Anemia laboratory evaluation

A woman 7 months pregnant with her first child develops anemia. Laboratory evaluation indicates an increased mean cell volume (MVC), hypeisegmented neutrophils, and altered morphology of several other cell types. The most likely underlying cause of this woman s... 

A standard initial laboratory evaluation for anemia includes a complete blood count (evaluation of the serum hemoglobin and hematocrit concentration, white blood cell count, platelets), measurement of the red blood cell count and size, and review of peripheral smear. 

This chapter will provide an overview of anemia. This first section will present definitions and classification systems. A review of basic aspects of erythropoiesis, followed by laboratory evaluation of the anemia patient will then be discussed. The general similarities in the clinical presentation of the anemic patient will be presented in the text. 

Table 32-3 summarizes laboratory results obtained on patients with three different causes of jaundice—hemolytic anemia (a prehepatic cause), hepatitis (a hepatic cause), and obstruction of the common bile duct (a posthepatic cause). Laboratory tests on blood (evaluation of the possibihty of a hemolytic anemia and measurement of prothrombin time) and on semm (eg, electrophoresis of proteins activities of the enzymes ALT, AST, and alkahne phosphatase) are also important in helping to distinguish between prehepatic, hepatic, and posthepatic causes of jaundice. 

TABLE 63-1. Pertinent Laboratory Tests in the Evaluation of Anemia... 

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. 

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. 

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. 

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