Blood Transfusion Flashcards
What is the minimum criteria for blood transfusion?
50kg weight
Hb 135g/L men
Hb 125g/L women
How are red cells stored?
at 4 degrees for 5 days
How is FFP stored?
-30 degrees for 3 years
How are platelets stored?
22 degreees for 7 days with agitation
What chromosome are is blood type found on?
chromosome 9
What blood group genes are co dominant?
A and B
What is the role of A and B?
codes for transferase which modifies a precursor called H substance on red cell membranes
What is a blood type genotype?
what genes are present - AA, AB etc
What is a blood type phenotype?
what antigens are deteted - group A, group B
What is the universal blood?
O negative
What is Landsteiners Law?
when an individual lacks an A or B antigen the corresponding antibody is produced in plasma
this means that these naturally occuring antibodies cause haemolysis of a RBC expressing the other antigen
Which of the RhD alleles are silent?
d
What geneotype must you have to be RhD +ve?
Dd or DD
What is used for pre transfusion testing?
Antisera and Reagent red cells
What is Antisera?
reagent with a known antibody specificity to identify antigens present on cells
What is Reagent red cells?
red cells with known antigen specificity to identify antibodies present in plasma
What are the indications for transfusion?
symptomatic anaemia <70g/L (80 if cardiac disease)
major bleeding
What are the indications for platelet infusion?
aim = >10
prophylaxis in patients with bone marrow failure and low platelet counts
treatment of bleeding in thrombocytopeanic patients
prophylaxis prior to surgery/procedure in thrombocytopenic patients
When are FFP transfusions indicated?
treatment of bleeding in a patient with coagulopathy
prophylaxis prior to surgery in pt with coagulopathy
management of massive haemorrhage
What is an acute transfusion reaction?
chills, rigors, rash, flushing, collapse, loin pain, resp distress, fever, tachycardia, hypertension, tachypneoa
How is an acute transfusion reaction managed?
stop transfusion and ABCDE
What is an acute haemolytic transfusion reaction (AHTR)?
ABO or RhD incompatible transfusion
results in haemolysis and complement activation
What is a transfusion associated circulatory overload (TACO)?
resp distress within 6 hours of transfusion
raised BP and JVP
positive fluid balance
What are the risk factors for TACO?
elderly cardiac failure low albumin renal impairment fluid overload
How is TACO managed?
supportive care
diuretics
What is a mild transfusion reaction?
isolated temp rise >38 or rash
How do you manage a mild transfusion reaction?
continue transfusion but give paracetamol/antihistamines
