Respiratory distress syndrome in preterm infants of less than 32 weeks: What difference does giving 100 or 200 mg/kg of exogenous surfactant make?

Background: Surfactant dosing and effective delivery could affect continuous positive airways pressure (CPAP)-failure. Nevertheless, information on exogenous surfactant dosing with current administration methods is limited. Objective: To describe the effect of 100 or 200 mg/kg of surfactant as first-line treatment of respiratory distress syndrome in preterm infants of less than 32 weeks gestation. Study design: A retrospective single-center cohort study comparing two epochs, before and after switching from 100 to 200 mg/kg surfactant therapy. Results: Six hundred and fifty-eight of the 1615 infants of less than 32 weeks were treated with surfactant: 282 received 100 mg/kg (S-100) and 376 received 200 mg/kg (S-200). There were no differences between S-100 and S-200 in perinatal data including prenatal corticosteroids, medication use, age at first surfactant administration and respiratory severity before surfactant. The S-200 vs. S-100 had fewer retreatments (17.0% vs. 47.2%, p < 0.001) and a shorter duration of oxygen therapy and mechanical ventilation (315 vs. 339 h, p = 0.018; 37 vs. 118 h, p = 0.000, respectively). There was no difference in postnatal corticosteroid use (S-200 10.0% vs. S-100 11.0%, p = 0.361). Bronchopulmonary dysplasia (BPD) was significantly lower in S-200 vs. S-100 when comparing either the 4 and 6-year periods before and after the dose switch (29.4% vs. 15.7%, p = 0.003, and 18.7% vs. 27.3%, p = 0.024, respectively) CONCLUSIONS: The switch from 100 to 200 mg/kg was associated with a marked reduction in the need for surfactant redosing, respiratory support, and BPD. This information could be important when designing a study in the modern era of less invasive administration as surfactant dosing and its effective delivery may affect the outcome.