Question

Which blood type could be given as a transfusion for patient with AB blood when the RH factor is unknown

Answer 1

AB-

Step-by-step explanation:

All AB blood can receive AB-, but only AB+ can receive AB+, so it is safer to use AB- if the RH factor is unknown.

AB+ can receive AB+ or AB-

AB- can only receive AB-

Answer 2

Assuming the worst case scenario, which is that the patient does not have the Rhesus antigen, the patient can only accept blood from the blood groups of A-, B-, O-, AB-