What is the appropriate management plan for a patient with anemia?

Management Plan for Anemia

The appropriate management of anemia requires a systematic diagnostic workup to identify the underlying cause, followed by targeted treatment including iron supplementation for iron deficiency, vitamin B12/folate replacement for deficiencies, erythropoietin for specific indications, and restrictive transfusion strategies when needed.

Initial Diagnostic Evaluation

Define and Confirm Anemia

• Anemia is defined as hemoglobin <13 g/dL in men and <12 g/dL in women 1
• Obtain complete blood count with mean corpuscular volume (MCV), reticulocyte count, and peripheral blood smear 1, 2
• Check iron studies (ferritin, transferrin saturation), vitamin B12, folate, TSH, and inflammatory markers (CRP) 1, 2

Classify by MCV and Reticulocyte Count

The diagnostic approach follows a structured algorithm 1:

Microcytic anemia (MCV <80 fL):

• Perform iron profile: ferritin <100 μg/L and transferrin saturation <20% indicates iron deficiency 1
• Ferritin is the most powerful test for iron deficiency 1
• Consider hemoglobin electrophoresis in appropriate ethnic backgrounds to exclude thalassemia 1

Normocytic anemia (MCV 80-100 fL):

• Check creatinine for renal failure 1
• Evaluate for inflammatory anemia, mixed deficiencies, or endocrine disorders 1

Macrocytic anemia (MCV >100 fL):

• Check TSH, folate (<10 nmol/L indicates deficiency), and vitamin B12 (<150 pmol/L indicates deficiency) 1
• If B12 level is borderline, measure methylmalonic acid (>271 nmol/L confirms deficiency) 1

Gastrointestinal Evaluation for Iron Deficiency Anemia

Men and Postmenopausal Women

All men and postmenopausal women with confirmed iron deficiency anemia require bidirectional endoscopy unless there is documented significant non-gastrointestinal blood loss 1:

• Perform upper endoscopy (esophagogastroduodenoscopy) with small bowel biopsies to screen for celiac disease (present in 2-3% of IDA patients) 1
• Perform colonoscopy or CT colonography for lower GI evaluation 1
• Only advanced gastric cancer or celiac disease on upper endoscopy should deter lower GI investigation, as dual pathology occurs in 10-15% of patients 1
• Screen all patients for celiac disease with transglutaminase antibody (IgA type) and total IgA 1, 3
• Test for Helicobacter pylori and eradicate if present in patients with recurrent IDA 1

Premenopausal Women

• Screen for celiac disease in all premenopausal women with IDA 1
• Consider bidirectional endoscopy based on clinical judgment, particularly if age >40 years, severe anemia, or family history of colorectal cancer 1, 3

Further Small Bowel Investigation

Small bowel investigation is indicated only if 1:

• Transfusion-dependent anemia despite negative bidirectional endoscopy
• Visible blood loss (melena) with negative initial workup
• Red flag symptoms (weight loss, abdominal pain, elevated CRP) 3
• Hemoglobin cannot be maintained with iron therapy 1

Use capsule endoscopy or deep enteroscopy with distal attachment to detect and treat angioectasias 1

Iron Replacement Therapy

Oral Iron Supplementation

Oral iron is first-line therapy for iron deficiency anemia 1, 4:

• Prescribe 100-200 mg elemental iron daily (ferrous sulfate, ferrous fumarate, or ferrous gluconate) 1, 3
• Take on empty stomach for optimal absorption; if not tolerated, take with meals or reduce dose 1
• Taking with 500 mg vitamin C or meat protein enhances absorption 1
• Treatment duration: 3-6 months to normalize hemoglobin and replenish iron stores 1, 3
• Monitor hemoglobin and iron studies to confirm response 1, 4

Intravenous Iron Therapy

Use IV iron when 1, 4, 3:

• Oral iron is not tolerated or causes significant side effects
• Intestinal malabsorption (celiac disease, inflammatory bowel disease, bariatric surgery)
• Chronic inflammation preventing oral iron absorption
• Severe iron deficiency requiring rapid repletion
• Patient is receiving erythropoietin therapy 1

Vitamin B12 and Folate Replacement

Vitamin B12 Deficiency (Pernicious Anemia)

Parenteral vitamin B12 is required for life in pernicious anemia 5:

• Initial treatment: 100 mcg intramuscularly daily for 6-7 days 5
• If clinical improvement and reticulocyte response occur, give 100 mcg on alternate days for 7 doses 5
• Then 100 mcg every 3-4 days for 2-3 weeks 5
• Maintenance: 100 mcg intramuscularly monthly for life 5
• Monitor serum potassium closely in first 48 hours of treatment 5
• Administer folic acid concomitantly if deficient 5

Critical warning: Vitamin B12 deficiency progressing >3 months produces permanent spinal cord degeneration 5. Folic acid >0.1 mg/day may mask B12 deficiency while allowing irreversible neurologic damage 5.

Folate Deficiency

• Supplement with folic acid 1 mg daily 1
• Ensure vitamin B12 deficiency is excluded or treated simultaneously 5

Erythropoietin Therapy

Critical Care Patients

Erythropoietin is recommended for anemic critical care patients, especially after trauma, in the absence of contraindications 1:

• Avoid iron therapy except when given with erythropoietin 1

Chronic Kidney Disease

Initiate erythropoietin when hemoglobin <10 g/dL in dialysis patients 6:

• Starting dose: 50-100 Units/kg IV or subcutaneously 3 times weekly 6
• Target: Use lowest dose to reduce transfusion need; do not target hemoglobin >11 g/dL (increased mortality risk) 6
• Reduce dose by 25% if hemoglobin rises >1 g/dL in 2 weeks 6
• Ensure iron repletion before and during therapy 6

Cancer Patients on Chemotherapy

• Initiate only if hemoglobin <10 g/dL with ≥2 months planned chemotherapy 6
• Adults: 150 Units/kg subcutaneously 3 times weekly or 40,000 Units weekly 6
• Reduce dose by 25% if hemoglobin increases >1 g/dL in 2 weeks 6

Transfusion Strategy

Critical Care and Hospitalized Patients

Adopt a restrictive transfusion strategy 1:

• Use single-unit transfusion policy 1
• Transfuse to minimum hemoglobin needed to relieve symptoms (7-8 g/dL in stable, non-cardiac patients) 1
• Red blood cells of any storage time are acceptable 1

Surgical Patients

• Reserve transfusions for patients with or at risk of cardiovascular instability 1
• Erythropoietin may reduce transfusion needs in elective noncardiac, nonvascular surgery when hemoglobin 10-13 g/dL 6

Prevention Strategies in Critical Care

Implement phlebotomy reduction strategies to prevent iatrogenic anemia 1:

• Minimize blood sampling frequency and volume
• Use pediatric collection tubes when appropriate
• Coordinate laboratory testing to reduce draws

Monitoring and Follow-Up

• Monitor hemoglobin every 3 months in patients with chronic kidney disease (GFR <30 mL/min/1.73 m²) 1
• Check reticulocyte count, hematocrit daily on days 5-7 of B12 therapy, then frequently until normal 5
• Monitor iron studies weekly during steroid taper for immune-mediated hemolytic anemia 1
• Reassess if no reticulocyte response or inadequate hemoglobin improvement after appropriate therapy 5, 6

Special Considerations

Celiac Disease

• Ensure strict adherence to gluten-free diet to improve iron absorption 1
• Oral iron supplementation based on severity; use IV iron if stores don't improve 1

Angioectasias

• Endoscopic treatment with argon plasma coagulation or hemostatic clips 1
• Always accompany with iron replacement 1
• Reserve medical therapy for refractory cases 1