Prognostic classification based on P/F and PEEP in invasively ventilated ICU patients with hypoxemia-insights from the MARS study.

Background: Outcome prediction in patients with acute respiratory distress syndrome (ARDS) greatly improves when patients are reclassified based on predefined arterial oxygen partial pressure to fractional inspired oxygen ratios (PaO/FiO) and positive end-expiratory pressure (PEEP) cutoffs 24 h after the initial ARDS diagnosis. The aim of this study was to test whether outcome prediction improves when patients are reclassified based on predefined PaO/FiO and PEEP cutoffs 24 h after development of mild hypoxemia while not having ARDS.

Methods: Post hoc analysis of a large prospective, multicenter, observational study that ran in the ICUs of two academic hospitals in the Netherlands between January 2011 and December 2013.