scholarly journals The effect of inert gas choice on multiple breath washout in healthy infants: differences in lung function outcomes and breathing pattern

2017 ◽  
Vol 123 (6) ◽  
pp. 1545-1554 ◽  
Author(s):  
Per M. Gustafsson ◽  
Lovisa Bengtsson ◽  
Anders Lindblad ◽  
Paul D. Robinson
Keyword(s):  
Functional Residual Capacity ◽  
Sulfur Hexafluoride ◽  
Breathing Pattern ◽  
Inert Gas ◽  
Respiratory Drive ◽  
Quiet Sleep ◽  
Lung Clearance ◽  
Healthy Infants ◽  
Lung Clearance Index ◽  
Residual Capacity

The detrimental effects on breathing pattern during multiple breath inert gas washout (MBW) have been described with different inhaled gases [100% oxygen (O2) and sulfur hexafluoride (SF6)] but detailed comparisons are lacking. N2- and SF6-based tests were performed during spontaneous quiet sleep in 10 healthy infants aged 0.7–1.3 yr using identical hardware. Differences in breathing pattern pre and post 100% O2 and 4% SF6 exposure were investigated, and the results obtained were compared [functional residual capacity (FRC) and lung clearance index (LCI)]. During 100% O2 exposure. mean inspiratory flow (“respiratory drive”) decreased transiently by mean (SD) 28 (9)% ( P < 0.001), and end-tidal CO2 (carbon dioxide) increased by mean (SD) 0.3 (0.4)% units ( P < 0.05) vs. air breathing prephase. During subsequent N2 washin (i.e., recovery phase), the pattern of change reversed. No significant effect on breathing pattern was observed during SF6 testing. In vitro testing confirmed that technical artifacts did not explain these changes. Mean (SD) FRC and LCI in vivo were significantly higher with N2 vs. SF6 washout: 216 (33) vs. 186 (22) ml ( P < 0.001) and 8.25 (0.85) vs. 7.55 (0.57) turnovers ( P = 0.021). Based on these results, SF6 based MBW is the preferred methodology for tests in this age range. NEW & NOTEWORTHY Inert gas choice for multiple breath inert gas washout (MBW) in infants has important consequences on both breathing pattern during test performance and the functional residual capacity and lung clearance index values obtained. Data suggest the detrimental effect of breathing pattern of 100% O2 and movement of O2 across the alveolar capillary membrane, with direct effects on MBW outcomes. SF6 MBW during infancy avoids this and can be further optimized by addressing the sources of technical artifact identified in this work.

Correction of sensor crosstalk error in Exhalyzer D multiple-breath washout device significantly impacts outcomes in children with cystic fibrosis

2021 ◽  
Author(s):  
Florian Wyler ◽  
Marc-Alexander H. Oestreich ◽  
Bettina Sarah Frauchiger ◽  
Kathryn A. Ramsey ◽  
Philipp T. Latzin
Keyword(s):  
Carbon Dioxide ◽  
Cystic Fibrosis ◽  
Functional Residual Capacity ◽  
Nitrogen Concentration ◽  
Lung Clearance ◽  
Cross Sensitivity ◽  
Carbon Dioxide Gas ◽  
Lung Clearance Index ◽  
Multiple Breath Washout ◽  
Residual Capacity

Rationale: Nitrogen multiple-breath washout is an established technique to assess functional residual capacity and ventilation inhomogeneity in the lung. Accurate measurement of gas concentrations is essential for the appropriate calculation of clinical outcomes. Objectives: We investigated the accuracy of oxygen and carbon dioxide gas sensor measurements used for the indirect calculation of nitrogen concentration in a commercial multiple-breath washout device (Exhalyzer D, Eco Medics AG, Duernten, Switzerland) and its impact on functional residual capacity and lung clearance index. Methods: High precision calibration gas mixtures and mass spectrometry were used to evaluate sensor output. We assessed the impact of corrected signal processing on multiple-breath washout outcomes in a dataset of healthy children and children with cystic fibrosis using custom analysis software. Results: We found inadequate correction for the cross sensitivity of the oxygen and carbon dioxide sensors in the Exhalyzer D device. This results in an overestimation of expired nitrogen concentration, and consequently multiple-breath washout outcomes. Breath-by-breath correction of this error reduced the mean (SD) cumulative expired volume by 19.6 (5.0)%, functional residual capacity by 8.9 (2.2)%, and lung clearance index by 11.9 (4.0)%. It also substantially reduced the level of the tissue nitrogen signal at the end of measurements. Conclusions: Inadequate correction for cross sensitivity in the oxygen and carbon dioxide gas sensors of the Exhalyzer D device leads to an overestimation of functional residual capacity and lung clearance index. Correction of this error is possible and could be applied by re-analyzing the measurements in an updated software version.

scholarly journals Age and height dependence of lung clearance index and functional residual capacity

2012 ◽  
Vol 41 (6) ◽  
pp. 1371-1377 ◽  
Author(s):  
Sooky Lum ◽  
Janet Stocks ◽  
Sanja Stanojevic ◽  
Angie Wade ◽  
Paul Robinson ◽  
...  
Keyword(s):  
Functional Residual Capacity ◽  
Lung Clearance ◽  
Lung Clearance Index ◽  
Residual Capacity ◽  
Height Dependence

Decrease of Functional Residual Capacity and Ventilation Homogeneity after Meeting Abstracts in Anesthetized Young Infants and Preschool Children

2006 ◽  
Vol 105 (4) ◽  
pp. 670-675 ◽  
Author(s):  
Britta S. von Ungern-Sternberg ◽  
Jürg Hammer ◽  
Andreas Schibler ◽  
Franz J. Frei ◽  
Thomas O. Erb
Keyword(s):  
Preschool Children ◽  
Neuromuscular Blockade ◽  
Functional Residual Capacity ◽  
Pulmonary Mechanics ◽  
Ventilation Distribution ◽  
Lung Clearance ◽  
Young Infants ◽  
Lung Clearance Index ◽  
Residual Capacity ◽  
The Impact

Background Based on age-dependent differences in pulmonary mechanics, the effect of neuromuscular blockade may differ in infants compared with older children. The aim of this study was to determine the impact of neuromuscular blockade and its reversal by positive end-expiratory pressure (PEEP) on functional residual capacity (FRC) and ventilation distribution in young infants and preschool children. Methods The authors studied 14 infants (aged 0-6 months) and 25 preschool children (aged 2-6 yr). FRC and lung clearance index were calculated. Measurements were taken (1) after intubation, (2) during neuromuscular blockade, and (3) during neuromuscular blockade plus application of PEEP (3 cm H2O). Results Functional residual capacity (mean +/- SD) decreased from 21.3 +/- 4.7 ml/kg to 12.2 +/- 4.8 ml/kg (P &lt; 0.001) during neuromuscular blockade in infants and from 25.6 +/- 5.9 ml/kg to 23.0 +/- 5.3 ml/kg (P &lt; 0.001) in preschool children. With the application of PEEP, FRC increased to 22.3 +/- 5.9 ml/kg (P = 0.4829, compared with baseline) in infants and 28.2 +/- 5.8 ml/kg (P &lt; 0.001) in children. The lung clearance index increased after neuromuscular blockade, whereas baseline values were regained after the application of PEEP. The changes induced by neuromuscular blockade were significantly greater in infants compared with preschool children (P &lt; 0.001). Conclusions Although the use of neuromuscular blockade decreased FRC and ventilation distribution substantially in both groups, the changes were more pronounced in young infants. With PEEP, FRC increased and ventilation homogeneity was restored. These results provide a rationale to use PEEP in anesthetized, paralyzed infants and children.

scholarly journals Differences in lung clearance index and functional residual capacity between two commercial multiple-breath nitrogen washout devices in healthy children and adults

2020 ◽  
Vol 6 (2) ◽  
pp. 00247-2019
Author(s):  
Annelies M. Zwitserloot ◽  
Evelyne J. van den Born ◽  
Lena H.A. Raaijmakers ◽  
Wouter E. Stalman ◽  
Marjanne van Smaalen ◽  
...  
Keyword(s):  
Functional Residual Capacity ◽  
Lung Model ◽  
Secondary Outcome ◽  
Lung Clearance ◽  
Nitrogen Washout ◽  
Lung Clearance Index ◽  
Residual Capacity ◽  
Helium Dilution

Multiple-breath nitrogen washout (MBNW) and its clinical parameter lung clearance index (LCI) are gaining increasing attention for the assessment of small airway function. Measurement of LCI relies on accurate assessment of functional residual capacity (FRC). The EasyOne Pro LAB (ndd) and Exhalyzer D (EM) are two commercially available MBNW devices. The aim of the study was to compare these two devices in vitro and in vivo in healthy subjects with regard to FRC, LCI and secondary outcome parameters and to relate FRCMBNW to FRC measured by body plethysmography (pleth) and helium dilution technique. MBNW measurements were performed using a lung model (FRC between 500 and 4000 mL) in vitro and in 38 subjects aged 6–65 years followed by helium dilution and pleth in vivo using fixed and relaxed breathing techniques. In vitro accuracy within 5% of lung model FRC was 67.3% for ndd, FRC was >5% higher for EM in all tests. In vivo, FRCpleth ranged from 1.2 to 5.6 L. Mean differences (limits of agreement) between FRCpleth and FRCMBNW were −7.0%, (−23.2 to 9.2%) and 5.7% (−11.2 to 22.6%) using ndd and EM, respectively. FRCndd was consistently lower than FRCEM (−11.8% (−25.6 to 2%)). LCI was comparable between the two devices (−1.3% (−21.9 to 19.3%)). There was a difference of >10 % in LCI in 12 of 38 subjects. Using the most recent software updates, both devices show relevant deviations in FRC measurement both in vitro and in vivo and individual differences in LCI in a significant proportion of subjects. The devices are therefore not interchangeable.

Functional residual capacity and lung clearance index in infants treated for esophageal atresia and tracheoesophageal fistula

2016 ◽  
Vol 51 (4) ◽  
pp. 559-562 ◽  
Author(s):  
Francesca Landolfo ◽  
Andrea Conforti ◽  
Claudia Columbo ◽  
Ferdinando Savignoni ◽  
Pietro Bagolan ◽  
...  
Keyword(s):  
Esophageal Atresia ◽  
Functional Residual Capacity ◽  
Tracheoesophageal Fistula ◽  
Lung Clearance ◽  
Lung Clearance Index ◽  
Residual Capacity

scholarly journals Leaks during multiple-breath washout: characterisation and influence on outcomes

2018 ◽  
Vol 4 (1) ◽  
pp. 00012-2017 ◽  
Author(s):  
Nina Lenherr ◽  
Kathryn A. Ramsey ◽  
Kerstin Jost ◽  
Linn Hornwall ◽  
Florian Singer ◽  
...  
Keyword(s):  
Functional Residual Capacity ◽  
Cycle Duration ◽  
European Respiratory Society ◽  
Physiological Noise ◽  
Lung Clearance ◽  
Air Leaks ◽  
Heterogeneous Effects ◽  
Lung Clearance Index ◽  
Multiple Breath Washout ◽  
Residual Capacity

Nitrogen multiple-breath washout (N2MBW) is increasingly used in patients with cystic fibrosis. The current European Respiratory Society/American Thoracic Society consensus statement for MBW recommends the rejection of measurements with leaks. However, it is unclear whether this is necessary for all types of leaks. Here, our aim was to 1) model and 2) apply air leaks, and 3) to assess their influence on the primary MBW outcomes of lung clearance index and functional residual capacity.We investigated the influence of air leaks at various locations (pre-, intra- and post-capillary), sizes, durations and stages of the washout. Modelled leaks were applied to existing N2MBW data from 10 children by modifying breath tables. In addition, leaks were applied to the equipment during N2MBW measurements performed by one healthy adolescent.All modelled and applied leaks resulted in statistically significant but heterogeneous effects on lung clearance index and functional residual capacity. In all types of continuous inspiratory leaks exceeding a certain size, the end of the washout was not reached. For practical application, we illustrated six different “red flags”, i.e. signs that enable easy identification of leaks during measurements.Air leaks during measurement significantly influence N2MBW outcomes. The influence of leaks on MBW outcomes is dependent on the location, relation to breath cycle, duration, stage of washout and size of the leak. We identified a range of signs to help distinguish leaks from physiological noise.

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