Exhaled nitric oxide as a predictor of the effectiveness of basic therapy for bronchial asthma in children
Background: The article discusses the predictive ability of monitoring nitric oxide in exhaled air relative to the level of control and the likelihood of developing exacerbations of bronchial asthma in children with basic therapy. According to many researchers, nitric oxide in exhaled air today is one of the markers of allergic inflammation of the respiratory tract, the assessment of which is proposed to be used as a criterion for both the diagnosis of asthma and the adequacy of the basic therapy. The aim of the study: To evaluate the predictive ability of monthly monitoring of nitric oxide in exhaled air regarding the achievement of control and the possible development of exacerbations in children with uncontrolled bronchial asthma with increased basic therapy. Materials and methods: There were assessed FeNO monthly levels in expired air (the portable NObreath nitric oxide analyzer – Bedfont Scientific.Ltd., UK) in 111 children (mean age 13.8±2.1 years) with asthma. All patients were on basic therapy and at the time of inclusion in the study were transferred to stage 3 (GINA, 2018) asthma therapy. The ACQ-5 questionnaire was used to record asthma control levels monthly. Depending on the initial FeNO level, 2 subgroups of patients were distinguished: 1 subgroup (n = 50), FeNO=36-49 ppb; 2 subgroup (n = 61), FeNO≥50 ppb. The obtained data were processed using ROC analysis within each subgroup and in the general cohort of patients. Results: The initial FeNO level does not have a prognostic ability to assess asthma control after 3 months of therapy and the development of asthma exacerbation during this time. Monitoring of nitric oxide level after 1 month allows us to predict the development of exacerbation of asthma, and after 2 months – as the development of exacerbation of asthma, and achieve control of asthma by 3 months of observation. The predictive ability to monitor FeNO was significant in subgroup 2. Conclusion: FeNO monitoring can be used to make decisions about changing basic asthma therapy in individual patient groups. Further studies are needed to assess the prognostic value of the dynamic control of FeNO in children with asthma.