Aims and objectives: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) can cause acute respiratory failure (ARF) and death. We retrospectively analyzed for 1-year mortality and readmission rate according to the type of ARF in hospitalized patients for AECOPD.

Methods: We retrospectively reviewed the medical charts of hospitalized patients with COPD between 2016 and 2021 at two tertiary referral hospitals and ascertained the presence of ARF within 24 hours after admission. ARF was classified as type 1 (hypoxemic) and type 2 (hypercapnic).

Results: In total, 435 patients were enrolled, of which 170 had no ARF, 165 had type 1 ARF, and 100 had type 2 ARF. As compared with non-ARF group, the frequency of use of high-flow nasal cannula, non-invasive ventilation, steroids, intensive care unit (ICU) admissions, and in-hospital deaths was higher for those with ARF. Compared to type 1 ARF group, type 2 ARF group required more non-invasive ventilation use, and ICU admission. The type 1 ARF group had a 2.8-fold of 1-year mortality (hazard ratio [HR], 2.80; 95% confidence interval [CI], 1.09-7.18; P=0.031) and 1.6-fold higher risk of hospital readmission rate within 1 year after discharge (HR, 1.62; 95% CI, 1.076-2.46; P=0.021) compared with the non-ARF group.

Conclusions: Severe AECOPD patients with ARF had worse clinical outcomes than those without ARF. In particular, patients with type 1 ARF has a higher 1-year mortality and readmission rate than those without ARF.