Deep Vein Thrombosis

Question 1

Description:

Answer 1

A blood clot in the deep veins of the lower limbs, usually below the knee

Question 2

Aetiology/Risk Factors:

Answer 2

Risk Factors:

• Previous DVT
• Pregnancy and the oral contraceptive pill
• Malignancy
• Recent surgery
• Trauma
• Obesity
• Old Age
• Inherited thrombophilia (Factor V Leiden)

Question 3

Pathology:

Answer 3

Virchow’s Triad:

• Changes in the blood vessel wall = Endothelial damage
• Changes in the blood vessel constituents =Hypercoaguability
• Changes in the pattern of blood flow = Stasis/turbulence

A clot is made of:

• Red blood cells
• Platelets
• Fibrin

Question 4

Symptoms:

Answer 4

• Unilateral limb swelling
• Persisting discomfort
• Calf tenderness

Question 5

Signs:

Answer 5

• Warmth of the calfs
• Unilateral pitting oedema
• Redness due to erythema
• Prominent collateral veins

However may be clinically silent

Question 6

Complications:

Answer 6

• Pulmonary embolism

- Pulmonary hypertension

Question 7

Investigations:

Answer 7

• Wells Score for the pre-test probability
• D-dimer if low pre-test probability. (Negative d-dimer excludes a DVT)
• Compression ultrasound if d-dimer is positive or a high pre-test probability score (negative compression ultrasound excludes DVT)

Question 8

Treatment:

Answer 8

Aims of the treatment:

• Prevent clot extension
• Prevent clot embolisation
• Prevent recurrent clot

Anticoagulation is the main treatment:

• Low molecular weight heparin (parenteral)
• Warfarin (enteral)
• DOAC (e.g apxiaban - enteral, lower risk of major bleeding)

Question 9

Prevention of DVT in the hospital:

Answer 9

• Early mobilisation
• Anti-embolism stockings
• Thromboprophylaxis (can be pharmacological - decreases the risk of DVT and PE)