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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.

Pulmonary embolism

Haematology and transfusion · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull
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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.
  • PE unlikely means Wells score 4 or less: obtain D-dimer first; a negative validated result excludes PE, while a positive result requires CTPA or a suitable alternative scan.
  • CTPA is the usual confirmatory test. Use V/Q SPECT or planar scanning when contrast allergy, severe renal impairment, pregnancy radiation balance or a normal chest radiograph makes it preferable through the local imaging pathway.
  • For haemodynamically stable confirmed PE, offer apixaban or rivaroxaban first-line when suitable, with the same mandatory acute loading phases as DVT and at least 3 months of treatment.
  • For haemodynamically unstable PE, start continuous UFH and consider systemic thrombolysis; do not routinely thrombolyse stable PE solely because troponin or right-ventricular imaging is abnormal.
  • At three months, review provocation, cancer, APS, recurrence and bleeding, and investigate persistent limitation for post-PE syndrome or CTEPH rather than repeating D-dimer as surveillance.

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.

Major active bleeding, recent intracranial haemorrhage, recent brain or spinal surgery or suspected aortic dissection materially changes thrombolysis and anticoagulation decisions and requires immediate expert balance.

Pregnancy, severe kidney impairment, active cancer, triple-positive APS or platelets falling after heparin alters imaging or anticoagulant selection but must not produce untreated suspected PE.

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.

  1. If clinical suspicion is low and another diagnosis is feasible, consider PERC; otherwise calculate the two-level PE Wells score.
  2. For a score above 4, arrange immediate CTPA; for 4 or below, use D-dimer and image only when positive.
  3. Give interim therapeutic anticoagulation if the indicated D-dimer or imaging is delayed, unless a bleeding contraindication outweighs benefit.
Stable confirmed PEAnticoagulate and select place of care

Imaging confirms PE without haemodynamic instability.

  1. Assess RV strain, biomarkers, bleeding, comorbidity and a validated outpatient tool plus social ability to obtain and take treatment safely.
  2. Use apixaban or rivaroxaban first-line when suitable, or a renal, cancer, APS, pregnancy or interaction-adjusted alternative, for at least 3 months.
  3. Book the three-month recurrence and duration review and give a route for new bleeding, dyspnoea, syncope or persistent exercise limitation.

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.Review renal and hepatic function, active bleeding, pregnancy, APS and strong CYP3A4 or P-gp interactions. Do not omit the 7-day loading phase or use atrial-fibrillation reduction criteria for acute PE.
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.Baseline lupus anticoagulant or severe acute-phase change can make APTT unreliable, favouring anti-Xa monitoring. Review active bleeding, recent surgery, neuraxial intervention and HIT, and coordinate stopping and restarting around thrombolysis.
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Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
Sources

Sources and review status

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.

  • NICE NG158: venous thromboembolic diseases recommendationsUK PE probability, D-dimer, imaging, interim anticoagulation, reperfusion and duration pathway.
  • Resuscitation Council UK 2025: special circumstances guidelinesPE cardiac arrest, thrombolysis, embolectomy and prolonged CPR recommendations.
  • Actilyse 10 mg Summary of Product CharacteristicsLicensed alteplase regimen and contraindications for massive PE.
  • Eliquis 5 mg Summary of Product CharacteristicsLicensed apixaban acute and extended PE treatment dosing.
  • Heparin sodium 5,000 units/mL Summary of Product CharacteristicsUnfractionated-heparin treatment and safety context.

Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom