High-Altitude Cerebral Edema (HACE) Management
Immediate descent to lower altitude is the definitive, life-saving treatment for HACE and must be initiated at the earliest indication of cerebral edema, as this condition carries a 50% mortality rate when left untreated. 1
Immediate Actions
Descend immediately – This is the single most critical intervention and should not be delayed. 2, 3 Patients who were returned to low altitude early in the disease fared well, while delayed evacuation resulted in death. 2
Administer supplemental oxygen – Begin oxygen therapy immediately if available. 4, 3, 5
Give dexamethasone – Administer dexamethasone 10 mg intravenously initially, followed by 4 mg every 6 hours intramuscularly until symptoms of cerebral edema subside. 6 Response is usually noted within 12-24 hours. 6 Large doses of intravenous dexamethasone or betamethasone are recommended for rapid treatment. 2
Alternative Interventions When Descent is Impossible
If actual descent is not possible:
- Portable hyperbaric chamber – Use simulated descent in a portable hyperbaric chamber (Gamow bag) if oxygen is not available and actual descent cannot be achieved. 3
- Continue dexamethasone – Maintain high-dose dexamethasone therapy as described above. 4, 2
Adjunctive Medical Management
Supportive measures include:
- Hydration and diuresis – Administer intravenous fluids with furosemide for diuresis. 2
- Hyperosmolar therapy – Consider intravenous mannitol, urea, 50% saline, or 50% sucrose for cerebral edema management. 2
- Head elevation – Elevate the head of bed 20-30 degrees to facilitate venous drainage and reduce intracranial pressure. 7, 8
- Maintain normothermia – Ensure the patient remains normothermic as hyperthermia worsens cerebral edema. 7, 8
Clinical Monitoring
Watch for key symptoms:
- Decreased level of consciousness is the most reliable clinical indicator of tissue swelling. 7
- Severe headache, vomiting, and ataxia are hallmark features. 3
- Visual disturbances may occur. 3
- Neurological deterioration can be rapid, progressing to seizures, pupillary changes, bradycardia, and respiratory arrest. 9
Frequent neurological assessments are vital to detect early deterioration. 7, 8
Critical Pitfalls to Avoid
- Do not delay descent – Permanent neurological damage occurs if the patient remains unconscious for any prolonged period before descent. 2 Prognosis is good only if descent and treatment start early. 2
- Avoid cerebral vasodilators – Do not use antihypertensive agents that induce cerebral vasodilation, as they worsen intracranial pressure. 7, 8
- Recognize progression risk – Only approximately 1% of acute mountain sickness cases progress to HACE, but when they do, mortality is extremely high without treatment. 1
Prevention Context
While not part of acute management, note that slow ascent (no more than 300-400 meters/day above 2,500 meters) is the primary prevention strategy. 1 Acetazolamide and dexamethasone are effective for preventing acute mountain sickness, which can progress to HACE. 4, 5, 10
Pediatric Considerations
Treat children and adolescents identically to adults with oxygen, immediate descent, and dexamethasone, as HACE can occur in patients as young as 12 years old. 3 There are no specific pediatric guidelines, so adult protocols apply. 3