Single- versus multiple-dose surfactant replacement therapy in neonates of 30 to 36 weeks' gestation with respiratory distress syndrome

Respiratory distress syndrome (RDS) is the severe impairment of respiration in the premature newborn. This disorder is the leading cause of death among prematurely born infants in the United States. Pulmonary surfactant is a phosphate- and lipid-containing substance that controls the surface tension of air-liquid emulsion present in the lungs. Studies have shown that surfactant helps to prevent or treat respiratory distress syndrome by reducing the oxygen and ventilatory (breathing) requirements of newborns. However, most studies have focused on infants with very low birth weights and have explored the effects of a single or double dose of surfactant. It has been demonstrated that, following a single dose of surfactant, lung function deteriorates after initial improvement. Hence, the effects of multiple doses of surfactant were compared with those of a single dose in treating respiratory distress syndrome in 75 newborns delivered at 30 to 36 weeks' gestation. Oxygenation (oxygen saturation of the blood in the lungs) of the newborns improved within 10 minutes of administering either a single or multiple dose of surfactant. However, oxygenation and ventilation deteriorated within 6 to 12 hours after the first dose of surfactant. This deterioration could be reduced by administering multiple doses of surfactant. Although additional doses of surfactant did not improve ventilatory requirements or the duration of assisted ventilation, additional doses of surfactant were beneficial in sustaining improved oxygenation. These results indicate that surfactant is effective in reducing oxygen and ventilatory requirements in premature infants less than six hours of age with respiratory distress syndrome. The most effective dose and plan for additional treatment requires further investigation. (Consumer Summary produced by Reliance Medical Information, Inc.)