Classification of and Diagnostic Approach to anemia

Question 1

Morphologic Classification of Anemia:

based on MCV

Answer 1

Microcytic anemia - when RBCs too small

Normocytic anemia - when RBCs are of normal volume

Macrocytic Anemia - when RBCs are larger than the reference interval

Question 2

Morphologic Classification of Anemia:

Based on MCHC

Answer 2

Hypochromic anemia - when the cells contain less-than-normal hemoglobin concentrations

Normochromic anemia - when they contain a normal hemoglobin concentration

Hyperchromic anemias do not occur - will be falsely increased when the hemoglonin determination is falswly increased because of intravascular hemolysis, lipemia, of the presence of Heinz bodies

Question 3

Answer 3

regenerative anemai

Question 4

Answer 4

nonregenerative

Question 5

Reticulocytes

Answer 5

young, anucleated erythrocytes

Released to the blood in increased numbers as a response to anemia caused by hemolysis or blood loss in most species

Reticulocyte count is the percent of total RBC that are reticulocytes

Used to determine marrow response to anemia

Question 6

Time frame for evidence of a regenerative response

Answer 6

Anemia that develops acutely will appear non-regenerative at first

Within 2-4 days

Increased release of reticulocytes is seen after blood loss or RBC destruction

Peak reticulocyte count is reached in 5-7 days

If anemic > 5 days, no increase in reticulocytes, then the bone marrow is not responding as it should and Anemia is non-regenerative

Question 7

Assessment of Regenerative Response to Anemia in Equids

Answer 7

• Reticulocytes do not circulate in blood of non-anemic horses
• Reticulocytes are not generally released from marrow in regenerative anemia
• Can’t use polychromasia as an indicator of regeneration
  
  • Won’t see it even in regeneration
• Regenerative response in horses is indicated by finding what?
  
  • Macrocytes
  • Increased MCV
  • Anisocytosis
  • Erythroid hyperplasia in bone marrow
  • Trends:
    
    • increasing HCT and MCV over several days

Question 8

Diagnostic Approach to Anemia:

Answer 8

• History and physical Exam:
• Regenerative or Nonregenerative?
  
  • morphologic classification
  • Blood film assessment
  • Reticulocyte count
• If regenerative:
  
  • blood loss or hemolysis
  • External blood loss usually also results in loos of protein too
• Nonregenerative?
  
  • Anemic > 5 days with no evidence of regeneration
  • Biochemistry indicated
  • Are other cell lines affected
  • Bone marrow aspirate may be indicated
  • cat - FIV/FelV status

Question 9

Regenerative Anemia Expected Findings

Answer 9

Macrocytic (high MCV)

Hypochromic (low MCHC)

Heterogeneous (RDW increaesed)

Anisocytosis

Polychromasia (not in horses)

Question 10

Nonregenerative anemia - expected findings

Answer 10

Normocytic (normal MCV)

Normochromic ( normal MCHC)

Hemogeneous (RWD within normal limits)

Minimal Anisocytosis on smear

No to minimal polychromasia on smear