Heat stroke: Difference between revisions
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*Severe end of heat-related illness spectrum | *Severe end of heat-related illness spectrum | ||
*True emergency - universally fatal if left untreated | *True emergency - universally fatal if left untreated | ||
**Mortality approaches 30% even with treatment<ref name="Gaudio">Gaudio FG, Grissom CK. Cooling Methods in Heat Stroke. J Emerg Med. 2015 Oct 31.</ref> | |||
===Types=== | ===Types=== | ||
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==Diagnosis== | ==Diagnosis== | ||
===Workup=== | ===Workup=== | ||
*Core temperature (continuous monitoring is ideal, e.g. with bladder temperature monitor) | |||
*Blood glucose | *Blood glucose | ||
*CBC | *CBC | ||
* | *Metabolic panel | ||
* | *LFTs (AST>1000 indicates poor prognosis) | ||
*Blood gas | |||
* | *[[Lactate]] | ||
*[[Lactate]] | |||
*Coagulation studies | *Coagulation studies | ||
*Creatine phosphokinase and myoglobin | *Creatine phosphokinase and myoglobin | ||
* | *Urinalysis | ||
*[[ECG]] | *[[ECG]] | ||
*Chest x-ray | *Chest x-ray | ||
*CT brain | *CT brain (± LP), if indicated | ||
===Evaluation=== | ===Evaluation=== | ||
* | *Clinical diagnosis | ||
==Management== | ==Management== | ||
*Address ABCs | *Address ABCs | ||
*Rapid cooling (see below) - mainstay of treatment | *Rapid cooling (see below) - mainstay of treatment | ||
**Reduces morbidity, should be started in prehospital setting if no other life-threats exist<ref name="Becker" /> | **Reduces morbidity/mortality, should be started in prehospital setting if no other life-threats exist<ref name="Becker" /> | ||
*Remove from environment | *Remove from environment | ||
*IVF (for renal protection and avoiding rhabdomyolysis) | *IVF (for renal protection and avoiding rhabdomyolysis) | ||
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===Rapid Cooling=== | ===Rapid Cooling=== | ||
*Goal is to reduce temp to | *Goal is to reduce temp to 39°C (102.2°F) - take care to avoid overshoot hypothermia | ||
*Antipyretics (ASA and acetaminophen) and dantrolene have no role | *Antipyretics (ASA and acetaminophen) and dantrolene have no role | ||
*Cooling blankets work too slowly to be employed as sole treatment | *Cooling blankets work too slowly to be employed as sole treatment |
Revision as of 05:28, 6 March 2016
Background
- Severe end of heat-related illness spectrum
- True emergency - universally fatal if left untreated
- Mortality approaches 30% even with treatment[1]
Types
- Classic (nonexertional) - insidious development over days
- Seen in children and elderly
- Exertional - rapid onset during exercise or other exertion
- Seen in otherwise young, healthy individuals
Clinical Features
- Symptoms[2]
- Anhidrosis is frequently present; however, its absence does NOT rule out heat stroke
Differential Diagnosis
Environmental heat diagnoses
Non-Environmental
- Infectious
- Endocrine
- Neurologic
- Hypothalamic bleeding or infarct
- CVA
- Status epilepticus
- Toxicologic
- Anticholinergic toxidrome
- Sympathomimetic toxicity
- Aspirin (Salicylate) toxicity
- Serotonin syndrome
- Malignant hyperthermia
- Neuroleptic malignant syndrome
- Withdrawal (e.g. ETOH, Benzodiazepines)
Altered mental status and fever
- Infectious
- Sepsis
- Meningitis
- Encephalitis
- Cerebral malaria
- Brain abscess
- Other
Diagnosis
Workup
- Core temperature (continuous monitoring is ideal, e.g. with bladder temperature monitor)
- Blood glucose
- CBC
- Metabolic panel
- LFTs (AST>1000 indicates poor prognosis)
- Blood gas
- Lactate
- Coagulation studies
- Creatine phosphokinase and myoglobin
- Urinalysis
- ECG
- Chest x-ray
- CT brain (± LP), if indicated
Evaluation
- Clinical diagnosis
Management
- Address ABCs
- Rapid cooling (see below) - mainstay of treatment
- Reduces morbidity/mortality, should be started in prehospital setting if no other life-threats exist[2]
- Remove from environment
- IVF (for renal protection and avoiding rhabdomyolysis)
- Bolus if hypotensive
- Infusion titrated to UOP (goal 250mL/hour)
Rapid Cooling
- Goal is to reduce temp to 39°C (102.2°F) - take care 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