Occurs 48-72 hours after arrival at altitude. Immediate descent to lower altitude. If able because of weather, or transportation then oxygen and bed rest may help. Hyperbaric therapy is effective and practical if descent not possible. A portable hyperbaric chamber, the Gamow Bag can be inflated to 2 pounds per square inch using a foot pump.
Improvement is usually immediate.
Allow two days for each 1000 feet above 14,000 feet. Maintain adequate hydration-dehydration increases likelihood and makes symptoms worse. Prophylaxis given only if patient has a history of altitude sickness or plans on rapid ascent to altitudes above 8000 feet. Dexamethasone 2-4 mg q6 hours, begun the day of descent and continued for three days at higher altitude may significantly reduce incidence and severity. Current concepts, acute mountain sickness.