Outcomes of covid-19 patients treated with continuous positive airway pressure outside the intensive care unit

Aim: We aimed to characterise a large population of coronavirus disease 2019 (COVID-19) patients with moderate-to-severe hypoxaemic acute respiratory failure (ARF) receiving continuous positive airway pressure (CPAP) outside the intensive care unit (ICU), and to ascertain whether the duration of CPAP application increased the risk of mortality for patients requiring intubation. Methods: In this retrospective, multicentre cohort study, we included adult COVID-19 patients, treated with CPAP outside ICU for hypoxaemic ARF from 1 March to 15 April, 2020. We collected demographic and clinical data, including CPAP therapeutic goal, hospital length of stay and 60-day in-hospital mortality. Results: The study included 537 patients with a median (interquartile range (IQR) age of 69 (60–76) years. 391 (73%) were male. According to the pre-defined CPAP therapeutic goal, 397 (74%) patients were included in the full treatment subgroup, and 140 (26%) in the do not intubate (DNI) subgroup. Median (IQR) CPAP duration was 4 (1–8) days, while hospital length of stay was 16 (9–27) days. 60-day in-hospital mortality was 34% (95% CI 0.304–0.384%) overall, and 21% (95% CI 0.169–0.249%) and 73% (95% CI 0.648–0.787%) for full treatment and DNI subgroups, respectively. In the full treatment subgroup, inhospital mortality was 42% (95% CI 0.345–0.488%) for 180 (45%) CPAP failures requiring intubation, and 2% (95% CI 0.008–0.035%) for the remaining 217 (55%) patients who succeeded. Delaying intubation was associated with increased mortality (hazard ratio 1.093, 95% CI 1.010–1.184). Conclusions: We described a large population of COVID-19 patients treated with CPAP outside ICU. Intubation delay represents a risk factor for mortality. Further investigation is needed for early identification of CPAP failures.