New Test Helps Track Asthma Severity

A machine that measures exhaled nitricoxide may help physicians assess asthmaseverity, helping them to better calculate theneed for inhaled corticosteroid medication.

The amount of nitric oxide in exhaled airis a sign of asthma, and higher levels ofnitric oxide indicate that the asthma is gettingworse. In the study, the researchersevaluated 46 individuals with asthma usingthe exhaled nitric oxide test and comparedthem with a group of 48 patients whoseasthma was examined using standardmeasurements (ie, peak flow testing).

All of the participants had been usinginhaled corticosteroids. Using both tests, theresearchers modified the dose of fluticasoneuntil the optimum dose for controlling asthmawas reached. Once achieved, the patientswere followed for 12 months. The final averagedose of fluticasone was 370 mcg for thenitric oxide group versus 641 mcg for thecontrol group. The results of the studyshowed that the rates of asthma exacerbationswere <1 per patient per year. The nitricoxide group, however, averaged 45% fewerexacerbations, compared with the controlgroup. The researchers said that nitric oxidemachines should be available within 3 years.(The findings were reported in the New EnglandJournal of Medicine, May 26, 2005.)