VTE prophylaxis

Last reviewed: February 2019

Last updated: July 2018

Summary

Thromboprophylaxis is the most important patient safety strategy in patients admitted to hospital. Pulmonary embolism remains the leading cause of preventable in-hospital death.

The risk of venous thrombosis in patients admitted to hospital depends on medical versus surgical admission and, among surgical patients, the type of surgery.

Evaluating venous thromboembolic risk factors within these patient groups helps further stratify the thrombotic risk.

Bleeding risk and possible contraindication to anti-thrombotic agents must be assessed before instituting thromboprophylaxis.

Although national and international thromboprophylaxis guidelines have repeatedly recommended thromboprophylaxis of patients admitted to hospital, only 40% to 50% of medical patients and 60% to 75% of surgical patients receive adequate thromboprophylaxis.

Computer-based decision systems and pre-printed orders are most effective in optimising physician adherence to thromboprophylaxis guidelines. Periodic audits by pharmacists or other health professionals reinforce the consistent use of venous thromboembolism prophylaxis.

Definition

Venous thromboembolism (VTE) prophylaxis consists of pharmacological and non-pharmacological measures to diminish the risk of deep vein thrombosis (DVT) and pulmonary embolism (PE).

DVT of the leg is the development of a blood clot in one of the major deep veins in the leg or thigh, which leads to impaired venous blood flow, usually causing leg swelling and pain.

PE is a consequence of thrombus formation in distal veins, most commonly those of the deep venous system of the lower extremities. Thrombus formation in the venous system occurs as a result of venous stasis, trauma, and hypercoagulability. About 51% of deep venous thrombi will embolise to the pulmonary vasculature, resulting in a PE. [1]

History and exam

Key diagnostic factors

previous VTE, thrombophilia, malignancy, postoperative setting, trauma, and indwelling central catheter
chronic medical conditions, paresis, increasing age, obesity, oestrogen-containing contraceptive pills and HRT, varicose veins, pregnancy and up to 6 week postnatal, first-degree relative with a history of VTE, extended travel, and admission to intensive care

Full details

Risk factors

previous VTE (deep vein thrombosis [DVT] and/or pulmonary embolism [PE])
thrombophilia
malignancy
postoperative setting
trauma
indwelling central catheter (upper or lower extremity)
immobility
myeloproliferative diseases
congestive heart failure
chronic obstructive pulmonary disease
inflammatory bowel disease
neurological disease with extremity paresis
increasing age
obesity
oestrogen-containing contraceptive pills, HRT, and androgen deprivation therapy
history of varicose veins
pregnancy/postnatal
extended travel
lower leg immobility
first-degree relative with a history of VTE
admission to intensive care

Full details

Diagnostic investigations

1st investigations to order

FBC
serum creatinine
INR
PTT

Full details

Investigations to consider

serum antiplatelet factor 4 antibodies

Full details

Treatment algorithm

INITIAL

all at-risk patients

ACUTE

trauma patients

surgical patients

medical patients

Contributors

Authors VIEW ALL 

Nathalie Routhier, MD, MSc, FRCPC

Attending Physician

Assistant Professor

University of Montreal

Montreal

Canada

Disclosures

NR declares that she has no competing interests.

Vicky Tagalakis, MD, FRCPC, MSC

Associate Professor

General Internal Medicine Program Director

McGill University Division of Internal Medicine

Centre for Clinical Epidemiology of the Lady Davis Institute for Medical Research

Jewish General Hospital

Montreal

Canada

Disclosures

VT declares that she has received an investigator-initiated grant from Sanofi-Aventis. She has also received consultancy fees from Bristol-Myers Squibb, Leo Pharma, Pfizer, Sanofi-Aventis, and Daiichi Sanyo. VT is an author of a reference cited in this monograph.

Adi J. Klil-Drori, MD, MSc

Postdoctoral Fellow

McGill University

Centre for Clinical Epidemiology of the Lady Davis Institute for Medical Research

Jewish General Hospital

Montreal

Canada

Disclosures

AJKD declares that he has no competing interests.

Acknowledgements

Dr Nathalie Routhier, Dr Vicky Tagalakis, and Dr Adi J. Klil-Drori would like to gratefully acknowledge Dr Vincent Bouchard-Dechêne, a previous contributor to this monograph. VBD declares that he has no competing interests.

Peer reviewers VIEW ALL 

Andrew Parfitt, MBBS, FFAEM

Clinical Director

Acute Medicine

Associate Medical Director

Consultant Emergency Medicine

Guy's and St Thomas' NHS Foundation Trust

Clinical Lead and Consultant

Accident Emergency Medicine

St Thomas' Hospital

London

Disclosures

AP declares that he has no competing interests.

Sudeep Shivakumar, MD

Hematologist

Thrombosis Fellow

University of Ottawa

Ottawa Health Research Institute

Ottawa

Canada

Disclosures

SS declares that he has no competing interests.

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VTE prophylaxis

Summary

Definition

History and exam

Key diagnostic factors

Risk factors

Diagnostic investigations

1st investigations to order

Investigations to consider

Treatment algorithm

all at-risk patients

trauma patients

surgical patients

medical patients

Contributors

Authors VIEW ALL 

Nathalie Routhier, MD, MSc, FRCPC

Disclosures

Vicky Tagalakis, MD, FRCPC, MSC

Disclosures

Adi J. Klil-Drori, MD, MSc

Disclosures

Acknowledgements

Peer reviewers VIEW ALL 

Andrew Parfitt, MBBS, FFAEM

Disclosures

Sudeep Shivakumar, MD

Disclosures

Guidelines

Patient leaflets

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