Best time for detecting experiment of fractional exhaled nitric oxide in young wheezing children / 中华实用儿科临床杂志

ABSTRACT

Objective To study the correlation between fractional exhaled nitric oxide (FeNO) and lung function in young children for acute attack of wheezing,and to compare the FeNO in different stages in order to explore the best suitable time for the experiment of FeNO in young children by the method of on-line tidal breathing.Methods Recurrent wheezing children aged 1-5 year old were selected who were underwent the test at lung function laboratory from January 2016 to March 2018,at Guangzhou Women and Children's Medical Center.The children aged less than 5 years old were detected for FeNO in both stages of acute exacerbation and 2 weeks after treatment,and the children aged less than 3 years were also detected for the tidal lung function in the acute exacerbation stage.According to time ratio of reaching tidal peak flow to total expiratory time(TPTEF/TE) and ratio of volume at tidal peak flow to total tidal volume (VPEF/VE),the children aged less than 3 years were divided into 4 groups (normal group,mild group,moderate group and severe group).Results The FeNO of the normal group [9.85 (5.17,19.62) ppb] and mild group[13.00 (7.00,23.30) ppb] were significantly higher than that of the severe group [3.10 (2.20,5.25)ppb],and the differences were statistically significant (all P ＜ 0.05).And there was a positive correlation between TPTEF/TE and FeNO(r =0.304,P ＜ 0.05),VPEF/VE and FeNO(r =0.320,P ＜ 0.05),tidal volume per kilogram (VT/kG) and FeNO(r =0.293,P ＜ 0.05)and a negative correlation between respiration rate(RR) and FeNO (r =-0.449,P ＜ 0.05).The FeNO in the stage of acute exacerbation was significantly lower than that in the stage of 2 weeks after treatment[(10.49± 8.49) ppb vs.(20.41 ± 9.13) ppb],and there was a significant difference among them(t =-5.79,P ＜ 0.01).Conclusions If researchers want to use the method of on-line breathing to test FeNO in young children with wheezing,they should choose the time of 2 weeks after treatment,and analyze the results combined with the lung function.