A simple method for estimating respiratory solute dilution in exhaled breath condensates. Am J Respir Crit Care Med 2003 Dec 15;168(12):1500-5
Date
09/27/2003Pubmed ID
14512268DOI
10.1164/rccm.200307-920OCScopus ID
2-s2.0-0347362532 (requires institutional sign-in at Scopus site) 167 CitationsAbstract
Exhaled breath condensates have been widely used to detect inflammatory mediators in the fluid that covers airway surfaces of patients with inflammatory lung disorders. This approach is much less invasive than bronchoalveolar lavage, but respiratory droplets are markedly diluted by large and variable amounts of water vapor. We estimated the dilution of respiratory droplets by comparing concentrations of nonvolatile, reference indicators (total nonvolatile cations, urea or conductivity) in 18 normal subjects with normal plasma concentrations by assuming similar concentrations in the respiratory fluid and plasma. The volatile cation, NH4+ (most of which is delivered as NH3 gas from the mouth), represented 93 +/- 3% (SEM) of the condensate cations. More than 99% of the NH4+ was removed by lyophilization, making it possible to use conductivity to estimate total nonvolatile ionic concentrations and facilitating analysis of urea. Conductivity was significantly correlated with electrolyte and urea concentrations. Estimates of dilution based on total cations, conductivity, and urea were not significantly different (cations: 20,472 +/- 2,516; conductivity: 21,019 +/- 2,427; and urea: 18,818 +/- 2,402). These observations suggest that the conductivity of lyophilized samples can be used as an inexpensive, simple, and reliable method for estimating dilution of nonvolatile, hydrophilic mediators in condensates.
Author List
Effros RM, Biller J, Foss B, Hoagland K, Dunning MB, Castillo D, Bosbous M, Sun F, Shaker RAuthor
Reza Shaker MD Assoc Provost, Sr Assoc Dean, Ctr Dir, Chief, Prof in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdultBreath Tests
Electric Conductivity
Electrolytes
Extravascular Lung Water
Female
Humans
Male