Barnhart S, Hudson L D, Mason S E, Pierson D J, Rosenstock L
Department of Medicine, University of Washington, Seattle.
Chest. 1988 Feb;93(2):299-302. doi: 10.1378/chest.93.2.299.
The total lung capacity (TLC) is frequently used as a measure of respiratory impairment in patients with asbestosis. Because asbestosis and chronic obstructive pulmonary disease (COPD) exert opposite effects on the TLC, it may be an insensitive measure of impairment in patients with both abnormalities. To assess this, we compared asbestos-exposed patients with functional evidence of COPD and radiographic evidence of interstitial fibrosis (group 1) to those with interstitial fibrosis alone (group 2). Despite the two groups being comparable in degree of radiographic "fibrosis," no case of restrictive impairment (reduced TLC) was identified among those with both interstitial fibrosis and COPD (group 1), compared to 33 percent of those with interstitial fibrosis alone (group 2). In addition, those patients with both interstitial fibrosis and COPD, compared to those with interstitial fibrosis alone, were found to have greater impairment as measured by alveolar-arterial oxygen difference and diffusing capacity. We conclude that the TLC is an insensitive measure of impairment due to asbestosis in patients with the common setting of coexistent asbestosis and COPD.
总肺容量（TLC）常被用作衡量石棉肺患者呼吸功能损害的指标。由于石棉肺和慢性阻塞性肺疾病（COPD）对TLC产生相反的影响，因此它可能是对同时存在这两种异常情况的患者的功能损害不敏感的指标。为了评估这一点，我们将有COPD功能证据和间质性纤维化影像学证据的石棉暴露患者（第1组）与仅患有间质性纤维化的患者（第2组）进行了比较。尽管两组在影像学“纤维化”程度上具有可比性，但与仅患有间质性纤维化的患者（第2组）中33%的患者相比，同时患有间质性纤维化和COPD的患者（第1组）中未发现限制性损害（TLC降低）的病例。此外，与仅患有间质性纤维化的患者相比，同时患有间质性纤维化和COPD的患者经肺泡-动脉血氧分压差和弥散能力测量显示出更严重的功能损害。我们得出结论，在同时存在石棉肺和COPD的常见情况下，TLC是衡量石棉肺所致功能损害的不敏感指标。
