Thromboprophylaxis for Orthopaedics and Trauma Admissions

Assessment of VTE and bleeding risk

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.

Different specialty specific algorithms apply for medical, surgical and obstetrics (refer to AthenA).

Further information on assessment:

  • For every patient, consider mechanical prophylaxis.
  • Do not offer pharmacological prophylaxis to patients with risk factors for bleeding shown in table 2 below.
  • Patients already receiving therapeutic anticoagulation do not need additional thromboprophylaxis.

Table 1 – Indicators of patients at increased risk of VTE

Regard patient as being at increased risk of VTE if they have one or more of the following risk factors:

  • Age >60 years
  • Dehydration
  • Obesity (BMI >30kg/m2)
  • Any significant medical illness (e.g. heart, metabolic, endocrine, or respiratory disease; acute infection; inflammatory condition)
  • Use of hormone replacement therapy
  • Use of oestrogen-containing contraceptive
  • Active cancer or cancer treatment
  • Known thrombophilias
  • Pregnancy or <6 weeks post partum
  • Varicose veins with phlebitis
  • Personal history or 1st degree relative with a history of VTE
  • Significantly reduced mobility for 3 days or more
  • Surgery with significant reduction in mobility
  • Critical care admission (e.g. HDU, ITU)
  • Hip or knee replacement
  • Hip fracture
  • Total anaesthetic + surgical time >90 minutes
  • Surgery involving pelvis or lower limb with a total anaesthetic + surgical time >60 minutes
  • Acute surgical admission with inflammatory or intra-abdominal condition
  • Achilles tendon rupture
  • Ankle fracture with splint/cast + non-weight bearing
  • Lower limb injury with splint/cast + non-weight bearing

N.B. Consider any admissions or illnesses since pre-operative assessment.

Table 2 – Indicators of patients at high risk of bleeding and contraindication to pharmacological VTE prophylaxis

Regard patient at risk of bleeding, and a contraindication to pharmacological VTE prophylaxis, if they have any of the following risk factors:

  • Active bleeding
  • Recent stroke
  • Acute gastro-duodenal ulcer
  • Acute bacterial endocarditis (discuss with cardiologist)
  • Known hypersensitivity (including heparin induced thrombocytopenia, HIT)
  • Thrombocytopenia (platelet count <75 x 109/L)
  • Concurrent use of therapeutic heparin
  • Concurrent use of oral anticoagulants 
  • Concurrent use of oral dual anti-platelets - see below for further guidance
  • Untreated inherited bleeding disorders (e.g. haemophilia, von Willebrand's disease)
  • Acquired bleeding disorders, e.g. acute liver failure
  • Uncontrolled hypertension (BP ≥230/120mmHg)
  • Epidural / spinal anaesthesia or lumbar puncture in previous 4 hours or expected within next 12 hours
  • Any other procedure with high bleeding risk
  • Neurosurgery, spinal or eye surgery

N.B. Patients with an Acute Coronary Syndrome or suspected DVT/PE should receive fondaparinux or treatment dose dalteparin as appropriate following local clinical guidelines.

General management and treatment options

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.

Prophylactic dalteparin dosing adjustments

Dalteparin dose is dependent on weight and renal function. Refer to guidance on dalteparin dose adjustment below in patients with:

  • weight <50kg or ≥100kg
  • creatinine clearance (CrCl) <30ml/minute.

Table 3 - Dalteparin dose adjustment

 

Body weight

 Dalteparin subcutaneous dose
CrCl ≥30ml/min CrCl <30ml/min (renal adjusted dose)
<50kg 2500 units once daily* 2500 units once daily*
≥50kg  to  <100kg

5000 units once daily

 

5000 units once daily
≥100kg  to  ≤150kg

5000 units twice daily*
>150kg

7500 units twice daily*

Seek haematology advice

*Off-label dosing.

No routine monitoring (i.e. anti-Xa levels) is required. Refer to haematology if cause for concern.

Patients on long term anti-platelets prior to surgery

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 anticoagulants prior to surgery

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.

Precautions with epidural / spinal anaesthesia and lumbar puncture

Do not give LMWH if epidural / spinal anaesthesia or lumbar puncture in previous 4 hours or expected within 12 hours.

Mechanical prophylaxis

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

General recommendations

  • Facilitate early mobilisation as soon as possible.
  • Ensure adequate hydration.
  • Reassess VTE risk and bleeding risk regularly, review treatment plan where appropriate and document any changes in notes.
  • Do not offer VTE prophylaxis to patients on full anticoagulant therapy.
  • Pre-existing established anti-platelet therapy:
    • Assess risks and benefits of stopping
    • Do not regard anti-platelet therapy as adequate VTE thromboprophylaxis.

 

Guideline reviewed February 2023
Page updated April 2025



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