Anemia Flashcards
What makes up hemoglobin?
- Hemoglobin is found in lab value by spinning down blood and separating from plastma. Formed elementts (45% RBC) also includes buffy coat is made up of WBC, PLT
- Hemoglobin is composed of :
- heme- iron and porphyrin ring
- globin- 2 alpha, 2 beta globins to make tetrameric hemoglobin
What are reticulocytes?
- “baby” RBC, look like RBC but it still has RNA/ribosomes and are still making Hgb
- not quite mature or finished making hgb
- useful for differential diagnosis of various anemias
- Circulate for 1 day (under normal conditions)
- 1% blood are reticulocytes (under normal conditions)
What are erythrocytes
- Mature RBC. No more hemoglobin synthesis
- Circulate for 100 days and recycled via the spleen
How does the spleen recycle RBC?
- Mostly get recycled in the spleen
- RBC comes in one end, has to go through sinusoidal capillary in order to get into red pulp. At other side of red pulp, squeezes through endothelial gap
- squeezes through endothelial cap to get into sinusoidal capillary(unclear on this exact mechanism, can’t find extra resources). BUT If RBC can’t make it through the gap( rbc is too old/stiff) and stays in red pulp, macrophage in the “red pulp” in the spleen will eat the RBC
- this is how we clear most of RBC (in spleen)
- quicker RBC can get out of pulp and into sinusoid will survive. old ones will get eaten
- Macrophages can also pluck out pieces of the RBC without destorying the whole thing
What is the trigger for making more RBC?
erythropoietin
- Uncommitted pluripotential stem cell + erythropoietin–> commited proerythroblast (committed to eventually become RBC)
What is hypoxia? Hypoxemia?
- Hypoxia is reduced tissue oxygenation
- Hypoxemia is reduced partial pressure of oxygen in the blood
What does anemia result in, in relation to hypoxia and hypoxemia?
anemia results in hypoxia without hypoxemia
What is hypoxemia without hypoxia
polycythemia
What are some manifestations of anemia?
More or less what garman said about picture:
- Weakness/fatigue
- pallor
- increased RR, depth
Compensatory mechanisms from tissue hypoxia
- pump more blood (CV)
- increase SV
- Increase HR
- Capillary dilation
- kidney increases blood volume
- further increases CO
- little anemia is fine
- problem if very anemic, will get HUGE increase CO and then you run into high output cardiac failure (blood moving so fast that it doesn’t have time to unload oxygen at tissues)
- also get heart murmurs with High output cardiac failure
- this is seen at HCT in 20s
- further increase in CO won’t help because of decreased time in capillaries
- we need to make more RBC to fix the problem!! (kidney will kick in with more erythropoitin and signal body to make RBC)

What does tissue hypoxia in anemia cause?
- Ischemia
- claudication (muscle)
- weakeness, increase fatigue
- pallor (skin /mucous membrane)
- Respriatory: increase RR, depth, “exertional dyspnea”
- CNS - dizziness, faiting, lethargy
- Liver
- fatty changes. fatty changes also occur in heart and kidney

What are some compensatory mechanisms from anemia?
- Increase oxygen demands for work of heart
- heart (angina)
- increase erythropoietin
- stimulated bone marrow
- CV changes
- increase HR
- Capillary dilation
- increase SV
- Hyperdynamic ciruclation
- cardiac murmurs
- high-output cardiac failure
- Hyperdynamic ciruclation
- renal (he said this should be by increase erythropoietin)
- increase Renin-aldosterone response
- increase salt and h2o retention
- increase ECF (furhter causing hyperdynamic circualtion)
- Increase DPG in cells
- increase release of oxygen from hemoglobin in tissues

Will increasing CO in a severely anemic patient help with hypoxia?
No, need more RBC!
Blood already doesn’t have enough time to unload o2, so increasing CO does not help the situation
What is physio process behind stimulating RBC production?
Role of erythropoietin in regulation of erythropoiesis. Decreased arterial oxygen levels stimulate production of erythropoietin, which in turn stimulates red cell production and expansion of the erythron. The increase in red cells frequently corrects the problem of low oxygen levels (hypoxia). The restoration to normal oxygen level alerts the kidney to stop producing erythropoietin

What are 4 main categories of anemia?
- Macrocytic
- Microcytic
- Normocytic-normochromic from decreased erythrocyte production
- Normocytic-normochromic from increased erythrocyte turnover
What is macrocytic anemia? Causes?
- MCV >100 fL (megaloblastic anemia)
- problem with DNA syntehiss
- DNA syntehsis is slow d/t decreased amt of nucleotides but cell continues growing while it’s waiting on DNA to replicate
ex:
- B12 deficiency- lack of IF degrades the B12 before it can be absorbed in the GI tract
- Folate Deficiency- common in alcoholics, processing alcohol depeltes folate
- Any drug (ie chemo drugs) that inhibit DNA synthesis
What is microcytic anemia? Causes?
- MCV <80 fL
- problem with hemoglobin synthesis
- results in a small, pale cell (hypochromic)
Causes:
- Iron deficiency- usually results from blood loss (adults) or nutritional deficiency (children)
-
Thalassemia- genetic defect in alpha globin or beta globin
- therefore can’t make the tetrameric heme we need ofr hemoglobin
What is normocytic-normochromic anemai caused by decreased in erythrocyte production? RI? Causes?
Normal size RBC, normal color. Just not making enough RBC. Low RI
Causes:
- Anemia of chronic renal disease (EPO deficiency)
- anemia of chronic disease- attempt to keep iron away from bugs (also microcytic)
-
Sideroblastic anemia- defect in iron handling–> dysfunctional hemoglobin (also microcytic). Can’t put iron in porphyrin ring
- genetic
- acquired- lead poisoning
- Myelofibrosis- marrow replaced with fibrosis (w/pancytopenia)
-
Aplastic anemia- marrow repalced with fat
- gneetic- congenital aplastic anemia (fanconi anemia)
- Acquired- due to bone marrow toxicity, typically from drugs
What causes anemia of chronic disease?
- Heme is important in many enzymes (anyone that processees oxygen)
- Bacteria also need iron for much of the same reason (enzymatic processes)
- during anemia of chronic disease, our immune system (macrophages) keep iron away from bacteria
- keep iron locked away in macrophages
- looks iron deficient but different
- iron defiicent= give iron and fix
- anemia of chronic disease- iron does NOT fix problem
- occurs in infectious and chronic dx
normocytic-normochromic anemia d/e decreased erythroyte produciton (low RI)
What is sideroblastic anemia?
Defect in iron handling–> dysfuncitonal hemoglobin ( also microcytic)
- have iron, have porphyrin ring, but can’t put iron in porphyrin ring
- genetic
- acquired- lead poisoning
- lead looks like iron, enzyme picks up lead
- lead binds irreversibly
- now enzyme that puts iron in porphyrin, is blocked by the lead
normocytic-normochromic anemia d/e decreased erythroyte produciton (low RI)
What is myelofibrosis?
- marrow replaced with fibrosis (seen w/ pancytopenia- loosing bone marrow)
- normocytic-normochromic anemia d/e decreased erythroyte produciton (low RI)
What is aplastic anemia
- marrow repalced with fat (w/pancytopenia)
- genetic- congenital aplastic anemia (fanconi anemia)
- acquired- due to bone marrow toxicity, typically from drugs
normocytic-normochromic anemia d/e decreased erythroyte produciton (low RI)
What are causes of normocytic-normochromic anemia from increased erythrocyte turnover? RI?
- Normal cell size, nomal color. HIGH RI
Causes:
- Hemolytic anemia
- membrane defect
- metabolic defect
- hemoglobin defect
- hemolytic disease of the newborn
- hemorrhagic anemia
What is reticulocyte index?
- Reticulocyte count corrected for degree of anemia
- the more anemic someone it, the more we expect them to make RBC
- Under normal conditions, reticulocytes exist for 1 day, BUT if someone is anemic, the reticulocytes will be released earlier and they’ll circulate longer as reticulocytes
- no anemia- RI should be 0.5-2%
- anemia- RI should be >2%
- Equation (unsure if we actually need to know)
- RI= [(reticulocyte count * HCT)/ normal HCT (45%)]/ day as reticulocyte
HCT % and days spent as reticulocyte?
- 36-45= 1 day as reticulocyte
- 26-35= 1.5 days as reticulocyte
- 16-25= 2 days as reticulocyte
- <15= 2.5 days as reticulocyte












