Effects of ventilation-perfusion inequality on elimination of inert gases

Abstract

Since elimination of an inert gas by the lung depends on the a/ ratio, elements which have different ratios will show a different pattern of elimination. Alveoli having a high a/ will contribute to the “alveolar dead space.” However, the extent of this contribution depends on the gas considered, with gases of low solubility being better suited for detecting these hyperventilated elements. Alveoli with a low a/ contribute to the “venous admixture,” the effect being more pronounced with gases of high solubility. Consideration of the simultaneous elimination of two different inert gases allows to draw a a/ line for these two gases. This can be used to assess a/ inhomogeneity in terms of a two-compartment model.