AIM: The aim of the study was to determine whether regional cerebral tissue oxygen saturation (rc SO2 ) and fractional tissue oxygen extraction (FTOE), using near-infrared spectroscopy, are associated with neurodevelopmental outcome of preterm infants.
METHOD: We measured rc SO2 on days 1, 2, 3, 4, 5, 8, and 15 after birth in 83 preterm infants (<32wks gestational age), and calculated FTOE=(SpO2 -rc SO2 )/SpO2 . Cognitive, motor, neurological, and behavioural outcomes were determined at 2 to 3 years using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III), an age-specific neurological examination, and the Child Behavior Checklist (CBCL) respectively. Multiple linear regression analyses were used to determine whether rc SO2 and FTOE contributed to outcome.
RESULTS: We followed up 67 infants. The lower quartile (P25-50 ) and highest quartile (P75-100 ) of rc SO2 on day 1 were associated with poorer cognitive outcome (p=0.044 and p=0.008 respectively). A lower area under the curve (AUC; over 15d) of rc SO2 was associated with poorer cognitive outcome (p=0.014). The lower quartile (P25-50 ) AUC of rc SO2 was associated with poorer fine motor outcome (p=0.004). The amount of time rc SO2 <50% on day 1 was negatively associated with gross motor outcome (p=0.002). The highest quartile of FTOE on day 1 was associated with poorer total motor outcome (p=0.041).
INTERPRETATION: Cerebral oxygen saturation during the first 2 weeks after birth is associated with neurodevelopmental outcome of preterm infants at 2 to 3 years. High and low rc SO2 on day 1 were associated with poorer neurodevelopmental outcome.