Thrombotic disorders Flashcards
(26 cards)
What are the elements of haemostasis?
- Primary haemostasis (primary plug formation)
- Blood coagulation
- Fibrinolysis (after clot has been made)
What is a thrombus?
- Clot arrising in the wrong place
What is a thromboembolism?
‘Movement of clot along a vessel’
What are the three elements of virchow’s triad?
- Stasis
- Hypercoagulability
- Vessel damage
What factors increase stasis?
- Bed rest
- Travel
What factors increase coagulability?
- Pregnancy
- HRT
- Malignancy
- Trauma
What factors increase vessel wall damage?
Atherosclerosis
Arterial thrombus
Why?
Where?
What?
- ‘White clot’~platelets and fibrin
- Results in ischaemia and infarction
- Principally secondary to atherosclerosis
What are some examples of arterial thrombus?
- Coronary thrombosis:
- MI Unstable angina
- Cerebrovascular thromboembolism:
- Stroke
- Transient ischaemia
- Peripheral embolism
- Limb ischaemia
RF for arterial thrombus?
- Age
- Smoking
- Sedentary lifestyle
- Hypertension
- Diabetes mellitus
- Obesity
- Hypercholesterolaemia
Management of arterial thrombus?
- Primary prevention
- Lifestyle modification
- Treatment of vascular risk factors
- Acute presentation
- Thrombolysis
- Antiplatelet/anticoagulant drugs
- Secondary prevention
Venous thrombus
Why?
Results in?
Which part of virchow’s triad?
- ‘Red thrombus’~fibrin and red cells
- Results in back pressure
- Principally due to stasis and hypercoagulability
Examples of venous thromboembolism?
- Limb deep vein thrombosis
- Pulmonary embolism
- visceral venous thrombosis
- intracranial venous thrombosis
- superficial thrombophlebitis
RF for venous thromboembolism?
- Increasing age
- Pregnancy
- Obesity
- HRT
- Tissue trauma
- Immobility
- Surgery: can be within last 3 months, and can include day case patients
- FH
Which systemic diseases can lead to VTE?
- Cancer
- Myeloproliferative Neoplasm (MPNs)
- Autoimmune disease
How can we make a diagnosis of VTE?
- •Pretest probability scoring
- –Wells score
- –Geneva score
- •Laboratory testing if pretest probability low
- –D-dimer
- •Imaging
What is the gold standard imaging for VTE?
- CT Pulmonary angiogram
What other imaging options are available for VTE?
- If have nuclear imaging available use V/Q scan - (need to have a normal CXR)
- Looking for mismatch between the images
What is the aim of management for VTE?
- Prevent clot extension
- Prevent clot embolisation
- Prevent clot recurrence in long term treatmenta
What drugs are used in the Mx of VTE?
- •Anticoagulants
- –LMWH
- –Coumarins (warfarin)
- –DOACs
- •Thrombolysis only in selected cases
- –Massive PE
What is heritable thrombophilia?
An inherited predisposition to venous thrombosis
What are the most common types of heritable thrombophilia?
- Factor V leiden
- Prothrombin G20210A
What factor does V leiden act on?
Acts on activated factor 5
[it’s literally in the name]
What are the clinical recommendations for people with hereditary thrombophilias?
- Majority are not predictive of recurrent event
- Screening of asymptomatic family members not recommended
- Limited thrombophilia screening: restricted to high risk heritable thrombophilia (antithrombin deficiency)
