title: Effects of altitude-related hypoxia on aircrews in aircraft with unpressurized cabins.
abstract: BACKGROUND
  Generally, hypoxia at less than 10,000 ft (3,048 m) has no apparent effect on aircrews. Nevertheless, several hypoxic incidents have been reported in flights below 10,000 ft. A recently introduced pulse oximeter using finger probes allows accurate monitoring of oxygen saturation (SPO2) in the aeromedical environment. Using such a pulse oximeter, in-flight SPO2 levels were evaluated in aircrew in unpressurized aircraft. In addition, career in-flight hypoxic experiences were surveyed.
  
  
  METHODS
  In-flight SPO2 was measured in aircrews operating UH-60J helicopters at up to 13,000 ft, and 338 aircrew members operating unpressurized cabin aircraft were surveyed concerning possible in-flight hypoxic experiences.
  
  
  RESULTS
  In aircrews operating UH-60J helicopters, SPO2 decreased significantly at altitudes over 5,000 ft, most markedly at 13,000 ft (vs. ground level). The survey identified three aircrew members with experiences suggesting hypoxemia at below 5,000 ft.
  
  
  CONCLUSIONS
  Careful attention should be paid to the possibility of hypoxia in aircrews operating unpressurized cabin aircraft.
authors.affiliation: Aeromedical Laboratory, Japan Air Self-Defense Force 1-2-10, Sakaecho, Tachikawa, Tokyo 190-8585, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Nishi
mesh_terms: D000328:Adult; D000337:Aerospace Medicine; D000401:Aircraft; D000531:Altitude; D000704:Analysis of Variance; D001274:Atmospheric Pressure; D016009:Chi-Square Distribution; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D010101:Oxygen Consumption / Q000502:physiology; D011795:Surveys and Questionnaires