266b RBC transfusions Flashcards Preview

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Flashcards in 266b RBC transfusions Deck (15):
1

RBC hemolysis - intra vs extravascular

intra - IgM/G binds --> activates compliment--> MAC forms pores

extravascular - IgG binds --> RBCs are phagocytized (spleen)

2

RBC hemolysis - intra vs extravascular

intra - IgM/G binds --> activates compliment--> MAC forms pores

extravascular - IgG binds --> RBCs are phagocytized (spleen)

3

ABO incompatible RBC transfusion effects?

rapid hemolysis from IgM activating complement

systemic inflammation - hypotension, shock
clotting activated (DIC)
renal tubule injury - acute tubular necrosis

4

ABO vs Rh D antibodies - which occur naturally?

ABO antibodies occur naturally

Rh D - acquired from exposure of Rh- to Rh+ blood (give Rh immune globulin to mother --I blocks antibody production)

must give Rh- RBC to Rh- patients unless emergency and especially to females of childbearing age

5

Autoimmune hemolytic anemia testing - direct coombs test

anti-Ig antibody (Coombs reagent) added to patient’s blood. RBCs agglutinate if RBCs are coated with Ig.

6

emergency RBC transfusion - what do you use?

Group O, Rh- RBCs (at least for females)

7

O blood group

Neither A nor B antigen on RBC surface; both antibodies in plasma

“universal donor” of RBCs

“universal recipient” of plasma.

8

Rh blood group - what is the issue? what can be done to prevent it? what Ig crosses the placenta?

Rh antigen on RBC surface. Rh− mothers exposed to fetal Rh+ blood (often during delivery) may make anti-Rh IgG.

In subsequent pregnancies, anti-Rh IgG crosses the placenta, causing hemolytic disease of the newborn (erythroblastosis fetalis) in the next fetus that is Rh+.

Give mother Rho immune globulin during pregnancy

IgG crosses placenta, IgM doesn't (anti-A/B)

9

ABO vs Rh D antibodies - which occur naturally?

ABO antibodies occur naturally

Rh D - acquired from exposure of Rh- to Rh+ blood (give Rh immune globulin to mother --I blocks antibody production)

must give Rh- RBC to Rh- patients unless emergency and especially to females of childbearing age

10

Autoimmune hemolytic anemia testing - direct coombs test

anti-Ig antibody (Coombs reagent) added to patient’s blood. RBCs agglutinate if RBCs are coated with Ig.

11

Autoimmune hemolytic anemia testing - indirect coombs test

normal RBCs added to patient’s serum. If serum has anti-RBC surface Ig, RBCs agglutinate when anti-Ig antibodies (Coombs reagent) added.

12

emergency RBC transfusion - what do you use?

Group O, Rh- RBCs (at least for females)

13

O blood group

Neither A nor B antigen on RBC surface; both antibodies in plasma; “universal donor” of RBCs, “universal recipient” of plasma.

14

Rh blood group - what is the issue? what can be done to prevent it? what Ig crosses the placenta?

Rh antigen on RBC surface. Rh− mothers exposed to fetal Rh+ blood (often during delivery) may make anti-Rh IgG.

In subsequent pregnancies, anti-Rh IgG crosses the placenta, causing hemolytic disease of the newborn (erythroblastosis fetalis) in the next fetus that is Rh+.

Give mother Rho immune globulin during pregnancy

IgG crosses placenta, IgM doesn't (anti-A/B)

15

acute bleeding rx?

1 - intravascular blood volume via iv fluids (avoid hypovolemia, hypoperfusion
**early Hct doesn't reflect blood loss**

RBC transfusions when blood loss reaches 30% (1500 mL)