VTE Prophylaxis for Patients Undergoing Colorectal Surgery - Reducing the risk of venous thromboembolism

Publication: 05/12/2016  
Next review: 11/08/2024  
Clinical Guideline
ID: 4827 
Approved By: Trust Clinical Guidelines Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2021  


This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Thromboprophylaxis Guidelines for Surgical Patients


Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients admitted to hospital for patients undergoing colorectal surgery.

Back to top


NICE guideline 89; Venous thromboembolism in over 16s: reducing the risk of hospital-acquired deep vein thrombosis or pulmonary embolism was published in March 2018.  Leeds Teaching Hospitals are adding to Leeds Health Pathways local guidance for VTE risk assessment and management based on NICE guidance.

Back to top

Risk Assessment

Leeds Teaching Hospitals risk assessment tool is used to stratify the risk of VTE for each patient.

Back to top

Treatment / Management

1.1 General Information
All patients are risk assessed and identified for risk of VTE and risk of bleeding. This should comprise of: -

  • Individual Patient risk factors (see VTE assessment form)
  • Bleeding Risks / contraindications (see VTE assessment form)
  • Procedure Risk Factors (see attached table for surgical specialty)

The most appropriate thromboprophylaxis is then prescribed.

Treatment Pathway: Thromboprophylaxis in the Surgical Patient


All patients should be risk assessed for VTE and bleeding risk on admission or by the time of first consultant review. This should be repeated at consultant review and whenever the clinical situation changes.
If a patient requires thromboprophylaxis enoxaparin is the low molecular weight heparin (LMWH) of choice and should be started within 14 hours of admission.

For Women who are pregnant or have given birth within 6 weeks see separate guidance / seek advice.

1.2 Day surgery / Same day of surgery (SDOS) admission
See separate guidance for patients being admitted for SDOS (http://nww.lhp.leedsth.nhs.uk/common/guidelines/detail.aspx?id=2569).

1.3 Definition of Reduced Mobility
Significantly reduced mobility is defined as patients who are bedbound, unable to walk unaided or likely to spend a substantial proportion of the day in bed or in a chair.

1.4 Patients undergoing Spinal/regional analgesia
For patients who will be receiving a lumbar puncture/epidural/spinal anaesthesia see “Clinical Practice Guidelines for the Delivery of Epidural and Paravertebral Analgesia in Adult Acute Pain Management”: -

  • Do not give low molecular weight heparin (LMWH) within 12 hours prior to starting an epidural / spinal anaesthesia
  • Do not restart LMWH till 4 hours after epidural / spinal anaesthesia removed

1.5 Risk Factors for Bleeding

  • Active bleeding
  • Acquired bleeding disorders e.g. acute liver failure
  • Untreated inherited bleeding disorders e.g. haemophilia
  • Concurrent use of anticoagulants e.g. warfarin warfarin with INR >2 or  apixaban, dabigatran, edoxaban, rivaroxaban or INR greater than 2
  • Acute stroke
  • Thrombocytopenia (platelets less than 75x109/l
  • Uncontrolled systolic hypertension (230/120 mmHg)

1.6 Extended Prophylaxis

  1. Add VTE prophylaxis for a minimum of 7 days for people undergoing abdominal surgery whose risk of VTE outweighs their risk of bleeding, taking into account individual patient factors and according to clinical judgement
  2. Extend VTE prophylaxis to 28 days postoperatively for patients who have had *major cancer surgery in the abdomen or pelvis
  3. Extended VTE prophylaxis for 28 days should be considered postoperatively for patients who have undergone *major colorectal surgery who also meet one or more of the following criteria:
    1. The patient has undergone a surgical procedure with a total anaesthetic/surgical time of more than 90 minutes
    2. An open surgical procedure was used
    3. The patient has had an acute surgical admission with an inflammatory or intra-abdominal condition
    4. The patient is expected to have a significant reduction in mobility
    5. The patient has undergone a procedure which caused compression of the femoral arteries due to positioning -  Extended VTE for these patients should be specifically stated by surgeon on the op-note

*major colorectal surgery accounts for the following:
Anterior resection, Abdominoperineal resection of rectum (APER), Hartmann’s procedure, ileoanal pouch surgery, panproctocolectomy, pelvic exenteration, all forms of colectomy/ileostomy, bowel resections (acute or elective) and laparotomies for restoration of GI continuity eg ileocolic reanastamosis.

For all OTHER colorectal surgical procedures, the need for 28 days extended VTE prophylaxis should be clearly stated on the patient’s post-op note in order for patients to receive this on discharge.

Continue extended thromboprophylaxis at a weight-adjusted dose where patients are <50 or >100kg

1.7 VTE Risk Factors -
Patient risk factors see Risk assessment form

  • Active Cancer treatment
  • Age over 60 years
  • Critical Care admission
  • Dehydration
  • Known thrombophilias
  • Obesity (BMI over 30kg/m2)
  • One or more significant medical comorbidities e.g. heart disease, metabolic, endocrine or respiratory pathologies, acute infectious disease or inflammatory conditions)
  • History of VTE
  • Use of hormone replacement therapy
  • Use of oestrogen containing contraceptive therapy
  • Varicose veins with phlebitis

Surgical risk factors see surgical procedure table

  • Surgical procedure longer than 90 minutes, or 60 minutes for pelvis/lower limb surgery
  • Acute surgical admission with inflammatory or intra-abdominal condition
  • Expected significant reduction in mobility (see section 1.3 of guideline)

Consideration should be given to cease hormone replacement therapy or oestrogen containing contraceptives for 4weeks prior to surgery, where possible, to reduce VTE risk.

1.8 Patients on Oral Anticoagulants
The guidance regarding bridging therapy for patients taking oral anticoagulants undergoing elective surgical procedures should be followed. (http://nww.lhp.leedsth.nhs.uk/common/guidelines/detail.aspx?ID=3084)

1.9 Enoxaparin Dosing for patients with creatinine clearance (CrCl) over 30mL/min


Dose of Enoxaparin


20mg daily

50 - 100kg

40mg daily

101 - 150kg

40mg twice daily


60mg twice daily

1.10 Enoxaparin Dosing for patients with creatinine clearance (CrCl) less than 30mL/min


Dose of Enoxaparin


20mg daily with caution - consider Factor Xa levels

50 - 100kg

20mg OD daily

101 - 150kg

40mg OD daily


60mg OD daily

1.11 All heparins are porcine based
If patients do not want a porcine based product consider fondaparinux 2.5mg s/c once a day reduced to 1.5mg s/c once a day if CrCl 20 - 50ml/min. Contra-indicated if CrCl < 20ml/min.

1.12 Information for Discharge
Notify the patient’s GP if they have been discharged with pharmacological and/or mechanical VTE prophylaxis to be used at home.

1.13 Patient Information
All patients should be given verbal and written information about their risk of VTE on admission. This should include what will happen, side effects and how they can help to reduce the risk. On discharge they should be given verbal and written information about the signs and symptoms of VTE and what to do should they occur. They should also be given instructions on how to use their thromboprophylaxis if required on discharge and how long it should continue for. Leaflet LN004075 contains this information and is available to order from the print unit.

Monitoring for Heparin Induced Thrombocytopenia (HIT)
All patients started on any type of heparin should have a baseline platelet count performed.
For patients who have received heparin of any form in the previous 100 days a platelet count at 24 hours is advised.
Further monitoring is not required for patients on low molecular weight heparin (LMWH).
If HIT is suspected please refer to the Guideline on Diagnosis and Management of HIT
This is based on national guidance from the British Committee for Standards in Haematology November 2012.


Record: 4827
Objective: To provide evidence-based recommendations for appropriate venous thromboembolism (VTE) risk assessment and management of patients admitted to hospital
Clinical condition: VTE thromboprophylaxis in surgical patients
Target patient group: Colorectal Surgery patients
Target professional group(s): Pharmacists
Secondary Care Doctors
Secondary Care Nurses
Adapted from:

Evidence base

  1. Venous thromboembolism in over 16s: reducing the risk of hospital-acquired deep vein thrombosis or pulmonary embolism.  NICE guideline [NG89]. Accessed October 2019. https://www.nice.org.uk/guidance/ng89
  2. Clinical Practice Guidelines for the Delivery of Epidural and Paravertebral Analgesia in Adult Acute Pain Management - Leeds Teaching Hospitals NHS Trust , Last review: December 2013, accessed March 2016 http://nww.lhp.leedsth.nhs.uk/common/guidelines/detail.aspx?ID=187
  3. Guidelines For The Perioperative Management Of Oral Anticoagulation In Patients Undergoing Elective Procedures - Leeds Teaching Hospitals NHS Trust, published September 2012, accessed March 2016.
  4. LMWH prescribing at extremes of body weight - Leeds Teaching Hospitals NHS Trust, published July 2015, accessed March 2016     

Approved By

Trust Clinical Guidelines Group

Document history

LHP version 2.0

Related information

Not supplied

Equity and Diversity

The Leeds Teaching Hospitals NHS Trust is committed to ensuring that the way that we provide services and the way we recruit and treat staff reflects individual needs, promotes equality and does not discriminate unfairly against any particular individual or group.