Lec 14

• What is the purpose of blood transfusion?

  Blood transfusion is useful and life-saving when performed with caution and with clear indication.
• What are transfusion reactions?

  Transfusion reactions are unfavorable complications that occur in about 2-4% of blood transfusion cases despite precautions.
• How are transfusion reactions classified?

  They may be broadly divided into Immediate and Delayed reactions.
• What are the complications of blood transfusion?

  1. Immediate reactions:

  • Immunological: Hemolytic transfusion reactions, Febrile nonhemolytic reaction, Allergic reaction, Anaphylactic reaction, Transfusion Associated Lung Injury (TRALI)
  • Nonimmunological: Circulatory overload, Air embolism, Bacterial Contamination of Donor Unit

  1. Delayed reactions:

  • Immunological: Post transfusion purpura, Hemolytic transfusion reactions, Transfusion associated graft versus host disease
  • Nonimmunological: Iron overload (Transfusion hemosiderosis), Thrombophlebitis, Transmission of infectious organisms
• What is the cause of acute hemolytic transfusion reaction?

  Acute hemolytic transfusion reaction is caused by ABO incompatibility between recipient and donor, resulting in destruction of donor cells.
• What are the clinical findings of acute hemolytic transfusion reaction?

  Patients typically develop fever with chills, lumbar pain, dyspnea, tachycardia, and hypotension.
• What can result from intravascular hemolysis in acute hemolytic transfusion reactions?

  Intravascular hemolysis can result in hemoglobinuria, oliguria, and acute renal failure.
• What is a common cause of acute hemolytic transfusion reactions?

  Majority of cases result from clerical errors like wrong labeling of the crossmatch sample.
• How does Rh incompatibility affect acute hemolytic transfusion reactions?

  In Rh incompatibility, hemolysis develops in the extravascular compartment because anti-Rh antibodies are not complement-fixing.
• What is the treatment for acute hemolytic transfusion reaction?

  • Immediate discontinuation of transfusion
  • Maintenance of intravenous access with normal saline
  • Management of hypotension, renal failure, and disseminated intravascular coagulation
• What symptoms characterize febrile nonhemolytic reaction?

  Patients develop fever, chills, rigors, and headache 30 to 60 minutes after transfusion.
• What is the management for febrile nonhemolytic reaction?

  • Stop transfusion
  • Workup for hemolytic transfusion reaction and bacterial contamination
  • Administer oral or rectal antipyretics (paracetamol) and antihistaminics
• What causes allergic reactions during blood transfusion?

  Mild urticaria, rash, and pruritus may develop due to a reaction between plasma proteins and corresponding IgE antibodies in the recipient's plasma.
• What is the recommended action if an allergic reaction occurs during transfusion?

  The rate of transfusion should be slowed and an antihistamine given.
• What characterizes anaphylactic reactions during blood transfusion?

  Anaphylactic reactions are rare and characterized by hypotension, shock, and breathlessness without fever.
• What is the management for anaphylactic reactions during transfusion?

  • Stop transfusion immediately
  • Administer adrenaline and hydrocortisone
• What are the symptoms of Transfusion Associated Lung Injury (TRALI)?

  TRALI manifests within 1 to 4 hours of starting transfusion and is characterized by fever, chills, respiratory distress, and dry cough.
• What causes TRALI?

  TRALI is caused by potent leucoagglutinins in donor blood reacting with recipient's granulocytes, leading to the formation of leucocyte aggregates.
• What is the treatment for TRALI?

  • Treatment is supportive
• What is circulatory overload in the context of blood transfusion?

  Circulatory overload occurs when blood volume and venous pressure increase significantly, potentially leading to acute pulmonary edema.
• Who is at risk for circulatory overload during blood transfusion?

  Individuals such as the elderly, pregnant women, and those with reduced cardiac function are at risk.
• What is the cause of air embolism in blood transfusion?

  Air embolism was common when transfusion was given from glass bottles, but is rare now due to the use of plastic bags with closed tubing systems.
• What can bacterial contamination of donor units cause?

  Bacterial contamination can cause septicemic shock, particularly more common with platelet concentrates.
• Why is bacterial contamination more common with platelet concentrates?

  Bacterial contamination is more common with platelet concentrates because they are stored at higher temperatures (20–24°C) that favor bacterial proliferation.
• How is bacterial contamination diagnosed?

  Diagnosis depends on Gram staining and culture of blood from the blood bag.
• What is a delayed hemolytic transfusion reaction?

  A delayed hemolytic transfusion reaction occurs when the antibody titer is too low to be detected during cross-match, leading to gradual lysis of donor red cells.
• What are the features of delayed hemolytic transfusion reaction?

  • Mild and due to extravascular hemolysis caused by HLA antibodies
  • Develops 4 to 14 days after transfusion
  • Mostly asymptomatic, characterized by unexplained anemia and jaundice
• What is transfusion associated graft versus host disease (TA-GVHD)?

  TA-GVHD is a rare but potentially fatal complication of blood transfusion that may develop 10 to 12 days after transfusion.
• What is the mechanism behind TA-GVHD?

  TA-GVHD occurs when donor blood products contain mature T cells that attack the recipient's tissues, more commonly in immunocompromised recipients.
• What are the clinical features of TA-GVHD?

  • Fever
  • Generalized skin rash
  • Jaundice
  • Diarrhea
  • Features of pancytopenia (due to marrow failure)
• How can TA-GVHD be prevented?

  • By transfusing irradiated blood/components in patients at risk
• What is iron overload (transfusion siderosis)?

  Iron overload occurs in patients receiving multiple transfusions over a few years, leading to excess iron deposition in various organs.
• How can iron overload be prevented or reduced?

  • By giving iron chelating agents (like Desferal)
• What is thrombophlebitis in the context of blood transfusion?

  Thrombophlebitis is inflammation of the vein that may develop in patients with indwelling catheters.
• What infectious complications can arise from blood transfusion?

  Transfusion of infected blood may transmit diseases like AIDS, hepatitis (HBV, HCV, and HDV), HTLV-I and II, malaria, and cytomegalovirus infection.
• How can infectious complications from blood transfusion be prevented?

  • By screening donors for common and ominous infections