Abstract

Inflammation has been implicated in the pathogenesis of many respiratory diseases including asthma. Determining the severity of disease and the necessity for antiinflammatory therapy are important aspects of asthma management. Recently, there has been interest in methods of measuring inflammation. Because of the difficulties associated with invasive methods of monitoring airway inflammation, interest has focused on developing non-invasive monitoring methods such as measurement of nitric oxide (NO) in exhaled breath. NO is not the only marker that can be measured in exhaled air. There is now increasing evidence that other volatile gases (carbon monoxide, ethane, pentane) and mediators (hydrogen peroxide, nitrites, isoprostanes) in expired condansates may be useful and complementary to the information provided by NO. Although most studies have been conducted in asthmatic patients, abnormalities in exhaled markers have been found in several other lung diseases.