Deep Vein thrombosis Flashcards
What is a DVT?
A deep vein thrombosis (DVT) refers to the formation of a thrombus within the deep venous system, most often occurring in the veins of the leg but also in the pelvis and arm.
What can happen if the thrombus becomes dislodged?
If this thrombus becomes dislodged, it becomes an embolus and can travel to the lungs causing a pulmonary embolism (PE)
What are DVT and PEs examples of?
Venous thromboembolism
What % of surgical patients are affected by DVTs?
25-50%
Give the 3 broad factors of thrombosis risk according to Virchow’s triad:
1) stasis
2) vessel wall injury
3) hypercoagulability
Give 5 instances where the blood may become more coagulable?
1) pregnancy
2) nephrotic syndrome
3) cancer
4) smoking
5) post-burn
What can increase likelihood of stasis?
- Immobility
- Varicose veins
- Obesity
What can cause endothelial injury?
- Physical trauma
- Foreign devices
- Hypertension
- Bacterial infection
Give 8 patient risk factors for DVTs:
1) obesity
2) previous DVT/PE
3) increasing age
4) immobility/ bed rest for 4> days
5) continuous travel for >3 hours in proceeding 4 weeks
6) contraceptive pill
7) varicose veins
8) pregnancy
Give 8 diseases/ procedures that increase the risk of DVTs:
1) cancer
2) nephrotic syndrome
3) IBD
4) sickle cell anaemia
5) recent MI or stroke
6) cardiac/ respiratory failure
7) central venous catheter
8) trauma/ surgery to lower limbs
Give 5 potential presentations of deep vein thrombosis:
1) leg pain
2) swelling, redness and warmth of leg
3) cyanotic discolouration if complete occlusion
4) mild fever
5) ulceration in chronic instances
What % of DVTs are asymptomatic?
65%
Give 3 DVT-associated examination findings:
1) pitting oedema
2) distention/ bulging of superficial veins
3) Homan’s sign (calf pain on sudden, passive dorsiflexion during knee extension - not very specific)
Give 3 potential differential diagnoses for a red, painful, swollen leg:
1) cellulitis
2) venous eczema
3) ruptured Baker’s cyst
What is a Baker’s cyst?
a popliteal cyst seen in pseudo-thrombophlebitis
What is a pseudo-thrombophlebitis?
signs and symptoms of venous inflammation in the absence of a thrombophlebitis region
What score system is used to estimate the risk of DVT?
Well’s score
What score on the Well’s Score indicates ‘likely’ chance of a future DVT?
2 or more points
What lab investigation should be carried out first when suspecting a DVT?
Quantitative D-Dimer Level
How does a D-Dimer blood test help diagnose DVT?
D-Dimer is a degradation product of fibrin which is formed by blood clots
What investigation should be carried out if a D-Dimer test comes back positive to finalise a diagnosis of DVT?
Proximal Duplex Ultrasound
Give two ultrasound signs that indicate DVT:
1) inability to compress the lumen of the vein using the ultrasound transducer
2) reduced flow in vein
Give the two main categories of DVT management:
- Anticoagulation
- Procedures
What is the name of the minor surgery that uses a catheter to deliver anticoagulants to the thrombus?
catheter directed thrombolytic therapy
