A routine CBC of a patient on your ward comes back showing Hgb 90, MCV 86. Your patient has been complaining of new onset fatigue for the past two days.
- What classification of anemia is this?
This patient is presenting with normocytic anemia. Specific labwork that can help with the diagnosis includes:- CBC – Hgb, MCV (80-100 fL normocytic), RDW (if high, suspect a mixed picture)
- Reticulocyte count (should be elevated in an acute bleed or hemolytic process)
- Fe studies
- B12 levels
- What is your differential diagnosis?
The differential diagnosis for normocytic anemia is extensive, but can be thought of as arising from increased loss, increased destruction, increased sequestration, and/or decreased production.
The differential therefore includes:- Acute blood loss (increased loss)
- Hemolytic anemia (increased destruction)
- Hereditary – hemoglobinopathies, disorders of RBC membrane, RBC enzyme deficiencies
- Acquired – mechanical hemolysis, autoimmune, paroxysmal nocturnal hemoglobinuria
- Hypersplenism (increased sequestration)
- Primary bone marrow dysfunction (decreased production)
- Bone marrow invasion (leukemia)
- Aplastic anemia
- Myeloproliferative disorder
- Red blood cell aplasia
- Secondary causes of decreased production
- Chronic kidney disease
- Hypothyroidism
- Hypopituitarism
- Hypoadrenalism
- Anemia of chronic disease/inflammation
- Overhydration (dilutional)
- Which of these diagnoses are you most worried about at this time?
An acute bleed must be ruled out in a patient with new onset normocytic anemia.
Resource
Brill JR and Baumgardner DJ. Normocytic Anemia. Am Fam Physician. 2000, 62:2255-2263.
