Deep Vein Thrombosis (DVT) Flashcards
what is a DVT
DVT is the development of a thrombus in a major deep vein in the leg, thigh, pelvis, or abdomen.
main complication of DVT
thromboembolism (most serious being a pulmonary embolism)
what can slight alterations in coagulation lead to
bleeding and thrombosis
causes of DVT
virchows triad
what is virchows triad?
vessel injury, venous states and activation of the clotting system
ultimately, what causes a DVT
patients who develop DVT typically experience a trigger that leads to blood coagulation (e.g., surgery or trauma that activates the coagulation system), prolonged immobility that leads to stasis, or medications or illnesses (e.g., cancers, antiphospholipid syndrome) that can stimulate clotting
do genetic factors have a play in the development of a DVT
yes,
susceptibility to thrombosis as well as factor mutations and deficiencies are bound to genetic factors
which operations raise concerns regarding a DVT
orthopaedic
presenting symptoms (history and exam)
calf swelling, asymmetrical oedema, localised pain, positive Wells score, prominent superficial veins
what is the Wells score
Active cancer (patient either receiving treatment for cancer within the previous 6 months or currently receiving palliative treatment) 1
Paralysis, paresis, or recent cast immobilization of the lower extremities 1
Recently bedridden for ≥ 3 days, or major surgery within the previous 12 weeks requiring general or regional anesthesia 1
Localized tenderness along the distribution of the deep venous system 1
Entire leg swelling 1
Calf swelling at least 3 cm larger than that on the asymptomatic side (measured 10 cm below tibial tuberosity) 1
Pitting edema confined to the symptomatic leg 1
Collateral superficial veins (non-varicose) 1
Previously documented deep vein thrombosis 1
Alternative diagnosis at least as likely as deep vein thrombosis -2
interpreting the Wells score
-2 to 0: low probability,
1 to 2 points: Moderate probability,
3 to 8 points: high probability
in suspected DVT, what else do you look for
pulmonary embolism;
look at pulse, breathing rate, pulse oximetry
investigations for DVT
doppler ultrasound
bloods; d-dimer, FBC, LFTs, clotting screen, urea and creatinine
venous US
treatment
anticoagulation;
IVC filter
anticoagulation therapy?
Heparin whilst waiting for warfarin to increase INR to the target range of 2-3
DVTs that do NOT extend above the knee may be observed and anticoagulated for 3 months
DVTs extending beyond the knee require anticoagulation for 6 months
Recurrent DVTs require long-term warfarin
