The diagnostic value of fractional exhaled nitric oxide in occupational asthma and its correlation with pulmonary function

Abstract

Objective: To investigate the value of fractional exhaled nitric oxide (FeNO) in the diagnosis of occupational asthma (OA) , and analyze the correlation between FeNO and pulmonary function in patients with OA. Methods: In October 2019, clinical datas, including pulmonary function, FeNO and blood routine test of 64 workers who applied for the diagnosis of OA in January 2012 to October 2018 in our hospital were collected. The diagnostic value of FeNO in OA was evaluated, FeNO and pulmonary function in different degrees of OA were compared, and the correlations were analyzed. Results: The FeNO value of OA patients [ (58.4±13.1) ppb] was higher than non-OA patients[ (30.1±13.7) ppb] (P<0.05) . The FeNO value of patients with moderate OA [ (68.9±13.8) ppb] was higher than that of patients with mild OA[ (54.2±10.3) ppb] (P<0.05) . The area under the receiver operating characteristic (ROC) curve of FeNO in the diagnosis of OA was 0.9453 (95%CI: 0.8928-0.9978, P<0.05) , the optimal cut-off point is 47.5 ppb, and the sensitivity and specificity are 88.6% and 89.7% respectively. There was negative correlation between FeNO and FEV1% pred (r=-0.454, P<0.01) . Conclusion: FeNO has a clinical application value in the diagnosis of OA. It should be combined with pulmonary function index in practical work.