Changes in cerebral tissue oxygenation and fractional oxygen extraction with gestational age and postnatal maturation in preterm infants.

ABSTRACT

OBJECTIVE: This study examined the correlation of cerebral tissue oxygen saturation (SctO2) and cerebral tissue fractional oxygen extraction (cFTOE) with gestational age (GA) and postnatal age over the first 28 days of life. STUDY DESIGN: Preterm infants with birth weight (BW) <1500 g were monitored with near-infrared spectroscopy (NIRS) during the first 28 days of life. SctO2 and cFTOE measurements were analyzed using a linear mixed model. RESULTS: A total of 70 preterm infants were included. Mean SctO2 decreased with increasing GA; SctO2 was 76.4% and 74.6% in the first 24 h for infants 24 and 28-week GA, respectively. For infants born at 24 and 28 it decreased to 52.9% and 58.4% at 28 days of life, respectively. cFTOE increased with increasing GA and postnatal age. CONCLUSIONS: There is an inverse relationship between SctO2 and gestational age and postnatal age but a direct relationship between cFTOE with GA and postnatal age.