DVT and PE

What is a venous thrombus?

A clot formed mainly of fibrin.

Define an embolus.

A part of a thrombus that has broken off and is traveling through the blood vessel.

What is Deep Venous Thrombosis (DVT)?

The formation of a blood clot in a deep vein, typically in the lower limbs.

Where are the most common sites for DVT?

Lower limbs (calf veins, popliteal vein, femoral vein) and pelvis.

What is below knee DVT?

DVT involving calf and popliteal veins.

What is extensive DVT?

DVT that extends from the lower limbs to involve iliac veins and inferior vena cava.

What increases the risk of pulmonary embolism?

More extension of DVT.

Name one mechanism of venous thrombosis according to Virchow's triad.

Slow circulation (decreased rate of blood flow).

What are some conditions that can cause slow circulation?

Heart failure, shock, extensive myocardial infarction, prolonged immobilization, dehydration.

What is one cause of endothelial injury?

Indwelling venous catheters.

List two risk factors for hypercoagulability.

Pregnancy and oral contraceptive pills.

What is the classic symptom of DVT?

Unilateral lower limb swelling

What does Homans' sign indicate?

Pain in the posterior calf upon dorsiflexion of the foot.

What serious complication can arise from DVT?

PE

What characterizes phlegmasia cerulea dolens?

Severe edema, cyanosis, and tight skin.

What is the best treatment for phlegmasia cerulea dolens?

Urgent fasciotomy.

What is post-phlebitis syndrome?

A late complication of DVT characterized by leg pain, itching, and edema.

How can lymphedema be differentiated from DVT?

Lymphedema presents with non-pitting edema affecting lymphatic vessels.

What does a positive D-dimer indicate?

Ongoing thrombosis.

What is the best initial diagnostic investigation for DVT?

Doppler Ultrasonography (compression ultrasound).

What is pulmonary embolism (PE)?

The occlusion of pulmonary arteries by thrombi originating from elsewhere, typically from DVT.

What is the annual incidence of PE worldwide?

1 in 1000 people

What percentage of people diagnosed with acute PE die within 90 days?

20%.

What is the most common cause of death in PE?

Acute right ventricular failure.

What type of pulmonary embolism arises from DVT?

Thrombotic pulmonary embolism.

Name a type of non-thrombotic pulmonary embolism

Air embolism

What is the triad of symptoms for PE? What are the signs of PE?

Dyspnea, chest pain, and cough/hemoptysis. Tachycardia, tachypnea, and hypoxia.

What is the simplified Wells score for PE?

≤4 points = PE unlikely; >4 points = PE likely.

What is the role of D-dimer in PE diagnosis?

It can exclude the diagnosis when negative in low- or intermediate-risk patients.

What does ABG show in PE?

Hypoxemia and hypocapnia (respiratory alkalosis)

What ECG changes may indicate PE?

Tachycardia and S1Q3T3 pattern.

What is the gold standard for diagnosing PE?

CT pulmonary angiography.

What is the first-line treatment for DVT and PE?

Anticoagulants

Name a direct oral anticoagulant (DOAC).

Rivaroxaban , Apixaban or Edoxban

What is the recommended dose for low-molecular-weight heparin (Clexane)?

1 mg/kg BID.

What is the target INR for warfarin therapy?

2-3

How long is the recommended therapy duration for a first episode of above-knee DVT?

3-6 months

list 2 thrombolytic therapy and what are they indicated for?

streptokinase and alteplase, Massive PE complicated by hemodynamic instability

What is the purpose of an IVC filter?

For DVT and PE patients with contraindications for anticoagulants.

What imaging sign indicates decreased perfusion in PE?

Westermarck sign.

What does the Hampton Hump sign indicate?

Wedge-shaped opacity due to pulmonary infarction.

What can cause fat embolism?

Fractures or surgery involving long bones.

What is a common cause of septic embolism?

Infective endocarditis in IV drug users.

What are the consequences of chronic thromboembolic pulmonary hypertension (CTEPH)?

Long-standing obstruction of distal pulmonary arteries

What is the risk of embolization with DVT at or above the popliteal vein?

Higher risk compared to below-knee DVT.

What is the management for patients with likely PE and negative D-dimer?

Imaging investigations like CT pulmonary angiography.

What is the significance of elevated serum BNP in PE?

Indicates increased risk of cardiac arrest and death.

What does a negative duplex ultrasound indicate?

Exclusion of DVT

What is a potential sign of right ventricular failure in PE?

Congested neck veins (high JVP).

When should anticoagulant treatment be started in suspected PE cases?

Immediately when there is a high suspicion or probability of PE, without waiting for imaging results.

What is the duration of therapy recommended for recurrent episodes of DVT?

Lifelong anticoagulation therapy.

What is the primary surgical treatment for massive PE when thrombolytic therapy is contraindicated or has failed?

Pulmonary embolectomy or thrombectomy.

What are the indications for using a thrombolytic agent like alteplase in PE treatment?

Severe hypotension or shock due to massive pulmonary embolism.