VTE and anti-coagulant meds Flashcards
VTE prophylaxis
LMWH- enoxaparin
(contraindicated if active bleeding, warfarin or NOAC)
anti embolic stockings (contraindicated if significant peripheral arterial disease)
DVT presentation
unilateral calf or leg swelling dilated superficial veins tenderness to the calf oedema colour changes to the leg
measure the circumference of the calf 10cm below the tibial tuberosity
>3cm difference is signficiant
Diagnosis of DVT
- D dimer
- Ultrasound (repeat -ve USS after 6-8 days if there was a positive D dimer score)
PE: CTPA or V/Q scan
D- dimer specificity
95% sensitive but not specific for VTE
other causes of raised D dimer: Pneumonia Malignancy Heart failure Surgery Pregnancy
management of DVT
LMWH- immediately before confirming the diagnosis where DVT or PE is suspected and delay in scanning.
e.g enoxaparin, dalteparin.
long term anticoauglation
- warfarin (INR 2-3)
- NOAC
- LMWH
switching from LMWH to warfarin
continue LMWH for 5 days or until the INR is 2-3 for 24 hours (the longer option)
NOACs and DOACs
oral anticoagulants that are not warfarin
the alternative option does not require monitoring
‘direct acting oral anticoauglants’
e.g. apixaban, dabigatran, rivaroxaban
NOACs and DOACs
oral anticoagulants that are not warfarin
the alternative option does not require monitoring
‘direct acting oral anticoauglants’
e.g. apixaban, dabigatran, rivaroxaban
LMWH is first line VTE for pregnancy or cancer
VTE anticoauglation
3 months if there is an obvious reversible cause (then review)
Beyond 3 months if the cause is unclear, there is recurrent VTE or there is an irreversible underlying cause such as thrombophilia. This is often 6 months in practice.
6 months in active cancer (then review)
IVC filter
- devices inserted into the inferior vena cava
- filter the blood and catch any blood clots travelling from the venous system towards the heart and lungs.
- act like sieve, allowing blood to flow through whilst stopping larger blood clots.
- used in unusual cases of patients with recurrent PEs or those that are unsuitable for anticoagulation to prevent emboli traveling to the lungs.
investigating an unprovoked DVT
History and examination Chest X-ray Bloods (FBC, calcium and LFTs) Urine dipstick CT abdomen and pelvis in patients over 40 Mammogram in women over 40
test for antiphospholipid syndrome (antiphospholipid antibodies)
In patients with an unprovoked VTE with a family history of VTE they recommend testing for hereditary thrombophilias:
Factor V Leiden (most common hereditary thrombophilia) Prothrombin G20210A Protein C Protein S Antithrombin
What is a VTE?
common and fatal condition
thrombosis (clot) develops in circulation
- stagnation of blood
- hypercoagulable. state
DVT can mobilise to the right side of the heart > lungs > PE
if a patient has an ASD the blood clot can pass into the left side > brain > stroke
Virchow’s triad
stasis of blood flow
endothelial injury
hypercoagulability
types of clots
arterial thrombosis (platelt rich clot)
venous thrombosis (venous rich clot)
risk factors for arterial thrombosis
Smoking Hypertension Hypercholesterolaemia Diabetes Mellitus Obesity Family History Personal History
