Deep Vein Thrombus (DVT)

Question 1

DVT is caused by the partial or total occlusion of which vein(s)

Answer 1

The deep vein(s)

Question 2

What deep veins are commonly occluded in DVT

Answer 2

Commonly affects the lower limbs but can affect any deep vein e.g. thigh, pelvis or abdomen

Question 3

DVT is commonly seen alongside what other condition

Answer 3

Pulmonary embolism (PE)

Question 4

DVT is rarely life threatening but it can when can it become life threatening

Answer 4

It can cause pulmonary embolism (PE)

Question 5

Describe how the DVT can cause a PE

Answer 5

DVT occurs when a thrombus forms in the deep veins

an emboli from the thrombus of the deep veins can travel to the right side of the heart and into the lungs where it becomes lodged in the pulmonary arteries causing the PE

Question 6

What causes Venous thromboembolism (VTE)

Answer 6

Occurs as a result of a clot (thrombi) developing in the circulation

Question 7

Venous thromboembolism (VTE) encompasses two conditions.

Name the two conditions?

Answer 7

Pulmonary embolism (PE)

Deep vein thrombosis (DVT)

Question 8

Name some of the risk factors for DVT

Answer 8

Active cancer

Trauma

Major surgery

Hospitalisation

Immobilisation

Pregnancy

Oral contraceptive use

NOTE: DVT can be unprovoked (idiopathic) and occur in the absence of any identifiable risk factors

Question 9

What are some of the clinical features of DVT

Answer 9

Almost always unilateral

Asymmetrical leg swelling

Unilateral leg pain

Dilation or distension of superficial veins

Red or discoloured skin

Can also be asymptomatic

Question 10

Define Thrombophilias

Answer 10

Refers to conditions that predispose patients to develop blood clots.

Question 11

Give an example of a Thrombophilias

Answer 11

Antiphospholipid syndrome

Antithrombin deficiency

Protein C or S deficiency

Question 12

What is the Probability Tool for PE/VTE

Answer 12

Wells Score

Question 13

When is the Wells Score used

Answer 13

Used to predict the likelihood of a DVT/PE

Question 14

When interpretating the Wells Score.

A score of what makes a DVT likely

Answer 14

Wells Score 2 or more

Question 15

When interpretating the Wells Score.

A score of what makes a DVT unlikely

Answer 15

1 or less

Question 16

Name some of the components of the Wells Score

Answer 16

Active cancer

Paralysis, paresis or recent plaster immobilisation of the lower extremities

Recently bedridden for >3 days or major surgery within 12 weeks

Localised tenderness along the distribution of the deep venous system

Swelling of entire leg

Calf swelling (>3 cm larger than asymptomatic side)

Pitting oedema confined to the symptomatic leg

Prominent superficial veins (non-varicose)

Previously history of DVT or PE

An alternative diagnosis is at least as likely as DVT

Question 17

What are the two key investigations for DVT

Answer 17

Doppler ultrasound

D-dimer (although not always needed)

Question 18

When is the doppler ultrasound used in investigating DVT

Answer 18

Wells score DVT likely = Doppler ultrasound done first without the need for a D-dimer first

Wells score DVT unlikely = require D-dimer first and only if that comes back positive should they undergo a doppler ultrasound

Question 19

If a doppler ultrasound is unable to complete within 4 hours of DVT suspicion. What should be given whilst they await the scan?

Answer 19

Interim anticoagulation

Question 20

Wells score likely

Initialy scan negative

d-dimer positive.

What is the next stage in investigating DVT?

Answer 20

Interim anticoagulation should be stopped and a repeat proximal leg vein ultrasound in 6-8 days

Question 21

Patient has a:

Wells score likely

Initialy scan negative

d-dimer positive

The next step is stopping interim anticoagulation and repeating proximal leg vein ultrasound when?

Answer 21

6-8 days

Question 22

For patients with a Well score likely.

What is the next step in investigating DVT

Answer 22

Ultrasound (if available within 4 hours)

If over 4 hours, give interim anticoagulation whilst they await investigations

Question 23

For patients with a Well score unlikely.

What is the next step in investigating DVT

Answer 23

D-dimer

Question 24

D-dimer is an important investigation for DVT.

At what stage is D-dimer used

Answer 24

Used when the Wells score DVT unlikely or if the initial ultrasound scan is negative

Question 25

How specific and sensitive is d-dimer in DVT

Answer 25

Highly sensitive but not specific i.e. can reliably exclude VTE but cannot confirm it

Question 26

Venous thromboembolism (VTE) is a cause of a raised d-dimer however it is not the only cause. Name some other conditions that can cause a raised d-dimer

Answer 26

Pneumonia Malignancy Heart failure Surgery Pregnancy

Question 27

Wells score likely Doppler Ultrasound negative What is the next step in investigating DVT

Answer 27

Interim anticoagulation should be stopped and a repeat proximal leg vein ultrasound in 6-8 days

Question 28

Wells score unlikely D-dimer negative What is the next step in investigating DVT

Answer 28

Unlikely DVT Think other diagnosis

Question 29

Wells score unlikely D-dimer positive What is the next step in investigating DVT

Answer 29

Doppler ultrasound

Question 30

What is the cornerstone treatment in the initial management of DVT

Answer 30

Anticoagulation Should be started immediately in patients where: * DVT or PE is suspected * There is a delay in getting doppler ultrasound scan

Question 31

In most cases what is the anticoagulant of choice for the immediate management of DVT

Answer 31

Direct oral-acting anticoagulants (DOAC) e.g. apixaban or rivaroxaban

Question 32

After initial management, anticoagulant therapy is required to continue for a period of time to prevent future DVT/PE. What are the anticoagulation options for these patients

Answer 32

DOAC Low molecular weight heparin (LMWH) Vitamin K antagonists i.e. warfarin

Question 33

After initial management, anticoagulant therapy is required to continue for a period of time to prevent future DVT/PE. What is the anticoagulant used in the majority of cases

Answer 33

DOACs as it does not require monitoring

Question 34

What is the first-line anticoagulant in pregnancy [managing DVT]

Answer 34

Low molecular weight heparin (LMWH)

Question 35

What is the first-line anticoagulant in antiphospholipid syndrome [managing DVT]

Answer 35

Warfarin

Question 36

After initial management, anticoagulant therapy is required to continue for a period of time to prevent future DVT/PE. What is the duration of this therapy?

Answer 36

3 months – for those with reversible cause Beyond 3 months (typically 6 months) – if the cause is unclear, recurrent VTE, irreversible cause 3-6 months – active cancer

Question 37

After initial management, anticoagulant therapy is required to continue for a period of time to prevent future DVT/PE. What is the duration of this therapy if there is a reversible cause of the DVT

Answer 37

3 months

Question 38

After initial management, anticoagulant therapy is required to continue for a period of time to prevent future DVT/PE. What is the duration of this therapy if there is a cause is unclear, recurrent VTE, irreversible cause

Answer 38

Beyond 3 months (typically 6 months)

Question 39

After initial management, anticoagulant therapy is required to continue for a period of time to prevent future DVT/PE. What is the duration of this therapy for those with active cancer

Answer 39

6 months

Question 40

What is a complication of DVT

Answer 40

Post-thrombotic syndrome Presence of chronic swelling, pain and skin discoloration. In severe cases it can lead to ulcers and gangrene.