Anemia (OSCE)

Initial Assessment

1. Is the patient anemic?

• Hgb < 12 g/dL, Hct < 37% in females, Hgb < 14 g/dL, Hct < 42% in males

2. Is this anemia acute or chronic?

3. Is this dilutional anemia?(hematocrit)

4. What is the size of the RBC? (MCV)

5. Is body appropriately responding? (reticulocyte count)

6. What does the peripheral blood smear show?

Microcytic

• Fe deficiency - ↓ ferritin, ↑ TIBC
  • < 15 confirms, 15 - 25 suggests, 25 - 100 not helpful, > 100 rules out

• Anemia of chronic disease (ACD)
  • associated with inflammation (RA, infection, carcinoma)
  • ↓ TIBC (Fe not transferred to developing RBCs)

• Thalassemia
  • target cells, serum electrophoresis (↑ HbgA2)

• Lead poisoning - ↑ serum Pb

• Sideroblastic - ↑ in cellular iron uptake
  • ↑ ferritin, ring sideroblasts

Macrocytic

• megaloblastic anemia - hypersegmented polymorphonucleocytes(PMNs)
• defects in DNA synthesis that lead to hematologic abnormalities
• ↓ folate or ↓ vit B12
• drugs: methotrexate, azathioprine (Imuran - immunosuppressant)

• myelodysplasia
  • dimorphic smear (micro/macrocytosis)

• chronic liver disease
  • ↑ GGT, target cells

Normocytic

High reticulocyte

• Hemolysis
  • hypersplenism, drugs, sepsis, autoimmune
  • cell morphology (from peripheral smear) is crucial: see below
    • ↑ LDH, ↑ bilirubin, ↑ serum Hbg, ↓ haptoglobin (Hgb scavenger), + Coombs

Low reticulocyte

• bone marrow failure
  • pancytopenia (↓ WBC, ↓ plt)
  • BM aspirate (cell morphology), BM biopsy (structure)

Misc

Red cell distributuion width (RDW)

• Normal:
  • ACD, thalassemia

• Increased
  • iron deficiency
  • duel deficiency (fe, folate)
  • pernicious anemia
  • liver disease
  • AIHA

Blood smear

Shape

• normal: biconcave
• spherocyte - immune hemolytic anemia
• schistocytes - MAHA: DIC, vasculitis, prosthetic heart valves, HUS/TTP
• sickle cell - sickle cell disorders
• target cell - liver disease, thalassemia, Fe deficiency
• teardrop cell - myelofibrosis

Distribution

• rouleaux formation - aggregates of RBC resembling stacks of coins
• paraprotein (multiple myeloma)

Inclusion

• nuclei (immature RBC)
  • serious medical disease
  • severe anemia, leukemia, bone marrow metastases

• Heinz bodies (denatured hemoglobin)
  • G6PD deficiency

• Howell-Jolly bodies
  • post-splenectomy, hyposplenism

• basophilic stippling (blue granulations of variable size and number, aggregation of ribosomes)
  • lead intoxication, thalassemia

Other OSCE modules