Karvonen Tuomas, Kankaanranta Hannu, Saarelainen Seppo, Moilanen Eeva, Lehtimäki Lauri
Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland.
J Breath Res. 2017 Sep 13;11(4):047102. doi: 10.1088/1752-7163/aa7cc0.
Assessment of the central and peripheral nitric oxide (NO) dynamics of the lung provides information on the severity and anatomical site of pulmonary inflammation. Several mathematical methods for calculating alveolar and bronchial NO parameters have been introduced. Our aim was to compare these methods.
The study included 69 healthy adults, 66 healthy children, 73 asbestos-exposed subjects and 72 subjects with chronic obstructive pulmonary disease (COPD). Exhaled NO was measured at multiple flow rates and we used five mathematical methods (Tsoukias and George, Pietropaoli, Condorelli, Högman and Meriläinen, and Silkoff) to estimate alveolar and bronchial NO parameters.
The Högman and Meriläinen method was less frequently feasible than the other methods but it had the highest degree of agreement with the measured data. The methods were most often feasible in healthy or asbestos-exposed adults but distinctly more infrequently in children and adults with COPD, suggesting difficulties in NO measurements in these groups. The linear methods (Tsoukias and George, Pietropaoli) yielded higher alveolar NO concentration and lower bronchial NO flux than the two non-linear methods (Högman and Meriläinen, Silkoff) and a linear method with correction for axial back-diffusion of NO (Condorelli).
In differentiating central and peripheral NO sources we recommend using linear methods, as low flow rates are not needed and the feasibility of the methods is good. If bronchial wall NO concentration (C NO) and diffusing capacity (D NO) are of interest, non-linear methods are needed, and we recommend using the Högman and Meriläinen method as only three flow rates are needed. However, the agreement between the model and measured data needs to be checked in real time to ensure feasibility. If the subject has difficulties with the extremely low or high flow rates, we then recommend using the Silkoff method to improve feasibility, but more flow rates and measurements are then needed and the agreement between the model and the measured data may be poorer.
评估肺部的中央和外周一氧化氮（NO）动力学可提供有关肺部炎症严重程度和解剖部位的信息。已经引入了几种计算肺泡和支气管NO参数的数学方法。我们的目的是比较这些方法。
该研究纳入了69名健康成年人、66名健康儿童、73名接触石棉的受试者和72名慢性阻塞性肺疾病（COPD）患者。在多个流速下测量呼出的NO，并使用五种数学方法（Tsoukias和George法、Pietropaoli法、Condorelli法、Högman和Meriläinen法以及Silkoff法）来估计肺泡和支气管NO参数。
Högman和Meriläinen法的可行性低于其他方法，但与测量数据的一致性程度最高。这些方法在健康或接触石棉的成年人中最常可行，但在儿童和COPD成年人中明显更不常可行，这表明在这些人群中进行NO测量存在困难。线性方法（Tsoukias和George法、Pietropaoli法）产生的肺泡NO浓度高于两种非线性方法（Högman和Meriläinen法、Silkoff法）以及一种对NO轴向反向扩散进行校正的线性方法（Condorelli法），而支气管NO通量则较低。
在区分中央和外周NO来源时，我们建议使用线性方法，因为不需要低流速且方法的可行性良好。如果关注支气管壁NO浓度（C NO）和扩散能力（D NO），则需要非线性方法，我们建议使用Högman和Meriläinen法，因为只需要三个流速。然而，需要实时检查模型与测量数据之间的一致性以确保可行性。如果受试者在极低或极高流速下存在困难，我们则建议使用Silkoff法以提高可行性，但此时需要更多的流速和测量次数，并且模型与测量数据之间的一致性可能较差。
