Background: Current knowledge about prognosis after intensive care for COPD exacerbation in patients with long-term oxygen therapy (LTOT) is limited.

Aims: To investigate survival after ICU admission for COPD exacerbation in patients with and without LTOT.

Material and methods: Nationwide observational cohort study including all first-time ICU admissions for COPD exacerbation in the Swedish Intensive Care Register 2008-2015. The National Quality Register for Respiratory Failure (Swedevox) provided data on LTOT. Mortality was traced through the Population Register.

Results: The cohort included 4828 patients (60% women) and 466 had LTOT before first ICU admission. LTOT patients were older (median 74 years (IQR 69-79) vs 72 years (IQR 66-78), p<0.001) and had higher simplified acute physiology score 3 (SAPS3) score; median 60 (IQR 54-68) vs 59 (IQR 52-66), p=0.008).

Mortality was higher for LTOT patients in the ICU (13.5% vs 7.5%; p<0.001) and at 30 days after ICU admission (37.8% vs 25.0%; p<0.001). In logistic regression adjusted for SAPS3 score and sex, LTOT was associated with increased 30-day mortality (OR 1.8; 95% CI 1.4-2.2).Median survival time from ICU admission was 3.2 months (IQR 0.2-17.7) for LTOT patients and 16.0 months (IQR 1.0-52.8) for patients without LTOT.