Platelets and Coagulation- The essentials

Question 1

In what species are thrombocytes not nucleated cells?

Answer 1

Mammals

Question 2

What protein stimulates the production of megakaryocytes and development of platelets

Answer 2

Thrombopoietin

Question 3

What is the average platelet life span?

Answer 3

5-10 days

Question 4

What are some potential challenges for a platelet analyser?

Answer 4

Struggle to separate especially if the erythrocytes are small and the platelets are large

Question 5

What breed of dog has large platelets?

Answer 5

Cavalier King Charles Spaniel

Question 6

What is Thrombocytosis?

Answer 6

Occurs when another disease/ condition causes you to have a high platelet count

Question 7

What are some conditions that may cause you to have a high platelet count?

Answer 7

Inflammation
response to iron deficiency
recovery from previous thrombocytopenia
Response to epinephrin or exercise

Question 8

What is Cytopenia?

Answer 8

Having low levels of different blood cells

Question 9

What are some different ways cytopenia can occur?

Answer 9

Increased loss
Decreased production
Increased consumption
Sequestration

Question 10

What are some ways thrombocytopenia can occur?

Answer 10

response to some drugs
spleen removing cells from circulation

Question 11

What is the difference between primary and secondary IMHA?

Answer 11

Primary- where the immune system attacks its own red blood cells
Secondary- where an underlying disease modifies the red blood cells

Question 12

What is disseminated intravascular coagulation?

Answer 12

abnormal blood clotting throughout the bodies vessels

Question 13

What is envomation?

Answer 13

The injection of venom

Question 14

What is haemostasis?

Answer 14

Balance between clot formation and clot breakdown
These processes are in continual balance

Question 15

What is primary haemostasis?

Answer 15

Evaluation of the platelets

Question 16

What is a coagulopathy?

Answer 16

A condition that affects how your blood clots
it can result in a lack of platelets/ a lack of functioning platelets

Question 17

What is secondary haemostasis?

Answer 17

The formation of fibrin through the clotting cascade

Question 18

What is primary haemostasis?

Answer 18

The initial response of the body to vascular injury and involves interactions between platelets

Question 19

What kind of pathway is the PT pathway?

Answer 19

extrinsic

Question 20

What kind of pathway is the APTT pathway?

Answer 20

intrinsic

Question 21

Why cant you use the APTT Pathway testing for avians?

Answer 21

They do not have factor 12

Question 22

What is fibrinolysis?

Answer 22

Breakdown of a clot

Question 23

What kind of plasma is required to assess clotting factors?

Answer 23

citrate plasma

Question 24

What are D-Dimers and FDP’s
evidence of?

Answer 24

Evidence of Clot breakdown

Question 25

What is viscoelastic testing?

Answer 25

provides a full hemostasis overview from a patient whole blood sample

Question 26

What kind of state cannot be identified on PT/ APTT testing

Answer 26

Hypercoagulable states

Question 27

What are some platelet disorders that can be inherited?

Answer 27

Glanzmann’s thrombasthenia vWD

Question 28

What is type I disease?

Answer 28

all vWF multimers are present but proportionately low

Question 29

What is type II disease?

Answer 29

deficiency of vWF multimers with high molecular weight

Question 30

What is type III disease?

Answer 30

absence of all vWF multimers

Question 31

What is vWD factor important for?

Answer 31

its important for platelet adhesion and aggregation, it competes with factor 7 for stabilisation

Question 32

What is the clinical presentation of primary haemostasis/ decreased platelets

Answer 32

Haemorrage e.g * Petechiae – 1-4mm – * Epistaxis * Haematuria

Question 33

What is the clinical presentation of secondary haemostasis/ decreased clotting factors

Answer 33

* Ecchymoses * Haematomas * Haemorrhage into body cavities, joints

Question 34

What is a D-Dimer

Answer 34

A fibrin degredation | evidence of clot degredation

Question 35

Give an example of a coagulpathy

Answer 35

Von Willebrands disease

Question 36

Whys hould you not use a glass tube for measuring clotting factors?

Answer 36

Glass surfaces will activate the clotting factors

Question 37

What does the extrinsic coagulation pathway begin with?

Answer 37

Tissue factor

Question 38

What is the extrinsic pathway also known as?

Answer 38

the PT pathway

Question 39

What is the intrinsic pathway also known as?

Answer 39

the APTT pathway

Question 40

What is type I vWF disease?

Answer 40

all multimers are present but proportionately low

Question 41

What is type II vWF disease?

Answer 41

deficiency of vWF multimers with high molecular weight

Question 42

What is type III vWF disease?

Answer 42

absence of all vWF multimers

Question 43

At what magnification will platelets need to be identified at?

Answer 43

x100 oil immersion

Question 44

Give some examples of things that can cause disseminated intravascular coagulation

Answer 44

* Envenomation * Hepatic disease * infection * necrosis * pancreatitis

Question 45

How can you test the function of platelets in house?

Answer 45

buccal mucousal bleeding test

Question 46

What causes platelet sequestration?

Answer 46

Platelets get stuck in the spleen

Question 47

What causes platelet destruction?

Answer 47

immune-mediated thombocytopenia

Question 48

What causes decreased production of platelets?

Answer 48

response to drugs or an infection

Question 49

What causes platelet consumption?

Answer 49

coagulopathy, e.g DIC