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BioMed Research International
Volume 2017 (2017), Article ID 9460190, 9 pages
https://doi.org/10.1155/2017/9460190
Research Article

Clinical Implications of Oscillatory Lung Function during Methacholine Bronchoprovocation Testing of Preschool Children

1Department of Pediatrics, Kyung Hee University School of Medicine, Seoul, Republic of Korea
2Department of Pediatrics, CHA University School of Medicine, Seoul, Republic of Korea
3Department of Medicines, CHA University School of Medicine, Seongnam, Republic of Korea
4Department of Pediatrics, Dongtan Sacred Heart Hospital, College of Medicine, Hallym University, Hwaseong, Republic of Korea
5Department of Pediatrics, Kangdong Sacred Heart Hospital, Hallym University, Seoul, Republic of Korea
6Department of Pediatrics, Myongji Hospital, Seonam University College of Medicine, Goyang, Republic of Korea

Correspondence should be addressed to Man Yong Han; moc.liamg@hsemrd

Received 11 February 2017; Revised 21 April 2017; Accepted 7 May 2017; Published 27 June 2017

Academic Editor: Hiroshi Tanaka

Copyright © 2017 Sun Hee Choi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objective. To investigate the repeatability and safety of measuring impulse oscillation system (IOS) parameters and the point of wheezing during bronchoprovocation testing of preschool children. Methods. Two sets of methacholine challenge were conducted in 36 asthma children. The test was discontinued if there was a significant change in reactance (Xrs5) and resistance (Rrs5) at 5 Hz (Condition 1) or respiratory distress due to airway obstruction (Condition 2). The repeatability of PC80_Xrs5, PC30_Rrs5, and wheezing (PCw) was assessed. The changes in -scores and SD-indexes from prebaseline (before testing) to postbaseline (after bronchodilator) were determined. Results. For PC30_Rrs5, PC80_Xrs5, and PCw for subjects, PC80_Xrs5 showed the highest repeatability. Fifteen of 70 tests met Condition . The changes from pre- and postbaseline values varied significantly for Rrs5 and Xrs5. Excluding subjects with -scores higher than 2SD, we were able to detect 97.1% of bronchial hyperresponsiveness during methacholine challenge based on the change in Rrs5 or Xrs5. A change in IOS parameters was associated with wheezing at all frequencies. Conclusion. Xrs5 and Rrs5 have repeatability comparable with FEV1, and Xrs5 is more reliable than Rrs5. Clinicians can safely perform a challenge test by measuring the changes in Rrs5, Xrs5, and -scores from the prebaseline values.