Is There a Best Way to Set Positive Expiratory-End Pressure for Mechanical Ventilatory Support in Acute Lung Injury?

Airspace collapse is a hallmark of parenchymal lung injury. Strategies to reopen and maintain patency of these regions offer three advantages: improved gas exchange, less lung injury, and improved lung compliance. Elevations in intrathoracic pressure to achieve these goals, however, may overdistend healthier lung regions and compromise cardiac function. Positive expiratory-end pressure is a widely used technique to maintain alveolar patency, but its beneficial effects must be balanced against its harmful effects.