Transfusion medicine Flashcards
What are RBC antigens also reffered to as?
agglutinogens
What type of antigens does Type O blood contain?
Type O contains neither A nor B antigens
List the frequencies of blood type and RH factors
Blood Groups Frequency (%) Type O 47 A 41 B 9 AB 3
Rh factor
Rh– 15
Rh+ 85
When are antibodies formed against the RBC antigens not present in the individual?
In the first year of life
What agglutinins are present in type A blood?
anti B
What blood type is a universal donor?
O
What blood type is a universal recipient?
AB
What components are immediately separated when a blood donation is given?
Fresh frozen plasma (FFP)
Packed red blood cells (PRBCs)
granulocytes
platelets
Which minor blood fractions are pooled from multiple blood donors?
albumin
gamma globulin
cryoprecipitate
fibrinogen
Within 24 hours after donation blood is devoid of?
normally functioning platelets and some clotting factors.
specialized storage and transfusion techniques optimize the survival and availability of each component.
What are packed RBCs?
Most plasma is removed
Contains the same red cell mass as 1 unit of whole blood at half the volume and twice the hematocrit
How much does 1 unit of PRBCs raise the hemoglobin and hematocrit?
One unit raises the hematocrit 3% in an adult, or increases the hemoglobin by 1 g/dL on average
What are washed RBCs?
Removes leukocytes, platelets, and proteins, and reduces the titer of anti-A and anti-B antibodies, permitting safer transfusion of type O PRBCs in non-O recipients
When are WRBCs used?
Used to prevent allergic reactions in IgA-deficient patients
Used in patients who have had febrile (nonhemolytic) reactions to previous transfusions as a result of leukocyte antibodies or IgA sensitization
When are Leukocyte reduced RBCs used?
Used to reduce likelihood of febrile reactions, immunization to leukocytes, and disease transmission
Used in patients who are chronically transfused, potential transplant recipients, and those with more than one febrile transfusion reaction in the past.
How much of the US blood supply is leukocyte reduced?
Currently about 60-75% of U.S. blood supply is leukoreduced
What does irradiation do to donated RBCs?
Irradiation destroys the donor lymphocytes’ ability to respond to the host’s foreign antigens
What risk do irradiated RBCs reduce?
Reduces the risk of graft vs. host disease in susceptible patients
When are irradiated RBCs used?
Used for bone marrow transplant donors or recipients, directed donations from family members, and patients with cellular immune deficiency
What is compatibility matching or cross referencing?
The donor’s RBCs and serum are mixed with the recipient’s RBCs and serum to identify the potential for a transfusion reaction from minor antigens not recognized by ABO and Rh typing
Endpoint is the presence of RBC agglutination or hemolysis
A cross match test is done on a donor and recipient blood. The resulting mixture clumps. Is the blood compatible or not?
Not compatible
Do plasma products need to be cross matched?
Plasma products do not need to be crossmatched but should be ABO compatible because WBCs and platelets have ABO antigens.
What is a direct Coombs test?
Done on a sample of RBCs from the body to detect antibodies that are already attached to RBCs. Can be antibodies from the patient or those received from a blood transfusion
When is a direct Coombs test done in regards to a newborn baby?
Done on a newborn baby with Rh+ blood whose mother was Rh-. Tests whether the mother made antibodies and if the antibodies moved through the placenta to the baby.