Introduction: Severe acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a significant event that results in substantial mortality.

Objectives: We evaluated the effectiveness of the high flow nasal cannulae (HFNC) therapy in severe AECOPD with moderate hypercapnic acute respiratory failure (ARF) compared to non-invasive ventilation (NIV).

Methods: The prospective observational trial was performed to compare the effectiveness between the HFNC and NIV in severe AECOPD with moderate hypercapnic ARF. The end point was the intubation rate and 30-day mortality.

Results: Ninety-two AECOPD patients enrolled during study periods. The median age was 73 (66.5-79) years, and 57 patients (64.8%) were male. Forty-four patients were assigned to HFNC, and 44 patients were assigned to NIV. The intubation rate at day 30 was 25.0% in the HFNC group and 27.3% in the NIV group (P = .857), and the 30-day mortality was 15.9% in the HFNC group and 18.2% in the NIV group (P = .845). The pH (7.38 ± 0.59 vs 7.36 ± 0.10, P = .295), PaO₂ (82.2 ± 24.9 vs 81.6 ± 21.7 mm Hg, P = .899) and PaCO₂ (46.8 ± 15.2 vs 51.7 ± 17.2 mm Hg, P = .160) after 6 hours and the pH (7.39 ± 0.07 vs 7.39 ± 0.08, P = .743), PaO₂ (84.3 ± 18.5 vs 84.7 ± 23.2 mm Hg, P = .934) and PaCO₂ (47.0 ± 16.0 vs 49.6 ± 13.7 mm Hg, P = .422) after 24 hours were not significantly different.

Conclusion: There was no difference of the 30-day mortality and intubation rate between HFNC and NIV groups.