Blood Transfusion Flashcards
1
Q
Reasons to transfer blood
A
Bleeding (Mainly)
Failure of production
2
Q
Features of antigens of blood groups
A
Red cell antigens expressed on cell surface (proteins, sugars, lipids)
Can provoke antibodies
3
Q
What is an antigen?
A
Something that provokes an immune response
4
Q
Blood group types
A
Type A
Type B
Type AB
Type O
5
Q
Antigens of the ABO blood groups
A
ABO - glycosyltransferase A and B - transferase enzymes A = N-acetyle-galactosamine B - galactose 0 - non functional allele SO A AND B ARE CO DOMNANT AND O IS RECESSIVE
6
Q
Most common blood types
A
A and O
7
Q
Rarest blood type
A
AB
8
Q
If you have blood group A, what do you have antibodies against?
A
B
9
Q
If you have blood group B, what antibodies do you have against?
A
A
10
Q
If you have blood group O, you have antibodies against……
A
A and B
11
Q
if you have blood group AB, you have NO antibodies against….
A
A and B
12
Q
What blood group is a universal donor?
A
Blood Group O
13
Q
What blood group is a universal recipient?
A
Blood group AB
14
Q
What does FFP contain and not contain compared to blood?
A
DOES NOT Contain the antigen but contains the antibody
15
Q
What is RhD?
A
An antigen which is a transmembrane protein, with ion channels and is hydrophobic
16
Q
How many RhD proteins do people usually have?
A
2
17
Q
Types of RhD blood group system
A
RhD +ve
RhD -ve
18
Q
Who can make anti-RhD and why?
A
RhD negative individuals can make anti-D if exposed to RhD+ cells during
- transfusion
- pregnancy
19
Q
What can anti-D cause?
A
Transfusion reactions
haemolytic disease of the newborn
20
Q
What is tested/looked at in blood donors?
A
Extensive 'behavioural screening' - sex - age - travel - tattoos Tested for ABO and Rh Blood groups Screened for - Hep B/C/E - HIV - Syphilis Variable screened for (if travelled to certain parts of the world) - HTLV1 - Malaria - west nile virus - zika virus
21
Q
What do apheresis donors do?
A
Just take off platelets or just FFP etc
22
Q
Indications for red cell transfusion
A
- to correct severe acute anaemia, which might otherwise cause end organ damage
- to improve QoL in patient with otherwise uncorrectable anaemia
- To prepare a patient for surgery or speed up recovery
- to reverse damage caused by a patients own red cells e.g. sickle cell disease
23
Q
Storage and transfusion of RBCs
A
Stored at 4C (2 - 6 range)
Transfused over 2-4 hours
24
Q
Storage and transfusion of platelets
A
1 dose platelets (=4 pooled or 1 apheresis donor)
stored at approx. 22C
shelf life 7 days
transfuse over 20-30 mins
25
Indications for platelet transfusion
Massive haemorrhage
Bone marrow failure
Prophylaxis for surgery
Cardiopulmonary bypass (only use if bleeding)
26
Components of a platelet transfusion
Fresh frozen plasma
| Cryoprecipitate
27
Storing of FFP
Stored frozen, allowed 30 mins to thaw
28
Indications for FFP transfusion
Massive haemorrhage (1:1 ratio)
DIC with bleeding
Prophylactic
29
Lab tests for FFP
PT and APTT
30
Storing of cryoprecipitate
Stored frozen, allowed 20 mins to thaw
| Cooling FFP at 4C slowly to form the precipitate
31
Lab test of cryoprecipitate
Fibrinogen
32
What does cross match tariff defined by MSBOS mean?
You will have this blood ready ahead of time due to the patient
33
How long are Samples in a blood bank kept for?
7 days
| only valid for 2 days if recent transfusion
34
When is Coombs test positive?
Clumping together of antihuman immunoglobulin to antibodies due to antibody being bivalent
35
Causes of Coombs test positive
```
Direct
- autoimmune haemolytic anaemia
- passive anti-D
- haemolytic transfusion reactions
Indirect
- cross matching
```
36
Blood requirements immediately during a massive haemorrhage
6 units of red cells
4 units FFP (cryoprecipitate?)
1 unit platelets
37
Risks of blood transfusion
Never events (death/harm due to transfusion of ABO incompatible components)
TACO (too much blood too quickly)
ATR
Fever
38
What does TACO stand for?
Transfusion associated circulatory overload
39
What does ATR stand for?
Acute transfusion reaction
40
What is prion disease caused by?
Abnormal prion protein from mad cow disease
41
How to catch prion disease
Transmittable by blood transfusion from earl in disease in sheep
mainly found in older people
another reason not to transfuse blood unless really have to
42
Adverse reactions of a blood transfusion
```
TACO
AHTR
Bacterial infection
TRALI
Pyrexia
urticaria
dyspnoea
Shock
```
43
What does AHTR stand for?
Acute haemolytic transfusion reaction
44
Pathology of haemolytic disease of the newborn
Development of maternal Anti D antibodies (sensitisation)
IgG crosses the placenta
So the mothers RhD negative antibodies go into the placenta and interact with the RH positive blood cells
This causes haemolysis in the foetal circulation
45
Prevention of haemolytic disease of the newborn
Prophylactic Anti-D
- sensitising events
- routine at 28/34
46
Treatment of haemolytic disease of the newborn
```
Careful monitoring
- antibody titres
- doppler US
- IU transfusion
Delivery
Intrauterine transfusion though cannulation of umbilical vein (if cannot deliver baby as too early)
Leucapheresis (bone marrow harvests, donor lymphocyte infusions)
Bone, milk, heart valves, faecal banks
gene therapies
```
47
Pathology of transfusion related acute lung injury (TRALI)
Transfused anti-leucocyte Abs in donor plasma interact with the patients WBCS
Bilateral pulmonary infiltrate
48
Treatment of TRALI
Supportive
| Ventilation
49
What does PTP stand for?
Post transfusion purpura
50
When does PTP occur?
RARE 7-10
| days after transfusion of blood or platelets
51
Pathology of PTP
HPA 1 negative patients form antibodies after transfusion or pregnancy
after further transfusion destruction of own platelets
52
Pathology of transfusion associated graft vs host disease
Rare but always fatal
Graft of lymphocytes in donors blood
- transfused to an immunocompromised host
- homozygosity of donors HLA type
53
How can transfusion associated graft vs host disease be prevented?
Irradiation of blood
54
Is any transfusion risk free?
No
55
What is intraoperative cell salvage?
Gives the patient back their own blood and reduces the risk of needing a transfusion
56
In what ways can a need for blood transfusion be minimised?
Autologous programmes such as intraoperative cell salvage, intra or post operative may be considered
Pre operative care, anaemia correction with iron, stop aspirin/warfarin where possible etc
EPO (recombinant human erythropoietin) can stimulate red cell production in some circumstances
57
How long can blood live outside the body for?
35 days
58
What do neonates < 1 y/o use for blood transfusions?
Peedie pack
59
What does a peedie pack consist of?
Special donors for neonates where 1 donation is split into 5 30ml individual donations
The other 4 will be reserved for the same neonate if one is used so not getting 5 different donations
60
What is the biggest risk of blood transfusion?
Error in administration of blood
61
What is the shelf life for FFP and cryoprecipitate and why is this?
3 years
| As stored frozen
62
What does code red consist of?
Activating major haemorrhage before at the hospital so can have FFP and cryoprecipitate thawed to be ready
63
Once FFP is thawed, how long is it viable for?
4 hours
64
What would happen to platelets If they were put into a fridge?
They would die
65
Who needs irradiation of their blood?
Haematology patients
Some MS patients
Some patients on certain drugs
66
Why do people need their blood irradiated?
Their immune system is so slow they could not handle the T lymphocytes from the donors blood
67
What does blood irradiation prevent?
Transfusion associated Graft vs host disease
68
After a sensitising event / birth of a baby, within what time limit must Anti D be given?
Within 72 hours
69
How long would a T number sticker stay on an ID band for?
However long the sample is viable so should only ever have one at one time
70
What must be checked of the blood unit prior to infusion?
```
No pack leakage
Transfusion port in tact
No evidence of haemolysis
No gas / discolouration / clots
Donation number - pack matches label
Compatibility label against patient's wristband
Blood group - pack compatible with label
Expiry date - not passed
```
71
Current risks of blood transfusion in the UK
```
Hepatitis B
Hepatitis C
HIV/AIDs
vCJD
Hepatitis E
```
72
How much is a unit of blood?
470ml (+/- 50ml)
73
What does a unit of blood consist of?
270 ml of red cell concentrate
| Suspended in plasma plus additive solution
74
What is the donation tested for?
```
HIV
HBV
HCV
HTLVI/II
Syphilis
```
75
In a 70kg recipient, one unit of blood should increase the Hb by how much?
9g/L
76
How must red cells be stored?
4C
| Until < 30 mins before required
77
How is the blood given?
Each unit given over 2-3 hours
| Infusion flow rate of approx. 100mL/hour
78
Indications for red cell transfusion
Perioperative/ITU transfusion
Bone marrow failure
Rarely used to treat iron and other haematinic deficiencies
79
What to tell the patient about red cell transfusion
```
Reason for transfusion
Treatment options
Valid alternatives
Option to refuse
Risks of transfusion
```
80
Management of serious adverse reactions of red cell transfusions
STOP THE TRANSFUSION
keep all residual blood packs
Recheck identity of patient, blood unit and documentation
Check and record patients BP, pulse, RR, and check for dyspnoea, tachypnoea, wheeze, cyanosis
Notify blood bank
Check blood gases or O2 sats
Maintain airway
Seek advise if condition continues to deteroriate
81
Adverse events of transfusion
```
Fluid overload
Acute haemolytic transfusion reaction
Infusion of a bacterially contaminated unit
TRALI
Severe allergic reaction or anaphylaxis
```
82
Where must serious adverse reactions be reported to?
SABRE
83
Under what haemoglobin level is transfusion usually indicated?
70g/L
84
What 3 things to remember about transfusion
Right blood
Right patient
Right time
85
Common allergic reaction symptoms patients may get after having a transfusion
Skin rashes
Fever
Dyspnoea
86
How long does a platelet or plasma transfusion take to give?
Around 30 minutes to an hour
87
Reasons for red cell transfusion
Surgery / accident leading to blood loss
To treat anaemia
Treatment of cancer / leukaemia
88
Reasons for a platelet transfusion
To increase the number of platelets in the blood
| To replace the platelets which are not working properly
89
What does plasma look like when it is going to be transfused? And what does it contain?
Pale yellow liquid
| Red cells, white cells and platelets, also clotting factors
90
What does cryoprecipitate contain?
More than one clotting factor called fibrinogen
91
Once you have had a transfusion, what are you no longer able to do? Why is this?
Donate blood
| Precaution against vCJD transmission
92
What does irradiation do to the blood?
Depleted in T lymphocytes
93
Who is at risk of transfusion assosiated graft vs host disease (TA-GvHD)?
Transfusions from family members / tissue type matched donors
Those born with immune system disorders
Those with a weakened immune system due to Hodgkins disease / treatment with certain drugs / bone marrow or stem cell transplant
Receiving chemotherapy drugs such as fludarabine
Unborn babies and babies needing exchange transfusions
94
Why do plasma products such as FFP, cryoprecipitate, anti D, albumin and immunoglobulin not need irradiated?
They do not cause TA-GvHD
95
What complementary markers tests are done for every donation?
```
Syphillis
HIV
Hep B
Hep C
HTLV 1/2
Hep E
```
96
What is a window period?
The period of which between someone is infected to when it is detectable
97
What do complementary tests now look for in the blood? Why?
Tend to look for antibodies instead of antigens
| Antibodies have a shorter window period than antigens
98
What does vCJD stand for?
Variant CJD
99
What is taken from one donation?
Red cells
Pooled platelets
FFP
Apheresis platelets
100
What are pooled platelets?
Plasma and platelets from 4 donations
101
What are apheresis platelets?
Take out platelets and give the donor back the rest of their blood
102
How are apheresis donors picked?
Donate regularly
Multiple -ve screening tests
ABO and rheus groups
103
What happens if red cells go out of temp range for 30 minutes?
Need to be used or discarded
104
What must be done when storing pooled platelets?
They must be kept constantly moving
105
What is the top layer of cryoprecipitate more concentrated for?
Clotting factors
106
What is FFP more concentrated for?
Fibrinogen
107
What does all of group O have?
H substance
108
How old are you when you start to produce your own blood antibodies?
3 - 4 months
109
How many binding sites does the IgG antibodies have?
2
110
How many binding sites does the IgM antibodies have?
5
111
How are the IgG antibodies destroyed?
Spleen etc
112
How are IgM antibodies destroyed?
Destruction in the veins by cross linking (DIC)
113
What group is the universal plasma donor?
AB
114
What blood group is the go to group for FFP?
A group
115
What blood group is hard to get for FFP?
AB
116
What ways do you get exposure to something foreign to stimulate antibodies?
Pregnancy
| Transfusion
117
What % of the population are Rheusus D +ve and -ve?
```
85% = +ve
15% = -ve
```
118
Why can RhD -ve be transfused to Rh +ve patients?
As no foreign antigen so no antibody stimulated
119
What blood group can be transfused to all patients no matter what blood group they are?
O RhD negative
120
What does a second sample blood policy reduce?
Wrong blood in tube incidents
121
Who is the second sample blood policy for?
Non urgent requests
1st time blood component request
> 12 months old
122
How long should there ideally be between the two blood samples?
10 minutes
123
How does the second sample policy not refer to?
Urgent
Infants up to 12 months
Patients whose blood groups are already known to the lab
124
The 8 main blood groups
```
A +
A -
B +
B -
AB +
AB -
O +
O -
```
125
Give examples of who would be given irridated blood
Granulocyte transfusions
IU transfusions
Neonates up to 28 days post expected date of delivery
Bone marrow / stem cell transplants
Immunocompromised (e.g. chemo or congenital)
Patients with / previous Hodgkins disease
126
Hb transfusion threshold
Without ACS - 70 g/L
| With ACS - 80g/L
127
In patients who are not currently bleeding or about to undergo a procedure, a platelet transfusion should be performed if the plaelets fall to below what level?
10 x10^9/L
128
What conditions would a platelet transfusion have an increased risk of death?
Thrombotic thrombocytopenic purpura
Heparin induced thrombocytopenia
Autoimmune thrombocytopenia
Chronic bone marrow failure
129
What platelet count should a platelet transfusion be offered to a patient if they are actively significantly bleeding?
< 30 x10^9
130
What do platelets have an increased risk of compared to other types of blood product?
Bacterial contamination
131
What is the universal donor of FFP?
AB RhD negative
132
What is used to reverse the effects of anticoagulation in an emergency when the patient has a head injury or severe bleeding?
Vitamin K AND
| Prothrombin complex concentrate
133
Treatment of acute haemolytic transfusion reaction
Generous fluid resuscitation (saline)
| Termination of the transfusion
134
Treatment of post transfusion purpura
High dose immunoglobulin therapy
135
Treatment of allergic transfusion reaction
IM adrenaline, corticosteroids and supportive care
| Bronchodilators
136
What causes acute haemolytic transfusion reaction?
Mismatch of blood group (ABO) which causes massive intravascular haemolysis
Usually the result of RBC destruction by IgM-type antibodies
137
Presentation of acute haemolytic transfusion reaction
```
Symptoms begin minutes after transfusion
Fever
Abdominal pain
Chest pain
Agitation
Hypotension
```
138
Complications of acute haemolytic transfusion reaction
DIC
| Renal failure
139
Pathology of non haemolytic febrile reaction
Due to white blood cell HLA Abs
| Often the result of previous sensitisations by pregnancies or transfusions
140
Treatment of non haemolytic febrile reaction
Paracetamol
141
Pathology of anaphylaxis / allergic reaction post transfusion
Hypersensitivity to components within the transfusion
142
Presentation of allergic reaction / anaphylaxis post transfusion
Within mins of starting
Severity can range
- urticaria to anaphylaxis with hypotension, SOB, wheezing, stridor or angioedema
143
Features of TRALI
```
Development of hypoxaemia / ARDS within 6 hours of the transfusion
Hypoxia
Pulmonary infiltrates on X ray
Fever
Hypotension
```
144
Presentation of TACO
Pulmonary oedema
| HTN
145
When can IV iron be used?
Patients with iron deficiency anaemia prior to surgery when oral iron cannot be tolerated or the time interval is too short
146
What is the major criteria to determine if the use of cryoprecipitate is needed in bleeding?
Low fibrinogen level
147
What is the major constituent of cryoprecipitate?
Factor VIII
