Comparison of helium dilution and nitrogen washout measurements of functional residual capacity in infants and very young children

1992 ◽  
Vol 13 (4) ◽  
pp. 250-254 ◽  
Author(s):  
Robert S. Tepper ◽  
Steve Asdell
Keyword(s):  
Young Children ◽  
Functional Residual Capacity ◽  
Nitrogen Washout ◽  
Very Young Children ◽  
Residual Capacity ◽  
Helium Dilution

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.

scholarly journals In vitro and in vivo functional residual capacity comparisons between multiple-breath nitrogen washout devices

2017 ◽  
Vol 3 (4) ◽  
pp. 00011-2017 ◽  
Author(s):  
Katrina O. Tonga ◽  
Paul D. Robinson ◽  
Claude S. Farah ◽  
Greg G. King ◽  
Cindy Thamrin
Keyword(s):  
Functional Residual Capacity ◽  
Measurement Accuracy ◽  
Lung Model ◽  
Nitrogen Washout ◽  
Device Validation ◽  
Residual Capacity

Functional residual capacity (FRC) accuracy is essential for deriving multiple-breath nitrogen washout (MBNW) indices, and is the basis for device validation. Few studies have compared existing MBNW devices. We evaluated in vitro and in vivo FRC using two commercial MBNW devices, the Exhalyzer D (EM) and the EasyOne Pro LAB (ndd), and an in-house device (Woolcock in-house device, WIMR).FRC measurements were performed using a novel syringe-based lung model and in adults (20 healthy and nine with asthma), followed by plethysmography (FRCpleth). The data were analysed using device-specific software. Following the results seen with ndd, we also compared its standard clinical software (ndd v.2.00) with a recent upgrade (ndd v.2.01).WIMR and EM fulfilled formal in vitro FRC validation recommendations (>95% of FRC within 5% of known volume). Ndd v.2.00 underestimated in vitro FRC by >20%. Reanalysis using ndd v.2.01 reduced this to 11%, with 36% of measurements ≤5%. In vivo differences from FRCpleth (mean±sd) were 4.4±13.1%, 3.3±11.8%, −20.6±11% (p<0.0001) and −10.5±10.9% (p=0.005) using WIMR, EM, ndd v.2.00 and ndd v.2.01, respectively.Direct device comparison highlighted important differences in measurement accuracy. FRC discrepancies between devices were larger in vivo, compared to in vitro results; however, the pattern of difference was similar. These results represent progress in ongoing standardisation efforts.

Total respiratory compliance and functional residual capacity in young children

1986 ◽  
Vol 2 (6) ◽  
pp. 321-326 ◽  
Author(s):  
A. Greenough ◽  
J. Stocks ◽  
U. Nothen ◽  
R Helms
Keyword(s):  
Young Children ◽  
Functional Residual Capacity ◽  
Respiratory Compliance ◽  
Residual Capacity
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