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
Take iron 60 minutes after oral ibandronate or 30 minutes after…
alendronate/risedronate
Separate iron by 2-4 hours from…
cefdinir, dolutegravir, levothyroxine, levodopa, methyldopa
Giving iron with 200 mg vitamin C may…
increase iron aborption
IV iron increases Hgb faster than oral iron, and decreases GI issues with PO administration. The total dose needed to replenish iron stores…
(eg. 1000 mg) can be provided in one infusion if needed.
Due to the risk of severe adverse reactions, as well as the cost of IV therapy, IV iron is typically restricted to the following patients:
- CKD on hemodialysis (most common)
- CKD receiving erythropoiesis-stimulating agents (ESAs)
- Unable to tolerate PO iron or failure or PO therapy
- Losing iron too fast for oral replacement
- As an alternative when blood transfusions are not accepted by the patient (e.g for religious reasons)
Iron dextran complex (INFeD) requires…
a test dose before giving full first dose due to anaphylaxis risk
All IV iron products carry a risk for…
hypersensitivity reactions (including anaphylaxis)
To reduce the risk of hypotension, give IV iron products by…
slow IV injection or infusion
Iron dextran and ferumoxytol have a warning of…
anaphylactic rxns
Ferric pyrophosphate citrate (Triferic) is only indicated for iron replacement in patients with…
hemodialysis-dependent CKD; it should be added to the bicarbonate concentrate of the hemodialysate for patients receiving HD
Pernicious anemia is the common cause of vitamin B12 deficiency and occurs due to…
a lack of intrinsic factor which is required for adequate vitamin B12 absorption in the small intestine
Pernicious anemia can be diagnosed using the…
Schilling test and requires lifelong parenteral vitamin B12 replacement
Long-term use (≥2 years) of metformin, H2RAs or PPIs can…
decrease the absorption of vitamin B12
Folic acid deficiency causes…
- ulcerations of the tongue and oral mucosa
- changes to skin, hair, and fingernail pigmentation
Since vitamin B12 is required for enzyme rxns involving methylmalonic acid and homocysteine…
they build up when vitamin B12 is deficient
Initial treatment of vitamin B12 deficiency typically involves…
vitamin B12 injections to bypass absorption barriers, followed by oral supplements (if appropriate)
Cyanocobalamin (vitamin B12); B-12 Compliance, Physicians EZ Use B-12)
Give IM or deep SC: 100-1,000 mcg daily/weekly/monthly
Oral/SL: 1,000-2000 mcg daily
Cyanocobalamin (Nascobal)
Nasal solution (give 500 mcg in one nostril once weekly)
Cyanocobalamin CIs
Allergy to cobalt or vitamin B12 (an intradermal test dose is recommended for any patient suspected of vitamin B12 sensitivity before use)
Cyanocobalamin CIs
Allergy to cobalt or vitamin B12 (an intradermal test dose is recommended for any patient suspected of vitamin B12 sensitivity before use)
Warnings: IV products may contain Al (which can accumulate and cause CNS and bone toxicity if kidney function is impaired) or benzyl alcohol (which can cause fatal toxicity and “gasping syndrome” in neonates)
Folic acid, folate, vitamin B9
Give 0.4-1 mg daily.
Warnings: IV products may contain Al (which can accumulate and cause CNS and bone toxicity if kidney function is impaired) or benzyl alcohol (which can cause fatal toxicity and “gasping syndrome” in neonates)
Side effects: bronchospasm, flushing, rash, pruritus, malaise (all rare)
Folic acid can decrease the serum [ ] of…
fosphenytoin, phenytoin, primidone, phenobarbital
Anemia of CKD is caused by…
a deficiency of erythropoietin (EPO)
Anemia of CKD is treated with…
- Iron therapy
- ESAs
The KDIGO guidelines recommend iron therapy in both non-HD and HD patients if…
TSAT is ≤30% and ferritin levels are ≤500 ng/mL
The KDOQI guidelines recommend iron therapy if…
TSA is ≤20% and ferritin levels are ≤100 ng/mL in non-HD patients and ≤200 ng/mL in HD patients
ESA BBW (use lowest effective dose. Start when Hbg<10 g/dL)
Increased risk of death, MI, stroke, VTE, thrombosis of vascular access. CKD: increased risk of death, serious CV events, and stroke when Hbg level is > 11 g/dL
Decrease or interrupt ESA dose when Hgb…
approaches or exceeds 11 g/dL (CKD on HD), or > 10 g/dL (CKD not on HD)
ESA Warnings and S/Es
Warnings: Hypertension, seizures, serious allergic rxns, serious skin reactions (SJS/TEN).
S/Es: arthralgia/bone pain, fever, headache, rash, N/V, cough, dyspnea, edema, injection site pain, dizziness
ESA CIs
uncontrolled HTN, pure red cell aplasia (PRCA) that begins after tx. Epoetin alfa: multidose vials contain benzyl alcohol (CI in neonates, infants, pregnancy and lactation)
Darbepoetin’s half-life is 3 times longer than epoetin and it can be given…
it can be given weekly, instead of 3x/week
ESA Counseling
Store in fridge; do not shake; rotate injection sites
DVT prophylaxis is recommended when giving epoetin alfa…
before surgery (perisurgery)
Aplastic anemia (AA) occurs when…
the bone marrow fails to make enough RBCs, WBCs, and platelets (can be caused by drugs, infectious diseases, hereditary conditions or autoimmune disorders)
Patients with AA are at risk for…
life-threatening infections or bleeding
Treatment for AA can include…
- immunosuppressants
- eltrombopag (Promacta) if unresponsive to immunosuppressive therapy; it increases platelets
- blood transfusions or a stem cell transplant
Hemolytic anemia develops when RBCs are destroyed and removed from the bloodstream before their normal lifespan of 120 days. It can be…
- acquired (e.g. drug-induced or associated with an immune disorder) OR
- inherited (e.g. sickle cell disease, G6PD deficiency)
A direct Coombs test can be used to detect for acquired (eg. drug-induced). If positive, d/c drugs including…
penicillins, cephalosporins, isoniazid, rifampin, levodopa, methyldopa, cisplatin and other Pl-based drugs, quinidine, quinine, and ribavirin
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked inherited disorder. G6PD protects RBCs from…
harmful substances (reactive oxygen species)
Risk factors that increased the risk of hemolysis in a patient with G6PD includes..
Infections, certain foods (eg. fava beans), severe stress, and certain drugs
The following drugs should be avoided in patients with G6PD deficiency…
chloroquine, primaquine, dapsone, nitrofurantoin, sulfonamides, methylene blue, probenecid, rasburicase
