Venous thrombo-emboli (DVT and PE)

Question 1

Where is the most common location of a DVT?

Answer 1

Below/around calf (less concerning)

Anterior and posterior tibial veins (minor)

Question 2

Where is a more life-threatening location of a DVT?

Answer 2

Above calf (in thigh) eg in superficial femoral vein (major veins)
Occlusion here may impeded distal flow

Question 3

A PE occurs when a DVT embolises and lodges in the ______ _____ circulation

Answer 3

pulmonary artery

Question 4

What does Virchow’s triad consist of?

Answer 4

Hypercoagulability
Endothelial injury
Venous stasis

Question 5

What affects hypercoagulability of blood, increasing risk of DVT/PE?

Answer 5

Pregnancy
Combined oral contraceptive pill
Obesity
Antiphospholipid syndrome
Sepsis
DIC
Malignancy

Question 6

APS is an _____ disorder characterised by presence of ______ antibodies in the blood, with a tendency to develop blood clots. The antibodies target phospholipids and interfere with normal functioning and increase risk of abnormal blood clotting in veins and arteries.

Answer 6

autoimmune
antiphospholipid

Question 7

APS commonly causes _____ complications

Answer 7

pregnancy

Increased risk of placental thrombosis, impairing foetal development

Question 8

What are signs other than thrombi of APS?

Answer 8

Livedo reticularis (mottled skin discolouration)
Cognitive dysfunction, headaches, seizures, transverse myelitis
Heart valve abnormalities
Cardiomyopathy
Renal artery thrombosis and nephropathy

Question 9

What is transverse myelitis?

Answer 9

Neurological disorder characterised by inflammation of spinal cord causing weakness (below level of inflammation), sensory disturbances, pain, fatigue and bowel and bladder dysfunction.

Typically affects both sides of spinal cord

Unknown cause, thought to be autoimmune reaction idiopathically or following infection, MS or systemic autoimmune diseases.

Question 10

What affects endothelial integrity/injury and increases risk of DVT/PE?

Answer 10

Smoking
Trauma
Surgery

(Endothelium normally secretes anticoagulant but not if damaged)

Question 11

What affects venous stasis and increases risk of DVT/PE?

Answer 11

Immobility (long flights, after surgery)

Blood typically spreads out clotting factors with laminar flow but stasis leads to aggregation.

Question 12

PE causes ___ _____
Increased Peripheral vascular resistance means increased RV strain to overcome this leading to ____ _____ _____ and finally RV failure secondary to increased pulmonary pressure

Answer 12

Cor pulmonale
Right ventricle hypertrophy

Question 13

PE, pneumothorax and pneumonia all present with…

Answer 13

Pleuritic chest pain

Chest XR:
PE will look normal
Pneumonia and pneumothorax won’t!

Question 14

How would a patient with a DVT present?

Answer 14

Unilateral swollen calf with engorged leg veins
Warm and oedematous

Question 15

If complete occlusion of a large vein in DVT, what would you see?

Answer 15

Phlegmasia cerulea dolens = leg turns blue due to severe ischaemia

Question 16

A Wells score of more than _ indicates a DVT is likely

Answer 16

1
(Calf swelling 3cm or more than other leg = 1 point
Pitting oedema = 1 point)

Question 17

How is a DVT diagnosed?

Answer 17

If Wells score is less than 1 then do D-dimer test
If D-dimer raised or Wells score is 1+ then Duplex ultrasound (gold standard)

Question 18

How do you treat a DVT?

Answer 18

Same as a non-massive PE:

DOAC like Apixaban or rivaroxaban

If DOAC is contraindication eg renal impairment, then give LMWH

Mobilisation and compression stockings

Question 19

What is a differential diagnosis to a DVT?

Answer 19

Cellulitis (skin infection)
Tender, inflamed swollen calf with pronounced demarcation

Question 20

What organisms typically causes cellulitis?

Answer 20

Staph aureus and strep pyogenes

Question 21

How is cellulitis differentiated from DVT?

Answer 21

FBC shows leukocytosis (indicative of infection) with cellulitis but normal levels in DVT.
DVT will show D-dimer and duplex ultrasound will confirm.

Question 22

What are symptoms of a PE?

Answer 22

Sudden onset pleuritic chest pain
Dyspnoea
Possibly haemoptysis
Evidence of DCT (swollen calf and immobilisation history)

Tachycardia
Hypotensive
Raised JVP
Ankle oedema

Question 23

A Wells score of _ or more indicates a PE is likely

Answer 23

4
(eg. DVT evidence = 3 points
Tachycardia = 1.5 point)

Question 24

How is a PE diagnosed?

Answer 24

D dimer and CTPA (pulmonary angiogram)

ECG shows sinus tachycardia and/or:
S1Q3T3 = major sign of cor pulmonale

T wave inversion of anterior and inferior leads

New RBBB

Chest XR = normal

Question 25

What does S1Q3T2 mean?

Answer 25

A large S wave in lead 1 (ventricular depolarisation and contraction)

A Q wave in lead 3
An inverted T wave in lead 3

Indicates acute right heart strain possibly cor pulmonale or PE

Question 26

What is cor pulmonale?

Answer 26

Condition characterised by enlargement and dysfunction of the right ventricle as a result of pulmonary hypertension.

Right sided heart failure
Increased pressure in right side means RV becomes enlarged and weakened, impairing ability to pump blood.

Question 27

What is 1st line is the Wells PE score is 4 or lower?

Answer 27

D dimer test
If raised then do CTPA (gold standard)

Question 28

What is done if the Wells PE score is greater than 4?

Answer 28

CTPA (pulmonary angiogram)

Question 29

Why perform a D dimer test for diagnosing a PE?

Answer 29

Measure of clot burden, this small protein is released in blood when a blood clot is fibrinolysed

It is sensitive so rules PE in but is not specific as raised in many conditions so is not diagnostic

Question 30

What is treatment for a massive PE?

Answer 30

Thrombolytics : Alteplase (clot buster))

Question 31

What is treatment for a non-massive PE?

Answer 31

DOAC, 1st line = apixaban or Rivaroxaban

If contraindicated (eg renal impairment) then give LMWH