What is the best approach to manage an adult patient with severe anemia?

Management of Severe Anemia (Hemoglobin 7.4 g/dL)

Transfuse packed red blood cells immediately using a restrictive threshold of 7 g/dL, administering one unit at a time and reassessing after each unit to target a post-transfusion hemoglobin of 7-9 g/dL. 1

Immediate Transfusion Management

Your patient with hemoglobin 7.4 g/dL requires blood transfusion now. The American Society of Anesthesiologists establishes a restrictive transfusion threshold of 7 g/dL for most hospitalized patients, and your patient falls at this critical level 1, 2.

Transfusion Protocol

• Administer one unit of packed RBCs, then stop and reassess clinical status and repeat hemoglobin before giving additional units 1
• Each unit should increase hemoglobin by approximately 1-1.5 g/dL 1
• Target post-transfusion hemoglobin of 7-9 g/dL - do not exceed 10 g/dL as liberal transfusion strategies increase complications without improving outcomes 1, 3
• Recheck hemoglobin 15-30 minutes after each unit to guide further transfusion decisions 2

Critical Threshold Adjustments

• If cardiovascular disease or acute coronary syndrome is present, use a threshold of 8 g/dL instead of 7 g/dL 1, 2
• If hemodynamically unstable, actively bleeding, or showing signs of end-organ ischemia (chest pain, dyspnea, altered mental status), transfuse immediately regardless of the specific hemoglobin number 1

Diagnostic Workup (Obtain BEFORE Transfusion When Possible)

Order iron studies immediately before transfusion as this provides the most accurate assessment of iron stores 1. Waiting until after transfusion will confound results.

Essential Laboratory Tests

• Iron panel: serum iron, total iron binding capacity (TIBC), serum ferritin, and transferrin saturation 1
• Hemolysis markers: reticulocyte count, lactate dehydrogenase (LDH), indirect bilirubin, and haptoglobin 1, 3
• Peripheral blood smear to assess red cell morphology for iron deficiency, schistocytes, or other abnormalities 3
• Complete blood count with differential to assess other cell lines 3

Iron Replacement Strategy

If iron deficiency is confirmed (ferritin <800 ng/mL AND transferrin saturation <20%), initiate iron replacement therapy 1.

Route Selection

• Intravenous iron is superior and should be first-line in severe anemia 1
• Oral iron (ferrous sulfate 324 mg tablets containing 65 mg elemental iron) is less effective but appropriate for mild cases or when IV access is limited 1, 4
• In critical care patients, iron supplementation alone (without erythropoiesis-stimulating agents) is not recommended to reduce transfusion requirements, as it only increases hemoglobin by 0.31 g/dL 5

Monitoring Strategy

• Continuous cardiac monitoring if hemoglobin remains critically low, as severe anemia carries high risk of cardiac decompensation 3
• Monitor for transfusion reactions during and immediately after administration 2
• Reduce diagnostic phlebotomy volume and frequency to prevent worsening anemia 1, 3
• Recheck hemoglobin daily until stable above 7-8 g/dL 3

Critical Pitfalls to Avoid

• Do not transfuse to hemoglobin >10 g/dL - this increases complications including transfusion-associated circulatory overload, venous thromboembolism, and mortality without improving outcomes 1, 2, 3
• Do not delay transfusion in symptomatic patients - symptoms of tissue hypoxia (chest pain, dyspnea, tachycardia, altered mental status) mandate immediate transfusion regardless of the exact hemoglobin level 1, 2
• Do not give multiple units simultaneously - single-unit transfusions with reassessment minimize transfusion-related complications 2, 3
• Do not delay iron studies - obtain before transfusion for accurate assessment 1

Follow-Up Considerations

• If anemia persists despite iron replacement, consult hematology for alternative or complicating etiologies 1
• Ensure outpatient follow-up is arranged if patient is discharged, as chronic anemia requires ongoing evaluation 6, 7