DVT + PE

Question 1

What are the two types of VTE? (Venous thrombo-embolic disease)

Answer 1

DVT- Thrombus formed mostly in the venous valve pockets, in area of stasis blood flow. PE- Thromboembolus travels up through the right side of the heart, blocking a vessel in the lung.

Question 2

What is distal and proximal vein thrombosis?

Answer 2

1. Proximal VT- DVT of the popliteal or femoral vein. proximal as they are closer to the heart.
2. Distal VT- DVT of the calves.

Question 3

Virchow’s triad can be a precursor to thrombosis. What is it?

Answer 3

• Endothelial injury - Circulatory stasis - Hypercoagulative state

Question 4

What are some exposing and predisposing risk factors for VTE?

Answer 4

1. Exposing surgery, trauma, acute medical illness, acute heart failure, acute respiratory failure, central venous catheterisation
2. Predisposing Previous VTE, Varicose veins, obesity, age, paralysis etc Cancer + inflammatory disease fall into both.

Question 5

What is provoked/unprovoked VTE?

Answer 5

1. Provoked- can be due to a reversible (eg trauma) or irreversible (cancer) cause.
2. Unprovoked- idiopathic, cause unknown. Higher recurrence rate of VTE in unprovoked.

Question 6

Common consequences of VTE?

Answer 6

• PE
• recurrent VTE
• Post thrombotic syndrome
• chronic thrombo-embolic pulmonary hypertension (CTEPH) - Reduced life quality.

Question 7

What is post-thrombotic syndrome (PTS)?

Answer 7

Long term complication of DVT. DVT induced damage to the valves and valvular reflux = venous hypertension. Significant disease needing long term treatment.

Question 8

What are some characteristics of PTS?

Answer 8

• Pain - Oedema - hyper-pigmentation - varicose collateral vein - eczema - venous ulceration

Question 9

What is CTEPH?

Answer 9

Serious complication of PE. Original embolic material replaced by fibrous tissue, incorporated into intima and media of arterial wall.

Results- occlusion, limiting blood flow through pulmonary arteries. Result- Right heart failure

Question 10

How does it present? what can it lead to?

Answer 10

Initially asymptomatic, with progressive dyspnoea and hypoxemia. Right heart failure frequent.

Question 11

How does D dimer work in VTE?

Answer 11

D-dimer: breakdown product of fibrin Test measures levels of fibrin to detect extent of thrombosis.

Low D dimer levels = DVT

Question 12

How does Wells score correspond with VTE?

Answer 12

Low- check d-dimer. no need of imaging

if - Mod/high- Imaging required

Question 13

What can a CXR and V/Q scan show for VTE?

Answer 13

CXR- cannot show PE (clots dont appear on cxr). can show pleural effusions/ infarcts.

V/Q scan- demonstrates mismatched perfusion defects. Useful in small peripheral PE.

High V/Q Ratio- Low Paco2, high Pao2

Alveolar dead space means- Low SaO2- Dsypnoea, tachypnoea

Question 14

What drugs are used for VTE?

Answer 14

• Anti coagulants: rivaroxaban, apixaban, Dabigatran -

Thrombolytics: Streptokinase -

Analgesics: paracetamol

Question 15

What do compression stockings do?

Answer 15

Apply pressure to the foot and legs, pushing blood upwards.

Prevents PTS- Post thrombotic syndrome

Question 16

What does an IVC filter do?

Answer 16

Cap externally applied on the inferior vena cava. Prevents any clot fomration and travelling up to form a PE. Used short term in patients who cant hanle anti coagulants Long term in people- Recurrent proximal DVT despite Anti coagulants