Selections from Journal Watch Pediatrics and Adolescent Medicine Copyright © 2005 Massachusetts Medical Society. All rights reserved.

Measuring exhaled nitric oxide can guide the treatment of asthma ▸

The decision to titrate the dose of inhaled corticosteroids (ICS) in patients with asthma is usually based on asthma symptoms and pulmonary function tests (PFTs), but these tests are difficult to do and of uncertain accuracy. Investigators in New Zealand randomly assigned 97 patients (age range, 12 to 73 years) with persistent asthma to dose adjustment of fluticasone based on either conventional guidelines (disease symptoms and PFTs) or measurement of exhaled nitric oxide. Exhaled nitric oxide reflects bronchial-wall inflammation, airway hyper-responsiveness, and induced-sputum eosinophilia.

After a 3- to 12-month run-in phase to establish optimal ICS dose, patients were followed for 12 months, with visits every 2 months for adjustment of the fluticasone dose. Compared with controls, those in the nitric oxide group were receiving a significantly lower dose of ICS at the end of the study (370 μg/day vs. 641 μg/day) without compromising asthma control. There were no significant differences between the groups in nighttime waking, pulmonary function, levels of airway inflammation, or use of bronchodilators or prednisone. Although there was a 46% difference in asthma exacerbations favoring the nitric oxide group, this difference did not reach statistical significance (0.49 vs. 0.90 episodes per patient per year).