Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS): Mediator network

Abstract

During the last decade, many investigations were conducted in order to understand the mechanisms involved in the development of acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). However, the increasing knowledge, instead of clarification, leads us to realize that these terms may assemble a wide variety of lung pathologies. Indeed, many circumstances can result in these syndromes and no particular factor has been defined to distinguish ARDS of one etiology from another. We are still ignorant about which factors lead to the extended inflammation from pneumonia to ARDS, while it is not clear whether the timing of events are determined by some mediators. Furthermore, in the clinical arena, there is no clear distinction between pneumonia, severe pneumonia which may lead to ALI and then ARDS. Finally, the results of all these studies should have allowed us to investigate new therapeutical approaches while none seems to emerge. This review is an analysis by an ICU clinician of the different points of view of these syndromes and intends to give a global vision of the numerous factors implied, emphasizing the complex interactions between them. The present state about new potential treatments directed on mediators is summarized.