What is the approach to managing anemia?

Approach to Managing Anemia

All patients with anemia should receive appropriate diagnostic evaluation to identify the underlying cause, followed by targeted treatment with iron supplementation as first-line therapy for iron deficiency anemia, continuing for three months after correction of anemia to replenish iron stores. 1

Diagnostic Evaluation

Initial Assessment

• Complete blood count with red cell indices
• Ferritin level (< 15 μg/dL indicates iron deficiency)
• MCV (< 76 fl suggests microcytic anemia)
• Transferrin saturation (< 20% indicates iron deficiency)

Targeted Investigation Based on Suspected Etiology

• For patients > 45 years with iron deficiency anemia (IDA):

  • Upper GI endoscopy with small bowel biopsies
  • Lower GI examination (colonoscopy or barium enema)
  • Rule out occult malignancy, celiac disease, and other GI sources of blood loss 1

• For patients < 45 years:

  • If upper GI symptoms: endoscopy with small bowel biopsy
  • Test for celiac disease (antiendomysial antibodies and IgA levels)
  • Colonic investigation only if specific indications 1

• For pre-menopausal women:

  • Assess menstrual blood loss (accounts for 5-10% of IDA in this population)
  • Consider pictorial blood loss assessment charts (80% sensitivity/specificity) 1

Treatment Approach

Iron Deficiency Anemia

1. Oral Iron Therapy (First-Line):

   • Ferrous sulfate 200 mg three times daily (most cost-effective option)
   • Alternatives: ferrous gluconate or ferrous fumarate at equivalent doses
   • Consider liquid preparations if tablets not tolerated
   • Add ascorbic acid to enhance iron absorption if response is poor 1, 2
   • Monitor for expected hemoglobin rise of 2 g/dL after 3-4 weeks 1

2. Parenteral Iron (Reserved for specific situations):

   • Indications: intolerance to at least two oral preparations, non-compliance
   • Disadvantages: painful administration (IM), expensive, risk of anaphylactic reactions
   • Note: Rise in hemoglobin is no faster than with oral preparations 1

3. Duration of Therapy:

   • Continue iron supplementation for three months after correction of anemia to replenish iron stores 1

Follow-up Monitoring

• Monitor hemoglobin and red cell indices every three months for one year, then after another year
• Provide additional iron if hemoglobin or MCV falls below normal
• Consider further investigation only if hemoglobin and MCV cannot be maintained 1

Special Populations

Chronic Kidney Disease

• Evaluate iron status before and during treatment
• Maintain iron repletion while using erythropoiesis-stimulating agents (ESAs) if needed
• Target hemoglobin should not exceed 11 g/dL due to increased cardiovascular risks 3, 4

Vitamin B12 Deficiency

• For pernicious anemia: intramuscular cyanocobalamin 100 mcg daily for 6-7 days, then alternate days for 7 doses, then every 3-4 weeks, followed by 100 mcg monthly for life
• Administer folic acid concomitantly if needed 5

Common Pitfalls and Caveats

1. Failure to identify underlying cause:

   • Treating symptoms without addressing the source of blood loss or malabsorption leads to recurrence
   • Up to 10-15% of patients have dual pathology (lesions in both upper and lower GI tracts) 1

2. Inadequate follow-up:

   • Patients not responding to iron therapy should be reassessed for:
     • Poor compliance
     • Misdiagnosis
     • Continued blood loss
     • Malabsorption 1

3. Inappropriate parenteral iron use:

   • Should be reserved for specific indications, not routine use
   • Does not provide faster hemoglobin correction than oral therapy 1

4. Co-morbidity considerations:

   • Carefully assess the appropriateness of invasive investigations in patients with severe co-morbidities
   • Discuss risks and benefits with patients and caregivers 1

5. Overlooking non-GI causes:

   • Consider urinary tract tumors (exclude hematuria)
   • Assess for chronic inflammatory conditions that affect iron utilization 1, 6

By following this structured approach to diagnosis and management, most patients with anemia can achieve resolution within six months, with appropriate iron repletion and correction of the underlying cause.