Application of pulmonary function and fractional exhaled nitric oxide tests in the standardized management of bronchial asthma in children

Abstract:

Objective To investigate the changes of pulmonary function and fractional exhaled nitric oxide (FeNO) in the standardized treatment of bronchial asthma in children. Methods A total of 254 children who were newly diagnosed with acute exacerbation of bronchial asthma were selected as asthma group, and they were divided into two subgroups:asthma with concurrent rhinitis and asthma without concurrent rhinitis. All patients received the standardized management and treatment for one year. The pulmonary function parameters included forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), maximal mid-expiratory flow (MMEF), and mid-expiratory flow at 25%, 50%, and 75% of vital capacity (MEF25, MEF50, and MEF75). The FeNO levels were measured before treatment and at 3, 6, 9, and 12 months after treatment. Another 62 healthy children were selected as the control group, and the pulmonary function and FeNO levels were measured only once. Results During one year of standardized treatment, FEV1, PEF, MMEF, MEF25, MEF50, and MEF75 gradually increased, and FeNO levels gradually decreased (P < 0.05). Indicators of large airway function, such as FEV1 and PEF, almost returned to normal after 6 months of treatment; indicators of small airway function, such as MMEF, MEF25, MEF50, and MEF75 almost returned to normal after 9 months of treatment; there were no significant differences in the above indices between the asthma group and the control group after one year of treatment (P > 0.05). However, the asthma group had a significantly higher FeNO levels than the control group after one year of treatment (P < 0.05). The asthmatic patients with concurrent rhinitis had significantly higher FeNO levels than those without concurrent rhinitis before treatment and 3 months after treatment (P < 0.05). Before treatment, there was a significant negative correlation between FeNO levels and pulmonary function parameters (P < 0.05). Conclusions With the standardized treatment of bronchial asthma in children, pulmonary function parameters gradually increase and FeNO levels gradually decrease. The recovery of large airway function occurs earlier than the recovery of small airway function. Furthermore, the effect of rhinitis on airway responsiveness should be noted.