Thrombotic Disorders

Question 1

3 main elements of haemostasis

Answer 1

Primary haemostasis
Blood coagulation
Fibrinolysis

Question 2

Steps of primary haemostasis?

Answer 2

Vessel wall damage leads to:
Vasoconstriction,
Causes platelet adhesion,
Resulting in platelet aggregation

= Primary plug

Question 3

What does primary haemostasis lead to?

Answer 3

A coagulation cascade:

• insoluble fibrin formation
• fibrin cross-linking

Question 4

Steps of fibrinolysis?

Answer 4

Urokinase and tissue plasminogen activator (tPA) and factor XII
Cause plasminogen to be converted into plasmin.

Plasmin then converts fibrin into fibrinogen/ fibrin degradation products

Question 5

Define thrombus

Answer 5

Clot arising in the wrong place

Question 6

Define thromboembolism

Answer 6

Movement of clot along a vessel

Question 7

What is Virchow triad (HvS Hayden vs Skye for Zoe)

Answer 7

Triad of thrombus formation:

Stasis
Hypercoagulability
Vessel damage

Question 8

Examples for each of Virchow triad?

Answer 8

Stasis:

• bed rest,
• travel

Hypercoagulabiltity:

• pregnancy
• trauma

Vessel Damage:
-atherosclerosis

Question 9

Types of thrombosis?

Answer 9

Arterial
Venous
Micro vascular

Question 10

Main cause of arterial thrombus?

Answer 10

Platelets

Called white clot
Can also be caused by fibrin
Principally secondary to atherosclerosis

Question 11

what does arterial thrombus result in?

Answer 11

Ischaemia

Infarction

Question 12

Examples of arterial thromboembolism?

Answer 12

Coronary- MI, unstable angina

Cerebrovascular- stroke, TIA

Peripheral embolism- limb ischaemia

Question 13

Risk factors for arterial thrombosis

Answer 13

Age, 
Smoking,
Sedentary lifestyle,
Hypertension, 
Diabetes mellitus,
Obesity, 
Hypercholesterolaemia

Question 14

Management of arterial thrombosis

Answer 14

Primary prevention:

• lifestyle modification
• treat vascular risk factors

Acute presentation:

• thrombolysis
• antiplatlet/ anticoagulant

Secondary prevention

Question 15

What causes venous thrombus

Answer 15

Fibrin and red cells
So called “red thrombus”

This causes back pressure
Principally due to stasis and hypercoagulability

Question 16

Examples of venous thromboembolism

Answer 16

Limb deep vein thrombosis 
Pulmonary embolism 
Visceral venous thrombosis 
Intracranial venous thrombosis 
Superficial thrombophlebitis

Question 17

Risk factors of venous thrombosis

Answer 17

Stasis/ hypercoagulability
Increasing age,
Pregnancy,
Hormonal therapy,
Tissue trauma, 
Immobility, 
Surgery, 
Obesity, 
Systemic disease, 
Family history

Question 18

Systemic diseases that can cause venous thrombosis

Answer 18

Cancer, 
Myeloproliferative neoplasm
Autoimmune disease:
-IBD
-connective tissue disease eg SLE
-antiphospholipid syndrome: arterial and venous thrombosis

Question 19

How to diagnose venous thrombosis

Answer 19

Protest probability scoring:
-Wells score
-Geneva score 
Ddimer
Doppler ultrasound,
V/P scan
CT pulmonary angiogram

Question 20

Aim of treatment for venous thrombosis

Answer 20

Prevent clot extension,
Prevent clot embolisation,
Prevent clot recurrence in long term treatment

Question 21

Drugs used to treat venous thrombosis

Answer 21

Anticoagulants- LMWH, coumarins (warfarin), DOACs

Thrombolysis in massive PE

Question 22

What is heritable thrombophilia

Answer 22

An inheritable predisposition to venous thrombosis

Question 23

Causes of heritable thrombophilia

Answer 23

Factor V Leiden
Prothrombin G20210A

Antithrombin defiency
Protein C deficiency
Protein S deficiency

Question 24

What causes microvascular thrombus??

Answer 24

Platelets and/or fibrin
Results in diffuse ischaemia
Principally in Disseminated Intravascular Coagulation (DIC)

Question 25

What is DIC

Answer 25

Diffuse systemic coagulation activation

Question 26

Where does DIC occur

Answer 26

In:
Septicaemia,
Malignancy,
Eclampsia

Due to consumption of platelets and clotting factor leading to bleeding

Question 27

What does DIC cause?

Answer 27

Tissue ischaemia
Causing:
-gangrene
-organ failure