La Berma Clinic, Assistance Publique-Hôpitaux de Paris; Georges Pompidou European Hospital, Paris, France.
Respirology. 2011 May;16(4):666-71. doi: 10.1111/j.1440-1843.2011.01953.x.
Changes in specific airway resistance (ΔsRaw) after bronchodilation, as measured by plethysmography and FEV(1) , are frequently considered to be interchangeable indices of airway obstruction. However, the baseline relationship between these two indices is weak, and the value of ΔsRaw that best predicts FEV(1) reversibility in children has yet to be determined. The aim of this study was (i) to establish the sRaw cut-off value that best distinguishes between positive and negative bronchodilator responses, as measured by FEV(1) reversibility; (ii) to determine whether the discrepancy between ΔsRaw and ΔFEV(1) might be explained by independent correlations between ΔFEV(1) and both ΔsRaw (mainly airway obstruction) and ΔFVC (airway closure); and (iii) to assess the effect of height and age on the relationship between ΔsRaw and ΔFEV(1) .
A retrospective study was performed in 481 children (median age 10.5years, range 6.1-17.6) with actual or suspected asthma, for whom sRaw and spirometry data were obtained at baseline and after administration of a bronchodilator.
The sRaw cut-off value that best predicted FEV(1) reversibility was a 42% decrease from baseline (P=0.0001, area under the curve 0.70, sensitivity 55%, specificity 77%) and was independent of height and age. Changes in FEV(1) were significantly but independently related to ΔsRaw and ΔFVC (index of air trapping) (r=0.40, P<0.0001 and r=0.39, P<0.0001, respectively).
A 42% decrease in sRaw predicted FEV(1) reversibility reasonably well, whereas a smaller decrease in sRaw failed to detect approximately one out of two positive responses detected by FEV(1) , with no influence of height or age.
通过体描法和 FEV1 测量得出的气道阻力特定变化（ΔsRaw），通常被认为是气道阻塞的可互换指标。然而，这两个指标之间的基线关系较弱，并且尚未确定预测儿童 FEV1 可逆性的最佳 ΔsRaw 值。本研究旨在：（i）确定区分 FEV1 可逆性阳性和阴性的最佳 sRaw 截断值；（ii）确定 ΔsRaw 与 ΔFEV1 之间的差异是否可以通过 ΔFEV1 与 ΔsRaw（主要是气道阻塞）和 ΔFVC（气道关闭）之间的独立相关性来解释；以及（iii）评估身高和年龄对 ΔsRaw 和 ΔFEV1 之间关系的影响。
对 481 名（中位年龄 10.5 岁，范围 6.1-17.6 岁）疑似或确诊哮喘的儿童进行回顾性研究，这些儿童在基础状态和支气管扩张剂治疗后均获得了 sRaw 和肺功能检查数据。
预测 FEV1 可逆性的最佳 sRaw 截断值为基线下降 42%（P=0.0001，曲线下面积 0.70，敏感性 55%，特异性 77%），与身高和年龄无关。FEV1 的变化与 ΔsRaw 和 ΔFVC（空气潴留指标）显著但独立相关（r=0.40，P<0.0001 和 r=0.39，P<0.0001）。
sRaw 下降 42%可较好地预测 FEV1 可逆性，而 sRaw 下降较小则无法检测到约一半由 FEV1 检测到的阳性反应，且不受身高或年龄的影响。
