Venous Thromboembolism
Reducing the Risk
<Name of session>
DATE
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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
PE
Occurs 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 formation
Stasis
Alteration in normal blood flow
VIRCHOW’S TRIAD
Endothelial Injury
Injury or trauma to the
inside of the blood vessel
Hypercoagulability
Alternation in the constitution
of blood causing blood to clot
more easily
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 Factors
Intrinsic 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
Risk
Assessment
VTE
Prevention
Prescribing
Appropriate
Prophylaxis
Assessing Risk
• Who should be assessed?
ALL adult
patients
admitted into
hospital
Others: Preadmission for
elective
surgery
Patient
Groups
Pregnant and
post-partum
women
Patients discharged from
ED with significantly
reduced mobility relative
to normal state
eg in a cast/boot
following lower leg
injury
Assessing Risk
• 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)>
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
The coagulation cascade and activity of anticoagulants
http://www.healio.com/orthopedics/hip/news/online/%7Ba0ebf835-ae3d-42dfa9e5-ae55b11e0413%7D/new-oral-anticoagulants-for-thromboprophylaxis-aftertotal-hip-or-knee-arthroplasty
Pharmacological Prophylaxis
• Main anticoagulants include:
Drug Class
Agents
Unfractionated
heparin
Unfractionated
heparin
Preferred in patients with renal impairment
LMWH
Enoxaparin
Dalteparin
Most commonly used agents
Require dosage adjustment in renal impairment
Factor Xa
inhibitors
Apixaban
Rivaroxaban
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 posthip or knee replacement
Heparinoid
Danaparoid
Used in heparin-sensitivity or HIT
Pharmacological Prophylaxis
• Contraindications may include:
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 > 2
Severe trauma to head or spinal cord, with haemorrhage in last
4 weeks
• Other relative contraindications may exist –
weigh risk vs benefit
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
VTE risk factors
What they can do
to help prevent a
VTE
Empower
with
Information
Signs and
symptoms of VTE
What you as their
Dr are doing to
prevent their
development of a
VTE
Questions
For further information:
stopclots@cec.health.nsw.gov.au
www.cec.health.nsw.gov.au