Iron deficiency anemia evaluation

Iron-deficiency anemia in chronic PN patients may be due to underlying clinical conditions and the lack of iron supplementation in PN. Parenteral iron therapy becomes necessary in iron-deficient patients who cannot absorb or tolerate oral iron. Parenteral iron should be used with caution owing to infusion-related adverse effects. A test dose of 25 mg of iron dextran should be administered first, and the patient should be monitored for adverse effects for at least 60 minutes. Intravenous iron dextran then may be added to lipid-free PN at a daily dose of 100 mg until the total iron dose is given. Iron dextran is not compatible with intravenous lipid emulsions at therapeutic doses and can cause oiling out of the emulsion. Other parenteral iron formulations (e.g., iron sucrose and ferric gluconate) have not been evaluated for compounding in PN and should not be added to PN formulations. 

The most common cause of iron deficiency in adults is blood loss. Menstruating women lose about 30 mg of iron with each menstrual period women with heavy menstrual bleeding may lose much more. Thus, many premenopausal women have low iron stores or even iron deficiency. In men and postmenopausal women, the most common site of blood loss is the gastrointestinal tract. Patients with unexplained iron deficiency anemia should be evaluated for occult gastrointestinal bleeding. 

Clinical practice guidelines to guide the appropriate use of erythropoietic agents have been developed (Fig. 124-14). The first step is to evaluate the underlying cause of the anemia and initiate specific therapy as indicated. For example, patients with iron deficiency anemia should receive iron supplementation. Patients with chronic bleeding or hemolysis should not receive erythropoietic therapy, as... 

Mr. Veere s malnourished state was reflected in his admission laboratory profile. The results of hematologic studies were consistent with an iron deficiency anemia complicated by low levels of folic acid and vitamin Bi2, two vitamins that can affect the development of normal red blood cells. His low serum albumin level was caused by insufficient protein intake and a shortage of essential amino acids, which result in a reduced ability to synthesize body proteins. The psychiatrist requested a consultation with a hospital dietician to evaluate the extent of Mr. Veere s marasmus (malnutrition caused by a deficiency of both protein and total calories) as well as his vitamin and mineral deficiencies. 

Cangado RD, Brasil SA, Noronha TG, ChiattoneCS. Evaluation of the efficacy of intravenous iron 111-hydroxide saccharate for treating adult patients with iron deficiency anemia. Rev Assoc Med Bras 2005 51(6) 323-8. 

E. Other tests. Nonspecific laboratory findings that support the diagnosis of lead poisoning include anemia (normocytic or microcytic), and basophilic stippling of erythrocytes, a useful but insensitive clue. Acute high-dose exposure may sometimes be associated with transient azotemia (elevated BUN and serum creatinine) and mild to moderate elevation in serum transaminases. Recently ingested lead paint, glazes, chips, or solid lead objects may be visible on abdominal x-rays. CT or MRI of the brain often reveals cerebral edema in patients with lead encephalopathy. Because iron deficiency increases lead absorption, iron status should be evaluated. 

The etiology of microcytic hypochromic anemias as a class can be ascribed to decreased hemoglobin synthesis. Al has been shown to inhibit hemoglobin synthesis in Friend erythroleukemia cells (Abreo et al. 1990) and in bone marrow cells (Zamen et al. 1992), where it also accumulates. In vitro studies evaluating incorporation of Fe " into heme have identified heme, rather than globin, synthesis as the inhibited pathway in uremia (Moriyama et al. 1975). The most common cause of a fault in heme synthesis leading to microcytic anemia is iron deficiency or lack of availability. Although Al-related anemia is refractory to Fe, the anemia could be caused by an interaction between Al and Fe metabolism. 

The underlying cause of anemia (e.g., blood loss iron, folic acid, or vitamin B12 deficiency or chronic disease) must be determined and used to guide therapy. As discussed previously, patients should be evaluated initially based on laboratory parameters to determine the etiology of the anemia (see Fig. 63-3). Subsequently, the appropriate pharmacologic treatment should be initiated based on the cause of anemia. 

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