We read with interest the recent letter by Johansson et al. [1], investigating bronchodilator responses in respiratory oscillometry using a commercial, widely used impulse oscillometry (IOS) device. The authors defined the limits of what constitutes a normal bronchodilator response, based on a large dataset of 1495 healthy non-smokers from a Swedish population-based study. From this, they determined the cut-offs for respiratory system resistance and reactance at 5 Hz (Rrs₅ and Xrs₅, respectively) to be –28.9% and 44.9%, respectively, derived from the limits of normal, i.e. 95th/5th centile of the bronchodilator responses of this reference population. The authors noted that these cut-offs are smaller than those recommended in the recent European Respiratory Society technical standards [2]. However, they are similar to the multi-device values observed in 368 healthy adults by Oostveen et al. [3], who reported –31.5% and –31.6% for Rrs₅ and Rrs₆, and 43.5% and 67.8% for Xrs₅ and Xrs₆, respectively. The latter might not be surprising given that the IOS device was among the devices included in the study reported by Oostveen et al. [3].

我们感兴趣地阅读了 J 最近的来信欧汉松 等人。[1]，使用商用、广泛使用的脉冲示波法 (IOS) 设备研究呼吸示波法中的支气管扩张剂反应。作者根据瑞典一项基于人群的研究的 1495 名健康非吸烟者的大型数据集，定义了构成正常支气管扩张剂反应的限制。由此，他们确定了呼吸系统阻力和电抗在 5 Hz 时的截止值（分别为R rs ₅和X rs ₅）分别为 –28.9% 和 44.9%，来自正常限值，即该参考人群的支气管扩张剂反应的第 95/5 个百分位数。作者指出，这些截止值小于最近欧洲呼吸学会技术标准中推荐的值 [2]。然而，它们与 O 在 368 名健康成年人中观察到的多设备值相似东文 等人。[3]，他们报告R rs ₅和R rs ₆分别为 –31.5% 和 –31.6% ， X rs ₅和X rs ₆分别为 43.5% 和 67.8% 。鉴于 IOS 设备是 O 报告的研究中包括的设备之一，后者可能并不令人惊讶东文 等人。[3]。