1.2 + 1.3 highlights pt 2 Flashcards
Anemias, etc
1) About 10% of the avg intake of 10/15mg iron/ day is absorbed in the stomach, ________, and upper _________under acidic conditions.
2) Absorbed iron is released into blood > picked up by transferrin (iron transport protein) > delivered to body and stored in the ______
1) duodenum; jejunum
2) liver
1) Dietary iron present as _______is efficiently absorbed (10–20%) but __________iron less so (1–5%), largely because of interference by phosphates, tannins, and other food constituents.
2) Most of the Fe adults have in their body (3-4 g) is in ____; the rest is stored in the form of ferritin and __________
1) heme; nonheme
2) Hgb; hemosiderin
The RDA of iron is based on an individual’s ___ and _______.
age and sex
Ferroportin is the major iron transporter from the diet across the intestinal lumen; what does it also do?
Also facilitates the transport of iron to apotransferrin in macrophages for delivery to erythroid progenitor cells prepared to synthesize hemoglobin
Hepcidin:
1) What does it do?
2) When is more of it produced?
1) Negatively regulates iron transport by promoting the degradation of ferroportin
2) During inflammation (positive acute phase reactant)
Iron deficiency anemia:
1) What type is it?
2) The most important cause of iron deficiency anemia in adults is chronic blood loss, especially ___________ and __________ blood loss.
1) Microcytic anemia
2) menstrual; GI
Iron deficiency anemia:
1) ___________ blood loss plays a major role in iron metabolism.
2) Women with ____________ will almost always become iron deficient without iron supplementation.
1) Menstrual
2) menorrhagia
Iron defic. anemia:
1) In general, iron metabolism is balanced between ________ of 1 mg/day and _______ of 1 mg/day.
2) What 2 things upset the iron balance, since requirements increase to 2–5 mg of iron per day?
3) Why can’t normal dietary iron supply these requirements?
1) absorption; loss
2) Pregnancy and lactation
3) Medicinal iron supplementation is needed during pregnancy and lactation (also menorrhagia).
Iron defic. anemia:
1) Decreased iron absorption can also cause iron deficiency; give 3 examples
2) Give another reason for this condition
1) Celiac, Gastric resection or jejunal bypass surgery
Zinc deficiency
2) High-intensity athletics
Differentiate between heme iron and nonheme iron
1) From animal sources = heme
2) From plant sources = nonheme
What are some weird Sx of iron deficiency anemia?
1) Pica: craving for nonfood items (clay/dirt, rocks, chalk, paper, etc.); unknown mechanism
a) Pagophagia: craving for ice; esp. common and specific for iron-deficiency (very specific to this type of anemia)
3) Restless leg syndrome (RLS)
4) Skin/mucosal changes:
Plummer-Vinson Syndrome can result from what type of anemia?
Iron deficiency
Reticulocyte count is inappropriately _____ with iron deficiency anemia
low
1) Ferritin is a measure of what?
2) In someone who is anemic, a ferritin level _____ng/mL almost always indicates iron deficiency
3) Even without anemia, a ferritin value _______ ng/mL (in the absence of scurvy) is a highly reliable indicator of reduced iron stores.
(know these numbers)
1) total body iron stores
2) <30
3) <12
True or false: normal/elevated ferritin does not exclude iron deficiency. Explain
True; Levels may rise in response to inflammation (positive acute phase reactant) or other stimuli
As iron deficiency progresses:
1) __________ stores are low
2) ____________ values decline to <30mcg/dL (low)
3) Transferrin (Tf) / Total iron binding capacity (TIBC) levels do what to compensate?
4) What do all these things lead to?
1) Ferritin stores are low
2) Serum iron
3) Rise to compensate (high)
4) Low Transferrin saturation (TSAT) (<15%)
Increased transferrin/TIBC with low serum iron leads to what?
Low transferrin saturation
Iron Deficiency Anemia: Describe what the Peripheral Smear looks like
1) As the MCV falls, the blood smear shows hypochromic microcytic RBCs
2) With further progression, anisocytosis (variation in size) and poikilocytosis (variation in shape) develop.
3) Severe will produce a bizarre peripheral blood smear
Give 3 examples of peripheral smear results with severe iron def. anemia
1) Severely hypochromic cells
2) Target cells (bulls-eye appearance)
3) Pencil-shaped or cigar-shaped cells
Iron def. Tx:
1) Oral iron: Most appropriate form is _________ (allows for dose titration to minimize side effects; may cause tooth discoloration) or ______ containing ferrous salts2
2) What is a common Tx and its dose? List 2 side effects
(know this dose)
1) liquid; tablet
2) Ferrous sulfate, 325 mg (tableta) PO once daily (QD) or every other dayb (QOD) on an empty stomach
-nausea, constipation
Oral iron:
1) Ideally avoid taking with food, and especially avoid taking with __________ (e.g., milk)
2) _________ acidity helps with absorption (e.g., avoid taking with antacids)
3) Taking with_____________ or ____________ may increase absorption (varying efficacy results, under study)
1) Calcium
-taking with food reduces side effects but also iron absorption
2) Gastric
3) Vit. C (ascorbic acid) or orange juice
Oral iron for iron def. anemia
1) Duration of therapy: continue treatment for ________ months after restoration of normal hematologic values to replenish iron stores.
2) What is the most common reason for failure of response?
3) Give 3 other reasons for failure of Tx
1) 3–6
2) Noncompliance
3) Poor iron absorption, Incorrect diagnosis, underlying disease
Potential indications for IV iron include what?
1) Intolerance of or refractoriness to oral
2) GI disease
3) Continued blood loss (ex: dialysis)
4) Second or third trimesters
5) Severe anemia/ rapid correction
1) What IV formulation makes IV use of iron safer?
2) What is the dose?
3) When can it be dosed?
1) Low-molecular-weight iron dextran
2) 1-1.5 g in most patients
3) Single (total dose) infusion or multiple
