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Venous ThromboembolismReducing the Risk

<Name of session> DATE

Objectives• Define venous thromboembolism• Heighten awareness– the impact of VTE– the preventable nature of VTE

• Discuss importance of – VTE risk assessment– appropriate prescribing of prophylaxis– engaging patients

• Demonstrate how to assess VTE risk

Venous Thromboembolism

• VTE = Deep vein thrombosis (DVT) and/or pulmonary embolism (PE)

DVT PEOccurs in deep veins (most commonly in legs and groin)

Occurs after DVT dislodges and travels to the lungs

Can cause long-term issues – ‘post-thrombotic syndrome’ (PTS)

Serious complication which can lead to death

PTS affects 23-60% of DVT patients within 2 years

Lower-extremity DVT has 3% PE-related mortality rate

Patients with PE have 30-60% chance of dying from it

What Causes VTE• Virchow’s Triad = categories of factors

contributing to blood clot formationStasis

Alteration in normal blood flow

Endothelial InjuryInjury or trauma to the

inside of the blood vessel

HypercoagulabilityAlternation in the constitution of blood causing blood to clot

more easily

VIRCHOW’S TRIAD

The Impact of VTE• More than 14,000

Australians develop a VTE per year

• More than 5,000 of them will die as a direct result

• VTE causes 7% of all hospital deaths

VTE causes more deaths than bowel Ca and breast Ca

VTE Risk Factors

VTE Risk FactorsIntrinsic Risk Factors Extrinsic Risk Factors

Age > 60 years Significantly reduced mobility (relative to normal state) due to injury or illness

Obesity (BMI > 30kg/m2) Active malignancy or treatment with chemotherapy

Prior history of VTE Use of HRT or oral contraception

Pregnancy or post-partum Surgical intervention, particularly major orthopaedic surgery or abdominal/pelvic surgery for cancer

Known thrombophilia (including inherited disorders)

Active infection

Varicose veins Inflammatory bowel disease

Hospitalisation• Hospitalisation = ↑ risk of VTE

• ~ 50% of VTE cases occur during or soon after hospitalisation– 24% (surgery)– 22% (medical illness)

• Incidence 100 times greater in hospitalised patients than community residents

Preventing VTE

Preventability• Largely preventable• Shift thinking: complication vs adverse event

VTE Prevention

Risk Assessment

Prescribing Appropriate Prophylaxis

Patient Groups

ALL adult patients

admitted into hospital

Patients discharged from ED with significantly

reduced mobility relative to normal state eg in a cast/boot

following lower leg injury

Pregnant and post-partum

women

Others: Pre-admission for

elective surgery

Assessing Risk• Who should be assessed?

• Assess overall VTE risk vs benefit– Assess clotting risk– Assess bleeding risk

i.e. contraindications to prophylaxis and/or other bleeding risks

• <indicate what tool is available at your facility (State Tool* or Local Tool)>

Assessing Risk

Prescribing Prophylaxis

• Patient at risk + nil C/I = prescribe• Two types of prophylaxis:

1. pharmacological 2. mechanical

• Ensure C/I to both pharmacological and mechanical prophylaxis have been considered

• Evidence-based guidelines

NHMRC Guidelines

Pharmacological Prophylaxis• Anticoagulants• Alter the process of blood

coagulation to prevent VTE formation

http://www.healio.com/orthopedics/hip/news/online/%7Ba0ebf835-ae3d-42df-a9e5-ae55b11e0413%7D/new-oral-anticoagulants-for-thromboprophylaxis-after-total-hip-or-knee-arthroplasty

The coagulation cascade and activity of anticoagulants

Pharmacological Prophylaxis• Main anticoagulants include:

Drug Class Agents

Unfractionated heparin

Unfractionated heparin

Preferred in patients with renal impairment

LMWH EnoxaparinDalteparin

Most commonly used agentsRequire dosage adjustment in renal impairment

Factor Xa inhibitors

ApixabanRivaroxaban

Alternative for prophylaxis in post- hip or knee replacement

Fondaparinux Alternative for prophylaxis in post- hip or knee replacement and hip fracture surgery

Direct thrombin inhibitors

Dabigatran Alternative for prophylaxis in prophylaxis post- hip or knee replacement

Heparinoid Danaparoid Used in heparin-sensitivity or HIT

Pharmacological Prophylaxis• Contraindications may include:

• Other relative contraindications may exist – weigh risk vs benefit

Contraindications

Active bleeding

Thrombocytopenia (platelets < 50 x 109/L)

End stage liver disease (INR > 1.5)

Treatment with therapeutic anticoagulant e.g. warfarin with INR > 2Severe trauma to head or spinal cord, with haemorrhage in last 4 weeks

Mechanical Prophylaxis• Devices that increase blood flow velocity in

leg veins, reducing venous stasis.• They include:

Device

Graduated Compression Stockings (GCS)

Provide graduated compression, which is firmest at the ankle. Used mainly for ambulant patients

Anti-embolic Stocking Standard compression throughout.Used for bedbound or non-ambulant patients

Intermittent Pneumatic Compression Device (IPC)

Inflatable garment wrapped around legs which is inflated by pneumatic pump. Enhances venous return

Foot Impulse Device (FID) Stimulates legs veins to mimic walking and reduce stasis. Used for immobilised patients

Mechanical Prophylaxis• Contraindications may include:

Contraindications

Skin ulceration

Lower leg trauma

Morbid obesity (where correct fitting of stocking cannot be achieved)Massive leg oedema or pulmonary oedema due to CCF

Stroke patients (avoid compression stockings)

Other Ways to Help Prevent VTE

Empowering Patients• Engage your patients

Empower with

Information

VTE risk factors

What you as their Dr are doing to prevent their

development of a VTE

Signs and symptoms

of VTE

What they can do to help prevent a VTE

Questions

For further information:

stopclots@cec.health.nsw.gov.auwww.cec.health.nsw.gov.au