Objective: To study the effects of administration of surfactant immediately after birth (prophylactic) or after 6 hr (therapeutic) to 81 Dutch preterm infants from a multicentre trial.
Setting: University Hospital Leiden and Sint Joseph Hospital, Veldhoven.
Design: A randomized controlled trial with stratification for biochemical lung (im)maturity. The aims of the study were (I): to improve the TcPO2/FiO2 ratio by 40% and (2) to prevent the respiratory distress syndrome by 50% at 6 hours after birth. The secondary goal was to compare effects of prophylactic versus therapeutic use of exogenous surfactant (from 6 hours onwards) in surfactant-deficient infants.
Patients: The entrance criteria of the study were: (I) inborn children with a gestational age between 26 and 30 weeks, (2) elective intubation and (3) sampling of bronchotracheal or gastric aspirate. After randomization the children received surfactant within 10 minutes after birth prophylactically (n = 42) or 6 hours after birth if they needed more than 60% oxygen (13 of 39 control infants). A second dose of surfactant was given if, at 6 hours after the first dose, the FiO2 was still high (> or = 0.6).
Treatment: We used a natural porcine surfactant preparation (Curosurf) in a dose of 200 mg/kg given through the endotracheal tube.
Results: The mean gestational age of the 81 infants was 28.2 weeks. The TcPO2/FiO2 ratios increased in the prophylactic group compared with the controls (38 versus 30 kPa; p < 0.05). RDS occurred less often and less severely in the prophylactic group (p < 0.05). Neonatal mortality was lower in the prophylactically treated infants (3/42) than in the control group (10/39; p < 0.05). Compared with the control infants with immature lungs, the immature prophylactically treated infants had six hours after birth higher TcPO2/FiO2 ratios (35 vs 13 kPa; p < 0.001), a 35% reduction of the incidence of RDS with a significant reduction of its severity (p < 0.05), and significantly lower mean airway pressures (0.87 versus 1.24 kPa; p < 0.005). The surfactant given 6 hours after birth to the immature controls resulted in an immediate improvement of the oxygenation. Nevertheless, these infants spent more time on the respirator and needed extra oxygen for longer periods than the immature infants prophylactically treated (p < 0.05).
Conclusion: Surfactant, given either prophylactically or therapeutically, results in clinical improvement of children with biochemically immature lungs. A prophylactic treatment, moreover, results in reduced incidence and severity of RDS, in a significant shortening of the time spent on the respirator and in reduced need of extra oxygen compared with therapeutic treatment. We recommend to give surfactant prophylactically or at the first signs of RDS.