Patients With Chronic Obstructive Pulmonary Disease at Altitude - Effect of Nocturnal Oxygen on Breathing and Sleep
Patients With Chronic Obstructive Pulmonary Disease at Altitude - Effect of Nocturnal Oxygen on Breathing and Sleep
The purpose of this study is to investigate the effect of nocturnal oxygen therapy during a
 stay at moderate altitude on breathing and sleep of patients with chronic obstructive lung
 disease.
Patients with moderate to severe chronic obstructive pulmonary disease living below 800 m
 will be invited to participate in a randomized, cross-over field trial evaluating the
 hypothesis that nocturnal breathing and sleep during nights spent at moderate altitude are
 improved by oxygen therapy via a nasal cannula compared to room air (sham oxygen). Outcomes
 will be assessed at low altitude (Zurich, 490 m, baseline), and during 2 study periods of 2
 nights each spent at moderate altitude (St. Moritz Salastrains, 2048 m) separated by a
 wash-out period of at least 2 weeks spent at low altitude (<800 m).
Inclusion Criteria:

 -  chronic obstructive pulmonary disease (COPD), GOLD grade 2-3

 -  residents at low altitude (<800 m)

 Exclusion Criteria:

 -  unstable condition, COPD exacerbation

 -  mild (GOLD 1) or very severe COPD (GOLD 4)

 -  requirement for oxygen therapy at low altitude residence

 -  hypoventilation

 -  pulmonary hypertension

 -  more than mild or unstable cardiovascular disease

 -  use of drugs that affect respiratory center drive

 -  internal, neurologic or psychiatric disease that interfere with protocol compliance
 including current heavy smoking (>20 cigarettes per day), inability to perform 6 min
 walk test.

 -  previous intolerance to moderate altitude (<2600m).

 -  exposure to altitudes >1500m for >2 days within the last 4 weeks before the study.

 -  pregnant or nursing patients