Although there are many theories regarding the pathogenesis of the respiratory distress syndrome (RDS), as well as many therapeutic approaches, the etiology remains obscure. Since the hyaline membranes found in this condition are composed of fibrin, the relationship of fibrinolytic enzymes to the development and/or progression of the disease in premature infants has been under investigation.
In a recent issue of the American Journal of Diseases of Children,1 serial euglobulin fibrinolysis determinations in premature infants with and without RDS have been reported and provide a better understanding of the relationship of the fibrinolytic enzyme system with age, maturity, and the respiratory distress syndrome. A study of 82 premature infants (750 to 1,750 gm) and 19 full-term infants revealed a changing pattern of fibrinolytic activity with age. Premature infants had less fibrinolytic activity than full-term infants during the first 55 hours of life. Premature infants with RDS had still less