Exhaled Nitric Oxide Predicts Asthma Exacerbation

Abstract

The fraction of exhaled nitric oxide (FeNO) is elevated in asthmatics compared to normal subjects. Many studies have demonstrated that FeNO correlates with other markers of airway inflammation. The purpose of this study was to assess the clinical utility of routine monitoring of FeNO in determining its ability to predict future asthma exacerbations compared with other standard clinical measures of spirometry, peak flows, quality of life score, medication usage, and symptoms. A convenience sample of 22 patients with moderate and severe-persistent asthma in the University of New Mexico Adult Asthma Clinic were evaluated during a routine clinic visit and then noted whether they had an exacerbation within 2 weeks of the initial appointment. Those with an exacerbation had a higher mean FeNO (29.67 ppb +/- 14.48) compared to those who did not (12.92 ppb +/- 5.17), p = 0.002. A nominal logistic regression model to determine those variables that predict asthma exacerbation found that FeNO was the only significant predictor, p = 0.03. Thus, FeNO appears to be a clinically useful tool to assess disease control in this population.

Human exhaled breath analysis

“…23 With the appearance of cheaper portable handheld devices based on electrochemical sensing on the market, the possibility was contemplated to perform serial measurements to monitor disease activity and to steer asthma control, 24 especially because it was demonstrated that the increase of FeNO precedes the decrease in peak expiratory flow rates. 25 Another lucrative possibility is to titrate the optimal maintenance dose of inhaled steroids. 26 Taken together, these applications held the promise to use FeNO to guide asthma management.…”

A water extract of Samchulkunbi-tang attenuates airway inflammation by inhibiting inos and MMP-9 activities in an ovalbumin-induced murine asthma model

“…Measurement of exhaled NO has been suggested as helpful for monitoring airway inflammation in asthma, especially in cases of exacerbated asthma [9]. Another important aspect of asthma is that the matrix metalloproteinase-9 (MMP-9) level increases significantly in the bronchoalveolar lavage fluid (BALF), blood, and sputum of people with asthma [10].…”

Role of inducible nitric oxide synthase on the development of virus-associated asthma exacerbation which is dependent on Th1 and Th17 cell responses

“…The NO levels in the airways are increased in asthma animal models, as well as in patients with asthma (Kharitonov et al, 1995;Weicker et al, 2001). Measurement of exhaled NO has been suggested as being helpful in the monitoring of airway inflammation in asthma, especially in the case of exacerbated asthma (Harkins et al, 2004). However, the role of NO or NOS-mediated effects in the development of asthma exacerbation during viral infections remains controversial.…”