Cerebral blood flow velocities in newborn infants with perinatal ashpyxia

ABSTRACT

The cerebrovascular hemodynamic alteration in asphyxia and intraventricular hemorrhage in newborn infants were determined by monitoring the pulsatile flow changes in the anterior cerebral arteries using Doppler ultrasound. The pulsatility index measurements, which were calculated from the recorded changes in Doppler frequency shifts, were obtained in four groups of newborn infants, each comprising 20, with the following diagnoses Group I normal term, Group II asphyxia, Group III IVH, Group IV asymptomatic preterm. There was no significant difference between the PI values of groups I and IV. Compared to normal term infants, those diagnosed as having asphyxia had significantly lower PI measurements and those with IVH had significantly higher PI values. The low PI values in asphyxia and prior to the onset of IVH indicate vasodilatation and decreased resistance to blood flow. In IVH, the high PI values denote the opposite. PI =Pulsatility index; S = Mean systolic amplitude; D = mean diastolic amplitude; CBF= Cerebral blood flow; IVH= Intraventricular hemorrhage; AGA= Appropriate for gestational age