Asthma in patients climbing to high and extreme altitudes in the Tibetan Everest region.

Objectives: The aim of this study was to investigate the behavior of asthma in patients traveling to high and extreme altitudes.

Methods: Twenty-four Dutch patients with mild asthma did a trekking at high and extreme altitudes (up to 6410 m = 21030 ft) in the Tibetan Everest region. Asthma symptoms, use of asthma medication, symptoms of acute mountain sickness, spirometry, peripheral oxygen saturation, and heart rate were measured at 1300 m (baseline), and at 3875, 4310, 5175, and 6410 m.