Deep Vein Thrombosis and Pulmonary Embolism

Question 1

What are the 3 parts of Vichow’s triad?

Answer 1

Changes to vessel wall - damage due to atherosclerosis

Changes to blood flow - stasis due to being bed bound or travel (on planes)

Changes to vessel constituents - hypercoagubility due to trauma or pregnancy

Question 2

What is a thromboembolism?

Answer 2

Movement of a clot along a vessel causing an embolism

Question 3

What are the differences between venous and arterial thrombi?

Answer 3

Venous:
Red thrombus made of fibrin and RBCs
Results in back pressure (of veins)
Mainly due to stasis and hypercoagubility

Arterial:
White thrombus made of fibrin and platelets
Results in ischaemia and infarction
Mainly due to atherosclerosis - vessel damage

Question 4

Examples of venous thromboembolisms?

Answer 4

Limb DVT
Pulmonary embolism
Visceral venous thrombosis
Intracranial thrombosis

Question 5

What are the symptoms and signs of a DVT?

Answer 5

Unilateral limb swelling
Persisting discomfort
Calf tenderness
Warmth
Redness

It can be clinically silent though

Question 6

What is the initial diagnostic test for DVT?

Answer 6

Clinical assessment and a pretest probability score known as the wells score

If high - imaging
If low next test

Question 7

What is the second test if the pre-test probability score is low?

Answer 7

Blood test looking for D-diamers

Question 8

What imaging is used and when would it be used?

Answer 8

Compression USS if a positive D-dimer test or a high test score

Question 9

Long term consequences of a DVT?

Answer 9

Post thrombotic syndrome happens to 20-60% of patients within 2 years of a DVT

Causes:

swelling,
discomfort,
pigmentation
ulceration in most severe form

Question 10

Signs of a pulmonary embolism?

Answer 10

Pleuritic chest pain
Dyspnoea
Haemoptysis
Tachycardia
Plural rub heard on auscultation

Question 11

Signs of a massive PE?

Answer 11

Severe dyspnoea of sudden onset
Collapse
Central cyanosis
Tachycardia
Raised JVP

Question 12

Can a massive PE cause sudden death?

Answer 12

Yes

Question 13

Diagnosis of a PE?

Answer 13

Same steps as a DVT but imaging used is:

Isotope V/Q scan
CT pulmonary angiogram

Question 14

Long term consequences of a PE?

Answer 14

Most fully recover

Can cause pulmonary hypertension

Question 15

Treatment aims for a venous thromboembolism (VTE) event?

Answer 15

A VTE comprises a DVT and a PE

Aims are to prevent clot extension and embolism and prevent recurrence of a colt

Question 16

What types of medical therapy is used?

Answer 16

Antocoagulants

Thrombolysis

Question 17

What are the parenteral (non oral) options of anticoags?

Answer 17

Unfractionated heparin

LWMH

Question 18

What is the enteral (oral) options?

Answer 18

Warfarin

Direct oral anticoags

Question 19

When is thrombolysis used?

Answer 19

Massive PE

Question 20

If patient pregnant what drugs should we not use and what one is best to use?

Answer 20

Thrombolysis rarely used during pregnancy caused VTEs as its reserved for massive PEs

Can’t use warfarin as it is teratogenic - harms development of baby

Use LWMH

Question 21

How would we prevent a VTE in a hospital setting?

Answer 21

Early mobilisation to keep patient moving and stopping stasis of flow

Other mechanical or pharmcological methods of prophylaxis