Initial clinical trial of EXOSURF, a protein-free synthetic surfactant, for the prophylaxis and early treatment of hyaline membrane disease.
EXOSURF is a protein-free surfactant composed of 85% dipalmitoylphosphatidylcholine, 9% hexadecanol, and 6% tyloxapol by weight. A single dose of 5 mL of EXOSURF per kilogram body weight, which gave 67 mg of dipalmitoylphosphatidylcholine per kilogram body weight, or 5 mL/kg air was given intratracheally in each of two controlled trials: at birth to neonates 700 through 1350 g (the prophylactic trial, n = 74) or at 4 to 24 hours after birth to neonates greater than 650 g who had hyaline membrane disease severe enough to require mechanical ventilation (the rescue trial, n = 104). In both studies, time-averaged inspired oxygen concentrations and mean airway pressures during the 72 hours after entry decreased significantly (P less than .05) in the treated neonates when compared with control neonates. Thirty-six percent of the treated neonates in the rescue study had an incomplete response to treatment or relapsed within 24 hours, suggesting the need for retreatment in some neonates. In the rescue trial, risk-adjusted survival increased significantly in the treated group. There were no significant differences in intracranial hemorrhages, chronic lung disease, or symptomatic patent ductus arteriosus between control and treated infants in either trial.
Intratracheal administration of synthetic surfactant to infants with established respiratory distress syndrome has been demonstrated to improve clinical outcome. Infants who are treated with synthetic surfactant have a decreased risk of pneumothorax, a decreased risk of pulmonary interstitial emphysema, a decreased risk of intraventricular hemorrhage, a decreased risk of bronchopulmonary dysplasia, a decreased risk of neonatal mortality, a decreased risk of mortality prior to hospital discharge and at 1 year of age. Infants who receive synthetic surfactant treatment for established RDS have an increased risk of apnea of prematurity.