TY - JOUR

T1 - Contemporary N2 and SF6 multiple breath washout in infants and toddlers with cystic fibrosis

AU - Sandvik, Rikke M.

AU - Gustafsson, Per M.

AU - Lindblad, Anders

AU - Buchvald, Frederik

AU - Olesen, Hanne V.

AU - Olsen, Jørgen H.

AU - Skov, Marianne

AU - Schmidt, Marika N.

AU - Thellefsen, Mette R.

AU - Robinson, Paul D.

AU - Rubak, Sune

AU - Pressler, Tacjana

AU - Nielsen, Kim G.

N1 - Funding Information: This study was supported by the Danish "Children´s Lung Foundation" (Børnelungefonden), the Danish "CF foundation," "Sanatorielæge Ellen Pedersen's Mindelegat," "Kong Christian V og Dronning Louises jubilæumslegat," and "Rigshospitalet's research scholarship for PhD students." The authors express their gratitude to all the children with cystic fibrosis (CF) and their parents for their participation, and to the members of the staff at the Paediatric Pulmonary Service of Copenhagen University Hospital for their assistance, and the staff at the Department of Paediatrics and Adolescent Medicine, Danish Center of Pediatric Pulmonology and Allergology, Cystic Fibrosis Centre Aarhus, Aarhus University Hospital, Aarhus, Denmark, and the staff at the Gothenburg CF Center, Queen Silvia Children's Hospital, Gothenburg, Sweden. Funding Information: This study was supported by the Danish "Children's Lung Foundation" (Børnelungefonden), the Danish "CF foundation," "Sanatorielæge Ellen Pedersen's Mindelegat," "Kong Christian V og Dronning Louises jubilæumslegat," and "Rigshospitalet's research scholarship for PhD students." The authors express their gratitude to all the children with cystic fibrosis (CF) and their parents for their participation, and to the members of the staff at the Paediatric Pulmonary Service of Copenhagen University Hospital for their assistance, and the staff at the Department of Paediatrics and Adolescent Medicine, Danish Center of Pediatric Pulmonology and Allergology, Cystic Fibrosis Centre Aarhus, Aarhus University Hospital, Aarhus, Denmark, and the staff at the Gothenburg CF Center, Queen Silvia Children's Hospital, Gothenburg, Sweden. Publisher Copyright: © 2022 Wiley Periodicals LLC

PY - 2022

Y1 - 2022

N2 - Introduction: Multiple breath washout (MBW) is used for early detection of cystic fibrosis (CF) lung disease, with SF6MBW commonly viewed as the reference method. The use of N2MBW in infants and toddlers has been questioned for technical and physiological reasons, but a new correction of the N2signal has minimized the technical part. The present study aimed to assess the remaining differences and the contributing mechanisms for the differences between SF6 and N2MBW,corrected—such as tidal volume reduction during N2 washout with pure O2. Method: This was a longitudinal multicenter cohort study. SF6MBW and N2MBW were performed prospectively at three CF centers in the same visits on 154 test occasions across 62 children with CF (mean age: 22.7 months). Offline analysis using identical algorithms to the commercially available program provided outcomes of N2,original and N2,corrected for comparison with SF6MBW. Results: Mean functional residual capacity, FRCN2,corrected was 14.3% lower than FRCN2, original, and 1.0% different from FRCSF6. Lung clearance index, LCIN2,corrected was 25.2% lower than LCIN2,original, and 7.3% higher than LCISF6. Mean (SD) tidal volume decreased significantly during N2MBWcorrected, compared to SF6MBW (−13.1 ml [−30.7; 4.6], p < 0.0001, equal to −12.0% [−25.7; 1.73]), but this tidal volume reduction did not correlate to the differences between LCIN2,corrected and LCISF6. The absolute differences in LCI increased significantly with higher LCISF6 (0.63/LCISF6) and (0.23/LCISF6), respectively, for N2,original and N2,corrected, but the relative differences were stable across disease severity for N2,corrected, but not for N2,original. Conclusion: Only minor residual differences between FRCN2,corrected and FRCSF6 remained to show that the two methods measure gas volumes very similar in this age range. Small differences in LCI were found. Tidal volume reduction during N2MBW did not affect differences. The corrected N2MBW can now be used with confidence in young children with CF, although not interchangeably with SF6.

AB - Introduction: Multiple breath washout (MBW) is used for early detection of cystic fibrosis (CF) lung disease, with SF6MBW commonly viewed as the reference method. The use of N2MBW in infants and toddlers has been questioned for technical and physiological reasons, but a new correction of the N2signal has minimized the technical part. The present study aimed to assess the remaining differences and the contributing mechanisms for the differences between SF6 and N2MBW,corrected—such as tidal volume reduction during N2 washout with pure O2. Method: This was a longitudinal multicenter cohort study. SF6MBW and N2MBW were performed prospectively at three CF centers in the same visits on 154 test occasions across 62 children with CF (mean age: 22.7 months). Offline analysis using identical algorithms to the commercially available program provided outcomes of N2,original and N2,corrected for comparison with SF6MBW. Results: Mean functional residual capacity, FRCN2,corrected was 14.3% lower than FRCN2, original, and 1.0% different from FRCSF6. Lung clearance index, LCIN2,corrected was 25.2% lower than LCIN2,original, and 7.3% higher than LCISF6. Mean (SD) tidal volume decreased significantly during N2MBWcorrected, compared to SF6MBW (−13.1 ml [−30.7; 4.6], p < 0.0001, equal to −12.0% [−25.7; 1.73]), but this tidal volume reduction did not correlate to the differences between LCIN2,corrected and LCISF6. The absolute differences in LCI increased significantly with higher LCISF6 (0.63/LCISF6) and (0.23/LCISF6), respectively, for N2,original and N2,corrected, but the relative differences were stable across disease severity for N2,corrected, but not for N2,original. Conclusion: Only minor residual differences between FRCN2,corrected and FRCSF6 remained to show that the two methods measure gas volumes very similar in this age range. Small differences in LCI were found. Tidal volume reduction during N2MBW did not affect differences. The corrected N2MBW can now be used with confidence in young children with CF, although not interchangeably with SF6.

KW - children

KW - functional residual capacity

KW - lung clearance index

KW - lung function

KW - ventilation distribution

U2 - 10.1002/ppul.25830

DO - 10.1002/ppul.25830

M3 - Journal article

C2 - 35029068

AN - SCOPUS:85123584457

VL - 57

SP - 945

EP - 955

JO - Pediatric pulmonology. Supplement

JF - Pediatric pulmonology. Supplement

SN - 1054-187X

IS - 4

ER -