The future of surfactant therapy for patients with acute lung injury - new requirements and new surfactants.

New requirements must be considered when designing trials of new lung surfactants for patients with acute lung injury (ALI). Radiographic inclusion criteria must be carefully applied if they are to generate reproducible patient groups. Strategies for ventilation are now known to significantly affect outcome and also must be clearly defined and applied. Similar mortality rates in patients with different degrees of gas exchange and radiographic abnormalities suggest that prior clinical distinctions should be re-examined. Current trials of surfactant therapy for ALI are examining the efficacy of a natural surfactant, a surfactant containing recombinant SP-C and a surfactant based on an SP-B-like peptide.