Deep Vein Thrombosis (DVT) & Pulmonary Embolism (PE)

Question 1

What is the difference between a thrombus and an embolus?

Answer 1

Thrombus: a blood clot which disrupts blood flow
Embolus: part of the thrombus breaks off and travels throughout the body, which can create blockages

Question 2

Virchow’s Triad consists of 3 factors which increase the risk of thrombosis. What are they?

Answer 2

1. Hyper-coagulability of blood: increased risk of thrombosis, e.g. cancer, thrombophelia
2. Vessel wall injury: surgery, inflammation
3. Stasis of blood: immobility, obesity, pregnancy

Question 3

What causes pleuritic chest pains (sharp pain when you breath) & haemoptysis (coughing blood) in PE?

Answer 3

It is due to reduced blood supply to the lungs.
Pulmonary infarction is a type of pleuritic chest pain occurring during an embolism.
Pneumonia can also have these symptoms.

Question 4

What are the symptoms of DVT?

Answer 4

1. Paralysis
2. Being Bedridden
3. Throbbing/swelling of the leg
4. Swollen veins
5. Cancer

Question 5

What are the symptoms of PE?

Answer 5

Same as DVT, plus:

1. Tachycardia
2. Leg pain/swelling of calf from a DVT
3. Shortness of breath
4. Coughing with/without blood

Question 6

What is a d-dimer?

Answer 6

It is a fibrin degradation product (a protein fragment) around the breakdown of a clot

Question 7

What is heparin and what is its mode of action?

Answer 7

It is an anticoagulant that prevents the clotting cascade

Prothrombin –>thrombin is inhibited so fibrin formation cannot occur.

Question 8

What is warfarin and what is its mode of action?

Answer 8

It is an anticoagulant that blocks vitamin K uptake + clotting factors.
This eventually leads to the same effects as heparin.

Question 9

What are the issues with taking warfarin?

Answer 9

1. More interactions
2. Requires monitoring
3. Long half life with a narrow therapeutic window
4. Drug doses is different for every individual

Question 10

What are some examples of DOAC’s and when is it used?

Answer 10

Direct Oral Anticoagulants (DOACS): Dabigatran, apixaban, rivaroxaban, edoxaban
They are used at the start of DVT/PE.

Question 11

What are the pro’s & con’s of using DOAC’s, compared to warfarin?

Answer 11

PRO’S:

1. Fewer interactions
2. Shorter half life
3. Less monitoring needed
4. Set dose

CON’S:

1. More expensive than warfarin
2. Less evidence around it
3. No reversal mechanism like warfarin

Question 12

What is thrombophelia and how can one prevent it?

Answer 12

It is when blood clots form too easily, increasing the risk of a DVT/PE.
Preventions can include: smoking cessation, stockings, early leg mobilisation/elevation (if bedridden), heparin in immobile patients, and surgery.