Exhaled nitric oxide

Nitric oxide can be detected in the exhaled air of animals and normal human subjects, is increased in patients with asthma and bronchiectasis, and may be modulated by inhaled corticosteroids. Nitric oxide may provide a noninvasive means of monitoring inflammation in the respiratory tract and the measurement of exhaled nitric oxide has attracted increasing interest. However, interpretation of exhaled nitric oxide measurements may be difficult and there is a wide variation in the reported levels of nitric oxide in exhaled air, suggesting that technical factors are important.