Blood Components Flashcards
1
Q
What is the Buffy coat in terms of blood components?
A
White blood cells and platelets
2
Q
What are red cell donations commonly used for?
A
Used to replace lost red cells due to acute anaemia where alternatives are inappropriate or ineffective.
3
Q
How much approximately is a unit of packed red cells?
A
£125
4
Q
What temperature at packed red cells stored at?
A
Between 2 and 6 degrees
5
Q
What is the maximum storage time for packed red cells?
A
28 to 49 days
6
Q
What is the maximum storage time for packed red cells according to NHSBT?
A
Up to 35 days
7
Q
How long are irradiated packed red cells allowed to be stored for?
A
14 days
8
Q
How long can washed red cells be stored for?
A
14 days
9
Q
How long can red cells be out of the blood fridge if they are being returned to the fridge?
A
30 minutes
10
Q
If packed red cells are out of the blood fridge for longer than 30 mins, how quickly but it be donated to a recipient?
A
Within 4 hours of leaving the fridge
11
Q
What is irradiation of cells?
A
Stops lymphocytes from being able to reproduce but it does not greatly affect other blood cells. Can cause damage to the membrane of red cells.
12
Q
How does irradiation affect red cells?
A
IT can cause damage to membranes.
13
Q
When are Granulocytes often needed in a donation?
A
Often in patients with life-threatening soft tissue or organ infection with bacteria or fungi.
In people with low neutrophil counts.
14
Q
When do people often have a low neutrophil count?
A
After chemotherapy
15
Q
What must happen to Granulocyte donations before they can be accepted and why?
A
They must be irradiated due to the high risk of white cell engraftment and graft vs host disease.
16
Q
What is engraftment?
A
New cells are working properly and starting to rebuild your immune system.
17
Q
How much does a unit of pooled Granulocytes cost?
A
£1166
18
Q
What temperature are granulocytes stored at?
A
20 to 24 degrees
19
Q
What is the maximum storage time for granulocytes?
A
24hrs
20
Q
How long can Granulocytes be outside of their storage temperature?
A
No specific rules given
21
Q
When is a platelet donation often needed?
A
Used for treatment or prevention of people with low platelet count or platelet dysfunction.
22
Q
What is the term for low platelet count?
A
Thrombocytopenia
23
Q
What does a standard dose of platelets cost?
A
£193.14
24
Q
What is the storage temperature for platelets?
A
20 to 24 degrees Celsius
25
Why are platelets stored at a relatively high temperature?
They are activated at lower temperatures
26
What is the risk with storing platelets at a relatively high temperature?
There is higher risk of contamination due to being stored at the higher temperature.
27
What is the maximum storage time for granulocytes?
5 days or 7 days if in conjugation with detection or reduction.
28
What must happen to granulocytes during storage?
Agitation
29
Why must granulocytes be agitated during storage?
This ensures that the platelets are continuously oxygenated.
30
Why must bags strong granulocytes be gas permeable ?
Allows them to be continuously oxygenated and for carbon dioxide to be expelled. Also press platelet granule release and platelet lysis.
31
How long can granulocytes be outside of their storage temperature?
30 mins
32
How quickly must granulocytes be donated if they have been outside of their storage temperature?
6 hours
33
What patients is frozen fresh plasma used to treat?
Treats and prevents bleeding due to multiple clotting factor deficiencies such as with liver disease or large haemorrhages.
34
What should be used in reversal of warfarin?
Octaplex
35
Why is Octaplex used instead of fresh frozen plasma to reverse warfarin?
It is much faster and more effective.
36
What does a standard bag of fresh frozen plasma cost?
£31.40
37
How is cryoprecipitate formed?
By thawing fresh frozen plasma at 4 degrees.
38
When is cryoprecipitate often donated?
Used in bleeding associated with hypofibrinogenanaemia and congenital or acquired dysfinbrnogenanaemia.
39
How much is a bag of cryoprecipitate?
Usually £175 wish
40
What is the storage temperature of fresh frozen plasma and cryoprecipitate?
Below -25 degrees celsius
41
What is the maximum storage time after donation for fresh frozen plasma and cryoprecipitate?
36 months
42
How long can fresh frozen plasma be stored at 2-6 degrees celsius for?
24 hours
43
How long after leaving their controlled temperature should fresh frozen plasma and cryoprecipitate be donated?
Within 4 hours
44
Why must cry e used within 4 hours of thawing?
If not the clotting factors will begin to precipitate and become useless.
45
What would be the benefits of using whole blood donations?
Would be much easier than donating multiple bags of different component types.
46
What are the possible issues with whole blood donations?
Platelet life span would be greatly reduced after being in cold storage.
47
What is done to plasma derivatives to reduce the risk of transfusion transmitted viruses?
Pathogen inactivation
48
What are plasma derivatives made from?
A large pool of donated plasma
49
Why are all plasma derivative components imported?
To reduce the risks of vCJS and prions
50
What is the licensed medicinal product of solvent detergent fresh frozen plasma?
Octaplas
51
What process must be carried out on solvent detergent FFP before they can be donated?
SD processing
52
What is the purpose of carrying out SD processing on Solvent detergent FFP?
Inactivates bacteria and most encapsulated viruses.
53
Where are the donations for Octaplas from and why?
Countries with a low risk of vCJD
54
What is the pooling process used for when forming Octaplas?
This leads to more standardised concentrations of clotting factors in each pack.
55
What patients is Octaplas often given to?
Patients with inherited rare clotting factor deficiencies where a clotting factor concentrate is not yet available.
56
What is the average cost of Octaplas?
£50
57
What are the 2 possible solutions of human albumin solution?
4.5-5%
| 20%
58
What is 5% human albumin solution used for?
To replace subacute plasma volume caused by burns, pancreatitis or trauma.
59
What is 20% human albumin solution used for?
Patients with liver cirrhosis, nephrotic syndrome, portal hypertension.
60
What are clotting factor concentrates used to treat?
Most inherited coagulation deficiencies.
61
What is the only licensed treatment of congenital hypofibrinogenemia in the UK?
Fibrinogen concentrate
62
What is Prothrombin complex concentrate used to treat?
Rapid reversal of warfarin overdose.
63
What is the name for the changes that occur in the red cells during storage?
Storage lesions
64
What happens to the sodium potassium pump during storage lesions and what does this lead to?
It is immobilised within red cell membrane causing a decrease in intracellular K+ but an increase in cytoplasmic Na+.
Acidosis may occur due to low pH levels.
65
What effect does lipid peroxidation caused by storage lesions have ?
Oxidative stress to band 3 structures.
Morphological and structural molecular changes.
Sphereochinocytes
Osmotic fragility
66
What is Sphereochinocytois?
Red cells become more spherical.
67
What can make storage lesions worse?
Gamma irradiation
68
Why should cardiac surgery in children use transfusions with blood that is less than 5 days old?
Blood cells that have been stored for a long time tend to have increased levels of K+ and may be associated with neonatal arthritis and hyperkalaemia.
69
How quickly does blood coagulate after venesection?
Within minutes
70
What is venesection?
Removal of blood from the circulatory system
71
What sterile anticoagulant are blood bags manufactured to include?
Citrate Phosphate Dextrose (CPD)
72
How does CPD work as an anticoagulant in fresh whole blood?
It binds to and removes calcium ions to prevent the clotting cascade.
73
What is the purpose of the phosphate in CPD anticoagulant for fresh whole blood?
It counteracts the loss of phosphate during storage and improves viability.
74
What is the purpose of the dextrose in CPD anticoagulant for fresh hole blood?
Prevents loss of ATP
75
What is the additive solution added to red blood cells to combat the effects of storage?
Saline-Adening-Glucose (SAG)
76
What is the purpose of the saline in the SAG added to red blood cells?
Maintains blood volume and osmolarity
77
What is the purpose of the adenine in SAG added to red blood cells?
Restores cell shape, ATP concentration and viability.
78
What is the purpose of the Glucose in SAG added to red blood cells?
Prevents loss of ATP and enables longer term storage and better viability.
79
What are some of the special requirements for blood transfusion?
Leucodepletion
Irradiation
Phenotyping
CMV testing
80
What is Leucodepletion?
The removal of white cells from a red cell unit.
81
Why are some blood donations leucodepleted?
Transfused leukocytes can sometimes induce immunosuppressive changes in the recipient
82
How does Leucodepletion aid transfusion?
Reduces the incidence of febrile transfusion reactions.
Reduces the transmission of CMV.
Reduces the incidence of postoperative infection and reoccurrence of cancer.
83
How is Leucodepletion of samples carried out?
Filtration through multiple layers of synthetic polyester non-woven fibres that selectively retain white cells.
84
Why is irradiation of transfusion material often needed?
Some left over white cells can engirt and detect the host as 'foreign' leading to transfusion associated graft versus host diseases. Irradiation stops this by inactivating lymphocytes.
85
In cellular terms, what does irradiation do?
Inactivates lymphocytes
86
What issues may irradiation of a donation cause?
Irradiation accelerates the rate of potassium leakage from red cells so shelf life shortens to 14 days.
87
Why is a sample often phenotypes?
To prevent potentially life threatening transfusion reactions in those patients with all-antibodies or to prevent patients from developing all-antibodies.
88
For what type of patients is a donation phenotypes?
For patients with alloantibodies or autoantibodies.
For patients who are transfusion dependent.
Women of child bearing age.
89
What type of patients may need fresh blood?
Those patients who would be affected by increased potassium levels. Or patents who are transfusion dependent.
90
How does fresh blood help patients who are transfusion dependent?
It reduces the number of transfusions they need.
91
What is the purpose of treating plasma with methylene blue?
It is a method of pathogen inactivation.
92
What are the issues with treating plasma with methylene blue?
Can be associated with allergic reactions.
93
How does methylene blue inactive pathogens?
MB is added and the unit is exposed to visible light in an illuminator for approx 30 mins. This forms free radicals and oxidative species that damage nucleic acids, preventing pathogen replication.
94
What are the 5 steps for establishing compatibility of a donation?
1) Sample acceptance
2) ABO and RhD grouping
3) Antibody screening
4) Serolgoical Crossmatch
5) Emergency Issue
95
What is the purpose of antibody screening in samples?
Looking for any antibodies that have been made to the red cells. Checking for atypical antibodies.
96
What is serologic crossmatching ?
Donor red cells mixed with recipients plasma to see if they are matched.
97
What are the advantages of electronical issue?
Fast, avoids transfusion days, reduces red cell wastage, reduces hands-on work.
98
What are the disadvantages of electronic issue?
Must have a reliable and validated lab info management system.
Cannot perform if IT failure occurs.
99
What are blood components labelled with?
```
NHSBT donor ID
Component type and storage condition
Volume
Location of the NHSBT site where it was produced
Blood group
Expiry date
Additional testing result information
Donation date
```
100
What is the purpose of monitoring storage f blood components?
Minimises the risk to recipients from bacterially contaminated units.
101
What is traceability of a donation unit?
The ability to trace each individual unit of blood or blood component derived from the donor to its final destination, whether this is a recipient, a manufacturer of medicinal products or disposal.
102
How long is traceability for each donation sample stored for?
At least 30 years
103
What is recall of a sample?
All products and components which are considered to pose a risk to patients are withdrawn from use.
104
What is the payment to blood donors in the UK?
None
105
How many different blood components are there?
5
106
What are the advantages of Octoplas compared to fresh frozen blood?
It is more standardised because it is prepared from lots of donations.
It has less variable clotting factor concentrations.
It is associated with a lower incidence of transfusion reactions.
107
Why is fresh blood given to neonates?
Red cells don't have their own nuclei so begin to deteriorate and the Na+/K+ pump is damaged. Giving older cells to neonates may cause an extreme increase in blood k+ which can be detrimental to babies.
