7: Blood Groups, Blood Typing & Cross-Matching & transfusion Flashcards Preview

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Flashcards in 7: Blood Groups, Blood Typing & Cross-Matching & transfusion Deck (28)
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0
Q

How many different blood groups are there?

A

30 different blood group systems & 600+ antigens contained within these systems–>Many of these antigens are extremely rare

1
Q

What is a blood type (group)?

A

A classification of blood based on the presence (+) or absence (-) of inherited antigenic (antigens) substances on the surface of the RBCs.

-Antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system.

2
Q

What is the most important blood group systems in transfusion medicine ?

A

ABO and Rhesus (Rh)

3
Q

What is the ABO system?

A
  • The genes for ABO are inherited in a Mendelian manner

- ABO system is SUGAR based, rather than protein based!

4
Q

What is the most common blood type? List the other types as well.

A
O+ = 37.4
A+= 35.7
B+= 8.5
O-= 6.6
A-= 6.3
AB+ 3.4
B- = 1.5
AB- = 0.6
5
Q

What is the Rhesus (Rh) System?

A

Group system is more complex than ABO & is the second most important blood group system in terms of transfusion medicine based of its high immunogenicity.

6
Q

How many Rh antigens are there?

A

Approx. 50 Rh antigens but only 5 are common

name D, C , c, E , and e

7
Q

What is Rh Positive and Rh Negative used for ?

A

Rh positive is used for individuals who are Rhesus (D) positive and Rh negative afro those who do not possess the Rhesus (D) antigen

8
Q

What is the Donor for O+?

A

O- and O+

9
Q

What were these blood groups named after? And what are they?

A

Named after the patients in whom the corresponding antibodies were initially encountered.

1) Kell (K)
2) Duffy (Fy)
3) Lewis

10
Q

What is Kell (K)?

A

Peptides that are highly immunogenic, but not as much as Rh; individuals are either K+ or K-

11
Q

What are Duffy (Fy) ?

A

The main antigens, Fya and Fyb; individuals can be either Fy (a+b), Fy (a-b+), Fy (a-b-)

12
Q

What are Lewis group systems?

A

2 types of Lewis antigens:

1) Lewis a and Lewis b;
2) individuals can be Lewis (a+b-)
3) Lewis (a+b+)
4) Lewis (a-b-)

13
Q

Today what components is donated blood separated into?

A

Processed to produce the separate different components that might be required for medical or surgical purposes;

1) Red cells
2) White cells
3) Platelets
4) Fresh frozen plasma
5) Heat treated plasma

14
Q

What is are examples of transfusion reactions ?

A

1) Hemolytic
2) Non-hemolytic
3) Allergic
4) Due to Volume Overload
5) Transfer of Bacteria

15
Q

Why can the Hemolytic reaction occur in transfusion reactions?

A

Due to an antigen-antibody reaction as a result of an incompatible transfusion, resulting in severe or fatal intravascular hemolysis

*****Concurrent w/ kidney failure!!

16
Q

Why can the Non-hemolytic reaction occur in transfusion reactions?

A

Die to damaged blood products that release high levels of cytokines, leading to fever and chills; usually benign

17
Q

Why can the Allergic reaction occur in transfusion reactions?

A

Lading to rashes and itching; usually benign

18
Q

What can result Due to Volume Overload occur in transfusion reactions?

A

Could cause pulmonary EDEMA; Outcome depends on other conditions

19
Q

What can the Transfer of Bacteria lead to in transfusion reactions?

A

Leads to Endotoxemia (as a result of free bacterial toxins) & Septicemia; potentially fatal

20
Q

What are the Test used in Transfusion Medicine?

A

1) Blood grouping
2) Antibody screen
3) Cross-Match

21
Q

Why were these tested used in transfusion?

A

To ensure that any blood transfused into a recipient is compatible w/ the donor & will not cause a transfusion reaction

22
Q

What is HDN? Why does it occur?

A
  • Hemolytic disease of the newborn
  • An important problem related to the Rh factor occurs in pregnant Rh- woman who are carrying Rh+ babies. Mother begins to produce anti-Rh agglutinins which often affects her second pregnancy. Her anti-Rh agglutinins may pass thru the placenta & agglutinate the fetal RBCs.
23
Q

What happens to the fetus in HDN?

A

***Agglutinated RBCs hemolyze, and the “2nd” baby is born with severe anemia.

  • First baby results in the delivery of a health baby.
  • Then after birth of if a miscarriage occurs, placental tearing exposes mother to Rh+ fetal blood that begins to make the anti-Rh agglutinins.
24
Q

How is HDN (Hemolytic disease of the newborn) prevented/treated?

A

Easier to prevent than to treat!

  • If an Rh- woman gives birth to (or miscarries an Rh+ child she can be given an Rh immune globulin (sold under trade names like, **RhoGAM & Gamulin*
  • The immune globulin binds fetal RBC agglutinogens so they cannot stimulate her immune system to produce anti-Rh agglutinins.
25
Q

What have physicians started giving for HDN complications?

A

They give Rh immune globulin throughout any pregnancy in which the MOTHER is Rh- and FATHER is Rh+

26
Q

What happens to woman immune system when Rh+ gets in her blood stream from fetus?

A
  • Woman becomes sensitized antibodies form to fight Rh+ blood cells!
  • In the next Rh+ pregnancy, antibodies attack fetal blood cells
27
Q

a) When one has the Rh factor what is their Rhesus blood type?
b) When one does not carry the Rh factor what is their Rhesus blood type?

A

a) Rh +

b) Rh-