Abstract
Background
Multiple breath washout is a lung function test based on tidal breathing that assesses lung volume and ventilation distribution. The aim of this analysis was to use the Global Lung Function Initiative methodology to develop all-age reference equations for the multiple breath washout indices lung clearance index (LCI) and functional residual capacity (FRC).
Methods
Multiple breath washout data from healthy individuals were collated from sites. Data were re-analysed using the latest software versions. Reference equations were derived using the lambda-mu-sigma (LMS) method using the generalised additive models of location shape and scale programme in R. The impact of equipment type, inert tracer gas, and equipment dead space volume on the derived reference ranges were investigated.
Results
Data from 23 sites (n=3647 test occasions) were submitted. Reference equations were derived from 1581 unique observations from participants between the ages of 2 and 81 years. Equipment type, inert tracer gas, and equipment dead space volume did not significantly affect the prediction equations for either LCI or FRC. Reference equations for LCI include age as the only predictor, whereas sex-specific reference equations for FRC included height and age.
Conclusions
Global Lung Function Initiative reference equations for multiple breath washout variables provide a standard for reporting and interpretation of LCI and FRC.
Multiple breath washout is a lung function test based on tidal breathing that assesses lung volume and ventilation distribution. The aim of this analysis was to use the Global Lung Function Initiative methodology to develop all-age reference equations for the multiple breath washout indices lung clearance index (LCI) and functional residual capacity (FRC).
Methods
Multiple breath washout data from healthy individuals were collated from sites. Data were re-analysed using the latest software versions. Reference equations were derived using the lambda-mu-sigma (LMS) method using the generalised additive models of location shape and scale programme in R. The impact of equipment type, inert tracer gas, and equipment dead space volume on the derived reference ranges were investigated.
Results
Data from 23 sites (n=3647 test occasions) were submitted. Reference equations were derived from 1581 unique observations from participants between the ages of 2 and 81 years. Equipment type, inert tracer gas, and equipment dead space volume did not significantly affect the prediction equations for either LCI or FRC. Reference equations for LCI include age as the only predictor, whereas sex-specific reference equations for FRC included height and age.
Conclusions
Global Lung Function Initiative reference equations for multiple breath washout variables provide a standard for reporting and interpretation of LCI and FRC.
| Original language | English |
|---|---|
| Journal | European Respiratory Journal |
| Early online date | 26 Sept 2024 |
| DOIs | |
| Publication status | Early online date - 26 Sept 2024 |
Publications and Copyright Policy
This work is licensed under Queen’s Research Publications and Copyright Policy.Keywords
- ERS technical standard:
- Lung cancer
- Global Lung Function Initiative
- breath washout indices
Access to Document
- ERS technical standard: Global Lung Function Initiative reference values for multiple breath washout indices
Copyright 2024 the authors. This is an accepted manuscript distributed under a Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.