Final answer:
It is false that Kell, Lewis, and Duffy blood typing is always required before a transfusion. These are only needed if there's a risk for antibodies to these antigens. In emergent situations, type O blood can be used without full cross-matching.
Step-by-step explanation:
It is false that blood typing for the Kell, Lewis, and Duffy factors is always done before a blood transfusion. While cross matching to determine blood type is crucial to avoid transfusion reactions, the full typing for Kell, Lewis, and Duffy is not always required unless the patient has or is at risk for antibodies to these antigens. In emergency situations where there is an immediate threat to life due to hemorrhage, type O blood may be used without the typical cross-matching process. However, in non-emergency settings, a pretransfusion blood typing test is performed to ensure compatibility and prevent potentially life-threatening transfusion reactions. This testing includes ABO and Rh (D antigen) typing, and an antibody screening test to check for antibodies that the patient might have against antigens outside the ABO and Rh systems.