The "Universal Donor" blood group is:

Appeared in: RML Lucknow - 2021

Explanation

O negative blood is called the universal donor because its red blood cells have no A, B, or RhD antigens on their surface.
The absence of these antigens means it will not trigger an immune response (agglutination) when transfused into a person with any other blood type.
This makes it the safest option for emergency transfusions when the recipient's blood type is unknown.

Option A: AB positive blood is the 'universal recipient,' not the universal donor. Its red blood cells have both A and B antigens, as well as the Rh antigen, so it can only be donated to other AB positive individuals.
Option B: AB negative blood has both A and B antigens on its surface. This means it can only be donated to individuals with AB blood type (positive or negative) without causing an immune reaction.
Option D: O positive blood lacks A and B antigens but possesses the Rh (D) antigen. It cannot be given to Rh-negative individuals (e.g., A-, B-, AB-, O-) as their immune system would produce anti-Rh antibodies, leading to a transfusion reaction.

Clinical Relevance

Nursing practice connection: Knowing Blood group compatibility and the concept of universal donors in blood transfusion helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
In emergency situations, such as trauma or massive hemorrhage, O-negative blood is transfused when there is no time to type and crossmatch the patient's blood.
Administering incompatible blood can lead to a life-threatening acute hemolytic transfusion reaction, causing fever, chills, kidney failure, and shock.
What if? If an O-negative patient needs blood, they can ONLY receive O-negative blood. This is because their plasma contains anti-A, anti-B, and potentially anti-Rh antibodies (if previously sensitized), which would attack any other blood type.

How to Approach the Question

Identify the key term in the question: 'Universal Donor'.
Recall the definition of a universal donor: a blood type that can be safely transfused to a person with any other blood type.
Understand the basis of blood compatibility: The donor's red blood cells must not have antigens that the recipient's plasma antibodies will attack.
To be 'universal', the donor's blood must lack all major antigens: A, B, and Rh.
Evaluate the options: 'O' blood type lacks A and B antigens. 'Negative' blood type lacks the Rh antigen.
Combine these facts: O negative blood lacks A, B, and Rh antigens, fitting the definition of a universal donor. Select this option.

Concept Tested & Keywords

Concept Tested: Blood group compatibility and the concept of universal donors in blood transfusion.
Stem keywords: Universal Donor, blood group
Lead-in keywords: is
Negative lead-in flag: false

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