Mediators and mechanisms of acute lung injury

In the last decade since this topic was reviewed in this forum, there have been tremendous advances in the understanding of the basic mechanisms of the pathogenesis of acute lung injury (ALI). Translating this knowledge into understanding the development of acute respiratory distress syndrome (ARDS) in humans has been complex. To date, no single mediator or specific group of mediators has been shown to predict the development of ARDS, define ARDS, or be associated specifically and consistently with morbidity from the syndrome. Recently, however, several concepts-including the impact of patient heterogeneity in clinical studies, the potential importance of balance between pro- and anti-inflammatory mediators, and the potential contribution of genetic regulation in the development of ALI-have been introduced that likely will further our understanding of the development of ARDS in patients. One hopes that these concepts can be expanded so that, in the next decade, successful therapeutic interventions for the prevention and treatment of ARDS will become available.