Analysis of Altitude Hypoxia Training and In-Flight Hypoxia Events among the Helicopter Aircrews

Abstract

All aircrews are required to undertake the altitude hypoxia training and be familiarized with the hypobaric effect on their physiological regulation. Due to the characteristics of the helicopter aircrafts, few researches have reported in-flight hypoxia events among the helicopter aircrews. The main goal of this study was designed to compare the hypoxia symptoms of helicopter aircrews between the altitude hypoxia training and during flight. We developed a questionnaire to collect the details of chamber flights and in-flight hypoxia events in 2019. All data were managed by the SPSS software and two-tailed 0.05 alpha level was considered as a significant level. Of the 213 study participants, there were eight (3.8%) cases that experienced hypoxia symptoms during the flight. The top five symptoms that appeared both in the last and current altitude hypoxia trainings were visual impairment (20.7%), difficulty concentrating (12.7%), tiredness (12.2%), cognitive impairment (8.0%), and air hunger (5.2%). Meanwhile, the frequency of those symptoms above was not significantly different from the last or current training compared with those in-flight hypoxia events. The survey unveiled a series of consistency correlations of hypoxia symptoms between the chamber flights and in-flight environment for the helicopter aircrew group.

Oxidative Stress, Hypoxia-Inducible Factor-1α, and Nuclear Factor-Erythroid 2-Related Factor 2 in the Hearts of Rats Exposed to Intermittent Hypobaric Hypoxia

“…In the present study, rats were exposed to hypobaric hypoxia simulating an altitude of 3,048 m (10,000 ft) for 1 h. This altitude was chosen based on the general view that at 3,048 m (the socalled physiological altitude in aviation medicine) flight capability remains unaffected (Gonchar and Mankovska 2010). However, even exposure to altitudes below 3,048 m in a depressurized chamber can elicit error proneness, slower reactions, physical fatigue, cognitive problems, and poor concentration (Chiang et al 2021). Our hypobaric hypoxia treatment protocol can be classified as sub-chronic IHH (SCIHH), since the animals were exposed for 1 h to hypobaric hypoxia daily.…”