COVID-19: instruments for the allocation of mechanical ventilators: a narrative review - Santos, Marcelo José dos; Martins, Maristela Santini; Santana, Fabiana Lopes Pereira; Furtado, Maria Carolina Silvano Pacheco Corrêa; Miname, Fabiana Cristina Bazana Remédio; Pimentel, Rafael Rodrigo da Silva; Brito, Ágata Nunes; Schneider, Patrick; Santos, Edson Silva dos; Silva, Luciane Hupalo da (Critical Care, 2020)