Approach to Anemia

Diagnostic Approach

The American College of Physicians defines anemia as a reduction in hemoglobin concentration, red-cell count, or packed cell volume below normal levels 1
Classification by severity is defined as:
- Mild: Hb ≤11.9 g/dl and ≥10 g/dl 1
- Moderate: Hb ≤9.9 and ≥8.0 g/dl 1
- Severe: Hb <8.0 g/dl 1
Initial assessment includes complete blood count (CBC) with indices to characterize anemia and identify other cytopenias, as recommended by the National Comprehensive Cancer Network 2
Visual review of peripheral blood smear is used to confirm RBC size, shape, and color, as recommended by the National Comprehensive Cancer Network 2
Morphologic classification based on mean corpuscular volume (MCV) is used to identify the underlying cause of anemia, including microcytic, normocytic, and macrocytic anemia, as recommended by the National Comprehensive Cancer Network 2

The American Gastroenterological Association recommends oral iron supplementation as first-line therapy for iron deficiency anemia 1
Intravenous iron therapy is indicated when oral iron is not tolerated, malabsorption is present, or rapid repletion is needed, as recommended by the American Gastroenterological Association 1
In patients with inflammatory bowel disease and active inflammation, intravenous iron therapy is recommended, as stated by the American Gastroenterological Association 4

The American College of Gastroenterology recommends treating the underlying inflammatory condition to enhance iron absorption and reduce iron depletion 4
In patients with inflammatory bowel disease and iron deficiency anemia, intravenous iron therapy is recommended, as stated by the American College of Gastroenterology 4
Erythropoiesis-stimulating agents (ESAs) may be considered in specific situations, such as chemotherapy-induced anemia, but are not recommended for mild to moderate anemia with heart disease, as stated by the American College of Cardiology 5

The American Association for the Study of Liver Diseases recommends restrictive red blood cell transfusion strategy (trigger hemoglobin threshold of 7-8 g/dl) in hospitalized patients with coronary heart disease 5
Packed red cell transfusions are indicated when hemoglobin decreases to less than 7.5 g/dl and/or clinical symptoms are present, as recommended by the European Association for the Study of the Liver 7

The Crohn's and Colitis Foundation of America recommends determining whether iron deficiency anemia is due to inadequate intake/absorption or loss of iron through gastrointestinal bleeding 4
Active inflammation should be treated effectively to enhance iron absorption, as recommended by the Crohn's and Colitis Foundation of America 4

The American Heart Association recommends using restrictive red blood cell transfusion strategy (trigger hemoglobin threshold of 7-8 g/dl) in patients with heart disease 5
Erythropoiesis-stimulating agents should be avoided in patients with mild to moderate anemia and congestive heart failure or coronary heart disease, as stated by the American Heart Association 5

The National Comprehensive Cancer Network recommends evaluating for multiple potential causes of anemia, including chemotherapy effects, nutritional deficiencies, and bone marrow infiltration 2
Erythropoiesis-stimulating agents may be considered for chemotherapy-induced anemia with appropriate hemoglobin thresholds, as recommended by the National Comprehensive Cancer Network 1

The American Society of Hematology recommends repeat hemoglobin measurement after 4 weeks of treatment for iron deficiency anemia 1
Iron treatment should be continued for 2-3 months after correction of anemia to replenish stores, as recommended by the American Society of Hematology 1