Venous Thrombosis Flashcards
most common areas of arterial thrombotic events
brain
heart
peripheral circulation
most common areas of venous thrombosis
lungs
legs
why do you get angina/claudication in atherosclerosis?
less O2 getting to tissues from narrowed vessels from the plaque
platelets are activated in arterial/venous thrombosis
venous
secondary haemostasis is more active in arterial/venous thrombosis
venous
main component of an arterial thrombosis
platelets
main component of a venous thrombosis
fibrin
Tx venous thrombosis
heparin (acutely)
warfarin (chronically)
NOACs
Tx arterial thrombosis
aspirin and other antiplatelets
why are you at increased risk of thrombosis in pregnancy
oestrogen pushes up production of clotting factors to stop bleeding AND
gravid uterus compressing BVs
DDx DVT
cellulitis
why do you get pleuritic chest pain in PE
infarcted edge of the lung wont allow it to slide during breathing as well
ECG changes of PE
S1Q3T3
S wave in lead 1
Q wave and T wave inversion in V3
name virchows triad for risk of VTE
vessel Wall - damaged valves
hypercoagulability - inc CFs
stasis - not moving around
“WH Smith”
risk of having another blood clot if youve had one before is _%
25
when is the highest time for developing VTE in oregnancy?
PUERPERIUM
primary haemostasis is affected in arterial thrombosis T or F
T, overdrive of the platelet plug
define thrombophilia
familial increased tendency to thrombose
mechanisms of thrombophilia
inc coagulation activity eg platelet/fibrin clot formation
decreased fibrinolysis
decreased anticoagulant activity
primary/secondary haemostasis is more commonly affected in thrombophilia
secondary
protein C releases what to switch off factor 5?
factor 5 leiden
factor 5 leiden deficiency causes a _ fold increase in VTE risk
5
factor 2 can also be called
prothrombin
causes of hereditary thrombophilias
F5L deficiency prothrombin mutation antithrombin deficiency protein C deficiency protein S
what substances switch off fibrin production
protein c
protein s
antithrombin
what symptoms would prompt you to consider hereditary thrombophilia screening?
venous thrombosis <45 yo
recurrent VTE
unusual VTE
FH of VTE/thrombophilia
Tx hereditary thrombophilia
risk avoidance
short term prophylaxis eg in pregnancy
short term anticoagulation
long term anticoagulation if recurrent events only
if you have 2 risk factors for VTE will your risk be much higher than it was with 1 or only a little?
a lot more
clinical features of APLS
recurrent thromboses
recurrent miscarriage
mild thrombocytopenia
pathogenesis APLS
change in beta 2 glycoprotein 1 which activates haemostasis and vessel wall abnormalities
Tx APLS
aspirin
warfarin
causes arterial and venous thrombi
how long should you anticoagulate for?
3 months if provoked
6 months to lifelong depending on risk factors
name drugs that can cause a DVT
hormonal eg HRT/COCP IV drug use high dose steroids antipsychotics in the elderly chemo drugs
most high risk surgery for DVT?
orthopaedic
why wouldnt you give warfarin prophylactically for surgery?
it takes a will for it to get to the therapeutic range
higher bleeding risk than LMWH
1st line anticoagulant for post-surgery prophylaxis for DVT/PE risk
rivaroxaban
first, second and third line anticoagulant for AF
- edoxaban
- apixaban
- warfarin
why wouldnt you use a DOAC in AF
end stage CKD
dialysis
what FBC value would suggest more of a production rather than production problem
all would be low
why does VWF disease cause prolonged APTT?
it carries around factor 8 so if its low factor 8 cant be carried around
APLS causes a prolonged PT/APTT
APTT (antibody on it prolongs it)
