Blood Transfusion Flashcards
What blood components does 1 donation of blood contain?
red cells
platelets
plasma
white cells
When does plasma become fresh frozen plasma?
if it is frozen within 8 hours of collection
contains same concentration of coagulation proteins that was in donors blood
What blood products can be obtained by subjecting a batch of blood to manufacturing?
albumin
Ig
prothrombin complex concentrates
How many donors do you expose the patient to when giving them blood products?
thousands
What is used to separate donor blood into components?
anticoagulant
How often can someone give blood?
every 12 weeks
max 5 times per year
What are the standard donor criteria?
must be able to spare 465mls of blood
min weight 50kg
Hb - 135 for men, 125 for women
When blood is centrifuged, from bottom to top, what order are the components?
bottom - red cells (most dense)
middle - white cells and platelets
top - plasma cells (least dense)
What temperature are red cells kept at?
4’C
+/- 2’C
What is the shelf life of red cells?
35 days
What happens if red cells are removed from storage for more than 30 mins?
must be transfused or thrown away
What temperature are platelets kept at?
22’C
What is the shelf life of platelets?
7 days if bacterial monitoring system
What temperature is fresh frozen plasma kept at and for how ling?
-30’C
up to 3 years
What must happen to fresh frozen plasma before transfusion?
must be thawed - takes about 40 mins
On what chromosome is the gene determining ABO blood group?
chromosome 9
How is blood group determined?
agglutination - giving antibody to someone of the same blood type e.g. anti A to A blood group - cells stick together
Describe the red cell membrane in group A, B, O and AB blood groups?
group A - carry A antigen
group B - carry B antigen
group AB - carry A and B antigens
group O - carries neither A or B antigens
What happens when group A red cells are exposed to A and B antigens?
recognises B antigen as foreign, develops anti B antibodies
What happens when group B red cells are exposed to A and B antigens?
recognises A antigen as foreign, develops anti A antibodies
What happens when group AB red cells are exposed to A and B antigens?
don’t recognise either as foreign, no antibodies
What happens when group O red cells are exposed to A and B antigens?
recognise both A and B antigens as foreign, develops anti A and anti B antibodies
When do antibodies to A and B antigens start to develop?
about 6 months,
antibodies produced depends on blood type
What blood type is the universal recipient? Why?
AB
doesn’t have antibodies to A or B antigens
What blood type is the universal donor? Why?
O
doesn’t have A or B antigens, no blood groups have antibodies against it
What Ig are naturally occurring ABO antibodies?
IgM
small amount of IgG
What is dominant: A, B or O?
A and B are codominant
O is recessive
On which chromosome is the gene determining Rh(D) blood type?
chromosome 1
What happens if a Rh(D) negative mother has a Rh(D) positive fetus?
leak of RBCs may occur, anti D antibodies formed in mother
in later pregnancies, can cross the placenta and attack baby’s Rh(D) positive red blood cells –> haemolysis
(haemolytic disease of the newborn)
can occur in first pregnancy due to leaks e.g. threatened miscarriage
How can you prevent haemolytic disease of the newborn/rhesus disease?
give anti D to Rh -ve mothers at 28 and 34 weeks
What happens in an acute haemolytic transfusion reaction?
activation of complement, kinase and coagulation systems in response to circulating antibody to donor blood
What happens when the complement cascade is activated?
release of C3a and C5a
causes vasodilation and increased vascular permeability
and release of serotonin and histamine
fever, chills, shock, hypotension
What happens when the kinin system is activated?
bradykinin release –> arteriolar dilation, increased vascular permeability
hypotension
What happens when the coagulation pathways are activated?
thromboplastic material from haemolysed RBCs cause indiscriminate activation of coagulation –> DIC
What are some features of an acute haemolytic transfusion reaction?
dizziness/fainting tachycardia, tachypnoea, hypotension pyrexia, rigors, sweating pain at infusion site headaches, chest pain
How do you manage an acute haemolytic transfusion reaction?
stop tranfusion
IV fluids
blood tests
What is a delayed haemolytic transfusion reaction?
similar to acute
happens 5-10 days layer
What is a febrile non-haemolytic transfusion reaction?
occurs due to contaminating WBCs
common, non life threatening
rapid increase in temp
What is an urticarial transfusion reaction? How is it managed?
mast cell, IgE response to plasma proteins
rash/weal
slow transfusion, antihistamines
Who is at risk of circulatory overload? How do you manage it?
elderly people
CCF
decrease transfusion rate, diuretics?
