Venous Thromboembolism (DVT and PE)

Question 1

Complications of VTE?

Answer 1

• PE (embolus RV)

- Stroke (embolus –> LV due to ASD)

Question 2

Risk factors for VTE

Answer 2

• Prolonged immobility (3+ days)
• Oestrogen hormone therapy
• Thrombophilia
• Recent surgery
• Malignancy (active, within 6 months palliative)
• SLE
• Polycythemia
• Obesity
• Age > 50 years

Question 3

Types of VTE prophylaxis?

For surgical patients, what do you give?

For medical patients what VTE prophylaxis do u give?

For pregnant women what do you give?

Answer 3

Mechanical 
- Anti-embolic compression socks 
- Intermittent pneumatic compression device 
Pharmacological 
- Fondaparinux Sodium 
- LMWH
- UFH (renal impaired)

Surgical

> Abdominal, thoracic, cardiac, elective spinal, ENT, maxofacial

• -> Anti-embolic compression socks
• -> Fondaparinux sodium if cardiac, abdominal, bariatric, thoracic surgeries or fragility fractures of pelvis/hip/femur or leg immobilisation

> Orthopaedic or general surgery
–> LMWH –> if renally impaired, give UFH

Elective hip surgery

• -> LMWH for 10 days, followed by aspirin for 28 days
• -> LMWH and anti-embolic socks for 28 days
• -> DOACs

Elective knee surgery

• -> aspirin for 14 days
• -> or LMWH for 14 days
• -> or DOACs

Medical patients

• LMWH heparin or fondaparinux sodium for all patients apart from renally impaired patients who are given UFH
• stroke patients –> intermittent pneumatic compression device.

Pregnant women (not currently in labour, postpartum in patients who have had a miscarriage or TOP)

• LMWH until discharged/VTE risk is reduced to normal
• If risk of immobility, use intermittent pneumatic compression device

Question 4

What are the signs and symptoms of DVT?

Answer 4

Unilateral

• Leg tenderness
• Swelling (3cm > asymptomatic side)
• Colour changes
• Distension of the superficial veins

Question 5

Ix for DVT?

Management for DVT?

Length of therapy?

Answer 5

Two level DVT criteria - see below

Criteria
> Active cancer (treatment ongoing, within 6 months, palliative) ==> 1 point
> Paralysis, paresis, or recent plaster immobilisation of the lower extremeties ==> 1 point
> Recently bed ridden for 3 days or recent surgery within the last 4 weeks == 1 point
> Pitting oedema ==> 1 point
> Entire leg swollen ==> 1 point
> Affected calf 3cm+ greater than non-affected calf ==> 1 point
> Collateral superficial veins ==> 1 point
> Previous DVT/PE diagnosis ==> 1 point
> An alternative diagnosis just as likely ==> - 2 points

Ix
Well’s score: 2 or higher

Do US of leg within 4 hours
- Positive –> diagnose DVT
- Negative –> do d-dimer
> if positive –> stop anti-coagulant
and repeat 1 week after
> if negative –> stop anti-coagulant,
consider alternative Dx

Wells score <2
Do D dimer
> positive –> do ultrasound of leg within 4 hours
> positive –> diagnose DVT
> negative –> stop anti-coagulant +
repeat US 1 week after
> Negative –> consider alternative diagnosis + stop anticoagulant therapy

Management
- First line = DOAC (apixaban or rivaroxaban) unless contraindicated. If contraindicated, then consider LMWH followed by dabigatran or enoxaban or warfarin

• If patient has active cancer –> DOAC
• if patient has renal impairment or anti-phospholipid syndrome –> LMWH + vit k antagonist

Length of therapy

• If provoked DVT (cause known) –> 3 months
• If DVT unprovoked (cause unknown or malignancy) –> 6 months

Question 6

What are the signs and symptoms of PE?

Answer 6

Signs/symptoms

• Tachycardia
• Tachypnea
• Cough with/without blood (haemoptysis)
• Pleuritic chest pain (sharp chest pain, exacerbated by breathing)
• SOB
• Hypoxia
• Low grade fever
• Haemodynamically unstable e.g. hypotension

Classical PE in text books - 10%
- Haemotypsis, dyspnea, pleuritic chest pain

Most cases present with varied cardioresp symptomology

PIOPED study found the following signs/symptoms to be most associated with PE

• Tachycardia
• Crackles
• Tachypnea
• ECG changes –> sinus tachycardia most common, but in 20% of patients, S1Q3T3 is a classical finding on leads 1 and 3 whereby there is elevation of S wave in lead 1, enlarged Q wave on lead 3 and an inverted T wave in lead 3.
• Fever (>37.8)

Patients may also present with signs and symptoms of DVT as well e.g. unilateral leg swelling and tenderness

Question 7

Ix for PE?

When do you consider V/Q scan?

What should you consider when carrying out d dimer?

What ECG findings are typical for PE?

What CXR findings would you see?

Management for PE?

Answer 7

Ix to consider

• PERC
• Well’s criteria
• ABG
• CTPA or V/Q scan
• D-dimer
• ECG
• CXR

Ix for PE

If low chance for PE (<15%) –> pulmonary embolism rule out criteria (PERC).

PERC - PE risk is less than 2% if all of the below are absent.

• age = 50+
• HR > 100bpm
• SpO2 < 94%
• Haemoptysis
• Previous DVT/PE diagnosis
• Unilateral leg swelling
• Oestrogen (HRT, contraception)

If chance of PE> 15%, apply the two level Well’s criteria.

• Signs/symptoms of DVT e.g. unilateral leg swelling with palpitation of veins –> 3 points
• Other diagnosis unlikely –> 3 points
• Tachycardia –> 1.5 points
• Immobility (3+ days) or recent surgery –> 1.5 points
• Previous DVT/PE diagnosis –> 1.5 points
• Malignancy - 1 point
• Haemoptysis - 1 point

Well’s score > 4 –> PE likely
Well’s score < 4 –> PE unlikely

If Well’s score > 4

• Carry out CTPA
  
  • -> if positive –> diagnose DVT
  • -> if negative –> carry out an ultrasound of the proximal leg vein if they have suspected DVT

If Well’s score < 4

• • carry out D dimer
  • -> positive –> carry out a CTPA urgently.
    - -> if CTPA positive –> Dx
    - -> if CTPA negative –> possible another scan?

–> negative –> alternative diagnosis and stop anticoagulant.

Others
V/Q scan
- consider if patient has renal impairment

D dimer
- age adjusted for patients > 50 yrs

ECG
- Sinus tachycardia - most common finding
- Classical PE –> S1Q3T3
> Elevated S wave in lead 1
> Elevated Q wave in lead 3
> Inverted T wave in lead 3
- Right bundle branch block or right axis deviation seen in PE patients

CXR

• Normal in most patients
• Some patients may see wedge shaped opacity

Management
- Outpatients
> Pulmonary embolism index score can be used to see if patient can be treated as an outpatient (is patient haemodynanically stable, is support available at home and does patient have co-morbidities)

VTE management

• DOAC (apixaban or rivaroxaban) unless contraindicated –> use LMWH followed by dabigatran/enoxaban/warfarin
• If patient has active cancer –> use DOAC unless contraindicated
• If patient has renal impairment/ APS –> use LMWH followed by vit K antagonist

Length of anticoagulation

• Unprovoked PE –> 6 months
• Provked PE - 3 months

HAS-BLED score can be used to assess the risk of bleeding.

Patients with haemodynamic instability
- Patients with massive PE, thrombolysis is recommended as first line if there is circulatory failure e.g. if the patient is experiencing hypotension.

Patients that have repeated PE despite adequate anticoagulant therapy, consider inferior vena cava filters (IVC) which stop clots found in the deep veins of the legs from moving up to the deeper arteries.

Question 8

Contraindications for anti-embolic compression stockings?

Answer 8

When not to wear compression hosiery

• Ischaemia: This is a lack of oxygen in the limbs due to peripheral arterial disease, particularly affecting your legs. This causes pain on walking, known as intermittent claudication. It arises because the arteries supplying the legs have become narrowed or blocked, and the muscles cannot get enough oxygen.
• Peripheral neuropathy: This is damage to the nerves in your hands, arms, feet and legs.
• Congestive heart failure: This arises when the heart muscle becomes weak or stiff and cannot pump blood around the body efficiently. It causes a build – up of fluid – oedema in the legs.
• Diabetes: Peripheral arterial disease and peripheral neuropathy are both complications of diabetes.
• Cellulitis: An infection deep within the skin that causes fluid build-up – oedema.
• Allergies: Some people can be allergic to components used to make compression garments. Skin reactions do occur – Â sometimes these can be solved by using a different brand or type, but if you are allergic to compression garments, wearing them will put you at risk of skin breaks and infection.

Anyone with other conditions that would normally require treatment with compression hosiery needs to be carefully assessed and monitored.

Compression therapy should only be considered if the medical team decides that the benefits of compression will outweigh the risks.

When can compression hosiery be harmful?
-For some people and for some conditions, there are risks to using compression. These risks are:
> Making ischaemia worse: If the limb is already short of oxygen (ischaemia) or is abnormally swollen (oedema), a compression stocking or sleeve will compress the smaller blood vessels near to the surface of the skin, making it more likely that the tissues will be short of oxygen.
> Causing pain: Compression hosiery used as a medical treatment should be made-to-measure. If a compression garment is too tight, this can be very uncomfortable. If you have an underlying condition such as heart failure or cellulitis, your limbs can swell considerably in a short time period.
> Tissue damage: This can occur in the two situations above, and also in someone with peripheral neuropathy, as pain signals may not be noticed because of nerve damage.