Thrombotic disorders Flashcards
3 elements of haemostasis
primary haemostasis
blood coagulation
fibrinolysis
primary haemostasis
vasoconstriction
platelet adhesion
platelet aggregation
thrombus
clot arising in the wrong place
thromboembolism
movement of a clot along a vessel
Virchow’s triad
stasis
hypercoagulability
vessel damage
Virchow’s triad and their causes
stasis - bed rest and travel
hypercoagulability - pregnancy and trauma
vessel damage - atherosclerosis
3 types of thrombosis
arterial
venous
microvasculature
what makes up an arterial thrombus?
white clot
platelets and fibrin
What does arterial thrombus result in?
ischaemia and infarction
what is arterial thrombus secondary to?
atherosclerosis
examples of arterial thromboembolism
MI, TIA, stroke, limb ischaemia
Risk factors for arterial thrombosis
age smoking obesity diabetes hypertension hypercholesterolaemia sedentary lifestyle
managing arterial thrombus
primary prevention - risk factors and lifestyle
thrombolysis and meds
secondary prevention
What makes up a venous thrombus?
red thrombus
fibrin and red cells
What is the main cause of venous thrombus?
stasis and hypercoagulability
venous thrombus examples
limb DVT
PE
also visceral, intracranial etc
risk factors for venous thrombosis
age obesity FH systemic disease COCP/HRT surgery immobility tissue trauma
systemic disease and venous thrombus
cancer
myeloproliferative neoplasm
auto-immune eg IBD, SLE
Pretest probability scoring for venous thrombus
Geneva score
wells score
When do you perform lab test for venous thrombus and what is this?
D-dimer
pre-test probability score low
Imaging used to diagnose venous thrombus
V/Q scan
doppler USS
CT pulmonary angiogram
aim of venous thrombus management
prevent clot extension and embolization
prevent further clots
venous thrombus drugs used
anticoagulants eg LMWH, warfarin and DOACs
thrombolysis?
Heritable thrombophilia
Inherited predisposition to venous thrombosis
common heritable thrombophilia
factor V leiden
prothrombin G20210A
Rare heritable thrombophilia
natural anti-coagulants
eg protein C+S, AT deficiency
What makes up a microvascular thrombus?
platelets and/or fibrin
What does microvascular thrombus principally occur in?
DIC
What is DIC?
diffuse systemic coagulation activation
What does DIC occur in?
septicaemia
malignancy
eclampsia
What does DIC cause?
thrombus, ischaemia, gangrene, necrosis
Why can DIC lead to bleeding?
consumption of platelets and clotting factors
