From the Guidelines
Management of hypochromic anemia with low hemoglobin and elevated RDW typically focuses on iron supplementation, as these findings strongly suggest iron deficiency anemia. The patient's laboratory results show a low hemoglobin level of 8.1 g/dL, which is below the normal range, and an elevated Red Cell Distribution Width (RDW) of 16.6%, indicating variability in red cell size. According to the most recent and highest quality study available 1, oral iron therapy is the first-line treatment for iron deficiency anemia. The recommended treatment includes ferrous sulfate 325 mg (containing 65 mg elemental iron) taken 1-3 times daily between meals with vitamin C to enhance absorption. Alternative formulations such as ferrous gluconate or ferrous fumarate can be used if sulfate is not tolerated. Treatment should continue for 3-6 months to replenish iron stores, even after hemoglobin normalizes. For patients with severe anemia (hemoglobin <7 g/dL), significant symptoms, or poor oral absorption, intravenous iron formulations like iron sucrose or ferric carboxymaltose may be necessary. Concurrent investigation of the underlying cause is essential, including gastrointestinal workup for occult bleeding in adults. Dietary counseling to increase iron-rich foods should complement supplementation. The elevated RDW indicates variability in red cell size (anisocytosis), which occurs in iron deficiency as the body produces smaller cells during iron depletion, while some normal-sized cells remain in circulation, creating this heterogeneity that normalizes with successful treatment. Key points to consider in management include:
- Monitoring of hemoglobin and red cell indices at intervals after treatment initiation
- Further investigation if the hemoglobin and red cell indices cannot be maintained within normal ranges
- Consideration of other potential causes of anemia if iron deficiency is ruled out or if treatment is not effective.
From the Research
Anemia Management
The patient's lab results indicate anemia, characterized by hypochromia, low hemoglobin (8.1 g/dL), and elevated Red Cell Distribution Width (RDW) (16.6%). The management of anemia depends on the underlying cause.
- Iron deficiency anemia is a common cause of microcytic anemia, which is defined as the presence of small, often hypochromic, red blood cells in a peripheral blood smear 2.
- The absence of iron stores in the bone marrow remains the most definitive test for differentiating iron deficiency from other microcytic states 2.
- Measurement of serum ferritin, iron concentration, transferrin saturation, and iron-binding capacity may obviate proceeding to bone marrow evaluation 2.
- A trial of oral iron can be both diagnostic and therapeutic for mild anemia with a hemoglobin of 10.0 g/dL or higher and a mildly low or normal mean corpuscular volume (MCV) 3.
RDW and Anemia Diagnosis
The RDW is a useful indicator of anisocytosis and can be used as a screening index for iron deficiency anemia and other hematologic abnormalities.
- Elevated RDW values are found in anemic patients, with the highest values in iron deficiency anemia, sickle thalassaemia, sickle cell anemia, and beta-thalassaemia trait 4.
- The RDW can discriminate between iron deficiency anemia and thalassaemia trait, with markedly elevated RDW in iron deficiency anemia (mean = 20.7 +/- 3.2) and mildly elevated RDW (mean 15.4 +/- 1.4) in thalassaemia trait 4.
- The sensitivity of RDW for the diagnosis of iron deficiency anemia is 77.1%, and the specificity is 90.6% 5.
Treatment of Iron Deficiency Anemia
The first-line treatment for iron deficiency anemia is oral iron 3.
- New evidence suggests that intermittent dosing is as effective as daily or twice-daily dosing with fewer side effects 3.
- For patients with iron deficiency anemia who cannot tolerate, cannot absorb, or do not respond to oral iron, intravenous iron is preferred 3.
- With contemporary formulations, allergic reactions to intravenous iron are rare 3.