What is the approach to managing a patient with anemia?

Approach to Managing Anemia

The first step in managing anemia is to determine its etiology through systematic laboratory evaluation, followed by targeted treatment based on the specific cause. 1

Diagnostic Approach

Initial Laboratory Evaluation

• Complete blood count with indices
• Peripheral blood smear
• Reticulocyte count
• Iron studies:
  • Serum ferritin (most powerful test for iron deficiency) 1
  • Transferrin saturation (TSAT)
  • Serum iron
• Vitamin B12 and folate levels
• Renal function tests
• Inflammatory markers (CRP, ESR)

Classification Based on Red Cell Indices

Parameter	Iron Deficiency	Thalassemia Trait	Anemia of Chronic Disease
MCV	Low	Very low (<70 fl)	Low/Normal
RDW	High (>14%)	Normal (≤14%)	Normal/Slightly elevated
Ferritin	Low (<30 μg/L)	Normal	Normal/High
TSAT	Low	Normal	Low
RBC count	Normal/Low	Normal/High	Normal/Low

Further Investigations Based on Initial Findings

1. Iron Deficiency Anemia

   • GI evaluation (upper and lower endoscopy) for men and post-menopausal women 2
   • Celiac disease screening (found in 3-5% of IDA cases) 1
   • Gynecological evaluation for pre-menopausal women

2. Microcytic Anemia with Normal Iron Studies

   • Hemoglobinopathy evaluation (hemoglobin electrophoresis)
   • Thalassemia testing

3. Normocytic Anemia

   • Bone marrow examination if myelodysplastic syndrome or other hematologic malignancy suspected
   • Hemolysis workup (LDH, haptoglobin, bilirubin)
   • Renal function assessment

4. Macrocytic Anemia

   • B12 and folate levels
   • Thyroid function tests
   • Liver function tests
   • Alcohol use assessment

Treatment Approach

Iron Deficiency Anemia

1. Oral Iron Therapy (First-line)

   • Ferrous sulfate 200 mg twice daily (containing 35-65 mg elemental iron)
   • Continue for 3 months after hemoglobin normalizes to replenish iron stores 1
   • Monitor hemoglobin weekly until stable, then monthly

2. Parenteral Iron (For specific indications)

   • Indications: intolerance to oral iron, poor response to oral therapy, malabsorption disorders, ongoing blood loss, need for rapid correction 1
   • Options: iron sucrose, ferric carboxymaltose, iron dextran
   • Expected improvement: 1-2 g/dL increase in hemoglobin within 2-4 weeks 1

Vitamin Deficiency Anemia

• Vitamin B12: 1000 μg IM initially, then monthly or oral supplementation 1
• Folate: 1-5 mg daily orally 1

Cancer-Related Anemia

1. Treat Underlying Cause

   • Address tumor-related factors
   • Manage chemotherapy-induced anemia

2. Erythropoiesis-Stimulating Agents (ESAs)

   • Consider in patients receiving chemotherapy with Hb <10 g/dL 2
   • Target Hb level: stable 12 g/dL 2
   • Not recommended for patients not on chemotherapy 2

3. Iron Supplementation

   • For patients with absolute iron deficiency (serum ferritin <100 ng/mL) 2
   • Preferably IV iron for functional iron deficiency

Genetic Disorders of Iron Metabolism

• Management depends on specific disorder
• For X-linked sideroblastic anemia (XLSA): pyridoxine 50-200 mg/day initially, then maintenance 10-100 mg/day 2
• For iron loading conditions: phlebotomy or chelation therapy 2

Blood Transfusion

• Reserve for severe, symptomatic anemia with hemodynamic instability 3
• Target minimum Hb necessary (7-8 g/dL in stable, non-cardiac patients) 2

Follow-up and Monitoring

• Hemoglobin levels: weekly until stable, then monthly
• Iron parameters: regular monitoring during treatment
• Follow-up at three-monthly intervals for one year after normalization 1
• Expected response: 1 g/dL increase in hemoglobin after 4 weeks of oral iron 1

Common Pitfalls to Avoid

• Overlooking functional iron deficiency in inflammatory conditions 1
• Inadequate investigation in elderly patients 1
• Failing to evaluate for other nutrient deficiencies in persistent anemia 1
• Using ESAs in mild to moderate anemia with coronary heart disease 1
• Neglecting to investigate the underlying cause of iron deficiency anemia 2

By following this systematic approach to anemia diagnosis and management, clinicians can effectively identify the underlying cause and implement appropriate treatment strategies to improve patient outcomes and quality of life.