Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5594067 | Respiratory Physiology & Neurobiology | 2017 | 6 Pages |
Abstract
The O2 diffusion limitation across the air blood barrier (DO2 and subcomponents Dm and Vc) was evaluated in 17 healthy participants exposed to hypobaric hypoxia (HA, 3840m, PIO2 â¼90Â mmHg). A 10% decrease in alveolar volume (VA) in all participants suggested the development of sub-clinical interstitial lung edema. In >80% of participants DO2/VA increased, reflecting an individual strategy to cope with the hypoxia stimulus by remodulating Vc or Dm. Opposite changes in Dm/Vc ratio were observed and participants decreasing Vc showed reduced alveolar blood capillary transit time. The interplay between diffusion and perfusion (cardiac output) was estimated in order to investigate the individual adaptive response to hypoxia. It appears remarkable that despite individual differences in the adaptive response to HA, diffusion limitation did not exceed â¼11% of the alveolar-venous PO2 gradient, revealing an admirable functional design of the air-blood barrier to defend the O2 diffusion/perfusion function when facing hypobaric hypoxia corresponding to 50Â mmHg decreased PAO2.
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Authors
Egidio Beretta, Francesca Lanfranconi, Gabriele Simone Grasso, Manuela Bartesaghi, Hailu Kinfu Alemayehu, Lorenza Pratali, Bruna Catuzzo, Guido Giardini, Giuseppe Miserocchi,