Chapter 3 - Transfusion Thresholds in the Neonatal Intensive Care Unit: What Have Recent Randomized Controlled Trials Taught Us?

Abstract

Anemia occurs when the red blood cell (RBC) mass does not adequately meet the oxygen demands of tissues. Neonates often require RBC transfusions because of significant anemia resulting from acute blood loss or chronic anemia from physiologic anemia and blood loss from phlebotomy. In particular, anemia in preterm infants (the anemia of prematurity) is more severe, presents earlier in life, and extends beyond the typical nadir seen in term infants. RBC transfusions are currently the accepted treatment for an acute need to increase oxygen delivery to tissues. The indications for neonatal RBC transfusions differ based on the rate of fall in hemoglobin (i.e., acute vs. chronic loss of RBCs). Although target hemoglobin and hematocrit (values below which a transfusion is administered) have been used as clinical indicators for RBC transfusion, it remains uncertain what target hematocrit or hemoglobin will optimally balance the risks and benefits of transfusions in preterm and term neonates. Based on the available data, it appears that a restrictive approach results in fewer transfusions and does not increase the risk of death or serious morbidity. Studies evaluating liberal versus restrictive approach for neonatal transfusions are near completion and should provide evidence on which to base future transfusion guidelines in neonates.