Blood Bank ASCP Study Guide
Can an autologous donor donate blood at 4pm on Monday if she is having surgery at 10am on Wednesday?
No, the minimal allowable time between the last donation and surgery is 72hrs
At what temperature should whole blood or red blood cell units be kept at during transportation?
1-10 °C
How many doses of RhIG should be administered if the calculated amount of fetal whole blood volume in maternal circulation was 28 mL?
2 doses - when calculating RhIG dosage, facilities always add one extra does to the calculated does for an added margin of safety. Each does is effective in treating 30 mL fetal whole blood.
Unless an alternative has been approved by the FDA, what is the expiration and storage temperature of rejuvenated (non-frozen) RBC's?
24hrs, 1°C to 6°C
If the unit is going to be transfused within the collection facility, autologous blood must always be tested for which of the following before transfusion?
ABO and Rh
The major crossmatch is performed using:
Donor's red cells and recipient's serum or plasma
The MOST reliable method for determining the appropriate dosage of Rh immune globulin to give to an identified Rh immune globulin candidate after delivery is:
Flow cytometry
Delayed hemolytic transfusion reactions are usually caused by antibodies directed against what blood group system?
Kidd - both JKa JKb are often responsible because the antibody titers increase and then quickly decrease after immune stimulation
Which of the following tests has been recommended by the FDA to replace the HIV-1 p24 antigen test in the screening of donated blood for infectious disease?
HIV-1 NAT
One risk associated with patients that require chronic transfusions is:
Iron overload - A long term complication of RBC transfusion is iron overload. Each unit of red cells contains 225mg of iron, which puts these patients at risk for iron overload.
When performing an antibody screen, both the screen cells are 4+ at immediate spin and W+ at AHG. The antibody panel shows 4+ at immediate spin and W+ reactions at AHG and there is no specific match to the reaction pattern. The auto control is negative. What would be a logical next step?
Repeat testing using warmed patient sample/reagent and just do AHG reading. This is a strong cold antibody causing activation and binding of the antibody to take place at room temp or colder. warming the sample/reagents and eliminating this phase will prevent the antibody from binding.
Why is weak D testing not performed on pregnant women?
Weak D testing is not required as part of a prenatal evaluation, as it is not possible to differentiate weak D from partial D serologically
which organism is MOST likely responsible for septic reactions associated with RBC transfusions?
Yersinia enterocolitica
blood type O
anti-A and anti-B will show no agglutination in the forward type. A cells and B cells will show agglutination in the reverse type
Which of the following criteria for donor RBC should be used for an EXCHANGE TRANSFUSION related to both HDFN due to anti-D and ABO HDFN?
irradiated - to prevent GVHD other criteria: RBCs < 7 days old resuspended in group AB FFP, Hgb-S neg blood, group O Rh neg blood, CMV reduced risk products, blood lacking antigens corresponding to maternal antibody, compatible crossmatch with maternal serum
Which is the MOST IMPORTANT first step to take when a patient is transfused with uncross-matched RBCs that turn out to be incompatible?
stop any transfusion in progress - severity of hemolytic transfusion reactions partly depends on the volume of red cells transfused
Which of the following is the most commonly encountered presenting sign of a delayed hemolytic transfusion reaction (DHTR)?
unexplained decrease in Hgb or Hct - reaction caused by a secondary immune response which requires time for enough antibody to be produced by the patient to cause signs and symptoms of extravascular hemolysis.