Thrombotic Disorders Flashcards
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
bleeding
thrombosis
what are the elements of haemostasis?
- Primary haemostasis
- Blood coagulation
- Fibrinolysis
primary haemostasis is triggered by tissue damage which leads to what things?
- Vasoconstriction
- Platelet adhesion
- Platelet aggregation
Coagulation - Coagulation cascade activated leading to what?
- Insoluble fibrin formation
- Fibrin cross-linking (to form a stable clot)
what is involved in the process of fibrinolysis?
Plasmin is activated by the activation of plasminogen
Plasmin breaks down the fibrin network
what is a thrombus?
‘Clot arising in the wrong place’
what is a thromboembolism?
‘Movement of clot along a vessel’
Picture showing DVT that has moved to lungs cause pulmonary embolism
how can Virchow’s Triad lead to a thrombus?
If one of more is upset this can lead to thrombus generation
what are some examples of when one of the components of Virchows triad can be upset
what are the 3 main types of thrombosis?
- Arterial
- Venous
- Microvascular
what makes up a Arterial thrombus and what does it result in?
- ‘White clot’~ consisted mainly of platelets and fibrin
- Results in ischaemia and infarction
- Principally secondary to atherosclerosis
what are some Examples of arterial thromboembolism?
•Coronary thrombosis – can lead to:
- Myocardial Infarction
- Unstable angina
•Cerebrovascular thromboembolism:
- Stroke
- Transient ischaemia
•Peripheral embolism:
- Acute limb ischaemia
what are the risk factors for arterial thrombosis?
- Age
- Smoking
- Sedentary lifestyle
- Hypertension
- Diabetes mellitus
- Obesity
- Hypercholesterolaemia
Family history is also an important risk factor
what is the Management (of arterial thrombosis)?
•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)
what is venous thrombus made of, what is it due to and what does it result in?
- ‘Red thrombus’~ mainly composed of fibrin and red cells
- Results in back pressure
- Principally due to stasis and hypercoagulability
what are some examples of venous thromboembolism?
•Limb deep vein thrombosis
•Pulmonary embolism
- visceral venous thrombosis
- intracranial venous thrombosis
- superficial thrombophlebitis
what are the Risk factors for venous thrombosis
Stasis/hypercoagulability?
increasing age
pregnancy
hormonal therapy: COCOP/HRT
Tissue trauma
immobility
surgery
obesity
systemic disease
family history
Systemic disease and venous thrombosis:
what systemic diseases may be a risk factor for VTE?
- Cancer
- Myeloproliferative Neoplasm (MPNs)
- Autoimmune disease:
- Inflammatory bowel disease
- Connective tissue disease e.g SLE
- Antiphospholipid syndrome: arterial and venous thrombosis
how is a diagnosis of venous thrombosis made?
•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
what is a common modality for imaging in VTE?
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)
What are the Aims of management (in venousthrombosis)?
- Prevent clot extension
- Prevent clot embolisation
- Prevent clot recurrence in long term treatment
what Drugs are used to manage patients with venothromboembolism?
•Anticoagulants:
- LMWH
- Coumarins (warfarin)
- DOACs
•Thrombolysis only in selected cases:
- Massive PE
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)
Heritable conditions that can increase the individuals risk of venous thromboembolic events
how does Factor V Leiden work?
Drive towards thrombin generation and a fibrin clot generation
