CanadiEM Frontline Primer

CanadiEM Frontline Primer – Pulmonary Embolism

In Medical Concepts by Ryan O'ReillyLeave a Comment

Points to focus upon

How common is this:
Pulmonary embolism is a relatively rare diagnosis (0.08%) in the emergency department, however, due to the potential for adverse outcomes, it is important to maintain a high degree of suspicion among vulnerable populations.​1​ Approximately half of the patients are admitted to hospital in Canada, although this proportion is much higher in the USA (90%).​2,3​

DDx that present similarly:
Highly variable presentation – DDx will depend on presenting complaint, however, the main concerns are typically: ACS, Pericarditis, Pneumonia, Asthma/COPD Exacerbation, Pneumothorax, Rib Fracture, Costochondritis, Anxiety.

It is important to assess for DVT simultaneously.

Considerations in the age of COVID-19 for your safety:
The most common presenting complaints for PE are dyspnea and chest pain, both of which have been commonly observed in COVID-19 patients. Take appropriate precautions when assessing patients for these complaints.


  • CBC, BUN/Cr, Lytes
  • D-dimer
  • CXR, CTPA or V/Q scan
  • ECG*
  • Consider troponin and POCUS where applicable.

*ECG (up to 1/3 of patients): tachycardia, S1T3Q3T3, signs of pulmonary HTN/right heart strain (symmetrical T-wave inversion in anterior/inferior leads), new RBB


Stable Patients

For stable outpatients starting anticoagulant therapy with follow-up in the community setting is very appropriate, even for those with pulmonary embolism. The PESI score can guide this decision, as will a conversation with the family physician or specialist who will be following this patient.

Oral Anticoagulation regimes usually include:
Warfarin (bridged with 5-7 days of Low Molecular Weight Heparin subcutaneous injections, eg. enoxaparin)
Direct Oral Anticoagulant (Dabigatran, Rivaroxaban, or Apixaban)
– Pregnant patients will require other forms of treatment such as low molecular weight heparin injections.
Read more here.

Unstable Patients:

-Hemodynamic stabilization via supportive resuscitation
– Admission with monitoring
– Heparinzation is usually the mainstay of therapy and should be initiated in the ED. Choice of low molecular weight heparin (LMWH) vs. unfractionated heparin depends on various factors. Please refer to these recent guidelines (section XXV) for further details.
– May require consulting thrombosis/hematology/ICU service to discuss the role of targeted thrombolytics or other therapies.

Clinical Decision Rules:

Recommended readings, videos, and podcasts

The following is part of the CanadiEM Frontline Primer. An introduction to the primer can be found here. To return to the Primer content overview click here.

This post was edited by Dr. Sonja Wakeling MD and Dr. Brent Thoma MD FRCPC. This post was copyedited and uploaded by Evan Formosa.


  1. 1.
    Schissler AJ, Rozenshtein A, Schluger NW, Einstein AJ. National trends in emergency room diagnosis of pulmonary embolism, 2001–2010: a cross-sectional study. Respir Res. March 2015. doi:10.1186/s12931-015-0203-9
  2. 2.
    KOVACS MJ, HAWEL JD, REKMAN JF, LAZO-LANGNER A. Ambulatory management of pulmonary embolism: a pragmatic evaluation. Journal of Thrombosis and Haemostasis. July 2010:2406-2411. doi:10.1111/j.1538-7836.2010.03981.x
  3. 3.
    Mansour S, Alotaibi G, Wu C, McMurtry MS. Trends in admission rates and in-hospital stay for venous thromboembolism. Thrombosis Research. August 2017:149-154. doi:10.1016/j.thromres.2017.06.012

Ryan O'Reilly

Ryan O'Reilly is a Family Medicine Resident at McMaster University. His interests include medical education, PoCUS, decision analysis, and following the every move of his favourite team, Liverpool FC.

Teresa Chan

Senior Editor at CanadiEM
Emergency Physician. Medical Educator. #FOAMed Supporter, Producer and Researcher. Chief Strategy Officer of CanadiEM. Associate Professor, Division of Emergency Medicine, Department of Medicine, McMaster University.