Role of prophylactic surfactant in preterm infants

Abstract

INTRODUCTIONRespiratory distress syndrome (RDS) in preterm neonates is caused by a deficiency or dysfunction of pulmonary surfactant. Surfactant lines the alveolar surface and prevents atelectasis at end expiration. Pulmonary surfactant is predominantly dipalmitoylphosphatidylcholine with lesser amounts of other phospholipids including phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylinositol. Pulmonary surfactant also contains neutral lipids and distinct surfactant proteins. The physiologic function of surfactant includes the ability to lower surface tension, as well as the ability to rapidly adsorb and spread, associated with the respiratory cycle. The first attempts to utilise synthetic surfactants occurred in the 1960s. The first successful animal model of surfactant replacement therapy was conducted by Enhorning and coworkers in 1972. Enhorning administered a crude natural surfactant extract obtained from lavage of the lungs of mature rabbits 1 directly into the trachea of immature rabbits. Improvement in lung compliance and alveolar expansion was noted. Success in animal models led to widespread clinical trials of surfactant therapy in the human newborns. A systematic review of the seven randomised controlled trials that compare the prophylactic administration of synthetic surfactant to control treatment in preterm infants at risk of developing RDS suggests that prophylactic administration of synthetic surfactant leads to a significant decrease in the risk of pneumothorax, pulmonary interstitial emphysema, and neonatal mortality.2-4 So far, no trials of prophylactic surfactant in preterm neonates were carried out in our country because of the prohibitive cost of the imported drug. During the last decade, preparations of exogenous surfactant have been marketed in our country. This has made it possible to evaluate the prophylactic role of surfactant in preventing respiratory distress syndrome and its associated morbidities in preterm neonates. The present study was designed to find out whether prophylactic administration of surfactant leads to a significant decrease in the risk of neonatal mortality and neonatal morbidity. MATERIALS AND METHODSThis was an experimental study in which a total of 125 preterm newborns less than 34 weeks gestation were studied. The study was carried out in two phases from December 2003 to November 2006. The inclusion criteria were designed to include newborn babies who were less than 34 weeks gestational age at the time of birth. The gestational age assessment was Role of prophylactic surfactant in preterm infants