Impact of lung disease on respiratory impedance in young children with cystic fibrosis

Abstract

This study aimed to evaluate the ability of the forced oscillation technique (FOT) to detect underlying lung disease in preschool children with cystic fibrosis (CF) diagnosed following newborn screening.184 children (aged 3-6 years) with CF underwent lung function testing on 422 occasions using the FOT to assess respiratory resistance and reactance at the time of their annual bronchoalveolar lavage collection and chest computed tomography scan. We examined associations between FOT outcomes and the presence and progression of respiratory inflammation, infection and structural lung disease.Children with CF who had pronounced respiratory disease, including free neutrophil elastase activity, infection with pro-inflammatory pathogens and structural lung abnormalities had similar FOT outcomes to those children without detectable lung disease. In addition, the progression of lung disease over 1 year was not associated with worsening FOT outcomes.We conclude that the forced oscillation technique is relatively insensitive to detect underlying lung disease in preschool children with CF. However, FOT may still be of value in improving our understanding of the physiological changes associated with early CF lung disease. @ERSpublications Forced oscillation technique is insensitive in detecting lung disease in preschool children with cystic fibrosis http://ow.ly/R9rSU

Identifying pediatric lung disease: A comparison of forced oscillation technique outcomes

“…However, ROC analysis of impedance values obtained using impulse oscillometry demonstrated that no outcomes were capable of detecting which CF children displayed abnormal spirometry results . In addition, it has been shown that FOT outcomes do not reflect the progression of the underlying structural lung disease in cystic fibrosis . Our study does not have the ability to directly comment on the relationship between FOT data and physiological findings.…”

“…A diagnosis of cystic fibrosis was made following newborn screening and children recruited through CF clinics at Princess Margaret Hospital (Perth, Australia). FOT was performed during annual surveillance visits as detailed by Ramsey et al…”

Within‐breath changes in respiratory system impedance in children with cystic fibrosis

“…Gangell et al found that on average CF children have higher Rrs and lower Xrs compared with reference values, and that CF children with current respiratory symptoms have higher Rrs and lower Xrs compared with asymptomatic children . Ramsey et al found that FOT outcomes were not sensitive to lung inflammation, pro‐inflammatory pathogens, structural lung abnormalities, or longitudinal progression of disease in a large cohort of pre‐school children with CF . Sakarya et al found that oscillatory mechanics differed between children with CF and healthy controls, that they got worse during exacerbation and improved after recovery …”

“…25 Ramsey et al found that FOT outcomes were not sensitive to lung inflammation, pro-inflammatory pathogens, structural lung abnormalities, or longitudinal progression of disease in a large cohort of pre-school children with CF. 26 Sakarya et al found that oscillatory mechanics differed between children with CF and healthy controls, that they got worse during exacerbation and improved after recovery. 27 We analyzed the association of within-breath changes in respiratory system impedance with other lung function parameters and lung morphology.…”

Pediatric Pulmonologyyear in review 2015: Part 4

“…In a similar vein, the forced oscillation technique was found to be relatively insensitive for detecting lung disease in preschool children with CF, with similar results seen in 184 children 3–6 years of age who had pronounced respiratory disease measured by CT scan abnormalities and inflammatory mediators and in those without detectable lung disease. In addition, the progression of lung disease over 1 year was not associated with worsening forced oscillation technique outcomes …”