Anemia Flashcards
What is anemia characterized by
A decrease in Hgb resulting in a decrease in O2 carrying capacity of blood that is often a sign of underlying pathology
Acute and Chronic clinical presentations
Acute: cardio symptoms (tachycardia, lightheadedness, breathlessness)
Chronic: fatigue, weakness, HA, vertigo, faintness, sensitivity to cold, loss of skin tone, pallor
Laboratory Evaluation
CBC with RBC indices
retic index
stool sample for occult blood
smear
Iron deficiency anemia
affects over 50 million people world wide; iron is essential for O2 transport;
Iron deficiency anemia results from a a greater demand on stored iron that can be supplied
Common general causes of IDA
inadequate dietary intake inadequate absorption from GI tract increased iron demands blood loss certain diseases
Signs and symptoms of IDA
Koilonychia (spooning of nails)
Angular stomatiis or glositis
Pica
Lab findings for IDA
Low serum iron and ferritin
high TIBC
normal Hgb, Hct, and RBC in early stages, may decrease later on
Non pharm tx for IDA
Dietary supplementation
Heme iron in meat, fish, and poultry absorbed 3x better than nonheme iron in vegetables and dietary supplements
Milk and tea can decrease iron absorption so consume in moderation between meals
Good sources: Total cereal, grape-nuts cereal, instant cream of wheat, instant plain oatmeal, wheat germ, broccoli
Oral Iron therapy
want to maximize absorption in duodenum so we give non enteric coated iron salts
Generally recommended 200 mg elemental iron/day, usually in 2 or 3 divided doses
* dosage strength does not equal how much is actually absorbed *
Ferrous sulfate is MC; 20% elemental iron, 60-65mg of iron, come in 324-325mg tablet (*so need to give 3-4 tablets per day to = 200mg)
AE: GI (discoloration of feces, abd pain, heartburn, N/V/C
if intolerable, take with meals and decrease total daily dose to 110-120mg
Monitoring for Oral Iron therapy
Modest retic count occurs within 7-10 days after initiation of iron therapy
Therapeutic doses of iron lead to an increase in Hgb by 1g/dL q week
Hgb increase of <2g/dL over 3 weeks is unacceptable and should be evaluated further
At least 3-6 months of therapy after anemia is resolved is usually necessary for repletion of iron stores and to avoid relapse
Exceptions to length of tx include: acute bleed (1 month of tx) and Recurrent negative balance (long term tx w/ 30-60mg Fe qd
Parenteral Iron preparations
Iron dextran (50mg Fe/ml): IV or IM by Z track method to minimize staining of skin; may cause pain at injection site, staining of skin, tissue necrosis, atrophy...IV route preferred) Usually require multiple doses AE: arthralgias, myalgias, flushing, malaise, fever, allergic rxns are rare (most likely to occur in hx of allergies, asthma, inflamm disease Give test dose: 25mg IM or IV and observe for 1 hour before administering the remainder of dose if worried about allergic rxn
Vitamin B12 deficiency anemia etiology, s/s and labs
B12 is a water soluble vitamin, obtained by ingestion of meat and dairy products; essential for erythrocyte production and maintaining function of CNS
Etiology: slightly more common in women, increase in incidence with increasing age, d/t inadequate intake, decreased absorption, inadequate utilization
S/s: neuro (peripheral neuropathy, parasthesias, diminished vibration sensation, ataxia, weakness, irritability, dementia, depression; others (glossitis, dysphagia, anorexia)
Labs: MCV >100 (macrocytic), mild leukopenia and thrombocytopenia, retic, B12 and Hct levels usually low
B12 deficiency tx, monitoring, and AE
Tx: oral vitamin B12 therapy, 1-2mg po qday as effective as IM administration
for pernicious anemia (intrinsic factor deficiency) or cobalamin deficency d/t ileal resection, higher doses are needed
Parenteral vitamin B12: start IM or deep subcutaneous; Cyanocobalamin 1000mcg qd for 1 week initially to resolve clinical neuro s/s then decrease to 1000 mcg qweek until Hgb/Hct normalizes, then qmonth
Monitoring: rapid response usually observed, check potassium, retic count increases within 2-5 days, Hgb starts to rise and leukocyte and plt normalize after 1 wk, CBC and B12 usually drawn 1-2 months after start of tx and 3-6 months for surveillance, may need to add iron supplementation
AE: hyperuricemia, hypokalemia, rebound thrombocytosis, fluid retention, anaphylaxis with parenteral route
Folic Acid deficiency anemia etiology, s/s, labs
heat labile vitamin necessary for production of nucleic acids, proteins, amino acids, purines, and thymine DNA and RNA; humans get it from diet
Major causes: inadequate intake, decreased absorption, hyperutilization (pregnancy), inadequate utilization
Medications: Directly inhibit DNA synthesis, Folate antagonists (trimethoprim), Mechanism Unclear (phenytoin, phenobarbital)
S/s: glossitis, dysphagia, anorexia (same as B12 without neuro symptoms)
Lab findings: similar to B12 deficiency except B12 levels are normal; decrease serum and RBC folate also seen
Folic Acid deficiency anemia tx, monitoring
tx: Folic Acid 1mg PO qd x 4 months (if underlying cause is identified and corrected)
low dose folate tx can be used for anticonvulsant induced anemia to avoid d/c of the AED
folate supplementation PRIOR to conception and during pregnany
monitoring: sx improvement often noted daily, reticulocytosis occurs within 2-3 days, peaks within a week,
Hct begins to rise within 2 weeks and returns to normal within 2 months
MCV will initially increase, but gradually decrease d/t normal
