Cerebral hemodynamics during early neonatal period in preterm infants with periventricular leukomalacia

We prospectively investigated the relation among cerebral blood flow, periventricular leukomalacia (PVL) and hypocarbia using Doppler ultrasonography in 53 preterm infants with gestational age between 27 and 34 weeks who required mechanical ventilation during the first 72 h of life. Cerebral blood flow of pericallosal artery was assessed by Doppler ultrasonography at the first and the third day of life. Mean velocity (MV) and Resistance index (RI) of anterior cerebral artery were calculated from the data obtained by Doppler ultrasonography. The diagnosis of PVL was made in 12 infants on the basis of the results of ultrasonography and MRI. Hypocarbia was judged as positive when both arterial blood gas analyses before and after the ultrasonography revealed PaCO2 values <25 mmHg. On the first day of life, RI was 0.62±0.022 in infants with PVL and 0.71±0.014 in those without PVL. On the third day of life, RI was 0.60±0.032 in infants with PVL and 0.66±0.013 in those without PVL. There was a significant difference in RI between the two groups at either point. MV was not significantly different between the two groups at either point. There was no significant difference in RI or MV between infants with and without hypocarbia at either point. RI was significantly lower in infants with PVL during the first 72 h of life, which is suggestive of vasoparalysis in such infants at the level of major cerebral arteries. However, RI or MV was no different between infants with and without hypocarbia.