Exhaled nitric oxide as an indicator of severity of asthmatic inflammation

Traditional assessment of severity of asthma relies on an evaluation of signs and symptoms and pulmonary function tests. These pulmonary function tests, such as peak expiratory how rates, forced vital capacity, and forced expiratory dow rates, are indirect measures of airway caliber only, and not inflammation, Since asthma is an inflammatory disease, a measure of the degree of inflammation would be helpful in quantitating severity and titrating of anti-inflammatory therapy. A noninvasive method for measuring pulmonary inflammation would therefore be helpful to assist the emergency physician in initial treatment and assist in titration of anti-inflammatory therapy during repeat visits. Exhaled nitric oxide (NO) assays are convenient and practical and may fulfill this cole. In this review we discuss the role of NO in asthmatic inflammation and the role that exhaled NO values may play in the emergency management of asthma.