Signal-correction errors in the EasyOne Pro LAB multiple-breath washout device significantly impact outcomes in children and adults.

Oestreich, Marc-Alexander; Wyler, Florian; Buess, Christian; Etter, Blaise; Ramsey, Kathryn A; Latzin, Philipp (2024). Signal-correction errors in the EasyOne Pro LAB multiple-breath washout device significantly impact outcomes in children and adults. Journal of applied physiology, 136(3), pp. 460-471. American Physiological Society 10.1152/japplphysiol.00096.2022

[img] Text
oestreich-et-al-2024-signal-correction-errors-in-the-easyone-pro-lab-multiple-breath-washout-device-significantly.pdf - Accepted Version
Restricted to registered users only until 26 January 2025.
Available under License Publisher holds Copyright.

Download (2MB)

BACKGROUND

Multiple-breath washout (MBW) is an established technique to assess functional residual capacity (FRC) and ventilation inhomogeneity in the lung. Indirect calculation of nitrogen concentration requires accurate measurement of gas concentrations.

AIM

To investigate the accuracy of the CO2 concentration and molar mass (MM) values used for the indirect calculation of nitrogen concentration in a commercial MBW device (EasyOne Pro LAB (EOPL), ndd Medizintechnik AG, Switzerland) and its impact on outcomes.

METHODS

We used high-precision gas mixtures to evaluate CO2 and MM sensor output in-vivo and in-vitro. We developed updated algorithms to correct for observed errors and assessed the impact on MBW outcomes and FRC measurement accuracy compared to body plethysmography.

RESULTS

The respiratory exchange ratio (RER)-based adjustment of the measured CO2 signal used in the EOPL led to an overestimated CO2 signal (range -0.1; 1.0%). In addition, an uncorrected dependence on humidity was identified. These combined effects resulted in an overestimation of expired nitrogen concentrations (range -0.7; 2.6%), and consequently MBW outcomes. Corrected algorithms reduced the mean (SD) cumulative expired volume by 15.8% (9.7%), FRC by 6.6% (3.0%), and lung clearance index by 9.9% (7.6%). Differences in FRC between the EOPL and body plethysmography further increased.

CONCLUSION

Inadequate signal correction causes RER- and humidity-dependent expired nitrogen concentration errors and overestimation of test outcomes. Updated algorithms reduce average signal error, however, RER values far from the population average still cause measurement errors. Despite improved signal accuracy, the updated algorithm increased the difference in FRC between the EOPL and body plethysmography.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Department of Gynaecology, Paediatrics and Endocrinology (DFKE) > Clinic of Paediatric Medicine
04 Faculty of Medicine > Department of Gynaecology, Paediatrics and Endocrinology (DFKE) > Clinic of Paediatric Medicine > Paediatric Pneumology

UniBE Contributor:

Oestreich, Marc-Alexander Heinz, Wyler, Florian, Etter, Blaise Arthur, Latzin, Philipp

Subjects:

600 Technology > 610 Medicine & health

ISSN:

1522-1601

Publisher:

American Physiological Society

Language:

English

Submitter:

Pubmed Import

Date Deposited:

25 Jan 2024 16:09

Last Modified:

02 Mar 2024 00:15

Publisher DOI:

10.1152/japplphysiol.00096.2022

PubMed ID:

38269412

Uncontrolled Keywords:

Cystic fibrosis Lung clearance index Lung disease Pulmonary function testing Ventilation inhomogeneity

BORIS DOI:

10.48350/192134

URI:

https://boris.unibe.ch/id/eprint/192134

Actions (login required)

Edit item Edit item
Provide Feedback