Question

A 55 year old male accident victim in casualty urgently needs blood. The blood bank is unable to determine his ABO group, as his red cell group and plasma group do not match. Emergency transfusion of the patient should be with

• A. RBC corresponding to his red cell group and colloids/crystalloid.
• B. Whole blood corresponding to his plasma group.
• C. O positive RBC and colloids/crystalloid.
• D. AB negative whole blood.

Hint:

When ABO grouping is unclear, give O group RBCs, which carry no A or B antigen, with fluids for volume.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
A trauma patient needs blood right away, but the blood bank cannot fix his ABO group because his red cell typing and his plasma (reverse) typing give conflicting results. We need the safest way to transfuse him without waiting for the discrepancy to be resolved.

Step 2: Key Concept:
When ABO typing is unclear and transfusion cannot wait, the rule is to use group O red cells, since they carry neither A nor B antigen and will not be attacked by anti-A or anti-B antibodies in the recipient's plasma, whatever his true group turns out to be. Plasma volume is replaced separately with colloids or crystalloids, not with type specific whole blood, since the correct group is not yet known.

Step 3: Detailed Explanation:
Giving RBCs matched to his stated red cell group is not safe here, because the red cell group itself is in question, that is exactly what does not match the plasma group.
Giving whole blood matched to his plasma group is also wrong, because whole blood carries donor plasma and donor red cells together, and using an unconfirmed group risks a hemolytic reaction.
AB negative whole blood is the universal plasma donor type for plasma alone, but it is not the standard choice for the red cell component, and whole blood is rarely used now, packed red cells plus separate fluids are preferred.
O group red cells lack A and B antigens, so they cannot be destroyed by anti-A or anti-B in the patient's own plasma, this makes them a safe, uncrossmatched emergency choice while the blood bank keeps working out the true group. Volume is topped up with colloids or crystalloids, which carry no red cell antigens at all.

Step 4: Final Answer:
The safest emergency choice, when the ABO group cannot be confirmed, is O group red cells together with colloids or crystalloids for volume support.