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 less than or equal to 6 breaths/min, assisted ventilation with intermittent mandatory ventilation greater than 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 less than 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.