<qa>  What is the potential for new drug development?Basic research has identified numerous inflammatory pathways that are associated with the development of ARDS. Agents that block these mediators prolong survival in animals with lung injury, and a few of them have been tested in human patients. Because of the large number of putative mediators and the variety of ways that their action can be blocked, the possibility for new drug development is almost infinite. This is an exciting prospect, since it envisions the first effective pharmacologic treatment for ARDS. However, preliminary clinical studies have shown conflicting results, and there is an urgent need for a mechanism to efficiently and effectively test new drugs in ARDS. Treatment studies in patients with ARDS are difficult to perform for three reasons. First, the complicated clinical picture makes it difficult to accumulate a large number of comparable patients in any one center. Secondly, there is no agreement on the optimal supportive care of these critically ill patients. Finally, many of the patients meeting study criteria will not be enrolled in study protocols because of the acute nature of the disease process. For these reasons, therapeutic trials in ARDS require multicenter cooperation. 