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anemia
a hematologic sign of another disease process occuring within the body which results in heightened destruction of RBCs, a dec prod of RBCs, or an acute loss of RBCs
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immature erythrocytes
reticulocytes
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hormone released when o2 concentrations decrease
EPO, kidney stimulates the release
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EPO signals stem cells within bone marrow to produce reticulocytes and is responsible for:
stimulating cell differentiation, increasing amt of reticulocytes released from bone marrow, and signaling an increase in hemoglobin production
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iron is transported to bone marrow by:
transferrin, excess iron known as ferritin or hemosiderin in the liver, spleen, and bone marrow
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erythrocyte dev also requires additional cofactros including:
vitamin B12 and folate
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erythrocytes remain in circulation approx
120 days, then undergo destruction and recycling by macrophages
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Hemoglobin (Hb) lab value, what it is and normal values for men and women?
- measures the ability of the RBC to carry oxygen
- Men: 13-18g/dL
- Women: 12-16 g/dL, factors that can increase Hb:smoker, higher alt, diff ethnic groups
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Hematocrit, what is and normal ranges
- percentage of RBCs to TOTAL blood volume,
- Men: 41-53%
- Women: 36-46%
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Anemia is defined as a decrease in (___ and ___) below normal ranges
hemoglobin OR hematocrit
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mean corpuscular volume (MCV)
average RBC volume, normal range:80-100fL
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types of anemias based on MCV
microcytic, macrocytic, or normocytic
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microcytic anemia
<80 fL, RBCs are small
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examples of microcytic anemia
iron deficiency anemia (IDA), thalassemia, anemia of chronic disease, sideroblastic
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normocytic anemia
80-100fL, normal sized cells
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examples of normocytic anemia
acute blood loss, hemolytic anemia, anemia of chronic disease, anemia of chronic kidney disease, mixed anemia
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macrocytic anemia
>100fL, large cells
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examples of macrocytic anemia
vitamin B12 deficiency anemia, folate deficiency anemia
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mean corpuscular hemoglobin (MCH)
- Hb/RBC count
- normal: 26-34 pg
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mean corpuscular hemoglobin concentrations (MCHC)
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red blood cell distribution width (RDW)
- variance btwn RBC sizes within a given sample
- normal: 11-16&
- can be a helpful measure to look at in the case of mixed anemias (greatly increased)
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reticulocyte count
measurement of new RBC production, used to calc reticulocyte production index (RPI) to determine if bone marrow is responding adeq to the RBC needs of the body
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RPI value indicated an inadequate response of the bone marrow
RPI<2
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decreased Hb/Hct with normal RPI indicates:
blood loss or a hemolytic anemia
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decreased Hb/Hct with decreased RPID
indicates anemia by another cause
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acute onset of anemia
severe cardiovascular and respiratory symptoms incuding tachycardia, lightheadedness, shortness of breath, decreased blood pressure
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chronic onset of anemia
wide variety of symptoms including, but not limited to HA, dizziness, weakness, feeling tired, and senstivity to cold
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prevalence of IDA
- men-2%
- women-9-12%
- african amer/hisp women-approximately 20%
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causes of IDA
- abnormal iron balance: dec intake, inade abs or dietary iron, blood loss(i.e.menstruation)
- increased physiologic need: prenancy/lactation, infants, adolescence
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serum iron
- conc of iron bound to transferrin
- normal male: 50-160 mcg/dL
- female: 40-150 mcg/dL,
- in IDA, serum iron may be decreased or normal
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total iron binding capacity (TIBC)
measure of the ability of transferrin to bind additional iron, normal range: 250-450 mcg/dL, can be used to differentiate diagnosis
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TIBC >400 mcg/dL
likely IDA
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TIBC <200 mcg/dL
likely inflammatory disorder and not IDA
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transferrin saturation
- shows the amt of iron avail for the prod of RBC
- normal: 20-50%
- in IDA, transferring sat <=15%
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ferritin
- meas of the amt of iron currently being stored in the body
- normal male: 15-200ng/ml
- female: 12-150 ng/ml
- in IDA, ferritin is ALWAYS decreased
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signs and sx specific to IDA
- PICA (cravings for nonfood items)and Pagophagia (cravings for ice)
- Koilonychia (spooning of the nails), seen more in elderly
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typical starting dose of oral iron supplement
first line ror IDA, 200 mg elemental iron d, 2-3 divided doses, increasing freq can improve tolerability, best on empty stomach at least one hour b4 meals but food dec GI upset, dk colored stools
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meds that dec iron abs
alum. mg, and calc containing antacids, H2 antag, PPIs, and tetracycline
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common meds whose abs is decreased by iron:
levodopa, levothyroxine, fluroquinolones, and tetracycline
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monitoring for oral iron preparations
Hb should increase 1-2g/dL weekly with 200 mg elemental dose, tx for 3-6mo post resolution of IDA to re-build iron stores, pts requiring long-term therapy often req d small daily doses (30-60mg pf elemental iron)
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parenteral iron preparations, when and which ones
pt unable to correctly absorb iron from the Gi tract, pt has a hx of long-term noncompliance w oral replacement therapy, and/or pt is intolerant of oral replacement therapy, sodium ferric gluconate (ferrlecit), iron sucrose (venofer), iron dextran-black box for anaphylaxis
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ways to give IV iron
as multiple slow inj of undiil soln (not to exceed 50 mg, 1 mL per minute) dose limited to 2mL (100mg) daily in adults, or IM via Z-tract inj technique to minimize staining, max IM dose:2 ML (100mg) d in adults or total dose inf (non fda-approved), dilute in NS or D5w and give as a total dose inf over 4-6 hours
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test dose of InFed
25 mg (0.5mL)IM or IV, over 30 seconds
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test dose of DexFerrum
25 mg (0.5mL)IM or IV, over 5 minutes
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test dose of total dose infusion soln
diluted total dose inf soln 5-10 min inf of the diluted total dose soln, if no adverse effect/anapylaxis after 1 hour, then remainder of dose may be given
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AEs of parenteral iron
- imm: pain at inf site, discoloration/staining at inf site, allergic rxns/anaphylaxis
- delayed: joint pain, muscle pain, fever, HA, dizziness, N&V
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monitoring of parenteral iron
increased liver fxn tests, ferritin>800ng/mL, transferrin saturation >50%, monitor Hb, Hct weekly, iron and ferritin monthly
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