Browsing by Subject "multiple breath washout"

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    Inter-test reproducibility of the lung clearance index measured by multiple breath washout
    (ERS, 2017-10-01) Engberink, Esther Oude; Ratjen, Felix; Davis, Stephanie D.; Retsch-Bogart, George; Amin, Reshma; Stanojevic, Sanja; Pediatrics, School of Medicine
    The lung clearance index (LCI) has strong intra-test repeatability; however, the inter-test reproducibility of the LCI is poorly defined. The aim of the present study was to define a physiologically meaningful change in LCI in preschool children, which discriminates changes associated with disease progression from biological variability. Repeated LCI measurements from a longitudinal cohort study of children with cystic fibrosis and age-matched controls were collected to define the inter-visit reproducibility of the LCI. Absolute change, the coefficient of variation, Bland–Altman limits of agreement, the coefficient of repeatability, intra-class correlation coefficient, and percentage changes were calculated. LCI measurements (n=505) from 71 healthy and 77 cystic fibrosis participants (aged 2.6–6 years) were analysed. LCI variability was proportional to its magnitude, such that reproducibility defined by absolute changes is biased. A physiologically relevant change for quarterly LCI measurements in health was defined as exceeding ±15%. In clinically stable cystic fibrosis participants, the threshold was higher (±25%); however, for measurements made 24 h apart, the threshold was similar to that observed in health (±17%). A percentage change in LCI greater than ±15% in preschool children can be considered physiologically relevant and greater than the biological variability of the test. Biological variability of lung clearance index is dependent on magnitude; % change is better for tracking patients http://ow.ly/tgbX30dBbCX
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    Lung Clearance Index to Track Acute Respiratory Events in School-Age Children with Cystic Fibrosis
    (ATS, 2021-04) Perrem, Lucy; Stanojevic, Sanja; Shaw, Michelle; Jensen, Renee; McDonald, Nancy; Isaac, Sarah M.; Davis, Miriam; Clem, Charles; Guido, Julia; Jara, Sylvia; France, Lisa; Soloman, Melinda; Grasemann, Hartmut; Waters, Valerie; Sweezey, Neil; Sanders, Don B.; Davis, Stephanie D.; Ratjen, Felix; Pediatrics, School of Medicine
    Rationale: The lung clearance index (LCI) is responsive to acute respiratory events in preschool children with cystic fibrosis (CF), but its utility to identify and manage these events in school-age children with CF is not well defined. Objectives: To describe changes in LCI with acute respiratory events in school-age children with CF. Methods: In a multisite prospective observational study, the LCI and FEV1 were measured quarterly and during acute respiratory events. Linear regression was used to compare relative changes in LCI and FEV1% predicted at acute respiratory events. Logistic regression was used to compare the odds of a significant worsening in LCI and FEV1% predicted at acute respiratory events. Generalized estimating equation models were used to account for repeated events in the same subject. Measurements and Main Results: A total of 98 children with CF were followed for 2 years. There were 265 acute respiratory events. Relative to a stable baseline measure, LCI (+8.9%; 95% confidence interval, 6.5 to 11.3) and FEV1% predicted (−6.6%; 95% confidence interval, −8.3 to −5.0) worsened with acute respiratory events. A greater proportion of events had a worsening in LCI compared with a decline in FEV1% predicted (41.7% vs. 30.0%; P = 0.012); 53.9% of events were associated with worsening in LCI or FEV1. Neither LCI nor FEV1 recovered to baseline values at the next follow-up visit. Conclusions: In school-age children with CF, the LCI is a sensitive measure to assess lung function worsening with acute respiratory events and incomplete recovery at follow-up. In combination, the LCI and FEV1 capture a higher proportion of events with functional impairment.
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    Pediatric pulmonology year in review 2020: Physiology
    (Wiley, 2021-08) Delecaris, Angela O.; Averill, Samantha H.; Krasinkiewicz, Jonathan; Saunders, Jessica L.; Ren, Clement L.; Pediatrics, School of Medicine
    Pulmonary physiology is a core element of pediatric pulmonology care and research. This article reviews some of the notable publications in physiology that were published in Pediatric Pulmonology in 2020.