hematology- blood types

Question 1

What two common antigen groups are considered trouble maker?

Answer 1

• ABO (H antigens)

- Rh

Question 2

What are the surface antigens (ABO) called?

Answer 2

• agglutinogens

- agglutinins

Question 3

When are RBC antibodies formed?

Answer 3

• none at birth
• start forming 2-8 months after birth
• maximum at 8-10 years
• more anti-A formed than anti-B agglutinins

Question 4

What happens when ABO mismatch occurs in transfusion?

Answer 4

• surface antigens and opposing antibodies will cause agglutination (clumping) and hemolysis

Question 5

What is Rh+ vs Rh-?

Answer 5

Rh+ has D antigen

Rh- has anti-D antibodies after exposure

Question 6

What does blood type lab order test for?

Answer 6

• ABO type, Rh type

Question 7

What does type and screen lab order test for?

Answer 7

• ABO type, Rh type, Antibody screen

Question 8

What does type and cross lab order test for?

Answer 8

• ABO type, Rh, antibody screen, crossmatch

Question 9

What is forward blood typing?

Answer 9

• using pt’s rbc and adding either anti-A antibody or anti-B antibody to determine pt’s blood type A or B
• using pt’s rbc and adding anti-D antibody to determine whether Rh+ or Rh-

Question 10

What is reverse blood typing?

Answer 10

using pt’s plasma and adding either type A or type B antigens RBCs (antibodies in pt’s plasma should agglutinate to one type of antigen

Question 11

What are the indications for transfusion of blood products?

Answer 11

• dependent on different facility rules
• PRBC (hgb <7, severe anemia symptoms, active hemorrhage
• Platelets (<10,000)
• fresh frozen plasma (correction of coagulopathy)

Question 12

When to stop transfusion if reactions occurs?

Answer 12

• hemolytic transfusion reaction (fevers, chills, pain at site of reaction, n/v, shock, dark urine)
• give lots of IV fluids

Question 13

What happens when father Rh+ and Mother Rh- have a baby?

Answer 13

• Baby could be Rh+
• if mother has not been sensitized to Rh antigen before, she doesn’t have any Rh antibodies. If there is any mixing of fetal and maternal blood during labor, the mother becomes exposed to Rh antigen and makes Rh antibodies IgM which doesn’t pass the placenta but it can develop into IgG which can pass placenta. If the couple decide to have next baby which is Rh+, and if there is any mixing between fetal and maternal blood and the IgG passes through placenta to baby, it can cause agglutination and hemolysis in fetus. This results in hemolytic anemia in fetus.

Question 14

What is erythroblastosis fetalis?

Answer 14

this results when fetal anemia causes hypoxia and increased extra medullary red blood cells production. This causes hepatomegaly and hepatic cell failure as liver ramps up rbc production and decrease other proteins such as albumin production resulting in increased intrahepatic oncotic pressure and portal hypertension. This results in ascites, hypoxia, placental thickening and pericardial effusion

Question 15

What is the prevention of fetal anemia?

Answer 15

• Rhogam (monoclonal antibody) administered to mother who is Rh-. Rhogam binds to fetal RBC epitopes to prevent B-cell terminal differentiation IgG production