Venothromboembolism (W6) Flashcards
examples where blood clotting causes disease
DVT and PE
MI
stroke
atrial fibrillation with clot in left atrium
arterial occlusion of lower limb
what systems prevent clotting
healthy endothelium
anti-thrombins prevent thrombin formation
protein C and S inactivate clotting factors
fibrinolysis-plasmin breaks down fibrin
what breakdown product of fibrinolysis is used in diagnosis
D-dimer
what do platelets produce that activates further platelets
ADP, thromboxane A2
what inhibits thromboxane A2 synthesis
aspirin
2 types of tests for DVT?
proximal leg vein ultrasound
D-dimer
DVT investigation using wells score?
wells score 0 or 1 - D-dimer. positive then doppler ultrasound leg. negative then safety netting advice
wells score 2 or more - doppler ultrasound leg. negative then review in 5-7 days. positive then treat for DVT
DVT treatment?
apixaban (factor Xa inhibitor)
low molecular weight heparin (targets Xa and thrombin)
Virchow’s triad - what is this for and what are the 3 components
for thrombosis.
-stasis
-vessel wall injury
-hypercoagulability
what should you look for if someone has an unprovoked DVT
cancer
how do tumours cause hypercoagulability and vessel wall injury
release tissue-factor like molecules (activate coagulation cascade)
produce molecules that damage endothelium
pulmonary embolus investigations
CT pulmonary angiogram
PE presentation
breathlessness
pleuritic chest pain
cough
calf or leg swelling
less common - haemoptysis and syncope
PE presentation - things you’ll find when you examine the patient
tachycardia (including AF)
tachypnoea
calf or leg swelling
crackles or reduces breath sounds
elevated JVP (jugular venous pressure
PE treatment
treat for 3 months:
oral factor Xa inhibitor (apixaban, rivaroxaban) - standard
low molecular weight heparin followed by thrombin inhibitor/vitamin K agonist (dw about now)
