Acute Respiratory Distress Syndrome Clinical Network (ARDSNet)

BACKGROUND:

ARDS affects approximately 150,000 people in the United States each year. Despite 20 years of research into the mechanisms that cause this syndrome and numerous developments in the technology of mechanical ventilation, the mortality has remained greater than 50 percent. Many of the patients are young, and to the tragic loss of human life can be added the cost to society because these patients spend an average of 2 weeks in intensive care units and require multiple high tech procedures. Because of the overwhelming nature of the lung injury once it is established, prevention would appear to be the most effective strategy for improving the outlook in this condition.

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 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. The complicated clinical picture makes it difficult to accumulate a large number of comparable patients in any one center. There is no agreement on the optimal supportive care of these critically ill patients. 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.

The concept for the initiative was first discussed at a meeting of the Adult Respiratory Distress Syndrome Foundation and staff of the Division of Lung Diseases. The results of a working meeting on uniform definitions in ARDS held at the 1992 meeting of the American Thoracic Society reinforced the recommendation from the community for National Heart, Lung, and Blood Institute participation in drug evaluation in ARDS. The concept for the initiative was approved by the September 1992 National Heart, Lung, and Blood Advisory Council. The Requests for Proposals were released in October 1993.