Transfusion Flashcards
State the criteria for blood donation
Hb 135g/l in males
Hb 125g/l in females
Weight >50kg
Describe the storage of each type of cell
Red cells - 4 degrees for 35 days
Platelets - room temp for 7 days with agitation
Plasma - - 30 degrees for 3 years
What microbiology tests are carried out on donor blood?
HIV, HBV, HCV, HEV, HTLV, Syphillis
What blood components are available for transfusion?
Red cells
FFP
Platelets
Cryoprecipitate
What blood products are available for transfusion?
Anti-D immunoglobulin Prothrombin IV immunoglobulin Human albumin Specific Ig - zoster
What chromosome is the ABO gene on?
9
What do A and B genes do?
Code for transferases which modify precursor H substance on the red cell membrane
For each ABO phenotype give the possible genotype
Group O - OO
Group A - AA or AO
Group B - BB or BO
Group AB - AB
What is Landsteiner’s Law?
If an individual lacks the A or B antigen the corresponding antibody is produced by their plasma
Which antibodies are produced by each blood group?
A - anti-B
B - anti-A
O - anti A and anti B
AB - neither
Is rhesus positive or negative more common?
Positive
What is the problem with being rhesus negative?
If a patient is expose to D antigen they will mount an immune response and form an anti-D antibody which can cause a transfusion reaction or haemolytic disease of the new born
What two lab tests help to cross match the blood?
Antisera - specific antibody to identify antigen
Reagent red cells - specific antigen to identify antibody
What happens to IgM in the presence of antigen?
Agglutination
What colour are the antiseras?
Anti A - blue
Anti B yellow
Anti D clear
How is a patients plasma screened for antibodies?
Tested against reagent with known antigens and the additional of anti-human globulin
State the clinical indications for red cells
Symptomatic anaemia Hb <70g/l
Major bleeding
State the clinical indications for platelet
Prophylaxis in bone marrow failure
Bleeding in thrombocytopenia
Prophylaxis before surgery in thrombocytopenia
State the clinical indications for FFP
Treatment of bleeding in patents with coagulopathy
Prophylaxis before surgery in coagulopathy
Massive haemorrhage
Early Trauma
How soon will an acute transfusion reaction occur?
Within 24 hours
What are the signs and symptoms of an acute transfusion reaction?
Symptoms - chills, rigours, rash, flushing, impending doom, collapse, loin pain, respiratory distress
Signs - fever, tachycardia, hypotension
How should all transfusion reactions be managed?
- Stop transfusion
- ABCDE
- Re-check compatibility tag and pack
- Document in notes
What is classed as a severe/life threatening reaction?
Shock - A, B, C compromise
Wrong component
Bacterial contamination
Describe acute haemolytic reactions
Binding of IgM to the antigen on red cells leads to complement activation, lysis of transfused cells and release of inflammatory cytokines
How is acute haemolytic reaction managed?
Stop transfusion and supportive measures
Send to lab to repeat tests
What is TACO?
Transfusion associated circulatory overload
Describe TACO
Within 6 hours of transfusion, presents with respiratory distress and signs of fluid overload
How is TACO treated?
Oxygen, supportive and diuretics
What are the risk factors for TACO?
Old age
Heart failure
Low albumin
Describe mild transfusion reactions
Temp rise >38 or 1/2 degrees
Rash
Continue with transfusion but monitor regularly
What can cause a mild transfusion reaction?
Allergic reaction - anti-histamine
Febrile non -haemolytic - paracetamol
Describe delayed haemolytic reactions
Delayed IgG response to red cell antigen, extravascular haemolysis 5-10 days post transfusion
