Venous Thromboembolism Flashcards
(33 cards)
What is a VTE?
A thrombus is a clump of platelets, fibrin, red blood cells and white blood cells. These can form in both the arterial and venous circulation. A thrombus, or part of one, that enters the left side of the circulatory system can enter the heart and may result in subsequent blockage in peripheral arteries either in the lower limbs or in the cerebral circulation. The former is known as a deep vein thrombosis (DVT) and the latter may cause a thromboembolic stroke.
If a thrombus, or part of one, enters the right side of the circulatory system it may block part of the pulmonary arterial circulation. This is known as a pulmonary embolism (PE).
the common presenting symptoms of a DVT and a PE.
Important components for the clinical diagnosis of VTE include risk factors such as immobilization, presence of cancer, confinement to bed, previous major surgery, prior VTE and - specific for DVT - whole limb enlargement, one-sided calf enlargement and dilatation of superficial veins. Additional items specific for PE include tachycardia, dyspnea chest pain and hemoptysis
Do not offer anti-embolism stockings to people who have:
suspected or proven peripheral arterial disease
peripheral arterial bypass grafting
peripheral neuropathy or other causes of sensory impairment
any local conditions in which anti-embolism stockings may cause damage – for example, fragile ‘tissue paper’ skin, dermatitis, gangrene or recent skin graft
known allergy to material of manufacture
severe leg oedema
major limb deformity or unusual leg size or shape preventing correct fit.
Use caution and clinical judgement when applying anti-embolism stockings over venous ulcers or wounds.
Elective knee replacement
Offer VTE prophylaxis to people undergoing elective knee replacement surgery whose VTE risk outweighs their risk of bleeding. Choose any one of:
- aspirin (75 or 150 mg) for 14 days.
- LMWH for 14 days combined with anti-embolism stockings until discharge.
- Rivaroxaban, within its marketing authorisation, is recommended as an option for the prevention of venous thromboembolism in adults having elective total hip replacement surgery or elective total knee replacement surgery.
how can people reduce their risk of VTE
keeping well hydrated and, if possible, exercising and becoming more mobile
Acutely ill medical patients
Offer pharmacological VTE prophylaxis for a minimum of 7 days to acutely ill medical patients whose risk of VTE outweighs their risk of bleeding:
- Use LMWH as first-line treatment.
- If LMWH is contraindicated, use fondaparinux sodium
Define PE
If it dislodges and travels to the lungs, it is called a pulmonary embolism, which in some cases can be fatal.
Assessing the risk of VTE and bleeding - On admission, identify all patients at increased risk of VTE. ♦ Medical patients are at increased risk if:
- Mobility is significantly reduced for ≥3 days, OR
- they are expected to have ongoing reduced mobility and
have one or more risk factors for VTE
Assessing the risk of VTE and bleeding - On admission, identify all patients at increased risk of VTE. ♦ Surgical and trauma patients are at increased risk if one or more of the following applies:
- surgical procedure with a total intravenous anaesthetic
and surgical time >90 minutes, or 60 minutes if the surgery involves the pelvis or lower limb, - acute surgical admission with inflammatory or intraabdominal condition,
- significant reduction in mobility,
- one or more risk factors for VTE
Assessing the risk of VTE and bleeding - On admission, identify all patients at increased risk of VTE.
♦ Assess all patients for risk of bleeding before giving
pharmacological VTE prophylaxis.
- Do NOT give prophylaxis to patients with any risk factor
for bleeding, unless risk of VTE outweighs
bleeding risk.
♦ Reassess risk of bleeding and VTE within 24 hours of
admission and if clinical situation changes to ensure:
- the methods of prophylaxis being used are suitable and
are being used correctly,
- any adverse effects are identified.
Reducing the risk of VTE
Mobilise the patient as soon as possible.
♦ Give pharmacological prophylaxis if appropriate;
- start treatment as soon as risk has been assessed,
- continue until the patient’s mobility is no longer reduced
and they are not at risk of VTE.
Types of VTE prophylaxis
Mechanical prophylaxis
♦ anti-embolism stockings (thigh or knee length).
♦ foot impulse devices.
♦ intermittent pneumatic compression devices (thigh or knee length).
Pharmacological prophylaxis ♦ LMWH ♦ UFH – for patients with renal failure. ♦ Fondaparinux sodium. Also consider dabigatran or rivaroxaban for prophylaxis after hip or knee replacement surgery.
Anti-embolism stockings
♦ Measure legs and use correct sized stockings.
♦ Use stockings that provide graduated compressi
produce a calf pressure of 14-15mmHg.
♦ Patients should wear stockings continuously whilst mobility is reduced with removal daily for hygiene purposes.
Cautions
Anaesthesia
♦ For considerations around anaesthesia
Patients taking antiplatelet or anticoagulant therapy
♦ Assess the risks and benefits of stopping antiplatelet
therapy one week prior to elective surgery.
If at risk of VTE, consider risk of bleeding and comorbidities
- if the risk of VTE outweighs the risk of bleeding: give
additional pharmacological prophylaxis.
if the risk of bleeding outweighs the risk of VTE: use
mechanical prophylaxis.
o NOT give pharmacological or mechanical prophylaxis:
- to patients already taking vitamin K antagonists
(e.g. warfarin), providing these are continued and kept in
therapeutic range,
to patients already receiving full anticoagulant therapy.
Do NOT regard aspirin or other antiplatelet agents as
adequate prophylaxis for VTE.
Patients taking oral contraceptives or HRT
♦ Advise women to stop taking these 4 weeks prior to
elective surgery.
Risk factors for VTE
♦ Active cancer or cancer treatment ♦ Age >60 years ♦ Admission to critical care ♦ Dehydration ♦ Known thrombophilia ♦ Obesity (BMI >30kg/m2) ♦ One or more medical comorbidities ♦ Personal history or first degree relative with history of VTE ♦ Use of hormone replacement therapy ♦ Use of oestrogen containing contraceptives ♦ Varicose veins with phlebitis ♦ Pregnancy or up to 6 weeks post-partum
Risk factors for bleeding
♦ Active bleeding
♦ Acquired bleeding disorder such as acute liver failure
♦ Concurrent use of anticoagulants known to increase risk of bleeding (such as warfarin with INR >2)
♦ Lumbar puncture, epidural or spinal anaesthesia within the previous 4 hours or expected within the next 12 hours
♦ Acute stroke
♦ Thrombocytopenia
♦ Uncontrolled systolic hypertension (≥230/120mmHg)
♦ Untreated inherited bleeding disorder
Prescribing - Choice of pharmacological agent for VTE prophylaxis should be based on local policies and individual patient factors including clinical conditions and patient preferences
LMWH
♦ There are four available LMWH preparations.
♦ Not all have marketing authorisation for VTE prophylaxis in medical patients. See SPC for individual LMWH.
UFH
♦ Use in patients with renal impairment.
Fondaparinux
♦ Administer once daily as a subcutaneous injection.
Oral anticoagulants
♦ Dabigatran and rivaroxaban are only licensed for
prophylaxis after hip and knee replacement surgery.
Counselling
Before starting VTE prophylaxis provide information about:
♦ the risk and consequences of VTE,
♦ the importance of prophylaxis and correct use,
♦ possible adverse effects,
♦ how to reduce risk of VTE e.g. maintaining adequate hydration.
At discharge
Inform GP that the patient has been discharged with VTE
prophylaxis.
Provide information about:
♦ signs and symptoms of DVT and PE,
♦ duration of use of VTE prophylaxis and the importance of using this correctly,
♦ who to contact if there are any problems using prophylaxis, or if a DVT, PE or another adverse event is suspected.
Mechanical and Pharmacological Prophylaxis for Speciality - General Medical
Mechanical Prophylaxis - Consider if pharmacological
prophylaxis contraindicated
Pharmacological Prophylaxis - Fondaparinux, LMWH (or UFH). Continue until patient no longer at increased
risk of VTE.
Mechanical and Pharmacological Prophylaxis for Speciality - Cancer
Mechanical Prophylaxis - Do not routinely offer – see
full guidelines.
Pharmacological Prophylaxis - Fondaparinux, LMWH (or UFH). Continue until patient no longer at increased
risk of VTE.
Mechanical and Pharmacological Prophylaxis for Speciality - Palliative care
Mechanical Prophylaxis - Do not routinely offer – see
full guidelines.
Pharmacological Prophylaxis - Fondaparinux, LMWH (or UFH) if patient has reversible acute pathology. Review need for VTE prophylaxis daily.
Mechanical and Pharmacological Prophylaxis for Speciality - Central venous catheter
Mechanical Prophylaxis - Do not routinely offer
Pharmacological Prophylaxis - LMWH (or UFH). Reassess within 24 hrs and whenever clinical situation changes.
Mechanical and Pharmacological Prophylaxis for Speciality - Stroke
Mechanical Prophylaxis - Do NOT use anti-embolism stockings.
Pharmacological Prophylaxis - LMWH (or UFH) if haemorrhagic stroke excluded and bleeding risk low.
Continue until patient’s condition is stable.
Mechanical and Pharmacological Prophylaxis for Speciality - Cardiac, Gynaecological, Thoracic, Urological, Neurological, Vascular
Mechanical Prophylaxis - Start on admission if VTE risk
increased.
Pharmacological Prophylaxis - If risk of major bleeding low add LMWH (or UFH). Continue until mobility is no longer significantly reduced - approximately 5 to 7 days. If the patient has had major cancer surgery in the abdomen or pelvis, continue for 28 days after surgery.
