Role of exogenous surfactant in acute lung injury.

OBJECTIVES: To outline both the preclinical and clinical data demonstrating surfactant alterations in acute lung injury, which provide the rationale for testing exogenous surfactant administration in this setting. We also review the results of the randomized, controlled clinical trials conducted to date that have evaluated this therapy in patients with acute respiratory distress syndrome, and we review the various factors that may have affected the outcomes of these trials. Future areas for surfactant research will also be addressed. DATA SYNTHESIS AND EXTRACTION: A review of the literature utilizing a MEDLINE search was performed using the key words: surfactant, surfactant administration, acute respiratory distress syndrome, and lung injury. Personal views are presented and references to unpublished clinical data are made based on the authors' access to this data.
CONCLUSIONS: Exogenous surfactant administration has proven inconsistent as a therapeutic modality for patients with acute respiratory distress syndrome. This is because of the severity of the injury at the time of treatment and because of the variable surfactant preparations, dosing regimes, and delivery methods used in the different trials. Future research efforts will focus on determining the optimal timing of surfactant administration in patients at risk of developing acute respiratory distress syndrome with the aim of preventing progressive lung dysfunction and determining whether surfactant treatments need to be tailored to the specific patient in question. Moreover, with the recognition that surfactant also plays an important role in host defense, the future for surfactant therapy is exciting.