40C (>104F) + neurologic abnormalities:
    • Inappropriate behavior
    • Confusion
    • Delirium
    • Ataxia
    • Coma
    • Seizures
  • Anhidrosis is frequently present; however, its absence does NOT rule out heat stroke

Differential Diagnosis

Environmental

Environmental heat diagnoses

Non-Environmental

Altered mental status and fever

Diagnosis

  • Blood sugar
  • CBC
  • Chemistry
  • VBG
    • PaCO2 is often <20 2/2 hyperventiltaion
    • Exertional heat stroke often results in lactic acidosis
  • Coags
  • CK
  • UA
  • ECG
  • CXR
  • ?CT/LP

Treatment

General

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

Cooling

  • 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): tx w/ short-acting benzos
        • 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 / immersion is insufficient
      • Examples: cold water gastric lavage, bladder lavage, rectal lavage

Complications

  • Hypotension
    • BP will usually respond to small fluid bolus (500cc) and body cooling
      • If ineffective consider pressors (dopamine or dobutamine)
  • Electrolyte abnormalities
    • Variable: hypokalemia and hyper or hyponatremia may be seen
  • Hematologic
    • DIC or abnormal bleeding
  • Renal failure
  • ARDS
  • Seizure

See Also

References