Shiraishi Masashi, Higashimoto Yuji, Sugiya Ryuji, Mizusawa Hiroki, Takeda Yu, Noguchi Masaya, Nishiyama Osamu, Yamazaki Ryo, Kudo Shintarou, Kimura Tamotsu, Tohda Yuji, Matsumoto Hisako
Department of Rehabilitation Medicine, Kindai University School of Medicine, Osaka, Japan.
Department of Respiratory Medicine and Allergology, Kindai University School of Medicine, Osaka, Japan.
ERJ Open Res. 2023 Jun 26;9(3). doi: 10.1183/23120541.00079-2023. eCollection 2023 May.
Dynamic lung hyperinflation (DLH) can play a central role in exertional dyspnoea in patients with COPD. Chest radiography is the basic tool for assessing static lung hyperinflation in COPD. However, the predictive capacity of DLH using chest radiography remains unknown. This study was conducted to determine whether DLH can be predicted by measuring the height of the right diaphragm (dome height) on chest radiography.
This single-centre, retrospective cohort study included patients with stable COPD with pulmonary function test, cardiopulmonary exercise test, constant load test and pulmonary images. They were divided into two groups according to the median of changes of inspiratory capacity (ΔIC=IC lowest - IC at rest). The right diaphragm dome height and lung height were measured on plain chest radiography.
Of the 48 patients included, 24 were classified as having higher DLH (ΔIC ≤-0.59 L from rest; -0.59 L, median of all) and 24 as having lower DLH. Dome height correlated with ΔIC (r=0.66, p<0.001). Multivariate analysis revealed that dome height was associated with higher DLH independent of % low attenuation area on chest computed tomography and forced expiratory volume in 1 s (FEV) % predicted. Furthermore, the area under the receiver operating characteristic curve of dome height to predict higher DLH was 0.86, with sensitivity and specificity of 83% and 75%, respectively, at a cut-off of 20.5 mm. Lung height was unrelated to ΔIC.
Diaphragm dome height on chest radiography may adequately predict higher DLH in patients with COPD.
动态肺过度充气（DLH）在慢性阻塞性肺疾病（COPD）患者运动性呼吸困难中可能起核心作用。胸部X线摄影是评估COPD静态肺过度充气的基本工具。然而，利用胸部X线摄影预测DLH的能力尚不清楚。本研究旨在确定通过测量胸部X线摄影上右膈肌高度（穹顶高度）能否预测DLH。
本单中心回顾性队列研究纳入了进行肺功能测试、心肺运动测试、恒负荷测试及肺部影像检查的稳定期COPD患者。根据吸气容量变化中位数（ΔIC = 静息时最低IC - 静息时IC）将他们分为两组。在胸部X线平片上测量右膈肌穹顶高度和肺高度。
纳入的48例患者中，24例被归类为DLH较高（静息时ΔIC≤ -0.59 L；-0.59 L为所有患者的中位数），24例为DLH较低。穹顶高度与ΔIC相关（r = 0.66，p < 0.001）。多因素分析显示，穹顶高度与较高的DLH相关，独立于胸部计算机断层扫描上的低衰减区百分比和预测的1秒用力呼气量（FEV）百分比。此外，穹顶高度预测较高DLH的受试者工作特征曲线下面积为0.86，在截断值为20.5 mm时，敏感性和特异性分别为83%和75%。肺高度与ΔIC无关。
胸部X线摄影上的膈肌穹顶高度可能足以预测COPD患者较高的DLH。
