Anti-Thrombic Therapy

Question 1

Difference between a thrombus in arterial circulation vs venous circulation

Answer 1

Arterial - High pressure forms them + platelet rich

Venous - Low pressure forms them + fibrin rich

Question 2

Result of arterial thrombosis in coronary circulation

Answer 2

MI

Question 3

Result of arterial thrombosis in cerebral circulation

Answer 3

Stroke

Question 4

Result of arterial thrombosis in peripheral circulation

Answer 4

Peripheral vascular disease, rest pain, gangrene

Question 5

How is MI caused by arterial thrombosis diagnosed

Answer 5

1. History
2. ECG
3. Cardiac enzymes

Question 6

How is CVA caused by arterial thrombosis diagnosed

Answer 6

1. History + Examination
2. CT Scan
3. MRI scan

Question 7

How is Peripheral vascular disease caused by arterial thrombosis diagnosed

Answer 7

1. History
2. Examination
3. Ultraosund
4. Angiogram

Question 8

How is MI treated

Answer 8

1. Aspirin
2. LMWH or Fondraparinux
3. Thrombolytic therapy (streptokinase + tissue plasminogen activator)

Question 9

What is streptokinase

Answer 9

1. Breaks down clots in STEMIs (ST elevated MIs)

Question 10

How does streptokinase function

Answer 10

Activates plasminogen to plasmin and breaks down fibrin

Question 11

How does Tissue plasminogen activator work

Answer 11

Generates plasmin which breaks down fibrin

Question 12

How are strokes treated from thrombosis

Answer 12

1. Aspirin or Clopidogrel, prasugrel, ticagrelor
2. TPA (narrow window to use this)
3. Treat risk factors

Question 13

What is cyanosis

Answer 13

Blue colouring to the skin due to lack of blood flow

Question 14

How is Venous thrombosis investigated

Answer 14

1. DVT compression ultrasound

2. V/Q or perfusion scan

Question 15

What three conditions can increase risk of venous thrombosis

Answer 15

1. Anti-phospholipid syndrome
2. Lupus anticoagulant
3. Hyperhomhocysteinaemia

Question 16

Genetic causes for venous thrombosis

Answer 16

1. Antithrombin deficiency
2. Protein C deficiency
3. Protein S deficiency

Question 17

How is Venous thrombosis treated

Answer 17

1. LMWH wight adjusted dose
2. Oral Warfarin 3-6 months
3. OR DOAC for 3-6 months

Question 18

Name a DOAC

Answer 18

Rivaroxaban

Question 19

How is Heparin levels monitored

Answer 19

APTT, aim ratio of 1.8-2.8 by continuous infusion

Question 20

Why is LMWH better than unfratcioned heparin

Answer 20

1. Smaller molecule so less variation in the dose given nd can be really excreted

Used once daily

Question 21

When is LMWH given

Answer 21

Treat prophylaxis and for preventing blood clotting

Question 22

How much aspirin is given in arterial thrombosis

Answer 22

75-300mg

Question 23

How does clopidogrel act

Answer 23

Inhibits ADP-induced platelet aggregation

Question 24

How does Warfarin act

Answer 24

Prevents synthesis of active factors II, VII, IX and X

Antagonises vit K

Prolongues PTT

Question 25

Half life of warfarin

Answer 25

36 hours

Question 26

Cons of using Warfarin

Answer 26

1. Difficult to use 2. Individual variation in dose 3. Need to monitor 4. Measure INR

Question 27

Target range of warfarin

Answer 27

2-3

Question 28

What are DOACs

Answer 28

Oral anticoagulant drugs

Question 29

How do DOACs function

Answer 29

Act directly on factor II and X

Question 30

Pros os using DOACAs

Answer 30

No need for blood monitoring and shorter half lives

Question 31

When are DOACS given

Answer 31

Treatment of AF and DVT/PE

Question 32

When can DOACS not be used

Answer 32

Pregnancy