pH, partial oxigen and carbon dioxide pressure determination in exhaled breath condensate of children with asthma

Abstract

The aim of the study was to determine the values of pH, partial oxigen pressure (pO2) and partial carbon dioxide pressure (pCO2) in exhaled breath condensate (EBC). EBC was collected from a total of 53 children (5 to 14 years), divided into two groups: children with moderate persistent asthma (N=34) and clinically healthy children (N=19). Two EBC samples were obtained from each child with asthma: the first one was argon overlined and the second one was argon bubbled. The pH values were statistically significantly lower in the group of asthmatic children (6.663±0.257) than in the control group (6.860±0.354). Children with asthma had stastistically significant higher values of pO2 (20.38±2.51 kPa) than children in the control group (16.96±3.38), and the values of pCO2 were not statistically significant. The values of pH and gases were significantly different depending on the sample argonization. If there is the possibility to determine pH and gases right after sampling, the EBC sample should be overlined with argon in order to prevent the influence of the ambiental air. The reproducibility and the final clinical use of this method of preparation and sample analysis is yet to be determined.