Low cerebral activity and cerebral oxygenation during immediate transition in term neonates—A prospective observational study

Abstract

AimTo analyze whether in term neonates during immediate transition after birth low cerebral activity measured by amplitude-integrated EEG (aEEG) is linked to cerebral regional oxygen saturation (crSO2) measured by near-infrared spectroscopy (NIRS). Additionally, the cerebral fractional tissue oxygen extraction (cFTOE) was calculated to analyze whether cerebral activity is linked to cFTOE. MethodsA total of 244 term neonates delivered by primary cesarean section were studied. In addition to routine monitoring with pulse oximetry, aEEG and NIRS measurements were performed during the first 15min after birth. The mean minimum (Vmin) and maximum (Vmax) amplitude of the cerebral activity as well as crSO2 and cFTOE for each minute was determined. Neonates with initial Vmin<5μV or Vmax<10μV, which normalized during transition (study group) were compared to neonates with normal aEEG values throughout the whole monitoring period (control group). Results9 neonates fulfilled inclusion criteria to the study group and were compared to 50 neonates in the control group. Vmin, Vmax, crSO2, SpO2 and cFTOE were compared from the 4th to 15thmin after birth. During our study period, Vmin and Vmax were significantly lower in the study group than in the control group. crSO2 was significantly lower in the study group until minute 11, dropping below the 10th centile in minute 8. cFTOE was significantly higher in the study group until minute 10, rising above the 90th centile in minutes 8 and 9. SpO2 was within normal ranges in both groups. crSO2 and cFTOE were within normal ranges in the control group. ConclusionThe present study demonstrates that neonates with initially low cerebral activity during immediate transition after birth concurrently showed low crSO2 (<10th percentile), but increased cerebral oxygen extraction (cFTOE>90th percentile). Cerebral monitoring with aEEG and NIRS might provide useful information on the neonates’ condition during immediate transition.