Coagulation

Question 1

What are the vitamin K dependent coagulation factors?

Answer 1

Factors II, VII, IX and X

Question 2

What are the labile coag factors?

Answer 2

Factor V and VIII

Question 3

What is Hageman deficiency?

Answer 3

Congenital coagulopathy = lack of factor 12, common in cats
BUT often asymptomatic, is more of an in vitro issue (classical v. Cell based model of coagulation)

Question 4

What changes will be present in coag testing with hagemanns deficiency in cats?

Answer 4

Prolonged APTT, normal PT (because factor 12 is part of intrinsic pathway, which APTT measures

Question 5

Types of von willebrand disease?

Answer 5

Type 1 - low plasma conc of vwf, normal vwf multimers = mild-mod bleeding tendency
Type 2 - variable plasma conc of vwf, absence of high molecular weight multimers = mod-severe bleeding tendency
Type 3 - absence if any plasma vwf = severe bleeding tendency

Question 6

What are the fat soluble vitamins?

Answer 6

Vitamin A, D, E, K

Question 7

Differentials for a primary haemostasis disorder?

Answer 7

Thrombocytopenia (<50 is associated with spontaneous bleeding)
Thrombocytopathia, congenital or acquired

Question 8

What is the mechanism of fibrinolysis?

Answer 8

Plasminogen binds fibrin
Tissue type (tPA) and urokinase-type (uPA) plasminogen activators cleave it into plasmin

Question 9

Mechanism of TXA?
(And epsilon-aminocaproic acid, EACA)

Answer 9

Lysine analogue
Competitively binds C terminal sites on plasminogen
Prevents this from binding to fibrin, therefore it can’t form plasmin

Question 10

How does hematocrit affect TEG results?

Answer 10

High HCT - relatively hypocoagulable tracings
Low HCT - relatively hypercoagulable tracings