Fig. 1.

Change in positive end-expiratory pressure (PEEP) in intensive care unit (ICU) and surgical patients over the past years. The practice of PEEP changed remarkably over the last 40 years in ICU patients. As in ICU patients with acute respiratory distress syndrome (ARDS) (red symbols), in ICU patients with uninjured lungs (blue symbols) and in surgery patients (green symbols) high PEEP is increasingly used, despite the lack of evidence. Data are (mean or median) levels of PEEP reported in observational studies, or in the control arms of randomized controlled trials (RCTs) versus the year of start of data collection, or year of publication if the latter was not presented. Abbreviations: ICU intensive care unit, PEEP positive end-expiratory pressure, RCTs randomized controlled trials