Anemia 2

Question 1

macrocytic anemia: why are the cells big (in general)

Answer 1

disconnect between cell content and membrane quantity (RBC is still large after losing its nucleus, organelles)

Question 2

vit B12/folate deficiency, myelodysplasia, drugs - pathophysl

Answer 2

impaired DNA synthesis: nuclear and cytoplasm maturation are mismatched

Question 3

alcoholism, liver disease, thyroid disturbances: pathophysl

Answer 3

altered/increased content in cell membrane = redundant membrane

Question 4

reticulocytes: why are they bigger

Answer 4

(already lost nucleus) contain residual protein synthesis machinery = haven’t yet achieved final compact RBC size

Question 5

limitations of MCV

Answer 5

lists aren’t mutually exclusive, and usually the patient will be normocytic - use is to suggest further testing

Question 6

bone marrow response: measured by?

Answer 6

reticulocyte count

Question 7

all patients with persistent unexplained anemia: order what 2 things

Answer 7

blood film. reticulocyte count.

Question 8

what is the bone marrow response to anemia

Answer 8

low O2 detected by kidney = EPO production to stimulate RBC production. Within 2/3 days, young RBCs aka reticulocytes should be detectable in blood

Question 9

limitations of reticulocyte count

Answer 9

hard to know what an appropriate reticulocyte response is in a given situation

Question 10

rule of thumb for reticulocyte counts

Answer 10

someone with anemia: should go above 2%, if not their bone marrow has not adequately responded

Question 11

failure of adequate reticulocyte production indicates?

Answer 11

bone marrow isn’t optimally functioning

Question 12

classifying anemia by reticulocyte count (2)

Answer 12

low count = hypoproliferative anemia aka marrow can’t respond. high = proliferative anemia = marrow is responding, but cells are being lost or destroyed too fast

Question 13

causes of hypoproliferative anemia

Answer 13

abnormal marrow, hemantinic deficiency, low metabolic state, low erythropoietin (renal failure), anemia of inflammation

Question 14

causes of proliferative anemia

Answer 14

bleeding, hemolysis, response to hematinic therapy

Question 15

anemia by pathologic category: what causes increased loss/destruction

Answer 15

bleeding: obvious or occult. destruction by hemolysis

Question 16

anemia by pathologic category: what causes sequestration

Answer 16

cells sequestered in the spleen. can also be dilutional: from pregnancy, or large IV boluses like getting saline

Question 17

anemia from blood loss: chronic blood loss leads to?

Answer 17

iron deficiency. usually iron is in RBCs and is recycled

Question 18

hemolysis: two categories and examples

Answer 18

extrinsic: immune mediated, drugs/toxins, osmotic, mechanical. intrinsic: enzyme deficiency, hemoglobinopathy, membrane protein defects - usually congenital.

Question 19

hemolytic workup: order what tests?

Answer 19

blood film. reticulocyte count LDH. total and unconjucated bilirubin. haptoglobin. DAT aka direct antiglobulin test