Use of CPAP as an alternative to the apnea test during the determination of brain death in hypoxemic patients. Report of two cases. - Westphal, Glauco Adrieno; Fernandes, Veviani; Westphal, Verônica; Cangussu Fonseca, Jessica; Rodrigues da Silva, Luciano; dos Santos Valiatti, Jorge Luis (Revista Brasileira de Terapia Intensiva, 2020)