Pulmonary Embolism Response Teams

Authors: Nektarios Konstantinopoulos, MD (Emergency Medicine Resident, University of Vermont Medical Center); Michael Sheeser, MD (@MichaelSheeser, Assistant Professor of Emergency Medicine, University of Vermont Medical Center); Skyler Lentz, MD (@skylerlentz, Assistant Professor of Emergency Medicine and Medicine, University of Vermont Medical Center) // Reviewed by: Andrew Grock, MD (Assistant Professor of Emergency Medicine at the David Geffen School of Medicine, Faculty Physician at the Greater Los Angeles VA Hospital); Alex Koyfman, MD (@EMHighAK); Brit Long, MD (@long_brit)

Case:

A 27-year-old female presents with three days of lightheadedness, chest pressure and shortness of breath that acutely worsened an hour prior to arrival. Initial vital signs: heart rate 118/min, BP 102/59 mmHg, respiratory rate 34/min, pulse oximetry of 91% on room air, and a temperature of 37.6. Her past surgical history is relevant for a trimalleolar fracture repair 3 weeks ago. On exam she appears anxious, with respiratory distress, although she is well-perfused. Her right leg is in a cast. You place her on supplemental oxygen. Given your high suspicion for pulmonary embolism, you order a CT pulmonary angiography (CTPA) with an ECG and laboratory studies. Prior to her CT a bedside echocardiogram shows a dilated right ventricle without bowing of the septum and a plethoric IVC. CTPA confirms multiple bilateral lobar and segmental pulmonary emboli with evidence of right heart strain. Her labs are notable for troponin of 0.17 ng/mL (normal < 0.034 ng/mL), NT-pro-BNP of 1760 pg/mL, and a lactate of 2.4 mmol/L. You correctly classify this presentation as a submassive, or an intermediate high-risk PE at high risk of hemodynamic decompensation and begin to weigh the risks and benefits of the treatment options: heparin alone, systemic alteplase (full or half dose), intra-arterial thrombolytics, or thrombectomy. When the nausea from thinking about having to make so many phone calls passes, you separately consult pulmonary, MICU, and IR to discuss treatment options. After instructing your 3^rd consult to discuss treatment options with the 2^nd, the patient’s nurse interrupts to report the patient is decompensating. How could a PE response team help?

What is a Pulmonary Embolism Response Team (PERT)? 

A pulmonary embolism response team (PERT) has been defined by the PERT Consortium¹ as an institutionally based multidisciplinary team that meets the following criteria:

• Ability to rapidly assess and provide treatment for patients with acute pulmonary embolism
• A formal mechanism to exercise a full range of medical, surgical, and endovascular therapies
• Provide appropriate multidisciplinary follow-up of patients
• If feasible, willingness to collect, evaluate, and share data regarding the effectiveness of treatment rendered.

Origins of the PE Response Team:

Pulmonary embolism is the third most common cause of cardiovascular death² and the number one cause of preventable in-hospital death³. The pulmonary embolism response team is a concept founded and implemented first at Massachusetts General Hospital (MGH) in 2012⁴. This idea was predicated on several decades of the development of clinical teams in the management of acute conditions with trauma teams in the 1980’s, through STEMI and Stroke teams, and most recently with inpatient rapid response teams. The development of PERTs was initiated primarily because the arena of acute pulmonary embolism management contains multiple therapeutic interventions across diverse specialties without robust evidence to guide clinical decision-making. Further complicating the care of acute PE management and necessitating the development of PERTs was the potential for abrupt decompensation in PE patients, particularly in intermediate high-risk (i.e., submassive) group.

PERT Structure and Membership:

PERT structure and functions vary considerably by institution. With the aim of rapid assessment, risk stratification, and definitive therapeutic intervention in a multidisciplinary context, institutions have constructed a multiplicity of solutions to meet these aims.

Since their inception, PERTs have been multidisciplinary. The underlying goal is to rapidly develop a consensus decision on management of the high-risk acute PE patient. Rather than the traditional consultation paradigm where formal recommendations may be delayed, fragmented, and possibly contradictory, the ultimate goal of PERT is to expedite a clear consensus decision on management in the context of multiple therapeutic options. While the exact specialties represented on a PERT will display institutional variability, there is usually a core group of specialties represented.

In one survey of PERTs, the most commonly included specialties were: Pulmonary/Critical Care, Interventional Cardiology, and Emergency Medicine, then followed by Cardiothoracic Surgery, Interventional Radiology, Non-interventional Cardiology, Hematology, and Vascular Medicine^5,6. Various institutions, depending on capabilities, include additional members. Including clinical pharmacists is also recommended to assist in rapid assessment of medication dosing, contraindications (such as bleeding risk), and drug-drug interactions⁷. Pharmacist representation was not merely associated with the facilitation of care, notably reduced time to anticoagulation, but had significant impacts on patient care, primarily the reduction in major bleeding events in patients under PERT care that involved pharmacy representation⁸. In more advanced settings, particularly those with ECMO capability and experience, PERTs often include cardiac anesthesiologists⁷. Additional suggestions from the PERT community on member representation include nursing, research coordination, administration, and social work⁹.

Emergency Physicians as PERT Members: 

It is essential that ED physicians not view PERTs as a consulting group of clinicians with a specialist-driven approach to management of the patient; ideally emergency physicians comprise a core component of PERTs, as up to 60% of PERT activations originate in the Emergency Department (ED)¹⁰. Additionally, each PERT activation helps to shape the culture and practice style at each institution. Thus, representation from emergency physicians is important in developing institutional standards and continuity in the management of pulmonary emboli. At some institutions, the emergency physician is not only the activator of the PERT but also drives the process forward and activates additional members of the team as deemed necessary¹¹. If these features are to be characteristics of the emergency physician’s role in a PERT, then they must possess expertise in the management of PE outside of the context of the ED. Emergency physicians also possess a unique level of comfort with multidisciplinary engagement and can provide a degree of neutrality when forming a consensus, in part because emergency physicians do not perform procedural interventions in the context of PE⁷. Given the acuity associated with PE, transfer may be necessary. It is possible that pre-hospital providers could also assist in PERT activations, though caution is needed to maintain an appropriate differential diagnosis upon arrival to the ED. This is an area where emergency medicine could leverage its experience to help contribute to the PERT process.

What can PERTS assist with? 

In the context of acute pulmonary embolism, PERTs are designed to provide clarity in the context of therapeutic ambiguity. They are not designed, and never were intended, to supplant the emergency physician’s clinical judgement. Within certain patient populations, there are clear indications for therapy. Patients with a massive PE, presenting with sustained hypotension, have high rates of mortality; systemic thrombolytic therapy is recommended if not contraindicated in these cases¹². Absolute contraindications include: prior intracranial hemorrhage, known structural cerebral vascular lesion, known malignant intracranial neoplasm, ischemic stroke within three months, suspected aortic dissection, active bleeding or bleeding diathesis (excluding menses), and significant closed-head trauma or facial trauma within three months. The PERT should be activated in these cases to provide essential guidance regarding alternative treatments in those patients with contraindications to systemic thrombolysis or failure of initial thrombolysis. On the other end of the acuity spectrum, patients deemed low-risk, without management complexity, are often admitted, but they can be safely discharged and managed in the outpatient setting¹³. These do not typically require PERT activation.

A core role of PERTs is rapidly determining consensus recommendations where supporting evidence is limited, particularly in the context of intermediate risk (i.e., submassive) PE^14,15. The intermediate risk group is heterogeneous and often involve complex decision-making. These patients can be broken down further into “intermediate high” and “intermediate low” risk categories; those in the intermediate high-risk category have right ventricular strain and abnormal cardiac biomarkers (e.g., elevated troponin or BNP)¹². Those in the intermediate high-risk category may be considered for advanced therapies, in consultation with a PERT, such as thrombolysis or catheter directed treatments. PERT’s have also been utilized at particular institutions in low-risk PE patients whose complexity renders standard treatment inappropriate¹⁰. In fact, at MGH, the founding institution of PERT’s, approximately 20% of PERT activations were in low-risk PE patients. These patients tended to have significant comorbidities, had failed treatment, or had extensive clot burden¹⁶. Realistically, most PERTs are not designed for activation for low-risk PE; these patients will likely be discussed by the emergency physician with the hospitalist, hematology/oncology, or pulmonary consultants as needed. It must also be noted that the contrary is also true and that just because a patient has a high-risk PE, PERT activations are not mandatory¹⁶ and be managed in accordance with widely-accepted, evidence-based practices.

There are some additional roles of PERTs that are largely institutionally dependent and potentially overlooked. In a healthcare network, PERTs can be particularly useful because they enable the expertise of PERT members to be shared across various clinical delivery points. Theoretically, PERTs may be involved through telemedicine consults during the interfacility transfer process, not only to evaluate for the appropriateness of transfer, but to medically optimize patient care or begin therapy prior to transport. Perhaps one of the most overlooked benefits of PERT formation is ensuring that clinicians involved in the outpatient care of PE patients are involved in the decision-making regarding their acute management, ensuring effective continuity of care. PERTs can also be utilized to increase data collection in efforts to both augment research efforts and to facilitate the implementation of quality improvement measures⁵.

Do PERTS Make a Difference? 

PERTs are one of the more recent additions to the clinical teams model. Not surprisingly, at this time, definitive evidence is lacking in the academic literature about whether the PERT model provides clinically meaningful benefits in patient care. While publications from single institutions and other anecdotal accounts offer support for the benefit of this PERT model, the true impacts of PERT implementation remain unclear.

There is significant evidence that PERTs increase the rate of advanced procedures, specifically catheter-directed interventions^17,18. Regarding the effect on the rates of additional advanced procedures, the available evidence is limited and often contradictory. In one study, there was an increase in surgical embolectomy, a rare procedure in the context of PE, but a decrease in the placements of IVC filters¹⁸. This noted increase in the use of advanced procedures was also present in other studies, perhaps associated with the data demonstrating that PERT activations occur primarily in patients with intermediate risk PEs¹⁹. Despite the increase in advanced procedures with the implementation of PERT activations, this was not associated with an increase in cost²⁰. Reassuringly, PERT activations and the increased utilization of advanced procedures did not correlate with an increased rate of serious bleeding^18,19.

PERTs effect on mortality though remains unclear. Two studies failed to demonstrate a statistically significant reduction in mortality^17,19. In subgroup analysis, certain institutions may have significant mortality benefit from utilization of PERTs, whereas in other more robust systems with sophisticated management of PEs already in place, the benefits from PERTs may be more nuanced. In other studies, frank improvement in mortality was clearly demonstrated²⁰.

What, besides the clinical improvement of patients, do emergency physicians care about? A safe and appropriate disposition. While the literature regarding the relationship between PERTs and care in the ED is sparse, there is evidence that PERTs not only decrease the time to the initiation of anticoagulation in the ED but also decreased the time to appropriate disposition¹¹. A clear win.

Take Home Points:

• There are not sufficient data to support a standard of care in the management of intermediate risk PE and multiple therapeutic modalities exist.
• A Pulmonary Embolism Response Team is a multidisciplinary team that can rapidly assist in the management of acute PE.
• PERTs should generally be activated when there are contraindications to standard management or additional complexities in the care of the sick PE patient, such as with high intermediate risk PEs or in those with contraindications to usual therapies.
• There are conflicting data on whether PERT’s have a mortality benefit.
• It is beneficial for emergency physicians to be contributing members of PERTs, as PERT activations are most likely to occur in the ED.

Case Conclusion:

After the PERT activation by the Emergency physician, the Pulmonary-Critical Care fellow promptly evaluated the patient and presented the findings to the PERT. Concurrently, the patient had worsening hypoxemia, which led to a transition from nasal cannula to high-flow nasal cannula. Intermittently, she had recorded blood pressures in the low 90’s systolic. She became more anxious and appeared to deteriorate clinically. Though PERT members considered catheter-directed thrombolysis and multiple anticoagulation strategies, they decided to administer half dose thrombolytics after hearing of her worsening clinical status. After a short Intensive Care Unit admission, the patient was transferred to the floor and did well. She was asymptomatic 4 weeks later at her outpatient pulmonary embolism appointment.

References/Further Reading:

1. Rosovsky, R., Zhao, K., Sista, A., Rivera-Lebron, B., & Kabrhel, C. “Pulmonary Embolism Response Teams: Purpose, Evidence for Efficacy, and Future Research Directions.” Res Pract Thromb Haemostat. 2019; 9(3): 315-330.
2. Deitelzweig, S., Johnson, B., Lin, J., & Schulman, K. Prevalence of Clinical Venous Thromboembolism in the USA: Current Trends and Future Projections. Am J Hematol. 2011; 86(2): 217-220.
3. Heit, J., Sobell, J., Li, H., & Somner, S. The Incidence of Venous Thromboembolism Among Factor V Leiden Carriers: A Community-based Cohort Study. J Thromb Haemost. 2005; 3(2): 305-311.
4. Provias, T., Dudzinksi, D., Jaff, M., et al. “The Massachusetts General Hospital Pulmonary Embolism Response Team (MGH PERT): creation of a multidisciplinary program to improve care of patients with massive and submassive pulmonary embolism. Hosp Pract. 2014; 42(1): 31-37.
5. Barnes, G., Giri, J., Courtney, D., et al. “Nuts and Bolts of Running a Pulmonary Embolism Response Team: Results from and Organizational Survey of the National PERT Consortium Members. Hosp Pract (1995). 2017; 45(3): 76-80.
6. Barnes, G., Kabrhel, C., Courtney, D., et al. “Diversity in the Pulmonary Embolism Response Team Model: An Organizational Survey of the National PERT Consortium Members. Chest. 2016; 150(6): 1414-1417.
7. Kabrhel, C. “Achieving Multidisciplinary Collaboration for the Creation of a Pulmonary Embolism Response Team- Creating a Team of Rivals.” Semin Intervent Radiol. 2017; 34(1): 16-24.
8. Groth, C., Acquisito, N., Wright, C., et al. “Pharmacists as Members of an Interdisciplinary Pulmonary Embolism Response Team.” J Am Coll Clin Pharm. 2022; 5(4): 390-397.
9. Porres-Aguilar, M., Jimenez, D., Porres-Munoz, M., & Mukherjee, D. “Pulmonary Embolism Response Teams: Purpose, Evidence for Efficacy, and Future Directions.” Res Pract Thromb Haemost. 2019; 3(4): 769.
10. Kabrhel, C., Rosovksy, R., Channick, R., et al. “A Multidisciplinary Pulmonary Embolism Response Team: Initial 30-month Experience with a Novel Approach to Delivery of Care to Patients with Submassive and Massive Pulmonary Embolism.” Chest. 2016; 150(2): 384-393.
11. Wright, C., Elbadawi, A., Chen, Y., et al. “The Impact of a Pulmonary Embolism Response Team on the Efficiency of Patient Care in the Emergency Department.” J Thromb Thrombolysis. 2019; 48(2): 331-335.
12. Rivera-Lebron, B., McDaniel, M., et al. Diagnosis, Treatment and Follow Up of Acute Pulmonary Embolism: Consensus Practice from the PERT Consortium. Clin Appl Thromb Hemost. 2019; 2019 Jan-Dec;25:1076029619853037.doi: 10.1177/1076029619853037.
13. Peacock, F., Coleman C., Diercks D., et al. Emergency Department Discharge of Pulmonary Embolus Patients. Acad Emerg Med. 2018 Sep;25(9): 995-1003.
14. Cuomo, J., Arora V., Wilkins T. “Management of Acute Pulmonary Embolism with a Pulmonary Embolism Response Team.” J Am Board Fam Med. 2021; 34(2): 402-408.
15. Porres-Aguilar, M., Tapson V., Rivera-Lebron, B., Rali, P., et al. “Impact and Role of Pulmonary Embolism Response Teams in Venous Thromboembolism Associated with COVID-19.” J Investig Med. 2021; 69(6): 1153-1155.
16. Mortensen, C., Kramer, A., Schultz, J., et al. “Predicting Factors for Pulmonary Embolism Response Team Activation in a General Pulmonary Embolism Population.” J Thromb Thrombolysis. 2022; 53(2). 506-513.
17. Carroll, B., Beyer, S., Mehegan, T., et al. “Changes in Care for Acute Pulmonary Embolism Through a Multidisciplinary Pulmonary Embolism Response Team.” Am J Med. 2020; 133(11): 1313-1321.
18. Sosa D., Lehr A., Zhao H., et al. “Impact of Pulmonary Response Teams on Acute Pulmonary Embolism: A Systematic Review and Meta-Analysis. Eur Respir Rev. 2022; 31(165): 1-10.
19. Rosovsky, R., Chang, Y., Rosenfield, K., et al. “Changes in Treatment and Outcomes after Creation of a Pulmonary Embolism Response (PERT), a 10-year Analysis.” J Thromb Thrombolysis. 2019; 47(1): 31-40.
20. Myc, L., Solanki, J., Barros A., et al. “Adoption of a Dedicated Multidisciplinary Team is Associated with Improved Survival in Acute Pulmonary Embolism.” Respir Res. 2020; 21(1): 1-9.