Surfactant protein A concentrations in tracheal aspirate fluid from infants requiring extracorporeal membrane...

To understand the lung abnormalities leading to respiratory failure in infants, we measured 35,000-dalton surfactant protein A concentrations in tracheal aspirate fluid collected daily from 25 infants receiving extracorporeal membrane oxygenation (ECMO). Surfactant protein A concentrations were standardized per milligrams of total protein present in the aspirate. Among the 23 survivors with complete data, the surfactant protein A concentration increased significantly with time (p less than 0.0001). Concurrent increases in lung compliance (p less than 0.0001) and radiographic scores (p less than 0.0001) were also observed. This increase in surfactant protein A content may reflect lung recovery from barotrauma and oxygen toxic effects or be a response to the primary pulmonary disease process. The two infants who did not survive extracorporeal membrane oxygenation failed to demonstrate these trends.