Difference between revisions of "Heat stroke"
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==Background== | ==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 | |
| − | + | **Symptoms seen in [[Heat Exhaustion]] may also be present | |
==Differential Diagnosis== | ==Differential Diagnosis== | ||
| Line 49: | Line 49: | ||
{{AMS and fever DDX}} | {{AMS and fever DDX}} | ||
| − | == | + | ==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== | ==Treatment== | ||
===General=== | ===General=== | ||
| − | + | *IVF | |
| − | + | **Initiate at a rate that ensures adequate (start w/ NS 250cc/hr) | |
===Cooling=== | ===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== | ==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]] | |
| − | + | **Treate with benzos | |
==See Also== | ==See Also== | ||
| Line 108: | Line 108: | ||
*[[Acute Fever (DDX)]] | *[[Acute Fever (DDX)]] | ||
| − | == | + | ==References== |
| − | |||
[[Category:Environ]] | [[Category:Environ]] | ||
Revision as of 13:49, 28 June 2015
Contents
Background
- Universally fatal if left untreated
- Types
- Classic (nonexertional)
- Seen in children and elderly
- Exertional
- Seen in otherwise young, healthy individuals
- Classic (nonexertional)
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
- Symptoms seen in Heat Exhaustion may also be present
Differential Diagnosis
Environmental
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
- 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
- Evaporative
Complications
- Hypotension
- BP will usually respond to small fluid bolus (500cc) and body cooling
- If ineffective consider pressors (dopamine or dobutamine)
- 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
- Renal failure
- ARDS
- Seizure
- Treate with benzos