Heat stroke: Difference between revisions
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==Background== | ==Background== | ||
* | *Severe end of heat-related illness spectrum | ||
*True emergency - universally fatal if left untreated | |||
===Types=== | ===Types=== | ||
*Classic (nonexertional) | *Classic (nonexertional) - insidious development over days | ||
**Seen in children and elderly | **Seen in children and elderly | ||
*Exertional | *Exertional - rapid onset during exercise or other exertion | ||
**Seen in otherwise young, healthy individuals | **Seen in otherwise young, healthy individuals | ||
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**[[Coma]] | **[[Coma]] | ||
**[[Seizures]] | **[[Seizures]] | ||
*Anhidrosis is frequently present; however, its absence does NOT rule out heat stroke | *Anhidrosis is frequently present; however, its absence does '''NOT''' rule out heat stroke | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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*Diagnosis is made by history and physical exam and exclusion of other diseases | *Diagnosis is made by history and physical exam and exclusion of other diseases | ||
== | ==Management== | ||
===General=== | ===General=== | ||
#Remove from environment | #Remove from environment | ||
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==References== | ==References== | ||
<references/> | |||
[[Category:Environ]] | [[Category:Environ]] |
Revision as of 03:11, 6 March 2016
Background
- Severe end of heat-related illness spectrum
- True emergency - universally fatal if left untreated
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
- Heat exposure + elevated temperature >40C (>104F) + neurologic abnormalities:
- 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 overdose
- Salicylate overdose
- Serotonin syndrome
- Malignant hyperthermia
- Neuroleptic Malignant Syndrome
- Withdrawal (ETOH, benzo)
Altered mental status and fever
- Infectious
- Sepsis
- Meningitis
- Encephalitis
- Cerebral malaria
- Brain abscess
- Other
Diagnosis
Workup
- Blood glucose
- CBC
- Chemistry
- Elevated LFTs sensitive for heat stroke
- AST > 1000, poor prognosis
- Especially in exertional heat stroke
- Arterial blood gas or Venous blood gas
- PaCO2 is often <20 2/2 hyperventilation
- Lactate (often elevated in exertional heat stroke)
- Coagulation studies
- Creatine phosphokinase and myoglobin
- Urine analysis
- ECG
- Chest x-ray
- CT brain and/orLP as needed
Evaluation
- Diagnosis is made by history and physical exam and exclusion of other diseases
Management
General
- Remove from environment
- Address airway, breathing and circulation
- IV normal saline
- Bolus if hypotensive
- Titrate to urine output, start at 250mL/hour
- Avoid aggressive IV fluid resuscitation unless severely dehydrated
Cooling
- Mainstay of treatment
- 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): 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