Open AccessThe concentration of hydrogen peroxide in exhaled air
depends on expiratory flow rate
Author(s) -
Schleiss M.B.,
Holz O.,
Behnke M.,
Richter K.,
Magnussen H,
Jörres R.a
Publication year - 2000
Publication title -
european respiratory journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.021
H-Index - 241
eISSN - 1399-3003
pISSN - 0903-1936
DOI - 10.1034/j.1399-3003.2000.16f16.x
Subject(s) - hydrogen peroxide , exhaled air , chemistry , exhaled breath condensate , volumetric flow rate , airway , medicine , anesthesia , asthma , biochemistry , toxicology , thermodynamics , biology , physics
Hydrogen peroxide (H 2 O 2 ) is known to be detectable in exhaled air. The present study aimed to determine whether the concentration of exhaled H 2 O 2 depends on expiratory flow rate in order to make inferences on the site of its production within the lung. Breath condensate was collected in cooled Teflon tubes, at three different expiratory flow rates, in 15 healthy or mild asthmatic subjects. Tests were repeated 2–5 times to assess reproducibility. Mean± sem concentrations of H 2 O 2 at flow rates of 140, 69 and 48 mL·s ‐1 were 0.12± 0.02, 0.19±0.02 and 0.32±0.03 μM, respectively. These values differed significantly from each other (p<0.001). For comparison, average coefficients of variability within repeated measurements at each of the three flow rates were 68, 62 and 82%, respectively. These data demonstrate that the concentration of exhaled hydrogen peroxide depends on expiratory flow rate. Since flow dependence is an indicator of production within the airways, this result suggests that, to a large extent, the exhaled hydrogen peroxide originates within the airways. However, even under strictly controlled con‐ditions, a high degree of variability persists, which may limit the usefulness of exhaled hydrogen peroxide as a marker of airway inflammation.