Extract
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].
Abstract
Bronchodilator response cut-offs from oscillometry are robust across devices, and should be separated for adults (Rrs5 −32% and Xrs5 44%) and children (Rrs5 −40% and Xrs5 50%). Absolute and Z-score cut-offs should also be considered. https://bit.ly/3FcjDfK
Footnotes
Conflict of interest: C. Thamrin reports intellectual property arrangements/contracts from Restech SRL, Milan, Italy; equipment on loan for research studies from Restech SRL, Milan, Italy and THORASYS Thoracic Medical Systems, Montreal, Canada; outside the submitted work. G.G. King reports grants, personal fees and other from AstraZeneca, Boehringer Ingelheim, GlaxoSmithKline, Novartis, Menarini, MundiPharma, grants from National Health and Medical Research Council, Professional Societies, The University of Sydney, and philanthropic individuals and societies, outside the submitted work. All other authors have nothing to disclose.
- Received October 8, 2021.
- Accepted December 21, 2021.
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