Overview
High altitude cerebral edema (HACE) is a severe, potentially fatal neurological complication of acute exposure to high altitude, characterized by impaired cognitive function, ataxia, and in severe cases, loss of consciousness due to brain swelling caused by hypoxia 16.Diagnosis
Clinical Symptoms: Confusion, lethargy, altered mental status, ataxia, and potentially coma 16.
Grading: Often assessed using a scale where Grade I involves mild symptoms like headache and fatigue, Grade II includes nausea, vomiting, and gait disturbances, while Grade III involves severe confusion, loss of coordination, and potentially coma 1.
Diagnostic Tests: No specific tests; diagnosis is clinical, often requiring rapid descent as initial management 16.Management
First-Line Treatment: Immediate descent to lower altitude 16.
Adjunctive Treatments:
- Oxygen Therapy: Administer supplemental oxygen if available 6.
- Acetazolamide: Can be used to treat milder symptoms and aid acclimatization, typically starting at 250 mg twice daily 16.
- Nifedipine: May be considered for its vasodilatory effects, though evidence is limited 6.Special Populations
Commercial Expeditions: Medications for high-altitude illnesses are not routinely carried by commercial operators, highlighting the need for self-sufficiency in emergency medication 5.
Athletes and Adventurers: Preparticipation evaluations should assess cardiovascular and lung diseases, as these conditions can exacerbate high-altitude illnesses 4.Key Recommendations
Immediate Descent: Rapid descent to lower altitude is critical for managing HACE (Evidence: Strong 16).
Supplemental Oxygen: Provide supplemental oxygen if available to alleviate hypoxia (Evidence: Moderate 6).
Acetazolamide Administration: Use acetazolamide for symptom management and acclimatization support in appropriate cases (Evidence: Moderate 16).
Preparticipation Evaluation: Conduct thorough evaluations focusing on cardiovascular and pulmonary health for athletes and adventurers before high-altitude activities (Evidence: Expert opinion 4).
Carry Emergency Medications: Commercial operators and individuals should carry essential medications for high-altitude illnesses despite current practices (Evidence: Expert opinion 5).References
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3 Lankford HV. Dull Brains, Mountaineers, and Mosso: Hypoxic Words from on High. High altitude medicine & biology 2015. link
4 Campbell AD, McIntosh SE, Nyberg A, Powell AP, Schoene RB, Hackett P. Risk Stratification for Athletes and Adventurers in High-Altitude Environments: Recommendations for Preparticipation Evaluation. Wilderness & environmental medicine 2015. link
5 Pattenden HA, Shah NM, Hillebrandt D, Rodger M, Windsor JS. Do British commercial mountaineering expeditions carry drugs to treat high altitude illnesses?. Journal of travel medicine 2012. link
6 Leissner KB, Mahmood FU. Physiology and pathophysiology at high altitude: considerations for the anesthesiologist. Journal of anesthesia 2009. link
7 Thole RT. Preparation and medical management of events in mountain and high-altitude environments. Current sports medicine reports 2004. link
8 Kassirer MR, Such RV. Persistent high-altitude headache and aguesia without anosmia. Archives of neurology 1989. link
9 Heath D. The morbid anatomy of high altitude. Postgraduate medical journal 1979. link