High frequency variability of transcephalic electrical impedance — A new parameter for monitoring of neonatal cerebral circulation?

Transcephalic electrical impedance, ECG, respirogram and arterial blood pressure were continuously monitored for 30 minutes at 8-hour intervals during the first day of life in 50 neonates at the neonatal intensive care unit. In 10 infants who developed severe intracerebral haemorrhage high-frequency fluctuatios of impedance signal were significantly lower when compared to controls or infants with mild intraventricular haemorrhage. The fluctuations seemed to be also small in infants with cerebral echodensities and periventricular leucomalacia. This could imply disturbed control of cerebral circulation in these critically ill newborns. We conclude that the variability of the transcephalic electrical impedance is an interesting new parameter for monitoring cerebral circulation which may be helpful already during the first day of life.