Investigation of shortened lung clearance index (LCI) in the Bronch-UK Clinimetrics study.
Bronchiectasis, Lung function testing
K. O'Neill1, G. R. Lakshmipathy1, C. Neely1, D. Cosgrove2, K. Ferguson2, J. D. Chalmers3, A. Desoyza4, T. Gatheral5, A. T. Hill6, J. R. Hurst7, M. R. Loebinger8, J. S. Elborn9, J. M. Bradley101Wellcome-Wolfson Institute for Experimental Medicine, Queen's University - Belfast (United Kingdom), 2Belfast Health and Social Care Trust - Belfast (United Kingdom), 3University of Dundee, College of Medicine - Dundee (United Kingdom), 4Institute of Cellular Medicine, Newcastle University, National Institute of Health Research Biomedical Research Centre - Newcastle (United Kingdom), 5Department of Respiratory Medicine, University Hospitals of Morecambe Bay NHS Foundation Trust - Kendal (United Kingdom), 6Royal Infirmary and University of Edinburgh - Edinburgh (United Kingdom), 7University College London Respiratory, University College London - London (United Kingdom), 8Host Defence Unit, Royal Brompton Hospital, Imperial College London - London (United Kingdom), 9Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast; Host Defence Unit, Royal Brompton Hospital, Imperial College London - London (United Kingdom), 10Clinical Research Facility, Queen’s University - Belfast (United Kingdom)
Background: LCI has good intravisit repeatability with better sensitivity in detecting lung disease on CT scan compared to FEV1 in adults with bronchiectasis (BE) (Rowan et al. 2014). However, the test can be prolonged. Shortened LCI may provide sufficient information on ventilation distribution and reduce test time.Aim:To compare the intravisit repeatability (CV%) of LCI2.5 (standard LCI) and LCI5 (shortened LCI) relationship between FEV1% predicted and LCI2.5 and LCI5.time duration of the triplicate washout for LCI2.5 and LCI5.
Methods: Multiple Breath Nitrogen Washout data (Exhalyzer D) from the first 98 patients across 5 UK centres (November 2015- June 2017) were over-read centrally for quality control. LCI2.5 (LCI at 2.5% N2) and LCI5 (LCI at 5% N2) data were summarised. CV% and duration of tests (minutes) were compared using paired sample t–tests. Pearson correlation were used to assess relationships.Results: Subjects (n=98), M:F 37:61, had a mean age (SD) 64.8 (11.6) years, FEV1% predicted=74.7 (20.9), LCI2.5 =12.6 (3.2) turnovers, LCI5=7.8 (1.6) turnovers. Mean (SD) CV% of LCI2.5 and LCI5 was 3.8 (2.1) and 2.9 (1.8) respectively (p=0.03). Mean (SD) duration (minutes) of LCI .5 and LCI5 washout time was 15.2 (7.8) and 7.8 (3.6) respectively (p<0.001). The correlation (r and p-value) between FEV1% predicted and LCI2.5 and LCI5 was r=-0.56 (p<0.001) and r=-0.56 (p<0.001) respectively.
Conclusions: In this study, LCI5 had reduced variability (CV%), a comparable strength of correlation with FEV1% predicted and a significant time saving compared with LCI2.5. Investigation of LCI5 in BE clinical trials as a surrogate outcome is warranted.
|Number of pages||2|
|Publication status||Accepted - 05 Jun 2018|
|Event||European Respiratory Society International Congress 2018: Paris, 2018 - Paris, France, Paris, France|
Duration: 15 Sep 2018 → 19 Sep 2018
|Conference||European Respiratory Society International Congress 2018|
|Period||15/09/2018 → 19/09/2018|