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Flashcards in Hemolytic Anemias Deck (60)
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1

What is hemolysis?

premature destruction of circulating red cells

2

What is hemolytic anemia?

hemolysis when the bone marrow cannot compensate

3

What is compensated hemolytic anemia?

when body has increased the red cell production (reticulocytosis) in the bone marrow

4

What are the 5 general categories of hemolytic diseases?

membrane defects
metabolic defects
hemoglobin defects
mechanical destruction
immune destruction

5

Where does extravascular hemolysis occur?

typically in the spleen (reticuloendothelial system), but also sometimes in liver and bone marrow

6

What gets released when a red cell lyses?

lots of things - but LDH and hemoglobin

7

What binds to the free hemolglobin to carry to the liver?

haptoglobin

8

So what labs do you see with intravascular hemolysis?

haptoglobin goes down
LDH goes up
products of hemoglobin breakdown go up

9

What effects in the urine can be seen from hemolysis?

when severe, hemoglobinuria (alpha-beta dimers in the urine) and hemosiderinuria (RTCs take up and metabolize the dimers to form hemosiderin granules in the urine - not good for the kidney)

10

What percent of red cells are destroyed extravascularly every day?

11%

11

WHat cells degrades these RBCs in the spleen?

macrophages

12

Do you see a decrease in haptoglobin in pathologic extravascular hemolysis?

yes, because some free Hgb will spill into the circulation

13

What is the heme broken down to?

bilirubin, so you get an increase in unconjugated bili

14

What will happen due to that increased unconjugated bilirubin?

gallstones
biliary obstruction
increased fecal and urinary urobilinogen

15

What will you see in the bone marrow due to hemolytic anemia?

erythroid hyperplacia, thinning of cortical bones/bony deformities

16

Hemolytic anemia will usually be ___chromic and ____cytic

normochromic
normocytic

17

What will RBC morphology look like in hemolytic anemia?

Poikilocytosis (red cell shape changes)

plus extra reticulocytes

18

What is the term for elevated levels of circulating nucleated red cells?

erythroblastemia

19

What happens in a chronic hemolytic anemia-aplastic crisis?

erythroid aplasia iwth severe exacerbation of anemia

usually from parvovirus B19 erythroid maturation arrest

20

Again, what do you need to correct the reticulocyte count for?

the degree of anemmia

21

How long can it take for a reticulocyte response to occur after hemolysis becomes severe enough to cause anemia?

up to 72 hrs

22

WHat produces haptoglobin?

the liver

23

Why might a haptoglobin be normal even if someone is hemolyzing?

haptoglobin is also an acute phase reactant

24

Low haptoglobin can also be seen in what other conditions?

advanced liver disease
recent massive transfusion
genetic variant
megaloblastic anemias
hematoma breakdown

25

WHy is LDH such a nonspecific test?

it increases due to ANY type of tissue damage

26

Which LDH isoenzyme is most useful for hemolysis?

LDH1

27

Why does the unconjugated biliruin increase if the liver is just fine in hemolysis?

because the unconjugated bili is so high the liver can't keep up

28

What are some other causes of indirect bili elevation?

crigler najjar, gilbert's breast milk jaundice

29

What lab can confirm there's free hgn in the plasma?

easy - a plasma free hgb level

30

What kind of other anemia does Dr. D get all hot and bothered about mistaking for hemolytic anemia

megaloblastic anemia (bc the big precursors get broken down in the bone marrow)