Application of fractional exhaled nitric oxide and nasal nitric oxide in the evaluation of asthma control

Abstract

Background Asthma is the most common chronic respiratory disease in childhood. Persistent chronic airway inflammation is a pathological feature of asthma, so the control of airway inflammation is particularly important in asthma treatment. In recent years, fractional exhaled nitric oxide (FeNO) and fractional nasally exhaled nitric oxide (FnNO) has been used in the evaluation of airway inflammation. Methods This was a retrospective study. This study retrospectively analyzed the clinical data of 88 patients with asthma who received treatment and follow-up at The First Hospital of Jilin University from 2019 to 2022. The inclusion criteria were as follows: a. all patients met the criteria for diagnosis of bronchial asthma14; b. chronic persistent asthma was treated with standard protocols for more than 3 months; and c. the patient was able to cooperate with lung ventilation function tests and FeNO and FnNO examination.All subjects were divided into a control group, a partial control group and a poor control group according to Childhood Asthma Control Test (C-ACT) scores. FeNO, FnNO, and pulmonary function were compared among the three groups. We also analyzed whether FeNO and FnNO were correlated with various indices of pulmonary function in patients with asthma. Results The level of asthma control was not affected by rhinitis attacks. The FeNO and FnNO values of the poor control group were significantly higher than those of the partial control group and the control group. As asthma control improved, forced vital capacity (FVC) showed a statistically significant increase. The FEV1, maximal expiratory flow at 50% of the FVC (MEF50%) and maximal midexpiratory flow (MMEF) levels in the poor control group were significantly lower than those in the partial control group and the control group, and the PEF level of the poor control group was significantly lower than that of the control group. FeNO and FnNO had no significant correlation with pulmonary function parameters. Conclusions FeNO and FnNO should be used to assess the level of control in patients with asthma. There is no significant correlation among FeNO, FnNO and various parameters of pulmonary function.