Hypoxia altitude simulation test (HAST) versus hypobaric chamber test (HCT) in COPD patients

Introduction Passengers traveling in an aircraft are exposed to decreased atmospheric and O2 partial pressure, leading to reduced blood O2 saturation (SpO2). Especially COPD patients, depending on disease severity, are highly susceptible for resulting hypoxia due to gas exchange impairments. This can be assessed pre-flight, using a hypobaric chamber test (760 mbar, HCT). We asked if the less elaborate hypoxia altitude simulation test (HAST, inhaled 15.1% O 2 ) can be a reliable alternative in COPD patients. Methods In a mono-center pilot study, 11 COPD patients were exposed to simulated flight conditions using HAST and HCT with continuous SpO2 measurement. Minimun SpO2 (SpO2min) was documented once stable state was reached. Results HAST-SpO2min and HCT-SpO2min showed good correlation (r=0.70, p Discussion The HAST may be used as an easier alternative to the HCT for pre-flight hypoxia assessment of COPD patients. Since it only requires a bottle of hypoxic gas and a suitable patient interface, it is much easier to apply than HCT.