Exhaled nitric oxide in asthma

Abstract

Although asthma is a well recognized inflammatory disease and the most effective treatment for asthma are inhaled corticosteroids, physicians caring for asthmatic patients were not supported, till recently, by an easy-to-obtain laboratory marker of airway inflammation. In the last years many studies have established a significant relationship between changes in nitric oxide concentration (FENO) in exhaled breath and other markers of airway inflammation. The technique used to measure FENO is non-invasive, reproducible, sensitive, and easy to perform. Consequently, there is growing interest in the use of FENO in the management of asthma. The purpose of this review is to promote a basic understanding of the physiologic action of NO in the respiratory system, measurement technique, and the application of FENO measurement in clinical practice for diagnosing and treating asthma.