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Evaluation of impulse oscillometry during bronchial challenge testing in children
Author(s) -
Bailly Carole,
Crenesse Dominique,
Albertini Marc
Publication year - 2011
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/ppul.21492
Subject(s) - medicine , methacholine , spirometry , asthma , receiver operating characteristic , gold standard (test) , respiratory system , cardiology , respiratory disease , lung
Background The impulse oscillation system (IOS) allows easy measurement of respiratory system impedance (Zrs). The aim of this retrospective study was to evaluate the accuracy of IOS parameters obtained during methacholine challenge by comparison with “the gold standard” forced expiratory volume in the first second (FEV 1 ). Methods Measurements of FEV 1 and resistances at 5 and 20 Hz, reactance at 5 Hz, impedance at 5 Hz and resonant frequency were performed in 227 children with suspected asthma, before and during methacholine challenge. Data were analyzed in the overall population and in three subgroups according to the final diagnosis: asthma (n = 72), chronic cough and nonspecific respiratory symptoms (n = 122), allergic rhinitis (n = 33). Results All IOS parameters changed significantly during the tests but only changes in X5 were significantly different between responders and nonresponders. Moreover, changes in IOS parameters were not correlated with changes in FEV 1 apart from a weak correlation for X5. The receiver operating characteristic (ROC) curve for changes in X5 (to predict a 20% decrease in FEV 1 ) showed a best decision level for a 50% decrease in X5 with a sensitivity of 36% and a specificity of 85%. Results were not different in the asthma group. Conclusion The accuracy of measurements by IOS during methacholine bronchial challenge in children was not suitable when compared with FEV 1 . It could be assumed that spirometry and IOS, while both providing indirect indices of airway patency, are exploring different mechanisms, each with its own methodological potentials and limitations. Pediatr Pulmonol. 2011; 46: 1209–1214. © 2011 Wiley Periodicals, Inc.