A first principles calculation of the oxygen uptake in the human pulmonary acinus at maximal exercise

• Tipo: Artigo em Revista Científica Internacional
• Data: 2013

Autores

Foucquier, A (Autor) Outra; Filoche, M (Autor) Outra; Moreira, André (Autor) FMUP; Andrade, JS (Autor) Outra; Arbia, G (Autor) Outra; Sapoval, B (Autor) Outra

Revista

Título: Respiratory Physiology and Neurobiology

Vol. 185

Páginas: 625-638

ISSN: 1569-9048

Editora: Elsevier

Indexação

Scopus - 14 Citações

Outras Informações

ID Authenticus: P-00G-6Z4

DOI: 10.1016/j.resp.2012.10.013

Abstract (EN): It has recently been shown that the acinus can have a reduced efficiency due to a "screening effect" governed by the ratio of oxygen diffusivity to membrane permeability, the gas flow velocity, as well as the size and configuration of the acinus. We present here a top to bottom calculation of the functioning of a machine acinus at exercise that takes this screening effect into account. It shows that, given the geometry and the breathing dynamics of real acini, respiration can be correlated to a single equivalent parameter that we call the integrative permeability. In particular we find that both V¿O2,max and PAO2 depend on this permeability in a non-linear manner. Numerical solutions of dynamic convection-diffusion equations indicate that only a narrow range of permeability values is compatible with the experimental measurements of PAO2 and V¿O2,max. These permeability values are significantly smaller than those found in the literature. In a second step, we present a new type of evaluation of the diffusive permeability, yielding values compatible with the top to bottom approach, but smaller than the usual morphometric value. © 2012 Elsevier B.V.

Idioma: Inglês

Tipo (Avaliação Docente): Científica