Thrombotic Disorders Flashcards
Deep veins in leg
Iliac, femoral, popliteal, tibial
Superficial leg veins
Greater saphenous, lessor saphenous
DVT
deep vein thrombosis
Thrombotic risk factors
Post-op (orthopaedic) Hospitalisation Pregnancy OCP Long haul flights Cancer Obesity Drug abuse
Presentation of DVTs
Unilateral calf swelling/ heat/ pain/ redness/ hardness
Cellulitis
Baker’s cyst
Muscular pain
Doppler ultrasound
ultrasound transducer produces a real time 2D image of soft tissue structure
Colour duplex shows velocity and direction of blood flow
Veins are non-compressible by U/S probe
Birchow’s triad of thrombosis
Circulatory stasis, hypercoagulable state, endothelial injury
D dimer test
Likelihood of having a DVT can be assessed
Indicate activation of clotting cascade
Low wells score and negative d-dimer test have high negative predictive values
Initial DVT treatment
Therapeutic anti-coagulation using sub-cat LMW (low molecular weight) heparin
Dosing done according to patients weight
If someone has renal impairment then anti-coagulate with IV unfractionated heparin
Subsequent DVT treatment
Load patient with oral warfarin for 3-5 days
Stop LMW heparin once INR is over 2 for 2 days
1st femoral/ iliac DVT
Secondary treatment: 6 months warfarin
2nd DVT/PE
Treatment: lifelong warfarin
Target INR
Between 2-3 (2.5)
PE symptoms
Pleuritic pain
Dyspnoea
Haemoptysis
PE on examination
tachycardia, tachypnoea, hypotensive
Massive PE
Sycope, death
CPTA
CT pulmonary angiogram
Saddle embolism
Large pulmonary thrombo-embolism that straddles the main pulmonary arterial trunk at its bifurcation
V/Q scans
Radio isotope shows under-perfusion (V/Q mismatch) due to PE
Indeterminate scans - can’t tell what the underlying cause is so rarely done
ECG
Shows sinus tachycardia, atrial fibrillation, right heart strain
Chest X-ray
Usually normal, shows linear atelectasis, small effusions
PE outcomes
5% mortality with treatment 4% develop pulmonary hypertension
Leading cause of preventable death
Treatment of massive PE
Thrombolysis and IV heparin
2-6% risk of serious bleeding
Treatment of standard PE
LMW heparin injections (Tinzaparin)
Warfirin for 6 months
Inferior VC filters
Consider DOAC (NOACs) as alternatives
LMW heparin better if
There is an underlying cancer
Thrombophilia screen
Done in younger patients
Can be inherited:
Factor 5 leiden, prothrombin gene variant, anti-thrombin deficiency, protein C and S deficiency
Can be acquired from anti-phospholipid syndrome
