What it takes to implement regular longitudinal multiple breath washout tests in infants with cystic fibrosis

2020 ◽  
Vol 19 (6) ◽  
pp. 1027-1028 ◽  
Author(s):  
Marika N. Schmidt ◽  
Rikke M. Sandvik ◽  
Christian Voldby ◽  
Frederik F. Buchvald ◽  
Maria N. Jørgensen ◽  
...  
2018 ◽  
Vol 52 (5) ◽  
pp. 1800821 ◽  
Author(s):  
Laurie J. Smith ◽  
Guilhem J. Collier ◽  
Helen Marshall ◽  
Paul J.C. Hughes ◽  
Alberto M. Biancardi ◽  
...  

Hyperpolarised helium-3 (3He) ventilation magnetic resonance imaging (MRI) and multiple-breath washout (MBW) are sensitive methods for detecting lung disease in cystic fibrosis (CF). We aimed to explore their relationship across a broad range of CF disease severity and patient age, as well as assess the effect of inhaled lung volume on ventilation distribution.32 children and adults with CF underwent MBW and 3He-MRI at a lung volume of end-inspiratory tidal volume (EIVT). In addition, 28 patients performed 3He-MRI at total lung capacity. 3He-MRI scans were quantitatively analysed for ventilation defect percentage (VDP), ventilation heterogeneity index (VHI) and the number and size of individual contiguous ventilation defects. From MBW, the lung clearance index, convection-dependent ventilation heterogeneity (Scond) and convection–diffusion-dependent ventilation heterogeneity (Sacin) were calculated.VDP and VHI at EIVT strongly correlated with lung clearance index (r=0.89 and r=0.88, respectively), Sacin (r=0.84 and r=0.82, respectively) and forced expiratory volume in 1 s (FEV1) (r=−0.79 and r=−0.78, respectively). Two distinct 3He-MRI patterns were highlighted: patients with abnormal FEV1 had significantly (p<0.001) larger, but fewer, contiguous defects than those with normal FEV1, who tended to have numerous small volume defects. These two MRI patterns were delineated by a VDP of ∼10%. At total lung capacity, when compared to EIVT, VDP and VHI reduced in all subjects (p<0.001), demonstrating improved ventilation distribution and regions of volume-reversible and nonreversible ventilation abnormalities.


2020 ◽  
Vol 6 (4) ◽  
pp. 00408-2020
Author(s):  
Mirjam Stahl ◽  
Cornelia Joachim ◽  
Ines Kirsch ◽  
Tatjana Uselmann ◽  
Yin Yu ◽  
...  

BackgroundMultiple-breath washout (MBW)-derived lung clearance index (LCI) detects early cystic fibrosis (CF) lung disease. LCI was used as an end-point in single- and multicentre settings at highly experienced MBW centres in preschool children. However, multicentre feasibility of MBW in children aged 2–6 years, including centres naïve to this technique, has not been determined systematically.MethodsFollowing central training, 91 standardised nitrogen MBW investigations were performed in 74 awake preschool children (15 controls, 46 with CF, and 13 with other lung diseases), mean age 4.6±0.9 years at investigation, using a commercially available device across five centres in Germany (three experienced, two naïve to the performance in awake preschool children) with central data analysis. Each MBW investigation consisted of several measurements.ResultsOverall success rate of MBW investigations was 82.4% ranging from 70.6% to 94.1% across study sites. The number of measurements per investigation was significantly different between sites ranging from 3.7 to 6.2 (p<0.01), while the mean number of successful measurements per investigation was comparable with 2.1 (range, 1.9 to 2.5; p=0.46). In children with CF, the LCI was increased (median 8.2, range, 6.7–15.5) compared to controls (median 7.3, range 6.5–8.3; p<0.01), and comparable to children with other lung diseases (median 7.9, range, 6.6–13.9; p=0.95).ConclusionThis study demonstrates that multicentre MBW in awake preschool children is feasible, even in centres previously naïve, with central coordination to assure standardised training, quality control and supervision. Our results support the use of LCI as multicentre end-point in clinical trials in awake preschoolers with CF.


2018 ◽  
Vol 125 (4) ◽  
pp. 1257-1265 ◽  
Author(s):  
Lokesh Guglani ◽  
Ajay Kasi ◽  
Miah Starks ◽  
Knud E. Pedersen ◽  
Jørgen G. Nielsen ◽  
...  

Measurement of lung clearance index (LCI) by multiple breath washout (MBW) is a sensitive method for monitoring lung disease in patients with cystic fibrosis (CF). To compare nitrogen MBW (N2-MBW) and sulfur hexafluoride MBW (SF6-MBW), we connected these two gas analysis systems in series to obtain truly simultaneous measurements, with no differences other than the gas used. Nonsmoking healthy controls (HC) and subjects with CF were recruited at two institutions. The Exhalyzer-D (for N2-MBW measurement) was connected in series with the Innocor (for SF6-MBW measurement). Subjects washed in SF6 from a Douglas bag with tidal breathing and washed out SF6 and nitrogen with 100% oxygen provided as bias flow. Washout of both gases was continued past the LCI point (1/40th of equilibration concentration) in triplicate. N2-MBW resulted in higher cumulative exhaled volume, functional residual capacity (FRC), and LCI when compared with SF6-derived parameters in HC subjects ( P < 0.0001 for all comparisons). All N2-MBW parameters were also significantly higher than SF6-MBW parameters in subjects with CF ( P < 0.01 for all comparisons). After recalculation with a common FRC, N2-MBW LCI was higher than SF6-MBW LCI in subjects with CF (19.73 vs. 11.39; P < 0.0001) and in HC (8.12 vs. 6.78; P < 0.0001). Adjusting for N2 back diffusion and an offset error in the nitrogen measurement resulted in near complete agreement between the two methodologies. We found significant differences in LCI and FRC measurements using two different gases for MBW. This may have significant implications for the future use and interpretation of LCI data in clinical trials and routine clinical care. NEW & NOTEWORTHY This study provides important insights into the differences between the two techniques used for measuring lung clearance index (LCI): N2 and SF6 multiple breath washout. Differences between measurements made by these two methods in subjects with cystic fibrosis and healthy controls could be explained by nitrogen back diffusion and N2 offset error. This is important for use and interpretation of LCI data as an outcome measure for clinical trials and in routine clinical care.


2015 ◽  
Vol 12 (6) ◽  
pp. 932-939 ◽  
Author(s):  
Padmaja Subbarao ◽  
Carlos Milla ◽  
Paul Aurora ◽  
Jane C. Davies ◽  
Stephanie D. Davis ◽  
...  

2021 ◽  
Vol 20 ◽  
pp. S253
Author(s):  
M. Dumas ◽  
R. Jensen ◽  
J. Au ◽  
S. Munidasa ◽  
J. Woods ◽  
...  

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