To explore application values of bronchial provocation test (BPT) in the management of childhood asthma.

A total of 39 asthmatic children treated in outpatient clinic of Hebei Children′s Hospital as clinical remission, and reached a well-controlled level for at least 1 year from May 2018 to October 2019, were selected as research subjects. According to small airway function, they were divided into research group (n=11, decreased small airway function) and control group (n=28, normal small airway function). Their clinical data were analyzed retrospectively, including lung function, the BPT results of methacholine by Astograph, and control level of asthma in different conditions during the follow-up period of 6 months after BPT. Independent-samples t test and Fisher exact probability method were used to statistically compare the BPT positive rate and basic airway resistance between two groups of children, as well as the asthma control level of children under different conditions. This study was approved by the Medical Ethics Committee of Hebei Children′s Hospital (Approval No. Medical Research Ethics Approval No. 120). All children and their guardians were informed and agreed at the time of enrollment.

①There was no significant difference in positive rate of BPT between two groups of children (P>0.05). The basic airway resistance of children in research group was (6.21±1.69) cmH₂O/(L·s) (1 cmH₂O=0.098 kPa), which was significantly higher than that of (4.97±1.42) cmH₂O/(L·s) in control group, and the difference was statistically significant (t=2.324, P=0.026). ② Among 28 children with BPT positive, the recurrence rate of asthma in children who discontinued treatment was 64.3% (9/14), which was significantly higher than that of 21.4%(3/14) in children who continued the original treatment, and the difference was statistically significant (P=0.027); The recurrence rate of asthma in BPT positive children who discontinued treatment (64.3%, 9/14) was significantly higher than that of 9.1%(1/11) in BPT negative children who discontinued treatment, and the difference was statistically significant (P=0.007).

For asthmatic children who are in clinical remission and have reached a well-controlled level, it is recommended to monitor their airway responsiveness while monitoring their lung function. For BPT positive asthmatic children, it is recommended to postpone the downgrading of drug or stop the treatment in order to control the asthma attack better.