Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
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High-risk pulmonary embolism
Cardiac arrest, persistent hypotension, obstructive shock, syncope with hypoperfusion, severe hypoxaemia or rapidly worsening right-heart failure requires immediate resuscitation and reperfusion assessment.
Action: Call senior, critical-care and PE-response support, use ABCDE with cautious circulatory support, obtain bedside ECG, blood gas and echocardiography when transport is unsafe, give unfractionated heparin when appropriate, and use systemic thrombolysis for haemodynamically unstable confirmed or strongly suspected PE when bleeding risk permits; consider surgical or catheter embolectomy when thrombolysis is contraindicated or fails.
Synopsis
Apply probability-led pulmonary embolism diagnosis, distinguish haemodynamic emergency from stable disease, deliver correctly sequenced anticoagulation or reperfusion, and plan duration and post-PE follow-up from haematological risk.
PE presents with acute dyspnoea, pleuritic pain, tachypnoea, tachycardia, syncope, haemoptysis or DVT signs, but normal oxygen saturation, chest radiograph or ECG does not exclude it.
If overall clinical suspicion is low and another diagnosis is feasible, consider the PERC rule; otherwise calculate the two-level PE Wells score rather than ordering D-dimer indiscriminately.
PE likely means Wells score above 4: arrange immediate CTPA and give interim therapeutic anticoagulation if imaging cannot occur promptly unless contraindicated.
Key red flags
Persistent systolic hypotension, cool peripheries, confusion, oliguria, rising lactate or cardiac arrest indicates obstructive shock and overrides the routine D-dimer and outpatient pathway.
Cardiac arrest
Pulseless electrical activity with preceding dyspnoea, DVT risk or bedside RV dilatation should trigger the RCUK suspected-PE arrest pathway.
Investigation priorities
01
First-line: two-level PE Wells scoreFirst stepFirst line
Select imaging-first or D-dimer-first diagnosis in a haemodynamically stable patient.
02
First-line in unlikely PE: D-dimerFirst line
Exclude PE without imaging when probability is low.
Management branches
Stable suspected PEUse probability before testing
PE is possible but there is no persistent hypotension, shock or cardiac arrest.
If clinical suspicion is low and another diagnosis is feasible, consider PERC; otherwise calculate the two-level PE Wells score.
For a score above 4, arrange immediate CTPA; for 4 or below, use D-dimer and image only when positive.
Stable confirmed PEAnticoagulate and select place of care
Imaging confirms PE without haemodynamic instability.
Key medicines
ApixabanGive 10 mg orally twice daily for 7 days, then 5 mg twice daily for at least the remainder of the first 3 months; if extended prevention is selected after 6 months, 2.5 mg twice daily is the licensed reduced-intensity dose.
Unfractionated heparin for unstable PEUse the local weight-based intravenous UFH protocol, commonly an 80 units/kg bolus followed by 18 units/kg/hour, with bolus modification when bleeding risk is high and rapid titration by the validated anti-Xa or APTT method.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.