The usefulness of exhaled nitric oxide in monitoring of treatment in patients with severe asthma

Introduction. The assessment of exhaled nitric oxide (FENO) is a simple and noninvasive diagnostic test. Reports concerning the usefulness of exhaled nitric oxide determination for monitoring treatment in asthmatic patients are not unequivocal. Aim. The aim of this study was the assessment of usefulness of exhaled nitric oxide measurements in long term treatment in asthmatic patients who experienced periodic loss of control or aggravation of asthma symptoms. Material and methods. The study was conducted in a group of 22 patients suffering from severe allergic asthma, whose treatment was monitored by FENO measurement for 6 months. The end point of this study was assessment of FENO variable in case of loss of control/exacerbation of asthma. Results. Among 15 patients treated with high doses of inhaled glucocorticosteroids, there were 16 episodes of asthma exacerbations, of which 13 (81%) were associated with significant increase of FENO concentration. Among 7 patients treated with oral glucocorticosteroids, there were 8 episodes of loss of control/asthma exacerbations, of which 5 (62.5%) were associated with significant increase of FENO concentration. Conclusions. The results of this study indicate that FENO measurements may be useful in monitoring the course of asthma and assessment of situations associated with losing of control and exacerbation of the disease.