Deep vein thrombosis Flashcards
Risk factors
Strong medical hospitalisation within the past 2 months major surgery within 3 months active cancer lower-extremity trauma increasing age pregnancy obesity factor V Leiden prothrombin gene mutation G20210A protein C or S deficiency antithrombin deficiency antiphospholipid antibody syndrome medical comorbidity recent long-distance air travel use of specific drugs->OCP nephrotic syndrome
family hx
Signs
Calf warmth, swelling, tender
Mild fever
Pitting edema
Homan’s sign->should not be tested as can dislodge a clot
History- important
Symptoms
Recent surgery, presence of an active cancer, lower-extremity trauma, recent hospitalisation, recent immobility, and presence of underlying chronic medical illness. Family history of venous thrombosis or PE
current pregnancy, obesity, factor V Leiden mutation, prothrombin gene mutation G20210A, protein C or S deficiency, antithrombin (AT) deficiency, antiphospholipid antibody syndrome, acute medical comorbidity (especially those associated with inflammation, infection, and immobility), recent long-distance air travel, and use of certain drugs including oestrogen- or third-generation progestogen-containing oral contraceptives, tamoxifen, raloxifen, thalidomide, or erythropoietin
Physical examination
Wells score assessment
Wells score
Wells’ criteria:
Active cancer (any treatment within past 6 months): 1 point
Calf swelling where affected calf circumference measures >3 cm more than the other calf (measured 10 cm below tibial tuberosity): 1 point
Prominent superficial veins (non-varicose): 1 point
Pitting oedema (confined to symptomatic leg): 1 point
Swelling of entire leg: 1 point
Localised pain along distribution of deep venous system: 1 point
Paralysis, paresis, or recent cast immobilisation of lower extremities: 1 point
Recent bed rest for >3 days or major surgery requiring regional or general anaesthetic within past 12 weeks: 1 point
Previous history of DVT or PE: 1 point
Alternative diagnosis at least as probable: subtract 2 points.
Interpreting wells
> 2 points->diagnosis likely
Occurence of DVT
1 in 1000 live adults
Percentage of people who experience post-thrombotic syndrome after DVT
60%
Investigations
Well's D-dimer Venous duplex USS INT/aPTT UEC LFTs FBC
CT abdomen pelvis if filling defect
Thrombophilia screen->no predisposing, recurrent, family history
Tests in thrombophilia screen
Anti-cardiolipin Lupus anticoagulant Beta-2 glycoprotein Protein C and S Factor V leiden Prothrombin Antithrombin
Management
Graduated compression stocking
Mobilisation
Enoxaparin
Warfarin
Duration of warfarin
Clinical situation Duration VTE provoked by a transient major risk factor 3 months unprovoked distal DVT 3 months first unprovoked proximal DVT or PE 6 months first unprovoked VTE plus: active cancer multiple thrombophilias antiphospholipid antibody syndrome indefinite recurrent unprovoked VTE indefinite
When would you consider IVC filter
When active bleeding
Anticoagulants fail
Overview of approach to DVT prophylaxis
Reduce risks Early mobilisation Fluids Pharmacotherapy Mechanical Analgesia Physiotherapy
Considerations for DVT prophylaxis
- Surgery required
- Other medical conditions which can +risk
- Contraindications
- Mechanical
Surgical risk stratification general
- Any surgical procedure
- especially abdominal, pelvic, thoracic or orthopaedic surgery.
- Major joint surgery and curative surgery for cancer carry very high VTE risk
- leg injury requiring surgery or prolonged immobilisation
- prolonged surgery and/or prolonged immobilisation.
Medical conditions that can +risk
Chronic medical conditions Paresis \+Age (low risk) OCP/HRT Varicose veins (low risk) Previous VTE Thrombophilia Malignancy Trauma/surgery Indwelling catheter DM Pregnancy/Peripartum Extended travel Myeloproliferative disease CCF, COPD IBD, Obesity (low risk)
Contraindications to prophylaxis
Inherited/acquired bleeding disorder,
coagulopathy, DIC–>
Need INR, PTT
PLT disorders
Differential diagnosis
Cellulitis Calf muscle tear Calf muscle hematoma Baker's cyst Pelvic/thigh mass/tumour compressing venous outflow from the leg Thrombophlebitis Compartment syndrome
Differentiating features in cellulitis
- Patients with cellulitis usually manifest redness, heat, and swelling in the dermis of the affected leg. The affected area is likely to be smaller than in DVT (which may involve the entire foot, calf, or thigh), but the signs more pronounced.
- The demarcation of the skin margins more defined
- Portal of infection entry may be identified. [71]
- Fever and prior history of cellulitis is common.
May occur with a concurrent DVT
Differentiating thrombophlebitis
Superficial inflammation of the veins with secondary thrombosis; manifests with a firm and tender varicose vein, low-grade fever, and oedema of the extremity
