Browsing by Author "Ramsey, Kathryn A."

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    The clinical utility of lung clearance index in early cystic fibrosis lung disease is not impacted by the number of multiple-breath washout trials
    (European Respiratory Society, 2018-02-16) Foong, Rachel E.; Harper, Alana J.; Skoric, Billy; King, Louise; Turkovic, Lidija; Davis, Miriam; Clem, Charles C.; Rosenow, Tim; Davis, Stephanie D.; Ranganathan, Sarath; Hall, Graham L.; Ramsey, Kathryn A.; Pediatrics, School of Medicine
    The lung clearance index (LCI) from the multiple-breath washout (MBW) test is a promising surveillance tool for pre-school children with cystic fibrosis (CF). Current guidelines for MBW testing recommend that three acceptable trials are required. However, success rates to achieve these criteria are low in children aged <7 years and feasibility may improve with modified pre-school criteria that accepts tests with two acceptable trials. This study aimed to determine if relationships between LCI and clinical outcomes of CF lung disease differ when only two acceptable MBW trials are assessed. Healthy children and children with CF aged 3-6 years were recruited for MBW testing. Children with CF also underwent bronchoalveolar lavage fluid collection and a chest computed tomography scan. MBW feasibility increased from 46% to 75% when tests with two trials were deemed acceptable compared with tests where three acceptable trials were required. Relationships between MBW outcomes and markers of pulmonary inflammation, infection and structural lung disease were not different between tests with three acceptable trials compared with tests with two acceptable trials. This study indicates that pre-school MBW data from two acceptable trials may provide sufficient information on ventilation distribution if three acceptable trials are not possible.
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    Multiple-Breath Washout Outcomes Are Sensitive to Inflammation and Infection in Children with Cystic Fibrosis
    (ATS, 2017-09) Ramsey, Kathryn A.; Foong, Rachel E.; Grdosic, Jasmine; Harper, Alana; Skoric, Billy; Clem, Charles; Davis, Miriam; Turkovic, Lidija; Stick, Stephen M.; Davis, Stephanie D.; Ranganathan, Sarath C.; Hall, Graham L.; Pediatrics, School of Medicine
    Rationale: The lung clearance index is a measure of ventilation distribution derived from the multiple-breath washout technique. The lung clearance index is increased in the presence of lower respiratory tract inflammation and infection in infants with cystic fibrosis; however, the associations during the preschool years are unknown. Objectives: We assessed the ability of the lung clearance index to detect the presence and extent of lower respiratory tract inflammation and infection in preschool children with cystic fibrosis. Methods: Ventilation distribution outcomes were assessed at 82 visits with 58 children with cystic fibrosis and at 38 visits with 31 healthy children aged 3–6 years. Children with cystic fibrosis also underwent bronchoalveolar lavage fluid collection for detection of lower respiratory tract inflammation and infection. Associations between multiple-breath washout indices and the presence and extent of airway inflammation and infection were assessed using linear mixed effects models. Results: Lung clearance index was elevated in children with cystic fibrosis (mean [SD], 8.00 [1.45]) compared with healthy control subjects (6.67 [0.56]). In cystic fibrosis, the lung clearance index was elevated in individuals with lower respiratory tract infections (difference compared with uninfected [95% confidence interval], 0.62 [0.06, 1.18]) and correlated with the extent of airway inflammation. Conclusions: These data suggest that the lung clearance index may be a useful surveillance tool for monitoring the presence and extent of lower airway inflammation and infection in preschool children with cystic fibrosis.