Response to prone positioning in COVID-19 patients with acute respiratory distress syndrome: a retrospective observational study

Background COVID-19 pneumonia and respiratory failure are the leading causes of death in COVID-19 patients. Prone positioning was hypothesized to improve oxygenation in ARDS patients and is being studied in COVID-19, but the current evidence is still unclear regarding survival and hospitalization. We aimed to investigate the effect of prone positioning on oxygenation in patients with COVID-19 pneumonia and ARDS and to examine the factors associated with better/worse outcomes. Methods A retrospective record-based cohort study included all confirmed COVID-19 patients with pneumonia and ARDS who underwent prone positioning admitted to King Fahad Hospital, Medina, Saudi Arabia, during 2020-2021. Results This study included 75 cases (mean age 60.3 +/- 15.7 year, 50 (66.7%) males), and all fulfilled the definition of ARDS. There was a significant improvement in oxygenation (PaO2 and PaO2/FIO2) following prone positioning (53.5 +/- 6.8 vs. 60.4 +/- 8.2 mmHg, p < 0.001 for PaO2 supine and prone and 120.3 +/- 35 vs. 138 +/- 40.2, p < 0.001 for PaO2/FIO2 supine and prone respectively). There was no significant difference in age, gender, smoking, or number of comorbidities between survivors and non-survivors. Survivors had significantly higher baseline PaO2 (p 0.018) and PF ratio (p 0.001) compared to non-survivors. They had also less severe inflammation and organ damage observed as significantly lower ferritin (p 0.001), D-dimer (p 0.026), aspartate aminotransferase (p 0.02), urea (p 0.032), creatinine (p 0.001), and higher platelet counts (p 0.001). Intubation and high-moderate comorbidity risk categories were associated with non-survival (p 0.001 and p 0.014, respectively). Conclusion Prone positioning is useful in the improvement of oxygenation in intubated and awake patients with COVID-19 pneumonia and ARDS. Intubation and high comorbidity risk categories were associated with non-survival.