General Principles
Blood component therapy involves targeted replacement of specific deficient blood constituents. Component separation minimizes volume overload risk and reduces transfusion reactions compared to whole blood administration. Pediatric and neonatal hematologic pathologies differ vastly from adults, requiring age-specific, evidence-based transfusion strategies.
Packed Red Blood Cells
Packed red blood cells increase oxygen-carrying capacity, improving tissue oxygenation. Component prepared by centrifugation of whole blood within eight hours of collection. Storage maintained at 2-6 degrees celsius. Shelf life extends up to 35-42 days depending on specific additive solutions utilized.
Pediatric and Adolescent indications
Restrictive transfusion guidelines preferred in stable patients, avoiding unnecessary exposure to blood products. Maintenance of hemoglobin >7.0 g/dl acceptable for most perioperative and stable chronic anemia scenarios.
| clinical condition | pre-transfusion threshold |
|---|---|
| stable status with acute blood loss >25% circulating volume | transfuse to restore volume/oxygenation |
| perioperative period | hemoglobin <7.0 g/dl |
| severe cardiopulmonary disease | hemoglobin <12.0 g/dl |
| extracorporeal membrane oxygenation | hemoglobin <12.0 g/dl |
| symptomatic chronic anemia | hemoglobin <7.0 g/dl |
| marrow failure | hemoglobin <7.0 g/dl |
Neonatal indications
Neonatal physiology dictates distinct transfusion thresholds. Physiologic anemia of infancy driven by oxygen-induced downregulation of erythropoietin, shortened red cell lifespan, and rapid body growth. Anemia of prematurity exhibits exaggerated hemoglobin decline due to diminished hepatic erythropoietin synthesis, frequent phlebotomy losses, and rapid red cell mass expansion. Restrictive thresholds yield identical mortality and neurodevelopmental outcomes compared to liberal thresholds.
| postnatal age | ventilated infant threshold | oxygen/cpap infant threshold | no supplemental oxygen threshold |
|---|---|---|---|
| first 24 hours | hemoglobin <12.0 g/dl | hemoglobin <12.0 g/dl | hemoglobin <10.0 g/dl |
| days 2-7 | hemoglobin <12.0 g/dl | hemoglobin <10.0 g/dl | hemoglobin <10.0 g/dl |
| days 8-14 | hemoglobin <10.0 g/dl | hemoglobin <9.5 g/dl | hemoglobin <7.5-8.5 g/dl |
| day 15 onwards | hemoglobin <10.0 g/dl | hemoglobin <8.5 g/dl | hemoglobin <7.5 g/dl |
| term neonate clinical condition | suggested transfusion threshold |
|---|---|
| severe pulmonary disease | hemoglobin <10.0 g/dl |
| moderate pulmonary disease | hemoglobin <8.0 g/dl |
| severe cardiac disease | hemoglobin <10.0 g/dl |
| major surgery | hemoglobin <10.0 g/dl |
| symptomatic anemia (tachycardia, tachypnea, poor weight gain) | hemoglobin <7.0 g/dl |
Hemoglobinopathy specific indications
sickle cell disease
Episodic transfusion indicated for overt stroke, transient pure red cell aplasia, splenic sequestration, acute chest syndrome, multiorgan failure, and preoperative optimization. Chronic transfusion therapy indicated for stroke prevention (abnormal transcranial doppler velocities), silent cerebral infarcts, recurrent acute chest syndrome, and pulmonary hypertension. Transfusion target necessitates maintaining hemoglobin s fraction <30% for stroke prevention. Extended red cell antigen matching (c, e, kell antigens) prevents high rates of alloimmunization.
thalassemia major
Transfusion-dependent beta-thalassemia requires regular transfusions to suppress ineffective erythropoiesis, prevent bony deformities, and permit normal growth. Initiate regular transfusions for persistent hemoglobin <7.0 g/dl on two occasions separated by two weeks. Transfuse patients with hemoglobin >7.0 g/dl if exhibiting growth disturbance, facial bone changes, recurrent fractures, or severe extramedullary hematopoiesis. Pre-transfusion hemoglobin target maintained between 9.5-10.5 g/dl. Post-transfusion target 14-15 g/dl. Transfusion interval typical every 2-5 weeks.
Dosing and administration
Standard volume 10-15 ml/kg. Infusion rate 5 ml/kg/hour. Complete infusion within 4 hours. Double volume exchange transfusion utilizes 5 ml/kg aliquots, maximum exchange rate 2-3 ml/kg/minute.
Platelet transfusions
Platelets mediate primary hemostasis via platelet plug formation. Stored at 20-24 degrees celsius requiring continuous agitation. Shelf life 5-7 days.
Pediatric and adolescent indications
Spontaneous bleeding risk escalates significantly when platelet count falls below 20 x 10^9/l alongside hemorrhagic risk factors. Prophylactic transfusion threshold 10 x 10^9/l for stable patients lacking bleeding risk.
| clinical condition | prophylactic/therapeutic threshold |
|---|---|
| active bleeding | platelet count <50 x 10^9/l |
| major invasive procedure | platelet count <50 x 10^9/l |
| minor invasive procedure | platelet count <25 x 10^9/l |
| marrow failure with hemorrhagic risk factors | platelet count <20 x 10^9/l |
| marrow failure without hemorrhagic risk factors | platelet count <10 x 10^9/l |
| qualitative platelet dysfunction plus bleeding/procedure | transfuse regardless of count, |
Neonatal indications
Fetal and neonatal megakaryocytes exhibit higher proliferative potential but remain smaller with lower ploidy, producing fewer individual platelets per cell. Extremely low birthweight infants commonly experience severe thrombocytopenia in intensive care settings. Prophylactic transfusion at liberal threshold of 50,000/μl paradoxically yields higher rates of major hemorrhage or death compared to restrictive threshold of 25,000/μl.
| Neonatal clinical condition | suggested transfusion threshold |
|---|---|
| stable neonate, no bleeding | platelet count <25,000/mm3 |
| active bleeding | platelet count <50,000/mm3 |
| current coagulopathy | platelet count <50,000/mm3 |
| preoperative status | platelet count <50,000/mm3 |
| neonatal alloimmune thrombocytopenia (previously affected sibling with hemorrhage) | platelet count <50,000/mm3 |
| major bleeding (significant intraventricular hemorrhage) | platelet count <1,00,000/mm3 |
| major surgery | platelet count <1,00,000/mm3 |
specific thrombocytopenic conditions
Neonatal alloimmune thrombocytopenia arises from maternal alloantibodies targeting fetal human platelet antigens (commonly human platelet antigen-1a). Intracranial hemorrhage risk approaches 10-20%, frequently occurring prenatally. Transfuse antigen-negative or washed maternal platelets for severe bleeding or extreme thrombocytopenia. Maternal immune thrombocytopenia involves passive placental transfer of maternal autoantibodies. Hemorrhage risk significantly lower than alloimmune variety. Immune thrombocytopenic purpura in older children managed primarily via observation, intravenous immunoglobulin, or corticosteroids. Platelet transfusion strictly contraindicated in immune thrombocytopenic purpura unless life-threatening hemorrhage present due to rapid destruction of transfused donor platelets.
Dosing and administration
Standard volume 10-20 ml/kg. Transfusion elevates platelet count by 50,000-100,000/μl.
Fresh Frozen Plasma
Component contains functional coagulation factors ii, v, x, xi, fibrinogen, antithrombin, protein c, protein s, and albumin. Extracted from whole blood and frozen within 8 hours of collection.
Indications
| condition | rationale for plasma administration |
|---|---|
| severe clotting factor deficiency plus bleeding | replaces missing procoagulant proteins |
| severe clotting factor deficiency plus invasive procedure | prophylactic correction to prevent surgical bleeding |
| emergency reversal of warfarin | rapidly replenishes vitamin k-dependent factors |
| dilutional coagulopathy (massive transfusion) | prevents massive hemorrhage complications |
| natural anticoagulant protein deficiency | replaces antithrombin, protein c, or protein s |
| thrombotic thrombocytopenic purpura | plasma exchange replacement fluid |
| disseminated intravascular coagulation | replaces consumed factors in bleeding neonate |
| vitamin k deficiency bleeding | treats hemorrhagic disease of newborn |
Contraindications
Not indicated for asymptomatic prolonged prothrombin or activated partial thromboplastin times. Avoid utilization for volume expansion or hypovolemia treatment. Inappropriate for hemophilia a, hemophilia b, or von willebrand disease management due to availability of safer, highly purified specific factor concentrates.
Dosing and administration
Volume requirement 15-20 ml/kg. Infusion rate 10-20 ml/kg/hour.
Cryoprecipitate
Prepared by controlled thawing of fresh frozen plasma at 4 degrees celsius, followed by refreezing the insoluble precipitate. Constitutes highly concentrated source of fibrinogen, von willebrand factor, factor viii, factor xiii, and fibronectin.
Indications
| condition | rationale for cryoprecipitate administration |
|---|---|
| severe hypofibrinogenemia (<1.0 g/l) | rapid concentrated fibrinogen replacement |
| congenital factor viii deficiency | utilized only if specific factor concentrate unavailable |
| congenital factor xiii deficiency | utilized only if specific factor concentrate unavailable |
| von willebrand disease | utilized if bleeding active and desmopressin ineffective/contraindicated, |
| afibrinogenemia/dysfibrinogenemia | treats active bleeding or provides preoperative prophylaxis |
Dosing and administration
Volume requirement 1-2 units per 10 kg body weight or 1-2 units per 5-10 kg. Administration elevates recipient fibrinogen by 60-100 mg/dl.
Granulocyte transfusions
Provides functional neutrophils for severe, unresponsive bacterial or fungal infections in profoundly neutropenic patients. Component collected via leukapheresis from donors stimulated with recombinant granulocyte colony-stimulating factor and dexamethasone.
Indications
| patient population | clinical criteria for transfusion |
|---|---|
| children and adolescents | severe neutropenia (<0.5 x 10^9/l) plus progressive infection unresponsive to antimicrobial therapy |
| children and adolescents | qualitative neutrophil defect plus progressive infection unresponsive to antimicrobial therapy |
| neonates (infrequently utilized) | neutrophil count <3.0 x 10^9/l (first week) or <1.0 x 10^9/l (thereafter) plus fulminant bacterial infection |
Dosing and administration
Neonates and infants <10 kg require 1-2 x 10^9 neutrophils/kg per dose. Older infants and small children require minimal 1 x 10^10 neutrophils per dose. Adolescents require 5-8 x 10^10 neutrophils per dose. Administer daily until infection resolution or endogenous neutrophil recovery >1.5 x 10^9/l. Abo/rh crossmatch compatibility absolutely required due to significant concurrent red blood cell content in apheresis product.
Massive transfusion protocols
Defined as replacement of >40 ml/kg total blood products within 24 hours in pediatric patients. Goal entails 1:1:1 ratio administration of plasma, platelets, and packed red cells. Prevents dilutional coagulopathy, treats trauma-induced coagulopathy, and corrects concurrent acidosis and hypothermia associated with massive hemorrhage.
Blood component modifications
Pre-storage and pre-transfusion alterations mitigate specific adverse reactions and enhance component safety profile.
Leukoreduction
Universal filtration removes >99.9% (3-log reduction) of donor leukocytes.
- Prevents febrile non-hemolytic transfusion reactions.
- Diminishes human leukocyte antigen alloimmunization risk.
- Mitigates transfusion-transmitted cytomegalovirus infection risk (considered equivalent to cytomegalovirus-seronegative units).
Irradiation
Gamma or x-ray exposure (25-50 gray) irreversibly inactivates donor t-lymphocytes. Eliminates risk of fatal transfusion-associated graft-versus-host disease.
- Indicated for preterm neonates <1200 g.
- Indicated for known or suspected cellular immunodeficiency syndromes.
- Indicated for all intrauterine transfusions.
- Indicated for directed blood donations from biological relatives.
- Indicated for human leukocyte antigen-matched platelet transfusions.
Washing
Procedure removes plasma proteins, anticoagulants, and extracellular additive solutions. Re-suspends cellular component in sterile saline.
- Indicated for immunoglobulin a deficiency to prevent anaphylaxis.
- Indicated for recurrent severe allergic transfusion reactions.
- Indicated for large volume/exchange transfusions to prevent severe hyperkalemia and arrhythmias.
- Indicated to remove maternal autoantibodies from maternal platelet donations utilized for neonatal alloimmune thrombocytopenia.