Woolcock Institute of Medical Research, Australia; Cooperative Research Centre for Asthma and Airways, Glebe, St. Leonards, Australia; Department of Respiratory Medicine, Royal North Shore Hospital, St. Leonards, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
Woolcock Institute of Medical Research, Australia; Cooperative Research Centre for Asthma and Airways, Glebe, St. Leonards, Australia.
Chest. 2012 Aug;142(2):312-319. doi: 10.1378/chest.11-2169.
The severities of COPD (FEV(1) % predicted) and airflow obstruction (FEV(1)/FVC) are considered to be due to both emphysema and small airways disease. To our knowledge, this has not been previously confirmed by combined measurements of emphysema and of small airway function. We hypothesized that small airways disease and emphysema extent contribute independently to the severity of both COPD and airflow obstruction.
Twenty-six subjects with COPD underwent measurements with forced oscillation technique (FOT) at 6 Hz and single-breath nitrogen washout. Respiratory system resistance, respiratory system reactance (Xrs), and expiratory flow limitation (EFL) index (measured as mean inspiratory Xrs − expiratory Xrs) were derived from FOT. Closing volume/vital capacity (CV/VC) was derived from the washout. Emphysema extent was measured as low attenuation areas < -910 Hounsfield units, expressed as a percentage of CT scan lung volume from multislice CT scans taken at total lung capacity.
Subjects were aged (mean ± SD) 69.6 ± 8.0 years. Postbronchodilator FEV(1) was 64.8 ± 19.8% predicted, and diffusing capacity of lung for carbon monoxide was 50.7 ± 15.8% predicted. Emphysema extent was 22.6% ± 15.0% CT scan volume. CV/VC was 16.9% ± 7.9%; Xrs, -3.72 ± 3.03 cm H(2)O/L/s; and EFL index, 3.88 ± 3.93 cm H(2)O/L/s. In multiple regression analyses, FEV(1)/FVC was predicted by both emphysema and CV/VC (model r(2) = 0.54, P < .0001) whereas FEV(1) % predicted was predicted by emphysema and EFL index (model r(2) = 0.38, P = .0014).
The severities of COPD and airflow obstruction are independently predicted by both small airways disease and emphysema extent.
COPD 的严重程度（FEV1%预计值）和气流阻塞（FEV1/FVC）被认为是由肺气肿和小气道疾病共同引起的。据我们所知，这尚未通过对肺气肿和小气道功能的联合测量来得到证实。我们假设小气道疾病和肺气肿的严重程度都与 COPD 和气流阻塞的严重程度独立相关。
26 名 COPD 患者接受了 6Hz 强迫振荡技术（FOT）和单口气氮清除测量。呼吸系统阻力、呼吸系统电抗（Xrs）和呼气流量限制（EFL）指数（以平均吸气 Xrs-呼气 Xrs 测量）从 FOT 中得出。闭合容量/肺活量（CV/VC）从清除中得出。肺气肿程度以低衰减区<−910 亨氏单位表示，以多层 CT 扫描在总肺活量时的 CT 扫描肺体积的百分比表示。
患者年龄（平均值±标准差）为 69.6±8.0 岁。支气管扩张剂后 FEV1 为 64.8±19.8%预计值，一氧化碳弥散量为 50.7±15.8%预计值。肺气肿程度为 22.6%±15.0%CT 扫描体积。CV/VC 为 16.9%±7.9%；Xrs，−3.72±3.03cmH2O/L/s；EFL 指数为 3.88±3.93cmH2O/L/s。多元回归分析显示，FEV1/FVC 由肺气肿和 CV/VC 共同预测（模型 r2=0.54，P<0.0001），而 FEV1%预计值由肺气肿和 EFL 指数预测（模型 r2=0.38，P=0.0014）。
COPD 和气流阻塞的严重程度由小气道疾病和肺气肿程度独立预测。
