Questionnaire/history:

Sudden onset dyspnoea (80%)?

Gradual onset dyspnoea (3%)?

Pleuritic chest pain (49%)?

Retrosternal chest pain (right ventricular ischaemia)?

Syncope or pre-syncope (24%)?

Haemoptysis (6%)?

Cough (4%)?

Unilateral leg pain?

Unilateral leg swelling?

Past medial history?

Current medication?

- Oral contraceptive?

- HRT or oestrogenic hormones?

Known drug allergies?

Examination:

Respiratory rate?

- > 20 (95%)?

Blood pressure?

- Hypotension?

Heart rate?

- > 100 bpm (45%)?

Gallop rhythm?

Tricuspid regurgitant murmur?

Pleural rub?

Temperature?

- > 38 (4%)

Elevated JVP?

Investigations:

ECG?

- RV heart strain (40-45%)?

Risk assessment:

If ALL the following are negative the risk of PE is <2% so PE can safely be ruled out and there is no need to proceed to D-dimer testing:

- Age ≥ 50 years old

- HR ≥100

- SpO2 < 95%

- Unilateral leg swelling

- Haemoptysis

- Recent surgery or trauma (within 4 weeks requiring GA)

- Prior PE or DVT

- Hormone use (oral contraceptives, HRT or oestrogenic hormones in men or women)

Otherwise calculate Wells score for PE?

Clinical signs and symptoms of DVT (+3)?

PE is #1 diagnosis OR equally likely (+3)?

Heart rate > 100 (+1.5)?

Immobilization at least 3 days OR surgery in the previous 4 weeks (+1.5)?

Previous, objectively diagnosed PE or DVT (+1.5)?

Hemoptysis?

Malignancy with treatment within 6 months or palliative?

Management:

Wells score > 4 - PE likely

Refer urgently to secondary care for CTPA

If imaging cannot be done immediately offer interim anticoagulation (see below)

If imaging confirms PE offer or continue anticoagulation

If PE not identified on imaging consider a proximal leg vein US if DVT is suspected

If DVT is not suspected then stop anticoagulation and consider alternative diagnosis

Wells score 0-4 - PE unlikely

Arrange D dimer test with result available within 4 hours

Consider a point of care test if a laboratory test is not immediately available

If using point of care D-dimer use a quantitative test

Consider age-adjusted D-dimer thresholds for > 50 years as reduces false +ves and unnecessary imaging

If D-dimer test result cannot be obtained within 4 hours offer interim anticoagulation (see below)

If D-dimer is positive refer urgently for CTPA

If D-dimer is -ve then stop anticoagulation and consider alternative diagnosis

Interim anticoagulation

Choose an anticoagulant that can be continued if PE or DVT is confirmed (see below)

Baseline bloods (FBC, UEs, LFTs, PT, APTT) but do not wait for the results before starting anticoagulation

Anticoagulation for confirmed PE

Offer anticoagulation for at least 3 months - take baseline bloods if not already done so. 1st line:

- Apixaban 10 mg BD for 7 days then 5 mg BD or

- Rivaroxaban 15 mg BD for 21 days then 20 mg OD

If unsuitable:

- LMWH for 5 days followed by dabigatran or edoxaban or

- LMWH concurrently with warfarin until INR > 2.0 for 2 consecutive readings then warfarin alone

Anticoagulation in special situations:

Extremes of body weight: < 50kg (overdosed) or > 120kg (underdosed)

Monitor therapeutic levels - for most this will mean LMWH/warfarin, however

Recent guidance from ISTH July 2021 has reviewed evidence on DOACs in people with HIGH BMI and concludes 'For treatment of VTE, we suggest that standard doses of rivaroxaban or apixaban are among appropriate anticoagulant options regardless of high BMI and weight'.

Renal impairment (use estimated creatinine clearance NOT eGFR):

Estimated creatinine clearance: 15 -50ml/min:

- Apixaban - no dose adjustment required

- Rivaroxaban - after 21 days use 15 mg OD rather than 20mg

- LMWH concurrently with warfarin until INR > 2.0 for 2 consecutive readings then warfarin alone

Estimated creatinine clearance < 15ml/min:

- LMWH

- LMWH concurrently with warfarin until INR > 2.0 for 2 consecutive readings then warfarin alone

Active cancer:

Offer anticoagulation for 3-6 months

When choosing agent take into account tumour site, interactions with other drugs including cancer drugs and patients bleeding risk

Consider DOAC

If DOAC unsuitable consider LMWH alone or warfarin

For patients in remission follow standard pathway

Antiphospholipid Syndrome:

LMWH concurrently with warfarin until INR> 2.0 for 2 consecutive readings then warfarin alone

Long term anticoagulation

Provoked PE:

Consider stopping anticoagulation after 3 months (3-6 months for active cancer) if provoking factor is no longer present and clinical course has been uncomplicated

Unprovoked PE:

Consider continuing anticoagulation beyond 3 months (6 months for active cancer) based on balance of risks of VTE versus bleeding risk. Take patient preference into account

Patients with low bleeding risk are likely to continue to benefit from continuing anticoagulation

HAS-BLED score can be used to assess risk. Consider stopping anticoagulation if score >4 and not modifiable

For patients who decline continued anticoagulation consider Aspirin 75-150 mg OD

Investigation for cancer

Do not offer further investigations for cancer to patients with unprovoked DVT or PE unless they have relevant clinical symptoms or signs

Review medical history, offer examination and baseline bloods

Thrombophilia screening

Consider antiphospholipid antibodies in unprovoked DVT if it is planned to stop anticoagulation

Consider hereditary thrombophilia screen in unprovoked DVT when a first-degree relative has a history of DVT or PE and it is planned to stop anticoagulation

Do not offer testing to those continuing on anticoagulation

Do not offer testing to patients with a provoked DVT

Reference(s):

NICE NG158