Blood Transfusion Flashcards
What Antigens will group A blood type patients have on their RBCs? and what antibodies in their plasma?
On RBC = A Antigens
In Plasma = Anti B antibodies
What antibodies will group B blood type patients have on their RBCs? and what antibodies in their plasma?
On RBC = B antigens
In Plasma = Anti-A antibodies
What antibodies will group AB blood type patients have on their RBCs? and what antibodies in their plasma?
On RBC = A and B antigens
In Plasma = No antibodies
What antibodies will group O blood type patients have on their RBCs? and what antibodies in their plasma?
On RBC = No antigens
In Plasma = Anti A and Anti B Antibodies
Why can AB+ take blood from anyone?
AB people do not have any antibodies in their plasma, so there is nothing to attack the foreign RBCs when they are transfused
How do you cross match a sample of blood for transfusion?
Take a sample of PATIENTS SERUM (as serum contains the antibodies) and the DONOR RBC - if they agglutinate (clump) then the samples are incompatible
During blood testing, what infections are tested for?
HIV, HEP B C E, HTLV And Syphillis
Do we test for Creutzfeldt-Jacob Disease?
Yes
Who do we give red cells to?
Patients with anaemia
Who do we give Fresh Frozen Plasma to?
People who are bleeding and their clotting is deranged, or reverse warfarin quickly eg if they are about to have surgery
What does cryoprecipitate have specifically?
Fibrinogen and Vin Willebrand Factor
When is cryoprecipitate given?
If massive bleeding or fibrinogen is very los
Who do we give factor 8 and 9 to?
Hemophiliacs = factor 8 and 9 deficiency
In what circumstance might we give a patient immunoglobulins?
Hepatitis A sufferers
What RhD group are you if you lack the RhD antigen?
Negative
Do RhD negative patients have Anti-D antibodies in their plasma?
No but they can make Anti - D antibodies
How do RhD Negative People make anti D antibodies?
- Women may be pregnant with a RhD positive baby
2. Transfusion of RhD positive blood
If a RhD negative patient has a blood transfusion with a RhD positive person, what implications does this have for their future transfusion?
Their next transfusion must be with an RhD negative individual otherwise the Anti-D antibodies which they will have made will react with the D antigens on the RBC of RhD positive people and cause a haemolytic transfusion reaction - in this case delayed as it occurs during the second transfusion. can also cause jaundice and high bilirubin due to haemolysis
What is haemolytic disease of the newborn?
This is where an RhD negative first child was RhD positive so mother made Anti-D antibodies, and second child is also RhD positive, then the Anti-D antibodies can cross the placenta and cause haemolysis of the foetal red cells
What allows the Anti-D antibodies to cross the placenta?
They are class IgG
What implications does Haemolytic Disease of the Newborn have?
If severe, baby does not survive birth
If leas severe, baby may survive birth but brain may be damaged due to high build up of bilirubin in the brain, leading to death
How can the formation of Anti-D antibodies in mothers be prevented?
Give them Anti-D Immunoglobins
How does giving the mother Anti-D immunoglobins work to prevent HDN?
Anti-D works by destroying any RhD positive blood in the mother’s circulation, before it can be recognized by the mothers systems and therefore before the mothers own Anti-D antibodies can be made, thus preventing HDN
Which blood component will patients need to replace all their clotting factors which have been depleted during massive bleeding?
Fresh frozen plasma
In an emergency which group of Fresh Frozen Plasma should we give when we do not know their blood group?
AB negative and positive as the plasma will not contain any antibodies
In an emergency, which group of red cells can we give to any patients?
O Negative Blood - this is because O negative Red Cells do not have A or B antigens on the surface of the Red cells which could be attacked by the patients Anti-A Antibodies or Anti-B Antibodies
What gene controls blood group?
The ABO gene
What is added to the the common H antigen to make it an A Antigen?
N-Acetyl galactosamine
What is added to the the common H antigen to make it an B Antigen?
Galactose
Which carbohydrate stem does group O have?
Only the H stem
Which group is recessive?
O
Which RhD group can be given to both positive and negative?
Negative
Which blood groups can RhD positive blood be given to?
Only positive
What is group and screen?
Find out the ABO and RhD group, and then screen for any other weird antibodies - then perform cross match to see if agglutination occurs
Every donation is tested for what?
Infections, viruses eg HIV, Amy other clinically significant red cell antibodies
What is apheresis?
Separates the blood into its individual components
What is one unit of blood?
The whole blood or blood products derived from one single blood donation
What is the shelf life of RED CELLS
35 days
What is the shelf life of FFP?
3 years
In a non-emergency, which group of FFP is given to A blood group people?
A group - donor same FFP as patient
What blood component should be given when there is a abnormal PT and aPTT?
FFP, to replace all clotting factors
What is cryoprecipitate?
Cryo is FFP that has been repeatedly thawed, to produce a high concentration of certain clotting factors including fibrinogen, VwF and factor 8
Why does Cryo not contain all the clotting factors?
Most degenerate at room temperature, therefore since cryo has been thawed it does not have such factors
Why is factor 8 and 9 heat treated for haemophilia treatment?
To inactivate viruses that may be present
Why might patients be given platelets?
Thrombocytopenia
What two forms are platelets available in?
Pooled platelets or from a single donor
What class of antibodies are the ones found in plasma?
IgM
What condition can IgM antibodies cause?
Massive Intravascular Haemolysis
Due to risk of viral transmission, what are Haemophilia patients now treated with?
Recombinant factor 8 and 9
What are the four stages of pre-transfusion testing that needs to be done?
ABO group
RhD group
Alloantibody screen
Cross matching
