Deep vein thrombosis prevention

Resident Survival Guide

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Editor(s)-In-Chief: The APEX Trial Investigators, C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Cafer Zorkun, M.D., Ph.D. [2]; Kashish Goel, M.D.; Justine Cadet; Rim Halaby, M.D. [3]

For information on randomized trials which compared the efficacy and safety of antithrombins and anticoagulants in the prevention of deep vein thrombosis, click here

Synonyms and keywords: 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:

• Non surgical patients
  • Assessment of Risks
  • Hospitalized Acutely ill Medical Patients
  • Critically-ill hospitalized patients
  • Cancer in outpatient
  • Chronically immobilized patients
  • Long travel
  • Asymptomatic thrombophilia
  • Non-hospitalized subjects
• Non orthopedic surgical patients
  • General and abdominal pelvic surgeries
  • Cardiac surgery
  • Thoracic surgery
  • Craniotomy
  • Spinal surgery
  • Trauma
• Orthopedic surgery
  • Major orthopedic surgery
  • Isolated lower leg injury
  • 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

Variable	Score
Active cancer	3
Previous VTE	3
Decreased mobility	3
Thrombophilia	3
Previous trauma or surgery within that last month	2
Age≥ 70	1
Heart and/or respiratory failure	1
Ischemic stroke or acute myocardial infarction	1
Acute rheumatologic disorder and/or acute infection	1
Obesity	1
Hormonal therapy	1

IMPROVE Predictive Score for VTE

Calculation of the IMPROVE Predictive Score

Variable	Score
Prior episode of VTE	3
Thrombophilia	3
Malignancy	1
Age more than 60 years	1

Interpretation of the IMPROVE Predictive Score

Score	Predicted VTE risk through 3 months
0	0.5%
1	1.0%
2	1.7%
3	3.1%
4	5.4%
5-8	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. Approximately, 2/3 of medically-ill hospitalized patients are considered at low risk when stratified by IMPROVE-score.

Calculation of the IMPROVE Associative Score

Variable	Score
Prior episode of VTE	3
Thrombophilia	2
Paralysis of the lower extremity during the hospitalization	2
Current malignancy	2
Immobilization for at least 7 days	1
ICU or CCU admission	1
Age more than 60 years	1

Interpretation of the IMPROVE Associative Score

Score	Risk	Predicted VTE risk through 3 months (derivation study)		Predicted VTE risk through 3 months (validation study - VTE-VALOURR)
0	Low	0.4%	0.5%	0.7%	0.20%
1		0.6%		0.8%
2	Moderate	1.0%	1.3%	1.4%	1.0%
3		1.7%		1.9%
4	High	2.9%	4.7%	4.2%	4.2%
5-10		7.2%		7% to 100% (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:

• Score ≥7: Elevated risk of bleeding
• Score <7: Not elevated risk of bleeding

Variable	Score
Active gastric or duodenal ulcer	4.5
Prior bleeding within the last 3 months	4
Thrombocytopenia (<50x109/L)	4
Age ≥ 85 years	3.5
Liver failure (INR>1.5)	2.5
Severe kidney failure (GFR< 30 mL/min/m2)	2.5
Admission to ICU or CCU	2.5
Central venous catheter	2
Rheumatic disease	2
Active malignancy	2
Age: 40-84 years	1.5
Male	1
Moderate kidney failure (GFR: 30-59 mL/min/m2)	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.

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

What is the risk of thrombosis in the acutely ill patient?

High

Low

Is the patient bleeding or at high risk of bleeding?

No VTE prophylaxis

Yes

No

Mechanical VTE prophylaxis For the period of immobilization or hospital stay only ❑ Graduated compression stocking ❑ Intermittent pneumatic compression

Pharmacological VTE prophylaxis For extended period (beyond hospital stay) ❑ Betrixaban 160 mg PO Day 1 then 80 mg OD for 35 to 42 days For the period of immobilization or hospital stay only ❑ LMWH ❑ LDUH, BID ❑ LDUH, TID ❑ Fondaparinux

Did the bleeding or bleeding risk subside AND the patient is still at increased risk of thrombosis?

Yes

No

❑ Substitute mechanical prophylaxis by pharmacological prophylaxis

❑ Continue mechanical prophylaxis

Evidence of Benefit for Hospitalized Acutely Ill Medical Patients

The Cochrane Collaboration found in 2014 that heparin:

• 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:

• In 1 trial of 3706 patients, anticoagulation reduced the relative risk of proximal DVT (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.

Abbreviations: LDUH: low dose unfractionated heparin; LMWH: low molecular weight heparin; VTE: Venous thromboembolism

Is the critically ill patient bleeding or at risk for major bleeding?

Yes

No

Mechanical VTE prophylaxis ❑ Graduated compression stocking ❑ Intermittent pneumatic compression

Pharmacological VTE prophylaxis For extended period (beyond hospital stay) ❑ Betrixaban 160 mg PO Day 1 then 80 mg OD for 35 to 42 days For the period of immobilization or hospital stay only ❑ LMWH ❑ LDUH

Did the bleeding or bleeding risk subside?

Yes

No

❑ Substitute mechanical prophylaxis by pharmacological prophylaxis

❑ Continue mechanical prophylaxis

Cancer in Outpatient

Shown below is an algorithm depicting VTE prophylaxis among cancer patients. Note that, cancer patients with indwelling central venous catheters do not require VTE prophylaxis with neither low molecular weight heparin, low dose unfractionated heparin or vitamin K antagonists.

Abbreviations: LDUH: low dose unfractionated heparin; LMWH: low molecular weight heparin; VTE: Venous thromboembolism

❑ Does the patient have a solid tumor AND ❑ Additional risk factors for VTE? ❑ Previous VTE ❑ Hormonal therapy ❑ Immobilization ❑ Angiogenesis inhibitors ❑ Thalidomide ❑ Lenalidomide

Yes

No

Pharmacological VTE prophylaxis ❑ LMWH ❑ LDUH

❑ No VTE prophylaxis

Chronically Immobilized Patients

No VTE prophylaxis is recommended among subjects who are chronically immobilized either at home or at a nursing home.

Long Travel

Main article: 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.

Does the patient has any of the following that increase the risk of VTE? ❑ Prior VTE episode ❑ Recent trauma ❑ Recent surgery ❑ Active cancer ❑ Advanced age ❑ Immobility ❑ Severe obesity ❑ Estrogen intake ❑ Thrombophilia

Yes

No

Recommend VTE preventive measures: ❑ Calf muscle exercise ❑ Frequent ambulation ❑ To sit in an aisle seat ❑ Graduated compression stockings below the knee (pressure: 15-30 mmHg) ❑ No pharmacological VTE prophylaxis

❑ No preventive measures are required

Asymptomatic Thrombophilia

VTE prophylaxis is not recommended among subjects with asymptomatic thrombophilia.

Lifestyle Modifications

Lifestyle modifications among subjects at elevated risk of VTE might be helpful to prevent thrombosis, they include:

1. Obesity
2. Inactivity
3. Cigarette smoking
4. Dehydration
5. 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.

Abbreviations: LDUH: low dose unfractionated heparin; LMWH: low molecular weight heparin; UH: unfractionated heparin; VTE: venous thromboembolism

Assess the risk of VTE

Very low <0.5% OR Rogers score <7 OR Caprini score=0

Low ~ 1.5% OR Rogers score 7-10 OR Caprini score 1-2

Moderate ~ 3% OR Rogers score >10 OR Caprini score 3-4

High ~ 6% OR Caprini score ≥5

❑ Early ambulation ❑ No mechanical VTE prophylaxis ❑ No pharmacological VTE prophylaxis

❑ Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred)

Is the patient at high risk of bleeding OR Will bleeding cause severe consequences?

Is the patient at high risk of bleeding OR Will bleeding cause severe consequences?

No

Yes

No

Yes

❑ LMWH OR ❑ LDUH OR ❑ Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred)

❑ Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred)

Are LMWH or UH contraindicated?

❑ Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred)

No

Yes

Does the patient have cancer?

❑ Low dose aspirin OR ❑ Fondaparinux OR ❑ Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred)

No

Yes

Pharmacological VTE prophylaxis ❑ LMWH OR ❑ LDUH PLUS Mechanical VTE prophylaxis ❑ Elastic stockings ❑ Intermittent pneumatic compression

Pharmacological VTE prophylaxis ❑ Extended treatment with LMWH for 4 weeks PLUS Mechanical VTE prophylaxis ❑ Elastic stockings ❑ Intermittent pneumatic compression

Cardiac Surgery

Abbreviations: LDUH: low dose unfractionated heparin; LMWH: low molecular weight heparin; VTE: venous thromboembolism

Is the postoperative period prolonged by one or more non hemorrhagic surgical complications?

Yes

No (Uncomplicated post-op period)

Pharmacological VTE prophylaxis ❑ LDUH OR ❑ LMWH PLUS Mechanical VTE prophylaxis

Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred)

Thoracic Surgery

Abbreviations: LDUH: low dose unfractionated heparin; LMWH: low molecular weight heparin; VTE: venous thromboembolism

Is the patient undergoing ANY of the following surgeries that are associated with a high risk of VTE? ❑ Pulmonary resection ❑ Pneumonectomy ❑ Extrapleural pneumonectomy ❑ Esophagectomy

Yes

No

Patient is at HIGH risk of VTE

Patient is at MODERATE risk for VTE

Is the patient at high risk for major bleeding?

Is the patient at high risk for major bleeding?

No

Yes

No

Yes

Pharmacological VTE prophylaxis ❑ LDUH OR ❑ LMWH PLUS Mechanical VTE prophylaxis ❑ Elastic stocking ❑ Intermittent pneumatic compression

Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred) Pharmacological VTE prophylaxis When the risk of bleeding subsides ❑ LDUH OR ❑ LMWH

❑ LDUH OR ❑ LMWH OR ❑ Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred)

Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred) Pharmacological VTE prophylaxis When the risk of bleeding subsides ❑ LDUH OR ❑ LMWH

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.

Is the patient undergoing craniotomy for a malignancy?

Yes

No

Very high risk of VTE (≥ 10%)

High risk of VTE (~ 5%)

Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred) PLUS Pharmacological VTE prophylaxis when the risk of bleeding subsides

Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred)

Spinal Surgery

Is the patient undergoing spinal surgery for malignancy OR undergoing surgery with a combined anterior-posterior approach?

Yes

No

High risk for VTE

Low risk for VTE

Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred) PLUS Pharmacological VTE prophylaxis when the risk of bleeding subsides

Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred)

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.

Abbreviations: LDUH: low dose unfractionated heparin; LMWH: low molecular weight heparin; VTE: venous thromboembolism

Does the patient who has a major trauma have any contraindications for LDUH or LMWH?

No

Yes

Pharmacological VTE prophylaxis ❑ LDUH OR ❑ LMWH PLUS Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred)

Mechanical VTE prophylaxis (Intermittent pneumatic compression is preferred) PLUS Pharmacological VTE prophylaxis when the risk of bleeding subsides

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.

Abbreviations: LDUH: low dose unfractionated heparin; LMWH: low molecular weight heparin; VKA: Vitamin K antagonist; VTE: venous thromboembolism

What is the risk of bleeding of the patient undergoing the major orthopedic surgery?

High

Low

❑ Intermittent pneumatic compression

What is the type of the orthopedic surgery?

Total hip arthroplasty OR Total knee arthroplasty

Hip fracture surgery

Pharmacological VTE prophylaxis Begin at least 12 hours before and 12 hours after the surgery Administer for at least 14 days Extend the therapy to 35 days as outpatient Choose ONE of the following: ❑ LMWH (first line) ❑ Fondaparinux ❑ Apixaban ❑ Dabigatran ❑ Rivaroxaban ❑ LDUH ❑ VKA ❑ Aspirin AND/OR Intermittent pneumatic compression device

Pharmacological VTE prophylaxis Begin at least 12 hours before and 12 hours after the surgery Administer for at least 14 days Extend the therapy to 35 days as outpatient Choose ONE of the following: ❑ LMWH (first line) ❑ Fondaparinux ❑ LDUH ❑ VKA ❑ Aspirin AND/OR Intermittent pneumatic compression device

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:

• 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.

Knee Arthroscopy

VTE prophylaxis is not recommended among patients who undergo knee arthroscopy and who have no previous VTE episodes.

2012 American College of Chest Physicians Evidence-Based Clinical Practice Guidelines: Recommendations for Prevention of VTE in Nonorthopedic Surgical Patients (DO NOT EDIT)

General Surgery, GI surgery, Urological surgery and Gynecologic surgery, Bariatric surgery, Vascular surgery, and Plastic and Reconstructive surgery (DO NOT EDIT)

Grade 1

"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 (Level of evidence B)."

"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 (Level of evidence B) or LDUH (Level of evidence B) over no prophylaxis. "

"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 (Level of evidence B)."

Grade 2

"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.(Level of evidence C) "

"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 (Level of evidence C). "

"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) (Level of evidence B), low-dose unfractionated heparin (LDUH) (Level of evidence B) , or mechanical prophylaxis, preferably with IPC (Level of evidence C) , over no prophylaxis. "

"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 (Level of evidence C) . "

"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 (Level of evidence C). "

"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 (Level of evidence C). "

"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 (Level of evidence C) , fondaparinux (Level of evidence C) , or mechanical prophylaxis, preferably with IPC (Level of evidence C) , over no prophylaxis. "

"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 (Level of evidence C). "

"9. For general and abdominal-pelvic surgery patients, we suggest that periodic surveillance with venous compression ultrasound (VCU) should not be performed (Level of evidence C) . "

Recommendations for Prevention of VTE in Cardiac Surgery Patients (DO NOT EDIT)

Grade 2

"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 (Level of evidence C).

"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 (Level of evidence C).

Recommendations for Prevention of VTE in Thoracic Surgery Patients (DO NOT EDIT)

Grade 1

"1. For thoracic surgery patients at high risk for VTE who are not at high risk for perioperative bleeding, we suggest LDUH (Level of evidence B) or LMWH (Level of evidence B)".

Grade 2

"1. For thoracic surgery patients at moderate risk for VTE who are not at high risk for perioperative bleeding, we suggest LDUH (Level of evidence B), LMWH (Level of evidence B), or mechanical prophylaxis with optimally applied IPC (Level of evidence C) over no prophylaxis."

"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 (Level of evidence C)."

"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 (Level of evidence C)."

Recommendations for Prevention of VTE in Patients undergoing Craniotomy (DO NOT EDIT)

Grade 2

"1. For craniotomy patients, we suggest that mechanical prophylaxis, preferably with IPC, be used over no prophylaxis (Level of evidence B) or pharmacologic prophylaxis (Level of evidence C). "

"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 (Level of evidence C). "

Recommendations for Prevention of VTE in Spinal Surgery Patients (DO NOT EDIT)

Grade 2

"1. For patients undergoing spinal surgery, we suggest mechanical prophylaxis, preferably with IPC, over no prophylaxis (Level of evidence C), unfractionated heparin (Level of evidence C), or LMWH (Level of evidence C)."

"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 (Level of evidence C)."

Recommendations for Prevention of VTE in Major Trauma Patients (DO NOT EDIT)

Grade 2

"1. For major trauma patients, we suggest use of LDUH (Level of evidence C), LMWH (Level of evidence C), or mechanical prophylaxis, preferably with IPC (Level of evidence C), over no prophylaxis."

"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 (Level of evidence C) when not contraindicated by lower extremity injury."

"3. For major trauma patients in whom LMWH and LDUH are contraindicated, we suggest mechanical prophylaxis, preferably with IPC, over no prophylaxis (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 (Level of evidence C)."

"4. For major trauma patients, we suggest that an IVC filter should not be used for primary VTE prevention (Level of evidence C)."

"5. For major trauma patients, we suggest that periodic surveillance with VCU should not be performed (Level of evidence C)."

2012 American College of Chest Physicians Evidence-Based Clinical Practice Guidelines: Recommendations for Prevention of VTE in Orthopedic Surgery Patients (DO NOT EDIT)

Recommendations for Prevention of VTE in Patients Undergoing Major Orthopedic Surgery: THA, TKA, HFS (DO NOT EDIT)

Grade 1

"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 Level of evidence B), or an inter- mittent pneumatic compression device (IPCD) (Level of evidence C). "

"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 (Level of evidence C) ."

"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 (Level of evidence B)."

"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 Level of evidence B).

"5. For asymptomatic patients following major orthopedic surgery, we recommend against Doppler (or duplex) ultrasound (DUS) screening before hospital discharge (Level of evidence B)."

Grade 2

"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 Level of evidence B) , adjusted-dose VKA, or aspirin (all of Level of evidence C)."

"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 (Level of evidence B) , adjusted-dose VKA, or aspirin (all of Level of evidence C)."

"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 (Level of evidence B)."

"4. In patients undergoing major orthopedic surgery, we suggest using dual prophylaxis with an antithrombotic agent and an IPCD during the hospital stay (Level of evidence C)."

"5. In patients undergoing major orthopedic surgery and increased risk of bleeding, we suggest using an IPCD or no prophylaxis rather than pharmacologic treatment (Level of evidence C)."

"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 (Level of evidence C) ."

Recommendations for Prevention of VTE in Isolated Lower-Leg Injuries Distal to the Knee (DO NOT EDIT)

Grade 2

"1. We suggest no prophylaxis rather than pharmacologic thromboprophylaxis in patients with isolated lower-leg injuries requiring leg immobilization (Level of evidence C)."

Recommendations for Prevention of VTE in patients undergoing Knee Arthroscopy (DO NOT EDIT)

Grade 2

"1. For patients undergoing knee arthroscopy without a history of prior VTE, we suggest no thromboprophylaxis rather than prophylaxis (Level of evidence B)."

2012 American College of Chest Physicians Evidence-Based Clinical Practice Guidelines: Recommendations for Prevention of VTE in Nonsurgical Patients (DO NOT EDIT)

Recommendations for Prevention of VTE in Hospitalized Acutely Ill Medical Patients (DO NOT EDIT)

Grade 1

"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)."

"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)."

"3. For acutely ill hospitalized medical patients who are bleeding or at high risk for bleeding, we recommend against anticoagulant thromboprophylaxis (Grade 1B)."

Grade 2

"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)."

"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)."

Recommendations for Prevention of VTE in Critically Ill Patients (DO NOT EDIT)

Grade 2

"1. In critically ill patients, we suggest against routine ultrasound screening for DVT (Level of evidence C)."

"2. For critically ill patients, we suggest using LMWH or LDUH thromboprophylaxis over no prophylaxis (Level of evidence C)."

"3. For critically ill patients who are bleeding, or are at high risk for major bleeding, we suggest mechanical thromboprophylaxis with GCS (Level of evidence C) or IPC (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 (Level of evidence C)."

Recommendations for Prevention of VTE in Patients With Cancer in the Outpatient Setting (DO NOT EDIT)

Grade 1

"1. In outpatients with cancer who have no additional risk factors for VTE, we recommend against the prophylactic use of vitamin K antagonists (Level of evidence B)."

Grade 2

"1. In outpatients with cancer who have no additional risk factors for VTE, we suggest against routine prophylaxis with LMWH or LDUH (Level of evidence B)."

"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 (Level of evidence B)."

"3. In outpatients with cancer and indwelling central venous catheters, we suggest against routine prophylaxis with LMWH or LDUH (Level of evidence B) and suggest against the prophylactic use of vitamin K antagonists (Level of evidence C)."

Recommendations for Prevention of VTE in Chronically Immobilized Outpatients (DO NOT EDIT)

Grade 2

"1. In chronically immobilized persons residing at home or at a nursing home, we suggest against the routine use of thromboprophylaxis (Level of evidence C)".

Recommendations for Thromboprophylaxis during Long-Distance Travel (DO NOT EDIT)

Grade 2

"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 (Level of evidence C). "

"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 (Level of evidence C). For all other long-distance travelers, we suggest against the use of GCS (Level of evidence C). "

"3. For long-distance travelers, we suggest against the use of aspirin or anticoagulants to prevent VTE (Level of evidence C). "

Recommendations for Thromboprophylaxis to Prevent VTE in Asymptomatic Persons With Thrombophilia (DO NOT EDIT)

Grade 1

"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 (Level of evidence C). "