inpatient / hematology and oncology

Transfusion Reactions

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If You Remember Nothing Else

Be judicious with who you choose to transfuse. Severe transfusion reactions are rare but life-threatening. Severe reactions can initially present like mild reactions (fevers, local rash/itching); the first time a patient has symptoms the transfusion should be stopped and a workup should be sent to rule out severe reaction before re-transfusion. Patients with mild symptoms can be premedicated with tylenol and benadryl.
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Clinical Pearls

• We do not transfuse whole blood, but rather components of blood including packed red cells, platelets, plasma (clotting factors), and cryoprecipitate (fibrinogen)
• After blood is collected, it is centrifuged in sequence with removal of different components at each step - this leads to packed reds with leftover WBCs that are leukodepleted and/or irradiated, platelets that have some donor antibodies in them, and plasma that has clotting factors and fibrinogen; cyroprecipitate is a smaller volume that just has the fibrinogen and is useful in DIC
• 1 unit of pRBCs raises Hgb by 1; 1 unit platelets raises Plt by ~20-50; plasma response is variable, and 2 units are often given to assess for response in INR; cryoprecipitate is also variable
• Platelets historically have been given as 6 "units" per "dose" when the platelets were taken from whole blood; when taken from pheresis the blood bank creates 1 "dose" that is equivalent to the historical 6 units; make sure you know how much you are ordering
• Massive Transfusion involves giving 1:1:1 RBCs, platelets, and plasma - the goal is to avoid coagulopathy through dilution, but need to also be on the lookout for hypocalcemia (from citrate), hyperkalemia (from lysis), hypothermia (from cooled product)
• Type and Screen - typing is checking for ABO "type"; screening is looking for antigens on the donor RBCs that the host may have abs against; crossmatch is either done electronically if the screen is negative, or manually searching for compatable blood if the screen is positive
• T+S needs to be sent every 3 days because the reactivity of the abs present in the blood sample may not be as robust after sitting for a period of time, and this ensures that something isn't missed; also if patients receive product it is possible during the course of the admission that they will develop antibodies against donor antigens that would only be seen on a repeat sample
• Acute Hemolytic transfusion reaction (AHTR) is caused by ABO incompatability - donor RBCs are destoyed by host abs or donor abs destroy the host RBCs via complement activation which leads to hemolysis and possibly DIC; Febrile nonhemolytic transfusion reaction (FNHTR) is flu-like symptoms caused by cytokines from donor WBCs; Anaphylaxis is a type I reaction to donor plasma proteins (often in IgA deficiency); TRALI is lung injury due to HLA abs that activate WBCs in the host which release cytokines leading to inflammation and edema in the lungs (ARDS); Transfusion Associated Circulatory Overload (TACO) is not a reaction, and is instead simply fluid overload from the volume of product given

Trials and Literature

• Transfusion Reactions - (STATPearls, 2022)

Other Resources