Blood transfusion Flashcards
How many allelic forms are present in blood cells?
3
What are the three allelic forms?
Ia, Ib, Io
Which blood group allele is recessive?
Io,
Which blood groups are present?
A, B, AB, O
Which type of antibodies is present within the blood that detects self-blood antigens?
The antibodies have immunoglobulin variable regions specific to antibodies that are not present on the self-erythrocyte.
Which type of antibody activates complement?
IgM
How are A and B antigens?
Formed by the addition of one or other sugar residue onto a common glycoprotein and fucose stem (H antigen)
What is the structure of Group O erythrocytes?
Contains neither A or B sugars- H stem is only present
Which molecule is added to the H antigen? (A group)
N-acetyl galactosamine
Which molecule is added to the H antigen? (B group)
Galactose
What is the genotype for the A antigen?
AA, OA
What is the genotype for the B antigen?
BB, OB
What are anti-antibodies?
Associate and bind onto the respective immunoglobulin molecules within the cell surface membrane, resulting in cellular agglutination
What is Rh factor?
Rhesus factor is an inherited protein located on the cell surface membrane of erythrocytes.
What Rh positive?
Presence of protein
What is Rh-negative?
Lack of protein
What is the most common Rh protein?
D
What does the D gene encode?
Encodes for the D antigen on the erythrocyte surface
What does the d gene encode?
d gene encodes for no antigens
What is the genotype of RhD negative?
dd
What is the genotype of RhD positive?
Dd DD
What are anti-D antibodies?
Synthesized by individuals unable to present RhD antigen, only after they are exposed to the antigen.
What circumstance are anti-D antibodies present?
Upon exposure to the D antigen, transfusion of RhD positive blood
RhD positive fetus
What type of antibody is anti-D?
IgG class antibodies
What are the issues associated with the transfusion of RhD positive with an RhD negative patient?
Delayed hemolytic transfusion reaction with anemia
What is hemolytic disease of the newborn?
RhD negative mother has anti-D subsequent pregnancies involved RhD positive mothers, results in IgG anti-D antibodies crossing the placenta, attach to positive RhD positive fetal red blood cells, resulting in hemolysis of fetal cells
What is the aim to treat RhD negative patients?
Transfuse blood of the same RhD group
Which is the most useful blood group?
Group O negative (RhD negative)- when the patient blood group is not known.
What is antibody screening?
Patient screened to exclude any clinically significant immune antibodies
What is the screened plasma incubated with?
2 or 3 different fully typed screening red cells
What have fully typed screening cells?
Contains all group antigens
What is a negative result?
Any donor blood (ABO & RhD compatible) provided
What is a positive result?
Antibody identified using large panel of red cells, donor units of blood lack corresponding blood antigen are chosen for cross-referencing with recipient plasma prior to transfusion
How is blood tested for ABO group?
Test with anti-A and Anti-B antibodies
Test with anti-D reagent
Which is the age group for donor selection?
17-70 years
Which groups of donors are excluded from blood donors?
Bloodborne diseases (Risk of bacterial, viral or parasitic infections, or drugs)
What is the window period of disease?
Individuals have pathogen however do not present symptoms or detection
What is prion proteins?
Lymphocyte membranes and platelets; prions of variant
CJD diease are found in lymphoreitcular tissues
cjd transmitted by transfusions of blood or blood products in humans, developmentof vCJD
How much volume of blood is collected from donor into sterile plastic back?
450ml
What is added to the blood packets?
Anti-coagulant
What is present within the blood packets?
platelets, red cells, and factor VIII
What is component therapy?
Transfusing units of red cells, conducted by centrifuing, apply pressure to each layer, separating the relevant blood units.
What is one blood unit?
Whole blood-derived from one single blood donation
What is packed with red cells?
SAGM (Saline, adenine, glucose, mannitol), fliod plasma removed,
How long is the shelf-life for red cells?
5 weeks
What temperature are red cells stored at?
4 degrees C
What is a blood giving set?
Has filter to remove debris
Which storage form of plasma is stored at -30degrees c?
Fresh frozen plasma
What is the volume of fresh frozen plasma?
300ml unit
What time period is associated with the freezing of plasma upon donation?
6 hours
What is the purpose of the 6 hour time gap?
Preservation of coagulation factors
What is the shelf-life of fresh frozen plasma?
3 years
What action is required before the administration of fresh frozen plasma?
Thawing
Why should FFP be frozen immediately?
To prevent coagulation factor degeneration at room temperature
What is the purpose of FFP?
Used as a replacement fluid in plasma exchange as well as supplying clotting factors
What is cryoprecipitate?
Prepared from plasma, contains fibrinogen, VWF, VIII, XIII, and fibronectin
What is the thawing temperature for cryoprecipitate?
4-8 degrees
What is the cryoprecipitate shelf-life?
3 years
When is cryoprecipitate used?
Fibrinogen low and patients with excessive bleeding
What is the platelet concentrates?
Pooled platelets:
What are intramuscular injections?
Administered into muscle