Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan.
Respir Physiol Neurobiol. 2013 Oct 1;189(1):42-6. doi: 10.1016/j.resp.2013.06.018. Epub 2013 Jun 28.
The nitrogen (N₂) single-breath washout (SBW) test is a measure of ventilation distribution inhomogeneity and also a small airway function that offers complementary information to spirometry; however, the relevance to the forced oscillation technique (FOT) and pulmonary emphysema in COPD is not fully understood. We hypothesized that pulmonary functions, forced oscillatory parameters, and emphysema extent would contribute independently to the results of the SBW test. In this cross-sectional study we assessed the relationship between the phase III slope (delta N₂) derived from N₂ SBW and these parameters. Spirometry, lung volumes, N₂ SBW, and the broadband frequency FOT were performed in 56 patients with COPD. Emphysema extent was measured by high-resolution computed tomography and scored. In multiple regression analyses, the delta N₂ was independently predicted by forced vital capacity, resonant frequency, and emphysema score (R(2)=0.57, p<0.0001). The degree of ventilation inhomogeneity derived from N₂ SBW is independently predicted by spirometry, lung mechanics, and the degree of emphysema.
氮气（N₂）单次呼吸清除（SBW）试验是衡量通气分布不均匀性和小气道功能的一种方法，可提供与肺活量计互补的信息；然而，其与 COPD 中的强迫振荡技术（FOT）和肺气肿的相关性尚未完全清楚。我们假设肺功能、强迫振荡参数和肺气肿程度将独立影响 SBW 试验的结果。在这项横断面研究中，我们评估了源自 N₂ SBW 的相位 III 斜率（δ N₂）与这些参数之间的关系。对 56 例 COPD 患者进行了肺活量计检查、肺容积、N₂ SBW 和宽带频率 FOT 检查。通过高分辨率计算机断层扫描测量并评分肺气肿程度。在多元回归分析中，δ N₂可由用力肺活量、共振频率和肺气肿评分独立预测（R²=0.57，p<0.0001）。源自 N₂ SBW 的通气不均匀程度可由肺活量计、肺力学和肺气肿程度独立预测。
