MLT GlobeBlood Banking: Blood components & storage – page 2
109 Blood Banking MCQs on Blood components & storage with answers and explanations.
Platelets have the highest risk of bacterial contamination among blood components mainly because they are:
Storage at 20–24 °C allows skin bacteria to multiply, unlike refrigerated red cells or frozen plasma.
In a stable adult without bleeding, one red cell unit is expected to raise the hemoglobin by about:
One unit usually raises hemoglobin by about 10 g/L (1 g/dL) and hematocrit by about 3% in an average adult.
Which intravenous fluid may be given through the same line as red cells?
Only normal saline is routinely compatible with red cells. Dextrose solutions cause hemolysis and lactated Ringer's contains calcium that can cause clotting.
Apheresis platelets stored at 20–24 °C with agitation, and with no additional bacterial risk-control step, expire after:
Conventional room-temperature platelets have a 5-day shelf life because of the risk of bacterial growth. Seven-day dating is allowed only when an extra bacterial risk-control strategy is used.
Which coagulation factor is NOT present in useful amounts in cryoprecipitate?
Cryoprecipitate contains fibrinogen, factor VIII, von Willebrand factor, factor XIII and fibronectin. Factor IX stays in the cryo-poor supernatant, so cryo cannot treat hemophilia B.
Frozen plasma and cryoprecipitate are thawed at:
These components are thawed at 30–37 °C in a water bath (in a protective overwrap) or an approved thawing device. Higher temperatures denature proteins; lower temperatures thaw too slowly.
Four-factor prothrombin complex concentrate, used for urgent warfarin reversal, contains factors:
Four-factor PCC contains the vitamin K–dependent factors II, VII, IX and X (plus proteins C and S). These are the factors reduced by warfarin.
Red cells frozen with a glycerol cryoprotectant and stored at −65 °C or colder have a maximum shelf life of:
Frozen red cells may be stored for 10 years (longer for rare units if approved). This makes freezing useful for storing rare phenotypes.
How does the blood bank confirm that a component placed in the irradiator actually received irradiation?
Radiation-sensitive indicator labels change colour or show a mark when the required dose is reached. They give visual proof for each unit; lab tests are not used for this.
Which component does NOT need to be irradiated, even for a patient at high risk of TA-GVHD?
Freezing and thawing kills lymphocytes in plasma, so FFP and cryoprecipitate do not cause TA-GVHD. Cellular components, especially granulocytes, contain viable lymphocytes and need irradiation.
Blood components such as red cells, plasma and platelets are separated from whole blood mainly by:
Centrifuging whole blood separates red cells, platelets and plasma into layers according to their density and size.
The main purpose of a red cell transfusion is to:
Red cells are given to improve oxygen delivery in symptomatic anemia or blood loss. Plasma, platelets and albumin are used for the other needs.
Fresh frozen plasma is used because it contains:
Freezing plasma soon after collection keeps all clotting factors, including the unstable factors V and VIII.
Where should red cell units be stored before transfusion?
Red cells need a dedicated blood bank refrigerator with continuous temperature monitoring and alarms. Domestic refrigerators are not controlled, and freezing without glycerol lyses red cells.
Bleeding in a patient with severe hemophilia A is best treated with:
Hemophilia A is factor VIII deficiency, so bleeding is treated with factor VIII concentrate (recombinant or plasma-derived).
In CPD anticoagulant-preservative, sodium phosphate acts mainly as a:
Phosphate buffers the acid produced during storage, which helps preserve 2,3-DPG. Citrate binds calcium and dextrose supplies energy.
Platelet concentrates kept at 20–24 °C with agitation have what standard shelf life, unless an approved bacterial risk-control method is used?
Room-temperature storage risks bacterial growth, so the routine limit is 5 days; extension to 7 days is permitted only with approved bacterial detection or pathogen reduction. 35 days applies to red cells.
Whole blood collected into CPDA-1 and stored at 2–6 °C has a shelf life of:
Adenine in CPDA-1 extends storage to 35 days. CPD alone gives 21 days, and red cells in additive solutions such as SAGM keep for up to 42 days.
Which clotting factor is NOT concentrated in cryoprecipitate?
Cryoprecipitate contains fibrinogen, factor VIII, von Willebrand factor, factor XIII and fibronectin. Vitamin K-dependent factors such as X and IX stay in the supernatant plasma.
In current practice, cryoprecipitate is transfused mainly to replace:
Cryoprecipitate is rich in fibrinogen, factor VIII, vWF and XIII. Hemophilia A and vWD now use factor concentrates, so its main use is hypofibrinogenemia, e.g. in massive bleeding.