Association between ventilatory ratio and mortality in patients with acute respiratory distress syndrome and COVID 19: A multicenter, retrospective cohort study oleh Henry M. Parada-Gereda, Janneth M. Avendaño, Johana E. Melo, Claudia I. Ruiz, Margarita I. Castañeda, Jorge Medina-Parra, Ricardo Merchán-Chaverra, Dinia Corzzo, Daniel Molano-Franco, Joan Ramón Masclans