Early prone positioning does not improve the outcome of patients with mild pneumonia due to SARS-CoV-2: results from an open-label, randomised controlled trial (the EPCoT Study)

Background Prone positioning is routinely used among patients with COVID-19 requiring mechanical ventilation. However, its utility among spontaneously breathing patients is still debated. Methods In an open-label randomised controlled trial, we enrolled patients hospitalised with mild COVID-19 pneumonia, whose arterial oxygen tension to inspiratory oxygen fraction ratio (PaO2 /FIO2) was >200 mmHg and who did not require mechanical ventilation or continuous positive airway pressure at hospital admission. Patients were randomised 1:1 to prone positioning on top of standard of care (intervention group) versus standard of care only (controls). The primary composite outcome included death, mechanical ventilation, continuous positive airway pressure and PaO2 /FIO2 <200 mmHg; secondary outcomes were oxygen weaning and hospital discharge. Results A total of 61 subjects were enrolled, 29 adjudicated to prone positioning and 32 to the control group. By day 28, 24 out of 61 patients (39.3%) met the primary outcome: 16 because of a PaO2/FIO2 ratio <200 mmHg, five because of the need for continuous positive airway pressure and three because of the need for mechanical ventilation. Three patients died. Using an intention-to-treat approach, 15 out of 29 patients in the prone positioning group versus nine out of 32 controls met the primary outcome, corresponding to a significantly higher risk of progression among those randomised to prone positioning (HR 2.38, 95% CI 1.04–5.43; p=0.040). Using an as-treated approach, which included in the intervention group only patients who maintained prone positioning for ⩾3 h·day−1, no significant differences were found between the two groups (HR 1.77, 95% CI 0.79–3.94; p=0.165). Also, we did not find any statistically significant difference in terms of time to oxygen weaning or hospital discharge between study arms in any of the analyses conducted. Conclusions We observed no clinical benefit from prone positioning among spontaneously breathing patients with COVID-19 pneumonia requiring conventional oxygen therapy.