Ventilation inhomogeneity: alveolar mechanics and gas distribution.
The effects of regional lung differences in alveolar mechanics on the transpulmonary pressure-volume (Ptp-V) relationship and the single-breath washout (SBW) of nitrogen were investigated by mathematical modeling and postmorten human lung experiments. Regional nonuniformity in alveolar collapse and re-opening were associated with differences in gravitational stress or elasticity. Model simulations predict that neither type of regional nonuniformity qualitatively affects the shape of the Ptp-V curve, but does affect the terminal (or small-volume) portion of the SBW. Comparisons of characteristics of the Ptp-V and SBW curves indicate that regional nonuniformity in alveolar collapse is an important mechanism associated with ventilation inhomogeneity.
D000328:Adult; D002102:Cadaver; D006801:Humans; D008170:Lung Compliance; D008176:Lung Volume Measurements; D008962:Models, Theoretical; D011650:Pulmonary Alveoli / Q000502:physiology*; D011659:Pulmonary Gas Exchange; D012119:Respiration