Alter Peter, Orszag Jan, Kellerer Christina, Kahnert Kathrin, Speicher Tim, Watz Henrik, Bals Robert, Welte Tobias, Vogelmeier Claus F, Jörres Rudolf A
Dept of Medicine, Pulmonary and Critical Care Medicine, Philipps University of Marburg (UMR), member of the German Center for Lung Research (DZL), Marburg, Germany.
Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Comprehensive Pneumology Center Munich (CPC-M), member of the DZL, Munich, Germany.
ERJ Open Res. 2020 Jul 27;6(3). doi: 10.1183/23120541.00092-2020. eCollection 2020 Jul.
Air trapping and lung hyperinflation are major determinants of prognosis and response to therapy in chronic obstructive pulmonary disease (COPD). They are often determined by body plethysmography, which has limited availability, and so the question arises as to what extent they can be estimated spirometry.
We used data from visits 1-5 of the COPD cohort COSYCONET. Predictive parameters were derived from visit 1 data, while visit 2-5 data was used to assess reproducibility. Pooled data then yielded prediction models including sex, age, height, and body mass index as covariates. Hyperinflation was defined as ratio of residual volume (RV) to total lung capacity (TLC) above the upper limit of normal. (ClinicalTrials.gov identifier: NCT01245933).
Visit 1 data from 1988 patients (Global Initiative for Chronic Obstructive Lung Disease grades 1-4, n=187, 847, 766, 188, respectively) were available for analysis (n=1231 males, 757 females; mean±sd age 65.1±8.4 years; forced expiratory volume in 1 s (FEV) 53.1±18.4 % predicted (% pred); forced vital capacity (FVC) 78.8±18.8 % pred; RV/TLC 0.547±0.107). In total, 7157 datasets were analysed. Among measures of hyperinflation, RV/TLC showed the closest relationship to FEV % pred and FVC % pred, which were sufficient for prediction. Their relationship to RV/TLC could be depicted in nomograms. Even when neglecting covariates, hyperinflation was predicted by FEV % pred, FVC % pred or their combination with an area under the curve of 0.870, 0.864 and 0.889, respectively.
The degree of air trapping/hyperinflation in terms of RV/TLC can be estimated in a simple manner from forced spirometry, with an accuracy sufficient for inferring the presence of hyperinflation. This may be useful for clinical settings, where body plethysmography is not available.
气体潴留和肺过度充气是慢性阻塞性肺疾病（COPD）预后及对治疗反应的主要决定因素。它们通常通过体容积描记法来测定，但该方法的可用性有限，因此就产生了一个问题，即通过肺活量测定法在多大程度上可以对其进行估计。
我们使用了COPD队列研究COSYCONET第1 - 5次访视的数据。预测参数来自第1次访视的数据，而第2 - 5次访视的数据用于评估可重复性。汇总数据随后产生了包含性别、年龄、身高和体重指数作为协变量的预测模型。肺过度充气定义为残气量（RV）与肺总量（TLC）之比高于正常上限。（ClinicalTrials.gov标识符：NCT01245933）。
有1988例患者的第1次访视数据（慢性阻塞性肺疾病全球倡议分级1 - 4级，分别为n = 187、847、766、188例）可用于分析（n = 1231例男性，757例女性；平均±标准差年龄65.1±8.4岁；第1秒用力呼气容积（FEV）为预测值的53.1±18.4%（%pred）；用力肺活量（FVC）为预测值的78.8±18.8%pred；RV/TLC为0.547±0.107）。总共分析了7157个数据集。在肺过度充气的测量指标中，RV/TLC与FEV%pred和FVC%pred的关系最为密切，足以进行预测。它们与RV/TLC的关系可以用列线图表示。即使忽略协变量，通过FEV%pred、FVC%pred或它们的组合来预测肺过度充气时，曲线下面积分别为0.870、0.864和0.889。
就RV/TLC而言，气体潴留/肺过度充气的程度可以通过简易肺活量测定法进行估计，其准确性足以推断肺过度充气的存在。这对于无法进行体容积描记法的临床环境可能是有用的。
