Transfusion Therapy: Blood Components and Transfusion Complications

Suchitra Pandey

Ashok Nambiar

I. RED BLOOD CELLS (RBCs)

A. General principles.

1. Manufacture and contents.

a. Obtained by apheresis collection or prepared from anticoagulated (citrated) whole blood. Following centrifugation, plasma is removed and additive solution is added.

b. Each unit of packed red blood cells (pRBCs): approximately 200 mL; residual plasma: <50 mL; hematocrit: 55% to 60%.

B. Indications.

1. Augment O₂-carrying capacity in anemic patients.

2. Evidence-based guidelines for hemoglobin (Hgb) thresholds for transfusion.

a. The TRICC (Transfusion Requirements in Critical Care) trial showed that a restrictive red cell transfusion strategy (transfusion trigger of <7 g/dL) was at least as effective as, and possibly superior to, a more liberal strategy (transfusion trigger of <10 g/dL) in critically ill patients, with the possible exception of patients with acute myocardial infarction and unstable angina.

b. The FOCUS (Functional Outcomes in Cardiovascular Patients Undergoing Surgical Hip Fracture Repair) trial showed that even in elderly patients with underlying cardiovascular disease/risk factors, it is reasonable to limit transfusions for symptoms of anemia or a Hgb level of < 8g/dL.

C. Dose, administration.

1. A pRBC unit typically raises Hgb by approximately 1 g/dL in an adult patient.

D. Special requests: see Table 93-1.

II. PLATELETS

A. General principles.

1. Manufacture and contents.

a. Platelet concentrates (PCs).

i. Prepared from whole blood by centrifugation.

TABLE 93-1 Requests for Special Red Cell and Platelet Products

Request/modification	Description	Indications
Irradiation	Gamma-irradiation (25 Gy) inhibits proliferation of lymphocytes—preventing transfusion-associated graft-versus-host disease	Congenital/acquired immunodeficiency Hematologic malignancies Stem cell transplantation HLA-matched products, transfusions from relatives, and granulocyte products Fetus/neonate
CMV negative	Blood donor is negative for CMV antibodies	Immunosuppressed patients and pregnant women who are CMV seronegative Fetus/neonate
Leukocyte reduced^a	Prestorage filtration removes >99.9% of WBCs (residual white cell count <5 × 10⁶ WBCs)	Same as CMV negative Frequently transfused patients (reduces HLA alloimmunization) Recurrent febrile reactions
Washing^b	Removes >98% of plasma proteins and electrolytes	Recurrent or severe allergic/febrile reactions; severe IgA deficiency; risk of hyperkalemia
Volume reduction^c	Centrifugation and removal of >50% of supernatant plasma	Circulatory overload Recurrent allergic reactions
^aLeukoreduced products are considered equivalent to CMV-negative products. Breakthrough infection rates of 1%-2% for CMV-seronegative products and 2% to 3% for leukoreduced products have been reported. ^bWashing RBC units causes a 20% loss of red cells. Washing platelets causes both platelet loss and dysfunction. ^cVolume reduction of platelets results in less platelet loss/dysfunction than washing platelets.

ii. Five to six PCs (each containing approximately 5.5 × 10¹⁰ platelets) are pooled to obtain an adult dose (approximately 300 mL).

b. Apheresis platelets.

i. Collected from single donors; comprise 80% to 90% of platelets transfused in the United States.

ii. Contain approximately 3 × 10¹¹ platelets in 200 to 400 mL plasma; equivalent to a pool of 6 PCs (6-pack).

B. Indications.

1. Active bleeding: patients with low platelet counts or platelet dysfunction.

2. Prophylactically.

a. Platelet counts <10,000 /µL: stable hematological disease.

b. Platelets counts <20,000/µL: fever or mucositis.

c. Platelet counts <50,000/µL: invasive procedures.

d. Platelet counts <100,000/µL: neurosurgery, intracranial bleeding.

3. Platelet transfusions are generally avoided in patients with thrombotic thrombocytopenic purpura, heparin-induced thrombocytopenia, and idiopathic thrombocytopenic purpura.

C. Dose, administration.

1. One apheresis platelet unit typically raises platelet counts by 30,000 to 60,000/µL.

2. Suspect platelet refractoriness if 10- to 60-minute posttransfusion counts show poor increments.

a. Refractoriness due to antibodies against human leukocyte antigen (HLA) and/or platelet-specific antigens requires transfusion of cross-matched or HLA-matched platelets.

b. Nonimmune causes include hypersplenism, fever, and active bleeding.

D. Special requests: see Table 93-1.

III. FRESH FROZEN PLASMA (FFP/FP24)

A. General principles.

1. Manufacture and contents.

a. Obtained by apheresis or separation of plasma from centrifuged whole blood.

b. One unit (approximately 200 mL) contains approximately 1 international unit/mL of each coagulation factor and 400 mg of fibrinogen.

B. Indications.

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