Multi-center validation study on feasibility of multiple-breath washout technique in infants and toddlers with cystic fibrosis

Background: CF lung disease starts in the first months of life often before the onset of clinical symptoms. Multiple breath washout (MBW) has been shown to detect abnormal lung function in infants and young children in single-centre trials. Objective: The aim of this study was to determine the feasibility and validity of MBW in 0-4 year old children with CF and non-CF controls in a multi-center approach within DZL centres, namely Heidelberg, Giessen and Lubeck. Methods: Training was performed for staff members of all centres at Heidelberg and at their centre. 66 SF6-MBW investigations were performed in sedated children (mean age 2.3 ± 1.2 y; 44 with CF (mean age 2.4 ± 1.2 y), 10 controls (mean age 2.4 ± 1.2 y) and 12 disease controls (mean age 1.9 ± 1.1 y)). Washout traces were analysed centrally at Heidelberg. Results: After training of the staff at the different sites, MBW measurements were successful in 89.6% of children. Children with CF showed an elevated lung clearance index (LCI) of 7.3 ±1.1 (range, 6.1 – 12.6) compared to pulmonary healthy control children (6.6 ±0.4, P =0.0017). Non-CF disease control children9s LCI was also elevated with 7.3 ±1.1 (range, 6.2 – 9.6) compared to pulmonary healthy controls ( P =0.0409), but not compared to children with CF ( P =0.9851). CV of the LCI were not significantly different between centres (CF, P >0.05; disease control, P >0.05). Conclusions: We conclude that training and supervision is necessary to achieve good results from MBW measurements. MBW is able to detect alterations of pulmonary function in small children with CF and other pulmonary diseases in the multi-centre setting.