DVT Flashcards
What does DVT stand for?
Deep vein thrombosis.
What is DVT?
Development of a 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.
What does VTE stand for?
Venous thromboembolism.
VTE includes what 2 conditions?
2/3 of VTE cases are DVT, and 1/3 are PE.
What is the epidemiology of a DVT?
· Incidence goes up with age.
· Incidence is slightly higher in women.
· Incidence is higher in black people, and lower in Hispanic and Asian people.
· Frequent flyers.
What is the pathophysiology of a DVT?
· Most clots in the deep venous system of the leg begin to form just above and behind a venous valve.
· Anatomical characteristics of the soleal vein plays a big role:
- It has no functioning valves.
- This causes rapid propagation and embolism.
· A clot might occlude the entire lumen, but is more commonly located on 1 peripheral aspect of the lumen.
· Many DVTs arise in the calf veins.
What do patients usually die of when they have a DVT?
From a PE or a major haemorrhage from anticoagulation therapy.
What are the 3 factors that individually, or together, lead to blood clots are?
Virchow’s triad:
- Vessel injury.
- Venous stasis.
- Activation of the clotting system.
What is the aetiology of a DVT?
· Most patients either develop DVT after a trigger that leads to coagulation, or they have an imbalance (genetic) in their coagulation system.
· There’s a clear association between DVT and the risk factors.
· The absence of these risk factors renders the DVT or being idiopathic or unprovoked.
List the potential risk factors of a DVT?
· Medical hospitalisation within the past 2 months.
· Major surgery within 3 months.
· Active cancer.
· Lower-extremity trauma.
· Increasing age.
· Pregnancy.
· Obesity.
· Factor V Leiden, protein C, S, prothrombin or anti-thrombin deficiency.
· Medical comorbidities.
· Recent long-distance air travel.
· Use of specific drugs such as oestrogen-containing oral contraceptives.
What are the common signs and symptoms of a DVT?
· Calf swelling. · Localised pain. · Asymmetric oedema. · Collateral superficial veins. · Swelling of the entire leg.
What investigations would you request if you suspected a patient had a DVT?
· Wells' clinical probability tool. · Quantitative D-dimer level. · Venous duplex ultrasound. · INR and APTT. · Urea and creatinine. · LFTs. · FBC. · CT Abdomen and pelvis with contrast.
Why are urea and creatinine levels measured?
For dose adjustment of anticoagulants if renal impairment.
Why might a CT abdomen and pelvis with contrast be performed?
For visceral and deep veins of abdomen and pelvis.
Suggest some differentials.
· Cellulitis. · Calf muscle/Achilles' tendon tear. · Calf muscle haematoma. · Ruptured popliteal cyst. · Pelvic/thigh mass/tumour compressing venous outflow of the leg.
