title: Operation Everest. II: Spirometric and radiographic changes in acclimatized humans at simulated high altitudes.
abstract: We report spirometry and radiographic data on eight normal male human subjects during prolonged graded altitude exposure to as high as 8,848 m above sea level in a hypobaric chamber. We found a significant and progressive drop in FVC by 14 +/- 3% over 40 days, which resolved slowly during the first 48 h after descent. With altitude, midrange forced expiratory flow (FEF25-75) increased by 82 +/- 3%, probably because of reduced air density. FEV1, however, did not change. Chest radiographs on subjects taken 2 h after descent to sea level showed a pattern of pulmonary artery enlargement and interstitial edema. These data suggest that increased pulmonary blood volume and edema may be causes of the restricted pulmonary function pattern.
authors: Department of Medicine, University of Colorado Health Sciences Center, Denver.
authors: C H
authors: CH
authors: Welsh
authors: P D
authors: PD
authors: Wagner
authors: J T
authors: JT
authors: Reeves
authors: D
authors: D
authors: Lynch
authors: T M
authors: TM
authors: Cink
authors: J
authors: J
authors: Armstrong
authors: M K
authors: MK
authors: Malconian
authors: P B
authors: PB
authors: Rock
authors: C S
authors: CS
authors: Houston
mesh_terms: D000064:Acclimatization; D000328:Adult; D000531:Altitude; D001794:Blood Pressure; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008450:Maximal Midexpiratory Flow Rate; D011651:Pulmonary Artery / Q000502:physiology / Q000503:physiopathology; D011654:Pulmonary Edema / Q000000981:diagnostic imaging / Q000503:physiopathology; D012123:Pulmonary Ventilation; D011859:Radiography; D013147:Spirometry; D014692:Ventilation-Perfusion Ratio; D014797:Vital Capacity