Blood transfusion and blood products Flashcards
what are the 4 components of blood?
- RBC
- platelts
- white cells
- plasma
what is plasma
Plasma is the liquid portion of blood, making up approximately 55-60% of blood by volume. It tends to be clear to straw yellow in colour.
Plasma is mostly water, but also contains:6
Amino acids
Electrolytes
Gases
Nitrogenous waste
Nutrients: including glucose and fat particles
Proteins: including albumin, globulins, enzymes, clotting factors like fibrinogen, and hormones
what are the 4 main blood products
- packed red cells
- fresh frozen plasma
- platelts
- cryoprecipitate
what are packed red cells used for?
These are used to restore oxygen carrying capacity in patients with anaemia or blood loss where alternative treatments are ineffective or inappropriate. They must be ABO compatible with the recipient
what needs to be checked before giving packed red cells?
ABO compatibility
By how much does 1 unit of packed red cells raise Hb
In adults, one unit brings up hemoglobin levels by about 10 g/L (1 g/dL).
what is fresh frozen plasma used for? dose?
FFP is indicated for the treatment of patients with bleeding due to multiple clotting factor deficiencies such as disseminated intravascular coagulation (DIC). It may also be used in patients with inherited clotting factor deficiencies (e.g. Factor V deficiency) where a clotting factor concentrate is not yet available.
The recommended dose is 12–15 mL/kg (minimum of four units in a 70 kg adult) However, much larger doses may be needed to produce ‘therapeutic’ levels of coagulation factors and volume overload is a significant clinical problem
what is cryoprecipirate ? when is it used?
Cryoprecipitate (cryo) contains a concentrated subset of FFP components including fibrinogen, factor VIII coagulant, vonWillebrand factor, and factor XIII.
Cryoprecipitate is used for hypofibrinogenemia, vonWillebrand disease, and in situations calling for a “fibrin glue.” Cryo IS NOT just a concentrate of FFP. In fact, a unit of cryo contains only 40-50% of the coag factors found in a unit of FFP, but those factors are more concentrated in the cryo (less volume).
when are platelets used?
Platelet transfusion is indicated for the treatment or prevention of bleeding in patients with a low platelet count (thrombocytopenia) or platelet dysfunction.
definiton of major haemorrhage?
Major haemorrhage =
Loss of more than one blood volume within 24 hours
50% of total blood volume lost in less than 3 hours
Bleeding in excess of 150 mL/minute
However, in an acute scenario, you are unlikely to be able to calculate blood loss as above. Therefore, a major haemorrhage can be considered as bleeding (visible or presumed) which results in:2
A blood pressure <90mmHg systolic
A heart rate >110bpm
PC: trauma patient, pale, clammy and hypotensive, tachycardic
who should get blood transfusion pre-op?
- If Hb is less than 90g/L and the surgery is associated with the probability of significant blood loss. HOWEVER Pre-operative anaemia must be investigated, as medical management may be more appropriate than transfusion, particularly if the patient is asymptomatic.
Seek to maintain Hb above 70g/L with a target range of 70-90g/L post transfusion (consideration of above 80g/L in patients with significant comorbidity e.g. age over 70 years with co-morbidity, ischaemic heart disease, valvular heart disease and peripheral vascular disease aiming for a target range of 80 - 100g/L). Always reassess indications for any further transfusions after each unit is administered.
when is blood transfusion indicated in acute MI
Hb <80g/L – Transfusion to an Hb of 80 - 100g/L is desirable. Evaluate effect of each unit as it is given. In patients who may have impaired cardiac function, be particularly aware of the risk of Transfusion associated Circulatory Overload (TACO). Investigation of the cause of anaemia is required.
what Hb is an indication for transfusion?
Hb <70g/L – Consider transfusion but evaluate after each unit.
Hb 70– 90g/L and normovolaemic patients – Consider transfusion only if they have symptomatic anaemia or significant comorbidity.
over how long should a blood transfusion be given?
In non-urgent scenarios, a unit of blood is typically transfused over a 2-3 hour period.
in urgent - asap
monitoring for blood transfusion
- The patient’s baseline observations should be checked at 0, 15 and 30 minutes from the onset of the transfusion.
- Observations can then be performed on an hourly basis and again when the transfusion has finished.
Regular observations allow early detection of transfusion reactions.
which transfusion reaction? management? pathophysiology?
fever and chills
non-haemolytic febrile reaction
management:
- stop or slow the infusion, paracetamol, monitor
antibodies reacting with white cell fragments in the blod product and cytokines that have leaked from blood cell during storage
which transfusion reaction? management? pathophysiology?
pruritis, urticaria
minor allergic reaction
manageemnt
1. temporarily stop the transfusion, antihistamine, monitor
thought to be caused by foreign plasma proteins
which transfusion reaction? management? pathophysiology?
hypotension, dyspnoea, wheezing, angiodema
anaphylaxis
- stop transfusion
IM adrenaline
ABC support
- O2
- fluids
can be caued by patients with IgA defieicny who have anti-IgA antibodies
which transfusion reaction? management? pathophysiology?
fever, abdominal pain, hypotension
acute haeemolytic reaction
- stop transfusion
confirm diagnosis
- check the identity of patient/name on blood product
- send blood for direct coombs test, repeat typing and cross amtcging
supportive care
fluid resus
ABO incompatible blood eg secondary to human error
which transfusion reaction? management? pathophysiology?
pulmonary oedema, hypertension
Transfusion-assocaited circualtory overload
- slow or stop tranfusion
consider IV loop diuretic and oxygen
excessive rate of transfusion, pre-existing heart failure
which transfusion reaction? management? pathophysiology?
hypoxia, pulmonary infiltrates on CXR, fever, hypotension
Transfusion-related acute lung injury (TRALI)
Stop the transfusion
Oxygen and supportive care
Non-cardiogenic pulmonary oedema thought to be secondary to increased vascular permeability caused by host neutrophils that become activated by substances in donated blood
antibodies to human neutrophil antigens and human leukocyte antigens have been implicated.
which delayed transfusion reaction?
3 to 14 days after the transfusion
sudden drop in haemoglobin level, fever, jaundice and haemoglobinuria
Delayed haemolytic transfusion reaction (DHTR)
Delayed haemolytic reactions are caused by antibodies to antigens such as Rhesus or Kidd.
which delayed transfusion reaction?
5-12 days after transfusion
purpura, thrombocytopenia
Post-transfusion purpura (PTP)
PTP is an adverse reaction to a blood transfusion or platelet transfusion that occurs when the body produces alloantibodies to the introduced platelets’ antigens.
These alloantibodies destroy the patient’s platelets leading to thrombocytopenia.
what is graft vs host disease
Graft versus host disease is a medical complication following the receipt of transplanted tissue from a genetically different individual.
Immune cells (white blood cells) in the donated tissue (the graft) recognize the recipient (the host) as foreign (nonself). The transplanted immune cells then attack the host’s cells.
GvHD can occur after a blood transfusion if the blood products used have not been irradiated or treated with an approved pathogen reduction system.
key difference TACO and TRALI
TACO - hypertensive
TRALI - hypotensive
What is prothrombin complex concentrate? When is it used
Prothrombin complex concentrate (PCC) is the preferred treatment option to rapidly reverse the anticoagulant effect of warfarin in patients with life-threatening bleeding, such as an intracranial haemorrhage. PCC contains factors II, VII, IX and X, which are essential for normal blood clotting. In addition to vitamin K, PCC will help to quickly normalize the patient’s INR and reduce the risk of further bleeding.
What blood product have the highest risk of bacterial contamination
Platelet transfusions have the highest risk of bacterial contamination compared to other types of blood products
At what platelet level should you give platelets in active bleeding
Offer platelet transfusions to patients with a platelet count of <30 x 10 9 with clinically significant bleeding (World Health organisation bleeding grade 2- e.g. haematemesis, melaena, prolonged epistaxis)
Platelet thresholds for transfusion are higher (maximum < 100 x 10 9) for patients with severe bleeding (World Health organisation bleeding grades 3&4), or bleeding at critical sites, such as the CNS.
It should be noted that platelet transfusions have the highest risk of bacterial contamination compared to other types of blood product.
At what platelet level should you give patients platelets pre-invasive procedure
Platelet transfusion for thrombocytopenia before surgery/ an invasive procedure.
Aim for plt levels of:
> 50×109/L for most patients
50-75×109/L if high risk of bleeding
>100×109/L if surgery at critical site
At what platelet level should you give patients platelets if no active bleeding and no planned invasive procedure
A threshold of 10 x 109 except where platelet transfusion is contradindicated or there are alternative treatments for their condition
For example, do not perform platelet transfusion for any of the following conditions:
Chronic bone marrow failure
Autoimmune thrombocytopenia
Heparin-induced thrombocytopenia, or
Thrombotic thrombocytopenic purpura.
When are irradiated blood products used?
Irradiated blood products are used to avoid transfusion-associated graft versus host disease
How much FFP in major haemorrhage
4 bags usually. 3 bags of small adult
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