Partial oxygen and carbon dioxide pressure of exhaled breath condensate

Abstract

Objective: To assess (a) the effect of ambient and exhaled gases on water gas analysis and (b) the impact of argonization on the results of oxygen (Po2) and carbon dioxide (Pco2) determination in exhaled breath condensate. Methods: Samples of deionized water exposed to atmosphere and exhaled air were analyzed to assess the effect of ambient gases on the respective analyte results. Exhaled breath condensate (EBC) samples were argonized by 2 methods. Also, Po2 and Pco2 were determined in EBC obtained from healthy children. Results: Deionized water samples exposed to air showed similar Po2 and Pco2 values in ambient air. The values of Po2 were higher, and those of Pco2 lower in water after exhaled air bubbling. The values of Po2 and Pco2 were significantly higher in EBC samples protected by an argon layer. Conclusion: Ambient/exhaled gases influence gas analysis in water and EBC, respectively. Additional validation of the method is needed.