A CPDA-1 red cell unit with no additive solution has a hematocrit of 85%. What is the concern?

Too little plasma is left to supply glucose for the full 35-day shelf life

The unit will cause hemolysis of the recipient's own red cells

The unit will lose its ABO antigens

The unit is probably contaminated with bacteria

In CPD anticoagulant, citrate prevents clotting by:

Blocking platelet cyclooxygenase

Mannitol is included in some additive solutions, such as AS-1 and AS-5, to:

Reduce hemolysis by stabilizing membranes

Bind calcium to prevent clotting

Supply glucose for red cell glycolysis

Storage: anticoagulants and additives

5 ASCP MLS practice questions on Storage: anticoagulants and additives, part of Blood Banking. The first 5 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Easy
Red cells collected in CPDA-1, with no additive solution, expire after:
1. A42 days
2. B28 days
3. C35 days
4. D21 days
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Answer: C · 35 days
CPDA-1 adds adenine to the citrate, phosphate and dextrose of CPD, which extends red cell storage from 21 to 35 days. Adenine lets the cells keep making ATP. Red cells with an additive solution such as AS-1, AS-3 or AS-5 last 42 days. The storage limit is set so that enough red cells survive after transfusion.
- A: 42 days applies only when an additive solution is added.
- B: 28 days is the limit after irradiation, not the CPDA-1 shelf life.
- D: 21 days is the shelf life with CPD or CP2D, which lack adenine.
Question 2 · Hard
A CPDA-1 red cell unit with no additive solution has a hematocrit of 85%. What is the concern?
1. AToo little plasma is left to supply glucose for the full 35-day shelf life
2. BThe unit will cause hemolysis of the recipient's own red cells
3. CThe unit will lose its ABO antigens
4. DThe unit is probably contaminated with bacteria
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Answer: A · Too little plasma is left to supply glucose for the full 35-day shelf life
In red cells without an additive solution, the glucose comes from the plasma that remains. If too much plasma is removed, the cells run out of glucose before 35 days and survive poorly after transfusion. AABB therefore limits CPDA-1 red cells to a hematocrit of 80% or less. Red cells with an additive solution get their glucose from the additive.
- B: Donor red cells do not hemolyze the recipient's own cells.
- C: Storage does not remove ABO antigens.
- D: A high hematocrit does not indicate bacterial contamination.
Question 3 · Easy
In CPD anticoagulant, citrate prevents clotting by:
1. AActivating antithrombin
2. BActivating plasminogen
3. CBlocking platelet cyclooxygenase
4. DBinding calcium
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Answer: D · Binding calcium
Citrate chelates ionized calcium, which is needed at several steps of the coagulation cascade. Without free calcium the blood cannot clot in the bag. When citrated blood is transfused, the liver quickly metabolizes the citrate. Very rapid or massive transfusion can still lower the patient's ionized calcium.
- A: Activating antithrombin is how heparin works.
- B: Plasminogen activators dissolve clots; they are not used as anticoagulants in blood bags.
- C: Blocking cyclooxygenase is how aspirin affects platelets.
Question 4 · Medium
Mannitol is included in some additive solutions, such as AS-1 and AS-5, to:
1. ABind calcium to prevent clotting
2. BKeep 2,3-DPG at normal levels
3. CReduce hemolysis by stabilizing membranes
4. DSupply glucose for red cell glycolysis
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Answer: C · Reduce hemolysis by stabilizing membranes
Mannitol protects the red cell membrane and lowers hemolysis over 42 days of storage. AS-3 has no mannitol and uses citrate and phosphate instead. About 100 mL of additive solution is added after most of the plasma is removed. This gives red cells a hematocrit of about 55 to 65%, which flows easily.
- A: Citrate binds calcium.
- B: No additive solution keeps 2,3-DPG normal; it falls during storage.
- D: Dextrose, not mannitol, supplies energy for glycolysis.
Question 5 · Medium
Which ingredient of additive solutions such as AS-1 gives red cells the substrate they need to keep making ATP?
1. ASodium chloride
2. BCitrate
3. CAdenine
4. DMannitol
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Answer: C · Adenine
Red cells use adenine to rebuild their adenine nucleotide pool and keep making ATP. ATP supports membrane function and cell shape, and its level predicts how well the cells survive after transfusion. Dextrose in the same solution is the energy source for glycolysis. Together they allow 42 days of storage.
- A: Sodium chloride keeps the solution isotonic.
- B: Citrate is the anticoagulant and is not used to make ATP.
- D: Mannitol stabilizes the membrane; it is not used to make ATP.

Storage: anticoagulants and additives

Red cells collected in CPDA-1, with no additive solution, expire after:

A CPDA-1 red cell unit with no additive solution has a hematocrit of 85%. What is the concern?

In CPD anticoagulant, citrate prevents clotting by:

Mannitol is included in some additive solutions, such as AS-1 and AS-5, to:

Which ingredient of additive solutions such as AS-1 gives red cells the substrate they need to keep making ATP?