66 Investigation of Adverse Effects of Transfusion

Principle

During the transfusion of blood components and products, the patient may experience some adverse effects; often described  “transfusion reactions”. The signs and  symptoms of these reactions are noted by the individual  overseeing the transfusion. Transfusion reactions are classified according to their signs and symptoms, some of which can occur in more than one category. For instance, fever and chills   can be associated with a febrile (mild) or hemolytic transfusion reactions (serious). Life-threatening HTR are almost always due to ABO incompatibility due to an identification error that results in the recipient receiving incompatible red cells. Adverse events are reportable within the quality system and serious events are reportable to Health Canada. Nova Scotia labs participate in a provincial investigation and reporting procedure.

Specimens

Specimens vary and are determined by the patients signs and symptoms. The most common samples include:

• EDTA
• Serum (Red top)
• First Post transfusion Urine sample
• Blood component/ Product returned to lab.

Procedure

1. Clerical checks are performed. The ID of the recipient, pre transfusion specimen, the labeled blood component/blood product and all relevant documents are reviewed for clerical errors.
2. The plasma of the pre vs post transfusion sample are viewed for hemolysis
3. A DAT is performed on the post specimen (EDTA sample). If this DAT is positive a DAT is performed on the pre specimen. An eluate is required if the DAT is positive.
4. ABO grouping is confirmed. If any of the initial tests above give positive or suspicious results then:
5. Repeat the following tests with the pre, post and a new donor segment. (obtained from the returned donor unit)
   1. ABO grouping
   2. Rh grouping
   3. DAT
   4. ABS
   5. Crossmatch
6. Hemoglobin may have to be monitored
7. Serum from both pre and post may be analyzed for haptoglobin assays
8. With suspected transfusion transmitted bacterial sepsis:
   1. The donor product is investigated including a gram stain and cultures of the product contents, not segments.
   2. Recipient should have blood cultures

Interpretation

1. Primary immunization rarely causes significant hemolysis of transfused red cells. Antibodies are detectable no earlier than 7-10 days after transfusion and usually several weeks or months later.
2. A secondary response (anamnestic) may produce high titers of antibody within 3-7 days after transfusion.
3. Elution and identification of the antibody is critical when the DAT becomes positive in a patient who has been transfused within the previous two to three weeks.

Note

1. Signs and symptoms that might accompany HTR:
   1. Fever, chills, chest pain, hypotension, nausea, flushing, dyspnea, hemoglobinuria, shock, generalized bleeding, oliguria or anuria, back pain, pain at infusion site.
2. Certain immunologic and non-immunologic effects give characteristic symptoms:
   1. Immunologic:
      • Hemolysis with symptoms due to red cell incompatibility
      • Febrile nonhemolytic reaction due to donors granulocytes
      • Anaphylaxis due to antibody to IgA
      • Urticaria (hives) due to antibody to plasma proteins
      • TRALI: Noncardiac pulmonary edema due to antibody to wbc’s
   2. Non-immunologic:
      • Marked fever with shock due to bacterial contamination
      • Congestive heart failure due to volume overload (TACO)
      • Hemolysis with symptoms due to physical destruction of blood (ie freezing or overheating) or mixing non-isotonic solutions with red blood cells.
      • Complications of Massive Transfusion: Citrate toxicity, hypothermia, hyper and hypokalemia, coagulopathies.