Blood Transfusion

Question 1

What blood components does 1 donation of blood contain?

Answer 1

red cells
platelets
plasma
white cells

Question 2

When does plasma become fresh frozen plasma?

Answer 2

if it is frozen within 8 hours of collection

contains same concentration of coagulation proteins that was in donors blood

Question 3

What blood products can be obtained by subjecting a batch of blood to manufacturing?

Answer 3

albumin
Ig
prothrombin complex concentrates

Question 4

How many donors do you expose the patient to when giving them blood products?

Answer 4

thousands

Question 5

What is used to separate donor blood into components?

Answer 5

anticoagulant

Question 6

How often can someone give blood?

Answer 6

every 12 weeks

max 5 times per year

Question 7

What are the standard donor criteria?

Answer 7

must be able to spare 465mls of blood
min weight 50kg
Hb - 135 for men, 125 for women

Question 8

When blood is centrifuged, from bottom to top, what order are the components?

Answer 8

bottom - red cells (most dense)
middle - white cells and platelets
top - plasma cells (least dense)

Question 9

What temperature are red cells kept at?

Answer 9

4’C

+/- 2’C

Question 10

What is the shelf life of red cells?

Answer 10

35 days

Question 11

What happens if red cells are removed from storage for more than 30 mins?

Answer 11

must be transfused or thrown away

Question 12

What temperature are platelets kept at?

Answer 12

22’C

Question 13

What is the shelf life of platelets?

Answer 13

7 days if bacterial monitoring system

Question 14

What temperature is fresh frozen plasma kept at and for how ling?

Answer 14

-30’C

up to 3 years

Question 15

What must happen to fresh frozen plasma before transfusion?

Answer 15

must be thawed - takes about 40 mins

Question 16

On what chromosome is the gene determining ABO blood group?

Answer 16

chromosome 9

Question 17

How is blood group determined?

Answer 17

agglutination - giving antibody to someone of the same blood type e.g. anti A to A blood group - cells stick together

Question 18

Describe the red cell membrane in group A, B, O and AB blood groups?

Answer 18

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

Question 19

What happens when group A red cells are exposed to A and B antigens?

Answer 19

recognises B antigen as foreign, develops anti B antibodies

Question 20

What happens when group B red cells are exposed to A and B antigens?

Answer 20

recognises A antigen as foreign, develops anti A antibodies

Question 21

What happens when group AB red cells are exposed to A and B antigens?

Answer 21

don’t recognise either as foreign, no antibodies

Question 22

What happens when group O red cells are exposed to A and B antigens?

Answer 22

recognise both A and B antigens as foreign, develops anti A and anti B antibodies

Question 23

When do antibodies to A and B antigens start to develop?

Answer 23

about 6 months,

antibodies produced depends on blood type

Question 24

What blood type is the universal recipient? Why?

Answer 24

AB

doesn’t have antibodies to A or B antigens

Question 25

What blood type is the universal donor? Why?

Answer 25

O

doesn’t have A or B antigens, no blood groups have antibodies against it

Question 26

What Ig are naturally occurring ABO antibodies?

Answer 26

IgM

small amount of IgG

Question 27

What is dominant: A, B or O?

Answer 27

A and B are codominant

O is recessive

Question 28

On which chromosome is the gene determining Rh(D) blood type?

Answer 28

chromosome 1

Question 29

What happens if a Rh(D) negative mother has a Rh(D) positive fetus?

Answer 29

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

Question 30

How can you prevent haemolytic disease of the newborn/rhesus disease?

Answer 30

give anti D to Rh -ve mothers at 28 and 34 weeks

Question 31

What happens in an acute haemolytic transfusion reaction?

Answer 31

activation of complement, kinase and coagulation systems in response to circulating antibody to donor blood

Question 32

What happens when the complement cascade is activated?

Answer 32

release of C3a and C5a
causes vasodilation and increased vascular permeability
and release of serotonin and histamine
fever, chills, shock, hypotension

Question 33

What happens when the kinin system is activated?

Answer 33

bradykinin release –> arteriolar dilation, increased vascular permeability
hypotension

Question 34

What happens when the coagulation pathways are activated?

Answer 34

thromboplastic material from haemolysed RBCs cause indiscriminate activation of coagulation –> DIC

Question 35

What are some features of an acute haemolytic transfusion reaction?

Answer 35

dizziness/fainting 
tachycardia, tachypnoea, hypotension 
pyrexia, rigors, sweating 
pain at infusion site
headaches, chest pain

Question 36

How do you manage an acute haemolytic transfusion reaction?

Answer 36

stop tranfusion
IV fluids
blood tests

Question 37

What is a delayed haemolytic transfusion reaction?

Answer 37

similar to acute

happens 5-10 days layer

Question 38

What is a febrile non-haemolytic transfusion reaction?

Answer 38

occurs due to contaminating WBCs
common, non life threatening
rapid increase in temp

Question 39

What is an urticarial transfusion reaction? How is it managed?

Answer 39

mast cell, IgE response to plasma proteins
rash/weal
slow transfusion, antihistamines

Question 40

Who is at risk of circulatory overload? How do you manage it?

Answer 40

elderly people
CCF
decrease transfusion rate, diuretics?