256. Blood Transfusions - Compatibility and Complications

Question 1

Three types of RBC compatibility testing

Answer 1

1. TYPE: ABO and RhD typing of patient and donor to determine compatibility
2. SCREEN: patient Ab’s to non-ABO blood group antigens (alloimmunized)
3. CROSSMATCH: patient blood with RBC donor unit for compatibility

Question 2

Allergic Reactions to blood transfusions

• sx
• cause
• tx

Answer 2

Sx: dermal: itching, hives, rash, facial swelling
airway: wheezing, dyspnea

Cause: IgE to allergens in plasma

Tx: anti-histamines (epi, CS if severe)

Usually donor specific, not recurrent

Question 3

Febrile non-hemolytic transfusion reaction

• sx
• cause
• tx

Answer 3

Sx: fever, chills, rigors
Cause: 1. pt Ab’s to donor WBCs in blood; 2. cytokines from donor WBCs generated during storage are released
Tx: anti-pyretics (acetaminophen)

Usually donor specific, not recurrent

Question 4

Transfusion-Assoc Circulatory Overload (TACO)

• sx
• cause
• tx

Answer 4

Sx: dyspnea, hypoxia, pulm edema, cardiac injury
Cause: RBC/plasma in transfusion expands intravascular volume
tx: diuresis

Question 5

Acute Hemolytic Reactions to blood transfusion

• sx
• pathogenesis
• cause
• test
• tx

Answer 5

Sx: fever, chills, HYPOTENSION/shock, dark urine (hemoglobinuria), renal insufficiency, bleeding/prolonged PT/PTT
Pgen: intravascular RBC lysis due to Ab activating inflammation = damage to renal tubules and activate clotting cascade
Cause: incorrect blood specimen (mistransfusion), Ab to RBC unit (may be undetected)

Test: Direct Antiglobulin Test (Coomb’s), repeat compatibility test

Tx: Diuresis to protect kidneys, plasma/platelets if needed for bleeds/coagulopathy, bp support if needed

Question 6

Transfusion-Related Acute Lung Injury (TRALI)

• sx
• cause
• tx
• test
• prevent

Answer 6

sx: dyspnea, hypoxia (diffuse pulm edema) <6hrs after transfusion (maybe fever)
cause: donor plasma Ab’s to patient WBCs = active patient WBCs damage pulm capillaries (donors often multi-P women, pregnancy-induced Ab’s)
tx: resp support
Tests: test donors for anti-HLA, anti-neutrophil Ab’s
Prevent: make plasma from male donors, defer TRALI-causing donors, test parous women platelet donors for HLA Abs

Question 7

Septic Reactions to blood

• sx
• cause
• test
• tx

Answer 7

Sx: fever, chills, rigors, hypotension, shock
Cause: bacteria in blood bag (from donor skin, or donor bacteremia)
Test: culture blood bag
Tx: broad-spectrum ABx
Prevent: donor health screening

Question 8

Anaphylactic Reactions to blood

• sx
• cause
• test
• tx

Answer 8

Sx: severe allergic rxn = hypotension, shock, airway edema and obstruction
Cause: recipient IgE to plasma allergens (sometimes IgA-deficient pts with anti-IgA Ab’s)
Test: IgA level, anti-IgA Ab’s
Tx: antihistamines, Epi, CS
Prevent: wash RBCs/platelets for IgA deficient patients

Question 9

Transfusion Assoc Graft vs. Host Disease

• sx
• cause
• test
• tx
• prevent

Answer 9

Sx: rash, fever, diarrhea, hepatitis, pancytopenia 3-30days post transfusion (LATE)
Cause: lack of normal rejection of transfused WBCs due to severe immunosuppression or closely matched HLA donor (blood relative)
Test: DNA chimerism in blood/tissue (mixed DNA populations)
Tx: immunosuppression of GVHD rxn
Prevent: gamma irradiation of RBCs/platelets for susceptible patients (immunosuppressed, cancer, aplastic anemia, newborns)

Question 10

What are 2 ways of pathogen inactivation in blood transfusions?

Answer 10

1. Solvent-detergent for pooled plasma (disrupts RBCs)
2. Psoralen-UV light: for plasma and platelet units (UV does not penetrate RBCs) - inactivates microbes and donor WBCS (less GVHD)