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 (SpO2), heart rate (HR), cerebral tissue oxygenation (StO2) and amplitude-integrated electroencephalography (aEEG) were simultaneously recorded prior to and up to 4 h after SRT. Results: Mean SpO2, HR and StO2 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 µV 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.

[Clinical value of hypoxanthine concentration assays in diagnosis of hypoxia in newborns]. / Wartosc kliniczna oznaczania stezen hipoksantyny w diagnostyce niedotlenienia u noworodka.

The purpose of this study was to asses the usefulness of hypoxanthine (HYP) concentration as an indicator of hypoxia. Concentration of HYP (HPLC method) in the umbilical arterial cord blood was determined in 145 newborns. Newborns were studied in four groups: premature asphyxiated, term asphyxiated, premature non-asphyxiated, term non-asphyxiated. Newborns were classified as hypoxic if they had: pH < 7.15, BE < -7.0 mmol or PaO2 < 10 mmHg. Reduced umbilical arterial pH, PaO2 and BE correlated directly with increased concentrations of HYP. The highest correlations were observed for HYP and PaO2. The levels of HYP for asphyxiated and non-asphyxiated newborns were different. The results show that HYP concentration is an important indicator in detection of asphyxia in newborns. Strong correlation between parameters of acid base balance and HYP concentration was observed in the studied groups. Increased concentration of HYP confirms intrauterine hypoxia independently of maturity.