The level of nitric oxide (NO) in an asthmatic’s exhaled breath can portend worsening asthma symptoms, and may even signify an imminent attack linked to underlying airway inflammation.

This has made the monitoring of NO levels, particularly in children, of significant interest as a potential way to help clinicians fine-tune medications and improve treatment outcomes.

However, a recent multi-center prospective study found that calibrating medications based on daily monitoring of the fractional exhaled nitric oxide (FENO) and symptoms in asthmatic children showed no significant improvement over medicating based on daily symptom monitoring alone.

The results were reported in the second issue for January of the American Journal of Respiratory and Critical Care Medicine, a publication of the American Thoracic Society.

Johan C. de Jongste, M.D., Ph.D., at the Erasmus University Medical Center-Sophia Children’s Hospital in the Netherlands, and colleagues randomized 151 children from 15 academic centers and hospitals with mild to moderate asthma to a 30-week monitoring course. Families were called every three weeks and reported on the daily symptoms in the prior three weeks. The child’s medication was adjusted accordingly.

The researchers compared the rates of exacerbation, symptoms, use of medications and other endpoints between the last 12 weeks in the two groups. There were no significant differences whether or not FENO had been part of the daily monitoring. However, both groups enjoyed an impressive overall improvement in symptoms, despite a reduction of about 50 percent in inhaled steroid dose, suggesting considerable benefit of frequent monitoring.