Page 370 - Concise Pathology for Exam Preparation ( PDFDrive )

12 Haematology 355

• Acute haemolytic transfusion reactions: Usually due to mismatched transfusion,
these reactions are characterized by hypotension, heat and burning at the site of transfu-
sion, fever, pain in the lower back or chest, bleeding due to DIC, oliguria due to renal
failure. They may be intravascular or extravascular.
• Intravascular haemolytic transfusion reactions are due to an ABO mismatch (type
II hypersensitivity reaction).
• Extravascular haemolytic transfusion reactions are due to presence of an atypical
antibody in the recipient (eg, antiKell) that was undetectable (too low a titre) in the
initial antibody screen.
• Circulatory overload: Rapid transfusion of blood may lead to congestive heart failure.
Particularly prone are patients with severe anaemia and previous history of heart
disease.
• Endotoxic shock and fever due to bacterial contamination of blood.

Delayed Transfusion Reactions
• Delayed haemolytic transfusion: Occur 3–10 days after the infusion of blood and are
most often due to extravascular haemolysis from an atypical antibody reaction against
donor RBCs
• Transfusion hemosiderosis due to chronic or multiple transfusions
• Graft versus host reaction due to granulocyte or WBC transfusion in immune-deficient
patients

mebooksfree.com