A noninvasive method to collect nasally exhaled air condensate in humans of all ages

Background The analysis of exhaled breath condensate may provide valuable i nsights into inflammatory and other metabolic processes of the lungs. Howev er, its collection by active exhalation with conventional methods is cumber some, demands a substantial level of co-operation with high motivation and is very difficult or impossible in children younger than about 4-6 years or in the elderly. A comfortable, noninvasive and efficient method is desirab le. Design and patients For collection a high-performance pump connected to a c old trap and nasal prongs were used. The volume of the condensate collected was assessed in 141 children of all ages and five adults. As an example fo r a low molecular component, H2O2 a marker of oxidative stress, was determi ned fluorometrically. Results On average, in healthy children from 4 weeks to 18 years of age, 84 .0 (79.4, 87.3) muL min(-1) of nasally exhaled air condensate were collecte d. The volume obtained was about 45% less in 1-6-year-old children, increas ed linearly with collection time, and averaged about 20-30% of the exhaled water vapour. The concentration of H2O2 in the healthy children was 0.49 (0 .48, 0.61) muM and did not depend on age, the time of the day, family, or p ersonal history of atopy and sex. Conclusions The method described is generally applicable, comfortable, noni nvasive, safe and efficient and allows the collection of nasally exhaled ai r condensate for the evaluation of metabolic processes of the lungs.