Surfactant replacement therapy for respiratory distress

Surfactant replacement was established as an effective and safe therapy for immaturity-related surfactant deficiency by the early 1990s. The available evidence indicates that surfactant replacement increases survival rates without an increase in risk of disabilities. However, the risk of long-term disability remains uncertain, because few follow-up studies at school age and adolescence for preterm infants treated with surfactant have been reported. Moreover, the impact of antenatal steroids and continuous positive airway pressure (CPAP) on outcomes in preterm infants is still under debate.
The Committee on Fetus and Newborn recently published a clinical report reviewing available evidence and new findings about surfactant replacement therapy, antenatal steroids use and CPAP in newborn infants.
Surfactant replacement therapy. Overall, results of clinical and experimental studies indicate that surfactant replacement, given either as prophylaxis or as rescue treatment, reduces the incidence and severity of respiratory distress syndrome, air leaks, and mortality in preterm infants. In particular, prophylactic surfactant administration to infants of less than 30 weeks' gestation with a low rate of exposure to antenatal steroids reduces mortality, and the frequency and severity of adverse outcomes compared with infants who receive placebo or rescue surfactant. On the other hand, early rescue surfactant (<2 hours from birth) given to infants of less than 30 weeks' gestation with a low rate of exposure to antenatal steroids reduces the frequency of adverse respiratory outcomes compared with later rescue surfactant. Surfactant replacement has also been shown to improve oxygenation, without an increase in morbidity, in neonates with meconium aspiration syndrome and sepsis or pneumonia. Surfactant treatment may also reduce morbidity and mortality for infants with pulmonary hemorrhage and it does not seem to affect the incidence of neurologic, developmental, behavioral, medical, or educational outcomes.
Antenatal steroids. Preterm infants at risk of surfactant deficiency benefit from antenatal steroid exposure. In fact, antenatal steroids decrease mortality, the severity of respiratory distress syndrome, surfactant use, and intraventricular hemorrhage in infants born at less than 34 weeks' gestation and decrease the incidence of respiratory distress syndrome in infants born at between 28 and 34 weeks' gestation. Furthermore, it has been shown that antenatal steroids and postnatal surfactant replacement independently and additively reduce mortality, severity of respiratory distress syndrome and air leaks in preterm infants.
CPAP. Large, randomized clinical trials are needed to evaluate if CPAP, with or without exogenous surfactant, may reduce the need for mechanical ventilation and the incidence of bronchopulmonary dysplasia without increased morbidity.
Summary. Taken together, these findings suggest that surfactant should be given to infants with respiratory distress syndrome as soon as possible after intubation irrespective of exposure to antenatal steroids or gestational age. Prophylactic surfactant replacement should be considered for extremely preterm infants at high risk of respiratory distress syndrome, especially infants who have not been exposed to antenatal steroids, while rescue surfactant may be considered for infants with hypoxic respiratory failure attributable to secondary surfactant deficiency, (eg, meconium aspiration syndrome, sepsis/pneumonia, and pulmonary hemorrhage). Further randomized trials are needed to fully evaluate surfactant-dosing strategies for infants born to mothers who are receiving antenatal steroids, as well as the efficacy of CPAP, with or without surfactant, during a brief intubation, compared with prophylactic or early surfactant replacement in preterm infants.

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