title: Time-based understanding of DLCO and DLNO.
abstract: Capture of CO and NO by blood requires molecules to travel by diffusion from alveolar gas to haemoglobin molecules inside RBCs and then to react. One can attach to these processes two times, a time for diffusion and a time for reaction. This reaction time is known from chemical kinetics and, therefore, constitutes a unique physical clock. This paper presents a time-based bottom-up theory that yields a simple expression for DLCO and DLNO that produces quantitative predictions which compare successfully with experiments. Specifically, when this new approach is applied to DLCO experiments, it can be used to determine the value of the characteristic diffusion time, and the value of capillary volume (Vc). The new theory also provides a simple explanation for still unexplained correlations such as the observed proportionality between the so-called membrane conductance DM and Vc of Roughton and Forster's interpretation. This new theory indicates that DLCO should be proportional to the haematocrit as found in several experiments.
authors: Physique de la Matière Condensée, CNRS, Ecole Polytechnique, 91128 Palaiseau, France.
authors: Min-Yeong
authors: MY
authors: Kang
authors: Physique de la Matière Condensée, CNRS, Ecole Polytechnique, 91128 Palaiseau, France. Electronic address: bernard.sapoval@polytechnique.edu.
authors: Bernard
authors: B
authors: Sapoval
mesh_terms: D000465:Algorithms; D001773:Blood Cells / Q000378:metabolism; D002196:Capillaries / Q000378:metabolism*; D002248:Carbon Monoxide / Q000378:metabolism*; D004058:Diffusion; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D009569:Nitric Oxide / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000378:metabolism*; D012119:Respiration
chemical_list: D006454:Hemoglobins; D009569:Nitric Oxide; D002248:Carbon Monoxide; D010100:Oxygen
keywords: Alveolar-capillary membrane; Capillary volume; DLCO; DLNO; Haematocrit; Heterogeneity