Comparison of lung clearance index determined by washout of N2 and SF6 in infants and preschool children with cystic fibrosis

Abstract

Background: Multiple-breath washout (MBW) has been shown to detect early impairment of lung function in children with cystic fibrosis (CF). Nitrogen (N 2 ) or sulfur hexafluoride (SF 6 ) can be used as tracer gas for MBW. Recent data indicated higher lung clearance index (LCI) values measured with N 2 -MBW than concurrent SF 6 -MBW in older children and adults, however, a comparison in infants and younger children, as well as to other outcome measures of CF lung disease is pending. Methods: N 2 -and SF 6 -MBW were performed consecutively in 31 sedated infants and preschool children with CF (mean age, 2.3 ± 0.8 years) and 20 controls (mean age, 2.3 ± 1.1 years) using the Exhalyzer D system. Children with CF also underwent chest magnetic resonance imaging (MRI). Results: Mean difference (95% CI) in LCI between N 2 -and SF 6 -MBW was 1.1 ± 0.4 (0.9 to 1.3) in controls and 2.1 ± 1.9 (1.4 to 2.8) in CF. Agreement between N 2 -and SF 6 -LCI was poor in children with CF. N 2 -LCI and SF 6 -LCI correlated with MRI, however N 2 -LCI showed a higher concordance with MRI than SF 6 -LCI. The absolute difference between N 2 -and SF 6 -LCI values increased with the severity of CF lung disease as determined by MRI scores. Conclusion: N 2 -LCI values were higher than SF 6 -LCI values in infants and preschool children with CF and controls. Better concordance of N 2 -LCI than SF 6 -LCI with chest MRI scores point towards of a higher sensitivity of N 2 -LCI to detect early lung disease in children with CF.

Multicentre feasibility of multiple-breath washout in preschool children with cystic fibrosis and other lung diseases

“…Multiple-breath washout test N 2 -MBW investigations in preschool children were established at the Airway Research Center North (ARCN), the Biomedical Research in Endstage and Obstructive Lung Disease (BREATH) centre and the TLRC before the start of this study ("experienced centres"), and were established at the Universities of Giessen and Marburg Lung Center (UGMLC) and the CF Center at Charité -Universitätsmedizin Berlin as part of this study ("unexperienced centres") [10,24]. Technical MBW procedures were compliant with the American Thoracic Society Technical Statement and were performed in awake, upright sitting children with the commercially available mainstream ultrasonic flowmeter Exhalyzer D and spiroware 3.2.1 as acquisition software (Eco Medics, Duernten, Switzerland) with N 2 as tracer gas [10,11,22,25].…”

Limitations of regional ventilation inhomogeneity indices in children with cystic fibrosis

“…Comparison of MBW results in our CF cohort with those of previous studies 1,2,13,16‐23 (E‐table 1) is complicated by differences in tracer gas, devices and settings used as well as in the age range and inclusion criteria of the study populations. For instance, the impact of using a different tracer gas (N 2 vs SF 6 ) is well documented for LCI 24‐27 . SnIII results are likely to be affected in a similar way.…”

Is FEV1 associated with quality of life in children with cystic fibrosis? An original article

“…In countries with higher prevalence of CF, early detection of the disease and screening of newborns is of particular importance (2). In these patients, lung disease starts in first months of life and remains the predominant cause of morbidity and mortality (17).…”