What is the treatment for a patient with altitude sickness?

Treatment of Altitude Sickness

Immediate descent to lower altitude combined with supplemental oxygen is the primary treatment for all forms of altitude sickness, with pharmacological therapy serving as an adjunct when descent is not immediately possible. 1, 2

Initial Management Algorithm

Mild Acute Mountain Sickness (AMS)

• Stop further ascent and rest at current altitude until symptoms resolve 1
• Administer acetazolamide 250 mg twice daily or 500 mg once daily to accelerate acclimatization 1, 3
• Ensure adequate hydration, as dehydration worsens symptoms 1
• Use acetaminophen or ibuprofen for headache relief (though if headache is not relieved by acetaminophen, this may indicate progression to severe AMS) 3

Severe AMS/High-Altitude Cerebral Edema (HACE)

• Descend immediately—this is non-negotiable for severe cases 4, 5
• Administer dexamethasone as first-line treatment: large intravenous doses are recommended for the malignant cerebral form 3, 4
• Provide supplemental oxygen to maintain saturation >91% 2
• Consider diuretics (furosemide) and hyperosmolar agents (mannitol, urea, 50% saline, or 50% sucrose) as adjunctive therapy 4
• Prognosis is good if descent and treatment start early, but permanent neurological damage occurs if the patient remains unconscious for prolonged periods before descent 4

High-Altitude Pulmonary Edema (HAPE)

• Immediate descent and supplemental oxygen are the primary therapies 1, 2
• Initiate oxygen therapy with a reservoir mask at 15 L/min to achieve saturation of 94-98% 2
• Maintain absolute rest, as even light exercise worsens hypoxemia 2
• Administer nifedipine 20 mg extended-release every 8 hours as adjunctive therapy when descent or oxygen are not immediately available 2, 3
• Nifedipine reduces pulmonary arterial pressure and improves oxygenation 2
• Patients typically improve rapidly with enriched inspired oxygen, with symptoms appearing 2-4 days after rapid ascent 2

Medication-Specific Guidance

Acetazolamide

• Effective for both prevention and treatment of mild AMS 1, 6, 7
• Mechanism: carbonic anhydrase inhibitor causing mild diuresis and metabolic acidosis, which stimulates ventilation and improves oxygenation 1
• Common side effects include paresthesias, vertigo, and unpleasant taste—generally mild but dose-related 1
• Prolonged use beyond 2-3 days at terminal altitude is unnecessary and increases cumulative side effects 1
• May reduce subendocardial ischemia risk at high altitude 1

Dexamethasone

• First-line treatment for severe AMS and early HACE, but not effective for advanced cerebral edema 6, 3
• Alternative to acetazolamide when sulfa intolerance exists 6
• Side effects limit its use for prophylaxis 6

Nifedipine

• Medication of choice specifically for HAPE treatment and prevention 1, 2, 3
• For patients with prior HAPE history: start with ascent and continue 3-4 days after arrival at terminal altitude 1, 2
• RCT evidence shows reduced HAPE incidence from 7 of 11 (placebo) to 1 of 10 (treated) in adults with prior HAPE 2
• Patients with previous HAPE episode have 62% recurrence rate with rapid ascent to 4559 m, making prophylaxis essential 1, 2

Critical Pitfalls to Avoid

• Never delay descent for severe cases (HACE or HAPE)—two deaths reported in the literature occurred when evacuation was delayed 4
• Do not underestimate the importance of absolute rest in HAPE, as exercise worsens hypoxemia 2
• Avoid inadequate hydration, which exacerbates all forms of altitude sickness 1
• Do not continue ascent if initial symptoms appear—this is when acclimatization must occur 1
• Recognize warning signs of progression: vomiting (not just nausea), severe headache unrelieved by acetaminophen, ataxia, and mental deterioration indicate severe disease requiring immediate descent 3, 4

Special Population Considerations

Cardiovascular Disease Patients

• Continue pre-existing cardiovascular medications throughout altitude exposure 1
• Acetazolamide can be added for AMS prevention using the same 2-3 day post-arrival duration 1
• For heart failure patients, carefully evaluate acetazolamide use with other diuretics due to dehydration and electrolyte imbalance risk 1

Pediatric Patients

• All recommendations are based on adult trials, as no randomized trials exist for children 1, 2
• Apply same principles: immediate descent, oxygen, and similar medication dosing adjusted for weight 1, 2
• HAPE in children is associated with viral illness and disorders including ASD, PDA, pulmonary vein stenosis, trisomy 21, and BPD 2