At what severity level is anemia treated?

Treatment Thresholds for Anemia

Anemia should be treated when hemoglobin levels fall below 10 g/dL in patients receiving chemotherapy, while a more restrictive approach (Hb < 7-8 g/dL) is appropriate for most other clinical scenarios. 1, 2

Definition and Classification of Anemia

Anemia is defined as a reduction of hemoglobin concentration, red-cell count, or packed cell volume below normal levels. It can be categorized by severity:

• Mild anemia: Hemoglobin ≤11.9 g/dL and ≥10 g/dL 1
• Moderate anemia: Hemoglobin ≤9.9 g/dL and ≥8.0 g/dL 1
• Severe anemia: Hemoglobin <8.0 g/dL 1

Treatment-related anemia is graded according to the National Cancer Institute-Common Toxicity Criteria:

• Grade 0: Within normal limits 1
• Grade 1: Lower normal limit to 10.0 g/dL 1
• Grade 2: 8.0 to <10.0 g/dL 1
• Grade 3: 6.5 to <8.0 g/dL 1
• Grade 4: <6.5 g/dL 1

Treatment Thresholds by Clinical Scenario

Cancer Patients Receiving Chemotherapy

• Treatment with erythropoiesis-stimulating agents (ESAs) should be considered when hemoglobin ≤10 g/dL 1
• Goal is to increase hemoglobin by <2 g/dL or prevent further decline 1
• Primary aims are to prevent red blood cell transfusions and improve quality of life 1

Cancer Patients NOT Receiving Chemotherapy

• ESAs are not indicated and may increase mortality risk when targeting Hb of 12-14 g/dL 1
• For patients treated with curative intent, ESAs should be used with caution 1

Acute Blood Loss/Critical Illness

• Restrictive transfusion strategy (Hb < 7-8 g/dL) is associated with better outcomes than liberal transfusion (Hb < 9-10 g/dL) in many clinical settings 2
• Transfusion decisions should be guided by patient symptoms and preferences in conjunction with hemoglobin levels 2

Special Populations

• Evidence is lacking for optimal transfusion thresholds in patients with:
  • Preexisting coronary artery disease 2
  • Acute myocardial infarction 2
  • Congestive heart failure 2
  • Myelodysplastic neoplasms 2

Evaluation Before Treatment

Before initiating treatment for anemia, a thorough evaluation should be conducted:

• Complete blood count with reticulocyte count 1
• Iron studies (serum iron, transferrin saturation, ferritin) 1
• Inflammatory markers (C-reactive protein) 1
• Vitamin B12 and folate levels 1, 3
• Peripheral blood smear examination 1
• Assessment for occult blood loss in stool and urine 1
• Evaluation of renal function 1
• Bone marrow examination when indicated 1
• Coombs testing in patients with chronic lymphocytic leukemia, non-Hodgkin's lymphoma, or history of autoimmune disease 1

Treatment Approaches

Iron Deficiency Anemia

• Oral iron supplementation (100-200 mg elemental iron daily) for 3-6 months to normalize hemoglobin and replenish iron stores 4
• Consider lower doses if side effects occur 4
• Intravenous iron therapy when oral treatment is ineffective, causes side effects, or in cases of intestinal malabsorption or prolonged inflammation 4

Anemia of Inflammation

• Primary approach is treatment of the underlying inflammatory disease 5
• Consider iron supplementation therapy and/or erythropoietin-stimulating agents if anemia persists 5
• Blood transfusions should be reserved for life-threatening anemia 5

Severe Anemia

• Red blood cell transfusion for hemoglobin <7-8 g/dL in most clinical settings 2, 6
• Higher transfusion thresholds may be considered for patients with cardiac disease, though evidence is limited 2

Common Pitfalls and Caveats

• Empiric use of nutritional supplements to treat anemia of uncertain etiology is discouraged 6
• All causes of anemia should be identified and addressed before using ESAs 1
• Severity of anemia often correlates with severity of the underlying disease 3
• Intravenous iron is generally preferred over oral iron in patients with complex medical disorders 2
• ESAs should be used cautiously in patients being treated with curative intent due to potential risks 1