Transfusion Medicine II

Question 1

Explain the basic rules of blood administration (11)

Answer 1

1. Do not add IV solutions to blood bag or tubing.
2. Blood products should not be exposed to Ca++ containing solutions (e.g., lactated Ringer’s). This will reverse the effect of citrate anticoagulant and cause clotting in the administration set.
3. Do not warm components over 37°C.
4. When blood bag is entered, sterility is breached. Discard after 4 hours at room temperature or 24 hours at 1-4°C.
5. Transfuse PRBCs ≤4 hours.
6. Visually inspect all components before infusion.
7. Identify the unit and recipient.
8. Administer all products through 170-260 mm aggregate filter (standard in the blood administration set).
9. Observe the patient during all transfusions and investigate all adverse events promptly.
10. In vivo crossmatch should be completed when transfusing red cells in the presence of an autoantibody. Infuse 10% of the unit or volume required over 15 min. Monitor vital signs before and after the test infusion. If vital signs change and the patient develops symptoms (anxiety, dyspnea, back pain, etc.), look for signs of hemolysis in a blood sample or urine sample from the patient. If any of the above signs of hemolytic transfusion reaction occur, do not finish transfusing the unit. If transfusion is required, repeat this procedure with the next unit. If there is no reaction to the test dose, complete the infusion.
11. For the neonate, crossmatch can be completed with either baby’s or mother’s serum/plasma.

Question 2

Explain the infectious risks of blood transfusion and describe testing strategies to reduce risks of specific agents.

Answer 2

In addition to screening interview strategies noted previously, screening laboratory tests are completed on all donations and must be negative before the blood products are released for transfusion. This has added dramatically to the safety of homologous transfusions in the past 20 years. The standard tests include testing for antibody against and/or antigen for each infectious agent. In the last 6-8 years, the addition of nucleic acid amplification tests (NAT) for Hepatitis C Virus (HCV), Human Immunodeficiency Virus (HIV), and West Nile Virus (WNV) have been included in the testing scheme, detect viral genome in blood samples from donors, and have decreased the risk of transmission to very low levels. Donors found screen positive and confirmed for an agent are deferred from further donation. The risks of transfusion for transmission of specific agents are as follows: Syphilis <1/300,000. CMV transmission is infrequent with seronegative or leukoreduced products. Screening for Chagas disease is completed depending on region of donation in the U.S.

Question 3

Classify the non-infectious adverse events of transfusion, assess a constellation of symptoms and signs of the prototypic reactions, and describe the clinical management: Febrile non-hemolytic transfusion reactions

Answer 3

(≥ 1°C rise in temperature from pre-transfusion level) and mild allergic reactions (hives, transient skin rashes) are the most common adverse events (1/200 and 1/400, respectively). After confirming that other types of reactions are not occurring in the patient, treatment with antipyretics (e.g., Tylenol) and antihistamines (e.g., Benadryl) are required before re-instating the infusion. Future transfusions may require pre-medication with antipyretics and/or antihistamines or leukoreduced cell containing blood products

Question 4

Classify the non-infectious adverse events of transfusion, assess a constellation of symptoms and signs of the prototypic reactions, and describe the clinical management: Immediate hemolytic transfusion reactions

Answer 4

as a result of infusing incompatible blood products (usually ABO) present an infrequent (

Question 5

Classify the non-infectious adverse events of transfusion, assess a constellation of symptoms and signs of the prototypic reactions, and describe the clinical management: Delayed hemolytic reactions

Answer 5

represent the process of alloantibody production (1/2,500 transfusions) and slow destruction of the sensitizing red cells with very few symptoms and signs. Documentation of these alloantibodies should become part of the medical record since their existence may increase the risk of immediate hemolytic transfusion reactions with future transfusions.

Question 6

Classify the non-infectious adverse events of transfusion, assess a constellation of symptoms and signs of the prototypic reactions, and describe the clinical management: Anaphylactic reactions

Answer 6

are fortunately rare (1/150,000 transfusions) and usually occur without identifying the specific reagent. The bronchospasm and/or large airway response is treated with epinephrine, benadryl and steroids. May be seen in IgA deficient individuals (the most common humoral immunodeficiency syndrome).

Question 7

Classify the non-infectious adverse events of transfusion, assess a constellation of symptoms and signs of the prototypic reactions, and describe the clinical management: Transfusion related lung injury (TRALI)

Answer 7

is acute lung injury (development of diffuse lung infiltrates, problems breathing and difficulty maintaining peripheral oxygen saturation on room air) within 6 hours of a transfusion. Vigorous ventilatory support may be required but the syndrome resolves quickly in 90% of those affected. The risk is 1/5,000-1/3,000 per transfusion depending on the product (all products can cause this reaction).

Question 8

Classify the non-infectious adverse events of transfusion, assess a constellation of symptoms and signs of the prototypic reactions, and describe the clinical management: Transfusion associated circulatory overload (TACO)

Answer 8

is volume (fluid overload) related to excessive amounts of products and/or cardiac dysfunction. Diuretics will help resolve the problem.