Background: Lung clearance index (LCI), a measure of ventilation inhomogeneity derived from the multiplebreath inert gas washout (MBW) technique, has been shown to detect abnormal lung function more readily than spirometry in preschool children with cystic fibrosis, but whether this holds true during infancy is unknown. Objectives: To compare the extent to which parameters derived from the MBW and the raised lung volume rapid thoraco-abdominal compression (RVRTC) techniques identify diminished airway function in infants with cystic fibrosis when compared with healthy controls. Methods: Measurements were performed during quiet sleep, with the tidal breathing MBW technique being performed before the forced expiratory manoeuvres. Results: Measurements were obtained in 39 infants with cystic fibrosis (mean (SD) age 41.4 (22.0) weeks) and 21 controls (37.0 (15.1) weeks). Infants with cystic fibrosis had a significantly higher respiratory rate (38 (10) vs 32 (5) bpm) and LCI (8.4 (1.5) vs 7.2 (0.3)), and significantly lower values for all forced expiratory flow-volume parameters compared with controls. Girls with cystic fibrosis had significantly lower forced expiratory volume ) than boys (mean (95% CI girls-boys): -1.2 (-2.1 to 20.3) for FEV 0.5 Z score; FEF 25-75 : -1.2 (-2.2 to 20.15)). When using both the MBW and RVRTC techniques, abnormalities were detected in 72% of the infants with cystic fibrosis, with abnormalities detected in 41% using both techniques and a further 15% by each of the two tests performed. Conclusions: These findings support the view that inflammatory and/or structural changes in the airways of children with cystic fibrosis start early in life, and have important implications regarding early detection and interventions. Monitoring of early lung disease and functional status in infants and young children with cystic fibrosis may be enhanced by using both MBW and the RVRTC.

Background Long-term benefits of newborn screening (NBS) for cystic fibrosis (CF) have been established with respect to nutritional status, but effects on pulmonary health remain unclear. Hypothesis With early diagnosis and commencement of standardised treatment, lung function at w3 months of age is normal in NBS infants with CF. Methods Lung clearance index (LCI) and functional residual capacity (FRC) using multiple breath washout (MBW), plethysmographic (pleth) FRC and forced expirations from raised lung volumes were measured in 71 infants with CF (participants in the London CF Collaboration) and 54 contemporaneous healthy controls age w3 months. Results Compared with controls, and after adjustment for body size and age, LCI, FRC MBW and FRC pleth were significantly higher in infants with CF (mean difference (95% CI): 0.5 (0.1 to 0.9), p¼0.02; 0.4 (0.1 to 0.7), p¼0.02 and 0.9 (0.4 to 1.3), p<0.001, z-scores, respectively), while forced expiratory volume (FEV 0.5 ) and flows (FEF 25e75 ) were significantly lower (À0.9 (À1.3 to À0.6), p<0.001 and À0.7 (À1.1 to À0.2), p¼0.004, z-scores, respectively). 21% (15/70) of infants with CF had an elevated LCI (>1.96 z-scores) and 25% (17/68) an abnormally low FEV 0.5 (below À1.96 z-scores). While only eight infants with CF had abnormalities of LCI and FEV 0.5 , using both techniques identified abnormalities in 35% (24/68). Hyperinflation (FRC pleth >1.96 z-scores) was identified in 18% (10/56) of infants with CF and was significantly correlated with diminished FEF 25e75 (r¼À0.43, p<0.001) but not with LCI or FEV 0.5 . Conclusion Despite early diagnosis of CF by NBS and protocol-driven treatment in specialist centres, abnormal lung function, with increased ventilation inhomogeneity and hyperinflation and diminished airway function, is evident in many infants with CF diagnosed through NBS by 3 months of age.

The clinical advantages of the newborn screening programme (NBS) in the UK are well described in the literature. However, there has been little exploration of the psychosocial impact on the family. This study followed the principles of grounded theory to explore parents’ experiences of receiving the initial positive NBS result for their child with cystic fibrosis (CF) or sickle cell disease (SCD). Semi-structured, qualitative interviews were conducted with 22 parents (12 mothers and 10 fathers) whose children had been diagnosed with CF or SCD via NBS and were under the age of 1 year at the time of interview. The main themes that arose from the data were; parents previous knowledge of the condition and the NBS programme, the method of delivery and parental reactions to the result, sharing the results with others, the impact on parental relationships and support strategies. Study conclusions indicate that most parents thought initial positive NBS results should be delivered by a health professional with condition specific knowledge, preferably with both parents present. Genetic counselling needs to include a focus on the impact of NBS results on parental relationships. Careful consideration needs to be given to strategies to support parents of babies who have positive NBS results both in terms of the psychological health and to assist them in sharing the diagnosis.

The aim of this study was to determine whether a relationship exists between the circulating concentration of antioxidants, or markers of oxidative stress, and pulmonary function in cystic fibrosis patients. Plasma was obtained from 34 patients attending a cystic fibrosis clinic. Oxidative stress was investigated by measuring the concentrations of circulating lipid hydroperoxides and malondialdehyde (lipid peroxidation) and protein carbonyls (protein oxidation). Antioxidant status was determined from the plasma concentrations of α-tocopherol, ascorbic acid, uric acid and total sulphydryls. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and forced mid-expiratory flow (FEF25-75) were measured in 25 of the subjects by spirometry, and expressed as percentage predicted for normal height, weight and age.Lung function decreased significantly with age and was associated with decreased plasma α-tocopherol, ascorbic acid and sulphydryl concentrations. The reduction in pulmonary function correlated with elevated plasma malondialdehyde, but not with lipid hydroperoxide or protein carbonyl concentrations. Patients with severe lung dysfunction (FEV1 <50% predicted) had higher plasma concentrations of lipid hydroperoxides than those with mild-to-moderate lung dysfunction (FEV1 >50% pred).This study provides evidence that cystic fibrosis patients have inadequate antioxidant defences to cope with the elevated oxidative stress that they regularly experience. We believe that recurring oxidative lung injury contributes to the decline in pulmonary function in these patients.

The tidal and raised volume rapid thoracoabdominal compression techniques are increasingly used to detect diminished airway function in infancy. The aim of this study was to assess the relative ability of parameters measured by these techniques to identify diminished airway function in infants newly diagnosed with cystic fibrosis (CF) with and without clinical evidence of prior lower respiratory illness. A cross-sectional, prospective study design was used in which maximal flow at functional residual capacity (VmaxFRC) from the tidal technique and FVC, FEV0.5, FEF75, and FEF25-75 from the raised volume technique were measured in 47 infants with CF and 187 healthy infants of similar body size, sex distribution, ethnic group, and exposure to maternal smoking. Multiple linear regression was used to assess group differences and to calculate SD scores for each parameter for the infants with CF. Airway function was also compared with clinical assessments of respiratory status made by pediatric pulmonologists. FEV0.5 was significantly diminished in 13 infants with CF, of whom 4 had been identified by clinicians as having normal respiratory status. Only one infant with CF had a VmaxFRC below the estimated normal range. Airway function is diminished in infants with CF irrespective of prior lower respiratory illness and in those whose respiratory status is considered normal by pediatric pulmonologists. In infants with CF, the raised volume technique identified diminished airway function more frequently than the tidal technique.