What is the plan of care for a patient with normocytic anemia?

Management of Elevated RBC Count with Microcytosis

The primary plan of care for this 52-year-old female with elevated RBC count (5.45 million/μL), low MCH (26.4 pg), and low MCHC (31.2 g/dL) is to immediately check serum ferritin to distinguish between thalassemia trait and iron deficiency, and critically, do NOT initiate empiric iron therapy before confirming iron deficiency, as this can cause iron overload in thalassemia patients. 1

Immediate Diagnostic Workup

The combination of elevated RBC count with microcytosis (indicated by low MCH and MCHC) creates a distinctive pattern where thalassemia trait is the primary consideration, representing the body's compensatory response to ineffective hemoglobin production. 1

Essential First-Line Testing

• Check serum ferritin first as the most specific test—levels <30 μg/L indicate true iron deficiency, while normal or elevated levels point toward thalassemia trait. 1
• Obtain complete blood count with red cell indices including MCV and RDW to further characterize the microcytosis. 2
• Measure serum iron, total iron-binding capacity (TIBC), and transferrin saturation to assess iron availability for hemoglobin synthesis. 2
• Check reticulocyte count to evaluate bone marrow response and rule out hemolysis. 2, 3

Key Distinguishing Features to Assess

• Thalassemia trait typically shows microcytosis disproportionate to anemia (MCV often 60-70 fL) with elevated or normal RBC count (often >5.0 million/μL), which matches this patient's presentation. 1
• Iron deficiency shows elevated RDW (>14.0%) reflecting heterogeneous cell sizes and low serum ferritin (<30 μg/L). 1
• Examine peripheral blood smear for red cell morphology—normocytic normochromic appearance suggests anemia of chronic disease or other causes, while hypochromic microcytic cells suggest iron deficiency or thalassemia. 2

Management Based on Ferritin Results

If Ferritin <30 μg/L (Iron Deficiency Confirmed)

• Investigate the source of blood loss, particularly gastrointestinal in post-menopausal women, as malignancy must be excluded. 1
• Perform stool guaiac test for occult gastrointestinal bleeding. 2
• Consider evaluation for other sources of chronic blood loss including menstrual history (though less likely in a 52-year-old who may be perimenopausal). 2
• Treat with oral ferrous sulfate 200 mg three times daily for at least 3 months after anemia correction. 1
• Monitor hemoglobin and red cell indices at 3-month intervals for one year, then annually. 1

If Ferritin ≥30 μg/L (Thalassemia Trait Likely)

• Proceed with hemoglobin electrophoresis to confirm thalassemia trait, which will show elevated HbA2 (>3.5%) in beta-thalassemia trait or abnormal hemoglobin patterns. 4
• Provide genetic counseling and offer partner testing if reproductive planning is relevant. 1
• No specific treatment is required for thalassemia trait as it is typically asymptomatic or causes only mild anemia. 1
• Educate patient that this is a benign condition that does not require iron supplementation. 1

Critical Management Pitfalls to Avoid

• Never initiate empiric iron therapy before confirming iron deficiency in patients with elevated RBC count and microcytosis, as this can cause iron overload in thalassemia trait patients. 1
• Assuming all microcytosis is iron deficiency leads to inappropriate iron supplementation in thalassemia patients, potentially causing iron overload. 1
• Do not transfuse unless hemoglobin drops to symptomatic levels (typically <7-8 g/dL in stable patients). 2
• Failing to provide genetic counseling once thalassemia trait is confirmed is a critical oversight, as family screening and genetic counseling are essential, particularly for reproductive planning. 1

Additional Workup if Initial Testing Inconclusive

• Evaluate for anemia of chronic disease by checking inflammatory markers (ESR, CRP) and assessing for underlying chronic conditions (renal disease, inflammatory disorders, malignancy). 2, 5
• Check serum creatinine and estimated GFR to evaluate for chronic kidney disease, which causes normocytic anemia. 2
• Consider vitamin B12 and folate levels if macrocytosis develops or if other causes remain unclear. 2, 6
• Evaluate thyroid function, as hypothyroidism can contribute to anemia. 2

Monitoring Strategy

• For confirmed iron deficiency: Monitor hemoglobin weekly until stable, then every 3 months during iron replacement, then at 3-month intervals for one year after correction. 2, 1
• For confirmed thalassemia trait: No routine monitoring required unless symptoms develop; provide one-time genetic counseling and family screening recommendations. 1
• Reassess if anemia worsens or new symptoms develop, as this may indicate an additional underlying process. 2