Flashcards in Hemolytic Anemias Deck (60)
What is hemolysis?
premature destruction of circulating red cells
What is hemolytic anemia?
hemolysis when the bone marrow cannot compensate
What is compensated hemolytic anemia?
when body has increased the red cell production (reticulocytosis) in the bone marrow
What are the 5 general categories of hemolytic diseases?
Where does extravascular hemolysis occur?
typically in the spleen (reticuloendothelial system), but also sometimes in liver and bone marrow
What gets released when a red cell lyses?
lots of things - but LDH and hemoglobin
What binds to the free hemolglobin to carry to the liver?
So what labs do you see with intravascular hemolysis?
haptoglobin goes down
LDH goes up
products of hemoglobin breakdown go up
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)
What percent of red cells are destroyed extravascularly every day?
WHat cells degrades these RBCs in the spleen?
Do you see a decrease in haptoglobin in pathologic extravascular hemolysis?
yes, because some free Hgb will spill into the circulation
What is the heme broken down to?
bilirubin, so you get an increase in unconjugated bili
What will happen due to that increased unconjugated bilirubin?
increased fecal and urinary urobilinogen
What will you see in the bone marrow due to hemolytic anemia?
erythroid hyperplacia, thinning of cortical bones/bony deformities
Hemolytic anemia will usually be ___chromic and ____cytic
What will RBC morphology look like in hemolytic anemia?
Poikilocytosis (red cell shape changes)
plus extra reticulocytes
What is the term for elevated levels of circulating nucleated red cells?
What happens in a chronic hemolytic anemia-aplastic crisis?
erythroid aplasia iwth severe exacerbation of anemia
usually from parvovirus B19 erythroid maturation arrest
Again, what do you need to correct the reticulocyte count for?
the degree of anemmia
How long can it take for a reticulocyte response to occur after hemolysis becomes severe enough to cause anemia?
up to 72 hrs
WHat produces haptoglobin?
Why might a haptoglobin be normal even if someone is hemolyzing?
haptoglobin is also an acute phase reactant
Low haptoglobin can also be seen in what other conditions?
advanced liver disease
recent massive transfusion
WHy is LDH such a nonspecific test?
it increases due to ANY type of tissue damage
Which LDH isoenzyme is most useful for hemolysis?
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
What are some other causes of indirect bili elevation?
crigler najjar, gilbert's breast milk jaundice
What lab can confirm there's free hgn in the plasma?
easy - a plasma free hgb level