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Page last updated:
24 January 2024
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Management of suspected deep vein thrombosis (DVT) and pulmonary embolism (PE)
The information below is based on NICE Guideline NG158 Venous thromboembolic diseases: diagnosis, management and thrombophilia testing (March 2020, updated August 2023).
Please also refer to: Anticoagulation prescribing guidance page, which includes the Cockcroft-Gault formula for estimating creatinine clearance (CrCl).
NICE has produced a visual summary of the recommendations on diagnosis and initial management of suspected deep vein thrombosis (DVT) and pulmonary embolism (PE).
Where suspected DVT in pregnancy refer to Obstetrics/Medics in first instance.
Scoring
DVT
If DVT is suspected, use the 2 level DVT Wells score (see slider below)
If score is 2 or above:
Refer for ultrasound scan (within 4 hours)
- If positive scan,
- offer or continue anticoagulation treatment
- and if anticoagulation treatment is contraindicated, offer a mechanical intervention
- If negative scan, perform D-dimer test
- If this test is positive, repeat ultrasound scan 6-8 days later
- If this test is negative, stop interim anticoagulation and consider alternative diagnoses
Do not stop short-term anticoagulation when used for primary venous thromboembolism (VTE) prevention in people with COVID‑19 for people with a negative ultrasound scan and either a positive or negative D-dimer test.
If ultrasound cannot be obtained within 4 hours, perform D-dimer test, then offer interim therapeutic anticoagulation (see slider below), and an ultrasound scan with the result available within 24 hours.
If score is 1 or below:
Perform D-dimer test or offer interim therapeutic anticoagulation if the D-dimer test result cannot be obtained within 4 hours
- If positive, offer an ultrasound scan or interim anticoagulation and an ultrasound scan with the result available within 24 hours
- If negative, stop interim anticoagulation, but do not stop short-term anticoagulation when used for primary venous thromboembolism (VTE) prevention in people with COVID‑19
- Consider alternative diagnoses
PE
If PE is suspected, use the 2-level PE Wells score (see slider below)
If score is more than 4 points:
Offer a computed tomography pulmonary angiogram (CTPA) immediately if possible or offer interim therapeutic anticoagulation if CTPA cannot be done immediately
- If positive,
- offer or continue anticoagulation treatment
- and if anticoagulation treatment is contraindicated, offer a mechanical intervention
- If negative,
- and DVT is suspected, consider an ultrasound scan
- and DVT is not suspected, stop interim therapeutic anticoagulation, but do not stop short-term anticoagulation when used for primary venous thromboembolism (VTE) prevention in people with COVID‑19,
- Consider alternative diagnoses
If score is 4 points or less:
Perform D-dimer test or offer interim therapeutic anticoagulation if the D-dimer test result cannot be obtained within 4 hours
- If positive, offer a computed tomography pulmonary angiogram (CTPA) immediately if possible or offer interim therapeutic anticoagulation if CTPA cannot be done immediately
- If PE is identified offer or continue anticoagulation treatment or if anticoagulation treatment is contraindicated, offer a mechanical intervention
- If negative, stop interim therapeutic anticoagulation, but do not stop short-term anticoagulation when used for primary venous thromboembolism (VTE) prevention in people with COVID‑19
- Consider alternative diagnoses
| Clinical feature | Points |
| Active cancer (treatment ongoing, within 6 months, or palliative) | 1 |
| Paralysis, paresis or recent plaster immobilisation of the lower extremities | 1 |
| Recently bedridden for 3 days or more, or major surgery within 12 weeks requiring general or regional anaesthesia | 1 |
| Localised tenderness along the distribution of the deep venous system | 1 |
| Entire leg swollen | 1 |
| Calf swelling at least 3 cm larger than asymptomatic side | 1 |
| Pitting oedema confined to the symptomatic leg | 1 |
| Collateral superficial veins (non-varicose) | 1 |
| Previously documented DVT | 1 |
| An alternative diagnosis is at least as likely as DVT | -2 |
Clinical probability simplified score:
| DVT likely | 2 points or more |
| DVT unlikely | 1 point or less |
| Clinical feature | Points |
| Clinical signs and symptoms of DVT (minimum of leg swelling and pain with palpation of the deep veins) | 3 |
| An alternative diagnosis is less likely than PE | 3 |
| Heart rate more than 100 beats per minute | 1.5 |
| Immobilisation for more than 3 days or surgery in the previous 4 weeks | 1.5 |
| Previous DVT/PE | 1.5 |
| Haemoptysis | 1 |
| Malignancy (on treatment, treated in the last 6 months, or palliative) | 1 |
Clinical probability simplified scores:
| PE likely | More than 4 points |
| PE unlikely | 4 points or less |
When using interim therapeutic anticoagulation for suspected proximal DVT or PE:
- carry out baseline blood tests including full blood count, renal and hepatic function, prothrombin time (PT) and activated partial thromboplastin time (APTT)
- do not wait for the results of baseline blood tests before starting anticoagulation treatment
- review, and if necessary, act on the results of baseline blood tests within 24 hours of starting interim therapeutic anticoagulation.
Offer anticoagulation treatment, apixaban or rivaroxaban, for at least 3 months to people with confirmed proximal DVT or PE.
See sections 2.8.1 Parenteral anticoagulants, and 2.8.2 Oral anticoagulants
If neither apixaban nor rivaroxaban is suitable, or compliance is an issue offer:
- low molecular weight heparin (LMWH) for at least 5 days followed by dabigatran or edoxaban or
- LMWH concurrently with a vitamin K antagonist (VKA) 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
When selecting an appropriate treatment option, take into account adherence to treatment, access to healthcare facilities, clinical circumstances, contraindications, comorbidities, concurrent medications and patient preference. See below for recommendations for patients with specific clinical features to consider.
Patients with specific clinical features to consider
DVT or PE in people at extremes of body weight
- Consider anticoagulation treatment with regular monitoring of therapeutic levels for people with confirmed proximal DVT or PE who weigh less than 50 kg or more than 120 kg, to ensure effective anticoagulation.
PE with haemodynamic instability
- For people with confirmed PE and haemodynamic instability, offer continuous UFH infusion and consider thrombolytic therapy.
DVT or PE with renal impairment or established renal failure
(CrCl estimated using the Cockcroft Gault formula)
The Specialist Pharmacy Service (SPS) and local specialist renal teams recommend the use of a web based application such as MDCalc where actual bodyweight is used to calculate the Cockcroft-Gault CrCl. If height is added the different methods of adjusting for weight can be seen, providing a range of possible values for CrCl.
Where these results cross or are close to a CrCl level that may require a dose change, this can support the clinician making a dosing decision.
- CrCl 15 to 50 ml/min, offer one of:
- apixaban
- rivaroxaban
- LMWH for at least 5 days followed by:
- edoxaban or
- dabigatran if estimated creatinine clearance is 30 ml/min or above
- LMWH or UFH, given concurrently with a VKA 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
- CrCl < 15 ml/min, offer one of:
- LMWH
- UFH
- LMWH or UFH concurrently with a VKA 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
DVT or PE with active cancer
Offer people with active cancer and confirmed proximal DVT or PE anticoagulation treatment for 3 to 6 months. Review at 3 to 6 months according to clinical need. Take into account the tumour site, interactions with other drugs including those used to treat cancer, and the person's bleeding risk.
- Consider a direct-acting oral anticoagulant (DOAC)
- If a DOAC is not suitable, consider one of:
- LMWH
- LMWH and a VKA for at least 5 days or until INR at least 2.0 on 2 consecutive readings, then a VKA alone
DVT or PE with triple positive antiphospholipid syndrome
- Offer people with confirmed proximal DVT or PE and an established diagnosis of triple positive antiphospholipid syndrome LMWH concurrently with a VKA 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
Discuss long-term anticoagulation management with a specialist.
