Deep Vein thrombosis

Question 1

What is a DVT?

Answer 1

A deep vein thrombosis (DVT) refers to the formation of a thrombus within the deep venous system, most often occurring in the veins of the leg but also in the pelvis and arm.

Question 2

What can happen if the thrombus becomes dislodged?

Answer 2

If this thrombus becomes dislodged, it becomes an embolus and can travel to the lungs causing a pulmonary embolism (PE)

Question 3

What are DVT and PEs examples of?

Answer 3

Venous thromboembolism

Question 4

What % of surgical patients are affected by DVTs?

Answer 4

25-50%

Question 5

Give the 3 broad factors of thrombosis risk according to Virchow’s triad:

Answer 5

1) stasis
2) vessel wall injury
3) hypercoagulability

Question 6

Give 5 instances where the blood may become more coagulable?

Answer 6

1) pregnancy
2) nephrotic syndrome
3) cancer
4) smoking
5) post-burn

Question 7

What can increase likelihood of stasis?

Answer 7

1. Immobility
2. Varicose veins
3. Obesity

Question 8

What can cause endothelial injury?

Answer 8

1. Physical trauma
2. Foreign devices
3. Hypertension
4. Bacterial infection

Question 9

Give 8 patient risk factors for DVTs:

Answer 9

1) obesity
2) previous DVT/PE
3) increasing age
4) immobility/ bed rest for 4> days
5) continuous travel for >3 hours in proceeding 4 weeks
6) contraceptive pill
7) varicose veins
8) pregnancy

Question 10

Give 8 diseases/ procedures that increase the risk of DVTs:

Answer 10

1) cancer
2) nephrotic syndrome
3) IBD
4) sickle cell anaemia
5) recent MI or stroke
6) cardiac/ respiratory failure
7) central venous catheter
8) trauma/ surgery to lower limbs

Question 11

Give 5 potential presentations of deep vein thrombosis:

Answer 11

1) leg pain
2) swelling, redness and warmth of leg
3) cyanotic discolouration if complete occlusion
4) mild fever
5) ulceration in chronic instances

Question 12

What % of DVTs are asymptomatic?

Answer 12

65%

Question 13

Give 3 DVT-associated examination findings:

Answer 13

1) pitting oedema
2) distention/ bulging of superficial veins
3) Homan’s sign (calf pain on sudden, passive dorsiflexion during knee extension - not very specific)

Question 14

Give 3 potential differential diagnoses for a red, painful, swollen leg:

Answer 14

1) cellulitis
2) venous eczema
3) ruptured Baker’s cyst

Question 15

What is a Baker’s cyst?

Answer 15

a popliteal cyst seen in pseudo-thrombophlebitis

Question 16

What is a pseudo-thrombophlebitis?

Answer 16

signs and symptoms of venous inflammation in the absence of a thrombophlebitis region

Question 17

What score system is used to estimate the risk of DVT?

Answer 17

Well’s score

Question 18

What score on the Well’s Score indicates ‘likely’ chance of a future DVT?

Answer 18

2 or more points

Question 19

What lab investigation should be carried out first when suspecting a DVT?

Answer 19

Quantitative D-Dimer Level

Question 20

How does a D-Dimer blood test help diagnose DVT?

Answer 20

D-Dimer is a degradation product of fibrin which is formed by blood clots

Question 21

What investigation should be carried out if a D-Dimer test comes back positive to finalise a diagnosis of DVT?

Answer 21

Proximal Duplex Ultrasound

Question 22

Give two ultrasound signs that indicate DVT:

Answer 22

1) inability to compress the lumen of the vein using the ultrasound transducer
2) reduced flow in vein

Question 23

Give the two main categories of DVT management:

Answer 23

1. Anticoagulation
2. Procedures

Question 24

What is the name of the minor surgery that uses a catheter to deliver anticoagulants to the thrombus?

Answer 24

catheter directed thrombolytic therapy

Question 25

What is the name of the surgery used for patients with recurrent DVTs in order to prevent embolization?

Answer 25

inferior vena cava filter fitting

Question 26

What can patients wear on their legs to reduce risk of DVT?

Answer 26

below knee graduated compression stockings

Question 27

What are the 4 red flags for a PE?

Answer 27

Sudden-onset shortness of breath
Tachycardia
Haemoptysis
Chest pain (usually pleuritic)