Hypobaric Hypoxia in Aircrew
a brief review on etiology, risks, and preventive exercises
DOI:
https://doi.org/10.22480/rev.unifa.2025.38.879Keywords:
Hypoxia, Hypobaric, Hypoxia Awereness Training, Hypoxia Symptoms, AircrewAbstract
Hypobaric hypoxia is caused by insufficient oxygen in the crew due to low atmospheric pressure. It causes hypoxemia and the symptoms of hypobaric hypoxia progressively develop, making the crew unable to perform executive functions. Aircraft accidents due to the development of hypobaric hypoxia in the crew have caused hundreds of casualties in the modern era of aviation, involving different aircraft and in other countries. To prevent such accidents, the aircrews perform simulated hypobaric chamber exercises periodically, in this way, it is possible to introduce the symptoms of hypobaric hypoxia to them in a safe and controlled atmosphere. Consequently, this allows them to remember hypoxia symptoms during an eventual aviation incident. The interval between hypobaric chamber exercises varies between countries. Although they are not mandatory, it is suggested that an interval of between three and six years between hypoxia exercises is appropriate to maintain flight safety concerning hypoxia symptoms. However, it is important to be aware that there is intra- and inter-personal variability in hypobaric hypoxia symptoms.
References
ALAGHA, B. et al. Hypoxia symptoms during altitude training in professional Iranian fighter pilots. Air Medical Journal, v. 31, n. 1, p. 28–32, 2012.
ARTINO, A. R.; FOLGA, R. V.; SWAN, B. D. Mask-on hypoxia training for tactical jet aviators: evaluation of an alternate instructional paradigm. Aviation, Space, and Environmental Medicine, v. 77, n. 8, p. 857–863, ago. 2006.
BLACKER, K. J.; MCHAIL, D. G. Time course of recovery from acute hypoxia exposure as measured by vigilance and event-related potentials. Physiology & Behavior, v. 239, p. 113508, 1 out. 2021.
BOUAK, F. et al. Acute Mild Hypoxic Hypoxia Effects on Cognitive and Simulated Aircraft Pilot Performance. Aerospace Medicine and Human Performance, v. 89, n. 6, p. 526–535, 1 jun. 2018.
BRASIL, M. DA DEFESA. C. DA AERONÁUTICA. Instrução Técnica, Comando de Preparo: Ensino - Currículo Mínimo do Curso Básico de Reconhecimento (CBR). ICA 37-796. [s.l: s.n.].
BUSTAMANTE-SÁNCHEZ, Á.; DELGADO-TERÁN, M.; CLEMENTE-SUÁREZ, V. J. Psychophysiological response of different aircrew in normobaric hypoxia training. Ergonomics, v. 62, n. 2, p. 277–285, fev. 2019.
CHIANG, K.-T. et al. Contributions of hypoxia-awareness training to the familiarization of personal symptoms for occupational safety in the flight environment. International journal of environmental research and public health, v. 18, n. 6, p. 2904, 2021.
COX, B. D.; MCHAIL, D. G.; BLACKER, K. J. Personal Hypoxia Symptoms Vary Widely Within Individuals. Aerospace Medicine and Human Performance, v. 95, n. 1, p. 54–58, 1 jan. 2024.
DAVIS, J. R.; JOHNSON, R.; STEPANEK, J. Fundamentals of aerospace medicine. [s.l.] Lippincott Williams & Wilkins, 2008.
FILES, D. S.; WEBB, J. T.; PILMANIS, A. A. Depressurization in military aircraft: rates, rapidity, and health effects for 1055 incidents. Aviation, Space, and Environmental Medicine, v. 76, n. 6, p. 523–529, jun. 2005.
IZRAELI, S. et al. Determination of the “time of useful consciousness” (TUC) in repeated exposures to simulated altitude of 25,000 ft (7,620 m). Aviation, Space, and Environmental Medicine, v. 59, n. 11 Pt 1, p. 1103–1105, nov. 1988.
JOHNSTON, B. J. et al. Hypoxia training: symptom replication in experienced military aircrew. Aviation, space, and environmental medicine, v. 83, n. 10, p. 962–967, 2012.
KUMAR, A. et al. A simulation study to compare physiological responses to hypoxia and exercise between anaemic subjects and healthy controls. Indian Journal of Physiology and Pharmacology, v. 66, p. 181–187, 10 out. 2022.
LEINONEN, A. et al. Normobaric hypoxia training in military aviation and subsequent hypoxia symptom recognition. Ergonomics, v. 64, n. 4, p. 545–552, 3 abr. 2021.
MALLE, C. et al. Working memory impairment in pilots exposed to acute hypobaric hypoxia. Aviation, space, and environmental medicine, v. 84, n. 8, p. 773–779, 2013.
NATION, D. A. et al. Mechanisms of memory dysfunction during high altitude hypoxia training in military aircrew. Journal of the International Neuropsychological Society, v. 23, n. 1, p. 1–10, 2017.
NEUHAUS, C.; HINKELBEIN, J. Cognitive responses to hypobaric hypoxia: implications for aviation training. Psychology research and behavior management, p. 297–302, 2014.
PATRÃO, L. et al. Flight physiology training experiences and perspectives: Survey of 117 pilots. Aviation, Space, and Environmental Medicine, v. 84, n. 6, p. 620–624, 2013.
PHILLIPS, J. B.; HØRNING, D.; FUNKE, M. E. Cognitive and perceptual deficits of normobaric hypoxia and the time course to performance recovery. Aerospace Medicine and Human Performance, v. 86, n. 4, p. 357–365, abr. 2015.
SHAW, D. M.; CABRE, G.; GANT, N. Hypoxic Hypoxia and Brain Function in Military Aviation: Basic Physiology and Applied Perspectives. Frontiers in Physiology, v. 12, p. 665821, 17 maio 2021.
SHAW, D. M.; HARRELL, J. W. Integrating physiological monitoring systems in military aviation: a brief narrative review of its importance, opportunities, and risks. Ergonomics, v. 66, n. 12, p. 2242–2254, 2 dez. 2023.
SINGH, B. et al. Hypoxia awareness training for aircrew: a comparison of two techniques. Aviation, Space, and Environmental Medicine, v. 81, n. 9, p. 857–863, set. 2010.
STEVENSON, K. Hypoxia: an analysis of hypobaric chamber training. [s.l.] Arizona State University, 2019.
TEMME, L. A.; STILL, D. L.; ACROMITE, M. T. Hypoxia and flight performance of military instructor pilots in a flight simulator. Aviation, Space, and Environmental Medicine, v. 81, n. 7, p. 654–659, jul. 2010.
TEMPORAL, W. Medicina Aeroespacial. rio de Janeiro: Luzes, 2004.
TU, M.-Y. et al. Comparison of hypobaric hypoxia symptoms between a recalled exposure and a current exposure. PLoS One, v. 15, n. 9, p. e0239194, 2020.
VARIS, N.; PARKKOLA, K. I.; LEINO, T. K. Hypoxia Hangover and Flight Performance After Normobaric Hypoxia Exposure in a Hawk Simulator. Aerospace Medicine and Human Performance, v. 90, n. 8, p. 720–724, 1 ago. 2019.
WOODROW, A. D.; WEBB, J. T.; WIER, G. S. Recollection of Hypoxia Symptoms Between Training Events. Aviation, Space, and Environmental Medicine, v. 82, n. 12, p. 1143–1147, 1 dez. 2011.
YONEDA, I. et al. Time of useful consciousness determination in aircrew members with reference to prior altitude chamber experience and age. Aviation, Space, and Environmental Medicine, v. 71, n. 1, p. 72–76, jan. 2000.
ZHANG, D. et al. Effects of acute hypoxia on heart rate variability, sample entropy and cardiorespiratory phase synchronization. BioMedical Engineering OnLine, v. 13, n. 1, p. 73, dez. 2014.
Downloads
Published
Issue
Section
License
Copyright (c) 2025 Adriano Percival Calderaro Calvo, Danielle Filippo de Lemos
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Revista da UNIFA permite que o (s) autor (es) mantenha(m) seus direitos autorais sem restrições. Atribuição-NãoComercial 4.0 Internacional (CC BY-NC 4.0) - Revista da UNIFA é regida pela licença CC-BY-NC
