Abstract: Objective To explore the effects of high-flow nasal cannula oxygen therapy on blood gas indexes, pulmonary function in chronic obstructive pulmonary disease (COPD) patients complicated with respiratory failure, and to explore the complications and long-term effect. Methods A total of 82 subjects were selected in our hospital from January 2017 to May 2020 and divided into observation group (n=42) and control group (n=40). The patients in observation group received high-flow nasal cannula oxygen therapy, and the patients in control group were treated with non-invasive positive pressure ventilation therapy. The blood gas indexes, pulmonary function, effective rate and the complications after 3 days of treatment and the prognosis after 6 months of treatment were compared between the two groups. Results After 3 days of treatment, the levels of arterial partial pressure of oxygen (PaO₂), forced expiratory volume in 1 s (FEV1), FEV1% predicted(FEV1% pred), forced vital capacity (FVC)% predicted(FVC% pred), FEV1/FVC in observation group were higher than those in control group (P<0.05), while the level of partial pressure of carbon dioxide in artery (PaCO₂) was lower than that in control group(P<0.05). The effective rate of observation group (92.85%) was higher than that of control group (57.50%). There was no significant difference in the incidence rate of complications between the two groups(P>0.05). The 6-minute walk distance (6MWD) and the score of modified British medical research council (mMRC)were higher, while the score of COPD assessment test (CAT), Borg score and BODE index were lower than those in control group after 6 months of follow-up(P<0.05). Conclusions High-flow nasal cannula oxygen therapy can improve the blood gas indicators, pulmonary function and outcome, which has a significant clinical application value.

Key words: chronic obstructive pulmonary disease, respiratory failure, high-flow nasal cannula oxygen therapy, blood gas indicator, pulmonary function