Thrombo-embolism Flashcards
What are the symptoms of PE?
SOB Pleuritic, sharp chest pain Tachypnoea Tachycardia Haemoptysis Signs of DVT
What are the signs of a DVT?
Pitting oedema Warmth Tenderness along deep veins distribution Erythema Dilated superficial veins
If you suspect a PE, what investigations should you do?
D-dimer, USS doppler if there is a likely DVT too
CTPA if you do suspect a PE
Or V/Q scan if renal impairment or contrast allergy
CXR: more to rule out anything else
ECG: sinus tachy
ABG
Bloods
Comment on the D dimer test’s sensitivity and specificity?
Poor specificity but good sensitivity
A negative result practically rules out a DVT. A positive result does not definitely mean there’s a DVT, because other things can caused a raised D dimer
Sensitivity and specificity. If high, which rules in and which rules out?
SNOUT: sensitivity rule things out
SPIN: specificity rules things in
List some risk factors for a VTE?
Previous VTE Active cancer Pregnancy or puerperium Reduced mobility IVDU Immobilisation CVS history Obesity Female Smoking and alcohol Oestrogen (COCP, HRT)
What’s the scoring system used to assess likelihood of it being a DVT?
What is in it?
Well’s score
Active cancer
Calf swelling >3cm compared to other calf
Collateral superficial veins
Pitting oedema
Swelling of entire leg
Localised tenderness along deep venous system distribution
Paralysis, paresis, immobilisation of lower extremities
Recently bedridden or major surgery in last 12 weeks
Previous DVT
Alternative diagnosis is likely (lose 2 points
What ECG changes might you see in a PE?
Sinus tachycardia
S1 Q3 T3
- prominent S wave in lead I
- prominent Q wave in lead III
- T wave inversion in lead III
What investigations should you do for a DVT?
D dimer
If D dimer raised and Well’s score indicates moderate-high risk then do a USS doppler
How can you prevent a DVT in hospital patients?
Early mobilisation
LMWH daily
Compression (TED) stockings
Intermittent pneumatic compression devices
Treatment of DVT?
LMWH and warfarin or DOAC
Start at the same time. Warfarin is prothrombitic in the first 48 hours so you need the LMWH.
You can stop the LMWH after 5 days or once INR is 2-3
Continue warfarin for:
- 3 months if post-op
- 6 months if no apparent cause
- lifelong if recurrent DVTs or thrombophilia
IVC filters are good for patients who’re actively bleeding or when anti-coagulants don’t work.
When would an IVC filter be indicated as treatment for DVT?
If patient is actively bleeding
If recurrent DVTs despite anti-coagulant therapy
How does a Well’s score of 1 or less dictate further investigations?
DVT unlikely
Do D-dimer
- If DD negative rule out DVT
- If DD positive do an USS
USS:
- If USS negative rule out DVT
- If USS positive treat as DVT
How does a Well’s score of 2 or more dictate further investigations?
Do a D-dimer and USS
- If both negative rue out DVT
- If USS positive only, treat as DVT
- If D-dimer positive only, repeat USS in 1 week
What is thrombophilia?
Causes?
Blood has increased tendency clot, increasing chance of VTE
Genetic causes: factor V leiden, prothrombin 20210
Auto-immune: anti-phospholipid syndrome
