Lung clearance index (LCI) is the most used outcome from the multiple-breath washout test. As known for decades, the LCI is not linearly related to dead space ventilation, giving difficulties interpreting changes over time and in clinical trials. We present a new and improved outcome based on LCI, the ventilation distribution efficiency (VDE), which solves this problem by being linearly related to dead space ventilation. A pediatric age range reference equation for VDE is presented.
The efficacy of 2 years of treatment with ursodeoxycholic acid (UDCA) in cystic fibrosis (CF)-associated liver disease was evaluated by liver biopsies and liver function tests in 10 patients aged 8 to 28 years. The metabolism of UDCA was investigated by analysis of urinary bile acids with fast atom bombardment mass spectrometry (FABMS) and gas-liquid chromatography–mass spectrometry. Eight patients responded with normalization of liver function tests (LFT) and all with decreased serum levels of immunoglobulin G (IgG). Blind evaluation of liver biopsies indicated improved liver morphology with less inflammation and/or bile duct proliferation than before treatment with UDCA in 7 patients. Only 1 patient had signs of progression of clinical liver disease. The proportion of UDCA and isoUDCA in urine varied, but increased during treatment from a mean (median) of approximately 4% (3%) to 40% (40%) of total bile acids. The increase was not related to LFT. The secondary bile acids, such as lithocholic acid (LCA) and deoxycholic acid (DCA), did not increase significantly. The excretion pattern of glycosidic conjugates of UDCA and its metabolites was similar to that found in healthy individuals, UDCA and isoUDCA being mainly excreted in conjugation with N-acetylglucosamine. This study shows that UDCA modulates inflammation in CF-associated liver disease and indicates improvement of liver morphology during 2 years of treatment.
Background: LCI from SF6 multiple breath washout (MBW) is more sensitive than spirometry to detect early CF lung disease and correlates closely to CT lung changes in older CF subjects [1]. Aim: To see if increased LCI during the preschool period correlates to elevated LCI, CXR abnormalities (Northern score) and reduced FEV1.0 at age seven. Methods: All CF patients born between 1995 and 2002, attending our center, and who had done at least one MBW at an annual review between age 0.6 to 4.0 years and retested at age seven with MBW, spirometry and CXR evaluated with Northern score [2] were included. Results: Out of 24 children included (17M, median age at dx 0.4, range 0.0-2.6 yrs) four had one, six had two and 14 three MBW done, before age seven. For mean age and LCI at each age period see table 1. Median (range) FEV1 at age 7 was 94% pred, (73;116). Mean LCI at age 1-3 yrs did not correlate to LCI (rs=0.26, p=0.228) or FEV1 (rs=0.09, p=0.702) at age 7 but correlated to Northern score (rs=0.52, p=0.010). Conclusion: Increased LCI in the preschool years correlates with the degree of structural lung changes at age 7. References: 1Gustafsson et al. Thorax. 2008;63:129-34. 2Conway et al. Thorax. 1994;49:860-2
Aim: To assess the agreement of Lung Clearance Index (LCI) and functional residual capacity (FRC) results from nitrogen N2 multiple breath washout (MBW) recordings using the ExhalyzerD (Eco Medics AG, Duernten, Switzerland) obtained with the commercial software Spiroware and in-house off-line software in children with CF and different severity of airway disease. Methods: Recalculation of recordings using TestPoint by which the algorithms differ mainly with respect to synchronization of gas to flow signals and definition of end-tidal N2 concentration. Results: 36 children with CF (11 F, 19 dF/dF, median age 12.2, range 6.2-17.9 yrs) with a median FEV1 of 86% (range 60-114) performed N2 MBW with at least two acceptable tracings . LCI (mean (SD)) agreed well, Spiroware: 9.3 (3.0) vs. TestPoint 9.3 (2.75) (n.s.). FRC (Spiroware) was significantly higher than FRC(TestPoint), 2.16 (0.94)L vs. (1.93L (0.85)L (p<0.001), the difference increasing with size of FRC but not with LCI. Similarly, cumulated expiratory volume (CEV)( Spiroware) was significantly higher compared to CEV(TestPoint) being 20.8(14.1)L vs. 18.0(12.9)L (p<0.001). Conclusion: Overall the two algorithms agree well with respect to CI despite differences of calculated FRC and CEV, which are cancelled out when calculating LCI. The results are reassuring but point to the need for meticulous standardization not only of procedures but also of software algorithms.
Abstract Background Aspergillus fumigatus is the most common filamentous fungus isolated from the airways of people with cystic fibrosis (CF). The aim of this study was to investigate how chronic A. fumigatus colonization affects lung function in people with CF, to identify risk factors for colonization, and to evaluate antifungal treatment of asymptomatic Aspergillus colonization. Methods Data from 2014–2018 was collected from the Swedish CF registry and medical records. Baseline data before the start of A. fumigatus colonization was compared with the two succeeding years to evaluate how colonization and treatment affected lung function and other clinical aspects. Results A total of 437 patients were included, of which 64 (14.6%) became colonized with A. fumigatus during the study period. Inhaled antibiotics was associated with A. fumigatus colonization (adjusted OR 3.1, 95% CI 1.6–5.9, p < 0.05). Fungal colonization was not associated with a more rapid lung function decline or increased use of IV-antibiotics compared to the non-colonized group, but patients with A. fumigatus had more hospital days, a higher increase of total IgE, and higher eosinophil counts. In the Aspergillus group, 42 patients were considered to be asymptomatic. Of these, 19 patients received antifungal treatment. Over the follow up period, the treated group had a more pronounced decrease in percent predicted Forced Expiratory Volume in one second (ppFEV1) compared to untreated patients (− 8.7 vs − 1.4 percentage points, p < 0.05). Conclusion Inhaled antibiotics was associated with A. fumigatus colonization, but no association was found between persistent A. fumigatus and subsequent lung function decline. No obvious benefits of treating asymptomatic A. fumigatus colonization were demonstrated.
Aims We aimed to describe the clinical, economic, and societal burdens of cystic fibrosis (CF) and impact of CF transmembrane conductance regulator modulator (CFTRm) treatment on people with CF, caregivers, and healthcare systems.
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