Background: This section is under preparation and will be included in the next issue.
Objectives: To compare the effect of multiple doses of natural surfactant extract to single doses of natural surfactant extract in premature infants with established respiratory distress syndrome.
Search strategy: Searches were made of the Oxford Database of Perinatal Trials, Medline (MeSH terms: pulmonary surfactant; limits: age groups, newborn infant; publication type, clinical trials), previous reviews including cross references, abstracts, conference and symposia proceedings, expert informants, and journal hand searching in the English language.
Selection criteria: Randomized controlled trials comparing a policy of multiple doses of natural surfactant extract to a policy of single doses of natural surfactant extract in premature infants with respiratory distress syndrome were considered for this review.
Data collection and analysis: Data on clinical outcomes including pneumothorax, patent ductus arteriosus, necrotizing enterocolitis, intraventricular hemorrhage (all intraventricular hemorrhage and severe intraventricular hemorrhage), chronic lung disease, retinopathy of prematurity, and mortality were excerpted by the primary reviewer (R. Soll). Data were analyzed according to the standards of the Neonatal Cochrane Review Group.
Main results: Two randomized controlled trials of multiple vs. single dose natural surfactant extract in infants with established respiratory distress syndrome were identified. Meta-analysis of these trials suggests a reduction in the risk of pneumothorax (typical relative risk 0.51, 95% CI 0.30, 0.88; typical risk difference-0.09, 95% CI -0.15, -0. 02) and a trend towards a reduction in mortality (typical relative risk 0.63, 95% CI 0.39, 1.02; typical risk difference -0.07, 95% CI -0.14, 00.00). No complications associated with multiple dose treatment are reported in the identified trials.
Reviewer's conclusions: In infants with established respiratory distress, a policy of multiple doses of natural surfactant extract results in greater improvements regarding oxygenation and ventilatory requirements, a decreased risk of pneumothorax and a trend toward improved survival. The ability to give multiple doses of surfactant to infants with ongoing respiratory insufficiency leads to improved clinical outcome and appears to be the most effective treatment policy.