DVT

Question 1

Where can DVTs occur?

Answer 1

1. Proximal - popliteal, superficial femoral, deep femoral, common femoral, external iliac.
2. Distal - soleal, peroneal veins.

Question 2

What is a DVT?

Answer 2

Deep vein thrombosis - blood clot in a major deep vein in the leg, thigh, pelvis, or abdomen, which may result in impaired venous blood flow and consequent leg swelling and pain.

Question 3

What are the risk factors for DVT?

Answer 3

Age, pregnancy, synthetic oestrogen, trauma, surgery especially orthopaedic and pelvic, past DVT, cancer, obesity, immobility.

Question 4

What is this a presentation of?

Unilateral warm calf, tender, swelling, erythema, pitting oedema.

Answer 4

DVT

Question 5

What is the method of risk stratification in a suspected DVT?

Answer 5

DVT specific Wells score:

1. Active cancer (1)
2. Recently bedridden >3 days or major surgery in the last 12 weeks (1)
3. Paralysis, paresis or recent plaster immobilisation of affected leg (1)
4. Previously documented DVT (1)
5. Calf swelling >3cm more than contralateral leg (1)

Question 6

What is the process of diagnosing a DVT?

Answer 6

1. Calculate Wells score
2. If unlikely, d-dimer, if this is positive then USS.
3. If likely, d-dimer and USS.

Question 7

What is the management for a DVT?

Answer 7

1. FBC, PT, aPTT, LFTs, U&Es prior to anticoagulation.
2. Start treatment in proximal, only start treatment in distal if symptomatic or if risk factors present.
3. DOAC (dabigatran, enoxaparin) - 3 months if provoked, 6 months if unprovoked.
4. TED stockings

Question 8

What is the mechanism of action of heparin?

Answer 8

1. UFH activates antithrombin which inhibits factor Xa.

2. LMWH inhibits factor Xa

Question 9

What are the side effects of heparin?

Answer 9

1. Bleeding (less so with LMWH)
2. Injection site reactions
3. Heparin-induced thrombocytopenia

Question 10

What is the mechanism of action of warfarin?

Answer 10

Inhibits hepatic production of vitamin K dependent coagulation factors (2, 7, 9, 10).

Question 11

What is the main side effect of warfarin?

Answer 11

Bleeding

Question 12

What are the pharmaceutical and non-pharmaceutical interactions with warfarin?

Answer 12

1. NSAIDs, St John’s Wort, antihistamines, some antibiotics.

2. Cranberry juice/grapefruit, moderate alcohol, sudden diet change.

Question 13

What are the complications of a DVT?

Answer 13

1. Post-thrombotic stroke - chronic obstruction of venous outflow and/or destruction of venous valves causing venous hypertension.
2. Pulmonary embolism

Question 14

What is the advice for DVT and travel?

Answer 14

1. Compression stockings
2. Leg exercises
3. Increased water intake
4. Refrain from alcohol and caffeine
5. In high risk individuals - single dose LMWH may be considered.