Crossmatching & Transfusion Reactions

Cards (41)

  • Patient identification is the most crucial step in compatibility testing and a common type of error
  • Serum is the preferred specimen for compatibility testing.
    • Hemolysis should be avoided
  • Plasma is not used in compatibility testing because it may cause small fibrin clots to form which may be difficult to distinguish from true agglutination.
    • It may also inactivate complement so that antibodies may not be detected.
  • The freshest sample possible should be used for compatibility testing.
    • Specimens must be less than 3 days old if the patient has been transfused or pregnant within the past 3 months.
  • Sample storage in compatibility testing
    • The AABB requires that patient samples must be stored between 1-6 °C for at least 7 days after transfusion
  • ABO grouping is the most critical pretransfusion serologic test in compatibility testing
  • If the patient’s ABO group cannot be satisfactorily determined and immediate transfusion is essential, group O packed red cells should be utilized.
  • If Rh type of the recipient cannot be determined and transfusion is essential, Rh-negative blood should be given
  • Crossmatching
    • Major X-match = Donor’s cells + Recipient’s serum
    • Minor X-match = Donor’s serum + Recipient’s cells
  • The purpose of crossmatching is to final check the ABO compatibility between patient and donor to prevent transfusion reaction.
    • It detects the presence of antibody in patient’s serum that will react to donor’s RBC that is not detected in antibody screen.
  • 3 phases of crossmatching
    • Immediate Spin in saline at room temp
    • detects IgM
    • Thermophase or 37°C incubation for 30 minutes with enhancement medium such as albumin, LISS, PEG
    • detects IgG
    • AHG Phase after washing incubated cells with saline
  • In phases of crossmatching, Check cells or Coombs control cells (IgG sensitized cells) should be added to tubes that demonstrate no agglutination
  • For results to be considered valid in crossmatching, agglutination must occur.
  • A compatible crossmatch is indicated by absence of agglutination and/or hemolysis at any stage of the crossmatch.
    • The absence of agglutination indicates that the patient has no demonstrable antibodies with specificity for any antigen on donor’s RBC.
  • A) ABO/Rh typing
    B) + DAT
    C) Low incidence Ab
  • A) Alloantibody
  • A) Autoantibody
    B) Roleaux
  • Blood substitutes are substances that is able to carry oxygen in the absence of intact red cells
  • Stroma-free Hemoglobin solutions or Hemoglobin-based Oxygen Carriers
  • Perfluorochemicals are excellent gas (O2 and CO2) solvents
  • Transfusion therapy or lesion of storage
  • Autologous transfusion is a donation of blood by patients for transfusion to themselves in the future
  • Emergency transfusion is given to patients who are bleeding rapidly and uncontrollable.
    • Group O negative units should be used especially if the patient is a woman of childbearing years
  • Massive transfusion is defined as the replacement of one or more blood volume/s within 24 hours or about 10 units of blood in an adult
  • Premature infants frequently require transfusion of small amounts of blood to replace blood drawn for laboratory tests, called Neonatal transfusion
    • Blood units less than 5 days old are preferred to lessen the risk of hyperkalemia and to maximize the 2,3 DPG levels
  • Acute/Immediate hemolytic transfusion reaction is the most severe and may be life threatening due to ABO incompatibilities
    • S/S: fever, chills, hemoglobinuria, dyspnea, hypotension
    • Most severe cases may results to DIC and Renal Failure
  • Acute/Immediate hemolytic transfusion reaction
    • The associated hemolysis is intravascular
    • Mediators: IgM Abs (usually to ABO antigens), complement
  • Febrile nonhemolytic transfusion reaction increases temperature of greater than 1°C after transfusion; mild immunologic reactions that are caused by the interaction of recipient antibodies against HLS Antigens on Donor’s WBC and platelets
    • Most common S/S: fever and chills
    • Management/prevention: use of leukocyte filters during transfusion; Antipyretic
  • Allergic transfusion reaction is the second most common type of transfusion reactions
    • IgE mediated
    • S/S: Urticaria, Erytheme, Hives, Itching, Anaphylaxix
    • Management/Prevention: Administration of Antihistamines before the transfusion
  • Anaphylactic transfusion reaction
    • Mediator: plasma proteins, antibodies to IgA
    • M/P: transfusion of IgA-deficient compounds
  • In Noncardiogenic pulmonary edema, most consistent finding is Anti-leukocyte Abs in donor or patient plasma
  • Good example of iatrogenic transfusion reaction is transfusion associated circulatory overload
    • Common in patients with cardiac and pulmonary disease
    • May lead to congestive heart failure and pulmonary edema
  • Delayed hemolytic transfusion reaction is characterized by the accelerated destruction of transfused RBCs
    • most commonly associated with a secondary response
  • Delayed hemolytic transfusion
    • The associated hemolysis is generally Extravascular
    • Mediators: IgG Abs to Rh, MNS, Kell, Kidd and Duffy antigens
  • Transfusion associated Graft vs. Host disease occurs when immunologically competent lymphocytes are transfused into an immunocompromised host.
    • S/S: Fever, liver problems, rash and diarrhea
    • M/P: transfusion of irradiated blood components
  • Graft vs. host disease occurs when white blood cell in transfused blood attack the tissues of a transfusion recipient who has a severely weakened immune
  • To prevent WBC from causing GVHD, donated blood can be treated with radiation before transfusion
  • Post-transfusion purpura is a rare transfusion reaction usually seen in older female patients who have been sensitized to platelet antigens, either by previous pregnancy or transfusion.
    • Characterized by severe thrombocytopenia one week after transfusion due to antibody to platelet specific antigen
  • Transfusion-induced Hemosiderosis is the iron deposition in vital organs seen in patients who are thalassemics and with chronic transfusions
  • Transfusion of stored blood has not been shown to transmit syphilis because spirochetes do not survive at ref temp for 72 hours