Objective To observe the effects of indacaterol/glycopyrronium (IND/GLY) versus salmeterol/fluticasone (SFC) on pulmonary function, blood gas indexes and serum levels of inflammatory factors in patients with moderate to severe chronic obstructive pulmonary disease (COPD).

Methods A total of 120 patients with moderate to severe COPD were randomly divided into experimental group and control group using a random number table method, with 60 patients in each group. All the patients were given usual care after enrollment, the experimental group received IND/GLY treatment on the basis of routine treatment, and the control group received SFC treatment on the basis of routine treatment. All the patients in the two groups were continuously treated for 3 months. The response rate, pulmonary function, blood gas indexes, serum levels of inflammatory factors and incidence of adverse reactions were compared between the two groups before and after treatment.

Results After treatment, the total effective rate of the experimental group was 91.67%, which was higher than 75.00% of the control group, and the difference was statistically significant (P < 0.05). After treatment, the first-second forced expiratory volume (FEV₁), forced vital capacity (FVC) and the ratio of forced expiratory volume to forced vital capacity (FEV₁/FVC) of the experimental group and the control group were all higher than before treatment, and the improvement of various pulmonary function indicators of the experimental group was better than that of the control group (P < 0.05). After treatment, the partial pressure of arterial blood oxygenp_a(O₂), partial pressure of arterial blood carbon dioxidep_a(CO₂)and arterial blood oxygen saturation(SaO₂) of the experimental group and the control group were all improved compared with before treatment, and the improvement of various blood gas indexes of the experimental group was better than that of the control group (P < 0.05). After treatment, the levels of interleukin-6 (IL-6), interleukin-8 (IL-8), hypersensitive C-reactive protein (hs-CRP) and tumor necrosis factor-α (TNF-α) in the experimental group and the control group were lower than before treatment, and the levels of serum inflammatory factors in the experimental group were lower than those in the control group (P < 0.05). During the follow-up period, the incidence of adverse drug reactions in the experimental group was 20.00%, which showed no difference when compared with 21.67% in the control group (P>0.05).

Conclusion Compared with SFC, IND/GLY can significantly improve pulmonary function, blood gas indexes and serum inflammatory factors levels in patients with moderate to severe COPD. This study can provide references for clinicians for selection of individual drugs for treatment in patients with COPD.