Prone positioning for patients intubated for severe acute respiratory distress syndrome (ARDS) secondary to COVID-19: a retrospective observational cohort study

Background The role of prone positioning in intubated subjects with acute respiratory distress syndrome caused by coronavirus disease 2019 (COVID-19) remains unclear. Methods We conducted an observational cohort study of intubated patients admitted to our academic medical centre intensive care unit with COVID-19 between March 18-31 2020. Exclusion criteria were pregnancy, reintubation and previous prone positioning at a referring hospital. Patients that were placed in the prone position were followed up until hospital discharge. The primary outcome was oxygenation assessed by arterial oxygen tension/fraction of inspired oxygen ratio (PaO2/FIO2). Secondary outcomes included PaO2/FIO2 ratio improvement ≥20%. Treatment failure of prone positioning was defined as death or requirement for extracorporeal membrane oxygenation (ECMO). Results Forty-two subjects (29 males; mean age:58.5 [12.7] years) were eligible for analysis. Nine subjects were placed in the prone position only once, with 25 requiring prone positioning on ≥3 occasions. 31/42 (74%) subjects survived to discharge, with 5 requiring ECMO; 11/42 (26.2%) subjects died. Following the first prone positioning session, mean (SD) PaO2/FIO2 ratio increased from 17.9kPa (7.2) to 28.2kPa (12.2) (p