MLT GlobeBlood Banking: Donor selection & processing – page 4
75 Blood Banking MCQs on Donor selection & processing with answers and explanations.
During plateletpheresis, a donor reports tingling around the lips and fingers. What is the best action?
Citrate anticoagulant binds calcium, causing mild hypocalcemia symptoms. Slowing the procedure and giving oral calcium usually relieves symptoms. More citrate would worsen them.
Two days after donating, a donor calls to report fever and diarrhea that started the day after donation. What should the blood centre do first?
Post-donation information may mean the donor was infected at donation. Components are quarantined or retrieved while the risk is assessed; permanent deferral is not automatic.
Donor samples are tested for HIV RNA in minipools of 16. A pool is reactive. What is the next step?
A reactive pool is resolved by testing each sample individually to find the reactive donation. Non-reactive donations from the pool can then be released.
A male donor takes finasteride for hair loss. Why is he deferred for 1 month after the last dose?
Finasteride is teratogenic; it blocks 5-α-reductase and may affect male fetal genital development. A 1-month deferral lets the drug clear before donation.
Compared with whole blood donors, donors of two red cell units by apheresis must meet:
Double red cell donation removes about twice the red cell mass, so a higher hematocrit (commonly ≥ 40%) and higher weight/height limits are required.
Transfusion-transmitted syphilis is rare mainly because Treponema pallidum:
T. pallidum does not survive long at refrigerator temperature, and donors are also screened serologically.
A donated unit is repeatedly reactive in the anti-HCV screening test. What happens to the unit?
Units that are repeatedly reactive for a mandatory infectious marker must not be transfused. The donor is deferred and counseled according to confirmatory results.
Malaria can be transmitted by red cell transfusion mainly because Plasmodium parasites:
Malaria parasites live inside red cells and can survive refrigerated storage, so any red-cell-containing component can transmit them. This is why donors are screened in endemic countries.
In the United States, which donor screening test may be performed only once per donor rather than on every donation?
FDA allows a single negative test for T. cruzi (Chagas disease) antibody to qualify a donor for future donations. HIV, HBV and HCV markers are tested on every donation.
Why is hydroxyethyl starch (HES) added during granulocyte collection by apheresis?
HES causes red cell rouleaux and faster sedimentation, improving separation from granulocytes. Neutrophil release is increased by G-CSF or corticosteroids, not HES.
Red cells collected by intraoperative blood salvage and washed with saline are kept at room temperature. They must be transfused within:
Washed salvaged red cells held at 20–24 °C must be infused within 4 hours because of bacterial growth risk. If refrigerated within 4 hours, they may be kept up to 24 hours.
In acute normovolemic hemodilution, units collected before surgery are reinfused in which order?
The first unit collected has the highest hematocrit and most platelets and clotting factors. It is saved for last, when bleeding has stopped and it gives the most benefit.
A collection bag contains 63 mL of CPD for 450 mL of blood. Only 300 mL will be collected. How much anticoagulant should be removed?
Needed anticoagulant = (300 ÷ 450) × 63 = 42 mL. The amount to remove is 63 − 42 = 21 mL. Keeping too much anticoagulant would harm red cells.
A whole blood collection took 18 minutes to finish. Many blood centres would NOT use this unit to prepare:
Slow collections may activate platelets and coagulation. Commonly, units collected over 15 minutes are not used for platelets, and those over 20 minutes are not used for plasma for transfusion.
A donor received long-acting injectable HIV pre-exposure prophylaxis (PrEP). Under current FDA guidance, the donor is deferred for:
Injectable PrEP can delay antibody and NAT detection of HIV for a long time, so FDA requires a 2-year deferral. Oral PrEP or PEP needs a 3-month deferral.