Blood Transfusion - Basics Flashcards
What is SHOT?
Serious Hazard of Transfusion
How long can you keep red blood cells for?
35 days
What happens to the potassium level in RBC components over time?
Increases
Why would you prefer to give neonates fresh blood?
Less of a potassium load than older blood, which is better for neonates
What can cause a “wrong blood in tube” scenario?
- Sample from wrong patient
- Unit collection errors
- Failure of final bedside checking
- Failure to request “special requirement” i.e. irradiated blood
What temperature are platelets kept at?
Room temperature
Why do BTS only take FFP from male donors?
Due to females developing unusual antibodies during pregnancy
What is the purpose of having 2 samples for crossmatch?
To make you go through the process of checking blood samples twice
How long are crossmatch tubes valid for?
3 days
Why is group O the universal red cell donor?
Lacks both A and B antigens, therefore doesn’t react with anti-A or anti-B antibodies in group A, group B and group AB plasma
What percentage of samples are rejected?
5%
When checking blood units prior to transfusion, what do you need to check?
- No pack leakage
- Transfusion port intact
- No evidence of haemolysis
- No gas/Discolouration/Clots
- Donation number - pack matches label
- Blood group - Pack compatible withlabel
- Expiry date
When checking Patient against transfusion sample, what do you want to check?
IF ANY DISCREPANCY, do not transfuse
- Name
- DOB
- T number
- CHI/Hosp. Number
IF interrupted, stop and start again. Do not leave the patient until transfusion commenced
When labelling a sample for transfusion, what do you need to do?
Print patient details on the tube
- Name
- DOB
- CHI/Hosp. Number
- Ward
- Gender
- Date and time of sample
Apply T number labels to tube and wrist band if NHS highland
What are the main blood components?
- Red Cells
- Platelets
- FFP
- Cryoprecipitate
What temperature are red cells stored at?
4oC
What temperature are platelets stored at?
22oC
What temperature is FFP stored at?
-25oC
What is the universal red cell donor group?
Group O RhD negative
What is the universal FFP donor group?
Group AB RhD positive
Why is group AB the universal plasma donor?
AB people have no antibodies IN THEIR PLASMA as they have both A and B antigens on their red cells, therefore no antibodies are produced against them.
This is the same reasoning for the plasma being RhD positive
What antibodies will group A blood groups have?
Anti-B antibodies
How long can you store RBCs for?
36 days
How long can you keep Platelets?
5 days
How long can you keep FFP?
36 months
What moelcule makes up the A antigen?
N-acetyl-galactosamine

What molecule makes up the B-antigen?
D-galactose

Why do individuals produce antibodies against antigens not on their RBC?
Thought to be due to exposure to viral/bacterial/plant lectins in food which resemble these antigens, which they react against.
If someone had group A blood, what donor RBCs can be used?
- Group O
- Group A
If someone was group O, what donor RBCs can be used?
Group O only
If someone is group B, what donor RBCs can be used?
- Group O
- Group B
If someone has group AB blood, what RBC donor can be used?
- Group O
- Group A
- Group B
- Group AB
If someone had group A blood, what donor FFP can be used?
- Group AB
- Group A
If someone was group O, what donor FFP can be used?
- Group O
- Group A
- Group B
- Group AB
If someone is group B, what donor FFP can be used?
- Group AB
- Group B
If someone has group AB blood, what FFP donor can be used?
- Group AB
Why can you give RhD negative blood to an RhD positive person?
There is no foreign antigen on RhD blood, therefore no antibody will be stimulated
Why can’t you give RhD positive to RhD negative individual?
Foreign antigen present on cells, therefore antibodies will be produced by RhD negative individual
Can you give RhD negative to RhD positive individual?
Yes
Can you give RhD positive to an RhD negative individual?
No
What tests are done in crossmatching?
- ABO grouping
- RhD grouping
- Antibody screening
- Antibody ID
- Select and label compatible components
What blood group is the universal reciever for RBCs?
Group AB
What blood group is the universal reciever for FFP?
Group O
What does the second sample pre-transfusion requirement apply to?
Non-urgent, first time blood component requests
What does the second sample pre-transfusion requirement not apply to?
- Urgent blood requests
- Requests for infants up to 12 months of age
- Requests for patients whose blood group is already known to the lab
What is important to remeber about the second sample pre-transfusion requirement?
Take each sample at different time points
If blood was urgently required, what blood is available?
Major haemorrhage protocol
- 6 units red cells
- 4 units FFP (cryoprecipitate?)
- 1 unit platelets
If you required urgent crossmatch, how many samples would you need to send to the lab?
1 sample
If you required urgent transfusion, how quickly can samples sent to the lab be turned around?
25-30 minutes
What testing is done on a sample sent to the labs for urgent transfusion?
- ABO and RhD
- Antibodies are not tested - screen done retrospectively
If you requested an elective transfusion from the labs and the patient was already known to the laboratory, how amny samples would you need to send?
1 sample
If you required elective transfusion for a new patient, how many samples would you send to the lab?
2 samples
How quickly should you transfuse RBCs?
Over 2-4 hrs
How quickly should you transfuse platelets?
20-60 minutes
Are bloods issued for a group and save sample?
No - only makes patient aware to the lab so if needed in the future only need one sample
What volume is the minimum volume for a crossmatch/group and save sample for it not to be rejected?
2 ml
If someone has post-op fluid resuscitation, what happens to the haematocrit?
Decreases - artficially diluted by resus fluids
What proportion total blood volume (approx 5L) of blood is red cells?
40% - Hct 4.0
What should you never do with regard to treating somone based on haemoglobin results?
Treat solely based on these results - need to look at:
- Hct
- Normal Hb based on age sex and size
- Rate of loss
- Ongoing loss
- Risk of symptoms
- Ability to compensate
- Observable signs
If someone was losing blood from a perforated gastroduodenal artery, and another person is losing blood from the brachial artery, which person is likely to require transfusion?
Individual with gastroduodenal ulcer - brachial artery can be stopped relatively easily compared to ulcer, therefore ulcer will have relatively more loss and will be more likely to require transfusion
When would you consider asking a patient for autologous blood?
Those with a lot of antibody’s for whom matching will be very difficult- e.g. multipregnancy
What is intra-operative cell salvage?
A medical procedure involving recovering blood lost during surgery and re-infusing it into the patient. It is a major form of autotransfusion

What are contraindications to IOCS?
- Cancer
- Abdominal surgery - risk of infection
- Debris

When would you consider tranfusing someone who was anaemic?
When they became symptomatic
How would you determine how many units of blood to give someone?
Based on clinical signs/symptoms - give single units and assess whether sympatomatic. If remains symptomatic, give another single unit and reassess
How long after blood has been removed from the fridge do you have to transfuse blood?
4 hours maximum after removal from refrigeration** to the **END of transfusion.
This is to reduce the risk of septic reactions due to bacteria proliferting in blood once it has warmed