Blood transfusion Flashcards
State benefits of blood transfusion
- Relieve symptoms of anaemia (consider nutritional causes)
- Improve delivery of oxygen to tissues
- Replace blood loss
- Help prevent further blood loss
- May be needed for medical procedure
State some risks of blood transfusion
Blood transfusions in the UK are usually very safe
However risks are:
- Acute haemolytic transfusion reactions OR delayed transfusion reaction
- Blood borne infections e.g. Hepatitis B
- Receiving unsuitable blood
- Fluid overload (TACO)
- Lung injury (TRALI)
- Iron overload (if repeated transfusions)
- Rare theoretical risk of CJD (Creutzfeldt-Jakob disease)
*In pregnant women, complications if given rhesus positive blood
Once received a blood transfusion - can no longer donate blood
State the different types of blood transfusion reaction
- Acute haemolytic reaction (immune-mediated intravascular or extravascular haemolysis from incorrect blood given)
- Delayed haemolytic reaction
- Simple allergic reaction = hypersensitivity to a foreign protein
- Anaphylactic reaction = can occur in a patient with IgA deficiency
- TRALI (transfusion-related acute lung injury) = release of mediators leading to pulmonary oedema
- TACO (transfusion-associated circulatory overload) = fluid overload
- Sepsis = bacteria or bacterial byproducts
- Transfusion-associated graft-versus-host disease
State some common symptoms of a transfusion reaction
- Urticaria / itching
- Respiratory distress / dyspnoea
- Hypotension
- Fever / chills
State what is meant by a group and screen (G&S) and cross matching
Group and screen (G&S):
- Tests patient’s blood group (ABO and RhD)
Cross matching:
- Physically mixing the patient’s serum with the donor RBCs, in order to see if any immune reaction occurs
State the meaning of electronic issue in blood transfusion
Allows blood to be issued after a group and screen (G&S), without the need for a physical cross-matching test to take place
Can only be used in the following circumstance:
- Never been pregnant in last 3 months
- No previous blood transfusions in last 3 months
Outline what is an allo-antibody and why they are significant in blood transfusions and haemolytic disease of the newborn
Allo-antibodies are antibodies which are produced in response to exposure to incompatible blood groups antigens
Typically as a result of either
1) Blood transfusion
2) Pregnancy
State some alternatives to blood transfusion
- Iron replacement therapy (oral or IV)
- Cell salvage if surgery (autologous blood transfusion)
- EPO injections
- Doing nothing
Prophylactic methods to reduce blood loss (reduce risk of needing blood transfusion in first place)
- Iron supplementation (correct anaemia)
- Tranexamic acid (reduce blood loss during surgery)
How long can blood last after being removed from storage
4 hours
State the main reason for transfusing red cells and state 3 main indications for red cell transfusion
Improve oxygenation to the tissues by increasing the circulating red cell mass
The main indications include:
1. Acute blood loss (acute blood loss 30-40% of circulating volume)
2. Anaemia (haemoglobin < 70g/L)
3. Haemoglobin disorders
Give 1 unit at a time
State some ways to mitigate the risk of TACO (transfusion associated circulatory overload) in vulnerable patients
- Prescribe one unit at a time and consider prescribing according to body weight
- Transfuse at a slower rate
- Consider use of a prophylactic diuretic
- Monitor the observations closely, including oxygen saturations
- Measure fluid balance
.
Review the patient following each unit = recheck Hb level
How much should 1 unit of packed red cells increase haemoglobin by?
10 g/L
How much should 1 unit of platelets increase platelets by?
20 x 10(9)/L
What is the normal platelet range?
Between 150 and 400 x 10(9)/L
State the main reason for transfusing platelets and state 3 main indications for platelet transfusion
Mostly, platelets are given to prevent rather than to treat bleeding when platelet count is low
Given when platelets < 10 x 10(9)/L
Also given when platelets between 10 - 20 x 10(9)/L, if there are additional risk factors for bleeding
Prophylactic platelet transfusion:
1. Prevent bleeding prior to an invasive procedure
2. Treat acute/major bleeds
3. Reversible bone marrow failure
State the 2 transfusion fluids which help to replace coagulation factors (bleeding) and for plasma exchange
- Fresh frozen plasma (FFP)
- Cryoprecipitate
Briefly outline how fresh frozen plasma (FFP) is prepared and which blood type should it come from
- White cells are removed
- Prepared from anti-coagulated, whole blood
- Rapidly frozen (maintain activity of labile coagulation factors)
FFP from a donor of an identical ABO Group should be used as the first choice
A patient’s rhesus antigen status is not relevant for FFP
State some indications for fresh frozen plasma (FFP)
- Major haemorrhage
- Acute DIC (actively bleeding)
- Inherited coagulation factor deficiency
- Prolonged PT/INR (bleeding or prior to procedure)
Give 12-15ml/kg (usually 3-4 bags per adult)
Prophylaxis before surgery / invasive procedure if abnormal coagulation test results AND additional risk factors for bleeding
Briefly outline how cryoprecipitate is prepared, which components it is rich in
Cryoprecipitate is produced by slowly thawing a single donation of fresh frozen plasma at 4-6°C
This brings out the following components:
- Factor VIII (8)
- Factor XIII (13)
- Von Willebrand factor
- Fibrinogen
- Fibronectin
These factors are resuspended in a small volume of plasma
State the main reason for transfusing cryoprecipitate and state the main indications for cryoprecipitate transfusion
Cryoprecipitate is almost exclusively used to enhance fibrinogen level
Conditions with low fibrinogen!
- Prophylaxis before surgery / invasive procedure (fibrinogen < 1 g/l)
- DIC with bleeding (fibrinogen < 1 g/l)
- Major haemorrhage (fibrinogen < 1.5 g/l)
- Major obstetric haemorrhage (fibrinogen < 2 g/l)
Give approximately 2 pools