Analysis of clinical characteristics and different detection methods in asthmatic children with persistent small airway airflow limitation

WANG Xia; GONG Cai-hui; LIN Ying; QIN Jiang-jiao; LV Ying; TIAN Dai-yin; FU Zhou; LIU Sha

doi:10.19538/j.ek2025020612

Abstract：Objective To explore the clinical characteristics of children with persistent small airway airflow limitation and the sensitivity of different small airway assessment methods.Methods Asthmatic children aged 9 to 18 years who were in clinical remission with small airway airflow limitation suggested by routine pulmonary function tests for more than 2 times in the past year,who visited the outpatient clinic of our hospital from February 2023 to April 2024,were enrolled to summarize the clinical characteristics.Chest high-resolution CT(HRCT)was used to compare the ratio of small airway wall area and thickness.Meanwhile,routine pulmonary function tests,pulse oscillation(IOS),plethysmography and exhaled nitric oxide(FeNO)were perfected,and the examination results and their correlation were analyzed.Results A total of 53 children were included,including 30 males and 23 females,aged 10(10,11)years.8 patients(15.09％)had a family history of asthma,and 27 patients(50.94％)had a clear history of allergy.51 cases(96.23％)were treated according to the doctor's advice,and 6 cases(11.32％)had definite acute attack of asthma in the past 1 year.In the past year,asthma control drug were reducted in 18 cases(33.96％),including 3 cases of recurrent symptoms(16.67％),cough and wheezing occurred in 4 from 9 cases who underwent drug withdrawal(44.44％).Pulmonary function,FeNO and HRCT were also tested in 36 children.The FEF75 and MMEF values of 36(100％)children were lower than the lower limit of normal value,and the HRCT results showed that the ratio of airway wall area(WA％)and thickness ratio(T/D)were significantly increased in this group.The results of plethysmography showed that only 2 cases had RV and RV/TLC Z-scores greater than 1.64.The IOS results showed only 1 case indicated peripheral airway obstruction.FeNO detection showed only 4 cases with elevated FeNO200 and CaNO.Conclusion Asthmatic children with standard treatment and clinical remission but with persistent small airway airflow limitation may have developed small airway remodeling and have a higher rate of recurrent symptoms after drug withdrawal.The sensitivity of small airway dysfunction indicated by routine ventilation was superior to IOS,plethysmography and FeNO.