Heat stroke: Difference between revisions
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==Background== | ==Background== | ||
*Severe end of heat-related illness spectrum characterized by severe hyperthermia and neurologic dysfunction | |||
*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>, and is directly associated with the duration of elevated core temperature | |||
*Hallmark is multisystem organ dysfunction from heat-induced damage resulting in systemic inflammatory response | |||
== | ===Types=== | ||
*Classic (nonexertional) - insidious development over days | |||
**Seen in children and elderly | |||
**During the time of [[heat wave]] | |||
*Exertional - rapid onset during exercise or other exertion | |||
**Seen in otherwise young, healthy individuals | |||
== | ==Clinical Features== | ||
*Symptoms<ref name="Becker">Becker JA, Stewart LK. Heat-related illness. Am Fam Physician. 2011 Jun 1;83(11):1325-30.</ref> | |||
**Elevated temperature >40°C (104°F) '''PLUS''' | |||
**CNS neurologic abnormalities (e.g. inappropriate behavior, [[Confusion]], [[dysarthria|slurred speech]], [[Delirium]], [[Ataxia]], [[Coma]], [[Seizures]]) | |||
*Anhidrosis is frequently present; however, its absence does NOT rule out heat stroke | |||
*May have massive [[rectal bleeding|hematochezia]] secondary to decreased intestinal perfusion and ischemia<ref>Lambert GP. Intestinal barrier dysfunction, endotoxemia, and gastrointestinal symptoms: the 'canary in the coal mine' during exercise-heat stress? Med Sport Sci. 2008;53:61-73.</ref> | |||
== | ==Differential Diagnosis== | ||
{{Template:Heat Emergencies}} | |||
== | ===Non-Environmental=== | ||
*Infectious | |||
**[[Sepsis (Main)|Sepsis]] | |||
**[[Meningitis]] | |||
**[[Encephalitis]] | |||
**[[Malaria]] | |||
**[[Typhoid]] | |||
**[[Tetanus]] | |||
*Endocrine | |||
**[[Thyroid storm]] | |||
**[[Pheochromocytoma]] | |||
**[[Diabetic ketoacidosis|DKA]] | |||
*Neurologic | |||
**Hypothalamic [[ICH|bleeding]] or [[stroke|infarct]] | |||
**[[Stroke (main)|CVA]] | |||
**[[Status epilepticus]] | |||
*Toxicologic | |||
**[[Anticholinergic toxicity|Anticholinergic toxidrome]] | |||
**[[Sympathomimetic toxicity]] | |||
**[[Salicylate toxicity]] | |||
**[[Serotonin syndrome]] | |||
**[[Malignant hyperthermia]] | |||
**[[Neuroleptic malignant syndrome]] | |||
**Withdrawal (e.g. [[ETOH withdrawal|ETOH]], [[benzodiazepine withdrawal|benzodiazepines]]) | |||
=== | {{AMS and fever DDX}} | ||
==Evaluation== | |||
===Workup=== | |||
*[[ECG]]<ref>Mimish L. Electrocardiographic findings in heat stroke and exhaustion: A study on Makkah pilgrims. J Saudi Heart Assoc. 2012 Jan; 24(1): 35–39.</ref> | |||
**Most often sinus tachycardia, self-limited | |||
**Less frequently ischemic changes including ST depressions, TWIs | |||
*Core temperature (continuous monitoring is ideal, e.g. with bladder temperature monitor) | |||
*Blood glucose | |||
*CBC | |||
*Metabolic panel | |||
*[[LFTs]] | |||
*Blood gas | |||
*[[Lactate]] | |||
*Coagulation studies ([[DIC (Disseminated Intravascular Coagulation)|DIC]]) | |||
*Creatine phosphokinase and myoglobin ([[Rhabdomyolysis]]) | |||
*[[Urinalysis]] | |||
*[[CXR]] | |||
*[[CT brain]] (± [[LP]]), if indicated (Cerebral Edema) | |||
===Evaluation=== | |||
*Clinical diagnosis | |||
*Exposure to hot environment and high index of suspicion. | |||
==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<ref name="Becker" /> | |||
*Remove from environment | |||
*[[IVF]] (for renal protection and avoiding rhabdomyolysis) | |||
**Bolus if hypotensive | |||
**Infusion titrated to UOP (goal 2-3ml/kg/hr) | |||
===Rapid Cooling=== | |||
*Cooling end point should be ~39°C (102.2°F) - no good data for this goal<ref name="Gaudio" /> | |||
*No role for: antipyretics or dantrolene | |||
*Combination of methods, or adjuncts such as cool IVF may increase efficacy of individual methods | |||
====Techniques==== | |||
*Cool water immersion - treatment of choice<ref name="Becker" /><ref name="Pryor" /> | |||
**Immersion of body to level of torso or neck in cool or ice-water | |||
**Best for exertional heat stroke in young/healthy patients, but benefit shown in elderly patients as well | |||
**Diffuse application of ice or cold packs to entire body may provide similar benefit (but less data) | |||
***Applying ice packs only to neck, axillae, groin provides only minimal cooling<ref name="Gaudio" /> | |||
**Benefits: most rapid decrease in temperature, some studies have shown 100% survival (esp when started within 30 minutes of collapse)<ref name="Gaudio" /><ref name="Becker" /><ref name="Pryor">Pryor RR, Roth RN, Suyama J, Hostler D. Exertional heat illness: emerging concepts and advances in prehospital care. Prehosp Disaster Med. 2015 Jun;30(3):297-305.</ref> | |||
**Disadvantages: requires special equipment (may not be immediately available), poorly tolerated, unable to provide defibrillation or many other resuscitative measures | |||
*Evaporative/Convective Cooling | |||
**Spray cool water (15°C / 59°F) on patient while directing fans at patient | |||
**Benefits: Easier to apply in ED and while performing other interventions | |||
**Disadvantages: Slower cooling (than immersion) with slightly higher morbidity/mortality | |||
*Invasive Techniques (limited data <ref name="Gaudio" />) | |||
**Bladder Lavage | |||
**Gastric Lavage | |||
**Thoracic Lavage with chest tubes | |||
**Cardiopulmonary bypass/ECMO | |||
==Complications== | ==Complications== | ||
*[[Hypotension]] | |||
**Usually responds to small fluid bolus (500cc) and body cooling | |||
**If no response to fluids → consider [[vasopressors]] (dopamine or dobutamine) | |||
***Avoid peripheral vasoconstriction (e.g. norepinephrine), which may redirect blood flow away from skin and diminish cooling | |||
*[[Electrolyte abnormalities]] | |||
**Variable: [[hypokalemia]] and [[hypernatremia|hyper]] or [[hyponatremia]] may be seen | |||
*Hematologic - [[DIC]] or abnormal bleeding | |||
*[[hepatic failure|Hepatic injury]] - almost always reversible | |||
*[[Renal failure]] | |||
*[[ARDS]] | |||
*[[Seizure]] - treat with [[Benzodiazepines]] | |||
*[[focal neuro deficits|Neurologic deficit]] | |||
**Persistent in 20%, associated with high mortality | |||
==Disposition== | |||
*All patients require admission | |||
==See Also== | ==See Also== | ||
[[Heat | *[[Heat emergencies]] | ||
*[[Heat exhaustion]] | |||
*[[Acute fever]] | |||
== | ==References== | ||
<references/> | |||
[[Category: | [[Category:Environmental]] |
Latest revision as of 17:01, 5 May 2022
Background
- Severe end of heat-related illness spectrum characterized by severe hyperthermia and neurologic dysfunction
- True emergency - universally fatal if left untreated
- Mortality approaches 30% even with treatment[1], and is directly associated with the duration of elevated core temperature
- Hallmark is multisystem organ dysfunction from heat-induced damage resulting in systemic inflammatory response
Types
- Classic (nonexertional) - insidious development over days
- Seen in children and elderly
- During the time of heat wave
- 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
- May have massive hematochezia secondary to decreased intestinal perfusion and ischemia[3]
Differential Diagnosis
Environmental heat diagnoses
Non-Environmental
- Infectious
- Endocrine
- Neurologic
- Hypothalamic bleeding or infarct
- CVA
- Status epilepticus
- Toxicologic
Altered mental status and fever
- Infectious
- Sepsis
- Meningitis
- Encephalitis
- Cerebral malaria
- Brain abscess
- Other
Evaluation
Workup
- ECG[4]
- Most often sinus tachycardia, self-limited
- Less frequently ischemic changes including ST depressions, TWIs
- Core temperature (continuous monitoring is ideal, e.g. with bladder temperature monitor)
- Blood glucose
- CBC
- Metabolic panel
- LFTs
- Blood gas
- Lactate
- Coagulation studies (DIC)
- Creatine phosphokinase and myoglobin (Rhabdomyolysis)
- Urinalysis
- CXR
- CT brain (± LP), if indicated (Cerebral Edema)
Evaluation
- Clinical diagnosis
- Exposure to hot environment and high index of suspicion.
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 2-3ml/kg/hr)
Rapid Cooling
- Cooling end point should be ~39°C (102.2°F) - no good data for this goal[1]
- No role for: antipyretics or dantrolene
- Combination of methods, or adjuncts such as cool IVF may increase efficacy of individual methods
Techniques
- Cool water immersion - treatment of choice[2][5]
- Immersion of body to level of torso or neck in cool or ice-water
- Best for exertional heat stroke in young/healthy patients, but benefit shown in elderly patients as well
- Diffuse application of ice or cold packs to entire body may provide similar benefit (but less data)
- Applying ice packs only to neck, axillae, groin provides only minimal cooling[1]
- Benefits: most rapid decrease in temperature, some studies have shown 100% survival (esp when started within 30 minutes of collapse)[1][2][5]
- Disadvantages: requires special equipment (may not be immediately available), poorly tolerated, unable to provide defibrillation or many other resuscitative measures
- Evaporative/Convective Cooling
- Spray cool water (15°C / 59°F) on patient while directing fans at patient
- Benefits: Easier to apply in ED and while performing other interventions
- Disadvantages: Slower cooling (than immersion) with slightly higher morbidity/mortality
- Invasive Techniques (limited data [1])
- Bladder Lavage
- Gastric Lavage
- Thoracic Lavage with chest tubes
- Cardiopulmonary bypass/ECMO
Complications
- Hypotension
- Usually responds to small fluid bolus (500cc) and body cooling
- If no response to fluids → consider vasopressors (dopamine or dobutamine)
- Avoid peripheral vasoconstriction (e.g. norepinephrine), which may redirect blood flow away from skin and diminish 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
See Also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Gaudio FG, Grissom CK. Cooling Methods in Heat Stroke. J Emerg Med. 2015 Oct 31.
- ↑ 2.0 2.1 2.2 2.3 Becker JA, Stewart LK. Heat-related illness. Am Fam Physician. 2011 Jun 1;83(11):1325-30.
- ↑ Lambert GP. Intestinal barrier dysfunction, endotoxemia, and gastrointestinal symptoms: the 'canary in the coal mine' during exercise-heat stress? Med Sport Sci. 2008;53:61-73.
- ↑ Mimish L. Electrocardiographic findings in heat stroke and exhaustion: A study on Makkah pilgrims. J Saudi Heart Assoc. 2012 Jan; 24(1): 35–39.
- ↑ 5.0 5.1 Pryor RR, Roth RN, Suyama J, Hostler D. Exertional heat illness: emerging concepts and advances in prehospital care. Prehosp Disaster Med. 2015 Jun;30(3):297-305.