Transfusion reaction

1. TRANSFUSION REACTION

2. • In blood transfusion practice, most important blood group
systems are ABO and Rh.
• This is because, A, B, and Rh D antigens are the most
immunogenic (i.e. capable of eliciting a strong antibody
response on stimulation) and
• their alloantibodies can cause destruction of transfused red
cells or induce hemolytic disease of newborn (HDN).
• ABO antigens are also important in organ transplantation.

3. • In ABO system, there are four main types of blood groups:
• A, B, AB, and O. Identification of these four blood groups is
based on presence or absence of A and/or B antigens on red
cells.
• According to Landsteiner’s law, anti-A and/ or anti-B antibodies
are always present in plasma of individuals who lack
corresponding antigen(s) on their red cells
• ABO is the only blood group system, in which if an antigen is
absent in an individual, corresponding antibody is always
present in plasma.

7. TRANSFUSION REACTION

8. Main causes of transfusion-related
deaths are:
• Immediate acute hemolytic transfusion reaction (ABO
incompatibility)
• Pulmonary edema and congestive heart failure (circulatory
overload)
• Bacterial contamination of blood unit
• Transfusion of physically damaged red cells (e.g. by heat, cold)
• Transfusion-associated graft vs. host disease

10. ACUTE HEMOLYTIC TRANSFUSION REACTION
• Intravascular destruction of donor red cells by antibodies in the recipient.
• It results from transfusion of ABO mismatched blood to the recipient due most commonly to
a clerical error.
• Most severe reaction occurs if group A blood is transfused to a group O recipient.
• Pathophysiology consists of antigen-antibody reaction that leads to complement activation
and intravascular hemolysis.
• This causes hypotension, shock, acute renal failure, and disseminated intravascular
coagulation.
• Signs and symptoms (that appear within minutes of starting transfusion) include fever, pain
at the infusion site, loin pain, tachycardia, hemoglobinuria, and hypotension. In
anesthetized patients, bleeding and hypotension are the only indications.

12. Laboratory features are:
• Hemoglobinemia (pink coloration of plasma after centrifugation
of post-transfusion sample)
• Positive direct antiglobulin test
• Hemoglobinuria
• Schistocytes (fragmented red cells) and spherocytes on blood
smear
• Elevated indirect serum bilirubin

13. FEBRILE NON-HEMOLYTIC TRANSFUSION REACTION
• This is the most common transfusion reaction.
• It occurs in about 1% of all transfusions and is defined as “ an
unexplained rise of temperature of atleast 1°C during or shortly after
transfusion “.
• It is caused by the release of pyrogenic cytokines from white cells (during
storage of blood unit or following transfusion due to reaction of
alloantibodies with white cells of donor).
• This reaction is common in multiply-transfused patients.
• Signs and symptoms include fever, chills, and tachycardia.
• Diagnosis depends on exclusion of other causes of febrile transfusion
reaction.

15. BACTERIAL CONTAMINATION OF DONOR UNIT
• Transfusion of an infected blood product is more common with platelet concentrates since
platelets are stored at a higher temperature (20-24°C) that promotes multiplication of
contaminating bacteria.
• Organisms depend on the nature of blood product.
• Platelets are usually contaminated with gram-positive cocci,
• while red cells are contaminated with Yersinia enterocolitica, Escherichia coli, or
Pseudomonas species.
• Signs and symptoms include high grade fever with rigors, hypotension, and shock.
• Laboratory studies include inspection of blood bag for discoloration, and Gram staining and
culture of blood from the blood bag and from the recipient.
• Direct antiglobuin test is negative.

16. TRANSFUSION-ASSOCIATED LUNG INJURY
• This is an acute respiratory disorder that manifests with fever, chills,
dyspnea, and dry cough. X-ray shows diffuse pulmonary infiltrates.
• One probable mechanism is reaction of anti-HLA or anti-neutrophil
antibodies in donor blood with leukocytes of the recipient leading to the
formation of leukocyte aggregates;
• these aggregates deposit in pulmonary vasculature and cause increased
vascular permeability and pulmonary edema.

17. DELAYED HEMOLYTIC TRANSFUSION REACTION
• This is a hemolytic transfusion reaction occurring several days or weeks after transfusion.
• This occurs in individuals who have been sensitized to a red cell antigen by a previous
transfusion or pregnancy so that the antibody is present in a low titer.
• On re-exposure, there is a secondary IgG immune response and mainly exravascular
hemolysis.
• This reaction is typically associated with Kidd antibodies.
• Signs and symptoms include fever, mild jaundice, and mild anemia. Laboratory features
include raised indirect serum bilirubin, spherocytes on blood smear, anemia, and positive
direct antiglobulin test.

19. ANAPHYLACTIC REACTION
• This rare reaction occurs in IgA-deficient recipients in whom anti-IgA
antibodies react with IgA in donor plasma, leading to activation of
complement and
• formation of anaphylatoxins (C3a and C5a).
• Signs and symptoms include development of acute hypotension, shock,
and dyspnoea after transfusion of a few drops of blood.

20. • ALLERGIC REACTION
• This results from type I hypersensitivity reaction to some donor plasma proteins.
• It is the second most frequently reported transfusion reaction.
• Signs and symptoms include mild urticaria, rash, and pruritus.
• VOLUME OVERLOAD
• This occurs if transfusion rate is too rapid, or excessive, or if cardiac or renal impairment is present.
• It causes cardiac failure and lung edema.
• IRON OVERLOAD
• Each unit of blood contains 200 mg of iron.
• Patients receiving regular transfusion therapy such as those with thalassemia develop manifestations of
parenchymal damage due to iron accumulation.

21. COMPLICATIONS ASSOCIATED WITH MASSIVE TRANSFUSION
• Massive transfusion refers to transfusion of stored blood equivalent to patient’s blood
volume in 24 hours.
• Morbidity and mortality is due to rapid blood loss coupled with transfusion of stored blood.
• Storage of blood is associated with loss of 2,3- diphosphoglycerate, lowering of pH, loss
of ATP, loss of platelet function, and depletion of coagulation factors.
• Microaggregates composed of leukocytes and platelets form gradually in stored blood

22. Rapid transfusion of large volumes of stored blood leads to:
• Dilution of platelets and coagulation factors
• Hyperkalemia (due to release of potassium from stored red cells)
• Hypocalcemia (due to binding of calcium by citrate)
• Hypothermia (due to rapid infusion of large amount of cold blood)
• Adult respiratory distress syndrome due to migration of microaggregates to lungs.

23. RECOGNITION AND INVESTIGATION OF A TRANSFUSION REACTION
• All reactions following blood transfusion should be considered as hemolytic in nature and should be
investigated accordingly

25. 1. Transfusion should be immediately stopped, leaving open intravenous line with normal saline.
2. All paperwork and blood bag should be checked for clerical error.
• More than 90% of hemolytic transfusions result from a clerical error (i.e. a wrong unit of blood is
given to the wrong recipient).
3. Blood bank is informed immediately and the blood bag, administration set, and post-transfusion
blood and urine samples should be sent to the blood bank.
4. Evidence of hemolysis: Obtain a post-transfusion blood sample from the recipient, centrifuge,
and observe for pink discoloration of overlying plasma (hemoglobinemia); this is the most rapid way
of detecting intravascular hemolysis if pre-transfusion sample is normal. Similarly, visual examination
of patient’s urine can be done for hemoglobinuria.
• Blood smear examination will show fragmented red cells and spherocytes. Indirect serum bilirubin
is raised.

26. 5. Evidence of blood group incompatibility: Perform a direct antiglobulin test (DAT) on post-
and pretransfusion blood samples. Positive DAT on posttransfusion sample (with negative test
on pretransfusion sample) is indicative of an immunological hemolytic transfusion reaction.
Blood group incompatibility will also be revealed on
(i) repeat ABO grouping on recipient’s pre- and post-transfusion samples and on donor unit,
and
(ii) repeat crossmatching of donor blood against recipient’s pre- and post-transfusion samples.
6. Investigations for detection of complications of hemolytic transfusion reaction:
• Tests for disseminated intravascular coagulation: Blood smear, coagulation screen, and test
for fibrin degradation products
• Tests for acute renal failure: Blood urea, serum creatinine, and serum electrolytes
7. Bacteriological culture if the cause of the acute transfusion is still not clear.

27. Autologous Transfusion
• In autologous transfusion, patient’s blood is collected and is re-infused back subsequently
when required
There are three methods of autologous transfusion:
• Predeposit (preoperative blood donation)
• Acute normovolaemic haemodilution
• Blood salvage.

29. PREDEPOSIT AUTOLOGOUS BLOOD TRANSFUSION
• This technique is applicable to those patients who are posted for elective
surgery
• Patient’s blood is collected in a blood bag before elective surgery, stored in
the blood bank, and is re-infused back after surgery to replace the
operative blood losses.
• Blood collection from the patient starts 5 weeks before surgery. One unit of
blood is collected every 7 days. Patient should be living near the
transfusion centre.
• Maximum of total 4 units can be collected, with the number depending on
the nature of surgery. The last donation is collected at least 4 days before
operation to allow restoration of plasma volume.
• Before each donation, haemoglobin level should be >11.0 g/dl.

30. ACUTE NORMOVOLAEMIC HAEMODILUTION
• Immediately before beginning surgery, patient’s whole blood (1 or 2 units) is
collected in blood bag(s) containing suitable anticoagulant.
• To maintain the blood volume, equivalent amount of crystalloid (at least 3 ml
for every 1 ml of blood collected) or colloid (1 ml for every 1 ml collected)
solution is infused.
• During surgery, the artificially created acute normovolaemic haemodilution
will reduce the red cell loss for the given amount of bleeding.
• The collected blood units are returned back to the patient after surgical
bleeding is controlled. Blood collected from the patient is labelled and kept
near the patient. It remains at room temperature for only a short period so
that there is minimal loss of coagulation factors and platelets.
• Testing and cross matching are not carried out.

31. BLOOD SALVAGE
• Blood salvage consists of collection of blood that is shed during surgery (intraoperative blood
salvage) or following surgery (postoperative blood salvage) and subsequent re-infusion of the
recovered blood to the same patient.
• Blood salvage can be carried out in elective as well as emergency surgery when expected
blood loss is extensive, e.g. cardiac surgery, total knee replacement, trauma surgery, ruptured
ectopic pregnancy, or ruptured spleen.
• This procedure should not be carried out if salvaged blood is contaminated with bowel
contents, urine, bacteria, amniotic fluid, or malignant cells.
• Re-infusion of blood that was collected more than 6 hours back can be harmful due to red cell
lysis, hyperkalaemia, and bacterial contamination.
• The technique requires an expensive automated blood salvage device and for each patient
costly disposable materials.
• In postoperative blood salvage, blood is recovered from wound drains and re-infused back
directly through a filter.