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Flashcards in Anemia Deck (40)
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1

define anemia

  • male Hb < 13.5 g/dL
  • female Hb < 12 g/dL

2

what are clinical consequences of anemia

  • conjunctival pallor
  • atrophic glossitis
  • fatigue → lethary (depending on severity) 
  • bounding pulses, palpitations, chest pain 
  • high output congestive heart failure, MI (severe anemia) 

3

what are the essential building blocks in heme production and RBC maturation (hematopoeisis) 

Renal ___ provides cytokine signaling for RBC maturation and release from bone marrow 

dietary iron, folate, B12

Renal EPO provides cytokine signaling for RBC maturation and release from bone marrow 

4

1. dietary iron is absorbed in the ____

1. dietary iron is absorbed in the duodenum 

5

2. Fe 2+ may be stored in the ___ bound with apoferritin to produce the storage form ___ 

2. Fe 2+ may be stored in the enterocyte bound with apoferritin to produce the storage form ferritin 

6

3. Fe 2+ released from basolateral enterocyte surface via ____

3. Fe 2+ released from basolateral enterocyte surface via ferroportin 1

7

4. Fe 2+ is oxidized to Fe 3+ by ___

4. Fe 2+ is oxidized to Fe 3+ by ferroxidase

8

5. Fe3+ is bound and transported in the blood via ____ to sites of erythropoiesis: ____, and to the ___ where it binds to apoferritin for storage

5. Fe3+ is bound and transported in the blood via transferrin to sites of erythropoiesis: bone marrow, and to the liver where it binds to apoferritin for storage

9

6. When ferritin is filled, hepatocytes produce ___ which feeds back on enteric iron absorption to ____ ferroportin 1 activity 

6. When ferritin is filled, hepatocytes produce hepcidin which feeds back on enteric iron absorption to downregulate ferroportin 1 activity 

10

duodenal iron absorption: ___ mg/day

iron recycling in liver and spleen: ___ mg/day

duodenal iron absorption: 1 mg/day

iron recycling in liver and spleen: 30 mg/day

11

in iron deficiency, what lab findings do you see? 

transferrin saturation ?
ferritin ? 
TIBC ?

decreased transferrin saturation
decereased ferritin 
increased TIBC 

12

___ route is preferred in iron therapy

oral route is preferred in iron therapy

13

__ iron is best absorbed 

ferrous (Fe2+) iron is best absorbed 

14

list the ferrous iron oral drugs and what is co-administered for optimal absorption? 

  • ferrous sulfate
  • ferrous gluconate
  • ferrous fumarate
  • ascorbic acid for optimal absorption

15

when do you give parenteral iron therapy? 

chronic renal failure patients (high iron requirement) 

hemodialysis patients (in combo with EPO) 

 

16

list the parenteral iron formulations 

  • iron dextran - highest risk for type 1 HSN 
  • sodium ferric gluconate complex 
  • iron sucrose 

17

list adverse affects of iron therapy

  • black stool
  • GI
    • nausea 
    • epigastric discomfort
    • abdominal cramps
    • constipation
    • diarrhea

18

what is the presentation of acute iron toxicity? 

  • history of iron ingestion by children 
  • direct GI irritation 
    • acue vomiting 
    • diarrhea
    • abdominal pain
    • mucosal ulceration and bleeding

19

describe the pathogenesis for acute iron toxicity 

  • free iron disrupts critical cellular processes 
    • metabolic acidosis
    • widespread organ toxicity → shock, coma, death
  • abdominal radiographs showing radio-opaque pills in stomach  

20

how do you treat acute iron toxicity? 

  • activated charcoal is NOT effective (does not bind to iron) 
  • supportive care
  • iron chelators:
    • Deferoxamine
    • Deferasirox 

21

contrast deferoxamine and deferasirox 

  • deferoxamine
    • given IV to bind system iron 
    • promotes iron excretion (urine/feces) 
    • moderate & severe iron toxicity 
  • deferasirox 
    • oral 
    • only effective at reducing iron absorption if given within 1 hour of ingestion 
    • used for chronic iron toxicitiy → outpatient iron chelation in transfusion dependent individuals 

22

what can cause chronic iron toxicity? 

  • hemochromatosis 
    • cardiomyopathy
    • bronze diabetes
    • cirrhosis
  • patients requiring frequent blood transfusions (thalassemia major) 

23

desribe B12 absorption 

  • consumed in animal products
  • salivary R binders bind to free B12
  • pancreatic enzymes break up the complex and binds of IF from parietal cells → duodenum
  • IF-cobalamin complex absorbed in terminal ileum 
  • transported bound to glycoproteins as transcobalamin I, II, III 

24

The main storage site of B12 is in the ____ and takes ____ to develop B12 deficiency

The main storage site of B12 is in the liver and takes 5 years to develop B12 deficiency

25

list causes of B12 deficiency

  • insufficient ingestion (strict vegans) 
  • defects in cobalamin absorption 
    • autoimmune disease: prenicious anemia 
    • surgery: gastrectomy, ileal resection 
    • small bowel disease: crohn's, celiac, fish tapeworm infection (diphyllobothrium latum) 
  • Drugs 

26

what drugs cause B12 deficiency? 

  • metformin, neomycin: alter gut flora
  • nitrous oxide anethesia: converts cob(I)alamin to inactive form cob(III)alamin
  • proton pump inhibitors, histamine 2 receptor antagonists: increase gastric pH 

27

describe the clinical presentaiton of vitamin B12 deficiency

  • anemia 
  • neurological symptoms 
    • parethesias 
    • subacute combined degeneration of spinal cord d/t abnormal myelination synthesis
    • prolonged deficiency = irreversible nerve damage
  • skeletal changes
    • suppressed osteoblast activity → osteoporosis 

28

what are the lab studies in B12 deficiency? 

  • megaloblastic macrocytic anemia
  • leukopenia and/or thrombocytopenia 
  • decreased B12
  • +/- antibodies agaist IF 
  • increased homocysteine
  • increased methylmalonate
  • increased methylmalonyl-CoA

29

explain B12 deficiency therapy and its adverse effects

  • must be parenteral and continued for the duration of malabsorption 
  • hydroxycobalamin
    • preferred highly-protein bound form → stays in circulation longer 
  • cyanocobalamin 
  • no adverse effects! 

30

what is the most common nutrient deficiency in USA? 

Folate deficiency