UNIT 1 - Lecture 6: Erythrocytosis

Question 1

What is erythrocytosis?

Answer 1

Increase in RBC # above RI

Question 2

What is polycythemia vera?

Answer 2

Clonal myeloproliferative disorder with a neoplastic proliferation of all marrow cell precursors

Question 3

What breeds have a higher PCV/Hct compared to others?

Answer 3

Greyhounds, Afghan hounds, Salukis, Whippets (Avg = 50-60%)

Question 4

What is hemoconcentration?

Answer 4

Loss of intravascular water

Question 5

What is the most common cause of relative erythrocytosis?

Answer 5

Dehydration

Question 6

Up to ___% RBCs can be stored in the spleen –> released with _____.

Answer 6

30%, splenic contraction

Question 7

What is secondary absolute erythrocytosis?

Answer 7

Increased erythropoiesis secondary to endocrine disorders or production of EPO

Question 8

What is an appropriate cause of secondary absolute erythrocytosis?

Answer 8

EPO release occurs to improve O2 carrying capacity in blood

Question 9

What is an inappropriate cause of secondary absolute erythrocytosis?

Answer 9

EPO released from neoplasms or kidney secodary to regional hypoxia

Question 10

Primary absolute erythrocytosis is a diagnosis of _____.

Answer 10

exclusion

Question 11

What can cause primary absolute erythrocytosis and how commonly is it seen?

Answer 11

Chronic myeloproliferative disorder/neoplasia, autonomous RBC production independent of EPO;

RARE

Question 12

What are the cnsequences of erythrocytosis?

Answer 12

1. Slow blood can increase the risk of thrombosis
2. Decreased O2 delivery –> neuro disturbances, blindness, seizures, etc.
3. Increased volume can –> heart failure
4. Hyperemic skin and MM