Coates A L, Desmond K J, Demizio D, Allen P D
Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Canada.
Am J Respir Crit Care Med. 1994 Feb;149(2 Pt 1):439-43. doi: 10.1164/ajrccm.149.2.8306042.
The American Thoracic Society (ATS) recommendations to establish reproducibility of the forced expiratory volume in one second (FEV1) are that the value come from "at least 3 acceptable forced expiratory curves" where "the largest forced vital capacity maneuver (FVC) and the second largest FVC should not vary by more than 5%." It has been suggested that there is a "negative effort dependence" of the FEV1 and, alternatively, that the magnitude of the FVC influences the FEV1. We examined the relationship between FEV1 and a direct measurement of effort, or work, defined as the area under the alveolar pressure-volume curve in 1 s. Thirteen normal individuals and 17 patients with cystic fibrosis or asthma were instructed to make a series of maximal efforts, as in routine testing. Comparing the maneuver that resulted in the greatest work to that with the lowest work, all with FVCs within 5% of one another, there was no correlation between change in work and change in FEV1 (delta FEV1). There was a significant relationship between delta FEV1 and changes in FVC (r = 0.49, p < 0.01). The delta FEV1 did not correlate with the degree of hyperinflation (the FRC) or degree of airflow limitation (the initial FEV1). The magnitude of changes in FEV1 was small and almost always within acceptable limits for reproducibility. Because a larger FVC is due either to an increased inspiration, which could affect the FEV1, or to an increased expiratory reserve volume, which occurs only after the first second, these results emphasize the importance of a maximal inspiration at the start of the test.
美国胸科学会（ATS）关于建立一秒用力呼气容积（FEV1）可重复性的建议是，该值应来自“至少3条可接受的用力呼气曲线”，其中“最大用力肺活量动作（FVC）和第二大FVC的差异不应超过5%”。有人提出FEV1存在“负努力依赖性”，或者说FVC的大小会影响FEV1。我们研究了FEV1与直接测量的努力程度（即功）之间的关系，功定义为1秒内肺泡压力-容积曲线下的面积。13名正常人和17名囊性纤维化或哮喘患者被要求像常规测试那样进行一系列最大努力。将产生最大功的动作与最小功的动作进行比较，所有FVC彼此相差不超过5%，功的变化与FEV1的变化（ΔFEV1）之间没有相关性。ΔFEV1与FVC的变化之间存在显著关系（r = 0.49，p < 0.01）。ΔFEV1与肺过度充气程度（功能残气量）或气流受限程度（初始FEV1）无关。FEV1变化的幅度很小，几乎总是在可重复性的可接受范围内。由于较大的FVC要么是由于吸气增加（这可能会影响FEV1），要么是由于呼气储备量增加（这仅在第一秒之后出现），这些结果强调了在测试开始时进行最大吸气的重要性。
