Storage: expiration

6 ASCP MLS practice questions on Storage: expiration, part of Blood Banking. The first 6 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

1. Question 1 · Easy

   Fresh frozen plasma stored at -18 °C or colder expires after:

   1. A10 years
   2. B12 months
   3. C6 months
   4. D5 years

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   Answer: B · 12 months

   FFP and cryoprecipitate stored at -18 °C or colder expire 12 months after collection. With FDA approval, plasma stored at -65 °C or colder may be kept longer. Red cells frozen with glycerol at -65 °C or colder last 10 years. Once thawed, plasma expires much sooner.

   • A: 10 years is the shelf life of glycerolized frozen red cells.
   • C: 6 months is shorter than the FFP shelf life.
   • D: 5 years is not a standard FFP shelf life.

2. Question 2 · Hard

   A red cell unit due to expire in 20 days is irradiated today. Its new expiration is:

   1. A20 days from today
   2. B24 hours from now
   3. C28 days from today
   4. D48 days from today

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   Answer: A · 20 days from today

   Irradiated red cells expire 28 days after irradiation or on the original expiration date, whichever comes first. Here the original date, 20 days away, comes first, so it does not change. The limit exists because irradiation damages the membrane and increases potassium leak. Irradiated platelets keep their original expiration.

   • B: 24 hours applies to units opened in an open system, not to irradiation.
   • C: 28 days from today would extend the unit past its original expiration.
   • D: 48 days adds the two periods together, which is never done.

3. Question 3 · Medium

   Thawed cryoprecipitate pooled in an open system expires after:

   1. A24 hours
   2. B4 hours
   3. C5 days
   4. D6 hours

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   Answer: B · 4 hours

   Opening a bag to pool units creates a risk of bacterial contamination, so an open-system pool expires 4 hours after pooling. A single thawed unit, or a pool made in a closed system before freezing, expires 6 hours after thawing. Thawed cryoprecipitate is kept at 20 to 24 °C. The pool label must show the new expiration time.

   • A: 24 hours applies to thawed FFP and red cells in an open system.
   • C: 5 days applies to thawed plasma, not cryoprecipitate.
   • D: 6 hours applies to single units and closed-system pools.

4. Question 4 · Hard

   Four whole blood-derived platelet units are pooled in an open system at 10:00 on day 3 of storage. When does the pool expire?

   1. A16:00 the same day
   2. B10:00 the next day
   3. C14:00 the same day
   4. DAt the original expiration of the oldest unit

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   Answer: C · 14:00 the same day

   Pooling in an open system breaks the sterile seal, so the pool expires 4 hours after pooling: here 14:00. Platelets pooled before storage in an FDA-approved closed system keep the original expiration. The pool label shows the new time and a pool identification number. Bacterial growth is the main risk in opened room-temperature components.

   • A: 6 hours applies to thawed cryoprecipitate, not opened platelet pools.
   • B: 24 hours is the limit for opened red cells, not platelets.
   • D: The original expiration applies only to closed-system prestorage pools.

5. Question 5 · Medium

   FFP collected in a closed system is thawed but not used. It may be relabeled 'Thawed Plasma' and kept at 1 to 6 °C for up to:

   1. A5 days from thawing
   2. B24 hours from thawing
   3. C35 days from thawing
   4. D14 days from thawing

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   Answer: A · 5 days from thawing

   Thawed FFP expires after 24 hours, but if it was collected in a closed system it can be relabeled 'Thawed Plasma' and kept for 5 days from thawing. Factors V and VIII fall somewhat during this time, but the other factors stay at useful levels. Many trauma centers keep thawed group A or AB plasma ready for immediate use. This also reduces plasma wastage.

   • B: 24 hours is the limit for thawed FFP before relabeling.
   • C: 35 days is a red cell shelf life.
   • D: 14 days is longer than allowed for thawed plasma.

6. Question 6 · Hard

   Surgery for a patient with a rare antibody was booked for Tuesday but is postponed, and at 09:00 on Wednesday the surgeon asks for blood. The blood bank log shows: unit 1, red cells washed in an open system at 07:00 on Tuesday; unit 2, a frozen rare red cell unit thawed and deglycerolized in a closed automated system and resuspended in AS-3 at 10:00 on Monday; unit 3, a second frozen rare unit deglycerolized in an open system at 10:00 on Monday; unit 4, four whole blood-derived platelet units pooled in an open system at 18:00 on Tuesday. All were stored correctly. Which unit can still be issued?

   1. AUnit 1, the washed red cells
   2. BUnit 2, the closed-system deglycerolized red cells
   3. CUnit 3, the open-system deglycerolized red cells
   4. DUnit 4, the open-system platelet pool

   Answer and explanation in LearnFree account