High-Altitude Acute Hypoxia Endurance and Comprehensive Lung Function in Pilots.

Abstract

Introduction: High-altitude hypoxia remains one of the primary causes endangering flight safety to this day. This study explores the correlation between pilots' acute hypoxia endurance at high altitude and their comprehensive pulmonary function to help with pilot selection, training, and operations.

Methods: We selected 175 pilots (all men) at the Air Force Medical Center from January 2022 to March 2023. They underwent comprehensive pulmonary function tests and a simulated 22,965-ft (7000-m) hypoxia tests which were categorized into long-time (>360 s) or short-time (180 -360 s) groups based on endurance time. A multivariate Cox proportional risk model analyzed the link between lung function and hypoxia endurance.

Results: All pilots completed the tests with a median hypoxia endurance time of 260 s. The long-time group consisted of 50.3% of the pilots and the short-time group consisted of 49.7%. The Cox model indicated that higher alveolar volume as a percentage of predicted and lower residual volume to total lung capacity ratio as a percentage of predicted significantly influenced hypoxia endurance time, while other variables showed no significant impact.

Discussion: Pilots with higher alveolar volume as a percentage of predicted and lower residual volume to total lung capacity ratio as a percentage of predicted in comprehensive lung function are likely to have better gas exchange efficiency and lung function, leading to longer acute high-altitude hypoxia endurance time. Li B, Xu Y, Wang D, Wei B, Zhu H, Wu M, Lan X, Yin Q, Cao Y. High-altitude acute hypoxia endurance and comprehensive lung function in pilots. Aerosp Med Hum Perform. 2025; 96(3):191-197.