SIP

Subject: Blood Banking

Topic: Tranfusion Reaction Investigations

Transfusion reaction is any adverse outcome associated with the infusion of blood or blood components. The most common signs & symptoms are chills, fever & urticaria. Patients can show these symptoms during or within several hours after transfusion.

Require:

• 5 ml clotted blood (purple capped tube)
• 5 ml plain blood (yellow capped tube)
• Pre-tranfusion specimen (taken for crossmatching before transfusion reaction)
• Donor pilot tube & segment tube* from blood pack

*pilot tube - blood segment taken from blood pack before transfusion
*segment tube - taken from blood pack after transfusion

1. Exclude clerical errors
The transfused blood pack and patient sample are examined for the following to exclude possible clerical errors in patient or blood identification in the lab:

• Patient identification (name & IC no.)
• Unit ID on both blood bag & label
• Pre-reaction records on patient's buff card (ABO/Rh typing, antibody screening & compatibility results)
• Computer record of both patient & blood unit

2. Visual check
Visual check is done on both the Post I (blood sample) & Post II (blood & urine samples) for hemolysis. (E.g. Haemoglobinaemia, haemoglobulinuria & spherocytosis)

3. Exclude serological errors
a) ABO blood grouping and Rh typing are performed on the following for evidence of a mismatched ABO/Rh or gross incompatibility:

Patient's
- Pre transfusion sample
- Post transfusion sample I (Post I)
- Post transfusion sample II (Post II)

Donor's
- Pilot tube
- Blood pack/segment

b) Direct Antiglobulin Test (DAT) is performed on patient's sample (pre, post I & post II) & donor's sample (pilot tube & segment).
- To demostrate antibodies/complement bound to red cells in vivo.

c) Compatibility testing between patient's samples (Pre, Post I & II serum) & donor's cells are repeated.

d) Antibody screening on the patient's samples (Pre, Post I & II serum) for clinically significant Ab are repeated.

4. Biochemical analysis
Plain blood (yellow cap) sample is sent for biochemical investigations of:

• Serum bilirubin
  (High level of bilirubin -> haemolysis)
• Haptoglobulin
  (Low level of haptoglobin –> increased intravascular haemolysis)

5. Immunohaematological investigation (HLA Ab test)
The test is done when the patient has any 1 of the symptoms (chills, rigors, elevated temperature)and suspected of non-haemolytic febrile transfusion reaction.

6. Bacteriological investigation
The blood pack is sent for sterility testing.
- Perform gram stain & culture the donor's unit to check for bacterial contamination.

Classification

Type of Reaction	Positive Results
Acute Haemolytic Reaction	- Visual changes suggestive of hemolysis - Mismatched ABO/Rh typing - Missed antibody - Missed inappropriate crossmatching - Biochemical hemolysis
Reaction due to Bacterial Contamination	- Visual changes suggestive of bacterial contamination - Positive culture result
Non-Haemolytic Febrile Transfusion Reaction	- Presence of HLA antibodies
Allergic Transfusion Reactions	- Presence of IgA antibody

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