11.3 Blood Product Therapy, Leukapheresis, and Coagulation Therapy

This section is CPHON Domain III.A.4, III.A.7, and III.B.4: which product, for which child, and why it is modified. Technique—consent, dual identifiers, 15-minute vital signs, tubing, and rate—lives in the later supportive-care blood-product administration chapter. Do not turn this page into a skills checklist. Turn it into product choice.

Modified cellular products for immunocompromised children

Children receiving intensive chemotherapy, HSCT, or with severe T-cell immunodeficiency need irradiated cellular products. Irradiation prevents transfusion-associated graft-versus-host disease (TA-GVHD), in which donor lymphocytes engraft and attack the recipient. TA-GVHD is usually fatal. Directing a unit of unirradiated packed red cells to a child on day +4 after allogeneic transplant is a never-event. Directed donations from blood relatives are particularly risky without irradiation because of shared HLA haplotypes.

Leukoreduction removes white cells, cutting febrile non-hemolytic reactions and lowering CMV transmission and HLA alloimmunization. CMV-safe products (leukoreduced and/or CMV-seronegative per blood-bank policy) are used for CMV-seronegative immunocompromised children, including HSCT recipients and some infants. Follow the blood bank's operational definition; the CPHON concept is CMV-safe for the immunocompromised, not a homemade serology algorithm.

A 2-year-old with AML on induction who needs red cells gets irradiated, leukoreduced (and CMV-safe per policy) product. "Any O-negative unit from the trauma fridge" is not a pediatric oncology plan.

Platelets, red cells, and refractoriness—thresholds are protocol-specific

Platelets are given for active bleeding or to cover a procedure (lumbar puncture, central-line placement, surgery) at a count the protocol or surgeon names. Red cells are given for symptomatic anemia—tachycardia, hypoxia, high-output strain, severe pallor with distress—not because a number is aesthetically low. Do not invent a universal 7 g/dL red-cell trigger as ONCC fact. Cooperative groups and transplant programs publish their own numbers; your job is the indication (bleeding, procedure, symptoms) and the modified product, not a single national gram-per-deciliter law.

Platelet refractoriness means the count does not rise as expected after transfusion. Immune causes involve HLA or platelet-specific antibodies. Next products are HLA-matched or crossmatched platelets, plus investigation of fever, splenomegaly, and consumption. Keep giving random pools forever while the child oozes is not a strategy.

A 6-year-old with ALL and platelets of 8,000/µL who needs an intrathecal dose gets platelets timed to the lumbar puncture per protocol. A well-appearing outpatient with a hemoglobin of 8.4 g/dL and no symptoms is not automatically transfused because a website said "seven."

Reactions: stop the transfusion

When a reaction is suspected, stop the transfusion, keep the line open with saline, check the identity of child and unit, notify the provider and blood bank, and treat by syndrome. Do not finish the bag "because there are only 40 mL left."

TRALI (transfusion-related acute lung injury) versus TACO (transfusion-associated circulatory overload) is the discrimination item: TRALI is permeability edema, often hypotensive or febrile; TACO is hydrostatic overload, often hypertensive. Both start with stop.

A 5-year-old who wheezes and drops blood pressure three minutes into platelets has anaphylaxis until proven otherwise: stop, epinephrine per emergency protocol, and do not restart the same unit. A 16-year-old on chronic transfusion who becomes hypoxic and hypertensive with rales near the end of a second red-cell unit is TACO until you prove TRALI; sit the child up and give the ordered diuretic after the bag is stopped.

Leukapheresis, exchange transfusion, and coagulation products

Leukapheresis mechanically removes circulating blasts in hyperleukocytosis when the team chooses it, and it is also how CAR-T T cells are collected. Hyperleukocytosis emergency management—hydration, avoidance of empiric red-cell transfusion that raises viscosity, uric-acid control—lives in the later emergency hyperleukocytosis chapter. Here, know that leukapheresis is a treatment modality with two pediatric jobs: selected hyperleukocytosis and cellular-therapy collection. A 15-year-old with AML, a white-cell count in the hundreds of thousands, and respiratory distress is an emergency-chapter patient who may also be on an apheresis machine; an 8-year-old in remission walking to leukapheresis for CAR-T collection is a planned collection.

Exchange transfusion in sickle cell disease replaces sickle red cells with hemoglobin-A cells and lowers the HbS fraction without overshooting viscosity the way a simple large-volume transfusion can. Classic indications include overt ischemic stroke and severe acute chest syndrome. Chronic exchange or simple-transfusion programs prevent recurrent stroke after abnormal transcranial Doppler—see the sickle-cell section. Technique of the exchange belongs with administration; the CPHON product choice here is exchange rather than simple transfusion when viscosity and HbS fraction are the problem.

Coagulation therapy matches the missing protein or the clot-stability problem:

• Factor replacement (VIII for hemophilia A, IX for B) for bleeds and procedures.
• Vitamin K for deficiency or warfarin-type coagulopathy (dietary, malabsorption, some antibiotics).
• Cryoprecipitate when fibrinogen is the hole (DIC, massive bleed, congenital hypofibrinogenemia).
• Fresh frozen plasma (FFP) for multiple-factor replacement or coagulopathy when a specific concentrate is not the right product.
• Antifibrinolytics—aminocaproic acid or tranexamic acid—for mucosal bleeding (mouth, nose, menses) as adjuncts, not as substitutes for factor in a head bleed.
• Emicizumab is a factor VIII mimetic for hemophilia A prophylaxis. Combining it with activated prothrombin complex concentrate (aPCC) raises thrombosis and thrombotic microangiopathy risk—caution, call the hemophilia center, do not stack those products as a default (see the coagulopathy section).

A 10-year-old with hemophilia A and persistent epistaxis may receive factor plus an antifibrinolytic. A 4-year-old on emicizumab whose knee is swollen still needs a breakthrough factor plan, not an aPCC-plus-emicizumab stack. A toddler with DIC and an unmeasurable fibrinogen needs cryoprecipitate in the conversation, not FFP alone as a fibrinogen strategy.

The CPHON product on this page is the right modified unit, the right reason to transfuse, a stopped bag when a reaction starts, leukapheresis and exchange named for their indications, and coagulation products matched to fibrinogen, vitamin K, mucosa, or factor—not a universal hemoglobin of 7.