Author Affiliations: Sunnybrook Health Sciences Centre, Program in Trauma, Emergency, and Critical Care, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
Acute lung injury (ALI) is a common, lethal, and complex syndrome. Estimates of attributable mortality from ALI or its more severe form, acute respiratory distress syndrome (ARDS), in the United States place it above asthma and human immunodeficiency virus infection as a cause of death.1 The current mortality of 35% associated with ALI is roughly 3-fold higher than that associated with ST-segment elevation myocardial infarction.2 Most of the salient features of ARDS, including the therapeutic use of positive end-expiratory pressure (PEEP), were described by Ashbaugh et al3 in their classic description of the syndrome: “ventilation without positive end-expiratory pressure resulted in immediate hypoxaemia. . . . Collapsed alveoli require greater pressures for reopening, thus explaining the notable loss of compliance. Positive end-expiratory pressure would theoretically prevent complete collapse and improve oxygenation by maintaining alveolar ventilation.”
Rubenfeld GD. How Much PEEP in Acute Lung Injury. JAMA. 2010;303(9):883-884. doi:10.1001/jama.2010.226