Stockley James A, Cooper Brendan G, Stockley Robert A, Sapey Elizabeth
Department of Lung Function and Sleep.
Department of Respiratory Medicine, University Hospital Birmingham.
Int J Chron Obstruct Pulmon Dis. 2017 Aug 7;12:2343-2353. doi: 10.2147/COPD.S138540. eCollection 2017.
It is increasingly acknowledged that delays in the diagnosis of chronic inflammatory lung conditions have hampered our understanding of pathogenesis and thus our ability to design efficacious therapies. This is particularly true for COPD, where most patients are diagnosed with moderate-to-severe airflow obstruction and little is known about the inflammatory processes present in early disease. There is great interest in developing screening tests that can identify those most at risk of developing COPD before airflow obstruction has developed for the purpose of research and clinical care. Landmark pathology studies have suggested that damage to the small airways precedes the development of airflow obstruction and emphysema and, thus, presents an opportunity to identify those at risk of COPD. However, despite a number of physiological tests being available to assess small airways function, none have been adopted into routine care in COPD. The reasons that tests of small airways have not been utilized widely include variability in test results and a lack of validated reference ranges from which to compare results for some methodologies. Furthermore, population studies have not consistently demonstrated their ability to diagnose disease. However, the landscape may be changing. As the equipment that delivers tests of small airways become more widely available, reference ranges are emerging and newer methodologies specifically seek to address variability and difficulty in test performance. Moreover, there is evidence that while tests of small airways may not be helpful across the full range of established disease severity, there may be specific groups (particularly those with early disease) where they might be informative. In this review, commonly utilized tests of small airways are critically appraised to highlight why these tests may be important, how they can be used and what knowledge gaps remain for their use in COPD.
人们越来越认识到，慢性炎症性肺部疾病诊断的延迟阻碍了我们对发病机制的理解，进而影响了我们设计有效治疗方法的能力。慢性阻塞性肺疾病（COPD）尤其如此，大多数COPD患者在被诊断时已患有中度至重度气流阻塞，而对于疾病早期存在的炎症过程却知之甚少。开发筛查测试以识别那些在气流阻塞发生之前最有可能患COPD的人群，对于研究和临床护理具有重要意义。具有里程碑意义的病理学研究表明，小气道损伤先于气流阻塞和肺气肿的发生，因此，这为识别COPD高危人群提供了机会。然而，尽管有多种生理测试可用于评估小气道功能，但在COPD的常规护理中均未采用。小气道测试未被广泛应用的原因包括测试结果的变异性以及缺乏一些方法学的有效参考范围来比较结果。此外，人群研究并未始终证明其诊断疾病的能力。然而，情况可能正在发生变化。随着提供小气道测试的设备越来越普及，参考范围正在出现，并且更新的方法专门致力于解决测试性能中的变异性和困难。此外，有证据表明，虽然小气道测试在已确定的疾病严重程度范围内可能并无帮助，但在某些特定人群（尤其是早期疾病患者）中可能会提供有用信息。在这篇综述中，对常用的小气道测试进行了批判性评估，以强调这些测试为何可能重要、如何使用以及在COPD中使用它们仍存在哪些知识空白。
