sly-airwaydynamics-2017.pdf (807.15 kB)
Airway dynamics in COPD patients by within-breath impedance tracking: Effects of continuous positive airway pressure
journal contribution
posted on 2017-02-01, 00:00 authored by A Lorx, D Czövek, Z Gingl, G Makan, B Radics, D Bartusek, S Szigeti, J Gál, G Losonczy, Peter Sly, Z HantosTracking of the within-breath changes of respiratory mechanics using the forced oscillation technique may provide outcomes that characterise the dynamic behaviour of the airways during normal breathing.We measured respiratory resistance (Rrs) and reactance (Xrs) at 8 Hz in 55 chronic obstructive pulmonary disease (COPD) patients and 20 healthy controls, and evaluated Rrs and Xrs as functions of gas flow (V′) and volume (V) during normal breathing cycles. In 12 COPD patients, additional measurements were made at continuous positive airway pressure (CPAP) levels of 4, 8, 14 and 20 hPa.The Rrs and Xrsversus V′ and V relationships displayed a variety of loop patterns, allowing characterisation of physiological and pathological processes. The main outcomes emerging from the within-breath analysis were the Xrsversus V loop area (AXV) quantifying expiratory flow limitation, and the tidal change in Xrs during inspiration (ΔXI) reflecting alteration in lung inhomogeneity in COPD. With increasing CPAP, AXV and ΔXI approached the normal ranges, although with a large variability between individuals, whereas mean Rrs remained unchanged.Within-breath tracking of Rrs and Xrs allows an improved assessment of expiratory flow limitation and functional inhomogeneity in COPD; thereby it may help identify the physiological phenotypes of COPD and determine the optimal level of respiratory support.
History
Journal
European Respiratory JournalVolume
49Issue
2Article number
1601270Pagination
1 - 11Publisher
European Respiratory Society (ERS)Location
Sheffield, Eng.Publisher DOI
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ISSN
0903-1936eISSN
1399-3003Language
engPublication classification
C1 Refereed article in a scholarly journalUsage metrics
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