Abstract
Animal research has revealed the main pathophysiological mechanisms by which positive pressure ventilation can cause pulmonary barotrauma accompanying the distention of the lungs, and ultimately lead to permeability pulmonary edema. The significance of these mechanisms in the clinical setting has been recognized in recent years, and the publication of studies on acute respiratory distress syndrome (ARDS) patients has focused attention on the importance of using methods of ventilation that do not cause barotrauma. Possible mechanisms behind barotrauma include the overdistention of the lungs by high peak airway pressures or large tidal volumes, shear stress caused by the repeated opening and closing of small airways or alveolar ducts, and the inflammatory process. The importance of preventing overdistention by limiting tidal volume, and preventing small airway closure by the use of positive end-expiratory pressure (PEEP) over the lower inflection point is now known. However, further studies into ventilation methods that minimize barotrauma are needed.
