Blood Pressure during the Immediate Neonatal Transition: Is the Mean Arterial Blood Pressure Relevant for the Cerebral Regional Oxygenation?

Abstract

Background: Measurement of mean arterial blood pressure (MABP) is feasible during neonatal transition. Objective: The objective of this study was to investigate a potential influence of MABP on the cerebral regional oxygen saturation (crSO₂) in preterm and term infants during the immediate neonatal transition. Materials and Methods: Preterm and term infants were included in this observational study. The crSO₂ was measured by near-infrared spectroscopy with the INVOS 5100C (Somanetics Corp., Troy, MI, USA) during the immediate neonatal transition (15 min after birth). The near-infrared spectroscopy sensor was applied to the left forehead. Furthermore, a pulse oximeter was applied to monitor arterial oxygen saturation (SpO₂) and heart rate (HR). Fifteen minutes after birth, blood pressure was measured noninvasively at the left upper arm. Cerebral fraction tissue oxygen extraction (cFTOE) was calculated from SpO₂ and crSO₂. To investigate a potential association between crSO₂/cFTOE and MABP, we performed a correlation analysis. Results: A total of 462 preterm and term infants (186/292) were included. Mean gestational age was 31.0 ± 3.5 weeks for preterm infants and 38.9 ± 0.8 weeks for full term infants. Mean birth weight was 1.591 ± 630 g in preterm infants and 3.331 ± 461 g in term infants. There was a significant negative correlation between MABP and cFTOE (ρ = -0.19, p = 0.03) in preterm infants but not in term infants (ρ = 0.05, p = 0.39). There was no significant correlation between MABP and crSO₂ in either group. Conclusion: MABP has an impact on cerebral oxygenation in preterm infants. Therefore, blood pressure monitoring during the immediate neonatal transition might be relevant for improving cerebral oxygenation especially in preterm infants.