One-year follow-up of 89 infants with birth weights of 500 to 749 grams and respiratory distress syndrome randomized to two rescue doses of synthetic surfactant or air placebo. Canadian Exosurf Neonatal Study Group. Canadian Exosurf Neonatal Follow-Up Group.

Double-blind neurodevelopmental and physical evaluations were conducted at 1-year adjusted age in 89 infants with birth weights of 500 to 749 gm who had respiratory distress syndrome in the neonatal period and were randomized to receive two rescue doses of a synthetic surfactant (Exosurf Neonatal, Burroughs Wellcome Co., Research Triangle Park, N.C.) or air placebo. The trial used a common protocol and was conducted at 13 hospitals; patients were entered in the trial between February 1988 and September 1990. Ninety-five percent of surviving infants were assessed. Growth and development in the two groups were equivalent. Mean Bayley Scales of Infant Development scores were comparable (mental development index, 79 +/- 22 vs 87 +/- 20; psychomotor development index, 73 +/- 18 vs 81 +/- 19 for air placebo and synthetic surfactant, respectively). The incidence of severe retinopathy of prematurity was significantly decreased in the surfactant group compared with the air placebo group (15% vs 34%; relative risk 0.428; 95% confidence interval 0.2 to 0.9). Overall, administration of surfactant appeared to increase the probability of a favorable outcome. Confirmation of the trends observed in this study would provide a strong rationale for the rescue use of synthetic surfactant in extremely low birth weight infants with respiratory distress syndrome even if overall mortality is not reduced.