Control maintenance can be predicted by exhaled NO monitoring in asthmatic patients

SummaryBackgroundFractional exhaled nitric oxide (FENO) is a marker of airway inflammation in asthma. Monitoring of such inflammation is currently not included in asthma guidelines and remains controversial. The hypothesis underlying the present study was that, FENO could help assessing asthma control and, therefore, improve its management, by predicting loss of control in asthmatics.MethodsA total of 90 adult asthmatics were included in the study. Asthma control was evaluated according to ACQ. All patients underwent FENO by chemiluminescent (EndoNO) and hand-held (MINO) devices, followed by lung function testing.ResultsMINO was accurate as compared to EndoNO. FENO was significantly increased in uncontrolled as compared to controlled asthmatics using both devices. FENO measurement was able to predict control maintenance in controlled asthmatics in the absence of any change in their treatment. Indeed, using cut-off values of 31 and 40 ppb, the negative predictive values were 95 and 97% for EndoNO and MINO, respectively. EndoNO and MINO were also able to assess asthma control, although to a lesser extent.ConclusionsThese findings suggest that FENO can predict the persistence of asthma control in controlled patients and may now be used in asthma management since it can accurately be measured by means of hand-held devices.