Cerebral oxygenation and bioelectrical activity in preterm infants during surfactant replacement therapy with porcine and bovine preparations

Introduction: Surfactant replacement therapy (SRT) might cause acute changes in cerebral oxygenation and alteration of brain bioelectrical activity. Varying physiologic responses and clinical outcomes were observed when different surfactant preparations were instilled to treat neonatal respiratory distress syndrome (RDS). Material and methods: Neonates born at 26-30 weeks of gestation with RDS requiring intubation and mechanical ventilation were randomized to SRT either with poractant alfa (A) or beractant (B). Saturation (SpO(2)), heart rate (HR), cerebral tissue oxygenation (StO(2)) and amplitude-integrated electroencephalography (aEEG) were simultaneously recorded prior to and up to 4 h after SRT. Results: Mean SpO(2), HR and StO(2) values were comparable between groups at baseline and after SRT. There were differences in mean aEEG voltage before SRT, but amplitudes were within a range considered as normal in both groups. Immediately after SRT and at a few single post-intervention time points mean aEEG voltage was higher in the beractant group. There was a significant difference in the percentage of time with the aEEG signal < 5 mu V after SRT between groups (mean 25.7% (A) vs. 16.5% (B), p < 0.05). Quantity of bursts per minute and mean length of inter-burst intervals (IBI) in the aEEG recording varied insignificantly but there was a significant difference in the percentage of IBI > 30 s between groups (52.5% (A) vs. 36.6% (B), p <0.05). Conclusions: This is the first study assessing brain bioelectrical function and oxygenation while using two different surfactant preparations in a neonate. Cerebral effects of SRT are observed regardless of the type of surfactant, but their magnitude may depend on the preparation and/or dosing used.