Study On The Value Of Bronchodilation Test In Asthmatic Children With Normal FEV₁,FVC And FEV₁/FVC

Bacground:Bronchodilation test are commonly used tools for the diagnosis and monitoring of bronchial asthma in children.The pulmonary function of asthmatic children is mainly obstructive ventilation dysfunction,which is reversible,but some children have normal baseline lung function,and the bronchodilation test still shows positive results.Objective:To evaluate the positive rate of bronchodilation test in asthmatic children with normal FEV1,FVC,FEV1/FVC,and improve the recognition of the importance of bronchodilation test with normal FEV1,FVC and FEV1/FVC.Methods:Children with asthma diagnosed in the outpatient clinic of Shandong Provincial Hospital from September 2018 to August 2019,aged 5-14 years,can be cooperate with pulmonary function and bronchodilation test,at the same time meet the quality control standars.Perform bronchodilation test on children with normal FEV1,FVC,and FEV1/FVC pulmonary function data of children,count the bronchodilation test positive rate and analyze the status of small airway function.Results:A total of 1631 asthmatic children were included in this study,including 1414 children with normal pulmonary function and 217 children with small airway dysfunction.Fifteen minutes after inhaling bronchodilator,127 children with bronchodilation test positive,accounting for 7.79%,87 males and 40 females,among them,62 children with small airway dysfunction were bronchodilation test positive.The improvement rate of FEV1 ranged from 8.0%to 11.9%in 132 cases(8.09%).The pre-bronchodilator FEV1 accounted for 98.51%±10.29%of the predicted value,after inhalation of terbutaline sulfate for 15 minutes,the improvement rate was 13.5%(12.50%,16.20%).The FVC,FEF50,FEF75 and MMEF pre-bronchodilator percentage of the predicted value accounted for 99.0%(92.2%,107.5%),68.2%(61.7%,82.3%),53.8%(43.1%,64.6%),65.9%(58.2%,78.4%),after inhalation of terbutaline sulfate for 15 minutes,the improvement rates were 5.7%(2.9%,10.7%),40.1%(28.3%,54.9%),66.5%(42.5%,93.8%),48.4%(34.8%,58.2%).The improvement rate of FVC,FEF50,FEF75 and MMAEF was negatively correlated with their baseline value.The improvement rate of FEV1 was not significantly related with the basic value of FEV1;The improvement rate of FEV1 was negatively correlated with the basic value of MMEF.Conclusion:There are 7.79%of asthmatic children had positive bronchodilation test,in the normal range of FEV1,FVC and FEV1/FVC.It is recommended to improve the bronchodilation test as much as possible for the diagnosis and follow-up of children with typical or atypical asthma to confirm the diagnosis and obtain the current personal best results.At the same time,asthma condition and control level were evaluated comprehensively in combination with small airway function.