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.
