Experimental models of acute respiratory distress syndrome: clinical relevance and response to surfactant therapy.

Surfactant therapy for acute respiratory distress syndrome (ARDS) has shown encouraging results in animal studies, but not always in clinical trials. Efficacy of this therapy may be limited to ARDS caused by indirect injury, but mistiming of its application in clinical trials may be responsible for the discouraging results. In addition, the therapy may not last long enough to be effective. In rats with acidified milk aspiration, the effects of aerosolized surfactant therapy followed by inhalation of aerosolized dextran (molecular weight, 40,000) last significantly longer than those of aerosolized surfactant therapy alone. This mode of surfactant therapy could lead to better results since it can be started and repeated at any time.