Multicenter Trial of Single-Dose Modified Bovine Surfactant Extract (Survanta) for Prevention of Respiratory Distress Syndrome

Abstract

A multicenter, prospective randomized controlled trial was performed comparing the efficacy of a single intratracheal dose of modified bovine surfactant extract (Survanta, 100 mg/kg, Abbott Laboratory, North Chicago, IL) with air placebo in preventing respiratory distress syndrome. Infants were enrolled if they were estimated to be between 24 and 30 weeks' gestation, weighed between 750 and 1250 g, and were intubated and stabilized within 15 minutes after birth. A total of 160 infants were treated (79 with surfactant, 81 with air placebo) between 4 and 37 minutes after birth (median time 12 minutes). Of these, 5 infants were excluded from the final analysis. The 72-hour average values for the arterial-alveolar oxygen ratio, fraction of inspired oxygen, and mean airway pressure were calculated from the area under the curve of scheduled values measured throughout 72 hours. Clinical status was classified using five ordered categories (no supplemental oxygen or assisted ventilation, supplemental oxygen only, continuous positive airway pressure or assisted ventilation with intermittent mandatory ventilation ≤6 breaths/min, assisted ventilation with intermittent mandatory ventilation >6 breaths/min, death). Chest radiographs at 24 hours were graded for severity of respiratory distress syndrome. Infants receiving Survanta had less severe radiographic changes at 24 hours of age and decreased average fraction of inspired oxygen (31% vs 42%, P = .002) compared with control infants. No differences were noted in the average arterial-alveolar oxygen ratio, mean airway pressure, or clinical status on days 7 and 28. A beneficial effect was noted in the incidence of pneumothorax (P = .057) and an increase was noted in the incidence of necrotizing enterocolitis (P = .052). No differences in incidence of patent ductus arteriosus, intraventricular hemorrhage, sepsis, or bronchopulmonary dysplasia were seen. According to results of a secondary analysis, there was improvement in the fraction of inspired oxygen and a greater number of survivors without bronchopulmonary dysplasia in the subgroup of infants weighing <1000 g who were treated with surfactant. It was concluded that a single dose of Survanta given shortly after birth resulted in decreased severity of chest radiographic findings 24 hours after treatment and improved oxygenation during 72 hours after treatment, but did not improve other acute measures of disease severity or clinical status later in the neonatal period. The group at highest risk for respiratory distress syndrome (infants with birth weights between 750 and 999 g) may benefit the most from preventive therapy.