In:
European Respiratory Journal, European Respiratory Society (ERS), Vol. 45, No. 3 ( 2015-03), p. 625-634
Abstract:
The forced oscillation technique can identify expiratory flow limitation (EFL) when a large difference in inspiratory and expiratory reactance (Δ X rs ) occurs. However, flow limitation can vary from breath to breath, and so we compared a multiple-breath Δ X rs approach to the traditional breath-by-breath assessment of EFL. We investigated the within- and between-day reproducibility and the factors that affect the size of Δ X rs when used as a continuous measurement over multiple breaths. In addition, we examined how multiple-breath Δ X rs relates to the sensation of breathlessness. 425 moderate to very severe chronic obstructive pulmonary disease (COPD) patients and 229 controls were included. Spirometry and impedance measurements were performed on a MasterScope CT Impulse Oscillation System. Median Δ X rs approached zero in healthy controls with little variation between measurements. COPD patients generally had higher Δ X rs and higher variability. The COPD patients with Δ X rs 〉 0.1 kPa·L −1 ·s −1 were prone to be more breathless and had a higher modified Medical Research Council dyspnoea scale score. In controls, the 95th percentile of Δ X rs was as low as 0.07 kPa·L −1 ·s −1 . We describe a new method to assess EFL at a patient level and propose a cut-off, mean Δ X rs 〉 0.1 kPa·L −1 ·s −1 , as a way to identify COPD patients who are more likely to report dyspnoea.
Type of Medium:
Online Resource
ISSN:
0903-1936
,
1399-3003
DOI:
10.1183/09031936.00051214
Language:
English
Publisher:
European Respiratory Society (ERS)
Publication Date:
2015
detail.hit.zdb_id:
2834928-3
detail.hit.zdb_id:
1499101-9
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