title: Comparison of single breath and steady state methods for the measurement of pulmonary diffusing capacity for carbon monoxide in non-homogeneous lungs.
abstract: The effect of non-uniformity in the distribution of ventilation and diffusion on the apparent pulmonary diffusing capacity measured by the single breath and steady state techniques has been assessed on the basis of a two-compartmental lung model. Both the methods give reasonable estimates of the true diffusing capacity provided the fast compartment has a greater KCO. The reverse of this results in gross underestimation of the diffusing capacity by both methods. There is a fairly good correlation between the single breath and the steady state results both in theory as well as in practice.
mesh_terms: D002248:Carbon Monoxide; D004058:Diffusion; D006801:Humans; D008433:Mathematics; D008954:Models, Biological; D011658:Pulmonary Fibrosis / Q000378:metabolism; D012119:Respiration; D012129:Respiratory Function Tests
chemical_list: D002248:Carbon Monoxide