Reference values of regional cerebral oxygen saturation during the first 3 days of life in preterm neonates

Background:Currently, reliable reference values of regional cerebral oxygen saturation (rScO₂) for different gestational age (GA) groups are lacking, which hampers the implementation of near-infrared spectroscopy (NIRS) alongside monitoring arterial oxygen saturation (SaO 2) and blood pressure in neonatal intensive care. The aim of this study was to provide reference values for rScO₂ and cerebral fractional tissue oxygen extraction (cFTOE; (SaO₂-rScO₂)/SaO₂) for small adult and neonatal NIRS sensors.Methods:In this study, 999 infants born preterm (GA <32 wk) were monitored with NIRS during the first 72 h of life. Mixed modeling was used to generate reference curves grouped per 2 wk of GA. In addition, the influence of a hemodynamically significant patent ductus arteriosus, gender, and birth weight were explored.Results:Average rScO₂ was ∼65% at admission, increased with GA (1% per week) and followed a parabolic curve in relation to postnatal age with a peak at ∼36 h. The cFTOE showed similar but inverse effects. On average, the neonatal sensor measured 10% higher than the adult sensor.Conclusion:rScO₂ and cFTOE reference curves are provided for the first 72 h of life in preterm infants, which might support the broader implementation of NIRS in neonatal intensive care.