ABSTRACT
I. Introduction Diffuse alveolar damage (DAD) describes the pathology found in most patients with acute respiratory distress syndrome (ARDS). DAD represents a stereotypical response to one or more insults that injure the alveolocapillary unit (1). The injury may occur predominantly at the alveolar epithelium (as in inhalational exposures) or at the level of the capillary endothelium (such as in sepsis). Regardless of the site of initial injury, the tissue response is the same. Not surprisingly, it is typically difficult to determine the proximal cause based solely on finding DAD.
