THE EFFECT OF BLOOD TRANSFUSION ON CEREBRAL BLOOD‐FLOW IN PRETERM INFANTS: A DOPPLER STUDY

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Abstract
Stable infants with anaemia needing a transfusion with adult red blood-cells were studied to elucidate changes in brain blood-flow velocity. Within 24 hours and at five to six days following transfusion a substantial mean flow velocity reduction was observed. Haemodynamic factors contributing to the reduction were an increase in cerebrovascular resistance and an increase in whole blood viscosity, as reflected by a raised pulsatility index. Transfusion with adult red blood-cells causes an elevation in haemaglobin concentration, thereby increasing the total oxygen-carrying capacity of arterial blood; however, this lowers the concentration of fetal haemoglobin which possesses a higher affinity for oxygen. Since cerebral oxygen transport is equal to the product of cerebral blood-flow and arterial oxygen content, this finding suggests the existence of a homeoglobin rose above 30 percent. At higher fetal haemoglobin levels, appropriate elevations in cerebral blood-flow occurred, causing an increase in the supply of oxygen to the brain.