title: Predicted arterial oxygenation at commercial aircraft cabin altitudes.
abstract: BACKGROUND
  The degree of hypoxia manifested by airline passengers during flight is not well characterized. Statistical models to predict age-specific levels of Pao2 manifest at altitudes between sea level and 8000 ft (Pao2alt) are described.
  
  
  METHODS
  The relationship between age and Pao2 at sea level (Pao2sl) and the relationship between Pao2alt, and Pao2sl, Pco2 at sea level (Pco2sl), and pulmonary health status were investigated using linear regression techniques to analyze previously published data.
  
  
  RESULTS
  In persons with normal pulmonary health, the relationship between Pao2sl (mmHg) and age (yr) was Pao2sl = 105.9 - 0.44 * age (R2 = 0.582, MSE = 25.314); Pco2sl (38.1 +/- 2.8 mmHg) was not related to age over the range 18-75 yr. In persons with chronic obstructive lung disease (COPD), neither Pao2sl (78.2 +/- 11.3 mmHg) nor Pco2sl (40.5 +/- 5.7 mmHg) were related to age (77.0 +/- 9.0 yrs).The relationship between PaO2alt and Pao2sl, Pco2sl and altitude (ft) was: Pao2alt = 1.59 + 0.98 * Pao2sl + 0.0031 * Alt - 0.000061 * Pao2sl * Alt - 0.000065 * PCO(2)sl [corrected] * Alt + 0.000000092 * Alt2 (R2 = 0.932, MSE = 22.774).
  
  
  CONCLUSIONS
  Pao2sl declines with age in persons with normal pulmonary health; Pco2sl remains constant. Neither vary with age in persons with COPD. Pao2alt can be estimated with acceptable precision from knowledge of Pao2sl, Pco2sl, and altitude. These models predict a substantial proportion of older passengers will manifest a Pao2alt at 8000 ft below the threshold at which supplemental oxygen is recommended.
authors.affiliation: Boeing Medical, The Boeing Company, P.O. Box 3707, MC 7A-XH, Seattle, WA 98124-2207, USA. mike.muhm@boeing.com
authors.forename: J Michael
authors.initials: JM
authors.lastname: Muhm
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000401:Aircraft; D000531:Altitude; D005260:Female; D005544:Forecasting; D006801:Humans; D000860:Hypoxia / Q000209:etiology; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D010100:Oxygen / Q000097:blood*; D011312:Pressure; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications; D012044:Regression Analysis
chemical_list: D010100:Oxygen