Airway nitrogen oxide measurements in asthma and other pediatric respiratory diseases

Markers for airway inflammation that can be measured noninvasively in expir ed air may be helpful in treating patients with asthma. For example, levels of nitric oxide are high in the breath of children with asthma exacerbatio ns and decrease with anti-inflammatory therapy. Expired nitric oxide testin g has now been standardized and may be useful for ch;ldr en with recurring wheezing that is diagnostically or therapeutically challenging. However, th e results may be influenced by several biochemical and anatomic variables a nd must therefore be interpreted with caution.