Guideline:Venous thromboembolism: reducing the risk. Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients admitted to hospital. Measure Summary

Venous thromboembolism (deep vein thrombosis and pulmonary embolism)

To provide evidence-based recommendations on reducing the risk of venous thromboembolism (VTE) in patients admitted to hospital

Primary Outcomes

• Deep-vein thrombosis (DVT)
• Proximal DVT
• Pulmonary embolism
• Major bleeding events
• Mortality

Secondary Outcomes

• Post-thrombotic syndrome (PTS)
• Chronic thromboembolic pulmonary hypertension (CTEPH)
• Heparin-induced thrombocytopenia (HIT)
• Neurological events
• Quality of life
• Survival
• Length of hospital stay

Note from the National Guideline Clearinghouse (NGC): This guideline was developed by the National Collaborating Centre for Acute and Chronic Conditions (NCC-ACC) on behalf of the National Institute for Health and Clinical Excellence (NICE). See the "Availability of Companion Documents" field for the full version of this guidance.

Developing the Clinical Questions

Clinical questions were developed to guide the literature searching process and to facilitate the development of recommendations by the guideline development group. The clinical questions were initially drafted by the review team and were refined and validated by the Guideline Development Group (GDG). The questions were based on the scope (see Appendix A in the full version of the guideline).

Clinical Literature Search

The aim of the literature search was to find evidence within the published literature in order to answer the clinical questions identified. Clinical databases were searched using filters (or hedges), using relevant medical subject headings and free-text terms. Non-English studies and abstracts were not reviewed. Searches were conducted to update the previous guideline. Each database was searched up to 10 December 2008. One initial search was performed and then two update searches nearer the end of guideline development period. No papers after this date were considered.

The search strategies can be found in Appendix C in the full guideline document.

The following databases were searched:

• The Cochrane Library up to Issue 4 2008
• Medline 1950-2008 (OVID)
• EMBASE 1980-2008 (OVID)
• CINAHL 1982-2008 (NLH Search 2.0)
• Health Economic and Evaluations Database (HEED) up to December 2008

There was no systematic attempt to search for grey literature or unpublished literature although all stakeholder references were followed up. We searched for guidelines and reports via relevant websites including those listed below.

• Members of the Guidelines International Network's Web sites (http://www.g-i-n.net/ )
• National Institute of Health and Clinical Excellence (NICE) (www.nice.org.uk )
• National Library for Health (NLH) (http://www.library.nhs.uk/ )
• National Institutes of Health Consensus Development Program (http://consensus.nih.gov/ )
• New Zealand Guidelines Development Group (NZGG) (http://www.nzgg.org.nz/ )
• Scottish Intercollegiate Guideline Network (SIGN) (www.sign.ac.uk )
• National Guideline Clearinghouse (www.guideline.gov )

Literature Review for Health Economics

We obtained published economic evidence from a systematic search of the following databases:

• The Cochrane Library up to Issue 4 2008
• Medline 1950-2008 (OVID)
• EMBASE 1980-2008 (OVID)
• Health Economic and Evaluations Database (HEED) up to December 2008

The information specialists used the same search strategy as for the clinical questions, using an economics filter in the place of a systematic review or randomised controlled trial filter. Each database was searched from its start date up to December 2008. Papers identified after this date were not considered. Search strategies can be found in Appendix C of the full version of the guideline.

Papers were excluded from the review and evidence tables if:

• The population and interventions were covered by an original guideline cost-effectiveness analysis.
• The study did not contain any original data on cost or cost-effectiveness (that is, it was a review or a clinical paper).
• The analysis was not incremental and was not described adequately to allow incremental analysis (so studies reporting only average cost-effectiveness ratios were excluded unless they provided data to allow the calculation of incremental cost-effectiveness ratios).
• Cost analyses were excluded if the results were not presented in a way that would allow the incremental cost per patient to be extracted or derived.

Not stated

Levels of Evidence for Intervention Studies

1++ High-quality meta-analyses, systematic reviews of randomised controlled trials (RCTs) or RCTs with a very low risk of bias

1+ Well-conducted meta-analyses, systematic reviews of RCTs, or RCTs with a low risk of bias

1– Meta-analyses, systematic reviews of RCTs, or RCTs with a high risk of bias

2++ High-quality systematic reviews of case–control or cohort studies. High-quality case–control or cohort studies with a very low risk of confounding, bias or chance and a high probability that the relationship is causal

2+ Well-conducted case–control or cohort studies with a low risk of confounding, bias or chance and a moderate probability that the relationship is causal

2– Case–control or cohort studies with a high risk of confounding, bias, or chance and a significant risk that the relationship is not causal

3 Non-analytical studies (e.g., case reports, case series)

4 Expert opinion, formal consensus

Note from the National Guideline Clearinghouse (NGC): This guideline was developed by the National Collaborating Centre for Acute and Chronic Conditions (NCC-ACC) on behalf of the National Institute for Health and Clinical Excellence (NICE). See the "Availability of Companion Documents" field for the full version of this guidance.

Literature Reviewing Process

References identified by the systematic literature search were screened for appropriateness by title and abstract by an information scientist and systematic reviewer. Studies were selected that reported one or more venous thromboembolism (VTE) outcome (deep venous thrombosis [DVT], pulmonary embolism [PE]) determined by objective/reliable methods. We did not select studies that reported only major bleeding outcomes, but where an included systematic review reported such studies, they were not removed. The guideline development group also suggested further references and we assessed these in the same way. Selected studies were ordered and assessed in full by a systematic reviewer using agreed inclusion/exclusion criteria specific to the guideline topic, and using NICE methodology quality assessment checklists appropriate to the study design. These are described in the NICE guidelines manual.

Literature Review for Patient View Studies

Information of patient views regarding thromboprophylaxis and adherence are often more appropriately studied using non-randomized controlled trial (RCT) designs (i.e., qualitative studies, surveys of patients in observational studies). Unlike interventional studies, there is no established hierarchy of evidence to answer questions on patient views; observational or qualitative designs are not necessarily of lower quality than RCTs. Therefore, no study design limitation was included in the search and review of evidence. Relevant studies where the methods were clearly reported, appropriately designed to answer the study questions and met the quality assessment were included.

Qualitative studies were quality assessed using checklists from the NICE guideline manual and only studies rated as '+' or '++' were included.

The questionnaires used in the various patient view studies found in our searches did not report on how they were designed and validated. This is a major methodological limitation for all studies using questionnaires in this guideline.

It is also important to note that both RCTs and observational studies of patient adherence come with potential biases and limitations. For example, the informed consent process and strict inclusion criteria of RCTs may contribute to better informed or motivated patients. In addition, participation in RCTs is usually associated with closer monitoring and better level of support. This may result in higher adherence than may be expected in routine practise. Adherence may also be higher in studies where patients were checked hourly for adherence or where self-reports were used. However, when a range of results are observed in different study designs and settings, these provide a useful indication of the types of issues that might be expected from the interventions in usual practice.

Methods for Combining Direct Evidence

Where possible, meta-analyses were conducted to combine the results of studies addressing the same clinical question using Cochrane's Review Manager Software. Random effects method (Der Simonian and Laird model) was used to calculate risk ratios (relative risk) of an event occurring, that is, all cause mortality, DVT, PE or major bleeding. Statistical heterogeneity was assessed by considering the chi-squared and the I-squared test. Significant heterogeneity was noted for any study where the I-squared value was >50%, or the I-squared value was between 25% and 50% and the chi-squared value was p <0.1. We carried out sensitivity analyses to identify studies whose results were heterogeneous to the overall result. Any such studies were further assessed to identify any clinical or methodological causes. We avoided removing these studies from the meta-analyses unless we identified a serious methodological flaw, as removal would introduce bias into the systematic review.

Where combining results of trials in a meta-analysis was not appropriate a narrative synthesis of studies was undertaken.

Methods for Combining Direct and Indirect Evidence

It is difficult to determine the most effective prophylaxis strategy from the results of conventional meta-analyses of direct evidence for three reasons:

• Some pairs of alternative strategies have not been directly compared in an RCT (for example, aspirin vs. fondaparinux).
• Sometimes the direct evidence does not provide enough data and we need to support it with indirect evidence.
• There are frequently multiple overlapping comparisons (For example, heparin vs. no prophylaxis, heparin vs. stockings and stockings vs. no prophylaxis), that potentially give inconsistent estimates of effect.

To overcome these problems, a network meta-analysis (NMA) was conducted that simultaneously pools together all the data. This allowed us to rank the different prophylaxis interventions in order of efficacy at reducing DVTs and PEs and in order of risk of major bleeding. For each of these two outcomes, it gives us a single estimate of effect (with confidence intervals) for each intervention compared with no prophylaxis.

Note from the National Guideline Clearinghouse (NGC): This guideline was developed by the National Collaborating Centre for Acute and Chronic Conditions (NCC-ACC) on behalf of the National Institute for Health and Clinical Excellence (NICE). See the "Availability of Companion Documents" field for the full version of this guidance.

A multidisciplinary Guideline Development Group (GDG) comprising professional group members and consumer representatives of the main stakeholders developed this guideline (see section on Guideline Development Group Membership and acknowledgements in the full version of the guideline).

NICE funds the National Clinical Guideline Centre for Acute and Chronic Conditions, NCGC (formerly the National Collaborating Centre for Acute Care, NCC-AC) and thus supported the development of this guideline. The Guideline Development Group was convened by the NCC-AC and chaired by Professor Tom Treasure in accordance with guidance from NICE.

The group met every 6-8 weeks during the development of the guideline.

Staff from the NCGC provided methodological support and guidance for the development process. They undertook systematic searches, retrieval and appraisal of the evidence and drafted the guideline. The glossary to the guideline contains definitions of terms used by staff and the GDG.

Development of Recommendations

Over the course of the guideline development process the GDG was presented with the following:

• Evidence tables and narrative summaries of the clinical evidence reviewed. All evidence tables are in Appendix D of the full version of the guideline (see "Availability of Companion Documents" field).
• Forest plots of direct meta-analysis (Appendix E of the full version of the guideline)
• Forest plots of network meta-analysis (Chapters 9-12, 23 of the full version of the guideline)
• A description of the methods for, and results of, the cost-effectiveness analysis (Chapter 4 and Chapters 9-12, 23 of the full version of the guideline)

Although evidence was reviewed for every population, network meta-analysis and cost effectiveness analysis were only conducted for 5 populations, general medical patients, general surgical patients, hip fracture surgery, total hip replacement and total knee replacement. For these populations the recommendations were derived directly from the results of the analyses. If the decision was taken not to recommend the most cost effective strategy the GDG clearly explained their reasoning for this.

For populations which did not have cost effectiveness models conducted, recommendations were based on the direct evidence available for that population and from extrapolating the results from cost-effectiveness models in other populations. The link between evidence and the subsequent recommendations is explained in the relevant sections.

Not applicable

Health Economic Methods

It is important to investigate whether health services are cost-effective (that is, value for money). If a particular prophylaxis or treatment strategy were found to yield little health gain relative to the resources used, then it would be advantageous to re-deploy resources to other activities that yield greater health gain.

In the previous National Institute for Health and Clinical Excellence (NICE) guideline great inconsistency was found in the economic evaluations in the published literature. This was mainly because the evaluations varied in the clinical studies they included and because they used crude methods to deal with indirect evidence. Furthermore most of the published studies did not evaluate cost-effectiveness using NICE's reference case. Therefore in this guideline an original cost-effectiveness analysis was performed which compared a variety of different prophylactic strategies for a number of different hospital population subgroups. In addition, a systematic review of the economic literature was conducted for populations or interventions not covered by the original cost-effectiveness analysis.

The criteria applied for an intervention to be considered cost-effective were either:

1. The intervention dominated other relevant strategies (that is, it is both less costly in terms of resource use and more clinically effective compared with all the other relevant alternative strategies), or
2. The intervention cost less than 20,000 pounds per quality-adjusted life-year (QALY) gained compared with the next best strategy (and compared with no prophylaxis).

The full economic evaluation of any strategy has to be in comparison with another strategy. Hence we refer to:

• Incremental cost: the mean cost of one strategy minus the mean cost of a comparator study
• QALYs gained: the mean QALYs associated with one strategy minus the mean QALYs of a comparator study
• Incremental cost-effectiveness ratio: the incremental cost divided by the respective QALYs gained
• Incremental net benefit (INB): the (monetary) value of a strategy compared with an alternative strategy for a given cost-effectiveness threshold (For example: 20,000 pounds per QALY gained).

In our own cost-effectiveness analysis (Chapter 4 of the full version of the guideline), we use the following formula to estimate the INB of each strategy:

INB = (QALYs gained compared with no prophylaxis x 20,000 pounds) minus the incremental cost compared with no prophylaxis.

This indicates that we will invest up to 20,000 pounds to gain one additional QALY. The strategy that has the highest INB is the optimal (that is, most cost-effective) strategy. Strategies that have a negative INB are not cost-effective even compared with no prophylaxis.

Cost-effectiveness Modelling

The following general principles were adhered to:

• The guideline development group (GDG) was consulted during the construction and interpretation of the model.
• The model was based on a network meta-analysis derived from the systematic review of clinical evidence.
• Model assumptions were reported fully and transparently (Chapter 4 in the full version of the guideline).
• The results were subject to thorough sensitivity analysis and limitations discussed.
• Costs were calculated from a health services perspective.

The guideline was validated through two consultations.

1. The first draft of the guideline (The full guideline, National Institute for Health and Clinical Excellence [NICE] guideline and Quick Reference Guide) were consulted with stakeholders and comments were considered by the Guideline Development Group (GDG).
2. The final consultation draft of the full guideline, the NICE guideline and the Information for the Public were submitted to stakeholders for final comments.

The final draft was submitted to the Guideline Review Panel for review prior to publication.

Note from the National Guideline Clearinghouse (NGC): This guideline was developed by the National Collaborating Centre for Acute and Chronic Conditions (NCC-ACC) on behalf of the National Institute for Health and Clinical Excellence (NICE). See the "Availability of Companion Documents" field for the full version of this guidance.

Assessing the Risks of Venous Thromboembolism (VTE) and Bleeding

Assess all patients on admission to identify those who are at increased risk of VTE.

Regard medical patients as being at increased risk of VTE if they:

• Have had or are expected to have significantly reduced mobility for 3 days or more or
• Are expected to have ongoing reduced mobility relative to their normal state and have one or more of the risk factors shown in Box 1.

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 involves the pelvis or lower limb
• Acute surgical admission with inflammatory or intra-abdominal condition
• Expected significant reduction in mobility
• One or more of the risk factors shown in Box 1

Assess all patients for risk of bleeding before offering pharmacological VTE prophylaxis. Do not offer pharmacological VTE 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.

Reassess patients' risks of bleeding and VTE within 24 hours of admission and whenever the clinical situation changes, to:

• Ensure that the methods of VTE prophylaxis being used are suitable
• Ensure that VTE prophylaxis is being used correctly
• Identify adverse events resulting from VTE prophylaxis

Reducing the Risk of VTE

• Do not allow patients to become dehydrated unless clinically indicated.
• Encourage patients to mobilize as soon as possible.
• Do not regard aspirin or other antiplatelet agents as adequate prophylaxis for VTE.
• Consider offering temporary inferior vena caval filters to patients who are at very high risk of VTE (such as patients with a previous VTE event or an active malignancy) and for whom mechanical and pharmacological VTE prophylaxis are contraindicated.

Using VTE Prophylaxis

Mechanical VTE Prophylaxis

Base the choice of mechanical VTE prophylaxis on individual patient factors including clinical condition, surgical procedure and patient preference. Choose any one of:

• Anti-embolism stockings (thigh or knee length)
• Foot impulse devices
• Intermittent pneumatic compression devices (thigh or knee length)

Anti-Embolism Stockings

Do not offer anti-embolism stockings to patients who have:

• Suspected or proven peripheral arterial disease
• Peripheral arterial bypass grafting
• Peripheral neuropathy or other causes of sensory impairment
• Any local conditions in which stockings may cause damage, for example fragile 'tissue paper' skin, dermatitis, gangrene or recent skin graft
• Known allergy to material of manufacture
• Cardiac failure
• Severe leg oedema or pulmonary oedema from congestive heart failure
• Unusual leg size or shape
• Major limb deformity preventing correct fit

Use caution and clinical judgement when applying anti-embolism stockings over venous ulcers or wounds.

Ensure that patients who need anti-embolism stockings have their legs measured and that the correct size of stocking is provided. Anti-embolism stockings should be fitted and patients shown how to use them by staff trained in their use.

Ensure that patients who develop oedema or postoperative swelling have their legs re-measured and anti-embolism stockings refitted.

If arterial disease is suspected, seek expert opinion before fitting anti-embolism stockings.

Use anti-embolism stockings that provide graduated compression and produce a calf pressure of 14–15 mmHg.

Encourage patients to wear their anti-embolism stockings day and night until they no longer have significantly reduced mobility.

Remove anti-embolism stockings daily for hygiene purposes and to inspect skin condition. In patients with a significant reduction in mobility, poor skin integrity or any sensory loss, inspect the skin two or three times per day, particularly over the heels and bony prominences.

Discontinue the use of anti-embolism stockings if there is marking, blistering or discolouration of the skin, particularly over the heels and bony prominences, or if the patient experiences pain or discomfort. If suitable, offer a foot impulse or intermittent pneumatic compression device as an alternative.

Show patients how to use anti-embolism stockings correctly and ensure they understand that this will reduce their risk of developing VTE.

Monitor the use of anti-embolism stockings and offer assistance if they are not being worn correctly.

Foot Impulse Devices and Intermittent Pneumatic Compression Devices

Do not offer foot impulse or intermittent pneumatic compression devices to patients with a known allergy to the material of manufacture.

Encourage patients on the ward who have foot impulse or intermittent pneumatic compression devices to use them for as much of the time as is possible and practical, both when in bed and when sitting in a chair.

Pharmacological VTE Prophylaxis

Base the choice of pharmacological VTE agents on local policies and individual patient factors, including clinical condition (such as renal failure) and patient preferences.

Medical Patients

General Medical Patients

Offer pharmacological VTE prophylaxis to general medical patients assessed to be at increased risk of VTE. Choose any one of:

• Fondaparinux sodium
• Low molecular weight heparin (LMWH)*
• Unfractionated heparin (UFH) (for patients with renal failure)

Start pharmacological VTE prophylaxis as soon as possible after risk assessment has been completed. Continue until the patient is no longer at increased risk of VTE.

Patients with Stroke

Do not offer anti-embolism stockings for VTE prophylaxis to patients who are admitted for stroke.

Consider offering prophylactic-dose LMWH* (or UFH for patients with renal failure) if:

• A diagnosis of haemorrhagic stroke has been excluded, and
• The risk of bleeding (haemorrhagic transformation of stroke or bleeding into another site) is assessed to be low, and
• The patient has one or more of:
  • Major restriction of mobility
  • Previous history of VTE
  • Dehydration
  • Comorbidities (such as malignant disease).

  Continue until the acute event is over and the patient's condition is stable.

Until the patient can have pharmacological VTE prophylaxis, consider offering a foot impulse or intermittent pneumatic compression device.

Patients with Cancer

Offer pharmacological VTE prophylaxis to patients with cancer who are assessed to be at increased risk of VTE. Choose any one of:

• Fondaparinux sodium
• LMWH*
• UFH (for patients with renal failure)

  Start pharmacological VTE prophylaxis as soon as possible after risk assessment has been completed. Continue until the patient is no longer at increased risk of VTE.

Do not routinely offer pharmacological or mechanical VTE prophylaxis to patients with cancer having oncological treatment who are ambulant.

Patients with Central Venous Catheters

• Do not routinely offer pharmacological or mechanical VTE prophylaxis to patients with central venous catheters who are ambulant.
• Consider offering pharmacological VTE prophylaxis with LMWH* (or UFH for patients with renal failure) to patients with central venous catheters who are at increased risk of VTE.

Patients in Palliative Care

Consider offering pharmacological VTE prophylaxis to patients in palliative care who have potentially reversible acute pathology. Take into account potential risks and benefits and the views of patients and their families and/or carers. Choose any one of:

• Fondaparinux sodium
• LMWH*
• UFH (for patients with renal failure)

Do not routinely offer pharmacological or mechanical VTE prophylaxis to patients admitted for terminal care or those commenced on an end-of-life care pathway.

Review decisions about VTE prophylaxis for patients in palliative care daily, taking into account the views of patients, their families and/or carers and the multidisciplinary team.

*At the time of publication (January 2010) some types of LMWH do not have UK marketing authorisation for VTE prophylaxis in medical patients. Prescribers should consult the summary of product characteristics for the individual LMWH. Informed consent for off label use should be obtained and documented.

Medical Patients in Whom Pharmacological VTE Prophylaxis Is Contraindicated

Consider offering mechanical VTE prophylaxis to medical patients in whom pharmacological VTE prophylaxis is contraindicated. Choose any one of:

• Anti-embolism stockings (thigh or knee length)
• Foot impulse devices
• Intermittent pneumatic compression devices (thigh or knee length)

Surgical Patients

All Surgery

Advise patients to consider stopping oestrogen-containing oral contraceptives or hormone replacement therapy 4 weeks before elective surgery. If stopped, provide advice on alternative contraceptive methods.

Assess the risks and benefits of stopping pre-existing established antiplatelet therapy 1 week before surgery. Consider involving the multidisciplinary team in the assessment.

Consider regional anaesthesia for individual patients, in addition to other methods of VTE prophylaxis, as it carries a lower risk of VTE than general anaesthesia. Take into account patients' preferences, their suitability for regional anaesthesia and any other planned method of VTE prophylaxis.

If regional anaesthesia is used, plan the timing of pharmacological VTE prophylaxis to minimise the risk of epidural haematoma. If antiplatelet or anticoagulant agents are being used, or their use is planned, refer to the summary of product characteristics for guidance about the safety and timing of these agents in relation to the use of regional anaesthesia.

Do not routinely offer pharmacological or mechanical VTE prophylaxis to patients undergoing a surgical procedure with local anaesthesia by local infiltration with no limitation of mobility.

Cardiac

Offer VTE prophylaxis to patients undergoing cardiac surgery who are not having other anticoagulation therapy and are assessed to be at increased risk of VTE.

• Start mechanical VTE prophylaxis at admission. Choose any one of:
  • Anti-embolism stockings (thigh or knee length)
  • Foot impulse device
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Add pharmacological VTE prophylaxis for patients who have a low risk of major bleeding, taking into account individual patient factors and according to clinical judgement. Choose one of:
  • LMWH
  • UFH (for patients with renal failure)

  Continue pharmacological VTE prophylaxis until the patient no longer has significantly reduced mobility (generally 5–7 days).

Gastrointestinal, Gynaecological, Thoracic and Urological

Offer VTE prophylaxis to patients undergoing bariatric surgery.

• Start mechanical VTE prophylaxis at admission. Choose any one of:
  • Anti-embolism stockings (thigh or knee length)
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Add pharmacological VTE prophylaxis for patients who have a low risk of major bleeding, taking into account individual patient factors and according to clinical judgement. Choose any one of:
  • Fondaparinux sodium
  • LMWH
  • UFH (for patients with renal failure)

  Continue pharmacological VTE prophylaxis until the patient no longer has significantly reduced mobility (generally 5–7 days).

Offer VTE prophylaxis to patients undergoing gastrointestinal surgery who are assessed to be at increased risk of VTE.

• Start mechanical VTE prophylaxis at admission. Choose any one of:
  • Anti-embolism stockings (thigh or knee length)
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length).

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Add pharmacological VTE prophylaxis for patients who have a low risk of major bleeding, taking into account individual patient factors and according to clinical judgement. Choose any one of:
  • Fondaparinux sodium
  • LMWH
  • UFH (for patients with renal failure)

  Continue pharmacological VTE prophylaxis until the patient no longer has significantly reduced mobility (generally 5–7 days).

Offer VTE prophylaxis to patients undergoing gynaecological, thoracic or urological surgery who are assessed to be at increased risk of VTE.

• Start mechanical VTE prophylaxis at admission. Choose any one of:
  • Anti-embolism stockings (thigh or knee length)
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Add pharmacological VTE prophylaxis for patients who have a low risk of major bleeding, taking into account individual patient factors and according to clinical judgement. Choose one of:
  • LMWH
  • UFH (for patients with renal failure)

  Continue pharmacological VTE prophylaxis until the patient no longer has significantly reduced mobility (generally 5–7 days).

Extend pharmacological VTE prophylaxis to 28 days postoperatively for patients who have had major cancer surgery in the abdomen or pelvis.

Neurological (Cranial or Spinal)

Offer VTE prophylaxis to patients undergoing cranial or spinal surgery who are assessed to be at increased risk of VTE.

• Start mechanical VTE prophylaxis at admission. Choose any one of:
  • Anti-embolism stockings (thigh or knee length)
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Add pharmacological VTE prophylaxis for patients who have a low risk of major bleeding, taking into account individual patient factors and according to clinical judgement. Choose one of:
  • LMWH
  • UFH (for patients with renal failure)

  Continue pharmacological VTE prophylaxis until the patient no longer has significantly reduced mobility (generally 5–7 days).

Do not offer pharmacological VTE prophylaxis to patients with ruptured cranial or spinal vascular malformations (for example, brain aneurysms) or acute traumatic or non-traumatic haemorrhage until the lesion has been secured or the condition is stable.

Orthopaedic Surgery – Elective Hip Replacement, Elective Knee Replacement and Hip Fracture

The summaries of product characteristics state postoperative start times for dabigatran, rivaroxaban and fondaparinux, and preoperative start times for most LMWHs, although individual start times vary depending on the specific LMWH. In this guideline it is recommended that LMWH is started postoperatively, which is off-label use, because of concerns about the risk of bleeding into the joint. Patients would be protected preoperatively by mechanical VTE prophylaxis.

Elective Hip Replacement

Offer combined VTE prophylaxis with mechanical and pharmacological methods to patients undergoing elective hip replacement surgery.

• Start mechanical VTE prophylaxis at admission. Choose any one of the following, based on individual patient factors:
  • Anti-embolism stockings (thigh or knee length), used with caution
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Provided there are no contraindications, start pharmacological VTE prophylaxis after surgery. Choose any one of:
  • Dabigatran etexilate, starting 1–4 hours after surgery*
  • Fondaparinux sodium, starting 6 hours after surgical closure provided haemostasis has been established
  • LMWH, starting 6–12 hours after surgery
  • Rivaroxaban, starting 6–10 hours after surgery**
  • UFH (for patients with renal failure), starting 6–12 hours after surgery

  Continue pharmacological VTE prophylaxis for 28–35 days, according to the summary of product characteristics for the individual agent being used.

Elective Knee Replacement

Offer combined VTE prophylaxis with mechanical and pharmacological methods to patients undergoing elective knee replacement surgery.

• Start mechanical VTE prophylaxis at admission. Choose any one of the following, based on individual patient factors:
  • Anti-embolism stockings (thigh or knee length), used with caution
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Provided there are no contraindications, start pharmacological VTE prophylaxis after surgery. Choose any one of:
  • Dabigatran etexilate, starting 1–4 hours after surgery*
  • Fondaparinux sodium, starting 6 hours after surgical closure provided haemostasis has been established
  • LMWH, starting 6–12 hours after surgery
  • Rivaroxaban, starting 6–10 hours after surgery**
  • UFH (for patients with renal failure), starting 6–12 hours after surgery

  Continue pharmacological VTE prophylaxis for 10–14 days, according to the summary of product characteristics for the individual agent being used.

*In line with Dabigatran etexilate for the prevention of venous thromboembolism after hip or knee replacement surgery in adults (see the National Guideline Clearinghouse [NGC] summary of National Institute for Health and Clinical Excellence [NICE] technology appraisal guidance 157), dabigatran etexilate, within its marketing authorisation, is recommended as an option for the primary prevention of venous thromboembolic events in adults who have undergone elective total hip replacement surgery or elective total knee replacement surgery.

**In line with Rivaroxaban for the prevention of venous thromboembolism after total hip or total knee replacement in adults (see the NGC summary of NICE technology appraisal guidance 170), rivaroxaban, within its marketing authorisation, is recommended as an option for the prevention of venous thromboembolism in adults having elective total hip replacement surgery or elective total knee replacement surgery.

Hip Fracture

Offer combined VTE prophylaxis with mechanical and pharmacological methods to patients undergoing hip fracture surgery.

• Start mechanical VTE prophylaxis at admission. Choose any one of the following, based on individual patient factors:
  • Anti-embolism stockings (thigh or knee length), used with caution
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Provided there are no contraindications, add pharmacological VTE prophylaxis. Choose any one of:
  • Fondaparinux sodium, starting 6 hours after surgical closure, provided haemostasis has been established and there is no risk of bleeding (see Box 2, above)
  • LMWH, starting at admission, stopping 12 hours before surgery and restarting 6–12 hours after surgery
  • UFH (for patients with renal failure), starting at admission, stopping 12 hours before surgery and restarting 6–12 hours after surgery.

  Continue pharmacological VTE prophylaxis for 28–35 days, according to the summary of product characteristics for the individual agent being used.

Fondaparinux sodium is not recommended for use preoperatively for patients undergoing hip fracture surgery. If it has been used preoperatively it should be stopped 24 hours before surgery and restarted 6 hours after surgical closure, provided haemostasis has been established and there is no risk of bleeding (see Box 2, above).

Other Orthopaedic Surgery

Consider offering combined VTE prophylaxis with mechanical and pharmacological methods to patients having orthopaedic surgery (other than hip replacement, knee replacement or hip fracture surgery) based on an assessment of risks (see section 1.1 in the full version of the guideline) and after discussion with the patient.

• Start mechanical VTE prophylaxis at admission. Choose one of the following, based on individual patient factors:
  • Anti-embolism stockings (thigh or knee length), used with caution
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Start pharmacological VTE prophylaxis 6–12 hours after surgery. Choose one of:
  • LMWH
  • UFH (for patients with renal failure)

  Continue pharmacological VTE prophylaxis until the patient no longer has significantly reduced mobility.

Do not routinely offer VTE prophylaxis to patients undergoing upper limb surgery. If a patient is assessed to be at increased risk of VTE.

Vascular

Offer VTE prophylaxis to patients undergoing vascular surgery who are not having other anticoagulant therapy and are assessed to be at increased risk of VTE (see section 1.1). If peripheral arterial disease is present, seek expert opinion before fitting anti-embolism stockings.

• Start mechanical VTE prophylaxis at admission. Choose any one of:
  • Anti-embolism stockings (thigh or knee length)
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Add pharmacological VTE prophylaxis for patients who have a low risk of major bleeding, taking into account individual patient factors and according to clinical judgement. Choose one of:
  • LMWH
  • UFH (for patients with renal failure)

  Continue pharmacological VTE prophylaxis until the patient no longer has significantly reduced mobility (generally 5–7 days).

Day Surgery

Offer VTE prophylaxis to patients undergoing day surgery who are assessed to be at increased risk of VTE.

• Start mechanical VTE prophylaxis at admission. Choose any one of:
  • Anti-embolism stockings (thigh or knee length)
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Add pharmacological VTE prophylaxis for patients who have a low risk of major bleeding, taking into account individual patient factors and according to clinical judgement. Choose any one of:
  • Fondaparinux
  • LMWH
  • UFH (for patients with renal failure)

  If the patient is expected to have significantly reduced mobility after discharge, continue pharmacological VTE prophylaxis, generally for 5–7 days.

Other Surgical Patients

Offer VTE prophylaxis to patients undergoing surgery who are assessed to be at increased risk of VTE.

• Start mechanical VTE prophylaxis at admission. Choose any one of:
  • Anti-embolism stockings (thigh or knee length)
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• Add pharmacological VTE prophylaxis for patients who have a low risk of major bleeding, taking into account individual patient factors and according to clinical judgement. Choose one of:
  • LMWH
  • UFH (for patients with renal failure)

  Continue pharmacological VTE prophylaxis until the patient no longer has significantly reduced mobility (generally 5–7 days).

Other Patient Groups

Major Trauma

Offer combined VTE prophylaxis with mechanical and pharmacological methods to patients with major trauma. Regularly reassess the patient's risks of VTE and bleeding.

• Start mechanical VTE prophylaxis at admission or as early as clinically possible. Choose any one of:
  • Anti-embolism stockings (thigh or knee length), used with caution
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• If the benefits of reducing the risk of VTE outweigh the risks of bleeding (see Box 2, above) and the bleeding risk has been established as low, add pharmacological VTE prophylaxis. Choose one of:
  • LMWH
  • UFH (for patients with renal failure)

  Continue pharmacological VTE prophylaxis until the patient no longer has significantly reduced mobility.

Spinal Injury

Offer combined VTE prophylaxis with mechanical and pharmacological methods to patients with spinal injury. Regularly reassess the patient's risks of VTE and bleeding.

• Start mechanical VTE prophylaxis at admission or as early as clinically possible. Choose any one of:
  • Anti-embolism stockings (thigh or knee length), used with caution
  • Foot impulse devices
  • Intermittent pneumatic compression devices (thigh or knee length)

  Continue mechanical VTE prophylaxis until the patient no longer has significantly reduced mobility.

• If the benefits of reducing the risk of VTE outweigh the risks of bleeding (see Box 2, above) and the bleeding risk has been established as low, add pharmacological VTE prophylaxis. Choose one of:
  • LMWH
  • UFH (for patients with renal failure)

  Continue pharmacological VTE prophylaxis until the patient no longer has significantly reduced mobility.

Lower Limb Plaster Casts

Consider offering pharmacological VTE prophylaxis to patients with lower limb plaster casts after evaluating the risks and benefits based on clinical discussion with the patient. Offer LMWH (or UFH for patients with renal failure) until lower limb plaster cast removal.

Pregnancy and Up to 6 Weeks Postpartum

Consider offering pharmacological VTE prophylaxis with LMWH (or UFH for patients with renal failure) to women who are pregnant or have given birth within the previous 6 weeks who are admitted to hospital but are not undergoing surgery, and who have one or more of the following risk factors:

• Expected to have significantly reduced mobility for 3 or more days
• Active cancer or cancer treatment
• Age over 35 years
• Critical care admission
• Dehydration
• Excess blood loss or blood transfusion
• Known thrombophilias
• Obesity (pre-pregnancy or early pregnancy BMI 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 a first-degree relative with a history of VTE
• Pregnancy-related risk factor (such as ovarian hyperstimulation, hyperemesis gravidarum, multiple pregnancy or pre-eclampsia)
• Varicose veins with phlebitis

Consider offering combined VTE prophylaxis with mechanical methods and LMWH (or UFH for patients with renal failure) to women who are pregnant or have given birth within the previous 6 weeks who are undergoing surgery, including caesarean section.

Offer mechanical and/or pharmacological VTE prophylaxis to women who are pregnant or have given birth within the previous 6 weeks only after assessing the risks and benefits and discussing these with the woman and with healthcare professionals who have knowledge of the proposed method of VTE prophylaxis during pregnancy and postpartum. Plan when to start and stop pharmacological VTE prophylaxis to minimise the risk of bleeding.

Critical Care

Assess all patients on admission to the critical care unit for their risks of VTE and bleeding (see Box 2). Reassess patients' risks of VTE and bleeding daily and more frequently if their clinical condition is changing rapidly.

Offer VTE prophylaxis to patients admitted to the critical care unit according to the reason for admission, taking into account:

• Any planned interventions
• The use of other therapies that may increase the risk of complications

Review decisions about VTE prophylaxis for patients in critical care daily and more frequently if their clinical condition is changing rapidly. Take into account the known views of the patient, comments from their family and/or carers and the multidisciplinary team.

Patients Already Having Antiplatelet Agents or Anticoagulation on Admission or Needing Them for Treatment

Consider offering additional mechanical or pharmacological VTE prophylaxis to patients who are having antiplatelet agents to treat other conditions and who are assessed to be at increased risk of VTE. Take into account the risk of bleeding (see Box 2) and of comorbidities such as arterial thrombosis.

• If the risk of VTE outweighs the risk of bleeding, consider offering pharmacological VTE prophylaxis according to the reason for admission.
• If the risk of bleeding outweighs the risk of VTE, offer mechanical VTE prophylaxis.

Do not offer additional pharmacological or mechanical VTE prophylaxis to patients who are taking vitamin K antagonists and who are within their therapeutic range, providing anticoagulant therapy is continued.

Do not offer additional pharmacological or mechanical VTE prophylaxis to patients who are having full anticoagulant therapy (for example, fondaparinux sodium, LMWH or UFH).

Patient Information and Planning for Discharge

Patient Information

Be aware that heparins are of animal origin and this may be of concern to some patients*. For patients who have concerns about using animal products, consider offering synthetic alternatives based on clinical judgement and after discussing their suitability, advantages and disadvantages with the patient.

*See 'Religion or belief: a practical guide for the NHS', available from www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuidance/DH_093133 .

Before starting VTE prophylaxis, offer patients and/or their families or carers 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 (for example, anti-embolism stockings, foot impulse or intermittent pneumatic compression devices)

How patients can reduce their risk of VTE (such as keeping well hydrated and, if possible, exercising and becoming more mobile).

Planning for Discharge

As part of the discharge plan, offer patients and/or their families or carers 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 using VTE prophylaxis correctly and continuing treatment for the recommended duration (if discharged with prophylaxis)
• The signs and symptoms of adverse events related to VTE prophylaxis (if discharged with prophylaxis)
• The importance of seeking help and who to contact if they have any problems using the prophylaxis (if discharged with prophylaxis)
• The importance of seeking medical help and who to contact if deep vein thrombosis, pulmonary embolism or other adverse events are suspected

Ensure that patients who are discharged with anti-embolism stockings:

• Understand the benefits of wearing them
• Understand the need for daily hygiene removal
• Are able to remove and replace them, or have someone available who will be able to do this for them
• Know what to look for, such as skin marking, blistering or discolouration, particularly over the heels and bony prominences
• Know who to contact if there is a problem

Ensure that patients who are discharged with pharmacological and/or mechanical VTE prophylaxis are able to use it correctly, or have arrangements made for someone to be available who will be able to help them.

Notify the patient's general practitioner if the patient has been discharged with pharmacological and/or mechanical VTE prophylaxis to be used at home.

The following algorithms are provided in the quick reference guide (see the "Availability of Companion Documents" field):

• Care pathway
• Medical patients
• Patients in palliative care
• Non-orthopaedic surgery
• Orthopaedic surgery
• Major trauma or spinal injury
• Lower limb plaster casts
• Critical care
• Pregnancy and up to 6 weeks postpartum

The type of evidence supporting the recommendations is not specifically stated.

Appropriate use of evidence-based interventions to reduce the risk of venous thromboembolism (VTE)

Adverse events related to venous thromboembolism (VTE) prophylaxis:

• Poorly fitted stockings or those of an incorrect shape and size have the potential to cause a tourniquet effect on the proximal part of the limb where the stocking is applied. This can result in ischaemia and an increased risk of thrombosis development.
• The risk of developing a haematoma as a result of regional anaesthetic technique is a concern.
• There is a risk of bleeding (haemorrhagic transformation of stroke or bleeding into another site).

Anti-embolism stockings are contraindicated in patients with peripheral arterial disease, arteriosclerosis, severe peripheral neuropathy, massive leg oedema or pulmonary oedema, oedema secondary to congestive cardiac failure, local skin/soft tissue diseases such as recent skin graft or dermatitis, extreme deformity of the leg, gangrenous limb and Doppler pressure index <0.8, or cellulitis.

The Healthcare Commission assesses the performance of National health Service (NHS) organizations in meeting core and developmental standards set by the Department of Health in 'Standards for better health' (available from www.dh.gov.uk ). Implementation of clinical guidelines forms part of the developmental standard D2. Core standard C5 says that national agreed guidance should be taken into account when NHS organizations are planning and delivering care.

The National Institute for Health and Clinical Excellence (NICE) has developed tools to help organizations implement this guidance. These are available on the NICE Web site (http://guidance.nice.org.uk/CG92 ; see also the "Availability of Companion Documents" field).

Key Priorities for Implementation

Assessing the Risks of Venous Thromboembolism (VTE) and Bleeding

• Assess all patients on admission to identify those who are at increased risk of VTE.
• Regard medical patients as being at increased risk of VTE if they:
  • Have had or are expected to have significantly reduced mobility for 3 days or more or
  • Are expected to have ongoing reduced mobility relative to their normal state and have one or more of the risk factors shown in Box 1 in the full version of the guideline.
• 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 involves the pelvis or lower limb
  • Acute surgical admission with inflammatory or intra-abdominal condition
  • Expected significant reduction in mobility
  • One or more of the risk factors shown in Box 1 in the full version of the guideline
• Assess all patients for risk of bleeding before offering pharmacological VTE prophylaxis*. Do not offer pharmacological VTE prophylaxis to patients with any of the risk factors for bleeding shown in Box 2 in the full version of the guideline, unless the risk of VTE outweighs the risk of bleeding.
• Reassess patients' risks of bleeding and VTE within 24 hours of admission and whenever the clinical situation changes, to:
  • Ensure that the methods of VTE prophylaxis being used are suitable
  • Ensure that VTE prophylaxis is being used correctly
  • Identify adverse events resulting from VTE prophylaxis

Reducing the Risk of VTE

• Encourage patients to mobilise as soon as possible.
• Offer pharmacological VTE prophylaxis to general medical patients assessed to be at increased risk of VTE. Choose any one of:
  • Fondaparinux sodium
  • Low molecular weight heparin (LMWH)**
  • Unfractionated heparin (UFH) (for patients with renal failure)
• Start pharmacological VTE prophylaxis as soon as possible after risk assessment has been completed. Continue until the patient is no longer at increased risk of VTE.

Patient Information and Planning for Discharge

Before starting VTE prophylaxis, offer patients and/or their families or carers 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 (for example, anti-embolism stockings, foot impulse or intermittent pneumatic compression devices)
• How patients can reduce their risk of VTE (such as keeping well hydrated and, if possible, exercising and becoming more mobile).
• As part of the discharge plan, offer patients and/or their families or carers 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 using VTE prophylaxis correctly and continuing treatment for the recommended duration (if discharged with prophylaxis)
  • The signs and symptoms of adverse events related to VTE prophylaxis (if discharged with prophylaxis)
  • The importance of seeking help and who to contact if they have any problems 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.

*Prescribers should consult the summary of product characteristics for the pharmacological VTE prophylaxis being used or planned for further details.

**At the time of publication (January 2010) some types of LMWH do not have UK marketing authorisation for VTE prophylaxis in medical patients. Prescribers should consult the summary of product characteristics for the individual LMWH. Informed consent for off-label use should be obtained and documented.

Not applicable: The guideline was not adapted from another source.

National Institute for Health and Clinical Excellence (NICE)

Guideline Development Group

Guideline Development Group Members: Professor Tom Treasure (Chair), Honorary Professor and Honorary Consultant, Clinical Operational Research Unit, University College London; Mrs Kim Carter, DVT Nurse Specialist, Portsmouth Hospitals NHS Trust, Queen Alexandra Hospital, Portsmouth; Dr Nandan Gautam, Consultant in General Medicine and Critical Care, Selly Oak Hospital, Birmingham; Professor Aroon Hingorani, Professor of Genetic Epidemiology, British Heart Foundation Senior Research Fellow, and Honorary Consultant Physician, University College London Hospitals NHS Foundation Trust; Dr Rodney Hughes, Consultant Respiratory Physician, Northern General Hospital, Sheffield; Professor Beverley Hunt, Consultant in Departments of Haematology, Pathology and Rheumatology, Guy's and St. Thomas' Foundation Trust, London; Dr Nigel Langford, Consultant Physician and Clinical Pharmacologist, City Hospital, Birmingham; Mr Paul Mainwaring, Patient representative, Bury; Mr Donald McBride, Consultant Orthopaedic Surgeon, University Hospital North Staffordshire; Gordon McPherson, Patient representative, Renfrewshire; Dr Simon Noble, Clinical Senior Lecturer and Honorary Consultant in Palliative Medicine, Royal Gwent Hospital, Newport; Professor Gerard Stansby, Professor of Vascular Surgery, Freeman Hospital, Newcastle upon Tyne; Dr Peter Walton, Patient representative, Cheshire; Ms Annie Young, Nurse Director, 3 Counties Cancer Network, Gloucestershire, Herefordshire and South Worcestershire

Members of the Guideline Development Group declared any interests in accordance with the National Institute for Health and Clinical Excellence (NICE) technical manual. A register is given in Appendix B of the full version of the original guideline (see "Availability of Companion Documents" field).

This is the current release of the guideline.

This guideline updates a previous version: National Collaborating Centre for Acute Care. Venous thromboembolism. Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in inpatients undergoing surgery. London (UK): National Institute for Health and Clinical Excellence (NICE); 2007. 163 p. [587 references]

Electronic copies: Available in Portable Document Format (PDF) format from the National Institute for Health and Clinical Excellence (NICE) Web site .

The following are available:

• Venous thromboembolism. Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in inpatients admitted to hospital. Quick reference guide. London (UK): National Institute for Health and Clinical Excellence (NICE); 2010 Jan. 26 p. (Clinical guideline; no. CG92). Electronic copies: Available in Portable Document Format (PDF) from the National Institute for Health and Clinical Excellence (NICE) Web site .
• Venous thromboembolism: reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients admitted to hospital. Full guideline. London (UK): National Institute for Health and Clinical Excellence (NICE); 2010 Jan. 509 p. (Clinical guideline; no. 92). Electronic copies: Available in PDF from the NICE Web site .
• Venous thromboembolism: reducing the risk. Audit support. Implementing NICE guidance. London (UK): National Institute for Health and Clinical Excellence (NICE); 2010 Jan. 26 p. (Clinical guideline; no. CG92). Electronic copies: Available from the NICE Web site .
• Venous thromboembolism: reducing the risk. Costing report. Implementing NICE guidance. London (UK): National Institute for Health and Clinical Excellence (NICE); 2010 Jan. 30 p. (Clinical guideline; no. CG92). Electronic copies: Available in PDF from the NICE Web site .
• Venous thromboembolism: reducing the risk. Costing template. Implementing NICE guidance. London (UK): National Institute for Health and Clinical Excellence (NICE); 2010 Jan. (Clinical guideline; no. CG92). Electronic copies: Available from the NICE Web site .
• Venous thromboembolism: reducing the risk. Slide set. Implementing NICE guidance. London (UK): National Institute for Health and Clinical Excellence (NICE); 2010 Jan. 25 p. (Clinical guideline; no. CG92). Electronic copies: Available from the NICE Web site .
• Venous thromboembolism: reducing the risk. Baseline assessment tool. Implementing NICE guidance. London (UK): National Institute for Health and Clinical Excellence (NICE); 2010 Dec. (Clinical guideline; no. CG92). Electronic copies: Available from the NICE Web site .
• Venous thromboembolism: reducing the risk. Guide to resources. Implementing NICE guidance. London (UK): National Institute for Health and Clinical Excellence (NICE); 2010 Jan. 18 p. (Clinical guideline; no. CG92). Electronic copies: Available from the NICE Web site .
• Venous thromboembolism: reducing the risk. Online education tool. London (UK): National Institute for Health and Clinical Excellence (NICE); 2010 Sep. (Clinical guideline; no. CG92). Electronic copies: Available from the NICE Web site .

The following is available:

• Venous thromboembolism. Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in inpatients admitted to hospital. Understanding NICE guidance. Information for people who use NHS services. London (UK): National Institute for Health and Clinical Excellence (NICE); 2010 Jan. 16 p. (Clinical guideline; no. CG92). Electronic copies: Available in Portable Document Format (PDF) from the National Institute for Health and Clinical Excellence (NICE) Web site . Also available in Welsh from the NICE Web site .

Please note: This patient information is intended to provide health professionals with information to share with their patients to help them better understand their health and their diagnosed disorders. By providing access to this patient information, it is not the intention of NGC to provide specific medical advice for particular patients. Rather we urge patients and their representatives to review this material and then to consult with a licensed health professional for evaluation of treatment options suitable for them as well as for diagnosis and answers to their personal medical questions. This patient information has been derived and prepared from a guideline for health care professionals included on NGC by the authors or publishers of that original guideline. The patient information is not reviewed by NGC to establish whether or not it accurately reflects the original guideline's content.

This summary was completed by ECRI Institute on November 13, 2009. This summary was updated by ECRI Institute on January 13, 2010.

The National Institute for Health and Clinical Excellence (NICE) has granted the National Guideline Clearinghouse (NGC) permission to include summaries of their clinical guidelines with the intention of disseminating and facilitating the implementation of that guidance. NICE has not yet verified this content to confirm that it accurately reflects that original NICE guidance and therefore no guarantees are given by NICE in this regard. All NICE clinical guidelines are prepared in relation to the National Health Service in England and Wales. NICE has not been involved in the development or adaptation of NICE guidance for use in any other country. The full versions of all NICE guidance can be found at www.nice.org.uk .

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.