Despite many advances in the management of lung disorders of premature infants, respiratory distress syndrome (RDS) remains the major cause of morbidity and mortality in the preterm infant. Approximately 30% of infants born at less than 34 weeks gestation will develop RDS, secondary to deficiency in surfactant production by alveolar type II pneumocytes. Without surfactant, work of breathing is increased and gas exchange impaired by diffuse atelectasis, reduced pulmonary compliance and ventilation perfusion mismatch.