Intro to CBC and Analytic Principles of the Erythrogram

Question 1

What are the components of the CBC?

Answer 1

dot plot
data values
blood smear

Question 2

What are the inidications of the CBC?

Answer 2

evaluate anemia or dehydration
evaluate inflammation, stress, leukemia or parasites
investigate platelet disorders
monitor dx progression
screening
routine health check

Question 3

What are the limitations of the CBC?

Answer 3

snapshot
does not measure fitness
sick animals can have CBC analytes that are within RI
non-specific dx

Question 4

Hct s/PCV

Answer 4

measures RBC density

Question 5

Hct c

Answer 5

calculates RBC density

    10

Question 6

Hgb

Answer 6

measures RBC mass

Question 7

RBC

Answer 7

measures RBC density

Question 8

MCV

Answer 8

mean cell volume - average volume of circulating RBC
measured RBC index

Question 9

MCHC

Answer 9

average [Hgb] in RBC calculated RBC index

 [RBC]

Question 10

MCH

Answer 10

average Hgb content per RBC
calculated RBC index - not often used

[RBC]

Question 11

CHCM

Answer 11

cellular hemoglobin concentration mean
measured RBC index
not commercially reported

Question 12

What can cause a false increase in MCHC?

Answer 12

lipenmia
heinx bodies
hemolysis

Question 13

When comparing Hct and PCV which is affected by agglutination?

Answer 13

Hct - increases with agglutination

Question 14

Which is more accurate, PCV or Hct?

Answer 14

typically PCV - exceeds Hct c by 3%

Question 15

General rule
Hgb x 3 = what?

Answer 15

Hct

Question 16

Usually, increase RBC mass then…

Answer 16

increase Hct, [Hgb] and [RBC]

Question 17

Usually, if decrease RBC mass then…

Answer 17

decrease Hct, [Hgb] and [RBC]

Question 18

Differential diagnoses for macrocytosis

Answer 18

pathology - RBC regeneration
breed specific - not pathologic for miniature schnauzers and poodles
artifacts - prolonged storage, agglutination, hypernatremia, hyperglycemia

Question 19

Differential diagnoses for microcytosis

Answer 19

pathology - iron deficiency, liver dz
host - young animals
artifacts - excess EDTA, hyponatremia

Question 20

What interferents can increase MCHC?

Answer 20

in vitro hemolysis - falsely increases Hb
in vitro hemolysis - falses decreases Hct
lipemia - increases cell lysis
heinz bodies
excess EDTA - shrinks cells
increased turbidity
icterus/hyperbilirubinemia