Table of Contents
VTE risk factors
- Age >60
- BMI >30
- Dehydration
- Immobility ≥3 days
- Active cancer
- Significant comorbidities
- HRT/oestrogen contraceptives
- Phlebitis/varicose veins
- Surgery taking >90 minutes (or >60 minutes on lower limb/pelvis)
- Pregnancy/<6 weeks post-partum
- Inflammatory condition
- Thrombophilia or PMHx / FHx of VTE
- Obesity
- Critical care admission
Pharmacological prophylaxis
LMWH/fondaparinux or unfractionated heparin are the most commonly used medications for pharmacological VTE prophylaxis.
- Pharmacological prophylaxis is used for most patients (unless contraindicated)
- Assess for contraindications/cautions:
- Not required
- Patient taking therapeutic anticoagulant (INR>2 if on warfarin)
- Procedures
- Invasive procedure scheduled within next 12 hours
- Invasive procedure performed within previous 4 hours
- Significant bleeding risk
- Active bleeding/stroke
- Thrombocytopenia (platelets <75×109/L)
- Bleeding disorders
- Acute stroke
- SBP >230mmHg
- Not required
- Weigh up the risks and benefits of anticoagulation (discuss with senior if unclear)
- If the benefits outweigh the risks, determine renal function and weight. Each hospital will have a recommended protocol. Example for patients 50-100kg:
- eGFR >30 – prophylactic-dose LMWH/fondaparinux (e.g. enoxaparin 40mg S/C OD)
- eGFR <30 – prophylactic-dose unfractionated heparin (e.g. heparin 5000 units S/C BD)
Mechanical prophylaxis
Thromboembolic deterrent stockings (TEDs) or foot impulse devices/intermittent pneumatic compression devices (IPCs) may be used for mechanical VTE prophylaxis.
- Mechanical prophylaxis is used for patients unable to take pharmacological prophylaxis, and in addition to pharmacological prophylaxis in surgical patients
- Choice depends on individual patient factors and condition/intervention
- Assess for contraindications:
- Peripheral arterial disease
- Fragile skin, e.g. ‘tissue paper skin’, dermatitis, or recent skin graft
- Severe peripheral oedema
- Cardiac failure
- Leg deformity
- Peripheral neuropathy
To complete
- ‘I have ensured there are no contraindications, weighed up the risks and benefits, and determined renal function and weight. After obtaining patient consent, I would like to prescribe:
- LMWH/fondaparinux as per hospital protocol (e.g. enoxaparin 40mg subcutaneously) once every evening
- And/or thromboembolic deterrent stockings or foot impulse devices/intermittent pneumatic compression devices.’
- ‘I would reassess the patient’s anticoagulation needs 24 hours after admission.’