Anemia (OSCE)
Initial Assessment
edit1. 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?
MCV < 80
(hypochromic) |
normocytic (normochromic)
low reticulocytes |
normocytic
high reticulocytes |
MCV > 100 |
Fe deficiency
Anemia of chronic disease (ACD) |
chronic liver disease
thalassemia trait liver disease megaloblastic marrow failure (pancytopenia) myelodysplasia leukemia alcohol myeloma hypothyroidism mets infection |
blood loss
hemolysis |
lead overload
renal failure (uremia) B12 lack sideroblastic endocrine (thyroid) folate lack ACD hematinic lack drugs |
Microcytic
edit- 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
edit- 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
editHigh reticulocyte
edit- Hemolysis
- hypersplenism, drugs, sepsis, autoimmune
- cell morphology (from peripheral smear) is crucial: see below
- ↑ LDH, ↑ bilirubin, ↑ serum Hbg, ↓ haptoglobin (Hgb scavenger), + Coombs
Low reticulocyte
edit- bone marrow failure
- pancytopenia (↓ WBC, ↓ plt)
- BM aspirate (cell morphology), BM biopsy (structure)
Misc
editRed cell distributuion width (RDW)
edit- Normal:
- ACD, thalassemia
- Increased
- iron deficiency
- duel deficiency (fe, folate)
- pernicious anemia
- liver disease
- AIHA
Blood smear
editShape
edit- 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
edit- rouleaux formation - aggregates of RBC resembling stacks of coins
- paraprotein (multiple myeloma)
Inclusion
edit- 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