Urgent Care Q&A – Ten Questions (and Answers) About Pulmonary Embolism (PE) and Venous Thromboembolism (VTE) – Q2 2023

Michael B. Weinstock, MD and Gita Pensa, MD

How common is pulmonary embolism (PE)?

  • The incidence of PE is approximately 60 to 120 cases per 100,000 population per year

How many patients die of PE?

  • Between 60,00 and 100,000 patients die from PE every year
  • PE is the 2nd leading cause of nontraumatic death in the U.S.
  • In patients with PE who are stable and less than 50 years old, the death rate is 1%

What is the pathophysiology of VTE? What are the two broad classifications of VTE?

  • When coagulation exceeds fibrinolysis, blood clots form.
  • Between 70-80% of blood clots start as thrombi in the deep veins in the lower extremities or pelvis
  • Only 6% are from deep veins in the upper extremities
  • Virchow triad: Venous stasis, hypercoagulability, endothelial injury
  • Other factors increasing clotting risk include local infection, venous compression, catheters, devices, trauma

What are the risk factors for PE?

  • Thrombophilias
  • Older age
  • Family history
  • Immobilization
  • Cancer
  • Estrogens (eg. oral contraceptives)
  • Pregnancy and post-partum

Is smoking a risk factor for PE?

  • No. But smoking does cause conditions which increase the risk of VTE/PE including cancer. Patients who are smokers and use estrogen containing contraceptives (especially over the age of 35) have an increased risk of VTE.

Is pregnancy a risk for PE?

  • Pregnancy is a risk for thromboembolism, but pregnant patients with shortness of breath or chest pain do not have a higher risk of thromboembolism compared to non-pregnant patients with the same symptoms.

 Is COVID-19 a risk for PE?

  • This is not clear. Even less clear is if the present day COVID-19 is an increased risk. Patients who have a risk of PE based on symptoms should be evaluated, but if there are no concerns for PE in patients with COVID-19, investigation does not need to take place.

Should an unprovoked PE prompt exploration for underlying cause and does this improve outcomes?

  • Yes! If the PE is unprovoked (not present with any risk factors above or with trauma or immobilization), evaluate for a hypercoagulable state or occult cancer.

Should all patients with syncope be evaluated for PE?

  • PE may present as unexplained syncope, but the incidence is low with only 0.6% of syncopal patients having a PE and only 3-4 patients with PE having syncope

 

How can we evaluate for PE at the bedside without lab or radiologic testing (is there a clinical decision rule)?

  • The PERC rule can safely be used to clinically exclude PE at the bedside of an Urgent Care.  30% to 50% of patients with a low clinician-assessed probability of PE can be clinically excluded with the PERC rule.

 

References: 

Freund Y, Cohen-Aubart F, Bloom B. Acute Pulmonary Embolism: A Review. JAMA. 2022 Oct 4;328(13):1336-1345. doi: 10.1001/jama.2022.16815. PMID: 36194215.