No differences in the risk of patent ductus arteriosus, intraventricular hemorrhage, severe intraventricular hemorrhage, bronchopulmonary dysplasia, bacterial sepsis are reported in the individual studies or supported by the meta-analysis. The meta-analysis demonstrates a trend towards a decreased risk of mortality. Although the initial trials of single dose surfactant therapy demonstrated dramatic results regarding early improvement in oxygenation and ventilatory support, clinical outcome was not as promising as anticipated. The use of repeated dosing was an attractive way to improve and sustain response to surfactant therapy. Two randomized controlled trials reported on the effect of a policy of multiple dose surfactant therapy compared to a policy of single dose therapy with natural surfactant extract.
Sustained response is reported in the group that received multiple doses of surfactant.
The meta-analysis suggests a decreased risk of pneumothorax and a trend toward a decreased risk of mortality. A more sustained response is seen in infants with respiratory distress syndrome who are allowed multiple doses of natural surfactant extract. Meta-analysis suggests improvement in clinical outcomes including decreasing the risk of pneumothorax. The ability to give multiple doses of natural surfactant extract appears to be the most desirable approach to treatment. Specific criteria for repeat doses and timing of repeat doses could be refined in future studies.