Intended for healthcare professionals

Practice Guidelines

Reducing the risk of venous thromboembolism in patients admitted to hospital: summary of NICE guidance

BMJ 2010; 340 doi: (Published 27 January 2010) Cite this as: BMJ 2010;340:c95
  1. Jennifer Hill, guidelines operations director1,
  2. Tom Treasure, chair of the guideline development group2
  3. On behalf of the National Clinical Guideline Centre for Acute and Chronic Conditions
  1. 1National Clinical Guideline Centre for Acute and Chronic Conditions, Royal College of Physicians, London NW1 4LE
  2. 2Clinical Operational Research Unit, University College London, London WC1H 0BT
  1. T Treasure tom.treasure{at}

    Why read this summary?

    Of an estimated 25 000 deaths in England each year attributable to hospital acquired venous thromboemobolism (VTE), many are potentially preventable.1 2 Despite the substantial evidence base for the benefits of thromboprophylaxis this was used in only about half of eligible patients and many healthcare professionals seemed to be unaware of the risks.3 4 The National Institute for Health and Clinical Excellence (NICE) published guidance on the prevention of VTE for surgical patients in 2007.5 This article summarises the most recent recommendations from NICE on VTE prophylaxis for all patients in hospital.


    NICE recommendations are based on systematic reviews of best available evidence. When minimal evidence is available, recommendations are based on the Guideline Development Group’s experience and opinion of what constitutes good practice. Evidence levels for the recommendations are given in italic in square brackets. (See further information box for a description of the evidence and challenges in formulating recommendations for this guidance.)

    Assessing the risks of VTE and bleeding

    • Assess all patients on admission to identify those who are at increased risk of VTE. [Based on the experience and opinion of the Guideline Development Group (GDG)]

    • Regard medical patients as being at increased risk of VTE if one of the following applies:

      • - Expected to be bed bound, unable to walk unaided, or spend a substantial part of their day in bed or in a chair for three days or more.

      • - Expected to have ongoing reduced mobility relative to their normal state and have one or more of the risk factors shown in box 1. [Based on randomised controlled trials, observational studies, and the experience and opinion of the GDG]

    Box 1 Risk factors for venous thromboembolism (VTE)

    • Active cancer or cancer treatment

    • Age over 60 years

    • Admission to critical care

    • Dehydration

    • Known thrombophilia

    • Obesity (body mass index over 30 kg/m2)

    • One or more significant medical comorbidities (for example, heart disease; metabolic, endocrine, or respiratory pathologies; acute infectious diseases; inflammatory conditions)

    • Personal history or first degree relative with a history of VTE

    • Use of hormone replacement therapy

    • Use of oestrogen containing contraceptives

    • Varicose veins with phlebitis

    • Regard surgical patients and patients with trauma as being at increased risk of VTE if they meet one of the following criteria:

      • - Surgical procedure with a total anaesthetic and surgical time of more than 90 minutes or 60 minutes if the surgery involved the pelvis or lower limb.

      • - Acute surgical admission with inflammatory or intra-abdominal condition.

      • - Expected substantial reduction in mobility.

      • - Presence of one or more of the risk factors shown in box 1. [Based on randomised controlled trials, observational studies and the experience and opinion of the GDG]

    • Assess all patients for risk of bleeding before offering prophylactic drugs for VTE. Do not offer such prophylaxis to patients with any of the risk factors for bleeding shown in box 2, unless the risk of VTE outweighs the risk of bleeding. Prescribers should consult the summary of product characteristics for the prophylactic drug being used or planned for further details. [Based on the experience and opinion of the GDG]

    Box 2 Risk factors for bleeding

    • Active bleeding

    • Acquired bleeding disorders (such as acute liver failure)

    • Concurrent use of anticoagulants known to increase the risk of bleeding (such as warfarin with international normalised ratio (INR) higher than 2)

    • Lumbar puncture, epidural anaesthesia, or spinal anaesthesia expected within the next 12 hours

    • Lumbar puncture, epidural anaesthesia, or spinal anaesthesia within the previous four hours

    • Acute stroke, in line with NICE clinical guideline 68.6

    • Thrombocytopenia (platelets <75×109/l)

    • Uncontrolled systolic hypertension (≥230/120 mm Hg)

    • Untreated inherited bleeding disorders (such as haemophilia and von Willebrand’s disease)

    • Reassess patients’ risk of bleeding and VTE within 24 hours of admission and whenever the clinical situation changes, with the aim of:

      • - Ensuring that the methods of VTE prophylaxis being used are suitable.

      • - Ensuring that VTE prophylaxis is being used correctly.

      • - Identifying adverse events resulting from VTE prophylaxis. [Based on the experience and opinion of the GDG]

    Reducing the risk of VTE

    • Encourage patients to become mobile as soon as possible. [Based on the experience and opinion of the GDG]

    • Offer prophylactic drugs to general medical patients assessed to be at increased risk of VTE. Choose one of:

      • - Fondaparinux sodium.

      • - Low molecular weight heparin. At the time of publication some types do not have marketing authorisation in the United Kingdom for VTE prophylaxis in medical patients. Prescribers should consult the summary of product characteristics for the individual drug.

      • - Unfractionated heparin (for patients with renal failure).

    • Start prophylactic drugs as soon as possible after risk assessment has been completed. Continue until the patient is no longer at increased risk of VTE. [Based on high quality randomised controlled trials in medical and surgical populations]

    Patient information and planning for discharge

    • Before starting VTE prophylaxis, offer patients and their families or carers (if appropriate) verbal and written information on:

      • - The risks and possible consequences of VTE.

      • - The importance of VTE prophylaxis and its possible side effects.

      • - The correct use of VTE prophylaxis (such as antiembolism stockings, foot impulse devices, or intermittent pneumatic compression devices).

      • - How patients can reduce their risk of VTE (for example, by keeping well hydrated and, if possible, exercising and becoming more mobile). [Based on qualitative studies and the experience and opinion of the GDG]

    • As part of the discharge plan, offer patients and their families or carers (if appropriate) verbal and written information on:

      • - The signs and symptoms of deep vein thrombosis and pulmonary embolism.

      • - The correct and recommended duration of use of VTE prophylaxis at home (if discharged with prophylaxis)

      • - The importance of correct use of VTE prophylaxis at home (if discharged with prophylaxis) and its recommended duration.

      • - The signs and symptoms of adverse events related to VTE prophylaxis (if discharged with prophylaxis).

      • - The importance of seeking help and details of who to contact about problems with using the prophylaxis (if discharged with prophylaxis).

      • - The importance of seeking medical help and who to contact if deep vein thrombosis, pulmonary embolism, or another adverse event is suspected. [Based on qualitative studies and the experience and opinion of the GDG]

    Overcoming barriers

    Organisational and professional barriers exist to implementing this guidance. Most medical inpatients now arrive as direct urgent or emergency admissions. VTE prophylaxis stands the best chance of being effective the earlier it is delivered in the course of the illness and the period of immobilisation. This is sometimes overshadowed on admission, however, by clinical priorities of establishing a working diagnosis and instigating treatment of the most pressing problems. Nonetheless, a provisional plan for VTE prophylaxis can be made simultaneously, on the basis of an individualised risk assessment, and reviewed appropriately. This should be done using the Department of Health’s national VTE risk assessment template.7

    The professional obstacles are related to differing perceptions of risk. Anticoagulation in any form carries a risk of bleeding; if this complication occurs, the prescriber may feel a sense of responsibility and may prescribe anticoagulation less readily in the future. In contrast, thromboembolic events do not have an evident effect on subsequent prescribing.8 Orthopaedic surgeons have been the most concerned about bleeding risks because non-life threatening bleeding may set in train disastrous postoperative complications after joint and limb surgery.9 Thus a representative panel of seven orthopaedic surgeons was involved at every stage of developing these guidelines.

    Further information on guidance

    Because of concerns about the bleeding risk, expressed in a series of meetings between representatives of NICE and the British Orthopaedic Association, many orthopaedic surgeons have been reluctant to use heparin for venous thromboprophylaxis. Practice has varied, and some surgeons prefer to use aspirin rather than anticoagulants. Others believe that VTE is less of a problem because of the trend for early mobilisation and discharge. This opinion has an inherent ambiguity, however—early discharge may mean that surgeons see VTE less often, but the complication may still occur as often. British orthopaedic surgeons are not alone in their concern about increasing pressure to prescribe all patients “potent anticoagulants.” Also critical of the latest guidance from the American College of Chest Physicians,10 American Academy of Orthopedic Surgeons (AAOS) released their own guidance for their colleagues.11 In a riposte, thrombosis researchers from McMaster University wrote “The AAOS panel ignored the randomized data demonstrating that thromboprophylaxis reduces both DVT [deep vein thrombosis] and PE [pulmonary embolism], and many of their recommendations are based on expert opinion and lack a scientific basis.”12


    The Guideline Development Group followed standard NICE methodology in the development of this guideline ( The group included two patient representatives, two nurses, a general medical and critical care physician, an epidemiologist, a respiratory physician, a haematologist, a clinical pharmacologist, an orthopaedic surgeon, a palliative medicine physician, a vascular surgeon, and a cardiothoracic surgeon. Systematic reviewers, health economists, and information scientists provided technical support. Seven additional orthopaedic surgeons and one patient representative advised the group on orthopaedic surgery, and the group also obtained expert advice on statistics, general practice, anaesthesia, neurosurgery, haematology, obstetrics, and spinal surgery.

    More than 400 randomised trials have investigated VTE prophylaxis—a greater quantity of high quality evidence than is available in many other areas of clinical practice. Such evidence is essential because the competing risks of venous thromboembolism and of bleeding need to be balanced. Serious events attributable to either are uncommon, and experience alone is not a useful basis for recommendations. In spite of the many trials examining interventions for thromboprophylaxis, many practical recommendations required GDG opinion to guide formulation.

    Future research

    The NICE guidance identifies five research questions, which in brief are:

    • What is the absolute risk of VTE in different groups of patients admitted to hospital?

    • How clinically effective and cost effective are pharmacological, mechanical, and combined prophylaxis for medical patients?

    • Should prophylactic drugs be offered to patients with lower limb plaster casts?

    • What are the risks and benefits of low molecular weight heparin and fondaparinux sodium for patients with acute stroke?

    • What is the incidence of post-thrombotic syndrome after deep vein thrombosis?


    Cite this as: BMJ 2010;340:c95


    • This is one of a series of BMJ summaries of new guidelines, which are based on the best available evidence; they highlight important recommendations for clinical practice, especially where uncertainty or controversy exists.

    • Members of the Guideline Development Group: Anayo Akunne, Nina Balachander, John Browne, Kim Carter, Simon Carter, Lee-Yee Chong, Nick Fiddian, Simon Frostick, Nandan Gautam, Paul Gregg, Karen Head, Aroon Hingorani, Kate Homer, Rodney Hughes, Beverley Hunt, Nigel Langford, Hanna Lewin, Paul Mainwaring, Donald McBride, Gordon McPherson, Simon Noble, Carlos Sharpin, Nicola Sloan, Gerard Stansby, Peter Walton, David Warwick, Nick Welch, David Wonderling, Annie Young, and Claire Young.

    • Contributors: TT and JH both contributed to a first draft that followed the template agreed by the BMJ and NICE and they shared in the subsequent editing. TT is guarantor.

    • Funding: The National Clinical Guideline Centre for Acute and Chronic Conditions was commissioned and funded by the National Institute for Health and Clinical Excellence to write this summary.

    • Competing interests: All authors have completed the Unified Competing Interest form at (available on request from the corresponding author) and declare (1) JH and TT have support from NICE for work on guideline development: JH and her department are funded by NICE and TT receives honorariums for chairing the guideline development meetings; (2) no relationships with any company that might have an interest in the submitted work; (3) no spouses, partners, or children have financial relationships that may be relevant to the submitted work; and (4) no non-financial interests that may be relevant to the submitted work.”

    • Provenance and peer review: Commissioned; not externally peer reviewed.