Awake prone positioning in non-intubated patients with acute hypoxemic respiratory failure due to COVID-19: A systematic review of proportional outcomes comparing observational studies with and without awake prone positioning in the setting of COVID-19

International audience; Background Awake prone positioning (APP) has been advocated to improve oxygenation and prevent intubations of patients with acute hypoxemic respiratory failure due to coronavirus disease 2019 (COVID-19). This paper aims to synthesize the available evidence on the efficacy of APP.Methods: We performed a systematic review of proportional outcomes from observational studies to compare intubation rate in patients treated with APP or with standard care.Results: A total of 46 published and 4 unpublished observational studies that included 2994 patients were included, of which 921 patients were managed with APP, and 870 patients were managed with usual care. APP was associated with significant improvement of oxygenation parameters in 381 cases of 19 studies that reported this outcome. Among the 41 studies assessing intubation rates (870 patients treated with APP, and 852 patients treated with usual care), the intubation rate was 27%(95%CI, 19 to 37%), as compared to 30%(95%CI, 20 to 42%)(p=0.71), even when duration of application, use of adjunctive respiratory assist device (high flow nasal cannula or non-invasive ventilation) and severity of oxygenation deficit were taken into account. There appeared to be a trend toward improved mortality when treated with APP was compared with usual care (11% v.s. 22%), which was not statistically significant.Conclusions: APP was associated with improvement of oxygenation but did not reduce the intubation rate in patients with acute respiratory failure due to COVID-19. This finding is limited by the high heterogeneity and the observational nature of included studies. Randomized controlled clinical studies are needed to definitively assess whether APP could improve key outcome such as intubation and mortality rate in these patients.