Awake prone positioning and oxygen therapy in patients with COVID-19: The APRONOX study

Perez-Nieto, O. R.; Escarraman-Martinez, D.; Guerrero-Gutierrez, M. A.; Zamarron-Lopez, E. I.; Mancilla-Galindo, J.; Kammar-Garcia, A.; Martinez-Camacho, M. A.; Deloya-Tomas, E.; Sanchez-Diaz, J. S.; Macias-Garcia, L. A.; Soriano-Orozco, R.; Cruz-Sanchez, G.; Salmeron-Gonzalez, J. D.; Toledo-Rivera, M. A.; Mata-Maqueda, I.; Morgado-Villasenor, L. A.; Martinez-Mazariegos, J. J.; Flores Ramirez, R.; Medina-Estrada, J. L.; Namendys-Silva, S. A.; Group, APRONOX

Purpose: The awake prone position (PP) strategy for patients with acute respiratory distress syndrome (ARDS) is a safe, simple, and cost-effective technique used to improve hypoxemia. We aimed to evaluate the relationship between awake PP (AP) and endotracheal intubation in patients with coronavirus disease (COVID-19). Methods: In this retrospective, multicentre observational study conducted between 1 May and 12 June 2020 in 27 hospitals in Mexico and Ecuador, non-intubated patients with COVID-19 managed with AP or awake supine positioning (AS) were included to evaluate intubation and mortality risk in AP patients through logistic regression models; multivariable adjustment, propensity score analyses, and E-values were calculated to limit confounding. A CART model with cross-validation was also built. This study was registered at https://clinicaltrials.gov/ct2/show/NCT04407468 Results: 827 non-intubated patients with COVID-19 in the AP (n=505) and AS (n=322) groups were included for analysis. Less patients in the AP group required endotracheal intubation (23.6% vs 40.4%) or died (20% vs 37.9%). AP was a protective factor for intubation even after multivariable adjustment (OR=0.39, 95%CI:0.28-0.56, p<0.0001, E-value=2.01), which prevailed after propensity score analysis (OR=0.32, 95%CI:0.21-0.49, p<0.0001, E-value=2.21), and mortality (adjusted OR=0.38, 95%CI:0.25-0.57, p<0.0001, E-value=1.98). The main variables associated with PP failure in AP patients were age, lower SpO2/FiO2, and management with a non-rebreather mask. In the CART model, only two variables were used: SpO2/FiO2 (F 97.7, p<0.001) and PP (X2 50.5, p<0.001), with an overall percentage of 75.2%. Conclusion: PP in awake hospitalised patients with COVID-19 is associated with a lower risk of intubation and mortality.