Use of CPAP for Management of Moderate-to-severe AHRF in Covid-19 Patients: a Retrospective Observational Study in the Latest Pandemic Waves

Background: In a preliminary study during the first COVID-19 pandemic wave, we reported a high rate of success with continuous positive airway pressure (CPAP) in preventing death and invasive mechanical ventilation (IMV). That study, however, was too small to identify risk factors for mortality, barotrauma and impact on subsequent IMV. Thus, we re-evaluated the efficacy of the same CPAP protocol in a larger series of patients during second and third pandemic waves. Methods: 281 COVID-19 patients with moderate-to-severe acute hypoxemic respiratory failure (158 full-code and 123 do-not-intubate, DNI), were managed with high-flow CPAP early in their hospitalization. IMV was considered after 4 days of unsuccessful CPAP. Results: The overall recovery rate from respiratory failure was 50% in the DNI and 89% in the full-code group. Among the latter, 71% recovered with CPAP only, 3% died under CPAP and 26% were intubated after a median CPAP time of 7 days (IQR: 5-12 days). Of the patients who were intubated, 68% recovered and were discharged from the hospital within 28 days. Barotrauma occurred during CPAP in <4% of patients. Age (OR=1.128; p