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Updated: May 27, 2026

Dual Test Gas Pulmonary Diffusing Capacity Measurement During Exercise in Humans Using the Single-Breath Method
Published on: February 2, 2024
Pulmonary diffusing capacity in healthy Caucasian children
Young-Jee Kim1, Graham L Hall, Kathy Christoph
1Department of Pediatrics, James Whitcomb Riley Hospital for Children, Indianapolis, Indiana, USA. yk3@iupui.edu
Insights
This study establishes new reference ranges for diffusing capacity to carbon monoxide (DL(CO)) and alveolar volume (V(A)) in healthy children aged 5-19, using current ATS/ERS guidelines and multi-center data.
Area of Science:
- Pediatric Pulmonology
- Respiratory Physiology
- Clinical Reference Standards
Background:
- Previous studies on pediatric pulmonary diffusing capacity used varied methodologies and predated current ATS/ERS guidelines.
- Establishing reliable reference ranges is crucial for accurate clinical assessment of lung function in children.
Purpose of the Study:
- To establish current reference ranges for diffusing capacity to carbon monoxide (DL(CO)) and alveolar volume (V(A)) in healthy Caucasian children.
- To utilize contemporary equipment and adhere to international ATS/ERS guidelines for pulmonary function testing.
Main Methods:
- Collected single-breath DL(CO) and V(A) data from healthy Caucasian children in the US (N=303) and Australia (N=176).
- Ensured all measurements met current ATS/ERS guidelines for acceptability.
- Analyzed data using regression models, considering height, age, sex, and hemoglobin levels.
Main Results:
- Derived regression equations for DL(CO) and V(A) based on height, age, and age-sex interaction.
- DL(CO)/V(A) was primarily related to height and age-sex interaction.
- Found no significant center effect for DL(CO) or DL(CO)/V(A); Australian children had smaller V(A) after adjustments.
Conclusions:
- Multi-center data can be reliably collated for deriving pediatric pulmonary function reference ranges when using standardized protocols and equipment.
- New regression equations for DL(CO) and V(A) are provided for healthy Caucasian children aged 5-19 years.
- These updated reference ranges facilitate more accurate clinical interpretation of lung function in pediatric populations.
Abstract:
Previous studies of pulmonary diffusing capacity in children differed greatly in methodologies; numbers of subjects evaluated, and were performed prior to the latest ATS/ERS guidelines. The purpose of our study was to establish reference ranges for the diffusing capacity to carbon monoxide (DL(CO) ) and alveolar volume (V(A) ) in healthy Caucasian children using current international guidelines and contemporary equipment. Healthy children from the United States (N = 303) and from Australia (N = 176) performed acceptable measurements of single breath pulmonary diffusing capacity and alveolar volume according to current ATS/ERS guidelines. The natural log of DL(CO) and V(A) were associated with height, age and an age-sex interaction term, while DL(CO) /V(A) was related to height and the age-sex interaction term only. Adjustment of DL(CO) for hemoglobin (n = 303; USA data only) resulted is a small but significant decrease in DL(CO) of ∼1% but did not significantly alter the regression equations. In this dataset there was no influence of center for DL(CO) or DL(CO) /V(A) , while Australian children had a statistically smaller V(A) (mean difference 0.14 L after accounting for height, age and age-sex; P = 0.012). We report that diffusing capacity outcomes can be collated from multiple centers using similar equipment and collection protocols. Using collated data we have derived regression equations for pulmonary diffusing capacity outcomes in healthy Caucasian children aged 5-19 years.
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