View source for Deep vein thrombosis prevention

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| [[Venous thromboembolism prevention resident survival guide|'''Resident'''<br>'''Survival'''<br>'''Guide''']]
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{{Deep vein thrombosis}}
'''Editor(s)-In-Chief:''' {{ATI}}, [[C. Michael Gibson, M.S., M.D.]] [mailto:charlesmichaelgibson@gmail.com]; {{AE}} {{CZ}}; [[User:Kashish Goel|Kashish Goel, M.D.]]; [[User:Justine Cadet|Justine Cadet]]; {{Rim}}

'''For information on randomized trials which compared the efficacy and safety of antithrombins and anticoagulants in the prevention of deep vein thrombosis, click [[Deep vein thrombosis landmark trials in prevention|here]]'''

{{SK}} DVT prophylaxis, VTE prophylaxis

==Overview==
Venous thromboembolism (VTE) consists of deep vein thrombosis (DVT), pulmonary embolism (PE), or both. VTE is a disease associated with morbidity and mortality; therefore, VTE prophylaxis is indicated among specific categories of patients at elevated risk for VTE.  [[VTE]] prophylaxis can be either pharmacological through the administration of medications such as [[low molecular weight heparin]] (LMWH) or [[fondaparinux]] among others, or mechanical through [[intermittent pneumatic compression]] or elastic stockings.  The decision to administer VTE prophylaxis, the duration of the prophylaxis treatment and the choice of the modality depend on the reason for hospitalization such as medical illness, non orthopedic surgery or orthopedic surgery, as well as on the estimated risk of subsequent [[VTE]] and the estimated risk of [[bleeding]].

==VTE Prevention==
This chapter discusses VTE prophylaxis in the following categories of subjects:
* [[Deep vein thrombosis prevention#VTE Prevention in Non Surgical Patients|Non surgical patients]]
** [[Deep vein thrombosis prevention#Assessment of Risks|Assessment of Risks]]
** [[Deep vein thrombosis prevention#Hospitalized Acutely Ill Medical Patients|Hospitalized Acutely ill Medical Patients]]
** [[Deep vein thrombosis prevention#Critically Ill Hospitalized Patients|Critically-ill hospitalized patients]]
** [[Deep vein thrombosis prevention#Cancer in Outpatient|Cancer in outpatient]]
** [[Deep vein thrombosis prevention#Chronically Immobilized Patients|Chronically immobilized patients]]
** [[Deep vein thrombosis prevention#Long Travel|Long travel]]
** [[Deep vein thrombosis prevention#Asymptomatic Thrombophilia|Asymptomatic thrombophilia]]
** [[Deep vein thrombosis prevention#Non Hospitalized Subjects|Non-hospitalized subjects]]
* [[Deep vein thrombosis prevention#VTE Prevention in Non Orthopedic Surgical Patients|Non orthopedic surgical patients]]
** [[Deep vein thrombosis prevention#General and Abdominal-Pelvic Surgeries|General and abdominal pelvic surgeries]]
** [[Deep vein thrombosis prevention#Cardiac Surgery|Cardiac surgery]]
** [[Deep vein thrombosis prevention#Thoracic Surgery|Thoracic surgery]]
** [[Deep vein thrombosis prevention#Craniotomy|Craniotomy]]
** [[Deep vein thrombosis prevention#Spinal Surgery|Spinal surgery]]
** [[Deep vein thrombosis prevention#Trauma|Trauma]]
* [[Deep vein thrombosis prevention#Orthopedic Surgery|Orthopedic surgery]]
** [[Deep vein thrombosis prevention#Major Orthopedic Surgery|Major orthopedic surgery]]
** [[Deep vein thrombosis prevention#Isolated Lower Leg Injury|Isolated lower leg injury]]
** [[Deep vein thrombosis prevention#Knee Arthroscopy|Knee arthroscopy]]

==VTE Prevention in Non Surgical Patients==
===Assessment of Risks===
====Assessment of the Risk of VTE====
=====Padua Prediction Score for VTE=====
Shown below is a table depicting Padua predictive score for VTE among hospitalized medical patients.  The interpretation of the score is as follows:
* '''Score≥ 4: High risk for VTE'''
* '''Score< 4: Low risk for VTE'''<ref name="pmid20738765">{{cite journal| author=Barbar S, Noventa F, Rossetto V, Ferrari A, Brandolin B, Perlati M et al.| title=A risk assessment model for the identification of hospitalized medical patients at risk for venous thromboembolism: the Padua Prediction Score. | journal=J Thromb Haemost | year= 2010 | volume= 8 | issue= 11 | pages= 2450-7 | pmid=20738765 | doi=10.1111/j.1538-7836.2010.04044.x | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20738765  }} </ref>

{| style="cellpadding=0; cellspacing= 0; width: 600px;"
|-
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Variable'''||style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Score'''
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left | Active [[cancer]]|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left | 3
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Previous [[VTE]]|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |3
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Decreased mobility||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |3
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Thrombophilia]]|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |3
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Previous trauma or surgery within that last month||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Age≥ 70||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Heart failure|Heart]] and/or [[respiratory failure]]||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Ischemic stroke]] or [[acute myocardial infarction]]||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Acute rheumatologic disorder and/or acute infection||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Obesity]]||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Hormonal therapy]]||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|}

=====IMPROVE Predictive Score for VTE=====
======Calculation of the IMPROVE Predictive Score======
{| style="cellpadding=0; cellspacing= 0; width: 600px;"
|-
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Variable'''||style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Score'''<ref name="pmid21436241">{{cite journal| author=Spyropoulos AC, Anderson FA, Fitzgerald G, Decousus H, Pini M, Chong BH et al.| title=Predictive and associative models to identify hospitalized medical patients at risk for VTE. | journal=Chest | year= 2011 | volume= 140 | issue= 3 | pages= 706-14 | pmid=21436241 | doi=10.1378/chest.10-1944 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21436241  }} </ref>
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left | Prior episode of [[VTE]]|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left | 3
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Thrombophilia]]|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |3
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Malignancy]]||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Age more than 60 years|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|}

======Interpretation of the IMPROVE Predictive Score======
{| style="cellpadding=0; cellspacing= 0; width: 600px;"
|-
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Score'''||style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Predicted VTE risk through 3 months'''<ref name="pmid21436241">{{cite journal| author=Spyropoulos AC, Anderson FA, Fitzgerald G, Decousus H, Pini M, Chong BH et al.| title=Predictive and associative models to identify hospitalized medical patients at risk for VTE. | journal=Chest | year= 2011 | volume= 140 | issue= 3 | pages= 706-14 | pmid=21436241 | doi=10.1378/chest.10-1944 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21436241  }} </ref>
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left | 0|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |0.5%
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1.0%
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1.7%
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |3|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |3.1%
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |4|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |5.4%
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |5-8|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |11%
|}

=====IMPROVE Associative Score for VTE=====
IMPROVE associative risk score assesses the risk of VTE among hospitalized medical patients. While the IMPROVE predictive score includes 4 independent risk factors for VTE which are present at admission, IMPROVE associative score includes 7 variables present either at admission or during hospitalization; however the timing of the presence of some of the factors compared to the onset of VTE is not available.<ref name="pmid21436241">{{cite journal| author=Spyropoulos AC, Anderson FA, Fitzgerald G, Decousus H, Pini M, Chong BH et al.| title=Predictive and associative models to identify hospitalized medical patients at risk for VTE. | journal=Chest | year= 2011 | volume= 140 | issue= 3 | pages= 706-14 | pmid=21436241 | doi=10.1378/chest.10-1944 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21436241  }} </ref>  Approximately, 2/3 of medically-ill hospitalized patients are considered at low risk when stratified by IMPROVE-score.<ref name="pmid24990708">{{cite journal| author=Mahan CE, Liu Y, Turpie AG, Vu JT, Heddle N, Cook RJ et al.| title=External validation of a risk assessment model for venous thromboembolism in the hospitalised acutely-ill medical patient (VTE-VALOURR). | journal=Thromb Haemost | year= 2014 | volume= 112 | issue= 4 | pages= 692-9 | pmid=24990708 | doi=10.1160/TH14-03-0239 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24990708  }} </ref>

======Calculation of the IMPROVE Associative Score======
{| style="cellpadding=0; cellspacing= 0; width: 600px;"
|-
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Variable'''||style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Score'''<ref name="pmid21436241">{{cite journal| author=Spyropoulos AC, Anderson FA, Fitzgerald G, Decousus H, Pini M, Chong BH et al.| title=Predictive and associative models to identify hospitalized medical patients at risk for VTE. | journal=Chest | year= 2011 | volume= 140 | issue= 3 | pages= 706-14 | pmid=21436241 | doi=10.1378/chest.10-1944 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21436241  }} </ref>
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left | Prior episode of [[VTE]]|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left | 3
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Thrombophilia]]|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Paralysis of the lower extremity during the hospitalization||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Current [[malignancy]]|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Immobilization for at least 7 days|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[ICU]] or [[CCU]] admission|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Age more than 60 years|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|}

======Interpretation of the IMPROVE Associative Score======
{| style="cellpadding=0; cellspacing= 0; width: 600px;"
|-
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Score'''||style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Risk''' ||style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center  colspan="2" | '''Predicted VTE risk through 3 months<br/>(derivation study)'''<ref name="pmid21436241">{{cite journal| author=Spyropoulos AC, Anderson FA, Fitzgerald G, Decousus H, Pini M, Chong BH et al.| title=Predictive and associative models to identify hospitalized medical patients at risk for VTE. | journal=Chest | year= 2011 | volume= 140 | issue= 3 | pages= 706-14 | pmid=21436241 | doi=10.1378/chest.10-1944 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21436241  }} </ref> ||style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center colspan="2"| '''Predicted VTE risk through 3 months<br/>(validation study - VTE-VALOURR)'''<ref name="pmid24990708">{{cite journal| author=Mahan CE, Liu Y, Turpie AG, Vu JT, Heddle N, Cook RJ et al.| title=External validation of a risk assessment model for venous thromboembolism in the hospitalised acutely-ill medical patient (VTE-VALOURR). | journal=Thromb Haemost | year= 2014 | volume= 112 | issue= 4 | pages= 692-9 | pmid=24990708 | doi=10.1160/TH14-03-0239 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24990708  }} </ref>
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left | 0|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center rowspan="2"|Low ||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center |0.4%||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center rowspan="2"|0.5%|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center |0.7%||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center rowspan="2"|0.20%
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center |0.6%|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center |0.8%
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center rowspan="2"|Moderate||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center |1.0%|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center rowspan="2"|1.3%|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center|1.4%||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center rowspan="2"|1.0%
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |3|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center |1.7%|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center |1.9%
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |4|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center rowspan="2"|High|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center |2.9%||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center rowspan="2"|4.7%||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center |4.2%||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center rowspan="2"|4.2%
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |5-10|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center |7.2%|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=center |7% to 100%<br/>(exact rate not calculable)
|}

====Assessment of the Risk of Bleeding====
=====IMPROVE Bleeding Risk Score=====
Shown below is a table depicting the IMPROVE risk score for bleeding among hospitalized medical patients.  The scores can be interpreted as such:<ref name="pmid20453069">{{cite journal| author=Decousus H, Tapson VF, Bergmann JF, Chong BH, Froehlich JB, Kakkar AK et al.| title=Factors at admission associated with bleeding risk in medical patients: findings from the IMPROVE investigators. | journal=Chest | year= 2011 | volume= 139 | issue= 1 | pages= 69-79 | pmid=20453069 | doi=10.1378/chest.09-3081 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20453069  }} </ref>
* '''Score ≥7: Elevated risk of bleeding'''
* '''Score <7: Not elevated risk of bleeding'''

{| style="cellpadding=0; cellspacing= 0; width: 600px;"
|-
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Variable'''||style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align=center | '''Score'''
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Active [[gastric ulcer|gastric]] or [[duodenal ulcer]] || style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |4.5
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Prior [[bleeding]] within the last 3 months|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |4
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Thrombocytopenia]] (<50x10<sup>9</sup>/L)||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |4
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Age ≥ 85 years||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |3.5
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Liver failure]] ([[INR]]>1.5)||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2.5
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Kidney failure|Severe kidney failure]] ([[GFR]]< 30 mL/min/m<sup>2</sup>)||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2.5
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Admission to [[ICU]] or [[CCU]]||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2.5
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Central venous catheter]]||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Rheumatic disease||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Active [[malignancy]]||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |2
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Age: 40-84 years|| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1.5
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |Male||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|-
| style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |[[Kidney failure|Moderate kidney failure]] ([[GFR]]: 30-59 mL/min/m<sup>2</sup>)||style="font-size: 90%; padding: 0 5px; background: #DCDCDC" align=left |1
|}

===Hospitalized Acutely Ill Medical Patients===
Shown below is an algorithm the indications and choices of [[VTE]] prophylaxis among acutely ill patients.  If VTE prophylaxis is recommended, it should be administered for the period of immobilization or hospital stay.  Do not extend the duration of the prophylaxis after the period of immobilization or hospital stay.  If pharmacological [[anticoagulation]] is needed, the choice of the drug should be guided by the patient preference, readiness for compliance and the practicality of the administration of frequent doses.<ref name="pmid22315261">{{cite journal| author=Kahn SR, Lim W, Dunn AS, Cushman M, Dentali F, Akl EA et al.| title=Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e195S-226S | pmid=22315261 | doi=10.1378/chest.11-2296 | pmc=PMC3278052 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315261  }} </ref>

<span style="font-size:85%"> '''Abbreviations:''' '''BID:''' bis in die (twice daily); '''LDUH:''' Low dose [[unfractionated heparin]]; '''LMWH:''' [[Low molecular weight heparin]]; '''TID:''' ter in die (three times daily); '''VTE:''' Venous thromboembolism </span>

{{Family tree/start}}
{{familytree  | | | | | | A01 | | | A01= '''[[Deep vein thrombosis prevention#Assessment of the Risk of VTE|What is the risk of thrombosis in the acutely ill patient?]]'''}}
{{familytree  | | | | |,|-|^|-|.| | | }}
{{familytree  | | | | B01 | | B02 | B01= High| B02= Low}}
{{familytree  | | | | |!| | | |!| | }}
{{familytree  | | | | C01 | | C02 | C01= '''[[Deep vein thrombosis prevention#IMPROVE Bleeding Risk Score|Is the patient bleeding or at high risk of bleeding?]]'''| C02= No VTE prophylaxis }}
{{familytree  | | |,|-|^|-|.| | }}
{{familytree  | | D01 | | D02 | D01= Yes| D02= No}}
{{familytree  | | |!| | | |!| | }}
{{familytree  | | E01 | | E02 | E01= '''Mechanical VTE prophylaxis''' <br><div style="float: left; text-align: left; padding:1em;"> '''''For the period of immobilization or hospital stay only'''''<br> ❑ [[Graduated compression stocking]] <br> ❑ [[Intermittent pneumatic compression]]</div>| E02= '''Pharmacological VTE prophylaxis'''<br> <div style="float: left; text-align: left; padding:1em;">'''''For extended period (beyond hospital stay)'''''<ref name="pmid27232649">{{cite journal |vauthors=Cohen AT, Harrington RA, Goldhaber SZ, Hull RD, Wiens BL, Gold A, Hernandez AF, Gibson CM |title=Extended Thromboprophylaxis with Betrixaban in Acutely Ill Medical Patients |journal=N. Engl. J. Med. |volume=375 |issue=6 |pages=534–44 |year=2016 |pmid=27232649 |doi=10.1056/NEJMoa1601747 |url=}}</ref><ref name="pmid28267480">{{cite journal |vauthors=Gibson CM, Halaby R, Korjian S, Daaboul Y, Arbetter DF, Yee MK, Goldhaber SZ, Hull R, Hernandez AF, Lu SP, Bandman O, Leeds JM, Gold A, Harrington RA, Cohen AT |title=The safety and efficacy of full- versus reduced-dose betrixaban in the Acute Medically Ill VTE (Venous Thromboembolism) Prevention With Extended-Duration Betrixaban (APEX) trial |journal=Am. Heart J. |volume=185 |issue= |pages=93–100 |year=2017 |pmid=28267480 |doi=10.1016/j.ahj.2016.12.004 |url=}}</ref><ref name="pmid22190427">{{cite journal |vauthors=Amin AN, Varker H, Princic N, Lin J, Thompson S, Johnston S |title=Duration of venous thromboembolism risk across a continuum in medically ill hospitalized patients |journal=J Hosp Med |volume=7 |issue=3 |pages=231–8 |year=2012 |pmid=22190427 |doi=10.1002/jhm.1002 |url=}}</ref><br> ❑ [[Betrixaban]] 160 mg PO Day 1 then 80 mg OD for 35 to 42 days <br>'''''For the period of immobilization or hospital stay only'''''<br> ❑ [[LMWH]] <br> ❑ [[LDUH]], BID <br> ❑ [[LDUH]], TID <br> ❑ [[Fondaparinux]] </div>}}
{{familytree  | | |!| | | | | | }}
{{familytree  | | F01 | | | | | F01= '''Did the bleeding or [[bleeding]] risk subside'''<br> AND <br>'''the patient is still at increased risk of [[thrombosis]]?'''}}
{{familytree  | |,|^|-|-|-|.| | }}
{{familytree  | G01 | | G02 | G01= Yes| G02= No}}
{{familytree  | |!| | | |!| | }}
{{familytree  | H01 | | H02 | H01= ❑ Substitute mechanical prophylaxis by pharmacological prophylaxis| H02=❑ Continue mechanical prophylaxis}}
{{Family tree/end}}

====Evidence of Benefit for Hospitalized Acutely Ill Medical Patients====
The [[Cochrane Collaboration]] found in 2014 that [[heparin]]<ref name="pmid24804622">{{cite journal| author=Alikhan R, Bedenis R, Cohen AT| title=Heparin for the prevention of venous thromboembolism in acutely ill medical patients (excluding stroke and myocardial infarction). | journal=Cochrane Database Syst Rev | year= 2014 | volume=  | issue= 5 | pages= CD003747 | pmid=24804622 | doi=10.1002/14651858.CD003747.pub4 | pmc=6491079 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24804622  }} </ref>:
* In 7 trials of 5511 patients, anticoagulation "reduced the odds of deep vein thrombosis (DVT) (OR 0.38; 95% CI 0.29 to 0.51; P < 0.00001)"

The American Society of Hematology 2018 guidelines found<ref name="pmid30482763">{{cite journal| author=Schünemann HJ, Cushman M, Burnett AE, Kahn SR, Beyer-Westendorf J, Spencer FA | display-authors=etal| title=American Society of Hematology 2018 guidelines for management of venous thromboembolism: prophylaxis for hospitalized and nonhospitalized medical patients. | journal=Blood Adv | year= 2018 | volume= 2 | issue= 22 | pages= 3198-3225 | pmid=30482763 | doi=10.1182/bloodadvances.2018022954 | pmc=6258910 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30482763  }} </ref>:
* In 1 trial of 3706 patients<ref name="pmid15289368">{{cite journal| author=Leizorovicz A, Cohen AT, Turpie AG, Olsson CG, Vaitkus PT, Goldhaber SZ | display-authors=etal| title=Randomized, placebo-controlled trial of dalteparin for the prevention of venous thromboembolism in acutely ill medical patients. | journal=Circulation | year= 2004 | volume= 110 | issue= 7 | pages= 874-9 | pmid=15289368 | doi=10.1161/01.CIR.0000138928.83266.24 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15289368  }}  [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=&cmd=prlinks&id=15739987 Review in: ACP J Club. 2005 Mar-Apr;142(2):40] </ref>, anticoagulation reduced the relative risk of proximal DVT ([https://guidelines.gradepro.org/profile/54B577E9-7F80-3A78-B3EA-3850E9A1D432 RR 0.28; 95% CI 0.06 to 1.37])

===Critically Ill Hospitalized Patients===
Shown below is an algorithm depicting the choices for VTE prophylaxis among critically ill patients.  Note that there is not a risk score to estimate the risk subsequent occurrence of [[VTE]] among critically ill patients.  In addition, routine [[compression ultrasound]] screening for [[DVT]] is not recommended among critically ill patients.  Do not extend the duration of the [[VTE]] prophylaxis after the period of immobilization or hospital stay.<ref name="pmid22315261">{{cite journal| author=Kahn SR, Lim W, Dunn AS, Cushman M, Dentali F, Akl EA et al.| title=Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e195S-226S | pmid=22315261 | doi=10.1378/chest.11-2296 | pmc=PMC3278052 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315261  }} </ref>

<span style="font-size:85%"> '''Abbreviations:''' '''LDUH:''' low dose [[unfractionated heparin]]; '''LMWH:''' low molecular weight heparin; '''VTE:''' Venous thromboembolism </span>

{{Family tree/start}}
{{familytree  | | | | A01 | | | A01= '''Is the critically ill patient bleeding or at risk for major bleeding?'''}}
{{familytree  | | |,|-|^|-|.| | }}
{{familytree  | | B01 | | B02 | B01= Yes| B02= No}}
{{familytree  | | |!| | | |!| | }}
{{familytree  | | C01 | | C02 | C01= '''Mechanical VTE prophylaxis''' <br><div style="float: left; text-align: left; padding:1em;">❑ [[Graduated compression stocking]] <br> ❑ [[Intermittent pneumatic compression]]</div>| C02= '''Pharmacological VTE prophylaxis'''<br> <div style="float: left; text-align: left; padding:1em;">'''''For extended period (beyond hospital stay)'''''<ref name="pmid27232649">{{cite journal |vauthors=Cohen AT, Harrington RA, Goldhaber SZ, Hull RD, Wiens BL, Gold A, Hernandez AF, Gibson CM |title=Extended Thromboprophylaxis with Betrixaban in Acutely Ill Medical Patients |journal=N. Engl. J. Med. |volume=375 |issue=6 |pages=534–44 |year=2016 |pmid=27232649 |doi=10.1056/NEJMoa1601747 |url=}}</ref><ref name="pmid28267480">{{cite journal |vauthors=Gibson CM, Halaby R, Korjian S, Daaboul Y, Arbetter DF, Yee MK, Goldhaber SZ, Hull R, Hernandez AF, Lu SP, Bandman O, Leeds JM, Gold A, Harrington RA, Cohen AT |title=The safety and efficacy of full- versus reduced-dose betrixaban in the Acute Medically Ill VTE (Venous Thromboembolism) Prevention With Extended-Duration Betrixaban (APEX) trial |journal=Am. Heart J. |volume=185 |issue= |pages=93–100 |year=2017 |pmid=28267480 |doi=10.1016/j.ahj.2016.12.004 |url=}}</ref><ref name="pmid22190427">{{cite journal |vauthors=Amin AN, Varker H, Princic N, Lin J, Thompson S, Johnston S |title=Duration of venous thromboembolism risk across a continuum in medically ill hospitalized patients |journal=J Hosp Med |volume=7 |issue=3 |pages=231–8 |year=2012 |pmid=22190427 |doi=10.1002/jhm.1002 |url=}}</ref><br><br> ❑ [[Betrixaban]] 160 mg PO Day 1 then 80 mg OD for 35 to 42 days <br>'''''For the period of immobilization or hospital stay only'''''<br> ❑ [[LMWH]] <br> ❑  [[LDUH]]</div>}}
{{familytree  | | |!| | | | | | }}
{{familytree  | | F01 | | | | | F01= '''Did the [[bleeding]] or [[bleeding risk]] subside?'''}}
{{familytree  | |,|^|-|-|-|.| | }}
{{familytree  | G01 | | G02 | G01= Yes| G02= No}}
{{familytree  | |!| | | |!| | }}
{{familytree  | H01 | | H02 | H01= ❑ Substitute mechanical prophylaxis by pharmacological prophylaxis| H02= ❑ Continue mechanical prophylaxis}}
{{Family tree/end}}

===Cancer in Outpatient===
Shown below is an algorithm depicting VTE prophylaxis among [[cancer]] patients.  Note that, cancer patients with indwelling [[central venous catheter]]s do not require VTE prophylaxis with neither [[low molecular weight heparin]], low dose [[unfractionated heparin]] or [[vitamin K antagonist]]s.<ref name="pmid22315261">{{cite journal| author=Kahn SR, Lim W, Dunn AS, Cushman M, Dentali F, Akl EA et al.| title=Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e195S-226S | pmid=22315261 | doi=10.1378/chest.11-2296 | pmc=PMC3278052 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315261  }} </ref>

<span style="font-size:85%"> '''Abbreviations:''' '''LDUH:''' low dose [[unfractionated heparin]]; '''LMWH:''' low molecular weight heparin; '''VTE:''' Venous thromboembolism </span>

{{Family tree/start}}
{{familytree  | | | A01 | | | A01= <div style="float: left; text-align: left; padding:1em;">❑ '''Does the patient have a [[solid tumor]]''' <br> '''AND''' <br> ❑ '''Additional risk factors for [[VTE]]?'''
:❑ Previous [[VTE]]
:❑ [[Hormonal therapy]]
:❑ Immobilization
:❑ [[Angiogenesis inhibitor]]s
:❑ [[Thalidomide]]
:❑ [[Lenalidomide]] </div>}}
{{familytree  | |,|-|^|-|.| | }}
{{familytree  | B01 | | B02 | | B01= Yes| B02= No}}
{{familytree  | |!| | | |!| | }}
{{familytree  | C01 | | C02 | | C01= '''Pharmacological VTE prophylaxis''' <br> <div style="float: left; text-align: left; padding:1em;">❑ [[LMWH]]<br>❑ [[LDUH]] </div>| C02= ❑ No VTE prophylaxis}}
{{Family tree/end}}

===Chronically Immobilized Patients===
No VTE prophylaxis is recommended among subjects who are chronically immobilized either at home or at a nursing home.<ref name="pmid22315261">{{cite journal| author=Kahn SR, Lim W, Dunn AS, Cushman M, Dentali F, Akl EA et al.| title=Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e195S-226S | pmid=22315261 | doi=10.1378/chest.11-2296 | pmc=PMC3278052 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315261  }} </ref>

===Long Travel===
{{main|Economy class syndrome}}

Economy class syndrome is the occurrence of venous thromboembolism (VTE) among air travelers.  Shown below is an algorithm for the indications of preventive measure for VTE among subjects undergoing a long travel.<ref name="pmid22315261">{{cite journal| author=Kahn SR, Lim W, Dunn AS, Cushman M, Dentali F, Akl EA et al.| title=Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e195S-226S | pmid=22315261 | doi=10.1378/chest.11-2296 | pmc=PMC3278052 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315261  }} </ref>

{{Family tree/start}}
{{familytree  | | | A01 | | | | A01= <div style="float: left; text-align: left; width: 20em; padding:1em;">'''Does the patient has any of the following that increase the risk of VTE?''' <br> ❑ Prior [[VTE]] episode <br>❑ Recent [[trauma]] <br> ❑ Recent [[surgery]] <br> ❑ Active [[cancer]] <br> ❑ Advanced age <br> ❑ Immobility<br> ❑ Severe [[obesity]] <br> ❑ [[Estrogen]] intake<br> ❑ [[Thrombophilia]] </div>}}
{{familytree  | |,|-|^|-|.| | | }}
{{familytree  | B01 | | B02 | | B01= Yes| B02= No}}
{{familytree  | |!| | | |!| | | }}
{{familytree  | C01 | | C02 | | C01= <div style="float: left; text-align: left; width: 15em; padding:1em;">Recommend VTE preventive measures:<br>❑ Calf muscle exercise <br> ❑ Frequent ambulation <br> ❑ To sit in an aisle seat <br> ❑ [[Graduated compression stockings]] below the knee (pressure: 15-30 mmHg)<br> ❑ No pharmacological VTE prophylaxis</div>| C02= ❑ No preventive measures are required}}
{{Family tree/end}}

===Asymptomatic Thrombophilia===
VTE prophylaxis is not recommended among subjects with asymptomatic [[thrombophilia]].<ref name="pmid22315261">{{cite journal| author=Kahn SR, Lim W, Dunn AS, Cushman M, Dentali F, Akl EA et al.| title=Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e195S-226S | pmid=22315261 | doi=10.1378/chest.11-2296 | pmc=PMC3278052 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315261  }} </ref>

===Non Hospitalized Subjects===
===Lifestyle Modifications===
Lifestyle modifications among subjects at elevated risk of VTE might be helpful to prevent [[thrombosis]], they include:
# [[Obesity]]
# Inactivity
# [[Cigarette smoking]]
# [[Dehydration]]
# [[Hypertension]]

==VTE Prevention in Non Orthopedic Surgical Patients==
===General and Abdominal-Pelvic Surgeries===
Shown below is an algorithm depicting the indications and choices of VTE prophylaxis among patients undergoing general and abdominal-pelvic surgeries.  Note that [[inferior vena cava]] filter is not recommended.  In addition, surveillance [[compression ultrasound]] should not be done to screen for VTE.<ref name="pmid22315263">{{cite journal| author=Gould MK, Garcia DA, Wren SM, Karanicolas PJ, Arcelus JI, Heit JA et al.| title=Prevention of VTE in nonorthopedic surgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e227S-77S | pmid=22315263 | doi=10.1378/chest.11-2297 | pmc=PMC3278061 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315263  }} </ref>

<span style="font-size:85%"> '''Abbreviations:''' '''LDUH:''' low dose [[unfractionated heparin]]; '''LMWH:''' [[low molecular weight heparin]]; '''UH:''' [[unfractionated heparin]]; '''VTE:''' [[venous thromboembolism]] </span>

{{Family tree/start}}
{{familytree  | | | | | | | | | A01 | | | | | | | | | A01= '''Assess the risk of VTE'''}}
{{familytree  | |,|-|-|-|v|-|-|-|+|-|-|-|-|-|-|-|.| | }}
{{familytree  | B01 | | B02 | | B03 | | | | | | B04 | | B01= '''Very low''' <br> <0.5% <br> OR <br> [[Rogers score]] <7 <br> OR <br> [[Caprini score]]=0| B02= '''Low''' <br> ~ 1.5% <br> OR <br> [[Rogers score]] 7-10<br> OR <br> [[Caprini score]] 1-2| B03= '''Moderate''' <br> ~ 3% <br> OR <br> [[Rogers score]] >10 <br> OR <br> [[Caprini score]] 3-4| B04= '''High''' <br> ~ 6% <br> OR <br> [[Caprini score]] ≥5}}
{{familytree  | |!| | | |!| | | | |!| | | | | | | |!| | | }}
{{familytree  | C01 | | C02 | | C03 | | | | | | C04 | | | | C01= <div style="float: left; text-align: left; width: 15em; padding:1em;">❑ Early ambulation <br> ❑ No mechanical VTE prophylaxis <br> ❑ No pharmacological VTE prophylaxis </div>| C02= <div style="float: left; text-align: left; width: 15em; padding:1em;">❑ Mechanical VTE prophylaxis <br> ([[Intermittent pneumatic compression]] is preferred)</div>| C03= Is the patient at high risk of [[bleeding]] <br> OR <br>Will bleeding cause severe consequences?| C04=Is the patient at high risk of bleeding <br>OR <br> Will bleeding cause severe consequences?}}
{{familytree  | | | | | | | |,|-|^|-|.| | | |,|-|^|-|.| | | }}
{{familytree  | | | | | | | D01 | | D02 | | D03 | | D04 | | D01= No| D02= Yes| D03= No| D04= Yes}}
{{familytree  | | | | | | | |!| | | |!| | | |!| | | |!| | | }}
{{familytree  | | | | | | | E01 | | E02 | | E03 | | E04 | | E01= <div style="float: left; text-align: left; width: 15em; padding:1em;">❑ [[LMWH]] <br> OR <br> ❑ [[LDUH]] <br> OR <br> ❑ Mechanical VTE prophylaxis <br>([[Intermittent pneumatic compression]] is preferred) </div>| E02= ❑ Mechanical VTE prophylaxis <br> ([[Intermittent pneumatic compression]] is preferred)| E03= Are [[LMWH]] or [[UH]] contraindicated?| E04= ❑ Mechanical VTE prophylaxis <br> ([[Intermittent pneumatic compression]] is preferred)}}
{{familytree  | | | | | | | | | | | | | |,|-|^|-|.| | | | | }}
{{familytree  | | | | | | | | | | | | | F01 | | F02 | | | | F01= No| F02= Yes}}
{{familytree  | | | | | | | | | | | | | |!| | | |!| | | | | }}
{{familytree  | | | | | | | | | | | | | G01 | | G02 | | | | G01= Does the patient have [[cancer]]?| G02= <div style="float: left; text-align: left; width: 15em; padding:1em;">❑ Low dose [[aspirin]] <br> OR <br> ❑ [[Fondaparinux]] <br> OR <br> ❑ Mechanical VTE prophylaxis <br> ([[Intermittent pneumatic compression]] is preferred)</div>}}
{{familytree  | | | | | | | | | | | |,|-|^|-|.| | }}
{{familytree  | | | | | | | | | | | H01 | | H02 | H01= No| H02= Yes}}
{{familytree  | | | | | | | | | | | |!| | | |!| | }}
{{familytree  | | | | | | | | | | | I01 | | I02 | I01= '''Pharmacological VTE prophylaxis ''' <br> <div style="float: left; text-align: left; width: 15em; padding:1em;">❑ [[LMWH]] <br> OR <br> ❑ [[LDUH]] </div><br> '''PLUS''' <br> '''Mechanical VTE prophylaxis'''
<div style="float: left; text-align: left; width: 15em; padding:1em;">
❑ [[Elastic stockings]] <br>
❑ [[Intermittent pneumatic compression]]</div>| I02= '''Pharmacological VTE prophylaxis''' <br> ❑ Extended treatment with [[LMWH]] for 4 weeks <br> '''PLUS''' <br> '''Mechanical VTE prophylaxis'''
<div style="float: left; text-align: left; width: 15em; padding:1em;">
❑ [[Elastic stockings]]
❑ [[Intermittent pneumatic compression]] </div>}}
{{Family tree/end}}

===Cardiac Surgery===
<span style="font-size:85%"> '''Abbreviations:''' '''LDUH:''' low dose [[unfractionated heparin]]; '''LMWH:''' [[low molecular weight heparin]]; '''VTE:''' [[venous thromboembolism]] </span>

{{Family tree/start}}
{{familytree  | | | A01 | | | | A01= Is the postoperative period prolonged by<br> one or more non hemorrhagic surgical complications?}}
{{familytree  | |,|-|^|-|.| | | }}
{{familytree  | B01 | | B02 | | B01= Yes| B02= No <br> (Uncomplicated post-op period)}}
{{familytree  | |!| | | |!| | | }}
{{familytree  | C01 | | C02 | | C01= '''Pharmacological VTE prophylaxis''' <br> <div style="float: left; text-align: left; width: 15em; padding:1em;">❑ [[LDUH]] <br> OR <br> ❑ [[LMWH]] </div> <br><br> '''PLUS'''<br><br> '''Mechanical VTE prophylaxis''' | C02= '''Mechanical VTE prophylaxis''' <br>  (Intermittent pneumatic compression is preferred)}}
{{Family tree/end}}

===Thoracic Surgery===
<span style="font-size:85%"> '''Abbreviations:''' '''LDUH:''' low dose [[unfractionated heparin]]; '''LMWH:''' [[low molecular weight heparin]]; '''VTE:''' [[venous thromboembolism]] </span>

{{Family tree/start}}
{{familytree  | | | | | | | A01 | | | | | | A01= <div style="float: left; text-align: left;padding:1em;">'''Is the patient undergoing ANY of the following surgeries that are associated with a high risk of VTE?''' <br>❑ Pulmonary resection<br>❑ Pneumonectomy<br>❑ Extrapleural pneumonectomy<br>❑ Esophagectomy </div>}}
{{familytree  | | | |,|-|-|-|^|-|-|-|.| | | }}
{{familytree  | | | B01 | | | | | | B02 | | B01= Yes| B02= No}}
{{familytree  | | | |!| | | | | | | |!| | | }}
{{familytree  | | | B03 | | | | | | B04 | | B03= '''Patient is at HIGH risk of VTE'''| B04= '''Patient is at MODERATE risk for VTE'''}}
{{familytree  | | | |!| | | | | | | |!| | | }}
{{familytree  | | | C01 | | | | | | C02 | | C01= Is the patient at high risk for major bleeding?| C02= Is the patient at high risk for major bleeding?}}
{{familytree  | |,|-|^|-|.| | | |,|-|^|-|.| |}}
{{familytree  | D01 | | D02 | | D03 | | D04 | D01= No| D02= Yes| D03= No| D04= Yes}}
{{familytree  | |!| | | |!| | | |!| | | |!| | }}
{{familytree  | E01 | | E02 | | E03 | | E04 | E01= '''Pharmacological VTE prophylaxis''' <br> <div style="float: left; text-align: left;padding:1em;" >❑ [[LDUH]] <br> OR <br> ❑ [[LMWH]] </div> <br> <br>  '''PLUS'''<br><br> '''Mechanical VTE prophylaxis''' <br> <div style="float: left; text-align: left;padding:1em;" >❑ [[Elastic stocking]] <br>❑ [[Intermittent pneumatic compression]] </div>| E02= '''Mechanical VTE prophylaxis''' <br> ([[Intermittent pneumatic compression]] is preferred) <br><br>  '''Pharmacological VTE prophylaxis''' <br> '''''When the risk of bleeding subsides''''' <div style="float: left; text-align: left;padding:1em;"> <br>❑ [[LDUH]] <br> OR <br>❑ [[LMWH]] </div>| E03= <div style="float: left; text-align: left;padding:1em;"> ❑ [[LDUH]] <br> OR <br>❑ [[LMWH]] <br> OR <br >❑ Mechanical VTE prophylaxis <br> ([[Intermittent pneumatic compression]] is preferred)</div>| E04= '''Mechanical VTE prophylaxis''' <br> ([[Intermittent pneumatic compression]] is preferred) <br><br> '''Pharmacological VTE prophylaxis''' <br> '''''When the risk of bleeding subsides''''' <br> <div style="float: left; text-align: left;padding:1em;"> ❑ [[LDUH]] <br> OR <br>❑ [[LMWH]] </div>}}
{{Family tree/end}}

===Craniotomy===
There is no validated risk score for the occurrence of subsequent VTE or for bleeding, particularly [[intracranial hemorrhage]] among patients undergoing [[craniotomy]].  Since the risk for [[intracranial hemorrhage]] is the highest within the first 12 to 24 hours following [[craniotomy]], pharmacological therapy should be delayed until the risk of bleeding subsides.
{{Family tree/start}}
{{familytree | | | A01 | | | A01= '''Is the patient undergoing craniotomy for a malignancy?'''}}
{{familytree | |,|-|^|-|.| | }}
{{familytree | B01 | | B02 | B01= Yes| B02= No}}
{{familytree | |!| | | |!| | }}
{{familytree | C01 | | C02 | C01= '''Very high risk of VTE (≥ 10%)'''| C02= '''High risk of VTE (~ 5%)'''}}
{{familytree | |!| | | |!| | }}
{{familytree | D01 | | D02 | D01= '''Mechanical VTE prophylaxis''' <br> (Intermittent pneumatic compression is preferred)<br><br> '''PLUS''' <br><br>'''Pharmacological VTE prophylaxis'''<br> '''''when the risk of bleeding subsides'''''| D02= '''Mechanical VTE prophylaxis''' <br> (Intermittent pneumatic compression is preferred) }}
{{Family tree/end}}

===Spinal Surgery===
{{Family tree/start}}
{{familytree | | | A01 | | | A01= '''Is the patient undergoing spinal surgery for malignancy'''<br> '''OR''' <br> '''undergoing surgery with a combined anterior-posterior approach?'''}}
{{familytree | |,|-|^|-|.| | }}
{{familytree | B01 | | B02 | B01= Yes| B02= No}}
{{familytree | |!| | | |!| | }}
{{familytree | C01 | | C02 | C01= '''High risk for VTE'''| C02= '''Low risk for VTE''' }}
{{familytree | |!| | | |!| | }}
{{familytree | D01 | | D02 | D01= '''Mechanical VTE prophylaxis''' <br> (Intermittent pneumatic compression is preferred)<br><br> '''PLUS''' <br><br>'''Pharmacological VTE prophylaxis'''  when the risk of bleeding subsides| D02= '''Mechanical VTE prophylaxis''' <br> (Intermittent pneumatic compression is preferred) }}
{{Family tree/end}}

===Trauma===
Shown below is an algorithm depicting the indications and choices of VTE prophylaxis among patients with major trauma.  Major trauma include traumatic [[brain]] or [[spine]] injury.  Note that [[inferior vena cava]] filter is not recommended.  In addition, surveillance [[compression ultrasound]] should not be done to screen for VTE.<ref name="pmid22315263">{{cite journal| author=Gould MK, Garcia DA, Wren SM, Karanicolas PJ, Arcelus JI, Heit JA et al.| title=Prevention of VTE in nonorthopedic surgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e227S-77S | pmid=22315263 | doi=10.1378/chest.11-2297 | pmc=PMC3278061 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315263  }} </ref>

<span style="font-size:85%"> '''Abbreviations:''' '''LDUH:''' low dose [[unfractionated heparin]]; '''LMWH:''' [[low molecular weight heparin]]; '''VTE:''' [[venous thromboembolism]] </span>

{{Family tree/start}}
{{familytree | | | A01 | | | A01=<div style="float: left; text-align: left;padding:1em;">'''Does the patient who has a major trauma have any contraindications for [[LDUH]] or [[LMWH]]?''' </div>}}
{{familytree | |,|-|^|-|.| | }}
{{familytree | C01 | | C02 | C01= No| C02= Yes}}
{{familytree | |!| | | |!| | }}
{{familytree | D01 | | D02 | D01= <div style="float: left; text-align: left;padding:1em;">'''Pharmacological VTE prophylaxis'''<br>
❑ [[LDUH]] <br>OR <br> ❑ [[LMWH]] <br> <br> '''PLUS''' <br> <br>'''Mechanical VTE prophylaxis''' <br> (Intermittent pneumatic compression is preferred)</div>| D02= <div style="float: left; text-align: left;padding:1em;">'''Mechanical VTE prophylaxis''' <br> (Intermittent pneumatic compression is preferred)<br><br> '''PLUS''' <br><br>'''Pharmacological VTE prophylaxis''' <br> when the risk of bleeding subsides </div>}}
{{familytree/end}}

==VTE Prevention in Orthopedic Patients==
===Major Orthopedic Surgery===
Shown below is an algorithm depicting VTE prophylaxis in patients undergoing major orthopedic surgeries which include '''total hip arthroplasty''', '''total knee arthroplasty''' and '''hip fracture surgery'''.  Among patients who are not at elevated risk of bleeding, [[LMWH]] is the first line choice for VTE therapy.  Among patients who refuse [[LMWH]] injection or intermittent pneumatic compression device, apixaban or dabigatran can be administered. Do not consider [[inferior vena cava filter]] as VTE prophylaxis or screening with a compression ultrasound for VTE.<ref name="pmid22315265">{{cite journal| author=Falck-Ytter Y, Francis CW, Johanson NA, Curley C, Dahl OE, Schulman S et al.| title=Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e278S-325S | pmid=22315265 | doi=10.1378/chest.11-2404 | pmc=PMC3278063 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315265  }} </ref>

<span style="font-size:85%"> '''Abbreviations:''' '''LDUH:''' low dose [[unfractionated heparin]]; '''LMWH:''' [[low molecular weight heparin]]; '''VKA:''' [[Vitamin K antagonist]]; '''VTE:''' [[venous thromboembolism]] </span>

{{Family tree/start}}
{{familytree | | | A01 | | | | | | A01= '''What is the risk of bleeding of the patient undergoing the major orthopedic surgery?'''}}
{{familytree | |,|-|^|-|.| | | | | }}
{{familytree | B01 | | B02 | | | | B01= High| B02= Low}}
{{familytree | |!| | | |!| | | | | }}
{{familytree | C01 | | C02 | | | | C01= ❑ [[Intermittent pneumatic compression]]| C02= '''What is the type of the orthopedic surgery?'''}}
{{familytree | | | |,|-|^|-|.| | | }}
{{familytree | | | D01 | | D02 | | D01= '''Total hip [[arthroplasty]]''' <br>OR <br> '''Total knee [[arthroplasty]]'''| D02= '''Hip fracture surgery'''}}
{{familytree | | | |!| | | |!| | | }}
{{familytree | | | E01 | | E02 | E01= <div style="float: left; text-align: left;padding:1em;">'''Pharmacological VTE prophylaxis'''<br>
: '''''Begin at least 12 hours before and 12 hours after the surgery'''''<br>
: '''''Administer for at least 14 days''''' <br>
: '''''Extend the therapy to 35 days as outpatient''''' <br>
Choose ONE of the following: <br> ❑ [[LMWH]] (first line)<br> ❑ [[Fondaparinux]] <br> ❑ [[Apixaban]] <br> ❑ [[Dabigatran]] <br> ❑ [[Rivaroxaban]] <br> ❑ [[LDUH]] <br> ❑ [[VKA]] <br> ❑ [[Aspirin]]<br> <br> '''AND/OR''' <br> <br>'''Intermittent pneumatic compression device'''</div>| E02=  <div style="float: left; text-align: left;padding:1em;">'''Pharmacological VTE prophylaxis'''<br>
: '''''Begin at least 12 hours before and 12 hours after the surgery'''''<br>
: '''''Administer for at least 14 days''''' <br>
: '''''Extend the therapy to 35 days as outpatient''''' <br>
Choose ONE of the following: <br> ❑ [[LMWH]] (first line)<br> ❑ [[Fondaparinux]] <br> ❑ [[LDUH]] <br>❑ [[VKA]] <br> ❑ [[Aspirin]]<br> <br> '''AND/OR''' <br> <br>'''Intermittent pneumatic compression device'''</div>}}
{{Family tree/end}}

====Assessment of Bleeding in Major Orthopedic Surgeries====
There is no score to estimate the risk of bleeding in major orthopedic surgeries.  However, some factors have been identified to increase the risk of bleeding in this category of patients.  These factors include:<ref name="pmid22315265">{{cite journal| author=Falck-Ytter Y, Francis CW, Johanson NA, Curley C, Dahl OE, Schulman S et al.| title=Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e278S-325S | pmid=22315265 | doi=10.1378/chest.11-2404 | pmc=PMC3278063 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315265  }} </ref>
* Prior major [[bleeding]]
* Severe [[kidney failure]]
* Concomitant administration of an [[antiplatelet]]
* [[Bleeding]] during the current surgery which was difficult to control
* Extensive surgical dissection
* Revision surgery

===Isolated Lower-Leg Injuries===
VTE prophylaxis is not recommended among patients who have isolated lower leg injuries distal to the knee.<ref name="pmid22315265">{{cite journal| author=Falck-Ytter Y, Francis CW, Johanson NA, Curley C, Dahl OE, Schulman S et al.| title=Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e278S-325S | pmid=22315265 | doi=10.1378/chest.11-2404 | pmc=PMC3278063 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315265  }} </ref>

===Knee Arthroscopy===
VTE prophylaxis is not recommended among patients who undergo knee arthroscopy and who have no previous VTE episodes.<ref name="pmid22315265">{{cite journal| author=Falck-Ytter Y, Francis CW, Johanson NA, Curley C, Dahl OE, Schulman S et al.| title=Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. | journal=Chest | year= 2012 | volume= 141 | issue= 2 Suppl | pages= e278S-325S | pmid=22315265 | doi=10.1378/chest.11-2404 | pmc=PMC3278063 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22315265  }} </ref>

==2012 American College of Chest Physicians Evidence-Based Clinical Practice Guidelines: Recommendations for Prevention of VTE in Nonorthopedic Surgical Patients (DO NOT EDIT)<ref name="pmid22315263">{{cite journal |author=Gould MK, Garcia DA, Wren SM, ''et al.'' |title=Prevention of VTE in nonorthopedic surgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e227S–77S |year=2012 |month=February |pmid=22315263 |doi=10.1378/chest.11-2297 |url=}}</ref>==

===General Surgery, GI surgery, Urological surgery and Gynecologic surgery, Bariatric surgery, Vascular surgery, and Plastic and Reconstructive surgery (DO NOT EDIT)<ref name="pmid22315263">{{cite journal |author=Gould MK, Garcia DA, Wren SM, ''et al.'' |title=Prevention of VTE in nonorthopedic surgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e227S–77S |year=2012 |month=February |pmid=22315263 |doi=10.1378/chest.11-2297 |url=}}</ref>===

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LightGreen"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 1]]
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''1.''' For general and abdominal-pelvic surgery patients at very low risk for VTE ( < 0.5%; Rogers score, <7; Caprini score, 0), we recommend that no specific pharmaclogic prophylaxis be used other than early ambulation ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])''.<nowiki>"</nowiki>
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''2.''' For general and abdominal-pelvic surgery patients at high risk for VTE (~6.0%; Caprini score,≥5) who are not at high risk for major bleeding complications, we recommend pharmacologic prophylaxis with LMWH ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])'' or LDUH ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])'' over no prophylaxis. <nowiki>"</nowiki>
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''3.''' For high-VTE-risk patients undergoing abdominal or pelvic surgery for cancer who are not otherwise at high risk for major bleeding complications, we recommend extended duration pharmacologic  prophylaxis (4 weeks) with LMWH over limited-duration prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])''.<nowiki>"</nowiki>
|}
{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' For general and abdominal-pelvic surgery patients at very low risk for VTE ( < 0.5%; Rogers score, <7; Caprini score, 0), we recommend that no specific mechanical prophylaxis be used other than early ambulation.''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' <nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' For general and abdominal-pelvic surgery patients at low risk for VTE (~1.5%; Rogers score, 7-10; Caprini score, 1-2), we suggest mechanical prophylaxis, preferably with intermittent pneumatic compression (IPC), over no prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''. <nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''3.''' For general and abdominal-pelvic surgery patients at moderate risk for VTE (~3.0%; Rogers score, >10; Caprini score, 3-4) who are not at high risk for major bleeding complications, we suggest low-molecular-weight heparin (LMWH) ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])'', low-dose unfractionated heparin (LDUH) ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])'' , or mechanical prophylaxis, preferably with IPC ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' , over no prophylaxis. <nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''4.''' For general and abdominal-pelvic surgery patients at moderate risk for VTE (3.0%; Rogers score, > 10; Caprini score, 3-4) who are at high risk for major bleeding complications or those in whom the consequences of bleeding are thought to be particularly severe, we suggest mechanical prophylaxis, preferably with IPC, over no prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' . <nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''5.''' For general and abdominal-pelvic surgery patients at high risk for VTE (~6.0%; Caprini score,≥5) who are not at high risk for major bleeding complications, we suggest that mechanical prophylaxis with elastic stockings (ES) or IPC should be added to pharmacologic prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''. <nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''6.''' For high-VTE-risk general and abdominal-pelvic surgery patients who are at high risk for major bleeding complications or those in whom the consequences of bleeding are thought to be particularly severe, we suggest use of mechanical prophylaxis, preferably with IPC, over no prophylaxis until the risk of bleeding diminishes and pharmacologic prophylaxis may be initiated ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''. <nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''7.''' For general and abdominal-pelvic surgery patients at high risk for VTE (6%; Caprini score,≥5) in whom both LMWH and unfractionated heparin are contraindicated or unavailable and who are not at high risk for major bleed ing complications, we suggest low-dose aspirin ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' , fondaparinux ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' , or mechanical prophylaxis, preferably with IPC ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' , over no prophylaxis. <nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''8.''' For general and abdominal-pelvic surgery patients, we suggest that an inferior vena cava (IVC) filter should not be used for primary VTE prevention ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''. <nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''9.''' For general and abdominal-pelvic surgery patients, we suggest that periodic surveillance with venous compression ultrasound (VCU) should not be performed ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' . <nowiki>"</nowiki>
|}

===Recommendations for Prevention of VTE in Cardiac Surgery Patients (DO NOT EDIT)<ref name="pmid22315263">{{cite journal |author=Gould MK, Garcia DA, Wren SM, ''et al.'' |title=Prevention of VTE in nonorthopedic surgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e227S–77S |year=2012 |month=February |pmid=22315263 |doi=10.1378/chest.11-2297 |url=}}</ref>===
{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' For cardiac surgery patients with an uncomplicated postoperative course, we suggest use of mechanical prophylaxis, preferably with optimally applied IPC, over either no prophylaxis (Grade 2C) or pharmacologic prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' For cardiac surgery patients whose hospital course is prolonged by one or more nonhemorrhagic surgical complications, we suggest adding pharmacologic prophylaxis with LDUH or LMWH to mechanical prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.
|}

===Recommendations for Prevention of VTE in Thoracic Surgery Patients (DO NOT EDIT)<ref name="pmid22315263">{{cite journal |author=Gould MK, Garcia DA, Wren SM, ''et al.'' |title=Prevention of VTE in nonorthopedic surgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e227S–77S |year=2012 |month=February |pmid=22315263 |doi=10.1378/chest.11-2297 |url=}}</ref>===
{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LightGreen"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 1]]
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''1.''' For thoracic surgery patients at high risk for VTE who are not at high risk for perioperative bleeding, we suggest LDUH ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])'' or LMWH ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])''<nowiki>"</nowiki>.
|}

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' For thoracic surgery patients at moderate risk for VTE who are not at high risk for perioperative bleeding, we suggest LDUH ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])'', LMWH ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])'', or mechanical prophylaxis with optimally applied IPC ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' over no prophylaxis.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' For thoracic surgery patients at high risk for VTE who are not at high risk for perioperative bleeding, we suggest that mechanical prophylaxis with ES or IPC should be added to pharmacologic prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''3.''' For thoracic surgery patients who are at high risk for major bleeding, we suggest use of mechanical prophylaxis, preferably with optimally applied IPC, over no prophylaxis until the risk of bleeding diminishes and pharmacologic prophylaxis may be initiated ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|}

===Recommendations for Prevention of VTE in Patients undergoing Craniotomy (DO NOT EDIT)<ref name="pmid22315263">{{cite journal |author=Gould MK, Garcia DA, Wren SM, ''et al.'' |title=Prevention of VTE in nonorthopedic surgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e227S–77S |year=2012 |month=February |pmid=22315263 |doi=10.1378/chest.11-2297 |url=}}</ref>===
{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' For craniotomy patients, we suggest that mechanical prophylaxis, preferably with IPC, be used over no prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])'' or pharmacologic prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''. <nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' For craniotomy patients at very high risk for VTE (eg, those undergoing craniotomy for malignant disease), we suggest adding pharmacologic prophylaxis to mechanical prophylaxis once adequate hemostasis is established and the risk of bleeding decreases ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''. <nowiki>"</nowiki>
|}

===Recommendations for Prevention of VTE in Spinal Surgery Patients (DO NOT EDIT)<ref name="pmid22315263">{{cite journal |author=Gould MK, Garcia DA, Wren SM, ''et al.'' |title=Prevention of VTE in nonorthopedic surgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e227S–77S |year=2012 |month=February |pmid=22315263 |doi=10.1378/chest.11-2297 |url=}}</ref>===
{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' For patients undergoing spinal surgery, we suggest mechanical prophylaxis, preferably with IPC, over no prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'', unfractionated heparin ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'', or LMWH ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' For patients undergoing spinal surgery at high risk for VTE (including those with malignant disease or those undergoing surgery with a combined anterior-posterior approach), we suggest adding pharmacologic prophylaxis to mechanical prophylaxis once adequate hemostasis is established and the risk of bleeding decreases ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|}

===Recommendations for Prevention of VTE in Major Trauma Patients (DO NOT EDIT)<ref name="pmid22315263">{{cite journal |author=Gould MK, Garcia DA, Wren SM, ''et al.'' |title=Prevention of VTE in nonorthopedic surgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e227S–77S |year=2012 |month=February |pmid=22315263 |doi=10.1378/chest.11-2297 |url=}}</ref>===
{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' For major trauma patients, we suggest use of LDUH ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'', LMWH ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'', or mechanical prophylaxis, preferably with IPC ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'', over no prophylaxis.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' For major trauma patients at high risk for VTE (including those with acute spinal cord injury, traumatic brain injury, and spinal surgery for trauma), we suggest adding mechanical prophylaxis to pharmacologic prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' when not contraindicated by lower extremity injury.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''3.''' For major trauma patients in whom LMWH and LDUH are contraindicated, we suggest mechanical prophylaxis, preferably with IPC, over no prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' when not contraindicated by lower-extremity injury. We suggest adding pharmacologic prophylaxis with either LMWH or LDUH when the risk of bleeding diminishes or the contraindication to heparin resolves ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''4.''' For major trauma patients, we suggest that an IVC filter should not be used for primary VTE prevention ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''5.''' For major trauma patients, we suggest that periodic surveillance with VCU should not be performed ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|}

==2012 American College of Chest Physicians Evidence-Based Clinical Practice Guidelines: Recommendations for Prevention of VTE in Orthopedic Surgery Patients (DO NOT EDIT)<ref name="pmid22315265">{{cite journal |author=Falck-Ytter Y, Francis CW, Johanson NA, ''et al.'' |title=Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e278S–325S |year=2012 |month=February |pmid=22315265 |doi=10.1378/chest.11-2404 |url=}}</ref>==
===Recommendations for Prevention of VTE in Patients Undergoing Major Orthopedic Surgery: THA, TKA, HFS (DO NOT EDIT)<ref name="pmid22315265">{{cite journal |author=Falck-Ytter Y, Francis CW, Johanson NA, ''et al.'' |title=Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e278S–325S |year=2012 |month=February |pmid=22315265 |doi=10.1378/chest.11-2404 |url=}}</ref>===

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LightGreen"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 1]]
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''1.''' In patients undergoing total hip arthro- plasty (THA) or total knee arthroplasty (TKA), we recommend use of one of the following for a minimum of 10 to 14 days rather than no anti-thrombotic prophylaxis: low-molecular-weight heparin (LMWH), fondaparinux, apixaban, dab- igatran, rivaroxaban, low-dose unfractionated heparin (LDUH), adjusted-dose vitamin K antag- onist (VKA), aspirin (all of ''[[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]]''), or an inter- mittent pneumatic compression device (IPCD) (''[[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]]''). <nowiki>"</nowiki>
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''2.''' In patients undergoing hip fracture surgery (HFS), we recommend use of one of the following rather than no antithrombotic prophylaxis for a minimum of 10 to 14 days: LMWH, fondaparinux, LDUH, adjusted-dose VKA, aspirin (all Grade 1B) , or an IPCD ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' .<nowiki>"</nowiki>
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''3.''' For patients undergoing major orthopedic surgery (THA, TKA, HFS) and receiving LMWH as thromboprophylaxis, we recommend starting either 12 h or more preoperatively or 12 h or more postoperatively rather than within 4 h or less preoperatively or 4 h or less postoperatively ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])''.<nowiki>"</nowiki>
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''4.''' In patients undergoing major orthopedic surgery and who decline or are uncooperative with injections or an IPCD, we recommend using apixaban or dabigatran (alternatively rivaroxaban or adjusted-dose VKA if apixaban or dabigatran are unavailable) rather than alternative forms of prophylaxis (all of ''[[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]]'').
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''5.''' For asymptomatic patients following major orthopedic surgery, we recommend against Doppler (or duplex) ultrasound (DUS) screening before hospital discharge ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])''.<nowiki>"</nowiki>
|}

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' In patients undergoing THA or TKA, irrespective of the concomitant use of an IPCD or length of treatment, we suggest the use of LMWH in preference to the other agents we have recommended as alternatives: fondaparinux,apixaban, dabigatran, rivaroxaban, LDUH (all of ''[[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]]'') , adjusted-dose VKA, or aspirin (all of ''[[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]]'').<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' In patients undergoing HFS, irrespective of the concomitant use of an IPCD or length of treatment, we suggest the use of LMWH in preference to the other agents we have recommended as alternatives: fondaparinux, LDUH (''[[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]]'') , adjusted-dose VKA, or aspirin (all of ''[[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]]'').<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''3.''' For patients undergoing major orthopedic surgery, we suggest extending thromboprophylaxis in the outpatient period for up to 35 days from the day of surgery rather than for only 10 to 14 days ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])''.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''4.''' In patients undergoing major orthopedic surgery, we suggest using dual prophylaxis with an antithrombotic agent and an IPCD during the hospital stay ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''5.''' In patients undergoing major orthopedic surgery and increased risk of bleeding, we suggest using an IPCD or no prophylaxis rather than pharmacologic treatment ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''6.''' In patients undergoing major orthopedic surgery, we suggest against using inferior vena cava (IVC) filter placement for primary prevention over no thromboprophylaxis in patients with an increased bleeding risk or contraindications to both pharmacologic and mechanical thromboprophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' .<nowiki>"</nowiki>
|}

===Recommendations for Prevention of VTE in Isolated Lower-Leg Injuries Distal to the Knee (DO NOT EDIT)<ref name="pmid22315265">{{cite journal |author=Falck-Ytter Y, Francis CW, Johanson NA, ''et al.'' |title=Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e278S–325S |year=2012 |month=February |pmid=22315265 |doi=10.1378/chest.11-2404 |url=}}</ref>===

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' We suggest no prophylaxis rather than pharmacologic thromboprophylaxis in patients with isolated lower-leg injuries requiring leg immobilization ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|}

===Recommendations for Prevention of VTE in patients undergoing Knee Arthroscopy (DO NOT EDIT)<ref name="pmid22315265">{{cite journal |author=Falck-Ytter Y, Francis CW, Johanson NA, ''et al.'' |title=Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e278S–325S |year=2012 |month=February |pmid=22315265 |doi=10.1378/chest.11-2404 |url=}}</ref>===

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' For patients undergoing knee arthroscopy without a history of prior VTE, we suggest no thromboprophylaxis rather than prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])''.<nowiki>"</nowiki>
|}

==2012 American College of Chest Physicians Evidence-Based Clinical Practice Guidelines: Recommendations for Prevention of VTE in Nonsurgical Patients (DO NOT EDIT)<ref name="pmid22315261">{{cite journal |author=Kahn SR, Lim W, Dunn AS, ''et al.'' |title=Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e195S–226S |year=2012 |month=February |pmid=22315261 |doi=10.1378/chest.11-2296 |url=}}</ref>==
===Recommendations for Prevention of VTE in Hospitalized Acutely Ill Medical Patients (DO NOT EDIT)<ref name="pmid22315261">{{cite journal |author=Kahn SR, Lim W, Dunn AS, ''et al.'' |title=Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e195S–226S |year=2012 |month=February |pmid=22315261 |doi=10.1378/chest.11-2296 |url=}}</ref>===

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LightGreen"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 1]]
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''1.''' For acutely ill hospitalized medical patients at increased risk of thrombosis, we recommend anticoagulant thromboprophylaxis with low molecular-weight heparin [LMWH], low-dose unfractionated heparin (LDUH) bid, LDUH did, or fondaparinux (Grade 1B).<nowiki>"</nowiki>
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''2.''' For acutely ill hospitalized medical patients at low risk of thrombosis, we recommend against the use of pharmacologic prophylaxis or mechanical prophylaxis (Grade 1B).<nowiki>"</nowiki>
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''3.''' For acutely ill hospitalized medical patients who are bleeding or at high risk for bleeding, we recommend against anticoagulant thromboprophylaxis (Grade 1B).<nowiki>"</nowiki>
|}
{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' For acutely ill hospitalized medical patients at increased risk of thrombosis who are bleeding or at high risk for major bleeding, we suggest the optimal use of mechanical thromboprophylaxis with graduated compression stockings (GCS) (Grade 2C) or intermittent pneumatic compression (IPC) (Grade 2C), rather than no mechanical thromboprophylaxis. When bleeding risk decreases, and if VTE risk persists, we suggest that pharmacologic thromboprophylaxis be substituted for mechanical thromboprophylaxis (Grade 2B).<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' In acutely ill hospitalized medical patients who receive an initial course of thromboprophylaxis, we suggest against extending the duration of thromboprophylaxis beyond the period of patient immobilization or acute hospital stay (Grade 2B).<nowiki>"</nowiki>
|}

===Recommendations for Prevention of VTE in Critically Ill Patients (DO NOT EDIT)<ref name="pmid22315261">{{cite journal |author=Kahn SR, Lim W, Dunn AS, ''et al.'' |title=Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e195S–226S |year=2012 |month=February |pmid=22315261 |doi=10.1378/chest.11-2296 |url=}}</ref>===

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' In critically ill patients, we suggest against routine ultrasound screening for DVT ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' For critically ill patients, we suggest using LMWH or LDUH thromboprophylaxis over no prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''3.''' For critically ill patients who are bleeding, or are at high risk for major bleeding, we suggest mechanical thromboprophylaxis with GCS ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' or IPC ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])'' until the bleeding risk decreases, rather than no mechanical thromboprophylaxis. When bleeding risk decreases, we suggest that pharmacologic thromboprophylaxis be substituted for mechanical thromboprophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|}

===Recommendations for Prevention of VTE in Patients With Cancer in the Outpatient Setting (DO NOT EDIT)<ref name="pmid22315261">{{cite journal |author=Kahn SR, Lim W, Dunn AS, ''et al.'' |title=Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines |journal=Chest |volume=141 |issue=2 Suppl |pages=e195S–226S |year=2012 |month=February |pmid=22315261 |doi=10.1378/chest.11-2296 |url=}}</ref>===

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LightGreen"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 1]]
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''1.''' In outpatients with cancer who have no additional risk factors for VTE, we recommend against the prophylactic use of vitamin K antagonists ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])''.<nowiki>"</nowiki>
|}
{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' In outpatients with cancer who have no additional risk factors for VTE, we suggest against routine prophylaxis with LMWH or LDUH ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])''.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' In outpatients with solid tumors who have additional risk factors for VTE and who are at low risk of bleeding, we suggest prophylactic dose LMWH or LDUH over no prophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])''.<nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''3.''' In outpatients with cancer and indwelling central venous catheters, we suggest against routine prophylaxis with LMWH or LDUH ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence B]])'' and suggest against the prophylactic use of vitamin K antagonists ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''.<nowiki>"</nowiki>
|}

===Recommendations for Prevention of VTE in Chronically Immobilized Outpatients (DO NOT EDIT)<ref name="pmid22315261">Kahn SR, Lim W, Dunn AS, et al. (February 2012). "Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest 141 (2 Suppl): e195S–226S. doi:10.1378/chest.11-2296. PMID 22315261.</ref>===

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' In chronically immobilized persons residing at home or at a nursing home, we suggest against the routine use of thromboprophylaxis ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''<nowiki>"</nowiki>.
|}

===Recommendations for Thromboprophylaxis during Long-Distance Travel (DO NOT EDIT)<ref name="pmid22315261">Kahn SR, Lim W, Dunn AS, et al. (February 2012). "Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest 141 (2 Suppl): e195S–226S. doi:10.1378/chest.11-2296. PMID 22315261.</ref>===

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 2]]
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' For long-distance travelers at increased risk of VTE (including previous VTE, recent surgery or trauma, active malignancy, pregnancy, estrogen use, advanced age, limited mobility, severe obesity, or known thrombophilic disorder), we suggest frequent ambulation, calf muscle exercise, or sitting in an aisle seat if feasible ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''. <nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' For long-distance travelers at increased risk of VTE (including previous VTE, recent surgery or trauma, active malignancy, pregnancy, estrogen use, advanced age, limited mobility, severe obesity, or known thrombophilic disorder), we suggest use of properly fitted, below-knee GCS providing 15 to 30 mmHg of pressure at the ankle during travel ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''. For all other long-distance travelers, we suggest against the use of GCS ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''. <nowiki>"</nowiki>
|-
|bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''3.''' For long-distance travelers, we suggest against the use of aspirin or anticoagulants to prevent VTE ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''. <nowiki>"</nowiki>
|}

===Recommendations for Thromboprophylaxis to Prevent VTE in Asymptomatic Persons With Thrombophilia (DO NOT EDIT)<ref name="pmid22315261">Kahn SR, Lim W, Dunn AS, et al. (February 2012). "Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest 141 (2 Suppl): e195S–226S. doi:10.1378/chest.11-2296. PMID 22315261.</ref>===

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LightGreen"|[[ACCP guidelines classification scheme#Grading Scheme Classification|Grade 1]]
|-
| bgcolor="LightGreen"| <nowiki>"</nowiki>'''1.''' In persons with asymptomatic thrombophilia (ie, without a previous history of VTE), we recommend against the long-term daily use of mechanical or pharmacologic thromboprophylaxis to prevent VTE ''([[ACCP guidelines classification scheme#Level of Evidence|Level of evidence C]])''. <nowiki>"</nowiki>
|}

==References==

{{reflist|2}}

[[Category:Disease]]
[[Category:Cardiology]]
[[Category:Hematology]]
[[Category:Angiology]]
[[Category:Emergency medicine]]
[[Category:Vascular surgery]]
[[Category:Up-To-Date]]
[[Category:Cardiovascular diseases]]

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