Exhaled Breath Condensate and Dyspnea in COPD.

Chronic obstructive pulmonary disease (COPD) possesses a crucial position in the field of respiratory medicine as there are still unsolved issues in its whole spectrum. One promising tool that is believed to provide answers to various problems in COPD is the exhaled breath condensate (EBC). Its wealth due to its content mirrors the ongoing actions taking place in the lungs and especially the two processes blamed for the pathophysiology of COPD, the inflammation and the oxidative stress. Attempts to connect the products of the analysis of the EBC with the clinical manifestations of COPD such as dyspnea are scarce. Up to date research has shown a positive correlation between the elevated levels of some markers of EBC such as H2O2 and 8-isoprostane and dyspnea, while others present ambiguous results. The severity of COPD also seems to be connected with their increase. The purpose of this chapter is to highlight these findings and present potential correlations. Further research in EBC and its association with the clinical phenotypes of COPD and especially dyspnea is necessary.