Changes in hemodynamics, cerebral oxygenation and cerebrovascular reactivity during the early transitional circulation in preterm infants.

BACKGROUND: Changes in systemic and cerebral hemodynamics in preterm infants during early transitional circulation are complex and may differ between infants with or without intraventricular hemorrhage (IVH). METHOD: In total, 43 infants born at median (range) 25 + 5 (23 + 3-31) had continuous near-infrared spectroscopy (NIRS) monitoring of tissue oxygenation index (TOI) and cerebrovascular reactivity within the first 48 h of life. Measurements of left and right cardiac outputs (LVO, RVO) and patent ductus arteriosus (PDA) were collected at 6, 12, 24, and 48 h of life. RESULTS: LVO increased within the first 48 h in the IVH (P = 0.007) and no-IVH (P < 0.001) groups. The pattern of change in LVO and RVO was not different between these two groups. TOI was lower in the IVH (P < 0.001) group. A positive correlation between TOI and LVO (P = 0.003) and a negative correlation between the tissue oxygen reactivity index (TOx) and LVO (P = 0.04) were observed at 24 h of life in the IVH group. PDA diameter was not different between IVH groups at any time interval. CONCLUSION: Cerebral oxygenation was lower and cerebrovascular reactivity was passive to systemic blood flow at 24 h in infants who developed an IVH.