We used the Impulse Oscillometric System (IOS) to gain information concerning the distribution of hyper-reactivity along the bronchial tree during methacholine challenge test (MCT).37 subjects underwent MCT until reaching the provocative dose (PD20). At each dose, we estimated respiratory resistance at 5 and 20Hz (R5, R20), and reactance at 5Hz (X5). In non-responsive subjects (N=14) no changes in R5, R20, and X5 were observed during MCT. In responsive subjects, a wide spectrum of responses was found concerning frequency dependence and PD20. We describe two phenotypes representing the extremes of response. For PD20>400μg (N=13), MCT caused equal changes of resistance/reactance on varying oscillation frequencies, suggesting a homogeneous bronchoconstriction along the bronchial tree. For PD20<200μg (N=10), a remarkable frequency dependence was observed, with increase in R5, no change in R20, and decrease in X5, suggesting hyper-responsiveness of the distal airways paralleled by a change in visco-elastic properties of lung parenchyma. © 2013 Elsevier B.V.

Beretta, A., Tana, F., Grasso, G., Bartesaghi, M., Novelli, L., Pesci, A., et al. (2014). Regional differences in bronchial reactivity assessed by respiratory impedance. RESPIRATORY PHYSIOLOGY & NEUROBIOLOGY, 192, 23-29 [10.1016/j.resp.2013.12.002].

Regional differences in bronchial reactivity assessed by respiratory impedance

Novelli, L;PESCI, ALBERTO;MISEROCCHI, GIUSEPPE ANDREA
2014

Abstract

We used the Impulse Oscillometric System (IOS) to gain information concerning the distribution of hyper-reactivity along the bronchial tree during methacholine challenge test (MCT).37 subjects underwent MCT until reaching the provocative dose (PD20). At each dose, we estimated respiratory resistance at 5 and 20Hz (R5, R20), and reactance at 5Hz (X5). In non-responsive subjects (N=14) no changes in R5, R20, and X5 were observed during MCT. In responsive subjects, a wide spectrum of responses was found concerning frequency dependence and PD20. We describe two phenotypes representing the extremes of response. For PD20>400μg (N=13), MCT caused equal changes of resistance/reactance on varying oscillation frequencies, suggesting a homogeneous bronchoconstriction along the bronchial tree. For PD20<200μg (N=10), a remarkable frequency dependence was observed, with increase in R5, no change in R20, and decrease in X5, suggesting hyper-responsiveness of the distal airways paralleled by a change in visco-elastic properties of lung parenchyma. © 2013 Elsevier B.V.
Articolo in rivista - Articolo scientifico
respiratory resistance, asthma, small airways, respiratory reactance
English
2014
192
23
29
none
Beretta, A., Tana, F., Grasso, G., Bartesaghi, M., Novelli, L., Pesci, A., et al. (2014). Regional differences in bronchial reactivity assessed by respiratory impedance. RESPIRATORY PHYSIOLOGY & NEUROBIOLOGY, 192, 23-29 [10.1016/j.resp.2013.12.002].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/51332
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