Abstract |
DLNO/DLCO directly measures the ratio of the diffusing capacities of the lung for nitric oxide (NO) and carbon monoxide (CO). In terms of the Roughton and Forster (1957) equation, 1/DL=1/Dm+1/θVc, where Dm is the membrane (Dm) and θVc is the red cell component of the overall diffusing conductance (DL); DLNO mostly reflects the Dm component and DLCO the θVc red cell component. The DLNO/DLCO ratio is positively related to the DmCO/Vc ratio and the CO red cell resistance (1/θCOVc) as a percentage of the total resistance (1/DLCO), independent of the absolute values of DLNO or DLCO. In clinical studies, a raised DLNO/DLCO ratio (≥110% predicted versus a control group), plus a low DLNO and DLCO (<67% pred), predicts pulmonary vascular disease, while a low DLNO/DLCO ratio, with similarly reduced DLNO and DLCO, is associated with interstitial lung disease with fibrosis. More clinical studies are needed, and reference values need to be better defined.
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Authors | J M B Hughes, A T Dinh-Xuan |
Journal | Respiratory physiology & neurobiology
(Respir Physiol Neurobiol)
Vol. 241
Pg. 17-22
(07 2017)
ISSN: 1878-1519 [Electronic] Netherlands |
PMID | 28088638
(Publication Type: Journal Article, Review)
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Copyright | Copyright © 2017 Elsevier B.V. All rights reserved. |
Chemical References |
- Nitric Oxide
- Carbon Monoxide
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Topics |
- Animals
- Carbon Monoxide
- Humans
- Lung
(physiology)
- Models, Cardiovascular
- Nitric Oxide
- Pulmonary Diffusing Capacity
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