Effects of commercial air travel on patients with pulmonary hypertension

Background: Limited data are available on the effects of air travel in patients with pulmonary hypertension (PH), despite their risk of physiologic compromise. We sought to quantify the incidence and severity of hypoxemia experienced by people with PH during commercial air travel. Methods: We recruited 34 participants for a prospective observational study during which cabin pressure, oxygen saturation (SpO₂), heart rate, and symptoms were documented serially at multiple predefined time points throughout commercial flights. Oxygen desaturation was defined as SpO₂ < 85%. Results: Median flight duration was 3.6 h (range, 1.0-7.3 h). Mean ± SD cabin pressure at cruising altitude was equivalent to the pressure 1,968 ± 371 m (6,456 ± 1,218 ft) above sea level (ASL) (maximum altitude = 2,621 m [8,600 ft] ASL). Median change in SpO₂ from sea level to cruising altitude was -4.9% (range, 2.0% to -15.8%). Nine subjects (26% [95% CI, 12%-38%]) experienced oxygen desaturation during flight (minimum SpO ₂ = 74%). Thirteen subjects (38%) reported symptoms during flight, of whom five also experienced desaturations. Oxygen desaturation was associated with cabin pressures equivalent to > 1,829 m (6,000 ft) ASL, ambulation, and flight duration (all P values < .05). Conclusions: Hypoxemia is common among people with PH traveling by air, occurring in one in four people studied. Hypoxemia was associated with lower cabin pressures, ambulation during flight, and longer flight duration. Patients with PH who will be traveling on flights of longer duration or who have a history of oxygen use, including nocturnal use only, should be evaluated for supplemental in-flight oxygen.