Fig. 1.

Evidence-based decision-making flow chart for patients with ARDS requiring treatment using PEEP, according to patient physiological readouts. The approach we use to set up PEEP is applied either to patients in a supine position or to those with moderate-to-severe ARDS and prone positioning. Each step lasts normally 10 to 30 min. The area in light blue indicates that FiO₂ remains constant throughout the steps. After PEEP titration FiO₂ can be decreased (or increased) to target normoxia. Pre-existing barotrauma and (according to some authors) elevated intracranial pressure should discourage from application of high PEEP. Abbreviations and symbols: ARDS, acute respiratory distress syndrome; C_RS, compliance of the respiratory system; CW, chest wall; EIT, electrical impedance tomography; FiO₂, inspiratory oxygen fraction; PEEP, positive end-expiratory pressure; Pes, esophageal pressure; RM, recruitment maneuver; RV, right ventricle; US, ultrasound; ↑, increase; ↓, decrease; =, equal