Diffusion-perfusion inhomogeneity and alveolar-arterial O2 diffusion limitation: theory.
Unequal distribution of pulmonary O2 diffusing capacity (D) to pulmonary blood flow (Q) (D/Q heterogeneity) leads to decreased alveolar O2 exchange efficacy. It is shown on simple models that the effect increases with increasing amount of inequality and with increasing value of the equilibration index, D/(Q beta) (beta, increment in blood O2 content per partial pressure increment). This inhomogeneity effect, if not taken into account, leads to spurious increases of D in hypoxia and with elevated O2 uptake.
Piiper
J
J
Abteilung Physiologie, Max-Planck-Institut für experimentelle Medizin, Göttingen, Germany.
D000818:Animals; D006801:Humans; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000378:metabolism*; D015657:Respiratory Transport / Q000502:physiology*
D010100:Oxygen