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 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 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
how do Physiological anticoagulants work?
Direct blocking effect on thrombin
If antithrombin is deficient then thrombin generation continues and you have fibrin clot formation
what is DIC? who does it occur in and what does it cause?
- 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
