Prone positioning of non-intubated patients with COVID-19 - A Systematic Review and Meta-analysis

Purpose: Several studies have reported adopting prone positioning (PP) in non-intubated patients with COVID-19-related hypoxaemic respiratory failure. This systematic review and meta-analysis evaluated the impact of PP on oxygenation and clinical outcomes. Methods: We searched PubMed, Embase and COVID-19 living systematic review from December1st 2019 to July23rd 2020. We included studies that reported using PP in hypoxaemic, non-intubated adult COVID-19 patients. Primary outcome measure was the weighted mean difference (MD) in oxygenation parameters (PaO2/FiO2, PaO2 or SpO2) pre and post-PP. Results: Fifteen single arm observational studies reporting PP in 449 patients were included. Substantial heterogeneity was noted in terms of, location within hospital where PP was instituted, respiratory supports, frequency and duration of PP. Significant improvement in oxygenation was reported post-PP: PaO2/FiO2, (MD 37.6, 95%CI 18.8, 56.5); PaO2, , (MD 30.4 mmHg, 95%CI 10.9, 49.9); and SpO2, (MD 5.8%, 95%CI 3.7, 7.9). Patients with a pre-PP PaO2/FiO2 [≤]150 experienced greater oxygenation improvements compared with those with a pre-PP PaO2/FiO2 >150 (MD 40.5, 95%CI -3.5, 84.6) vs. 37, 95%CI 17.1, 56.9). Respiratory rate decreased post-PP (MD -2.9, 95%CI -5.4, -0.4). Overall intubation and mortality rates were 21% (90/426) and 26% (101/390) respectively. No major adverse events were reported. Conclusions: Despite significant variability in frequency and duration of PP and respiratory supports, PP was associated with improvements in oxygenation parameters without any reported serious adverse events. Major limitation being lack of control arm and adjustment for confounders. Clinical trials are required to determine the effect of awake PP on patient-centred outcomes.