Venous Thrombosis

Question 1

What is a VTE?

Answer 1

Involves a blood clot (thrombus) developing in the circulation, usually secondary to blood stagnation or hypercoagulable states

Question 2

When a thrombus develops in a deep vein, it is called a..

Answer 2

DVT

Question 3

What’s a PE?

Answer 3

Once a thrombus has developed, it can travel (embolise) from the deep veins, through the right side of the heart and into the lungs, where it becomes lodged in the pulmonary arteries

Question 4

If the patient has a septal defect in their heart, the thrombus can pass through to the ______ side of the heart and into the systemic circulation. If it travels to the brain, it can cause a large ______

Answer 4

If the patient has a septal defect in their heart, the thrombus can pass through to the left side of the heart and into the systemic circulation. If it travels to the brain, it can cause a large stroke

Question 5

Risk factors for DVT/PE

Answer 5

Immobility
Recent surgery
Long haul travel
Pregnancy
Hormone therapy with oestrogen
Malignancy
Polycythaemia
Systemic lupus erythematosus
Thrombophilia

Question 6

What are Thrombophilias?

Answer 6

Conditions that predispose patients to develop blood clots

Question 7

Give examples of Thrombophilias

Answer 7

Antiphospholipid syndrome
Factor V Leiden
Antithrombin deficiency
Protein C or S deficiency
Hyperhomocysteinaemia
Prothombin gene variant
Activated protein C resistance

Question 8

What does VTE prophylaxis?

Answer 8

Low molecular weight heparin (LMWH), such as enoxaparin

Anti-embolic compression stockings

Question 9

Contraindications to VTE prophylaxis

Answer 9

Active bleeding or existing anticoagulation with warfarin or a DOAC

Question 10

Contraindications to anti-embolic compression stockings

Answer 10

Peripheral arterial disease

Question 11

DVTs are almost always..

Answer 11

Unilateral

Question 12

Bilateral DVTs suggest..

Answer 12

Chronic venous insufficiency or heart failure

Question 13

What does the clinical picture show?

Answer 13

DVT

Question 14

The calf circumference is measured 10cm below the tibial tuberosity. __________ difference is significant

Answer 14

More than a 3cm

Question 15

Consider a ______________ (e.g., shortness of breath and chest pain) in patients with features of a DVT

Answer 15

Pulmonary embolism

Question 16

What is a Well’s score?

Answer 16

Predicts the risk of a patient presenting with symptoms having a DVT or PE. It includes risk factors (e.g., recent surgery) and clinical findings (e.g., unilateral calf swelling over 3cm greater than the other leg).

Question 17

The Wells score is used when considering deep vein thrombosis. The outcome decides the next step..

Answer 17

Likely: perform a leg vein ultrasound

Unlikely: perform a d-dimer, and if positive, perform a leg vein ultrasound

Question 18

_______________ is the usual first-line imaging investigation for a pulmonary embolism

Answer 18

CT pulmonary angiogram (CTPA)

Question 19

In DVT/PE, repeat negative ultrasound scans after 6-8 days if the patient has a..

Answer 19

Positive D-dimer and the Wells score suggests a DVT is likely

Question 20

Initial management of DVT/PE

Answer 20

Apixaban or rivaroxaban
LMWH (alternative)

Consider catheter-directed thrombolysis in patients with a symptomatic iliofemoral DVT and symptoms <14 days

Question 21

Long term coagulation of DVT/PE

Answer 21

DOACs - c.i severe renal impairment, antiphospholipid syndrome and pregnancy

Warfarin - 1st line in antiphospholipid syndrome

LMWH - 1st line pregnancy

Question 22

Long term anti-coagulation is continued for..

Answer 22

3 months with a reversible cause (then review)

3-6 months in active cancer (then review)

Long-term for unprovoked VTE, recurrent VTE or an irreversible underlying cause (e.g., thrombophilia)

Question 23

When are inferior vena cava filters used?

Answer 23

Used in those unsuitable for anticoagulation or where a PE has occurred whilst already on anticoagulation

Question 24

When patients have their first VTE without a clear cause, NICE recommend..

Answer 24

Reviewing the medical history, baseline blood results and physical examination for evidence of cancer

Question 25

In patients with an unprovoked DVT or PE that are not going to continue anticoagulation beyond 3-6 months, NICE recommend considering testing for..

Answer 25

Antiphospholipid syndrome Hereditary thrombophilias

Question 26

What is Budd-Chiari Syndrome?

Answer 26

Obstruction to the outflow of blood from the liver caused by thrombosis in the hepatic veins or inferior vena cava

Question 27

Budd-Chiari Syndrome is associated with..

Answer 27

Hypercoagulable states (e.g., myeloproliferative disorders)

Question 28

BCS presents with a classic triad of:

Answer 28

Abdominal pain Hepatomegaly Ascites

Question 29

___________ is the usual imaging investigation for establishing the diagnosis of Budd-Chiari syndrome

Answer 29

Doppler ultrasonography

Question 30

Tx for Budd-Chiari syndrome

Answer 30

Anticoagulation (LMWH and warfarin) Endovascular procedures (thrombolysis or angioplasty) Transjugular intrahepatic portosystemic shunt (TIPS) Liver transplant

Question 31

What is Virchow’s triad?

Answer 31

Stasis Vessel wall Hypercoagulability

Question 32

Potential mechanisms of thrombophilia

Answer 32

Increased coagulation activity – Platelet plug formation – Fibrin clot formation Decreased fibrinolytic activity Decreased anticoagulant activity

Question 33

Potential deficiencies in Hereditary thrombophilia

Answer 33

Factor V Leiden Prothrombin 20210 mutation Antithrombin deficiency Protein C deficiency Protein S deficiency

Question 34

______________ has a stronger risk factor for thrombosis than the hereditary thrombophilias

Answer 34

Acquired Thrombophilia - Antiphospholipid antibody syndrome

Question 35

Hypercoagulability is associated with..

Answer 35

Release of tissue factor, raised VWF and factor VIII

Question 36

Pathogenesis antiphospholipid antibodies

Answer 36

Conformational change in β2 glycoprotein 1 (a protein with unknown function in health) which leads to activation of both primary and secondary haemostasis and vessel wall abnormalities

Question 37

What is antiphospholipid syndrome?

Answer 37

Acquired disorder characterised by a predisposition to both venous and arterial thromboses, recurrent fetal loss and thrombocytopenia

Question 38

APS may occur as a primary disorder or secondary to other conditions, most commonly..

Answer 38

SLE

Question 39

Antiphospholipid syndrome causes a paradoxical rise in..

Answer 39

APTT - this is due to an ex-vivo reaction of the lupus anticoagulant autoantibodies with phospholipids involved in the coagulation cascade

Question 40

Venous/arterial thrombosis Recurrent miscarriages Livedo reticularis Pre-eclampsia, pulmonary hypertension

Answer 40

APS

Question 41

Ix for APS

Answer 41

Anticardiolipin antibodies Anti-beta2 glycoprotein I (anti-beta2GPI) antibodies Lupus anticoagulant Thrombocytopenia Prolonged APTT

Question 42

Mx for APS in primary thromboprophylaxis

Answer 42

Low-dose aspirin

Question 43

Mx for APS in secondary thromboprophylaxis

Answer 43

Initial venous thromboembolic events: lifelong warfarin with a target INR of 2-3 Recurrent venous thromboembolic events: lifelong warfarin; if occurred whilst taking warfarin then consider adding low-dose aspirin, increase target INR to 3-4 Arterial thrombosis should be treated with lifelong warfarin with target INR 2-3