Blood Transfusions Flashcards
What are some of the common indications for red cell transfusions?
Symptomatic anaemia Hb <70g/l Major haemorrhage Acute sickle cell crisis Acute coronary syndromes
What are the risks associated with red cell transfusions?
Transmission of infection
TACO
Transfusion reaction
ABO incompatibility
Tell me about infection transmission due to blood transfusion.
Very uncommon.
Hep B risk is 1 in 800,000. Most common infection transmitted.
HIV risk is less than 1 in 1,000,000
What is TACO?
Transfusion associated circulatory overload
Why does TACO occur?
Increased blood volume due to transfusion
When a pt has group and save done, what do we mean?
Blood samples are taken to check for the pts ABO and rhesus D group to find blood products that are compatible with the pt.
No blood is issued.
How many times must a pt have been group and saved before blood product can be given?
Twice (1 can be historical) at 2 different times
What are Rhesus grouping?
Looking for red blood cell surface antigens of the rhesus type
What % of the population is RhD+?
85%
When is RhD status very important to know? Why?
With women who intend to have children.
If mother is RhD- but foetus is RhD+, she will develop RhD antibodies.
If in a later pregnancy, she has another RhD+ feotus, her antibodies will bind to the foetus’ RhD antigens via the placenta, so the foetal immune system attacks itself.
What term is used to describe when the foetal immune system attacks itself due to rhesus incompatibility?
Haemolytic disease of the newborn (destruction of foetal RBCs -> foetal anaemia)
Why is it important to “stick to the script” when prescribing blood products?
Because despite all the rules, a lot of errors still occur causing adverse events, so follow the rules to minimise error.
When requesting blood products, what do you need to do and then check?
- Use the 3 points of identification.
- Consent the patient appropriately.
- Label the bottles and complete the request at the bedside, so the pt can check the details.
- Use the 3 points of identification.
What are the 2 special types of blood product?
- CMV negative blood products
- Irradiated blood products
Who do we give CMV negative blood products to?
- Women during pregnancy
- For intra-uterine transfusions
- Neonates up to 28 days
Why do pregnant women need CMV negative blood?
CMV is highly teratogenic
If a pregnant woman needs blood products, what do we need to do?
Tell the lab she is pregnant!!!
What is the point of irradiated blood?
It prevents transfusional graft vs host disease
Who needs irradiated blood?
- Pts who are immunosuppressed (allogenic stem cell transplant pts, very suppressed T cell count)
- Pts on purine analogue chemotherapy
- Pts on Lentrada as Rx for MS
- Any pt who has ever been diagnosed with Hodgkins lymphoma
What are the purine analogues that mean a pt needs irradiated blood?
Fludarabine
Cladribine
Deoxycoformicin
When should obs be done on a pt receiving blood products?
Before the transfusion starts, 15 minutes into transfusion, at 1 hour, and at completion.
What size cannula do blood products need to go through and why?
Green 18G or grey 16G to prevent sheering forces
After a single unit of red blood cells is given, what should we do?
Clinically reassess the pt and check Hb levels before proceeding with any further transfusions i.e. check they’re still needed
If a pt is having surgery or an invasive procedure, what level of platelets does the pt need to have?
50x10^9 per litre or above
How many platelet transfusions can you give to a pt?
No more than one single dose routinely (special circumstances may apply)
What are the signs and symptoms of transfusion reaction?
Pt feels unwell, feverish, has pain along transfuion site, feeling of impending doom, loin pain.
Signs of shock, fever.
What do we do if transfusion reaction is suspected?
- Stop transfusion
- ABCDE assessment and act accordingly
- Escalate
- Let ITU know
- Check blood bag details against pt
What blood tests can help show if transfusion reaction has happened?
- FBC
- U and Es (renal failure)
- LFTs (intravascular haemolysis)
- LDH
- K+ may be an issue
- Haptoglobin (very low if rxn occurs)
Aside from blood analysis, what else should we do to investigate transfusion reactions?
- Send blood back to lab for testing
- Repeat group and save
- Urine sample for haemosidarin
Which blood product has the highest chance of transmitting infection, and why?
Platelets because they are stored at room temperature
If there is bacteria in the blood product, where could it have come from?
- Undiagnosed/asymptomatic bacteraemia in the donor
- Contamination on collection of blood product
Talk me through collecting a blood sample for a blood transfusion.
- Confirm Pt ID to their hospital bracelet.
- Consent for blood transfusion where necessary.
- Collect sample in pink top bottle.
- Add details to bottle at the bedside from ID wristband.
- Sign bottle
- Complete blood transfusion form
- Send off to lab
What do we have to fill out on the blood transfusion form?
- All pt details including ward and NHS number
- Any special requirements
- Number of units needed if crossmatching
- Signature and date
How many units of blood can you prescribe in one go?
One unit only!
How long do we transfuse red blood cells over?
2-3 hours per unit in non-urgent situation
What is the only exception to the following rule:
Blood can only be transfused into a patient after the 3 points of ID are matched exactly from the pt wristband to the blood bag.
If it is an emergency situation where O negative blood has been given.
The bag will say something like “Flying Squad” on it.
When should blood products be given?
Within half an hour of leaving the refrigerator.
What do we do before starting a transfusion?
- Ask a nurse/doctor to check with you
- Match the pt ID bracelet, blood bag, and notes exactly.
- Check the right bag of blood has been sent (compatibility report)
- Check blood bag expiry date
- Inspect the bag
When we inspect the bag, what do we look for?
- Signs of tampering
- Leaks
- Discolouration
- Clots
- “Goldfish” - bits of still frozen product.
What is special about a blood giving set?
The chamber has a filter within it.
If a reaction occurs within 24 hours of starting the transfusion, which immune reactions could have caused this?
- ABO incompatibility
- TRALI
- Anaphylaxis
If a reaction occurs within 24 hours of starting the transfusion, which non-immune reactions could have caused this?
- Bacterial Infection
- TACO
If a reaction occurs after 24 hours of starting the transfusion (delayed), which immune reactions could have caused this?
- Delayed haemolytic transfusion rxn
- Febrile non-haemolytic transfusion rxn
- Post-transfusion purpura
- Graft vs Host disease
If a reaction occurs after 24 hours of starting the transfusion (delayed), which non-immune reactions could have caused this?
- Viral infection
- Malaria infection
- Prion infection
What are the 4 main steps in doing a blood transfusion?
Collect a sample
Prescribe/request the blood
Check the blood transfusion
Monitor the patient
When inspecting a blood bag, what do we look for to check the product is ok?
Any signs of tampering, leaks, discolouration, or clotting.
Talk me through the process of administering the blood.
Check the pt has a 16 or 18G cannula in (green or grey) - if not, put one in.
Attach the blood bag to the blood giving set and run some blood through to expel the air.
Once air expelled, attach the other end of the giving set to the cannula.
Set the drip rate (2-3 hours for one unit if not urgent).
Document time and date transfusion started with a colleague and sign to confirm all checks were carried out.
