Anemia Flashcards
Anemia is defined as…
a decrease in Hbg and Hct concentrations below the normal range for age and gender
Causes of anemia include:
decreased or impaired RBC production, RBC destruction (hemolysis), blood loss
Erythrocytes have a lifespan of about…
120 days
A decrease in RBC production can be due to…
nutritional deficiencies (e.g. iron, folate, vitamin B12) or it can occur as a complication of another disorder, such as CKD or a malignancy
Signs of iron deficiency anemia can include:
glossitis (an inflamed, sore tongue), koilonychias (thin, concave, spoon-shaped nails) or pica (eating non-foods such as chalk or clay)
Patients with vitamin B12 deficiency can present with neurologic symptoms such as:
peripheral neuropathies, visual disturbances, and/or psychiatric symptoms
The mean corpuscular volume (MCV) reflects the…
size or average volume of RBCs
A low MCV (<80 fL) means that…
the RBCs are smaller than normal (microcytic). Likely due to iron deficiency.
A high MCV (>100 fL) means that…
the RBCs are larger than normal (macrocytic). Likely due to vitamin B12 or folate deficiency
A normal MCV means that…
the RBCs are normal in size. Likely due to acute blood loss, malignancy, CKD, bone marrow failure (aplastic anemia), hemolysis
Iron studies further evaluate microcyctic anemia; these include:
serum iron (bound to transferrin), serum ferritin (iron stores), transferrin saturation, and total iron-binding capacity (amount of transferrin binding sites available to bind or unbound sites)
Causes of iron-deficiency anemia include:
poor dietary intake, blood loss, decreased iron absorption (high gastric pH/PPI use, GI diseases), and/or increased iron requirements (pregnancy, lactation, infants, adolescents)
The CDC recommends low-dose iron supplements equivalent to…
30 mg/day for all pregnant women (vegetarians may also benefit)
Treatment of iron-deficiency anemia includes…
100-200 mg elemental iron per day (taken on an empty stomach). Sustained-release or enteric-coated formulations can cause less GI irritation but are not recommended for initial therapy.
Tx goal in iron-deficiency anemia is a…
1 g/dL increase in Hbg every 2-3 weeks
% elemental iron in oral products (BBW: accidental OD in children-keep away from children)
Ferrous gluconate= 12%; Ferrous sulfate= 20%; Ferrous sulfate, dried= 30%, ferrous fumarate= 33%, carbonyl iron (polysaccharide iron complex, ferric maltol= 100%)
The antidote for iron overdose is…
deferoxamine (Desferal)
A stool softener such as docusate is often recommended to…
prevent iron-induced constipation
ferrous sulfate (FeroSul, Fer-in-Sol)
325 mg (65 mg elemental iron)
ferrous sulfate, dried (Slow Fe, Slow Iron)
160 mg (50 mg elemental iron)
ferrous fumarate
324 mg (106 mg elemental iron)
ferrous gluconate (Ferate)
324 mg (38 mg elemental iron)
ferric maltol (Accrufer)
30 mg (30 mg elemental iron)
carbonyl iron (FerraPlus, Ferralet 90, Iron chews)
90 mg (90 mg elemental iron)
Separate antacids from iron supplements (take iron 2 hours before or 4 after) and avoid…
H2RAs and PPIs (raise gastric pH for up to 24 hours)
Take iron 2 hours before or 4-8 hours after taking…
quinolone and tetracycline antibiotics