Case study: An old woman is admitted to the hospital for a routine surgery. Her medical history reveals that she has blood group, B-negative. The hospital's blood bank has only A-positive and O-positive blood units available. She requires a blood transfusion during surgery. (a) S

Question

Case study: An old woman is admitted to the hospital for a routine surgery. Her medical history reveals that she has blood group, B-negative. The hospital's blood bank has only A-positive and O-positive blood units available. She requires a blood transfusion during surgery. (a) State the potential risks of transfusing A-positive blood into the old woman.

**OR**

Case study: A patient is complaining of frequent urination, excessive thirst, hunger and tiredness. On examination his fasting blood sugar level is found higher than 130 mg/dL on two occasions. He also experiences fatigue and abdominal pain. (a) State the main cause of the patient's worsening symptoms.

Accepted Answer

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> [!TLDR]
> Giving A-positive blood to a B-negative patient risks a dangerous immune (agglutination/haemolytic) reaction, both from the ABO mismatch and from Rh sensitisation.
>
> Blood group compatibility depends on matching both the **ABO** and the **Rh** blood group systems. This patient's blood group is **B-negative** — meaning her red blood cells carry the B antigen (and no A antigen), and her plasma naturally contains **anti-A antibodies** (since the immune system produces antibodies against whichever ABO antigens are absent from its own red cells); she also lacks the Rh (D) antigen, being **Rh-negative**.
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> If she is transfused with **A-positive** blood (red cells bearing the A antigen and the Rh antigen):
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> 1. **ABO incompatibility:** Her own plasma's anti-A antibodies will immediately recognise the donor red cells' A antigen as foreign and bind to them, causing the donor red blood cells to clump together (agglutinate) and subsequently rupture (haemolyse). This triggers a severe, potentially fatal **haemolytic transfusion reaction**, which can cause kidney failure, shock, and other systemic complications.
> …

Blood Group	Antigen on RBCs	Antibody in Plasma
A	A	Anti-B
B	B	Anti-A
AB	A and B	None
O	None	Anti-A and Anti-B

Q.Case study: An old woman is admitted to the hospital for a routine surgery. Her medical history reveals that she has blood group, B-negative. The hospital's blood bank has only A-positive and O-positive blood units available. She requires a blood transfusion during surgery.

Concept understanding — Blood Groups (ABO And Rh)

Blood Groups: ABO and Rh Systems

The ABO System

Working Out Transfusion Compatibility

The Rh System

Combining Both Systems …

Q.Case study: An old woman is admitted to the hospital for a routine surgery. Her medical history reveals that she has blood group, B-negative. The hospital's blood bank has only A-positive and O-positive blood units available. She requires a blood transfusion during surgery.

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