Venous Thrombo-embolism Prevention Flashcards Preview

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Flashcards in Venous Thrombo-embolism Prevention Deck (52)
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What is a venous thromboembolism

- Blood clot that starts in the calf- they may remain localise or they may go across the vein to occlude it and grow proximally
- can embolism and move around and spread to other areas of the body


What are the consequences of venous thromboembolism

- PE
- Post thrombotic syndrome
- leg ulcers


What is the 3rd most common cause of cardiovascular death



what is the second most common cause of death in cancer and commonest cause of preventable hospital related death and most common cause of maternal mortality



Why is VTE important

Common - 1 in 1000 per year
- treatments effective but significant risks - major and fatal bleeding


If you get a VTE what are you at risk of in the future

- Post thrombotic syndrome
- Chronic thromboembolic pulmonary hypertension (CTEPH)


What are most death from PE due to

- diagnostic failure rather than treatment failure - most patients die as the diagnosis is not suspected


What is your chances of dying from a DVT and PE

VTE – natural history
30-day case fatality PE vs DVT
– 7%v2%(OR3.8, 95% CI 1.6-9.2)
– ≈ 50% of above deaths from PE (approx. 4% v 1%)


What is pulmonary embolism the most common cause of

- Most common cause of missed or delayed diagnosis


After you stop anticoagulants after 3 months what is the risk of developing another VTE

- Overall 5% per year initially
• 20% at 5 years
• 30% at 10 years
– Higher (≈10% in first year) if unprovoked than if provoked by temporary risk factor


What is post thrombotic sydnrome

- complicates 40% of DVT cases
- develops within 2 years of DVT diagnosis
- variable severity
- reduced quality of life
- cost to individual and society


What are the symptoms of post-thrombotic syndrome

- pain
- swelling
- skin induration/discolouration
- ulceration


what 3 risk factors lead to VTE/PE development
- virchows triad

- blood flow
- blood coagulability
- vessel wall damage


What are the major risk factors for VTE

• Fracture of hip/pelvis
• Hip or knee replacement surgery
• Major general surgery especially for malignancy
• Major trauma
• Spinal cord injury
• Hospitalisation with acute medical illness


What are the moderate risk factors for VTE

• Previous VTE
• Malignancy/chemotherapy
• Pregnancy and post-partum period
• Combined oc pill or hormone therapy
• Central venous line
• Thrombophilia
Risk factors
• Other medical conditions e.g. nephrotic syndome, inflammatory bowel disease, Behçets syndrome


What are weak but common risk factors for VTE

• Age
• Travel-related thrombosis
• Obesity
• Varicose veins
• Diet
• Smoking
• Air pollution


describe how hospital admission leads to VTE risk

VTE following hospital discharge
Worcester DVT study (2007)
• 74% presented as outpatients
– 37% recent hospitalisation +/- surgery
– 23% recent major surgery +/- hospitalisation – 29% recent cancer diagnosis
– 20% previous VTE diagnosis
– 70% ≥1 VTE risk factors


why do cancer patients have an increased risk of VTE

– Cancer is prothrombotic
– Immobility
– Chemotherapy
– Central venous lines


of patients presenting with unprovoked VTE...

5% have a new cancer diagnosed within 3 years


What is the 2nd leading cause of death in cancer patients



When you are pregnant what increases your risk of developing a VTE

• Obesity
• Maternal age > 35 years
• Caesarean section (especially emergency)


What is trousseau syndrome

- the connection between VTE and cancer


Describe how the risk of VTE change in pregnancy

- mostly level during pregnancy but increases before delivery
- after delivery it massively increases in the first 6 weeks after delivery


What are the NICE guidelines for VTE

- All patients on admission receive an assessment of VTE and bleeding risk using the clinical risk assessment criteria
- patients are offered verbal and written information on VTE prevention as part of the admission process
- patients provided with anti-embolism stockings have them fitted and monitored
- patients are re-assessed within 24 hours of admission for risk of VTE and bleeding
- patients assessed to be at risk of VTE are offered VTE prophylaxis in accordance with NCIE guidelines
- patients are offered verbal and written information on VTE prevention as part of the discharge process
- patients are offered extended VTE prophylaxis


Name thrombosis risk

- Active cancer or cancer treatment
- age over 60
- dehydration
- known thrombophiliais
- obesity
- one or more significant medical co-morbidities - e.g. heart disease, metabolic, endocrine or respiratory pathologies, acute infectious diseases
- personal history or first degree relative with a history of VTE
- use of hormone replacement therapy
- use of oestrogen containing contraceptive therapy
- varicose veins with phlebitis
- pregnancy or less than 6 weeks post partum

admission related
- significantly reduced mobility for 3 days or more
- hip or knee replacemetn
- hip fracture
- total anaesthetic and surgical times greater than 90 minutes
- surgery involving pelvis or lower limb with a total anaesthetic and surgical time greater than 60 minutes
- acute surgical admission with inflammatory or intra-abdominal condition
- critical care admission
- surgery with significant reduction in mobility


Name the bleeding risks

Patient related
- active bleeding
- acquired bleeding disorders
- concurrent use of anticoagulatns known to increase the risk of bleeding
- acute stroke
- thrombocytopaenia
- uncontrolled systolic hypertension - 230/120 or higher
- untreated inherited bleeding disorder

Admission related
- neurosurgery, spinal surgery or eye surgery
- other procedure with high bleeding risk
- lumbar puncture/epidural/spinal anaesthesia expected within the next 12 hours
- lumbar puncture/epidural/spinal anaesthesia within the previous 4 hours


Name the mechanical methods of thromboprophylaxis

- Anti embolism stockings
- intermittent pneumatic compression


Name the pharmacological methods of thromboprophyalxis

– Unfractionated heparin
– Low molecular weight heparin
– Fondaparinux
– New direct oral anticoagulants (DOACs)


describe parenteral thromboprophylaxis

– Unfractionated heparin 5000 u sc bd or tds

– Low molecular weight heparin
• Enoxaparin 40 mg sc od
• Dalteparin 5000 u sc od
• Tinzaparin 4500 u sc od

– Fondaparinux - synthetic pentasaccharide - 2.5 mg sc od


describe oral thromboprophylaxis

– Direct thrombin inhibitor
• Dabigatran

– Factor Xa inhibitor
• Rivaroxaban
• Apixaban
• Edoxaban (not yet licensed for VTE prevention)