Cerebral hemodynamic change and intraventricular hemorrhage in very low birth weight infants with patent ductus arteriosus.

The aims of this study were to assess the hemodynamics of the cerebral arteries and intraventricular hemorrhage in very-low-birthweight (VLBW) infants with and without patent ductus arteriosus (PDA) by cranial Doppler sonography. VLBW infants with significant PDA were recruited into the study (sPDA) group. Arterial blood gas analysis and complete blood counts were done near the time of the cranial sonography examination. Mechanical ventilator settings and daily fluid intake were recorded. The cranial Doppler sonographic examinations were repeated after PDA closure by indomethacin therapy and/or surgical ligation. A total of 40 preterm infants fulfilled the criteria of the study group. Another 37 preterm infants were recruited into a control group. Mean birth weight and gestational age did not differ significantly between the two groups. Differences in heart rate, blood pH, pCO2, pO2, use of surfactant therapy, mean airway pressure, ventilation index and FiO2 were statistically significant. In the sPDA group before closure of the PDA, the left atrial diameter/aorta diameter ratio demonstrated a positive relationship with resistance index (RI) and an inverse relationship with end diastolic velocities (Vd). After closure of the PDA, these changes neared those of the control group. The overall incidence of intraventricular hemorrhage (IVH) was higher in the sPDA than in the control group. There was no statistical difference in the grading and severity of IVH between the two groups. However, all preterm infants with severe IVH were found in the sPDA group, and their RIs were all higher than 0.80. Cranial Doppler sonography can be a useful tool to evaluate cerebral hemodynamic changes in VLBW infants with sPDA. Increased RI and decreased Vd of the cerebral artery may indicate a probable sPDA, and normalization of the RI and Vd may suggest closure of the sPDA.