DVT

Question 1

What is a deep vein thrombosis (DVT)?

Answer 1

A thrombus (clot) formed in deep venous circulation, resulting from venous thromboembolism

Question 2

Where do DVTs most commonly form?

Answer 2

In venous valve pockets and other sites of stasis, most commonly below the knee

Question 3

What are the two types of DVT?

Answer 3

1. Distal vein thrombosis
   = DVT of the calf, distal to the popliteal vein.
2. Proximal vein thrombosis
   = DVT of the popliteal or femoral vein, is more likely to embolise

Question 4

What are the common symptoms of DVT?

Answer 4

Calf warmth
Tenderness
Swelling
Erythema (unilateral)
Mild fever

Question 5

What are the common signs of DVT?

Answer 5

Pitting oedema
Localised swelling

Question 6

What investigations are used to diagnose DVT?

Answer 6

1 - D-dimer blood test
= useful for ruling out DVT in low-risk patients

2 - Ultrasound (Doppler)
= First-line diagnostic test if D-dimer or Wells score is high

Question 7

What is the first-line treatment for acute DVT?

Answer 7

Anticoagulation with DOACs (e.g., apixaban or rivaroxaban)

Question 8

What are second-line anticoagulants for DVT treatment?

Answer 8

1 - LMWH followed by dabigatran or edoxaban

2 - If dabigatran or edoxaban are contradicted then vitamin K antagonist (e.g., warfarin)

Question 9

What is the goal of secondary prevention for DVT?

Answer 9

Inhibit clot formation with long-term anticoagulation (e.g., warfarin, DOACs, or LMWH) for at least 3 months

Question 10

How does anticoagulation prevent DVT complications?

Answer 10

It inhibits the clotting cascade, preventing further clot formation but does not dissolve existing clots

Question 11

What is the duration of treatment with warfarin for patients with an unprovoked DVT/PE?

Answer 11

They should be treated with 6 months DOAC therapy

Question 12

What is the next best step in the management of a patient with suspected DVT with a Well’s score of more than 2?

Answer 12

Venous duplex ultrasound is the first line investigation

Question 13

How long should patients with a deep vein thrombosis be anticoagulated for?

Answer 13

Anticoagulation should continue for at least 3 months. In unprovoked DVT most patients carry on for 6 months

Question 14

What is the next best step in the management of a patient with suspected DVT with a Well’s score of less than 2?

Answer 14

D-dimer

Question 15

What is the target INR for patients with recurrence of VTE (Venous Thromboembolism) while on warfarin?

Answer 15

Note that for patients with recurrence of a VTE whilst on warfarin

= Target INR should be increased from 2-3 to 3-4

Question 16

What are the factors that increase the DVT Wells score by one point?

Answer 16

(1) Active cancer

(2) Paralysis, paresis, or recent plaster immobilisation of the legs

(3) Recently bedridden for 3+ days or major surgery in the last 12 weeks

(4) Localised tenderness along the deep venous system

(5) The entire leg is swollen

(6) Calf swelling at least 3 cm larger than the asymptomatic side

(7) Pitting oedema confined to the symptomatic leg

(8) Collateral superficial veins

(9) Personal history of DVT

Question 17

If a patient has a DVT Wells score of 2 or more, what is the next step in management?

Answer 17

(1) DVT is likely
= perform an ultrasound Doppler of the proximal leg veins within 4 hours.

(2) If not possible, do a D-dimer test, start interim anticoagulation, and arrange the Doppler within 24 hours

Question 18

What should be done if a patient has a Wells score of 1 or less?

Answer 18

(1) DVT is unlikely
= send a D-dimer.

(2) If results can’t be obtained within 4 hours, offer interim anticoagulation while awaiting results.

(3) If the D-dimer is positive, perform an ultrasound Doppler of the proximal leg veins.

(4) If negative, stop anticoagulation and consider an alternative diagnosis

Question 19

A 40-year-old woman presents to her GP with left leg swelling. She returned three days ago from a vacation. She is normally fit and well, with no medical conditions, and is physically active. She has visible superficial veins on the left leg and left calf swelling of 1 cm compared with the right. She has pitting oedema up to her shin on her left leg and is tender along the deep venous system.

A deep venous thrombosis (DVT) is suspected, and a Well’s score is calculated. What would her Well’s score be?

Answer 19

3