MLT GlobeBlood Banking: Blood components & storage – page 5
109 Blood Banking MCQs on Blood components & storage with answers and explanations.
During storage of Thawed Plasma at 1–6 °C for up to 5 days, which coagulation factor falls the most?
The labile factor VIII declines most during refrigerated storage of thawed plasma, with a smaller fall in factor V. Fibrinogen and vitamin K–dependent factors remain stable.
Plasma labeled as Fresh Frozen Plasma (CPD anticoagulant, standard processing) must be placed in the freezer within what time after collection?
FFP is frozen within 8 hours of collection (or as approved for the collection system). Plasma frozen within 24 hours is labeled PF24 and has slightly lower factor VIII.
Solvent/detergent (S/D) treatment of pooled plasma does NOT reliably inactivate which virus?
Solvent/detergent disrupts lipid envelopes, so it kills enveloped viruses like HIV, HBV and HCV. Non-enveloped viruses such as parvovirus B19 and hepatitis A virus resist this treatment.
Why can 5% albumin be infused without ABO matching and with almost no risk of viral transmission?
Albumin is pasteurized at 60 °C for 10 hours, which inactivates viruses, and the fractionation process removes isoagglutinins. Irradiation and leukofiltration do not remove viruses.
Glycerol must be removed from frozen red cells before transfusion because, if infused, it would:
Glycerol-loaded cells are hypertonic; placed directly into plasma, water rushes in and they lyse. Stepwise washing with decreasing saline concentrations removes glycerol safely.
A red cell unit is divided into small neonatal aliquots with a sterile connecting device. The expiration date of each aliquot is:
A sterile connecting device keeps the system closed, so aliquots keep the original expiry. If the system is opened, a short expiry (24 hours for red cells) applies.
Apheresis platelets are volume-reduced by centrifugation in an open system for a small child. The product must be transfused within:
Volume-reduced platelets prepared in an open system expire 4 hours after processing. Volume reduction is used to limit fluid load or incompatible plasma.
An apheresis platelet unit with 3 days of dating left is irradiated today. Its new expiration is:
Irradiation does not shorten platelet dating, because it does not damage platelets meaningfully. Only irradiated red cells get a shortened expiry, because of potassium leakage.
In the buffy coat method of preparing platelets from whole blood (common in Europe), the first centrifugation is:
The buffy coat method starts with a hard spin, separating plasma, buffy coat and red cells. Pooled buffy coats then get a light spin to collect platelets. The platelet-rich plasma method starts with a light spin.
A blood bank refrigerator has an audible alarm. The alarm must be set to activate:
The alarm must sound early enough for staff to act before stored red cells go outside 1–6 °C. It must detect both high and low temperatures.
A red cell unit is returned unused to the blood bank 40 minutes after issue. It may be reissued if:
Returned units may re-enter inventory only if the container was not entered and the temperature was kept within limits (commonly 1–10 °C) according to validated procedures. A fixed time rule alone is not enough.
An FFP unit from a female donor has a green tint. Other inspection is normal. The most likely cause is:
Estrogen raises ceruloplasmin, a copper protein that can give plasma a green colour. Hemolysis gives a red or pink colour, and lipemia gives a milky appearance.
Plasma separated from a whole blood donation and shipped for fractionation into plasma derivatives, rather than transfusion, is called:
Recovered plasma comes from whole blood donations and goes to fractionation. Source plasma is collected by plasmapheresis specifically for fractionation.
Cryoprecipitate is prepared by:
When FFP is thawed slowly in the cold, fibrinogen, factor VIII, VWF and factor XIII remain as a precipitate. This is collected and refrozen as cryoprecipitate.
In an average adult without platelet consumption, one whole-blood-derived platelet unit is expected to raise the platelet count by about:
One whole-blood-derived unit raises the count in an average adult by about 5–10 × 10^9/L, which is why several units (or one apheresis unit) make up an adult dose.
One apheresis platelet unit contains roughly the same number of platelets as how many whole-blood-derived platelet units?
An apheresis unit contains at least 3 × 10^11 platelets, about the same as 4–6 pooled whole-blood-derived units, and it comes from a single donor.
Mannitol is added to SAGM additive solution mainly to:
SAGM contains saline, adenine, glucose and mannitol. Mannitol protects the membrane and reduces hemolysis during storage.
How is glycerol removed from thawed frozen red cells before transfusion?
Stepwise reduction of tonicity lets glycerol diffuse out slowly; sudden exposure to isotonic or hypotonic fluid would make glycerol-loaded cells swell and lyse.
Glycerolised red cells prepared by the high-glycerol (40%) method are stored at:
High-glycerol frozen RBCs are kept at ≤ −65 °C (mechanical freezer) for up to 10 years; low-glycerol cells need liquid nitrogen (≤ −120 °C).
An adult (BSA 2.0 m²) receives 4.0 × 10^11 platelets. Count rises from 10 × 10^9/L to 40 × 10^9/L at 1 hour. The corrected count increment (CCI) is:
CCI = increment (30,000/µL) × BSA (2.0) ÷ dose (4.0 × 10^11) = 15,000. A 1-hour CCI above about 7,500 indicates an adequate response.