Hypoxaemia in chronic obstructive pulmonary disease patients during a commercial flight

The aim of the study was to investigate hypoxaemia in chronic obstructive pulmonary disease patients during a commercial flight. The effect of a commercial flight, lasting 5 h 40 min, on arterial blood gas levels and symptoms in 18 chronic obstructive pulmonary disease patients with a pre-flight percutaneous oxygen saturation of >= 94 % and self-reported ability to walk 50 m without severe dyspnoea was studied. The arterial oxygen tension (Pa,O-2) decreased from sea level to cruising altitude (10.3 +/- 1.2 versus 8.6 +/- 0.8 kPa), thereafter, except for one patient, remained stable throughout the flight. During light exercise, however, there was further desaturation (percutaneous oxygen saturation 90 +/- 4 versus 87 +/- 4 %). After 4 h, a decrease in arterial carbon dioxide tension (5.0 +/- 0.4 versus 4.8 +/- 0.4 kPa) and an increase in cardiac frequency (87 +/- 13 versus 95 +/- 13 beats(.)min(-1)) were observed. A pre-flight Pa,O-2 of > 9.3 kPa did not secure an acceptable in-flight Pa,O-2. Aerobic capacity showed the strongest correlation with in-flight ill In conclusion, following an initial decrease in arterial oxygen tension, chronic obstructive pulmonary disease patients in a stable state of their disease seem to maintain a stable arterial oxygen tension throughout a flight of intermediate duration, except when walking along the aisle. However, a decrease in arterial carbon dioxide tension, indicating compensatory hyperventilation, could imply a risk of respiratory fatigue during longer flights.