haemostasis and thrombosis

Question 1

what methods would you use to diagnose deep vein thrombosis?

Answer 1

D-dimer test
ultrasound
two level wells score

Question 2

what are the 3 stages in the formation of a thrombin?

Answer 2

1. tissue factor presenting cells activate factors X&V forming a prothrombinase complex
2. Prothrombinase complex activates factor II (prothrombin) creating factor IIa (thrombin)
3. Antithrombin (AT-III)
   inactivates fIIa & fXa

Question 3

what do anticoagulants target?

Answer 3

1. inhibit factor IIa
2. inhibit factor Xa
3. increase activity of AT-III
4. reduce levels of other factors

Question 4

give an example of a drug that inhibits factor IIa

Answer 4

Dabigatran

Question 5

give an example of a drugthat inhibits factor Xa

Answer 5

Rivaroxaban

Question 6

give an example of a drug that increases the activity of AT-III

Answer 6

Heparin
low molecular weight herapins

these are no longer available as common medications, sometimes given in hospital setting as IV injections as the onset is as rapid

Question 7

give an example of a drug that reduces levels of other factors

Answer 7

warfarin (indirect, vitamin K antagonist)

–> vitamin K required for generation of factors II, VII, IX & X

Question 8

what are the risk factors for DVT and pulmonary embolism?

Answer 8

VIRCHOW’S TRIAD

1. Rate of blood flow
   Blood flow slow/stagnating –>no replenishment of anticoagulant factors & balance adjusted in favour of coagulation
2. Consistency of blood
   Imbalance between pro-coagulation & anticoagulation factors
3. Blood vessel wall integrity. more likely to get thrombosis if vessels are damaged
   Damaged endothelia –> blood exposed to pro-coagulation factors

Question 9

what are the three parts of VIRCHOW’S TRIAD

Answer 9

1. rate of flow
2. consistency of blood
3. blood vessel wall integrity

Question 10

what might elevated troponin indicate?

Answer 10

myocardial infarction

Question 11

what is the difference between ST elevated and non ST elevated MI?

Answer 11

NSTEMI- partially occluded

STEMI- complete occlusion

Question 12

what activates platelets?

Answer 12

thrombin (fIIa)

Question 13

what drug is used to prevent platelet activation and the MOA

Answer 13

Clopidogrel

ADP (P2Y12) receptor antagonist

Question 14

what drug is used to inhibit the production of TXA2? and MOA

Answer 14

aspirin

irreversible COX-1 inhibitor

Question 15

what drug prevents platelet aggregation?

Answer 15

abciximab

Question 16

what does the d dimer test detect?

Answer 16

fibrin degradation products

Question 17

what are the two types of stroke?

Answer 17

occlusion stroke

haemorrhagic stroke

Question 18

what is the difference between red and white thrombi?

Answer 18

Vein thrombosis associated with red blood cells producing a fibrin-rich “ red clot, “

arterial thrombi on atherosclerotic lesions with active inflammation are rich in platelets, giving the appearance of a white clot