High altitude cerebral edema: Difference between revisions
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==Background== | ==Background== | ||
*Also known as HACE | *Also known as HACE | ||
*Progressive neurologic deterioration in someone with | *Progressive neurologic deterioration in someone with [[acute mountain sickness]] or [[HAPE]] (due to ↑ ICP) | ||
*Almost never occurs at < | *Almost never occurs at <8,000ft | ||
==Clinical Features== | ==Clinical Features== | ||
*Altered mental status, ataxia, gait disturbance, stupor (most sensitive findings) | *[[Altered mental status]], [[ataxia]], gait disturbance, stupor (most sensitive findings) | ||
**Progresses to coma if untreated | **Progresses to [[coma]] if untreated | ||
*Headache, nausea | *Uncertain mechanism, presumed cause is hypoxia leading to cerebral edema | ||
*Focal neuro deficits may be seen (3rd/6th CN palsies) | *[[Headache]], [[nausea/vomiting]] (not always present) | ||
*Seizures are rare | *[[Focal neuro deficits]] may be seen ([[CN III palsy|3rd]]/[[abducens nerve palsy|6th]] CN palsies) | ||
*[[Seizures]] are rare | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
{{High altitude DDX}} | {{High altitude DDX}} | ||
*Dehydration | *[[Dehydration]] | ||
*Exhaustion | *Exhaustion | ||
*Hypoglycemia | *[[Hypoglycemia]] | ||
*Hypothermia | *[[Hypothermia]] | ||
*Hyponatremia | *[[Hyponatremia]] | ||
== | ==Evaluation== | ||
* | [[File:PMC3775198 LI-30-193-g007.png|thumb|Head CT of HACE showing diffuse effacement of cerebral sulci and compression of ventricles.]] | ||
*Typically a clinical diagnosis | |||
{{Expected SpO2 at altitude}} | |||
==Management== | ==Management== | ||
[[File:Altitude flow sheet.png|thumb|High altitude management algorithm.]] | |||
*Immediate descent is the treatment of choice | *Immediate descent is the treatment of choice | ||
*If descent not possible use combination of: | *If descent not possible use combination of: | ||
**Supplemental O2 (goal SpO2 90%)<ref>Hackett PH, Roach RC. High altitude cerebral edema. High Alt Med Biol 2004; 5:136-146.</ref> | **Supplemental [[O2]] (goal SpO2 90%)<ref>Hackett PH, Roach RC. High altitude cerebral edema. High Alt Med Biol 2004; 5:136-146.</ref> | ||
**Dexamethasone 8mg initially, then 4mg q6hr | **Supportive hyperventilation | ||
**Acetazolamide | **[[Dexamethasone]] 8mg initially (PO, IM, or IV), then 4mg q6hr | ||
**Hyperbaric bag if available | **[[Acetazolamide]] 250mg BID (better as ppx) | ||
**Hyperbaric bag (Gamow bag) if available | |||
==Prevention== | ==Prevention== | ||
*Acetazolamide 125mg BID (250mg BID if greater than 100kg) | *Acclimatization, slow ascent | ||
*Dexamethasone 4mg q6h PO or IV | *[[Acetazolamide]] 125mg BID (250mg BID if greater than 100kg) | ||
*[[Dexamethasone]] 4mg q6h PO or IV | |||
==See Also== | ==See Also== | ||
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<references/> | <references/> | ||
[[Category: | [[Category:Environmental]] |
Revision as of 19:27, 2 March 2020
Background
- Also known as HACE
- Progressive neurologic deterioration in someone with acute mountain sickness or HAPE (due to ↑ ICP)
- Almost never occurs at <8,000ft
Clinical Features
- Altered mental status, ataxia, gait disturbance, stupor (most sensitive findings)
- Progresses to coma if untreated
- Uncertain mechanism, presumed cause is hypoxia leading to cerebral edema
- Headache, nausea/vomiting (not always present)
- Focal neuro deficits may be seen (3rd/6th CN palsies)
- Seizures are rare
Differential Diagnosis
High Altitude Illnesses
- Acute mountain sickness
- Chronic mountain sickness
- High altitude cerebral edema
- High altitude pulmonary edema
- High altitude peripheral edema
- High altitude retinopathy
- High altitude pharyngitis and bronchitis
- Ultraviolet keratitis
- Dehydration
- Exhaustion
- Hypoglycemia
- Hypothermia
- Hyponatremia
Evaluation
- Typically a clinical diagnosis
Expected SpO2 and PaO2 levels at altitude[1]
Altitude | SpO2 | PaO2 (mm Hg) |
---|---|---|
1,500 to 3,500 m (4,900 to 11,500 ft) | about 90% | 55-75 |
3,500 to 5,500 m (11,500 to 18,000 ft) | 75-85% | 40-60 |
5,500 to 8,850 m (18,000 to 29,000 ft) | 58-75% | 28-40 |
Management
- Immediate descent is the treatment of choice
- If descent not possible use combination of:
- Supplemental O2 (goal SpO2 90%)[2]
- Supportive hyperventilation
- Dexamethasone 8mg initially (PO, IM, or IV), then 4mg q6hr
- Acetazolamide 250mg BID (better as ppx)
- Hyperbaric bag (Gamow bag) if available
Prevention
- Acclimatization, slow ascent
- Acetazolamide 125mg BID (250mg BID if greater than 100kg)
- Dexamethasone 4mg q6h PO or IV