Final answer:
An AB- patient can receive blood plasma from any ABO type but should receive Rh- blood to avoid reactions. In emergencies, O- blood is the safest option due to the absence of A, B, and Rh antigens.
Step-by-step explanation:
An AB- patient is considered a universal recipient in the ABO blood group system. Since this patient's blood contains both A and B antigens, they can theoretically receive any ABO blood type without concern for anti-A or anti-B antibodies causing a reaction. When it comes to the Rh factor, an AB- patient can safely receive blood from Rh- donors but should not receive Rh+ blood, as the Rh+ blood contains the Rh antigen that could cause an immune reaction in an Rh- patient.
Nevertheless, in emergency situations, an AB- patient might receive O- blood, which does not have A, B, or Rh antigens, making it the safest option when the patient's Rh factor is not known. To ensure the safety and compatibility of the plasma transfusion, despite emergency situations, it is always ideal to cross-match blood types first.