Blood Transfusion in The Neonate Presented by R1 簡維宏

Pathophysiology of Neonatal Anemia (I) Physiologic factor 1.Nadir, weeks Healthy term infants: 9g/dL Infants weighing kg: 8g/dL Infants weighing < 1.0kg: 7g/dL

Pathophysiology of Neonatal Anemia (II) 2.Diminished EPO output in response to anemia Inadequate production of EPO Premature infants rely on the liver rather than kidney Decreased EPO production under conditions of tissue hypoxemia in utero may offer an advantage to the fetus Increased clearance or volume of distribution of this hormone in neonates relative to adults

Pathophysiology of Neonatal Anemia (III) Phlebotomy blood losses 1.Sampling has range from ml/kg/d 2.Total RBCs lost during hospitalization 30%-300% of the total circulating RBC volume

RBC Transfusions to Treat Neonatal Anemia (I) Maintain Hct > 40% for severe cardiopulmonary disease Maintain Hct > 30% for moderate cardiopulmonary disease and for major surgery

RBC Transfusions to Treat Neonatal Anemia (II) Maintain Hct > 25% for symptomatic anemia –Unexplained breathing disorder –Unexplained abnormal vital sign –Unexplained poor growth –Unexplained diminished activity

Patterns of Neonatal RBCs Transfusions at The University of Iowa See Table 1 Prevention and treatment of respiratory diseases among VLBW infants –Surfactant therapy –Antenatal steroid therapy –Improved ventilatory management

Red Blood Cell Product for Transfusion (I) Fresh RBCs v.s Stored RBCs (i) –The rise in plasma K+ levels After 42 days storage, plasma K+: 0.05meq/ml Given a 15ml/kg transfusion of pRBCs will received 3ml extracellular fluid, or 0.15 meq K+ Not apply to large-volume transfusion or infused rapidly

Red Blood Cell Product for Transfusion (II) Fresh RBCs v.s Stored RBCs (ii) –Drop in RBC 2,3DPG –See table 2

Red Blood Cell Product for Transfusion (III) Leukocyte reduction to prevent CMV  -irradiation to prevent GVHD –High risk group Severe cellular immune defect Receiving intrauterine transfusions with or without subsequent exchange transfusions Received blood component from blood relatives

Recombinant EPO to Treat Neonatal Anemia The role of EPO therapy to treat this condition is undefined It seems reasonable to treat stable infants weighing kg with EPO

Despite success in minimizing respiratory disease and in utilizing EPO optimally, many premature infants will require RBC transfusions When these transfusions are unavoidable, effort should be made to limit donor exposure –Supplying all RBC needs from a singe unit of blood –Collecting and storing placental blood (autologous transfusion)