The Effect of Prone and Awake Prone Position Duration on the Outcomes of COVID-19 Patients: A Systematic Review and Meta-Analysis

Introduction: Prone positioning (PP) and awake PP has been reported to reduce the mortality of patients with Coronavirus Disease 2019 (COVID-19). However, the role of PP duration in this process is still unclear. Methods: PubMed, Embase, Web of Science and CNKI databases were searched up to January 2022.The primary outcomes were the mortality and PaO2/FiO2 ratio. The secondary outcome was the length of hospital stay and endotracheal intubation. Results: Thirty-six eligible studies (n=5661) were included. Compared with control group, PP significantly improved the PaO2/FiO2 ratio (MD=39.26, 95% CI=27.91 to 50.61, P <0.00001) , reduced mortality (OR=0.58, 95% CI=0.39 to 0.87, P =0.009) and the endotracheal intubation rate (OR=0.57, 95% CI=0.38 to 0.85, P = 0.005) in COVID-19 patients. PP reduce the mortality of non-intubated COVID-19 patients when the PP duration exceeds 8h/day(OR=0.39, 95% CI=0.21 to 0.74, P = 0.004), Moreover, awake PP were associated with lower incidence of mortality (OR=0.57, 95% CI=0.38 to 0.91, P =0.02) and endotracheal intubation (OR=0.67, 95% CI=0.44 to 1.00, P =0.05). Significant difference was noted in the incidence of mortality when awake PP duration more than 6h/day(OR=0.27, 95% CI=0.17 to 0.43, P <0.00001). Conclusion: PP significantly improved the PaO2/FiO2 ratio, reduced mortality and the endotracheal intubation rate among COVID-19 patients. The mortality of non-intubated COVID-19 patients decreased when PP duration more than 8h/day. Awake PP reduced mortality and endotracheal intubation in COVID-19 patients. Significant difference was noted in the incidence of mortality when awake PP duration more than 6h/day. Funding: Xi'an Medical College Basic and transformation research innovation team of respiratory and critical diseases.Declaration of Interest: None to declare.