Thrombotic Disorders

Question 1

What does plasmin do?

Answer 1

Convert fibrin to fibrinogen/fibrin degradation products

Question 2

What is a thrombus?

Answer 2

Clot in the wrong place

Question 3

What is a thromboembolism?

Answer 3

Movement of a clot along a vessel

Question 4

What is Virchow’s triad?

Answer 4

Thrombosis

• stasis
• hypercoagulability
• vessel damage

Question 5

What causes stasis?

Answer 5

Bed rest

Travel

Question 6

What causes hypercoagulability?

Answer 6

Pregnancy

Trauma

Question 7

What causes vessel damage?

Answer 7

atherosclerosis

Question 8

Describe arterial thrombosis

Answer 8

White clot; platelets and fibrin

Results in ischaemia and infarction

Principally secondary to atherosclerosis

Question 9

What are some examples of arterial thromboembolism?

Answer 9

Coronary; MI, unstable angina

Cerebrovascular; stroke, TIA

peripheral; limb ischaemia

Question 10

What are risk factors for arterial thrombosis?

Answer 10

Age
Smoking
Sedentary lifestyle
Hypertension
DM
Obesity
Hypercholesterolaemia

Question 11

How is arterial thrombosis managed?

Answer 11

Primary prevention

• lifestyle modification
• treatment of vascular risk factors

Acute presentation

• thrombolysis
• antiplatelet/anticoagulant drugs

Secondary prevention

Question 12

Describe a venous thrombus

Answer 12

Red thrombus; fibdin and red cells

Results in back pressure

Principally due to stasis and hypercoagulability

Question 13

What are some types of venous thromboebolism?

Answer 13

Limb DVT
Pulmonary embolism
Visceral Venous thrombosis
Intracranial venous thrombosis
Superficial thrombophlebitis

Question 14

What are risk factors for venous thrombosis?

Answer 14

Increasing age
Pregnancy
Hormonal therapy; COCP/HRT
Tssue trauma
Immobility
Surgery
Obesity
Systemic disease
FHx

Question 15

How is venous thrombosis diagnosed?

Answer 15

Prestest probability; Wells score, Geneva Score

lab testing; D-dimer

Imaging

Question 16

Describe doppler US

Answer 16

Compression ultrasonography

Contrast venography, CT venography, MRA

DVT: thrombosed vein enlarged, non-compressive, echogenic material may be seen

Question 17

What is the aim of management in venous thrombosis?

Answer 17

Prevent clot extension
Prevent clot embolisation
Prevent clot recurrence long term

Question 18

What drugs are used in venous thrombosis?

Answer 18

Anticoags;

• LMWH
• Coumarins (warfarin)
• DOACs

Thrombolysis only in selected cases; massive PE

Question 19

What is heritable thrombophilia and some types?

Answer 19

Inherited predisposition to venous thrombosis

Types;

• Factor V leiden and prothrombin common
• antithrombin deficiency, protein C/S deficiency rare

Question 20

What thrombophilia is screened for?

Answer 20

Limited to high risk heritable thrombophilia (antithrombin deficiency)

Screening asymptomatic family members not recommended

Question 21

Describe microvascular thrombus

Answer 21

Platelets and/or fibrin
Results in diffuse ischaemia
Principally in disseminated intravascular coagulation (DIC)

Question 22

Describe DIC

Answer 22

Disseminated intravascular coagulation

Occurs in; septicaemia, malignancy, eclampsia

Causes tissue ischaemia; gangrene, organ failure

Consumption of platelets and clotting factors lead to bleeding

Question 23

How is compartment syndrome treated?

Answer 23

If there is occlusive dressing;

• First line - remove dressing and analgesia (morphine usually)
• second line - fasciotomy if removal of dressing does not relieve pressures

If no occlusive dressing
- Fasciotomy

Amputation may be necessary if fasciotomy is ineffective

Question 24

What are complications of compartment syndrome?

Answer 24

Rhabdomyolysis

Question 25

Describe compartment syndrome

Answer 25

Increased interstitial pressure in closed osteofascial surface which inhibits blood supply