The role of the FEF50%/0.5FVC ratio in the diagnosis of obstructive lung diseases.
The role of the FEF50%/0.5FVC ratio in the diagnosis of obstructive lung diseases.
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DOI：
10.1590/s1806-37132010000100009
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
M. T. Rodrigues;Daniel Fiterman-Molinari;S. Barreto;J. Fiterman
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文献类型：
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作者：
M. T. Rodrigues;Daniel Fiterman-Molinari;S. Barreto;J. Fiterman
目的 评估从最大呼气流量-容积曲线获得的新系数 FEF50%/0.5FVC 比值对阻塞性肺疾病 (OLD) 诊断的贡献；测试该系数以区分正常患者、OLD 患者和限制性肺病 (RLD) 患者；并确定每个功能诊断的分界点，以及基于个体值的每个诊断的概率。方法 一项前瞻性横断面研究分析了 2003 年 1 月至 12 月转诊至巴西阿雷格里港阿雷格里港医院诊所的患者的肺功能。我们收集了人口统计和肺活量数据。患者被分为三组：正常组；老的;和RLD。我们计算了 FEV1/FVC 和 FEF50%/0.5FVC 比率，并比较了各组之间的平均 FEF50%/0.5FVC 值。我们使用 Pearson 相关性检验来比较 FEF50%/0.5FVC 与 FEV1/FVC。患者再次分为两组：患有 OLD 的组和没有 OLD 的组。我们计算了不同截止点的似然比。结果 患者的平均年龄为 55.8 +/- 14.7 岁。各组之间的平均 FEF50%/0.5FVC 存在显着差异（正常、RLD 和 OLD 分别为 2.10 +/- 0.82、2.55 +/- 1.47 和 0.56 +/- 0.29；p 1.33 实际上排除了这一诊断。结论 FEF50%/0.5FVC 比值是鉴别诊断 OLD 和 OLD 的潜在有用参数。与 FEV1/FVC 比率呈正相关。
OBJECTIVE To evaluate the contribution of a new coefficient, the FEF50%/0.5FVC ratio, obtained from the maximal expiratory flow-volume curve, to the diagnosis of obstructive lung disease (OLD); to test this coefficient in differentiating among patients considered normal, those with OLD and those with restrictive lung disease (RLD); and to determine cut-off points for each functional diagnosis, as well as the probability for each diagnosis based on individual values. METHODS A prospective, cross-sectional study analyzing the pulmonary function of patients referred to the Porto Alegre Hospital de Clínicas, in Porto Alegre, Brazil, between January and December of 2003. We collected demographic and spirometric data. The patients were divided into three groups: normal; OLD; and RLD. We calculated the FEV1/FVC and FEF50%/0.5FVC ratios, and we compared the mean FEF50%/0.5FVC values among the groups. We used Pearson's correlation test in order to compare FEF50%/0.5FVC with FEV1/FVC. The patients were again divided into two groups: those with OLD and those without OLD. We calculated the likelihood ratio for different cut-off points. RESULTS The mean age of the patients was 55.8 +/- 14.7 years. There were significant differences among the groups in terms of the mean FEF50%/0.5FVC (2.10 +/- 0.82, 2.55 +/- 1.47 and 0.56 +/- 0.29, respectively, for normal, RLD and OLD; p 1.33 practically excludes this diagnosis. CONCLUSIONS The FEF50%/0.5FVC ratio is a potentially useful parameter in the differential diagnosis of OLD and correlates positively with the FEV1/FVC ratio.