Abstract: Objective To explore and analyze the effect of doxofylline on the number of eosinophils in blood during acute exacerbation of chronic bronchitis. Methods From January 2017 to December 2022,82 patients with acute attack of chronic bronchitis treated in the Fifth People's Hospital of Wujiang District, Suzhou were selected as the study subjects. According to a 1:1 random number table method, the patients were divided into the observation group of 41 cases and the control group of 41 cases. Both groups were treated with expectorant, anti infection. The control group were treated with compound Ipratropium bromide, while the observation group were treated with doxofylline on top of the control group. Both the doxophylline group and the control group were treated for 7 d to detect the total response rate of patients after 7 d of treatment, the duration of disappearance time of dyspnea, cough, sputum, lung rales, the count of FEV₁/ FVC, the level of FEV₁ and peripheral blood acidophilia granulocytic content were compared before and 7 d after treatment in each group and between the groups. Results After 7 days of treatment, the total effective rate of the study group was higher than that of the control group, The difference is statistically significant (P<0.05). The duration of disappearance of symptoms such as dyspnea, cough and phlegm, and lung rales in the observation group were significantly reduced compared to the control group (P<0.05). The percentage of forced expiratory volume (FEV) in the first second to forced vital capacity( FEV₁/ FVC) and FEV1 in both groups after 7 days of treatment were significantly higher than those before treatment (P<0.05). The FEV₁/ FVC and forced expiratory volume in the first second in the observation group after 7 days of treatment were significantly higher than those in the control group (P<0.05). The content of eosinophils in the peripheral blood of both groups after 7 days of treatment were significantly lower than before treatment (P<0.05), while the content of eosinophils in the peripheral blood of the observation group after 7 days of treatment were significantly lower than that of the control group (P<0.05). Conclusion The application of doxofylline in acute exacerbation of chronic bronchitis can promote the improvement of clinical symptoms, improve treatment effectiveness, improve lung function, and reduce the content of eosinophils in the patient's peripheral blood.

Key words: doxophylline, chronic bronchitis, acute attack, lung function, peripheral blood, eosinophils, compound Ipratropium bromide