Anemia Flashcards
What are the most common signs and symptoms of anemia?
- fatigue, malaise, weakness, headache, dizziness, irritability, difficulty concentrating, pallor, vertigo, trouble breathing upon exertion, palpitations, tachycardia, anorexia, cold intolerance, loss of skin tone
What is the lab definition of anemia?
Hgb <130 g/L for men and <120 g/L for women
What else should be tested for when testing for anemia, esp in older adults?
- occult blood in stool
What is the most common cause of anemia?
- iron deficiency anemia!
What is the clinical presentation iron deficiency anemia?
- dry, rough skin
- brittle nails
- dry, damaged hair or hair loss
- restless leg syndrome
(can have global pain, smooth tongue, reduced salivary flow, pica, pagophagia, cracking at corners of mouth, spooning of fingernails - these are all unlikely unless Hgb < 90 g/L)
What are some common risk factors in developing anemia?
- vegetarian, female, just donated blood, antacid and NSAIDs that block absorption of the iron (NSAIDs also increase risk of GI bleeding)
What does the serum ferritin reflect?
- reflects tissue iron stores (liver, spleen, bone marrow)- acute phase reactant - may be elevated in infection, inflammation and malignancy
What is the normal serum ferritin?
- 20-300 mcg/L
What does the TSAT tell us?
- tells us the amount of iron readily available for use and available to be transferred
- transferrin is the transport protein that takes iron to where it is supposed to go - TIBC is the total amount of seats that is available on the bus for transferrin
(TSAT = serum iron/TIBC)
- it tells us the amount if seats that are being filled- anything less than 14-50% means that the person is fe deficient
What are the lab findings that are consistent with iron deficient anemia? (Hbg, MCV, MCH, MCHC, RDW, reticulocytes, serum ferritin)
Hbg- low MCV-low MCH- low MCHC- low RDW- high reticulocytes- low serum ferritin- low
What are the most common risk factors for IDA?
- adolescents
- menorrhagia
- vegatarians/vegans
- endurance runners, other athletes (increased RBC production, iron loss)
- chronic renal failure patients
- regular blood donors
- surgery
- drugs (ASA/NSAIDs. anticoagulants)
- family history of haematological disorders
What are some sources of heme ironW
- meat, poultry, seafood
- 3x more absorbable vs non-heme iron
- absorption decreased by content of calcium in meals (Ca supps, milk/fairy)
What are some the sources of non-heme iron?
- vegetables, fruits, dried beans, nuts, grains
- absorption increased by gastric acid and ascorbic rich foods, heme iron
What specific food compounds decrease the absorption of iron?
- phytates
- tannins (herbal teas)
- phosphates
- polyphenols (tea/coffee)
- calcium supps
- milk/dairy
- antacids
What is the recommended dose of oral iron for IDA?
- 150-200 mg of elemental Fe/day
- usually divide this dose BID or TID
- give on an empty stomach or at least 2 hours after a meal/1 hour before a meal
- may need to take with meals to decrease the GI SE
What are the main SE associated with oral iron?
- nausea, vomiting, dyspepsia, constipation, diarrhea, dark stools, metallic taste
- – this resolved with time (except for the dark stools)
What are the main DI’s associated with taking iron supplements?
- antacids, PPIs, H2 blockers, cholestyramine, calcium/milk (decrease Fe absorption), levodopa, levothyroxine, quinolones, tetracyclines, bisphoshonates
What is the down side of treating with an SR iron prep?
- slow release past the duodenum may decrease chance for absorption
What is the marketed advantage of using proferrin?
- marketed that it is better absorbed and tolerated- but patients still have SE
- one advantage of thesis that the absorption is not reduced by dairy!
When would we start someone on parenteral iron?
- evidence of iron malabsorption
- intolerance to oral iron
- patient with significant blood loss who refuses blood transfusion and cannot take oral iron
- chronic dialysis patients
- some patients receiving chemotherapy and erythropoesis stimulating agents
How do we calculate the dose of iron for IV?
- dose of iron= weight x (140-hgb)x0.22
- an additional qty of iron to replenish stores should be added (about 600 mg for women and 1000 mg for men)
What are the main side effects associated with IV iron?
- transient side effects: nausea, vomiting, pruritis, headache and flushing. Myalgia and arthralgia, back and chest pain
- some inflammatory mediators are released by the complement system and can cause some facial edema. Some people can get back and chest pain, itchiness without hives and nausea and vomiting
What are the concerns associated with blood transfusions?
- safety and availability
- bloodborne infections, development of autoantibodies, transfusion reactions and iron overload
Who should blood transfusions be given to?
- Hgb < 70-80 g/L
How long should fe treatment be given to patients?
- patients should be treated for 306 months after anemia is resolved to allow for repletion of iron stores and prevent relapse (6-12 months)
- important to monitro for side effects and symptom improvement
- test the person’s ferritin in 3-6 months and do the CBC in 1 months and every 3-6 months
Vitamin B12 is a cofactor that is needed to make ______
nucleic acids
If a person is deficient in vitamin B12 levels, they will likely have high _____ and will have high ______
MMA levels
homocysteine levels
- both high in vitamin B12
In vitamin B12 deficiency, what will you notice with MMA or homocysteine levels?
- both MMA and homocysteine are high
In folate deficiency anemia, what will you notice with MMA or homocysteine levels?
- homocysteine levels are high, but MMA levels are normal
What deficiency will cause neurological symptoms?
low vitamin B12
What is the role of vitamin B12 in the body?
- required along with folic acid in synthesis of DNA, RNA
- essential for maintaining the intergrity of the neurological system
- role in fatty acid synthesis and energy production
- dietary sources: meat, fish, poultry, dairy and fortified cereals
What are the lab findings that are associated with vitamin B12 deficiency anemia? (Hgb, MCV, serum vitamin B12, homocysteine, MMA, WBC, platelets, reticulocyte count)
Hgb: low
MCV: high (macrocytic)
serum vitB12: low
homocysteine: high
MMA: high
WBC, platelets: low(mild)- impaired DNA synthesis
Reticulocytes: low (bone marrow is missing one of the ingredients of production)
What are the signs and symptoms associated with vitamin B12 deficiency anemia?
- numbness and paresthesias, peripheral neuropathy, ataxia, imbalance, decrease vibratory sense, decrease proprioception
- irritability, personality changes, memory impairment, dementia, depression, psychosis
- glossitits, depression, psychosis
- muscle weakness
What are some the main causes of vitamin B12 deficiency?
- inadequate intake (strict vegans, chronic ETOH, elderly)
- malabsorption (pernicious anemia, cobalamin malabsorption- inadequate gastric acid production), Rx acid suppression, overgrowth of bacteria in the bowel that use vitamin B12)
- lack of transport protein
What is pernicious anemia?
- absence of intrinsic factors
What causes pernicious anemia?
- autoimmune destruction of gastric parietal cells
- atrophy of gastric mucosa
- stomach surgery
What are the risk factors associated with pernicious anemia?
- age
- women > men
- europeans of northern african descent, african americans
- – anti-intrinsic factor antibodies -positive in 50%
What drugs are considered to be direct inhibitors of DNA synthesis?
- azathioprine
- hydroxyurea
- zidovudine
- chemotherapy
What drugs are considered to be folate antagonists?
- carbemazepine
- phenytoin, primidone, phenobarbital
- valproic acid
- methotrexate
- pentamadine
- trimethoprim
What drugs are considered to be reduced folate/vitamin B12 absorption?
- excessive ETOH
- amino salicylic acid
- colchicine
- metformin
What is considered to be treatment for vitamin B12 deficient anemia?
- subcut vitamin B12 (cyanocobalamin)
- oral vitamin B12 (cyanocobalamin or methylcobalamin)
- treat early to reduce risk of irreversible neurologic damage
- life time therapy if underlying cause not correlated
When is IM vitamin B12 recommended?
- neurologic symptoms, until resolved, then the person can switch to po
- inadequate evidence for use of po vitamin B12 if severe neurologic impairment
- hospitalized patients
- poor GI absorbance
- unable to take po
- diarrhea/vomiting
- noncompliance
What is the monitoring parameters of anemia?
- reticulocytosis in 305 days (peaks in 7 days)
- hematologic improvements in 5-7 days (normal by 1-2 months)
- hypersegmented PMNs persist for 2 weeks
- vitamin B12 deficiency resolves in 3-4 weeks (improved strength and well being within a few days)
- 6 months or longer required for improvement of neurologic signs/symptoms
What is the role of folic acid in the body?
- production of RNA and DNA
- necessary to form methylcobalamin which converts homocysteine to methionine
- humans are unable to synthesize sufficient folate - dietary sources are needed
- dietary sources of folateL fresh, green leafy veggies, citrus fruits, yeast, mushrooms, dairy products, animal organs
What are some of the causes of folic acid deficiency anemia?
- inadequate intake (elderly, alcoholics, poverty, chronic illness, teenagers)
- decreased absorption (chron’s disease, celiac disease, alcoholism, drugs (phenytoin))
- hyperutilization (pregnancy, hemolytic anemia, malignancy, chronic dialysis)
- alterated metabolism (folate antagonists- methotrexate, trimethoprim, DNA synthesis inhibitors- azathioprine, hydroxyurea)
What are the lab findings associated with folic acid deficiency?
Hbg- low MCV- high (macrocytic) RBC folate- low homocysteine- high MMA- normal vitamin B12- normal
How long should therapy be indoor for folate deficient RBCs to be cleared?
- 4 months
Why is folic acid important to supplement in pregnancy and for how long?
- folic acid supplementation is recommended for at least 1 month prior to conception and until 12 weeks into pregnancy- to decrease occurrence and recurrence of neural tube defects
What is the dose that is recommended for all women of childbearing years
400 mcg - 5 mg daily for if previous offspring with neural tube defects, family history of neural tube defects or taking anticonvulsants
What is erythropoietin?
- hormone that is made by the kidneys- hormone goes to the bone marrow and says for them to make more RBCs
- when the person gets to stage 3 CKD, there is a deficiency in erythropoietin that large hemoglobin of 95-150
- when erythropoietin is given as a treatment, people adapt for the lower hemoglobin
When should IV iron be avoided in giving to a patient?
- should not give it to those people with an active systemic infection
