Modified bovine surfactant (Survanta) versus a protein-free surfactant (Exosurf) in the treatment of respiratory distress syndrome in preterm infants: a pilot study.

We undertook a prospective, randomized, non-blinded pilot study to determine whether infants with respiratory distress syndrome (RDS) who were treated with protein-containing bovine surfactant (Survanta, Ross/Abbott Laboratories, Columbus, Ohio) had earlier and larger responses in gas exchange when compared with similar infants treated with a synthetic surfactant (Exosurf, Burroughs Wellcome, Research Triangle Park, North Carolina). Forty-one infants weighing between 600 g and 1750 g at birth with RDS of sufficient severity to require assisted ventilation with an FiO2 > 0.39 were enrolled in the study and treated with surfactant from 1 to 8 hours after birth. Infants were randomly selected to receive treatment with either Exosurf or Survanta. Despite randomization, the Survanta group was overrepresented with factors associated with greater severity of RDS (lower birthweight, more males, and fewer African Americans). No statistically significant difference was found in the primary outcome measure (arterial/alveolar PaO2 > 0.3 at 24 hours) by univariate or multivariate analysis. The percentage of responders in the Survanta-treated group was significantly increased 24 hours after treatment in two of four secondary measures of oxygenation when analyzed by univariate tests using one-tailed P values. Based on these results, we anticipate that acute outcomes after Survanta or Exosurf will approximate those found in this trial and that differences in measures of oxygenation between treatment groups will approximate 30% to 50% 24 hours after initial treatment.