Open AccessThe effect of time-of-day and chest physiotherapy on multiple breath washout measures in children with clinically stable cystic fibrosis
Author(s) -
Christian Voldby,
Kent Green,
Susanne Rosthøj,
Thomas Kongstad,
L. Philipsen,
Frederik Buchvald,
Marianne Skov,
T. Pressler,
Per Gustafsson,
Kim G. Nielsen
Publication year - 2018
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0190894
Subject(s) - medicine , spirometry , cystic fibrosis , morning , confidence interval , chest physiotherapy , nitrogen washout , plethysmograph , physical therapy , washout , cardiology , anesthesia , lung volumes , asthma , lung , functional residual capacity
Background In this pilot study we investigated daytime variation of multiple breath nitrogen washout (N 2 MBW) measures in children with clinically stable cystic fibrosis. To our knowledge the effect of time-of-day on multiple breath washout measures in patients with cystic fibrosis has not previously been reported. Furthermore, we assessed the influence of chest physiotherapy on N 2 MBW measures. Methods Ten school children with cystic fibrosis performed N 2 MBW followed by spirometry and plethysmography in the morning and afternoon at three visits that were one month apart. Chest physiotherapy was performed immediately before the afternoon measurements at visit 2 and immediately before morning and afternoon measurements at visit 3. The influence of time-of-day and chest physiotherapy on the measures was evaluated using linear mixed models. Results There were adequate quality data from 8 children with median age (range) 9.6 (6.0; 15.1) years. Baseline lung clearance index (LCI) (range) was 9.0 (7.1; 13.0) and baseline FEV 1 % predicted was 97.5 (78.5; 117.9). No N 2 MBW measures were significantly influenced by time-of-day or chest physiotherapy. LCI (95% confidence interval) decreased non-significantly 0.05 (-0.32; 0.22) during the day and increased non-significantly 0.08 (-0.26; 0.42) after chest physiotherapy. All spirometric measures were unaffected by time-of-day and chest physiotherapy. For plethysmographic measures FRC pleth decreased significantly (p<0.01) 110 mL during the day, whereas a borderline significant (p = 0.046) decrease in ΔFRC pleth-MBW during the day and a borderline significant (p = 0.03) increase in TLC after CPT were observed. Conclusion This study demonstrated that the time-of-day as well as chest physiotherapy performed immediately prior to N 2 MBW had no consistent or significant influence on N 2 MBW measures. However, we emphasize that further studies of the effect of both daytime variation and the effect of chest physiotherapy on multiple breath washout measures are warranted.