Flashcards in VTED Deck (19):
What is meant by Virchow's triad?
Causes of thrombosis:
- Abnormalities in blood flow
- Abnormalities in blood components
- Abnormalities in the vessel wall
What are the signs and symptoms of a PE?
Shortness of breath
Pleuritic chest pain
What investigations should be carried out for a suspected PE?
CXR to rule out other diagnosis
Calculate Wells score
If likely - CTPA
If unlikely - D-dimer, if positive - CTPA
FBC, U&;Es, baseline clotting
What are the key features of a massive a PE?
Hypotension/imminent cardiac arrest
Signs of right heart strain on CT/ECHO, ECG
Consider thrombolysis with IV alteplase
What are the key steps in the management of a PE?
Oxygen if hypoxic
Fluid resus if hypotensive
Thrombolysis if massive PE
Fully anticoagulated - LMWH until INR above 2 or for five days (which ever comes first) then switch to Warfarin - continue for at least 3 months
What are the complications of thrombolysis?
What are the absolute contraindications of thrombolysis?
Haemorrhagic or ischaemic stroke in the past 6months
Recent trauma or surgery
GI bleed in the previous month
Outline the Wells criteria for the scoring of a suspected PE?
Clinical signs and symptoms +3
PE is number 1 Dx +3
HR > 100 +1.5
3 days of immobilisation (bedbound) or surgery with GA in the past month +1.5
Previous VTED +1.5
PE likely if 4.5 or more
What happens in a CTPA?
CT pulmonary angiogram for suspected PE
IV contrast to visualise the pulmonary circulation, it will show up bright white, any mass filling defect will appear dark
What are the contraindications for CTPA?
Decreased kidney function
What happens in a VQ scan?
Assesses the ventilation:perfusion ratio to establish whether the pulmonary circulation has been interrupted
In PE, perfusion is decreased
N.b. Uses high dose radiation
Describe the use of a D-dimer test alongside the Wells scoring system
With a high Wells score, a D-dimer result will make little difference to Mx.
For a moderate to low Wells score, a negative D-dimer will exclude TED, a positive D-dimer needs further imaging
With a low Wells score, PERC rule can also be assessed to exclude PE
What are the major risk factors for VTED?
Previous lower limb orthopaedic surgery
Recent major +/- abdominal surgery
O&G - third trimester, pre-eclampsia
Fracture, varicose veins, reduced mobility
What are the minor risk factors for VTED?
Oestrogen - HRT/COCP
CVS - HF, HTN, CHD
Other- obesity, nephrotic syndrome, IBD
What are the presenting symptoms of a DVT?
What investigations are needed?
Sudden onset localised leg pain
What is the Wells score for DVT?
2+ DVT likely, one point for each of the following
Paralysis, paresis, or recent plaster immobilisation LL
Recently bedridden 3/7 or major GA surgery in past 12/52
Local tenderness along venous system distribution
Entire leg swollen
Calf swelling > 3cm more than unaffected side
Collateral superficial veins
What criteria need to be met to use to Wells score in DVT?
Clinical suspicion of DVT
Asymptomatic for 72hrs before
What further testing should be considered following an unprovoked VTE?
Inherited thrombophilias: factor V Leiden mutation and prothrombin G20210A mutations can be checked at the time of thrombosis
Anti-thrombin 3, protein C and protein S deficiencies should be performed after the event. They are depressed at the time of acute thrombosis and by Heparin and Warfarin