All patients must have their risk of venous thromboembolism (VTE) assessed at admission (+/- at pre-admission clinic) using the orthopaedics and trauma VTE prophylaxis risk assessment proforma and then every 48 hours.
Further information on assessment:
Regard patient as being at increased risk of VTE if they have one or more of the following risk factors:
Regard patient at risk of bleeding, and a contraindication to pharmacological VTE prophylaxis, if they have any of the following risk factors:
N.B. Patients with an Acute Coronary Syndrome or suspected DVT/PE should receive fondaparinux or dalteparin as appropriate following local clinical guidelines.
Emergency Admission/Trauma |
Pelvic Fracture - Dalteparin SC 5000units† once daily for 28 days. Hip Fracture - Dalteparin SC 5000units† once daily for 35 days. Spinal Injury Patients are treated as per Local Spinal Injuries Policy. |
Elective Total Hip Replacement |
First line: Dalteparin SC 5000units* once daily for 35 days. Second Line: Dalteparin SC 5000units* once daily for 10 days and then Aspirin oral 150mg once daily for a further 28 days. |
Elective Total Knee Replacement |
First Line: Dalteparin SC 5000units* once daily for 14 days. Second line: Aspirin oral 150mg once daily for 14 days. |
Other Elective/Trauma Admissions Consider additional predisposing risk factors – see risk assessment tool |
Dalteparin SC 5000units* once daily until discharge/mobile. Extended prophylaxis should be considered for patients with additional predisposing risk factors. |
Outpatients and Day Surgery patients treated for lower limb injuries that require them to be non-weight bearing |
First Line: Rivaroxaban oral 10mg once daily (off-label) for period of immobility (maximum 35 days). N.B. if eGFR 15-29ml/min – use with caution; if eGFR <15ml/min – avoid. Second Line: Dalteparin SC 5000units* once daily for period of immobility (maximum 35 days). |
†Commenced 6-12 hours post-operatively (withhold 12 hours prior to surgery). *Commenced 6-8 hours post-operatively. N.B. See dalteparin dosing adjustments for extremes of weight and renal impairment below. |
See table 3 for dalteparin dosing guidance according to body weight in normal renal function.
Normal renal function | ||||
<50kg | 50-100kg | 100-150kg | >150kg | |
Dalteparin SC |
2500units once daily (off-label) |
5000units once daily |
5000units twice daily (off-label) |
7500units twice daily (off-label) |
For patients with eGFR <30ml/min, see table 4 for dalteparin dosing guidance according to body weight in renal impairment.
eGFR <30ml/min | ||||
<50kg | 50-100kg | 100-150kg* | >150kg* | |
Dalteparin SC |
2500units once daily (off-label) |
5000units once daily |
5000units once daily (off-label) |
Seek haematology advice |
*N.B. In patients with eGFR <30ml/min and bodyweight >100kg subsequent assessment of anti-Xa levels are advised.
Patients on any antiplatelet medication, including aspirin, clopidogrel, ticagrelor or prasugrel have an increased risk of bleeding.
However, it is considered that thromboprophylaxis with low molecular weight heparin (LMWH) post orthopaedic surgery in a patient on a single long term antiplatelet agent is acceptable in most cases.
If a patient is on dual antiplatelet therapy (DAPT), the risk of thrombus vs risk of bleeding must be discussed with the specialist who recommended the antiplatelet treatment. This discussion should take place at pre-assessment where possible or as early as possible following surgery. A treatment plan must be recorded in the patient’s notes.
Patients on oral anticoagulant therapy, including warfarin, phenindione, rivaroxaban, apixaban, edoxaban or dabigatran, should have these stopped prior to any elective procedure and may require bridging. This should be decided at pre-operative assessment and should be documented in the patient’s notes. Oral anticoagulants can usually be restarted as soon as clinically appropriate post procedure.
Patients on warfarin may require LMWH in combination with warfarin until therapeutic INR has been achieved. See Perioperative Anticoagulant Guideline (link only active if accessing via NHS network) for additional information, including the management of non-elective patients.
Do not give LMWH if epidural / spinal anaesthesia or lumbar puncture in previous 4 hours or expected within 12 hours.
Consider mechanical prophylaxis for all patients particularly if they have contraindications to LMWH, or if LMWH not required and early mobilisation is possible.
Apply on admission and continue until there is a return to the pre-morbid level of mobility. Note, Intermittent Pneumatic Compression (IPC) devices (Flowtron®) or foot impulse devices should be applied peri-operatively.
Advice on how to apply correctly and duration of wear should be given to the patient.
Contraindications to mechanical prophylaxis | |
Pulmonary oedema | Pressure sore |
Peripheral arterial/vascular disease | Peripheral neuropathy |
Cellulitis | Local leg conditions, e.g. dermatitis |
Leg oedema | Extreme deformity |
Leg / foot ulceration | Acute stroke |
Guideline reviewed | February 2023 |
Page updated | May 2023 |