Chapter 3 Flashcards

1
Q

Why is heparin unsuitable for haematologies?

A

It results in poor leucocyte staining

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2
Q

How does haemolysis affect a CBC?

A

^ MCHC and MCH
v RBC count and PCV

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3
Q

How does lipaemia affect the CBC?

A

^ Hgb, MCH, MCHC

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4
Q

How do Heinz bodies affect the CBC?

A

^ MCH, MCHC +/- increased WBC/reticulocytes (analyser dependent)

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5
Q

What can cause an elevated MCH/MCHC?

A

Usually spurious - lipaemia, haemolysis, Heinz bodies
Spherocytosis, eccentrocytosis, hyponatraemia

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6
Q

What are the affects of sample ageing on CBC?

A

Increased MCV and HCT, falsely low MCHC and MCH
WBC morphology deteriorates

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7
Q

How does autoagglutination affect the CBC?

A

Reduced RBC and hct, falsely high MCH, MCHC and MCV

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8
Q

What is the calculation for:
a) HCT?
b) MCHC?
c) MCH?

A

a) HCT = MCVxRBC
b) MCHC = Hb/HCT
c) MCH = Hb x 10/RBC

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9
Q

What is MCV? What does it indicate?
When can it be abnormal?

A

Mean corpuscular volume. Average size of RBCs
^ - regenerative anaemia, non-regenerative anaemia caused by myelodysplasia (ie FeLV), aged sample, autoagglutination
v - Iron deficiency

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10
Q

What is RDW? What does it indicate? When is it abnormal?

A

Red cell distribution width. Variability in erythrocyte size.
^ - regenerative anaemia and iron deficiency anaemia

*more sensitive indicator of altered RBC size than MCV

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11
Q

What is MCH? What does it indicate? How is it calculated?

A

Mean corpuscular haemoglobin
Weight of average RBC - doesn’t take volume into consideration
= Hb/RBC

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12
Q

What is poikilocytosis?

A

Altered cell shape

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13
Q

What is the normal lymphocyte:neutrophil ratio in the dog and cat?

A

D - 3.5:1
C - 2:1

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14
Q

How do cats/dogs eosinophils differ?

A

Cats granules always abundant and rod-shaped, dogs normally round, range from small amounts to abundant

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15
Q

Which breed of dog has different appearing eosinophils?

A

Greyhounds - non-staining granules gives vacuolated appearance

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16
Q

What are Barr bodies and where are they seen?

A

Seen in neutrophils of females, small protuberance from nucleus at one side - site of X-chromosone

17
Q

What is MCHC, what does it indicate and how is it calculated?

A

Mean corpuscular haemoglobin concentration, mean haemoglobin concentration per RBC
= Hb/HCT

18
Q

What can cause decreased MCHC?

A

Regenerative anaemia, iron deficiency

19
Q

What can increase MCHC?

A

Haemolysis, lipaemia, Heinz Body anaemia, spherocytosis (sometimes), oxyglobin, hyponatraemia

20
Q

What effects do oxyglobin administration have on the CBC?

A

Hb, MCH, MCHC

21
Q

What effects to hyponatraemia have on the CBC?

A

Elevated MCHC, reduced MCV