Abstract:OBJECTIVE To explore the value of exhaled nitric oxide (FENO) in the diagnosis and treatment of bronchial asthma in children aged 4～9 years.METHODS 240 children aged 4～9 years with cough, chest tightness, and wheezing, who were admitted to our hospital from February 2014 to February 2016, were included in this study. Among them, 144 patients with bronchial asthma were group A, and the first diagnosis was One hundred and fifty patients in group I were treated with regular therapy and 39 patients in group II were treated with regular therapy and 96 patients with non-asthma group were in group B. The NIOX NO detector was used to detect FENO in each group. The GINA standard was used as the gold standard for diagnosis. The receiver operating curve (ROC) was plotted. The diagnostic value of FENO was evaluated by combining with the ROC curve, and the FENO diagnostic critical point was defined. Patients in group I were given drug treatment. They were treated with sullitide+swollenin and sultidi, respectively, and FENO and pulmonary function were measured before and after treatment with two different methods.RESULTS The FENO levels in the I, II, and B groups were compared with the predicted percentage of the first expiratory forced-vessel volume (FEV1%), P＜0.05; the area under the ROC curve was 0.897, and the optimal FeNO diagnostic critical point was 31.7 ppb. After treatment, FENO levels were significantly lower than before treatment, and FEV1% levels were significantly higher than before treatment, FEV1% and FENO levels between combination therapy and monotherapy were compared, CONCLUSION FeNO level has a higher diagnostic value for bronchial asthma in children aged 4～9 years, and can better evaluate the clinical treatment effect.