Fielding David I, Travers Justin, Nguyen Phan, Brown Michael G, Hartel Gunter, Morrison Stephen
Dept of Thoracic Medicine, Royal Brisbane and Women's Hospital, Herston, Australia.
Dept of Thoracic Medicine, Hutt Valley District Health Board, Lower Hutt, New Zealand.
ERJ Open Res. 2018 Nov 12;4(4). doi: 10.1183/23120541.00080-2018. eCollection 2018 Oct.
Expiratory dynamic airways collapse (EDAC) is a condition that affects the central airways; it is not well characterised physiologically, with relatively few studies. We sought to characterise impulse oscillometry (IOS) features of EDAC in patients with normal spirometry. Expiratory data were hypothesised to be the most revealing. In addition, we compared IOS findings in chronic obstructive pulmonary disease (COPD) patients with and without EDAC. EDAC was identified at bronchoscopy as 75-100% expiratory closure at the carina or bilateral main bronchi. Four patient groups were compared: controls with no EDAC and normal lung function; lone EDAC with normal lung function; COPD-only patients; and COPD patients with EDAC. 38 patients were studied. Mean IOS data z-scores for EDAC compared to controls showed significantly higher reactance () values including at 5 Hz, resonance frequency and area under the reactance curve (A). EDAC showed significantly greater expiratory/inspiratory differences in all IOS data compared to controls. Stepwise logistic regression showed that resonant frequency best discriminated between EDAC and normal control, whereas classification and regression tree analysis found A ≥3.523 to be highly predictive for EDAC in cases with normal lung function (14 out of 15 cases, and none out of eight controls). These data show a new utility of IOS: detecting EDAC in patients with normal lung function.
呼气动态气道塌陷（EDAC）是一种影响中央气道的病症；其生理特征尚未得到充分描述，相关研究较少。我们试图描述肺活量测定正常的患者中EDAC的脉冲振荡法（IOS）特征。我们假设呼气数据最具揭示性。此外，我们比较了有和没有EDAC的慢性阻塞性肺疾病（COPD）患者的IOS结果。在支气管镜检查中，EDAC被确定为在隆突或双侧主支气管处75%-100%的呼气末闭合。比较了四组患者：无EDAC且肺功能正常的对照组；肺功能正常的单纯EDAC患者；仅患有COPD的患者；以及患有COPD且伴有EDAC的患者。共研究了38例患者。与对照组相比，EDAC的平均IOS数据z分数显示电抗（）值显著更高，包括5Hz时的、共振频率和电抗曲线下面积（A）。与对照组相比，EDAC在所有IOS数据中的呼气/吸气差异显著更大。逐步逻辑回归显示，共振频率最能区分EDAC和正常对照组，而分类与回归树分析发现，在肺功能正常的病例中，A≥3.523对EDAC具有高度预测性（15例中有14例，8例对照组中无一例）。这些数据显示了IOS的一种新用途：在肺功能正常的患者中检测EDAC。
