Thrombotic Disorders

Question 1

Haemostasis is a fine balance and if there is a dysregulation of one or more components then complications that can arise is _________ or _________ at the other end of the spectrum

Answer 1

bleeding

thrombosis

Question 2

what are the elements of haemostasis?

Answer 2

• Primary haemostasis
• Blood coagulation
• Fibrinolysis

Question 3

primary haemostasis is triggered by tissue damage which leads to what things?

Answer 3

• Vasoconstriction
• Platelet adhesion
• Platelet aggregation

Question 4

Coagulation - Coagulation cascade activated leading to what?

Answer 4

• Insoluble fibrin formation
• Fibrin cross-linking (to form a stable clot)

Question 5

what is involved in the process of fibrinolysis?

Answer 5

Plasmin is activated by the activation of plasminogen

Plasmin breaks down the fibrin network

Question 6

what is a thrombus?

Answer 6

‘Clot arising in the wrong place’

Question 7

what is a thromboembolism?

Answer 7

‘Movement of clot along a vessel’

Picture showing DVT that has moved to lungs cause pulmonary embolism

Question 8

how can Virchow’s Triad lead to a thrombus?

Answer 8

If one of more is upset this can lead to thrombus generation

Question 9

what are some examples of when one of the components of Virchows triad can be upset

Answer 9

Question 10

what are the 3 main types of thrombosis?

Answer 10

• Arterial
• Venous
• Microvascular

Question 11

what makes up a Arterial thrombus and what does it result in?

Answer 11

• ‘White clot’~ consisted mainly of platelets and fibrin
• Results in ischaemia and infarction
• Principally secondary to atherosclerosis

Question 12

what are some Examples of arterial thromboembolism?

Answer 12

•Coronary thrombosis – can lead to:

• Myocardial Infarction
• Unstable angina

•Cerebrovascular thromboembolism:

• Stroke
• Transient ischaemia

•Peripheral embolism:

• Acute limb ischaemia

Question 13

what are the risk factors for arterial thrombosis?

Answer 13

• Age
• Smoking
• Sedentary lifestyle
• Hypertension
• Diabetes mellitus
• Obesity
• Hypercholesterolaemia

Family history is also an important risk factor

Question 14

what is the Management (of arterial thrombosis)?

Answer 14

•Primary prevention:

• Lifestyle modification
• Treatment of vascular risk factors

•Acute presentation:

• Thrombolysis
• Antiplatelet/anticoagulant drugs

•Secondary prevention (focused on the treatment of identified risk factors)

Question 15

what is venous thrombus made of, what is it due to and what does it result in?

Answer 15

• ‘Red thrombus’~ mainly composed of fibrin and red cells
• Results in back pressure
• Principally due to stasis and hypercoagulability

Question 16

what are some examples of venous thromboembolism?

Answer 16

•Limb deep vein thrombosis

•Pulmonary embolism

• visceral venous thrombosis
• intracranial venous thrombosis
• superficial thrombophlebitis

Question 17

what are the Risk factors for venous thrombosis
Stasis/hypercoagulability?

Answer 17

increasing age

pregnancy

hormonal therapy: COCOP/HRT

Tissue trauma

immobility

surgery

obesity

systemic disease

family history

Question 18

Systemic disease and venous thrombosis:

what systemic diseases may be a risk factor for VTE?

Answer 18

• Cancer
• Myeloproliferative Neoplasm (MPNs)
• Autoimmune disease:
• Inflammatory bowel disease
• Connective tissue disease e.g SLE
• Antiphospholipid syndrome: arterial and venous thrombosis

Question 19

how is a diagnosis of venous thrombosis made?

Answer 19

•Pretest probability scoring:

• Wells score
• Geneva score

•Laboratory testing if pretest probability low:

• D-dimer

•Imaging

Lab testing is appropriate if the patients pretest probability score is low and if that’s negative then you can exclude DVT

If person has low pretest probability but a positive d-dimer then they require imaging

Patients with high pretest probability got straight to imaging

Question 20

what is a common modality for imaging in VTE?

Answer 20

doppler US (Common modality for imaging are doppler US for upper and lower limb veins)

Ventilation/Perfusion scan (V/Q) - This image shows in perfusion image that the right lower lung is well perfused so the person has bilateral pulmonary embolism

CT Pulmonary Angiogram (Regarded as a gold standard for pulmonary embolism)

Question 21

What are the Aims of management (in venousthrombosis)?

Answer 21

• Prevent clot extension
• Prevent clot embolisation
• Prevent clot recurrence in long term treatment

Question 22

what Drugs are used to manage patients with venothromboembolism?

Answer 22

•Anticoagulants:

• LMWH
• Coumarins (warfarin)
• DOACs

•Thrombolysis only in selected cases:

• Massive PE

Question 23

what are examples of Heritable thrombophilia?

(Thrombophilia is a condition in which there’s an imbalance in naturally occurring blood-clotting proteins, or clotting factors. This can put you at risk of developing blood clots)

Answer 23

Heritable conditions that can increase the individuals risk of venous thromboembolic events

Question 24

how does Factor V Leiden work?

Answer 24

Drive towards thrombin generation and a fibrin clot generation

Question 25

how do Physiological anticoagulants work?

Answer 25

Direct blocking effect on thrombin If antithrombin is deficient then thrombin generation continues and you have fibrin clot formation

Question 26

what is Microvascular thrombus?

Answer 26

* Involved Platelets and/or fibrin * Results in diffuse ischaemia * Principally in Disseminated Intravascular Coagulation [DIC] Most commonly seen in very unwell patients in intensive care

Question 27

what is DIC? who does it occur in and what does it cause?

Answer 27

* Diffuse systemic coagulation activation * Occurs in: - Septicaemia - Malignancy - eclampsia •Causes tissue ischaemia - Gangrene - organ failure * Consumption of platelets and clotting factors leading to bleeding * Activation of coagulation leading to microvascular thrombosis deposition

Question 28

Summary: * \_ main types of thrombosis * Different ____ factors for each * Varying ____________ \_\_\_\_\_\_\_\_ depending on type of clot

Answer 28

3 risk management strategies