The validity of shortened multiple-breath washout testing using sulfur hexafluoride in the assessment of patients with COPD.

Autor: Daynes E; Centre of Exercise and Rehabilitation Sciences, NIHR Leicester Biomedical Research Centre - Respiratory, Leicester, UK., Greening N; Centre of Exercise and Rehabilitation Sciences, NIHR Leicester Biomedical Research Centre - Respiratory, Leicester, UK., Owers-Bradley J; School of Physics and Astronomy, University of Nottingham, Nottingham, UK., Singh SJ; Centre of Exercise and Rehabilitation Sciences, NIHR Leicester Biomedical Research Centre - Respiratory, Leicester, UK., Siddiqui S; NIHR Leicester Biomedical Research Centre - Respiratory, Leicester, UK.
Jazyk: angličtina
Zdroj: ERJ open research [ERJ Open Res] 2021 Aug 02; Vol. 7 (3). Date of Electronic Publication: 2021 Aug 02 (Print Publication: 2021).
DOI: 10.1183/23120541.00379-2020
Abstrakt: Introduction: COPD affects the small airways and is associated with ventilation heterogeneity. There are little data on the multiple-breath washout (MBW) in patients with COPD, particularly the variability over 8 weeks, using a shortened sulfur hexafluoride (SF 6 ) washout. This work evaluated the repeatability of the lung clearance index (LCI) 1/40 and LCI 1/20 among subjects with COPD and compared to spirometry and clinical markers.
Methods: The MBW was performed on patients with COPD to determine ventilation heterogeneity globally (LCI), at conductive (S cond ) and acinar (S acin ) levels. The LCI was repeated in triplicate and measured at a traditional 1/40th washout and retrofitted to a shortened 1/20th end tidal SF 6 concentration washout. Tests were repeated after 20 min and 8  weeks to determine within and between visit repeatability and compared with spirometry.
Results: Eighty-four subjects were recruited to perform LCI and spirometry with 20 subjects performing the repeatability protocol. There were weak correlations between forced expiratory volume in 1 s ( FEV 1 ) per cent predicted and LCI 1/40th r=-0.311 (p=0.02), and LCI 1/20th r=-0.40 (p<0.01). The LCI demonstrated excellent within and good between visit repeatability for both a 1/40th and 1/20th washout (intraclass correlation coefficient (ICC)≥0.80). There was a statistically significant strong correlation between LCI 1/40th and a shortened LCI 1/20 of 0.86 (p<0.01).
Conclusions: The LCI is repeatable within and between visits. There are weak correlations with measures of spirometry. A shortened LCI 1/20th starting concentration correlates highly with a 1/40th washout, which may encourage clinical use.
Competing Interests: Conflict of interest: E. Daynes reports that Actegy Ltd funds a commercial trial from which the present data were obtained. Conflict of interest: N. Greening has nothing to disclose. Conflict of interest: J. Owers-Bradley has nothing to disclose. Conflict of interest: S. Singh reports that Actegy Ltd funds a commercial trial from which the present data were obtained. Conflict of interest: S. Siddiqui reports advisory boards for and speaker fees from AstraZeneca, GSK, Novartis, Roche, Boehringer Ingelheim, Owlstone Medical, Mundipharma and ERT Medical, outside the submitted work.
(Copyright ©The authors 2021.)
Databáze: MEDLINE
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