Venous Thrombosis - Diagnosis, Prevention and Treatment of PE/DVT Flashcards
Why is DVT diagnosis difficult
Symptoms are non-specific
Symptoms of DVT
Pain, swelling
Signs of DVT
Tenderness
Swelling
Warmth
Discolouration
How does D-dimer levels help in DVT investigation
Normal = Exclude diagnosis
Positive = Potential but not confirmation
Following a D-dimer test what do we carry out for patients with suspected DVT
Ultrasound compression test on proximal vein or venogram for calf
How is DVT treated
LMW Heparin for min 5 dyas
Oral Warfarin (5mg a day), INR 2-3 for 6 months
Compression Stockings
Treat underlying cause (malignancy or thrombophilia)
Is DVT more spontaneous or provoked after first case
Spontaneous
What are the risk factors for DVT
- Surgery, Immobility, leg fracture
- OC pill, HRT, Pregnancy
- Long flights and travel
- Inherited thrombophilia (familial inheritance)
How can we mechanically prevent DVT
Hydration, early mobilisation
Compression stockings
Foot Pumps
Chemical prevention of DVT
LMW Heparin
What is the risk of thromboprophylaxis at <40 years
Low
How do we treat low risk thromboprophylaxis
Early mobilisation, hydration (no chemical intervention) and a 30 min surgery
What factors can result in high risk thromboprophylaxis
Hip and knee surgery
Pelvis surgery
Malignancy
Prolonged Immobility
How is high risk thromboprophylaxis treated
Many surgeries
Daltrparin
What are the main components of a venous thrombi
RBC
Fibrin
Where does DVT begin
Vein valves
What are D-dimers
Fibrin degradation product that can increase when plasmin is dissolving a clot
Mechanism of action of heparin
- Binds to antithrombin III
2. Antithrombin inactivates thrombin, factor Xa
Difference between unfractioned heparin and LMW Heparin
- Binds to antithrombin
2. Binds to antifactor Xa instead
What is the advantage of LMWH and Fondaparinux to Unfratcioned heparin
Reduces the risk of heparin-induced thrombocytopenia
Why is a common consequence of DVT pulmonary embolism
The clot can detach and move into the heart, pushed into the lungs where it can lodge
How can DVT-caused pulmonary embolisms effect the body
- Hypotension
- Cyanosis
- Severe dyspnoea
- Right heart failure
How do we treat DVT with pulmonary embolism
Embolectomy or tPA (Thrombolysis)
Common presentation of DVT-caused pulmonary embolisms
- Chest Pain
- Sob
Could be mistaken for malignancy, infection, cardiac or gastric causes - NOTE
Symptoms of pulmonary embolisms
- Breathlessness
- Pleuritic chest pains
- Risk factors
Signs of pulmonary embolisms
- Tachycardia
2. Pleural rub
Initial Investigations for PE
- CXR - Normal
2. ECG sinus tacky (QI, SI, TIII)
What should blood gases in initial PE investigation look like
1, Type I rest failure and decreased O2 and Co2 levels
Further investigations after initial check up of PE
- D-dimer (should be normal = exclude diagnosis)
- Ventilation/Perfusion sac (mismatch defects)
- CTPA spiral CT with contrast to visualise major segmental thrombi
How is PE treated
NOTE: ENSURE NORMAL Hb, platelets, renal function and baseline clotting
LMW heparin of weight adjusted 5/7
Oral Warfarin INR 2-3 for 6 months
DOAC
Treat cause
IF a person with PE can’t anti-coagulate what do we give them
IVC filter
How is PE prevented
- Early mobilisation and hydration
- Mechanical
- LMW Heparin
Name two DOACs
Rivaroxaban
Apixaban