Deep vein thrombosis

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

INITIAL

suspected DVT of the leg

with phlegmasia cerulea dolens

1st line – anticoagulation

Back

1st line –

anticoagulation

If you suspect phlegmasia cerulea dolens (PCD), act quickly because PCD is a life- and limb-threatening emergency; do not wait for the results of investigations to start treatment.[26]

Immediately start anticoagulation with either unfractionated heparin or a low molecular weight heparin such as enoxaparin or dalteparin.[26]

Primary options

heparin: 75 mg/kg intravenously as a loading dose, followed by 18 units/kg/hour intravenous infusion, adjust dose according to aPTT; 5000 units intravenously as a loading dose, followed by 15,000 units subcutaneously every 12 hours, adjust dose according to aPTT

enoxaparin: 1 mg/kg subcutaneously every 12 hours

dalteparin: 100 units/kg subcutaneously every 12 hours, maximum 18,000 units/dose

Plus – immediate referral to a vascular surgeon

Plus – supportive care

without phlegmasia cerulea dolens

1st line – consider interim anticoagulation

Back

1st line –

consider interim anticoagulation

Before starting interim therapeutic anticoagulation for suspected DVT, order baseline blood tests including full blood count, renal and hepatic function, prothrombin time, and activated partial thromboplastin time.[12][26]

However, do not wait for the results of these before starting anticoagulation.[12]
Review the results (and act on these if necessary) within 24 hours of starting anticoagulation.[12]

Practical tip

If D-dimer testing is required, always order this before giving anticoagulation; a false negative D-dimer result can occur if blood is drawn after the patient has been given anticoagulation.[26]

If possible, choose an interim anticoagulant that can be continued if DVT is confirmed.[12] See the No contraindication to anticoagulation treatments under Initiation-phase therapy: confirmed proximal DVT of the leg below for more information about anticoagulation.

Start interim therapeutic anticoagulation (as long as there are no contraindications) if:[12]

The patient is categorised as ‘DVT likely’ (Wells score ≥2) and the result of venous ultrasound is not available within 4 hours
The patient is categorised as ‘DVT unlikely’ (Wells score <2) and:
- The D-dimer level has been taken but the result is not available within 4 hours
  OR
- The D-dimer result is positive, and a venous ultrasound has been arranged with the result available within 24 hours
You suspect DVT clinically in a pregnant patient.[27] Do not wait for the results of imaging.[27]

Stop interim therapeutic anticoagulation if venous ultrasound is negative.[12]

Plus – decide on setting of care

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Plus –

decide on setting of care

Treatment recommended for ALL patients in selected patient group

Most patients with suspected or confirmed DVT can receive treatment at home, rather than in the hospital.[27] Outcomes are at least as good as those achieved with hospitalisation, and improved patient satisfaction.[103] [ ] [Evidence C] However, arrange hospital admission if any of the following apply:

DVT that is best treated with intravenous unfractionated heparin
Suspected or confirmed concomitant pulmonary embolism (PE) requiring admission (e.g., haemodynamically unstable, intermediate-risk PE based on the Pulmonary Embolism Severity Index [PESI] score or the simplified Pulmonary Embolism Severity Index [sPESI] score)[12][104] See our topic Pulmonary embolism for more information on criteria for admission for a patient with concomitant PE
Highly symptomatic DVT (e.g., severe pain and oedema in the presence of acute DVT requiring inpatient analgesia), or phlegmasia cerulea dolens
The patient needs support with ongoing anticoagulation therapy that cannot be adequately arranged in the outpatient or emergency department setting
Co-existing comorbidity requiring hospital management.

In practice, most patients with risk factors for bleeding that require close observation (e.g., chronic liver disease with or without varices, recent or prior gastrointestinal bleeding, chronic renal stones with recurrent haematuria, bleeding disorder, malignancy, recent stroke, or prior intracranial haemorrhage) can be managed at home unless they are actively bleeding. Seek advice from a senior colleague if you are unsure.

ACUTE

initiation-phase therapy: confirmed proximal DVT of the leg

no contraindication to anticoagulation: non-pregnant

1st line – anticoagulation

Back

1st line –

anticoagulation

The initiation phase covers the period up to 10 days following diagnosis of DVT.[26]

Give anticoagulation (unless contraindicated) to all patients if they have a proximal DVT.[12][26][27] The National Health Institute for Health and Care Excellence (NICE) in the UK recommends that patients with proximal DVT of the leg should receive anticoagulation for at least 3 months.[12]

Note that a separate initiation phase may only be required if the patient is receiving warfarin, because warfarin requires a loading period. In UK practice, direct oral anticoagulants (DOACs) are more widely used than warfarin; therefore, the initiation and treatment phases are usually combined, spanning the period from diagnosis to 3 months.
The aim of the initiation phase is to stop the active prothrombotic state and to inhibit thrombus propagation and embolisation.
Anticoagulation is the mainstay of therapy for the treatment of DVT and can:
- Prevent propagation/progression of the thrombus in the deep veins in the legs
- Reduce the risk of pulmonary embolism
- Reduce the risk of recurrent DVT.

Base your choice of anticoagulant on the patient’s comorbidities and contraindications as well as taking account of local guidelines.

If the patient has active cancer, renal impairment, or hepatic impairment, or is at extremes of body weight, see Confirmed proximal DVT: special patient groups below.

For all other patients with confirmed proximal DVT, start anticoagulation as soon as possible with apixaban or rivaroxaban (these are examples of DOACs); a low molecular weight heparin (LMWH) such as enoxaparin or dalteparin is an alternative if these are unsuitable.[12][26]

If using rivaroxaban or apixaban, note that these drugs may be started without the need for lead-in therapy with a parenteral anticoagulant first.[12]

Acute-phase treatment consists of an increased dose of the oral anticoagulant over the first 3 weeks (for rivaroxaban), or over the first 7 days (for apixaban).[27]

If using LMWH, continue treatment for at least 5 days.[12]

If ongoing anticoagulation will be with edoxaban or dabigatran, note that at least 5 days of lead-in therapy with LMWH is required first
OR
If ongoing anticoagulation will be with warfarin, start warfarin within 24 hours of diagnosis and ensure overlap with LMWH for at least 5 days or until the international normalised ratio (INR) is ≥2 for at least 24 hours (whichever is longer).[12]

Practical tip

Never give a DOAC simultaneously with parenteral anticoagulation.

While warfarin is started at the same time as a parenteral anticoagulant and overlapped for at least 5 days or until the INR is ≥2 for at least 24 hours (whichever is longer), DOACs should never be overlapped or given at the same time as a parenteral anticoagulant.
Apixaban and rivaroxaban may be started without the need for lead-in therapy with a parenteral anticoagulant first.
However, dabigatran and edoxaban require at least 5 days lead-in therapy with a parenteral anticoagulant before starting treatment. The parenteral anticoagulant should be stopped before dabigatran or edoxaban are started.

Confirmed proximal DVT: special patient groups

Be aware of special patient groups, including those with active cancer, renal impairment, or hepatic impairment, and patients at extremes of body weight. These groups will need a tailored approach to anticoagulant therapy.[12] Check your local protocols and consider seeking advice from a haematologist, particularly if the patient has triple-positive antiphospholipid syndrome (although this is unlikely to be known before anticoagulants are started).

Active cancer

Check local protocols for these patients. UK-based NICE recommends using a DOAC first-line.[12] Take into account the tumour site, the patient’s bleeding risk, and interactions with other drugs, including those being used to treat the cancer.[12] If a DOAC is unsuitable, NICE recommends using either:[12] [ ]

LMWH alone
OR
LMWH overlapped with a vitamin K antagonist (VKA); warfarin is the most commonly used VKA in practice. Ensure overlap of the two drugs for at least 5 days or until the INR is ≥2 in two consecutive readings followed by a VKA on its own.
- Note that warfarin is rarely used in UK practice for a patient with active cancer.

Renal impairment

Seek advice from a haematologist for these patients. NICE in the UK recommends the following approach based on estimated creatinine clearance (CrCl).[12]

For patients with CrCl 15-50 mL/minute, offer one of:
- Apixaban (use caution if CrCl is 15-29 mL/minute)
- Rivaroxaban (use caution if CrCl is 15-29 mL/minute)
- LMWH or unfractionated heparin (UFH), which can be overlapped with a VKA (warfarin is the most commonly used VKA in practice); overlap for at least 5 days or until the INR is at least 2.0 in 2 consecutive readings, followed by a VKA on its own) or used as lead-in therapy before starting edoxaban. LMWH or UFH can also be used as lead-in therapy before starting dabigatran if CrCl is ≥30 mL/minute.
For patients with CrCl <15 mL/minute offer one of:
- LMWH or UFH, which can be overlapped with a VKA (warfarin is the most commonly used VKA in practice). Ensure overlap of the two drugs for at least 5 days or until the INR is ≥2 in two consecutive readings followed by a VKA on its own
- LMWH alone
- UFH alone.

Check your local drug formulary for any monitoring requirements or dose adjustments in renal impairment, particularly if CrCl is <15 mL/minute.[12]

Practical tip

Warfarin is safe to use in patients with renal impairment with no dose adjustments necessary. However, monitor the INR more carefully in these patients.

Hepatic impairment

Note that choice of anticoagulant for a patient with hepatic impairment depends on the underlying cause and severity of hepatic impairment.

In practice, patients may have acute, mild hepatic impairment (e.g., secondary to intercurrent illness) and, once their hepatic impairment has resolved, they may be treated with a DOAC.
DOACs are generally not recommended in patients with moderate to severe chronic liver disease (Child-Pugh class B or C).[27] However, apixaban may be used in selected patients, and LMWH or UFH are also options. In practice, overlap both LMWH and UFH with warfarin, unless cancer is present. Use warfarin with caution if the patient’s baseline INR is elevated; extended-duration LMWH may be preferred.[119]

NICE in the UK doesn’t give specific recommendations for patients with hepatic impairment.

Check your local drug formulary for any dose adjustments in hepatic impairment.

Extremes of body weight

Check your local protocols and consider seeking advice from a haematologist or a multdisciplinary team before choosing the most appropriate anticoagulant for these patients.[12]

In UK practice, a DOAC may be used if the patient weighs up to 120 kg, and rivaroxaban or apixaban may be used if the patient weighs >120 kg.[120]
However, NICE recommends using an anticoagulant with monitoring of therapeutic levels (e.g., warfarin) if the patient weighs <50 kg or >120 kg, and checking any required dose adjustments.[12]

Practical tip

Drug-drug interactions may increase the risk of bleeding in patients receiving anticoagulation, particularly when anticoagulation is combined with antiplatelet therapy.[121] In practice, aspirin is generally stopped while the patient is receiving anticoagulation, unless there is a strong indication to continue it. Seek advice if in doubt. Both the pharmacodynamic (e.g., non-steroidal anti-inflammatory drugs, selective serotonin-reuptake inhibitors) and pharmacokinetic (e.g., amiodarone, rifampicin) interactions should be thoroughly evaluated prior to initiation. In particular, commonly overlooked interactions include those between a DOAC and phenytoin, carbamazepine, and HIV protease inhibitors.

Primary options

No special considerations; active cancer

apixaban: 10 mg orally twice daily for 7 days, followed by 5 mg twice daily

No special considerations; active cancer

rivaroxaban: 15 mg orally twice daily for 21 days, followed by 20 mg once daily

Active cancer

edoxaban: start following initial use of a parenteral anticoagulant for at least 5 days; body weight ≤60 kg: 30 mg orally once daily; body weight >60 kg: 60 mg orally once daily

Active cancer

dabigatran: start following initial use of a parenteral anticoagulant for at least 5 days; 18-74 years of age: 150 mg orally twice daily; 75-79 years of age: 110-150 mg orally twice daily; ≥80 years of age: 110 mg orally twice daily

Secondary options

No special considerations

edoxaban: start following initial use of a parenteral anticoagulant for at least 5 days; body weight ≤60 kg: 30 mg orally once daily; body weight >60 kg: 60 mg orally once daily

No special considerations

enoxaparin: uncomplicated patients with low risk of recurrence: 1.5 mg/kg subcutaneously every 24 hours; patients with risk factors: 1 mg/kg subcutaneously every 12 hours

dalteparin: patients with increased risk of bleeding: 100 units/kg subcutaneously every 12 hours; patients with no increased risk of bleeding: 200 units/kg subcutaneously every 24 hours, maximum 18,000 units/dose

-- AND --

warfarin: 5-10 mg orally once daily initially, adjust dose according to target INR

Active cancer

enoxaparin: 1 mg/kg subcutaneously every 12 hours

Active cancer

dalteparin: 200 units/kg subcutaneously once daily for the first 30 days, followed by 150 units/kg once daily for 5 months, maximum 18,000 units/dose

Active cancer

enoxaparin: 1 mg/kg subcutaneously every 12 hours

dalteparin: 200 units/kg subcutaneously once daily for the first 30 days, followed by 150 units/kg once daily for 5 months, maximum 18,000 units/dose

-- AND --

warfarin: 5-10 mg orally once daily initially, adjust dose according to target INR

Primary options

No special considerations; active cancer

apixaban: 10 mg orally twice daily for 7 days, followed by 5 mg twice daily

No special considerations; active cancer

rivaroxaban: 15 mg orally twice daily for 21 days, followed by 20 mg once daily

Active cancer

edoxaban: start following initial use of a parenteral anticoagulant for at least 5 days; body weight ≤60 kg: 30 mg orally once daily; body weight >60 kg: 60 mg orally once daily

Active cancer

Secondary options

No special considerations

edoxaban: start following initial use of a parenteral anticoagulant for at least 5 days; body weight ≤60 kg: 30 mg orally once daily; body weight >60 kg: 60 mg orally once daily

No special considerations

enoxaparin: uncomplicated patients with low risk of recurrence: 1.5 mg/kg subcutaneously every 24 hours; patients with risk factors: 1 mg/kg subcutaneously every 12 hours

-- AND --

warfarin: 5-10 mg orally once daily initially, adjust dose according to target INR

Active cancer

enoxaparin: 1 mg/kg subcutaneously every 12 hours

Active cancer

dalteparin: 200 units/kg subcutaneously once daily for the first 30 days, followed by 150 units/kg once daily for 5 months, maximum 18,000 units/dose

Active cancer

enoxaparin: 1 mg/kg subcutaneously every 12 hours

dalteparin: 200 units/kg subcutaneously once daily for the first 30 days, followed by 150 units/kg once daily for 5 months, maximum 18,000 units/dose

-- AND --

warfarin: 5-10 mg orally once daily initially, adjust dose according to target INR

Back to drug information with added comorbidities

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Show drug information for a patient with no comorbidities

Primary options

No special considerations; active cancer

apixaban

No special considerations; active cancer

rivaroxaban

Active cancer

edoxaban

Active cancer

dabigatran

Secondary options

No special considerations

edoxaban

No special considerations

dabigatran

No special considerations

enoxaparin

dalteparin

-- AND --

warfarin

Active cancer

enoxaparin

Active cancer

dalteparin

Active cancer

enoxaparin

dalteparin

-- AND --

warfarin

Plus – physical activity

Consider – compression stockings

Back

Consider –

compression stockings

Additional treatment recommended for SOME patients in selected patient group

Consider using compression stockings to manage leg symptoms such as pain, oedema, and residual venous obstruction.[12][26]

The National Institute for Health and Care Excellence in the UK does not recommend using compression stockings to prevent post-thrombotic syndrome.[12] This is debated in the literature; consult your local protocol.[131] [ ]
Explain to the patient how to use the stockings, how long they should be worn, and when they should be replaced.[12]

no contraindication to anticoagulation: pregnant

1st line – low molecular weight heparin

Back

1st line –

low molecular weight heparin

The initiation phase covers the period up to 10 days following diagnosis of DVT.[26]

Give anticoagulation (unless contraindicated) to all patients if they have a proximal DVT.[12][26][27] The National Health Institute for Health and Care Excellence in the UK recommends that patients with proximal DVT of the leg should receive anticoagulation for at least 3 months.[12]

The aim of the initiation phase is to stop the active prothrombotic state and to inhibit thrombus propagation and embolisation.

Base your choice of anticoagulant on the patient’s comorbidities and contraindications as well as taking account of local guidelines.

Use a weight-adjusted dose of a low molecular weight heparin (LMWH) in patients who are pregnant because LMWH does not cross the placenta.[26]

Do not routinely measure peak anti-Xa activity in patients who are pregnant (or in the postnatal period), except in patients who weigh <50 kg or ≥90 kg or those with renal impairment.[26]

Do not give a direct oral anticoagulant (DOAC) or vitamin K antagonist (e.g., warfarin) during pregnancy as they may cross the placenta.[26] Never give a DOAC if the patient is breasfeeding.[26] Warfarin appears to be safe to use in breastfeeding but in practice it may not be preferred (over LMWH) by the patient because it requires regular monitoring of international normalised ratio (INR).

Primary options

enoxaparin: body weight <50 kg: 40 mg subcutaneously twice daily; body weight 50-69 kg: 60 mg subcutaneously twice daily; body weight 70-89 kg: 80 mg subcutaneously twice daily; body weight ≥90 kg: 100 mg subcutaneously twice daily

dalteparin: body weight <50 kg: 5000 units subcutaneously twice daily; body weight 50-69 kg: 6000 units subcutaneously twice daily; body weight 70-89 kg: 8000 units subcutaneously twice daily; body weight ≥90 kg: 10,000 units subcutaneously twice daily

Plus – physical activity

Consider – compression stockings

Back

Consider –

compression stockings

Additional treatment recommended for SOME patients in selected patient group

Consider using compression stockings to manage leg symptoms such as pain, oedema, and residual venous obstruction.[12][26]

The National Institute for Health and Care Excellence in the UK does not recommend using compression stockings to prevent post-thrombotic syndrome.[12] This is debated in the literature; consult your local protocol.[131] [ ]
Explain to the patient how to use the stockings, how long they should be worn, and when they should be replaced.[12]

contraindication to anticoagulation

1st line – consider anticoagulation OR an IVC filter

Back

1st line –

consider anticoagulation OR an IVC filter

The initiation phase covers the period up to 10 days following diagnosis of DVT.[26] The aim of this phase is to stop the active prothrombotic state and to inhibit thrombus propagation and embolisation.

Consult a haematologist if the patient has a contraindication to anticoagulation.

Many patients with relative contraindications will still be able to have a different choice or altered dose of anticoagulation, but a specialist opinion is needed to weigh up the benefit-risk balance.
Absolute contraindications are rare but include:[136]
- Active bleeding
- Recent intracranial haemorrhage
- Recent, planned, or emergent surgery or procedure with high bleeding risk
- Platelet count <50,000/uL
- Severe bleeding diathesis.
Relative contraindications include:[136]
- Recurrent but inactive gastrointestinal bleeding
- Intracranial or spinal tumour
- Recent, planned, or emergent surgery or procedure with intermediate bleeding risk
- Major trauma including cardiopulmonary resuscitation
- Aortic dissection.
Remember, too, that each anticoagulant may have its own specific relative and absolute contraindications (e.g., heparin is contraindicated in patients with a history of heparin-induced thrombocytopenia) and these should be checked before starting treatment.

Practical tip

Peptic ulcer disease with no history of bleeding or faecal occult blood is not a contraindication to anticoagulation.[136]
Anticoagulation is safe in most trauma and neurosurgical patients after the first or second postoperative week and in most stroke patients without haemorrhage.[136]
Patients with spinal cord injury without haematomyelia may still be considered for anticoagulation.[136]

Consider a retrievable inferior vena cava (IVC) filter for any patient with confirmed proximal DVT who is deemed unsuitable for anticoagulation after discussion with a haematologist.[12][26][27] The aim of an IVC filter is to prevent embolisation to pulmonary embolism.[26]

Presence of an IVC filter is associated with a doubling of the long-term risk of recurrent lower-extremity DVT.
If the contraindication to anticoagulation has resolved, assess the patient for initiation of anticoagulation and removal of the IVC filter.[27]

Practical tip

Always document the plan for IVC filter removal at the time it is inserted. Forgotten IVC filters can lead to significant long-term complications.

Plus – physical activity

Consider – compression stockings

Back

Consider –

compression stockings

Additional treatment recommended for SOME patients in selected patient group

Consider using compression stockings to manage leg symptoms such as pain, oedema, and residual venous obstruction.[12][26]

The National Institute for Health and Care Excellence in the UK does not recommend using compression stockings to prevent post-thrombotic syndrome.[12] This is debated in the literature; consult your local protocol.[131] [ ]
Explain to the patient how to use the stockings, how long they should be worn, and when they should be replaced.[12]

initiation phase therapy: confirmed distal DVT of the leg

1st line – repeat imaging of the deep veins OR anticoagulation

Back

1st line –

repeat imaging of the deep veins OR anticoagulation

If a whole-leg ultrasound confirms distal (calf) DVT, check your local protocol for advice on whether and how to start anticoagulation; guidelines vary in terms of their recommendations.

In the UK, common practice is to:
- Start anticoagulation unless the patient has a high risk of bleeding or the DVT is not extensive (<5 cm)
- Seek advice from a haematologist if the patient has a high bleeding risk or the DVT is not extensive.
The European Society for Vascular Surgery recommends considering anticoagulation based on the patient’s symptoms, risk factors for extension, and bleeding risk.[26]
Note that the National Institute for Health and Care Excellence in the UK does not give recommendations for distal (calf) DVT.[12]

If anticoagulation is suitable, use the same regimens as for proximal DVT (see No contraindication to anticoagulation: pregnant under Initiation-phase therapy: confirmed proximal DVT of the leg above).[130] Take into account the patient’s comorbidities, contraindications, and your local guidelines.

If anticoagulation is not suitable, or contraindicated, check your local protocol to determine further management. The European Society for Vascular Surgery recommends arranging clinical reassessment and repeat whole leg ultrasound after 1 week.[26]

Risk factors for extension include:[130]

Positive D-dimer
Extensive DVT (e.g., >5 cm long)
DVT involving multiple veins
DVT >7 mm in maximum diameter (however, in practice this measurement is not routinely reported)
DVT close to the proximal veins
Absence of any reversible provoking factor
Active cancer
Past history of venous thromboembolism
Patient being managed in hospital.

Plus – physical activity

Consider – compression stockings

Back

Consider –

compression stockings

Additional treatment recommended for SOME patients in selected patient group

Consider using compression stockings to manage leg symptoms such as pain, oedema, and residual venous obstruction.[12][26]

The National Institute for Health and Care Excellence in the UK does not recommend using compression stockings to prevent post-thrombotic syndrome.[12] This is debated in the literature; consult your local protocol.[131] [ ]
Explain to the patient how to use the stockings, how long they should be worn, and when they should be replaced.[12]

ONGOING

treatment-phase therapy: confirmed DVT of the leg

1st line – maintain anticoagulation

Back

1st line –

maintain anticoagulation

The treatment phase covers the period from initiation to 3 months following diagnosis of DVT.[26] The aim of the treatment phase is to prevent new thrombus while the original clot is stabilised and intrinsic thrombolysis is under way.

In UK practice, because direct oral anticoagulants (DOACs) are more widely used than warfarin, the initiation and treatment phases are usually combined, spanning the period from diagnosis to 3 months. A separate initiation phase may only be required if the patient is receiving warfarin, because warfarin requires a loading period.
The aim of the treatment phase is to prevent new thrombus while the original clot is stabilised and intrinsic thrombolysis is under way.

DOACs

If the patient is taking dabigatran or edoxaban, continue the same dose started in the initiation phase for at least 3 months.[27]

However, if the patient’s renal function declines significantly, the DOAC should be discontinued.[27] In practice, switch to an alternative anticoagulant (unless the patient has a very low-risk DVT [e.g., small distal DVT]).

If the patient is taking apixaban or rivaroxaban, adjust the dose after the initiation phase (at 7 days for apixaban, and 21 days for rivaroxaban).[27]

Warfarin

Monitor the patient’s international normalised ratio (INR). The frequency of measurements depends on the stability of INR values.

In practice, measure INR every 3 to 4 days during initial dose titration if the patient is being managed as an outpatient, with the time between measurements progressively extending if values remain in range. However, if the patient is in hospital, consider measuring INR daily, particularly if they are acutely unwell.
Maintain a target range of 2 to 3 (target INR 2.5), unless anticoagulation is also being used for a separate indication that requires a higher target INR.[27]

Low molecular weight heparin (LMWH)

If extended LMWH is used, the dosing strategy is agent-specific; check your local protocol and seek advice from a pharmacist/haematologist if you are unsure. Adjust the LMWH dose to any change in the patient’s weight or creatinine clearance.

See the No contraindication to anticoagulation treatments under Initiation-phase therapy: confirmed proximal DVT of the leg above for more information about anticoagulation.

Plus – physical activity

Consider – compression stockings

Back

Consider –

compression stockings

Additional treatment recommended for SOME patients in selected patient group

Consider using compression stockings to manage leg symptoms such as pain, oedema, and residual venous obstruction.[12][26]

The National Institute for Health and Care Excellence in the UK does not recommend using compression stockings to prevent post-thrombotic syndrome.[12] This is debated in the literature; consult your local protocol.[131] [ ]
Explain to the patient how to use the stockings, how long they should be worn, and when they should be replaced.[12]

extended-phase therapy: confirmed DVT of the leg

1st line – consider extended anticoagulation

Back

1st line –

consider extended anticoagulation

The extended phase covers the period from 3 months following DVT to indefinite.[26] Bear in mind that not all patients will need continued anticoagulation beyond 3 months. The aim of the extended phase is secondary prevention of new venous thromboembolism. See the Prevention section for other methods of secondary prevention aside from anticoagulation.

Duration

Discuss with a senior colleague whether to continue anticoagulation beyond 3 months if the patient has a first presentation of proximal DVT. This decision should assess the individual patient’s risk of recurrence of DVT versus bleeding risk, as well as considering whether the DVT was provoked or unprovoked.[12] Discuss the risks and benefits of long-term anticoagulation with the patient, and take their preferences into account.[12]

A provoked DVT is a DVT associated with a major transient risk factor that was present in the 3 months prior to the DVT.[12]
An unprovoked DVT is a DVT in a patient who had no pre-existing, major, transient, provoking risk factor in the prior 3 months.[12]
Major provoking risk factors include: major surgery; trauma; significant immobility (bedbound, unable to walk unaided, or likely to spend a substantial proportion of the day in bed or in a chair); pregnancy or puerperium; use of oral contraceptive/hormone replacement therapy.[12]

In general, anticoagulation can usually be stopped after 3 months (or 3-6 months for people with active cancer) if the DVT was provoked, as long as the major transient risk factor is no longer present and the clinical course has been uncomplicated.[12]

In the UK, some centres may continue anticoagulation beyond 3 months for patients with a minor transient risk factor (e.g., minor surgery).

Anticoagulation is usually continued for longer than 3 months if the DVT was unprovoked.[12]

In practice, patients with persisting risk factors (e.g., active cancer, autoimmune conditions such as systemic lupus erythematosus and inflammatory bowel disease) usually continue anticoagulation long-term, unless they had a major provoking risk factor (e.g., major surgery).
If the patient has active cancer, anticoagulation is continued for at least 6 months.[12] In practice, this will be for at least the duration of cancer treatment, or until remission is achieved.

Annually reassess the risks/benefits of continuing anticoagulation, as well as the patient's general health and treatment preferences, in all patients receiving extended treatment beyond 3 months.[12][60]

Choice of anticoagulant

In general, offer continued treatment with the anticoagulant used in the acute phase if it is well tolerated.[12]

If the patient has been started on a direct oral anticoagulant other than apixaban and this is not well tolerated, or the clinical situation or patient preference has changed, the National Institute for Health and Care Excellence in the UK recommends to consider switching to apixaban if the patient does not have renal impairment, active cancer, established triple-positive antiphospholipid syndrome, or extreme body weight (<50 kg or >120 kg).[12] However, in practice, many patients may prefer an alternative anticoagulant that can be taken as a once-daily regimen.
In patients taking apixaban who need ongoing anticoagulation for >6 months, consider a dose reduction.[122] In UK practice, if the patient is taking rivaroxaban in this scenario, a dose reduction may be considered if there is concern about the risk of bleeding.
In pregnant patients, continue low molecular weight heparin for the remainder of the pregnancy and for at least 6 weeks postnatally and until at least 3 months of treatment has been given in total.[123]
Note that warfarin is rarely used in UK practice for a patient with active cancer.

Consider aspirin if the patient declines or is unable to tolerate any form of oral anticoagulant.[12]

Primary options

No special considerations; active cancer

apixaban: continue 5 mg orally twice daily; decrease dose to 2.5 mg twice daily after completing at least 6 months of treatment

No special considerations; active cancer

rivaroxaban: continue 20 mg orally once daily; decrease dose to 10 mg once daily after completing at least 6 months of treatment

Active cancer

edoxaban: start following initial use of a parenteral anticoagulant for at least 5 days; body weight ≤60 kg: 30 mg orally once daily; body weight >60 kg: 60 mg orally once daily

Active cancer

Pregnant women

No special considerations

edoxaban: start following initial use of a parenteral anticoagulant for at least 5 days; body weight ≤60 kg: 30 mg orally once daily; body weight >60 kg: 60 mg orally once daily

No special considerations

warfarin: 5-10 mg orally once daily initially, adjust dose according to target INR

Active cancer

enoxaparin: 1 mg/kg subcutaneously every 12 hours

Active cancer

dalteparin: 200 units/kg subcutaneously once daily for the first 30 days, followed by 150 units/kg once daily for 5 months, maximum 18,000 units/dose

Tertiary options

aspirin: 75-150 mg orally once daily

recurrent venous thromboembolism

1st line – increase dose of anticoagulant OR switch to alternative anticoagulant

Back

1st line –

increase dose of anticoagulant OR switch to alternative anticoagulant

Seek advice from haematology for any patient who has a recurrent venous thromboembolism (VTE) despite adequate anticoagulation treatment. Recurrent VTE is unusual among patients receiving therapeutic-dose anticoagulant therapy, except in those with active cancer (7% to 9% on-therapy recurrence with low molecular weight heparin).[13][137][138]

Check adherence to anticoagulation treatment.[12]
Address other sources of hypercoagulability (e.g., underlying malignancy).[12]
Consider other reasons for reduced efficacy of anticoagulation (e.g., rivaroxaban not being taken with food).[139]

In the absence of any of the above issues, options include:[12]

Increasing the dose of anticoagulant
Changing to a different anticoagulant with a different mode of action.

Note that these recommendations are based on the National Institute for Health and Care Excellence guideline in the UK, which covers patients with proximal DVT only. In UK practice, some experts may apply these recommendations equally to patients with distal (calf) DVT in the absence of recommendations from guidelines. Seek advice from a specialist if needed.

Consider – IVC filter

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Deep vein thrombosis

Treatment algorithm

suspected DVT of the leg

with phlegmasia cerulea dolens

anticoagulation

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

immediate referral to a vascular surgeon

supportive care

without phlegmasia cerulea dolens

consider interim anticoagulation

Practical tip

decide on setting of care

initiation-phase therapy: confirmed proximal DVT of the leg

no contraindication to anticoagulation: non-pregnant

anticoagulation

Practical tip

Confirmed proximal DVT: special patient groups

Active cancer

Renal impairment

Practical tip

Hepatic impairment

Extremes of body weight

Practical tip

Primary options

No special considerations; active cancer

No special considerations; active cancer

Active cancer

Active cancer

Secondary options

No special considerations

No special considerations

No special considerations

Active cancer

Active cancer

Active cancer

These drug options and doses relate to a patient with no comorbidities.

Primary options

No special considerations; active cancer

No special considerations; active cancer

Active cancer

Active cancer

Secondary options

No special considerations

No special considerations

No special considerations

Active cancer

Active cancer

Active cancer

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

No special considerations; active cancer

No special considerations; active cancer

Active cancer

Active cancer

Secondary options

No special considerations

No special considerations

No special considerations

Active cancer

Active cancer

Active cancer

physical activity

compression stockings

no contraindication to anticoagulation: pregnant

low molecular weight heparin

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

physical activity

compression stockings

contraindication to anticoagulation

consider anticoagulation OR an IVC filter

Practical tip

Practical tip