Division of Respirology, Department of Medicine, Royal University Hospital, Saskatoon, Saskatchewan.
Can Respir J. 2011 Sep-Oct;18(5):e73-6. doi: 10.1155/2011/354325.
Pulmonary function tests in patients with idiopathic pulmonary fibrosis characteristically show a restrictive pattern including small lung volumes and increased expiratory flow rates resulting from a reduction in pulmonary compliance due to diffuse fibrosis. Conversely, an obstructive pattern with hyperinflation results in emphysema by loss of elastic recoil, expiratory collapse of the peripheral airways and air trapping. When the diseases coexist, pulmonary volumes are compensated, and a smaller than expected reduction or even normal lung volumes can be found. The present report describes 10 patients with progressive breathlessness, three of whom experienced severe limitation in their quality of life. All patients showed lung interstitial involvement and emphysema on computed tomography scan of the chest. The 10 patients showed normal spirometry and lung volumes with severe compromise of gas exchange. Normal lung volumes do not exclude diagnosis of idiopathic pulmonary fibrosis in patients with concomitant emphysema. The relatively preserved lung volumes may underestimate the severity of idiopathic pulmonary fibrosis and attenuate its effects on lung function parameters.
特发性肺纤维化患者的肺功能检查通常表现为限制性模式，包括肺容积小和呼气流量率增加，这是由于弥漫性纤维化导致肺顺应性降低所致。相反，肺气肿则表现为阻塞性模式，由于弹性回缩力丧失、外周气道呼气性塌陷和空气滞留导致过度充气。当这些疾病共存时，肺容积得到代偿，可能会发现比预期更小或甚至正常的肺容积。本报告描述了 10 例进行性呼吸困难的患者，其中 3 例患者的生活质量受到严重限制。所有患者的胸部计算机断层扫描均显示肺间质受累和肺气肿。这 10 例患者的肺功能检查和肺容积均正常，但气体交换严重受损。正常的肺容积并不能排除同时患有肺气肿的特发性肺纤维化的诊断。相对保留的肺容积可能会低估特发性肺纤维化的严重程度，并减弱其对肺功能参数的影响。
