Blood Transfusion Flashcards
why can blood groups provoke an immune response?
because they arise from antigens
describe type A antigens
> N-acetylgalatosamine
> co-dominant
describe type O antigens
> non functioning allele
> recessive
describe type B antigens
> galactose
> co-dominant
what happens when a RhD -ve individual is exposed to RhD + cells?
they can make anti -D antibodies
what do ABO genes code for?
glycosyltransferase (AB genes code for the transferase enzyme and glycans are added to the proteins or the lipids on the red cell)
what blood can a group A patient receive?
> A
> O
what blood can a group B patient receive?
> B
> O
what blood can a group AB patient receive?
> A
B
AB
O
what blood can a group O patient receive?
> O
what fresh frozen plasma can group A receive?
> A
> AB
what fresh frozen plasma can group B receive?
> B
> AB
what fresh frozen plasma can group AB receive?
> AB
what fresh frozen plasma can group O receive?
> A
B
AB
O
what are the indications for red cell transfusion?
> correct severe acute anaemia
improve quality of life in un-correctable anaemia
prepare for surgery/speedy recovery
reverse damage by patients own cells
what screening questions are asked in blood donation?
> tattoos > travel > sex > age > sexual behaviour
what is always screened for in blood donation?
> Hep B/C/E
HIV
syphilis
what is variably screened for in blood donation?
> zika
malaria
west nile virus
what is group and screening?
> checking RhD type
checking ABO type
checked against historical records
screen for alloantibodies
what tests are used in group and screening?
> coombs test
> gel’s column and automation
describe the availability of red cells in hospital
> Minutes: O RhD -ve cells and AB plasma
urgent: type specific
Non-Urgent: full cross match
Massive Haemorrhage: 6 units of red cells, 1 unit of platelets and 4 units of FFP
what is haemolytic disease of the newborn?
the baby is RhD +ve and the mother is -ve so maternal antibodies antiD antibodies develop as IgG crosses the placenta.
what is neonatal alloimmune thrombocytopenia?
uncommon but it is the same process as haemolytic disease of the newborn but involving platelets.
intracellular haemorrhage
how is haemolytic disease of foetus and newborn managed?
> prevention with prophylactic anti-D at 28/40 weeks > treatment: - carful monitoring with doppler US - interuterine transfusion - antibody titres
how are blood transfusion reactions managed?
> stop the transfusion
give antihistamine if there is urticaria
check the patients identity against label
antipyretic
how should you manage dyspnoea as a transfusion reaction?
> O2
diuretic
ventilation
adrenaline
a patient goes into shock after reacting to a transfusion. how is this managed?
> ventilation > antibiotics > FFP/platelets > adrenaline > IV fluids
what is in the buffy coat?
> platelets
> WBC
what is in the plasma?
> albumin
antibodies
clotting and coag. factors
at what temperature are red blood cells stored at?
4 degrees Celsius
over what time period are RBC transfused over?
2-4 hours
how are platelets stored?
at 22 degrees Celsius for 7 days
what are some indications for platelets transfusion?
> bone marrow failure
surgery prophylaxis
cardiopulmonary bypass (only if bleeding)
major haemorrhage
over what period of time are platelets transfused over?
20-30mins
what are some indications for fresh frozen plasma?
> major haemorrhage
DIC
bleeding
prophylaxis
