Surfactant

Pulmonary hemorrhage is a potential complication of surfactant treatment. Although the mechanism for this injury remains incompletely understood, it is postulated that surfactant treatment results in a decrease in pulmonary vascular resistance, an increase in left-to-right shunting across the ductus arteriosus, and the development of hemorrhagic pulmonary edema.

By decreasing the need for prolonged mechanical ventilation and exposure to oxygen, surfactant treatment, administered either at time of delivery (prophylactic therapy) or in static infants within 6 hours of birth (rescue therapy), may reduce lung injury and the occurrence of bronchopulmonary dysplasia (BPD). A meta-analysis of clinical trials has shown a significant reduction in the risk of BPD or death following prophylactic surfactant treatment (relative odds ratio, 0.64; 95% CI, 0.49 to 0.84). Likewise, a significant reduction in the risk of BPD or death has been observed following rescue surfactant treatment (relative odds ratio, 0.66; 95% CI, 0.53 to 0.82).

Surfactant treatment may reduce the occurrence of intraventricular hemorrhage (IVH) by modifying the early course of respiratory distress syndrome and improving cardiopulmonary stability. However, a meta-analysis of clinical trials has shown no positive effect on the incidence of IVH following prophylactic surfactant treatment (relative odds ratio, 0.95; 95% CI, 0.73 to 1.24). A similar lack of effect has been observed following rescue surfactant treatment (relative odds ratio, 0.94; 95% CI, 0.76 to 1.15).

Both prophylactic and rescue administration of surfactant have been shown to decrease the incidence of pneumothorax and other pulmonary air leaks. A meta-analysis has shown a significant reduction in the incidence of pneumothorax following prophylactic (relative odds ratio, 0.31; 95% CI, 0.22 to 0.44) and rescue surfactant treatment (relative odds ratio, 0.34; 95% CI, 0.27 to 0.44).

The improvement in cardiopulmonary stability and oxygenation induced by surfactant therapy may protect preterm infants from nonpulmonary complications, including retinopathy of prematurity (ROP). Although ROP was not tabulated for meta-analysis, no consistent trends on the incidence or severity of ROP have been observed in individual trials.
References:
Dekowski SA, Holtzman RB. Surfactant replacement therapy. An update on applications. Pediatr Clin North Am. 1998;45:549-572
Jobe AH. Surfactant treatment. In: Polin RA, Fox WW, eds. Fetal and Neonatal Physiology. 2nd ed. Philadelphia, Pa: WB Saunders Co; 1998:1321-1335
Mercier CE, Soll RF. Clinical trials of natural surfactant extract in respiratory distress syndrome. Clin Perinatol. 1993;20:711-735