Flashcards in Anemia 2 Deck (19):
macrocytic anemia: why are the cells big (in general)
disconnect between cell content and membrane quantity (RBC is still large after losing its nucleus, organelles)
vit B12/folate deficiency, myelodysplasia, drugs - pathophysl
impaired DNA synthesis: nuclear and cytoplasm maturation are mismatched
alcoholism, liver disease, thyroid disturbances: pathophysl
altered/increased content in cell membrane = redundant membrane
reticulocytes: why are they bigger
(already lost nucleus) contain residual protein synthesis machinery = haven't yet achieved final compact RBC size
limitations of MCV
lists aren't mutually exclusive, and usually the patient will be normocytic - use is to suggest further testing
bone marrow response: measured by?
all patients with persistent unexplained anemia: order what 2 things
blood film. reticulocyte count.
what is the bone marrow response to anemia
low O2 detected by kidney = EPO production to stimulate RBC production. Within 2/3 days, young RBCs aka reticulocytes should be detectable in blood
limitations of reticulocyte count
hard to know what an appropriate reticulocyte response is in a given situation
rule of thumb for reticulocyte counts
someone with anemia: should go above 2%, if not their bone marrow has not adequately responded
failure of adequate reticulocyte production indicates?
bone marrow isn't optimally functioning
classifying anemia by reticulocyte count (2)
low count = hypoproliferative anemia aka marrow can't respond. high = proliferative anemia = marrow is responding, but cells are being lost or destroyed too fast
causes of hypoproliferative anemia
abnormal marrow, hemantinic deficiency, low metabolic state, low erythropoietin (renal failure), anemia of inflammation
causes of proliferative anemia
bleeding, hemolysis, response to hematinic therapy
anemia by pathologic category: what causes increased loss/destruction
bleeding: obvious or occult. destruction by hemolysis
anemia by pathologic category: what causes sequestration
cells sequestered in the spleen. can also be dilutional: from pregnancy, or large IV boluses like getting saline
anemia from blood loss: chronic blood loss leads to?
iron deficiency. usually iron is in RBCs and is recycled
hemolysis: two categories and examples
extrinsic: immune mediated, drugs/toxins, osmotic, mechanical. intrinsic: enzyme deficiency, hemoglobinopathy, membrane protein defects - usually congenital.