Measurement of functional residual capacity during mechanical ventilation. Comparison of a computerized open nitrogen washout method with a closed helium dilution method

1983 ◽  
Vol 9 (2) ◽  
pp. 91-93 ◽  
Author(s):  
J. Ibañez ◽  
J. M. Raurich ◽  
S. G. Moris
Keyword(s):  
Mechanical Ventilation ◽  
Functional Residual Capacity ◽  
Dilution Method ◽  
Nitrogen Washout ◽  
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 Accurate Measurement of Functional Residual Capacity and Oxygen Consumption of Patients on Mechanical Ventilation

1983 ◽  
Vol 11 (2) ◽  
pp. 151-157 ◽  
Author(s):  
Kevin R. Cooper ◽  
Peter A. Boswell
Keyword(s):  
Intensive Care Unit ◽  
Mechanical Ventilation ◽  
Intensive Care ◽  
Oxygen Consumption ◽  
Functional Residual Capacity ◽  
Lung Model ◽  
Capacity Measurement ◽  
Icu Patients ◽  
Residual Capacity

We developed an apparatus and technique for the simultaneous measurement of functional residual capacity and oxygen uptake (V̇O2) for use in intensive care unit (ICU) patients. The accuracy of the functional residual capacity measurement was proven using an in vitro lung model and the reproducibility of this measurement was established by use in ICU patients. We tested the accuracy of the V̇O2 measurement in comparison with two other methods in common use among ICU patients and our method proved accurate. We conclude that this technique for measurement of functional residual capacity and V̇O2 is highly accurate and easily applied to patients on any mode of mechanical ventilation.

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