Blood groups and transfusion Flashcards
What structures exist on the surface of red cells to determine group
Sugar residues
Proteins
What blood group system do sugar residues determien
ABO
What blood group system do proteins determine
Proteins
Define red cell antigens
Substances on surface of red cell that can stimulate formation of antibodies
Define antibodies in terms of blood groups
Immunoglobins in palsma which react specifically with their antigen (eg A antigen adn anti- A antibody)
Define autoantibodie
Antibodies that react with antigens on persons own red cells
Define alloantibodies
Produced by the person against antigens not present on persons own red cells
What type of antibodies are anti A and B?
Naturally occuring antibodies IgM
What is contained in plasma of blood group A
Anti-B
What is contained in plasma of blood group B
Anti-A
What is contained in plasma of blood group O
Anti- B and Anti- A
What is contained in plasma of blood group AB
No ABO antibodies
What acclutinates group group A
Anti-A
What acclutinates group B
Anti-B
What acclutinates blood gropu AB
Anti-A and Anti-B
What agglutinates blood group O
Neither anti- A or anti- B
What is meant by ABO phenotype?
The antigens that can be detected (eg blood group a has A antigens)
Genetics of blood types A and B
They are co-dominant
What is the genotype of blood group A
AA or AO
What is the genotype of blood group B
BB or BO
What is the genotype of blood group AB
AB
What is the genotype of blood group O
OO
Distribution of blood types in caucasian people
A: 45%
B: 8%
AB: 3%
0: 44%
Distribution of blood types in asian people
A: 24%
B: 38%
AB: 16%
O: 22%
What 3 antigens determine rhesus blood group
C or c
D or no D (d)
E or e
How are antigens in rhesus blood groups inherited
As a triplet
What type of antibodies are involved in rhesus blood groups
Immune antibodies- they will only be produced if exposed to antigen through transfusion, pregnancy or transplantation
What 2 genes are involved in rhesus group
RhD and RhCE
Is cde/cde genotype positive or negative
Negative
Is CDe/cdE positive or negative
Positive
Name 4 rhesus positive genotypes
CDe/ cDE
CDe/cdE
CcDE/ Cde
CDE/ cde
Name a rhesus negative genotypes
Cde/cde
Are majority of people rhesus positive or negative
Positive
What is haemolytic disease of the new born
Severe disease leading to still birth or severe brain damage in the child
Most common cause of haemolytic disease of new born?
Anti- D antibody
What happens to a rhesus positive mother carrying her first rhesus negative child
The immune system is sensitised to D antigen
What happens to a rhesus positive mother carrying her second rhesys negative child
Anti-D is stimulated
Crosses the placenta
Destroys foetal red cell leading to Anti-D immunoglobulin prophylaxis within 72 hours of birth
How is haemolytic disease of the new born now prevented
All Rh negative mothers now get prophylatic anti-D pregnancy
6 reasons somebody may require blood transfusion
Anaemia Bone marrow failure Anaemia of prematurity Sickle cell Malaria Acute blood loss
5 dangers of blood transfusion
Infection transmission Danger of alloimmunisation (antibody production) that may compromise further transfusions Danger of incompatible transfusion Danger of iron overload Danger of circulatory overload
What blood groups can blood group O give to?
All blood groups
What blood groups can blood group A give to?
A or AB
What blood groups can blood group B give to?
B or AB
What blood groups can blood group AB give to?
just AB
What blood groups can Rh positive receive
Positive or negative
What blood groups can Rh negative receive
Usually just negative
Can only give positive to males requiring massive transfusion
What is lifespan of platelets when stored at room temp
5 days
Why is it advised to give platelets to same blood group?
In case residual red cells are present
What protocols must happen when taking blood from a patient?
- Confirm id
- Label tube with full name, NOB, hospital record number
- No sticky name labels
- Sign both form and tube
What must be organised before a transfusion can be undergone?
- Blood grouping (both ABO and rhesus)
- Antibody screening
What must be monitoring during a transfusion
Pulse
BP
Temp
What is an indirect antiglobin test
- Used to screen for atypical antibodies in plasma
- Plasma mixed with group O cells as this expresses all common blood group antigens
- If antibody is present it will bind to antigen on detector red cell
What does a rapid temp spike of >40 degrees C suggest?
Intravascular haemolysis
Symptoms of intravascular haemolysis
Restless Flushing Anxiety Abdominal pain Pain at venepuncture site
Signs of intravascular haemolysis
Fever
Hypotension
Oozing from venepuncture site
Haemoglobinuria
Treatment of acute transfusion reaction
STOP TRANSFUSION
IV saline to control hypotension
Frusemide to maintain renal perfusion
Treat any resultant disseminated intravascular coagulation
Where should transfusion problems be reported to?
MRHA
SHOT