Week 4 Flashcards
Acute Hemolytic Transfusion Reaction
-immunopathology
- hemolysis of donor red cells within 25 hours of transfusion by preformed alloantibodies in the recipient’s circulation.
- commonly due to ABO-incompatible blood being transfused to a recipient with naturally occurring ABO alloantibodies (anti-A, anti-B, anti-A, B). Clerical errors (mislabeling blood or misidentifying patients) account for 80% of such reactions.
describe the immunopathology underlying Febrile Nonhemolytic Transfusion Reactions
- rise in temperature greater than 1°C, which may be accompanied by chills, rigor, or both.
- due to a reaction of HLA or leukocyte-specific antigens on transfused lymphocytes, granulocytes, or platelets in the donor unit with antibodies in previously alloimmunized recipients
describe the immunopathology underlying
Anaphylactic transfusion reactions are sometimes associated with antibodies to immunoglobulin (Ig) A,
describe the immunopathology underlying
results from the transfusion of immunologically competent lymphocytes into an immunologically incompetent host. An individual’s risk depends on whether the recipient is immunocompromised (and to what degree), the degree of HLA similarity between the transfusion donor and recipient, and the number of transfused T lymphocytes capable of multiplying and engrafting
describe the immunopathology underlying
- acute respiratory distress syndrome that occurs within 6 hours after transfusion and is characterized by dyspnea and hypoxia secondary to noncardiogenic pulmonary edema.
- blood donor antibodies with HLA or neutrophil antigenic specificity can be shown to react with the recipient’s leukocytes, leading to increased permeability of the pulmonary microcirculation.
clinical features of Acute Hemolytic Transfusion Reaction
- Fever accompanied by chills
- patient may complain of a general sense of anxiety or uneasiness or pain at the infusion site or in the back or chest
- serious sequela is acute renal failure
- unconscious or anesthetized patient, diffuse bleeding at the surgical site
clinical features of Febrile Nonhemolytic Transfusion Reactions
- fever
- diagnosis made by excluding other causes of fever
clinical features of Allergic /Anaphylactic Reaction
- skin flushing, nausea, abdominal cramps, vomiting, diarrhea, laryngeal edema, hypotension, shock, cardiac arrhythmia, cardiac arrest, and loss of consciousness.
- Fever is notably absent
clinical features of Transfusion-Associated Graft-versus-Host Disease
- Pancytopenia with bleeding and infectious complications
- fatal in approximately 90% of affected patients.
clinical features of Transfusion-Related Acute Lung Injury
- Damage to the pulmonary-capillary endothelium of the recipient
- Dyspnea and hypoxia secondary to noncardiogenic pulmonary edema
- Acute respiratory distress syndrome
delayed hemolytic transfusion reactions
- occurs 3 to 7 days after transfusion of the implicated unit.
- Hemolysis is usually extravascular, and red cells are destroyed in the recipient’s circulation by antibody produced as a result of an immune response to the transfusion.
immediate approach to treatment of a suspected transfusion reaction
Treatment begins with immediate cessation of the transfusion. The risk for renal failure may be reduced by the administration of crystalloid fluids, maintain urine pH at 7.0 and by diuresis with 20% mannitol or furosemide
approach to treatment for, and prevention of, febrile nonhemolytic transfusion reactions and allergic reactions
- can often be prevented by administering antipyretics before the transfusion of blood components. Prestorage leukocyte reduction is recommended to prevent reactions resulting from the accumulation of cytokines during storage.
- Treatment is diphenhydramine
risk factors for TA-GVHD and identify ways to prevent TA-GVHD in susceptible patients
depends on whether the recipient is immunocompromised (and to what degree), the degree of HLA similarity between the transfusion donor and recipient, and the number of transfused T lymphocytes capable of multiplying and engrafting.
