Discharging ED patients with acute pulmonary embolism (PE) was not common and varied widely between facilities, according to the authors of a recent study.1

“The evidence that select ED patients with acute PE can be safely treated without hospitalization has continued to mount since 2000,” says David R. Vinson, MD, an EP with Kaiser Permanente and the study’s lead author.

Guidelines began recommending home management as early as 2003. “Yet, the practice has been slow to catch on, both here in the United States and abroad,” Vinson notes.

Of 2,387 patients with acute PE in 21 community EDs, 179 were discharged home. Patients selected for outpatient management demonstrated a low incidence of adverse outcomes. Of this group, 13 experienced a five-day PE-related return visit. All-cause, 30-day mortality was lower among home discharge patients compared with hospitalized patients (1.1% vs. 4.4%).

“We wanted ... to demonstrate the safety and effectiveness of outpatient care in a community setting and contribute to the shift in tide that we see coming in the next five to 10 years,” Vinson says.

Previously, researchers studied outpatient management of deep vein thrombosis and home care of PE.2,3 “EDs who send home a higher percentage of their PE population generally have two systemic processes in place,” Vinson notes. These EDs help physicians identify PE patients who may be eligible for outpatient management and facilitate timely follow-up after discharge. The 21 community hospitals in the new study are part of an integrated healthcare delivery system through which timely follow-up after ED discharge is possible. Most ED patients who are discharged home with acute PE receive follow-up in the outpatient setting within one week.4 “But we had no mechanism in place to help physicians identify low-risk PE patients who could safely forego hospitalization,” Vinson reports.

Despite the lack of evidence-based decision support, EPs sent home 7.5% of ED patients with acute PE. “The outcomes of these discharged patients were reassuring,” Vinson adds.

The researchers were surprised at how many admitted patients were categorized as low-risk (30-day, all-cause mortality = 0.3%).5 Vinson says many of these low-risk, low-mortality patients may have been fitting candidates for outpatient care.

The low percentage of home discharges suggests emergency clinicians may default to hospitalization for PE patients. One reason is that EPs generally are risk-adverse, Vinson offers. Knowing that some PE patients perform poorly has made physicians overly cautious with the whole population.

“But overcoming such caution may require nothing more than resetting the ED culture,” Vinson says.

Vinson notes that liability exposure can be reduced by establishing a clinical practice pathway that provides evidence-based guidance, carefully selecting low-risk patients eligible for home management, and informing patients about the indications for return visits.

“Ottawa University Hospital has demonstrated how even a simple set of exclusion criteria can transform PE site-of-care practice patterns,” Vinson says.6 In a not-yet-published trial, EPs were provided with electronic clinical decision support with risk stratification. “This increased our outpatient management by 60%,” Vinson reports. Other investigators recently assessed PE testing rates among 3,024 pulmonary embolism rule-out criteria- (PERC) negative patients who presented to an urban, academic ED.7 Many of these patients underwent testing for PE, including CT or ventilation-perfusion scan without D-dimer risk stratification.

“Our primary motivation for doing this study was our anecdotal observation that many patients undergo testing for PE even when they are PERC-negative,” says Troy Madsen, MD, one of the study’s authors. The original PERC study was performed in 2004 and validated in 2008.

“The idea behind PERC is to reduce the amount of testing performed,” Madsen explains. The researchers wondered how many patients who were PERC-negative continued to undergo testing for PE, because several studies have demonstrated that testing in this group is unnecessary.

“The greatest surprise for us ... was that 25% of patients who came to the ED with chest pain and/or shortness of breath, and who were PERC-negative, had testing for PE,” Madsen reports. This was compared to 35% of those who were not PERC-negative and in whom PE testing potentially would be indicated if the physician was concerned for PE.

“Our study took place at an academic medical center, where you would assume physicians would be more willing to adopt evidence-based practices,” Madsen says. The researchers did not expect to find 100% compliance with the PERC. But to find so many patients underwent PE testing was a surprise.

“Sometimes, I think we try to avoid liability in the ED by performing more testing than is necessary,” Madsen says. It may have been a fear of litigation that drove the EPs to continue to perform testing for PE on patients in whom that testing was not recommended. However, unnecessary testing also carries legal risks.

“If someone had a bad outcome associated with testing, and it was determined that this testing was unnecessary, there would seem to be liability for the physician who ordered this testing,” Madsen offers.

Additionally, the diagnosis of PE carries with it the need for long-term anticoagulation and the potential for adverse events associated with this. If the testing that led to that diagnosis was unnecessary, and the patient suffered an adverse outcome from the anticoagulation, there is potential liability, Madsen says.

“We are seeing more recommendations that physicians not perform testing, whether this be in the ED or in primary care screening practices,” Madsen notes.


  1. Vinson DR, Ballard DW, Huang J, et al. Outpatient management of emergency department patients with acute pulmonary embolism: Variation, patient characteristics, and outcomes. Ann Emerg Med 2018;72:62-72.e3.
  2. Vinson DR, Berman DA. Outpatient treatment of deep venous thrombosis: A clinical care pathway managed by the emergency department. Ann Emerg Med 2001;37:251-258.
  3. Vinson DR, Zehtabchi S, Yealy DM. Can selected patients with newly diagnosed pulmonary embolism be safely treated without hospitalization? A systematic review. Ann Emerg Med 2012;60:651-662 e4.
  4. Vinson DR, Ballard DW, Huang J, et al. Timing of discharge follow-up for acute pulmonary embolism: Retrospective cohort study. West J Emerg Med 2015;16:55-61.
  5. Vinson DR, Ballard DW, Mark DG, et al. Risk stratifying emergency department patients with acute pulmonary embolism: Does the simplified pulmonary embolism severity index perform as well as the original? Thromb Res 2016;148:1-8.
  6. Erkens PM, Gandara E, Wells P, et al. Safety of outpatient treatment in acute pulmonary embolism. J Thromb Haemost 2010;8:2412-2417.
  7. Buchanan I, Teeples T, Carlson M, et al. Pulmonary embolism testing among emergency department patients who are pulmonary embolism rule-out criteria negative. Acad Emerg Med 2017;24:1369-1376.


  • David Vinson, MD, Department of Emergency Medicine, Kaiser Permanente Medical Centers, Roseville and Sacramento; Co-chair, Kaiser Permanente Clinical Research in Emergency Services & Treatments Network. Email: drvinson@ucdavis.edu.