What are the initial steps and treatment options for managing severe anaemia?

Management of Severe Anaemia

For severe anaemia, immediately transfuse packed red blood cells to achieve a target hemoglobin of 7-8 g/dL in stable patients, while simultaneously investigating the underlying cause and correcting iron deficiency with intravenous iron therapy. 1, 2

Immediate Transfusion Strategy

Transfuse 2-3 units of packed red blood cells immediately for patients with hemoglobin <7 g/dL or those with severe symptoms at any hemoglobin level. 1, 2 Each unit increases hemoglobin by approximately 1 g/dL. 2

Transfusion Thresholds by Clinical Context

• Stable, non-cardiac patients: Target Hb 7-8 g/dL as the initial goal 3, 1, 4
• Patients with cardiovascular disease or acute coronary syndrome: Consider higher threshold (>8 g/dL) due to increased risk of cardiac events with restrictive strategies 1, 2
• Septic shock patients: Maintain restrictive threshold of Hb <7 g/dL, as no mortality benefit exists with higher targets 1
• Hemodynamically unstable patients: Transfuse regardless of absolute hemoglobin value based on symptoms 2

Transfusion Technique

Administer single units sequentially rather than multiple units simultaneously, reassessing hemoglobin after each unit. 1 This minimizes transfusion-related complications. Check hemoglobin 1 hour post-transfusion to confirm response, then monitor daily until stable. 2

Provide continuous cardiac monitoring during transfusion and watch for signs of transfusion reactions or volume overload. 1, 2

Concurrent Diagnostic Workup

Do not delay transfusion while awaiting diagnostic results—treatment and diagnosis must proceed simultaneously. 2

Essential Initial Tests

• Complete blood count with reticulocyte count: Reticulocyte count >10 × 10⁹/L indicates regenerative anaemia 1
• Peripheral blood smear: Look for schistocytes (hemolysis/TTP), malaria parasites, or other morphologic abnormalities 3, 1
• Hemolysis markers: LDH, indirect bilirubin, haptoglobin levels 1
• Iron studies: Serum ferritin, transferrin saturation (TSAT), assess for absolute (ferritin <100 ng/mL) or functional iron deficiency (TSAT <20% with ferritin >100 ng/mL) 3
• Direct antiglobulin test (Coombs): If hemolysis suspected 1
• Liver function tests and coagulation panel (PT/INR) 1

Additional Considerations

• Rule out malaria in patients with fever, anaemia, and thrombocytopenia, especially with travel history—severe malaria requires IV artesunate 1
• Pregnancy test in women of childbearing age 1
• Consider platelet transfusion if platelet count <50,000/µL with active bleeding or planned procedures 1

Iron Therapy

Administer intravenous iron for both absolute and functional iron deficiency—oral iron has limited efficacy in severe anaemia. 3, 5, 6

Dosing Strategy

• Absolute iron deficiency (ferritin <100 ng/mL): Give 1000 mg IV iron as single or multiple doses according to product labeling 3
• Functional iron deficiency (TSAT <20%, ferritin >100 ng/mL): Give 1000 mg IV iron, particularly if considering erythropoiesis-stimulating agents 3
• Timing with chemotherapy: Administer IV iron before or after (not same day) cardiotoxic chemotherapy 3

Erythropoiesis-Stimulating Agents (ESAs)

ESAs are NOT appropriate for acute severe anaemia management due to slow onset of action—reserve for chronic anaemia after stabilization. 2, 7

When ESAs May Be Considered (After Acute Phase)

• Cancer patients on chemotherapy: Only if Hb ≤11 g/dL, receiving myelosuppressive chemotherapy with ≥2 months planned, and not curable intent 3, 7
• Chronic kidney disease: After stabilization, targeting lowest dose to reduce transfusion need 7
• Dosing: Epoetin alfa 40,000 units weekly or 150 units/kg three times weekly 3, 7

Critical ESA Warnings

Never target hemoglobin >11 g/dL with ESAs—this increases mortality, myocardial infarction, stroke, and thromboembolism risk. 7 ESAs also increase tumor progression risk in cancer patients. 7

Supportive Measures

• Supplemental oxygen: For respiratory distress with continuous oxygen saturation monitoring 1
• Urinary catheter: Monitor hourly urine output (target >30 mL/h) 1
• Folic acid supplementation: 1 mg daily 3
• Reduce phlebotomy: Minimize diagnostic blood draws (mean daily volume in critical care is 40-80 mL) 3, 1

Common Pitfalls to Avoid

• Do not wait for complete workup before transfusing—symptoms and hemoglobin level together guide immediate transfusion decisions 2
• Do not use ESAs for acute management—they take weeks to work and are contraindicated in acute severe anaemia 2, 7
• Do not transfuse to Hb >10 g/dL in stable patients—liberal strategies increase transfusion requirements without improving outcomes 3, 1
• Do not use oral iron in severe anaemia—IV iron is required for adequate repletion 3, 5
• Do not overlook functional iron deficiency—even with normal/high ferritin, TSAT <20% indicates need for IV iron 3

Special Population: Immune Checkpoint Inhibitor-Related Anaemia

If severe anaemia develops in patients on immune checkpoint inhibitors (Grade 3-4):

• Permanently discontinue checkpoint inhibitor 3
• Hematology consultation immediately 3
• Prednisone 1-2 mg/kg/day (IV if Grade 4 or rapid development) 3
• Transfuse per guidelines above, coordinating with blood bank team 3
• Monitor hemoglobin weekly until steroid taper complete 3