Abstract
一氧化氮的肺转移因子(TL,NO) is a new test for pulmonary gas exchange. The procedure is similar to the already well-established transfer factor of the lung for carbon monoxide (Tl,co)。Physiologically,TL,NOpredominantly measures the diffusion pathway from the alveoli to capillary plasma. In the Roughton–Forster equation,TL,NOacts as a surrogate for the membrane diffusing capacity (DM)。红细胞对一氧化碳摄取的耐药性约占气体到血液的总耐药性的50%,但对于一氧化氮而言,这占其耐药性。
TL,NO和Tl,cocan be measured simultaneously with the single breath technique, andDM和肺毛细血管血容量(Vc) can be estimated.TL,NO, unlikeTl,co, is independent of oxygen tension and haematocrit. TheTL,NO/Tl,coratio is weighted towards theDM/Vcratio and to α; where α is the ratio of physical diffusivities of NO to CO (α=1.97). TheTL,NO/Tl,coratio is increased in heavy smokers, with and without computed tomography evidence of emphysema, and reduced in the voluntary restriction of lung expansion; it is expected to be reduced in chronic heart failure. TheTL,NO/Tl,coratio is a new index of gas exchange that may, more than derivations from them ofDM和Vcwith their in-built assumptions, give additional insights into pulmonary pathology.
Footnotes
Previous articles in this series: No. 1:Naeije R, Vachiery J-L, Yerly P,et al.The transpulmonary pressure gradient for the diagnosis of pulmonary vascular diseases.EUR RESSIR j2013; 41: 217–223.
利益声明
没有人宣布。
- ReceivedMay 25, 2012.
- AcceptedAugust 6, 2012.
- ©ERS 2013