Abstract:Objective To explore the clinical value of pulmonary function combined with fractional exhaled nitric oxide (FeNO) in the diagnosis and treatment of infantile small airway lesion. Methods A total of 480 infants with small airway lesion diagnosed comprehensively by bronchial provocation test (BPT),bronchoscopy,high-resolution CT (HRCT) and treated from June 2018 to June 2019 were included as observation group,and 480 infants without small airway lesion were served as control group in the same time.The results of pulmonary function indexes (FEV₁%,TPTEF/TE,VPTEF/VE,Ti/Te,PEF%) and FeNO were observed and compared between two groups and also compared before and after treatment in observation group.Furthermore,the diagnostic efficacy of pulmonary function combined with FeNO versus BPT was observed. Results The levels of FEV₁%,TPTEF/TE,VPTEF/VE,PEF% in observation group were significantly lower than those in control group(P＜0.01,P<0.05),and level of FeNO was higher than that in control group［(31.92±6.71)ppb vs(19.38±2.61)ppb,P=0.007］;Compared with before treatment,the levels of FEV₁%,TPTEF/TE,VPTEF/VE,PEF% increased significantly (P＜0.01,P<0.05),and level of FeNO decreased ［(16.64±3.23)ppb vs(31.92±6.71)ppb,P=0.004］ after treatment in observation group.Based on the comprehensive diagnosis results of BPT,bronchoscope and HRCT,the specificity (93.75% vs 77.08%,P=0.021),accuracy (92.71% vs 81.25%,P=0.018),positive predictive value (93.62% vs 78.85%,P=0.035) of pulmonary function combined with FeNO were significantly higher than those of BPT. Conclusion In the diagnosis and treatment of infants with small airway diseases,pulmonary function combined with FeNO can provide reliable guidance parameters and have a higher clinical application value.