Open AccessThe Single-Breath Diffusing Capacity of CO and NO in Healthy Children of European Descent
Author(s) -
Astrid Thomas,
Birgitte Hanel,
Jacob Louis Marott,
Frederik Buchvald,
Jann Mortensen,
Kim G. Nielsen
Publication year - 2014
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0113177
Subject(s) - diffusing capacity , inhalation , carbon monoxide , pulmonary diffusing capacity , medicine , chemistry , lung , anesthesia , lung function , biochemistry , catalysis
Rationale The diffusing capacity (D L ) of the lung can be divided into two components: the diffusing capacity of the alveolar membrane (Dm) and the pulmonary capillary volume (Vc). D L is traditionally measured using a single-breath method, involving inhalation of carbon monoxide, and a breath hold of 8–10 seconds (D L,CO ). This method does not easily allow calculation of Dm and Vc. An alternative single-breath method (D L,CO,NO ), involving simultaneous inhalation of carbon monoxide and nitric oxide, and traditionally a shorter breath hold, allows calculation of Dm and Vc and the D L,NO /D L,CO ratio in a single respiratory maneuver. The clinical utility of Dm, Vc, and D L,NO /D L,CO in the pediatric age range is currently unknown but also restricted by lack of reference values. Objectives The aim of this study was to establish reference ranges for the outcomes of D L,CO,NO with a 5 second breath hold, including the calculated outcomes Dm, Vc, and the D L,NO /D L,CO ratio, as well as to establish reference values for the outcomes of the traditional D L,CO method, with a 10 second breath hold in children. Methods D L,CO,NO and D L,CO were measured in healthy children, of European descent, aged 5–17 years using a Jaeger Masterscreen PFT. The data were analyzed using the Generalized Additive Models for Location Scale and Shape (GAMLSS) statistical method. Measurements and Main Results A total of 326 children were eligible for diffusing capacity measurements, resulting in 312 measurements of D L,CO,NO and 297 of D L,CO , respectively. Reference equations were established for the outcomes of D L,CO,NO and D L,CO , including the calculated values: Vc, Dm, and the D L,NO /D L,CO ratio. Conclusion These reference values are based on the largest sample of children to date and may provide a basis for future studies of their clinical utility in differentiating between alterations in the pulmonary circulation and changes in the alveolar membrane in pediatric patients.