Respiratory Function Laboratory, 1st Dept of Respiratory Medicine, National and Kapodistrian University of Athens Medical School, Sotiria Hospital, 152 Mesogeion Ave., Athens, Greece.
Eur Respir Rev. 2011 Sep 1;20(121):147-55. doi: 10.1183/09059180.00001911.
Patients with severe chronic obstructive pulmonary disease (COPD) often exhale along the same flow-volume curve during quiet breathing as they do during the forced expiratory vital capacity manoeuvre, and this has been taken as an indicator of expiratory flow limitation at rest (EFL(T)). Therefore, EFL(T), namely attainment of maximal expiratory flow during tidal expiration, occurs when an increase in transpulmonary pressure causes no increase in expiratory flow. EFL(T) leads to small airway injury and promotes dynamic pulmonary hyperinflation, with concurrent dyspnoea and exercise limitation. In fact, EFL(T) occurs commonly in COPD patients (mainly in Global Initiative for Chronic Obstructive Lung Disease III and IV stage), in whom the latter symptoms are common, but is not exclusive to COPD, since it can also be detected in other pulmonary and nonpulmonary diseases like asthma, acute respiratory distress syndrome, heart failure and obesity, etc. The existing up to date physiological techniques of assessing EFL(T) are reviewed in the present work. Among the currently available techniques, the negative expiratory pressure has been validated in a wide variety of settings and disorders. Consequently, it should be regarded as a simple, noninvasive, practical and accurate new technique.
患有严重慢性阻塞性肺疾病（COPD）的患者在平静呼吸时和用力呼气肺活量操作时往往沿着相同的流量-容积曲线呼气，这被视为休息时呼气流量受限（EFL(T)）的指标。因此，当跨肺压的增加不能引起呼气流量增加时，EFL(T)（即潮气量呼气时达到最大呼气流量）就会发生。EFL(T)导致小气道损伤并促进动态性肺过度充气，同时伴有呼吸困难和运动受限。事实上，EFL(T)在 COPD 患者中很常见（主要在全球倡议慢性阻塞性肺疾病 III 和 IV 期），后者的症状很常见，但并非 COPD 所特有，因为它也可以在其他肺部和非肺部疾病中检测到，如哮喘、急性呼吸窘迫综合征、心力衰竭和肥胖症等。本文综述了目前评估 EFL(T)的生理技术。在目前可用的技术中，负压已在广泛的环境和疾病中得到验证。因此，它应该被视为一种简单、无创、实用和准确的新技术。
