Randomized, placebo controlled trial evaluating efficacy of dexamethasone in preventing acute mountain sickness in lowlanders with chronic obstructive lung disease travelling from 700 m to 3200 m.

This is a randomized, placebo-controlled, double-blind parallel trial evaluating the efficacy of dexamethasone prophylaxis in reducing the incidence of acute mountain sickness in lowlanders with chronic obstructive pulmonary disease travelling to altitude. Participants living in the Bishkek area, Kyrgyzstan (700m), will be transferred by car within 4h to the Tuja Ashu high altitude clinic (3200 m), and stay there for 2 days. Dexamethasone 2x4mg/day (or placebo), will be administered before departure at 700 m and during the stay at altitude. Outcomes will be assessed during the stay at 3200 m.

Inclusion Criteria:

• Chronic obstructive pulmonary disease (COPD), GOLD grade 1-2
• Living at low altitude (<800m)

Exclusion Criteria:

• COPD exacerbation
• severe COPD, GOLD grade 3 or 4
• arterial oxygen saturation <92% at low altitude (<800 m)
• Diabetes, uncontrolled cardiovascular disease such as systemic arterial hypertension, coronary artery disease; previous stroke; pneumothorax in the last 2 months, untreated or symptomatic peptic ulcer disease, glaucoma, obstructive sleep apnea.
• Internal, neurologic or psychiatric disease that interfere with protocol compliance including current heavy smoking (>20 cigarettes per day).
• pregnant or nursing patients