Venous thromboembolism prevention resident survival guide

Venous Thromboembolism Prevention Resident Survival Guide Microchapters
Non Surgical Patients
Non Orthopedic Patients
Orthopedic Patients

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rim Halaby, M.D. [2]

Overview

Venous thromboembolism (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 in Non Surgical Patients

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 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

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.

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	Predicted VTE risk through 3 months
0	0.4%
1	0.6%
2	1.0%
3	1.7%
4	2.9%
5-10	7.2%

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

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 ❑ 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

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.

VTE Prevention in Non Orthopedic 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

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

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

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 inferioir vena cava filter as VTE prophylaxis or screening with a compression ultrasound for VTE.

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 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.

References