Implementation of Extracorporeal Membrane Oxygenation Without On-Site Cardiac Surgery or Perfusion Support: A Tale of Two County Hospitals

Authors: Kyle S. Bilodeau, Jenelle Badulak, Eileen Bulger, Barclay Stewart, Samuel P. Mandell, Mark Taylor, Anna Condella, Michelle D. Carlson, Louis P. Kohl, Nicholas S. Simpson, Beth Heather, Matthew E. Prekker, Nicholas J. Johnson

Abstract

Patients with refractory respiratory and cardiac failure may present to noncardiac surgery centers. Prior studies have demonstrated that acute care surgeons, intensivists, and emergency medicine physicians can safely cannulate and manage patients receiving extracorporeal membrane oxygenation (ECMO). Harborview Medical Center (Harborview) and Hennepin County Medical Center (Hennepin) are both urban, county-owned, level 1 trauma centers that implemented ECMO without direct, on-site cardiac surgery or perfusion support. Both centers 1) use an ECMO specialist model staffed by specially trained nurses and respiratory therapists and 2) developed comparable training curricula for ECMO specialists, intensivists, surgeons, and trainees. Each program began with venovenous ECMO to provide support for refractory hypoxemic respiratory failure and subsequently expanded to venoarterial ECMO support. The coronavirus disease 2019 (COVID-19) pandemic created an impetus for restructuring, with each program creating a consulting service to facilitate ECMO delivery across multiple intensive care units (ICUs) and to promote fellow and resident training and experience. Both Harborview and Hennepin, urban county hospitals 1,700 miles apart in the United States, independently implemented and operate adult ECMO programs without involvement from cardiovascular surgery or perfusion services. This experience further supports the role of ECMO specialists in the delivery of extracorporeal life support.

Patients with both acute and refractory respiratory and cardiac failure may not present to tertiary or quaternary care hospitals, including a subset of patients with indications for venoarterial (VA) extracorporeal membrane oxygenation (ECMO) who do not meet an indication for acute surgical intervention. Data suggest that noncardiac surgeons, such as acute care surgeons, intensivists, and emergency medicine (EM) physicians, can safely cannulate and manage patients receiving ECMO for a variety of indications^1–4^; however, few studies describe ECMO programs that have been established or maintained without the direct support of cardiac surgery and perfusion services. Additionally, characterization of the primary operator performing cannulation and critical care management is frequently not captured or reported with fidelity in existing literature, and thus the degree to which these ECMO programs are supported by cardiac surgery and perfusion services remain largely unknown.

Both Harborview and Hennepin created ECMO programs to address the needs of adult respiratory and cardiac failure patients at county-owned, level 1 trauma centers without routine on-site cardiac surgery or perfusion involvement. This narrative review will provide an overview of program configuration, training, and lessons learned from the evolution of each program.

Trauma Center Characteristics and Settings

Harborview Medical Center (Harborview) in Seattle, Washington and Hennepin County Medical Center (Hennepin) in Minneapolis, Minnesota are level 1 adult and pediatric trauma and burn centers that serve their respective communities as urban safety net hospitals and regionally as referral centers. Center characteristics are outlined in Table 1, with both institutions reporting similar overall acute care and critical care capacities.

Harborview is managed under contract by the University of Washington and serves as a core training site for multiple residency programs within the University of Washington (UW) School of Medicine and other area training programs. Harborview supports critical care fellowship training programs in trauma/burn surgery, pulmonology, emergency medicine, and anesthesiology. Intensivists from all of these services work collaboratively to support the trauma/surgical, burn, medical, neurosciences, pediatric, and cardiac ICUs. Trauma surgeons and medical ICU (MICU) attendings remain in house 24/7. Elective cardiac surgery is not performed at Harborview nor are clinical perfusionists available on-site. Hennepin is a primary teaching site for the University of Minnesota Medical School and sponsors its own residency training programs in Emergency Medicine, Internal Medicine, and General Surgery, among others, as well as a medical critical care fellowship. The trauma/surgical and burn ICUs at Hennepin are staffed by critical care surgeons who are in house 24/7, while the MICU is staffed by pulmonary and critical care attendings who take overnight call from home. Hennepin does offer select cardiac surgical procedures such as coronary artery bypass grafting performed by cardiac surgeons whose primary practice is based at the University of Minnesota, with cardiac surgery supported at Hennepin by a contracted perfusionist service. Cardiac surgeons facilitated the development of Hennepin’s ECMO program in 2015 but are no longer involved in clinical or program operations.

Both hospitals have on-site cardiac catheterization laboratories capable of 24/7 percutaneous coronary intervention (PCI) while urgent cardiac surgical emergencies (e.g., valvular lesions, cardiogenic shock requiring durable mechanical support, and Stanford type A aortic dissection) management require transport to each center’s affiliated university hospital.

ECMO Program Genesis and Timelines

Hennepin had provided ECMO on a noncontinuous basis over the past 20 years, but previously its use depended on the availability of cardiac surgeons to cannulate and co-manage these patients and contracted perfusionists to assist with circuit management. During these years, ICU nurses had training and exposure to ECMO, primarily in the surgical intensive care unit (SICU). Harborview had no prior ECMO experience but did have the ability to initiate cardiopulmonary bypass in the operating room for trauma patients with cardiac or proximal great vessel injury with cardiac surgery and perfusionist support from the University of Washington Medical Center. Before 2015, neither program had staffing or durable infrastructure to provide ECMO support on a routine basis. The timelines for program development are depicted in Figure 1. Both institutions developed formal ECMO programs between 2015 and 2016 to provide venovenous (VV) ECMO to select critically ill and injured patients with refractory respiratory failure and limited venoarterial (VA) ECMO indications, and later evolved to provide more extensive VA ECMO and extracorporeal CPR (ECPR). ECPR programs were launched in 2018; however, both programs suspended ECPR cannulations due to resource and staffing constraints during coronavirus disease 2019 (COVID-19).

ECMO Personnel

ECMO Specialists

An ECMO specialist model was independently and organically developed at both institutions based on prior nonperfusionist models.^5,6^ Hennepin utilized registered nurses (RNs) while Harborview trained both RNs and respiratory therapists (RTs). Specialists were recruited from existing ICU RNs and RTs on a voluntary basis and were required to successfully complete the training programs outlined below before consideration for bedside ECMO care. At Hennepin, specialists additionally were required to have 2 years of current, full-time ICU experience, pass a prerequisite critical care examination, and be selected through an interview panel. Specialist responsibilities include circuit priming, assisting a physician in cannulation and ECMO initiation, and bedside circuit management. At Harborview, each patient is assigned both an ECMO specialist and a dedicated ICU nurse in a 1 model. At Hennepin, an ECMO nurse specialist is assigned 1 to an ECMO patient, serving a dual role of bedside care and circuit management.

ECMO Physicians and Consult Service Evolution

At Harborview, the ECMO program was initially led by trauma/critical care surgeons who performed all cannulations and managed patients on the trauma/surgical ICU service alongside critical care fellows, and later was expanded to include emergency medicine-critical care physicians (EM). Patients with a primary medical etiology for their respiratory or cardiac failure are managed in the MICU, whereas patients with trauma or surgical primary problems remain on the trauma/surgical ICU service. Due to the increased number of patients requiring ECMO for refractory hypoxemia secondary to COVID-19 pneumonia, the Harborview program has evolved to a consult service. Current staffing for the consult service is a single attending (intensivist with training in trauma, EM, anesthetic, or pulmonary) and a critical care fellow. The ECMO consult attending is present for daily rounds and provides oversight of all ECMO-related care during the day, and then takes call at home overnight. The critical care fellow role is split between a dedicated ECMO fellow during the day and a covering trauma/critical care fellow who remains in-hospital overnight with other duties.

The Hennepin ECMO program is staffed by pulmonary-critical care physicians and critical care fellows. Cardiologists consult on all VA ECMO patients. Since the majority of ECMO patients are on the MICU service, Hennepin has not had to create a dedicated consult service but instead created a “flex coverage” where medical critical care faculty and fellows manage ECMO, in a consultative model, in patients with polytrauma or burns that are housed in the SICU and Burn Unit.

ECMO Training Curriculum

ECMO Specialist Training

The curricula for each program’s ECMO specialist training are outlined in Supplemental Figure 1a (http://links.lww.com/ASAIO/A939) and Supplemental Figure 1b (http://links.lww.com/ASAIO/A940). Courses are performed on site, ranging from 32 to 40 hours and include didactics, hands-on simulation, and competency testing. At both institutions, didactics focus on the fundamentals of ECMO operation and cardiopulmonary physiology, ECMO policy and procedures (including indications and contraindications, complications, anticoagulation, patient, and circuit monitoring, and troubleshooting circuit emergencies). Hands-on simulation focuses on learning how to operate the ECMO console and circuit, daily management, and recognizing and responding to ECMO emergencies. Both institutions have incorporated the Maquet Cardiohelp (Getinge, Göteborg, Sweden) into training and clinical use. The integrated platform and user interface of the Cardiohelp system was found to be more conducive to bedside management by RN or RT specialists. Following successful completion of the ECMO specialist curriculum, both institutions track patient care hours. Ongoing training for knowledge base and skill maintenance is provided through didactics, case review, simulation, competency checks and an annual written examination.

Faculty and Fellow Training

Before launching the Harborview program, the program director and nursing leadership attended a comprehensive Extracorporeal Life Support (ECLS) training program at the University of Michigan and visited other ECMO centers to learn the logistics of establishing a program. Upon initiation of the program, an internal 8-hour didactic session was provided for all faculty and a director of ECMO education appointed to oversee all curricula and education. A total of five of the 12 faculty were also supported to attend the Extracorporeal Life Support Organization (ELSO) 4-day training course for additional training. An asynchronous online curriculum (www.corecmo.com) was developed to complement in-person didactic training. This online curriculum is currently combined with a 3.5 hour introductory in-person simulation training session, which focuses on daily patient management and circuit emergencies. All new faculty and fellows complete these sessions. Advanced ECMO practitioners completed an additional simulation session encompassing circuit emergencies. A supplementary cannulation session, utilizing an ECMO-cannula compatible vascular access mannequin, was created to train cannulating physicians. With the creation of the ECMO consult service, a 1-month ECMO elective is available to critical fellows for in-depth training in patient selection, cannulation, and management.

Upon initiation of the Hennepin program, an internal 1.5-day ECMO management course was designed and delivered to faculty and fellows. Maintenance and expansion of skills in ECMO management is accomplished with half-day didactic and simulation sessions, held quarterly, where ECMO nurse specialists and physicians train together on management challenges and circuit emergencies. When the program expanded to include regular initiation of VA ECMO outside of the operating room, nurse and physician leadership attended a 2-day ECLS training program focused on VA ECMO cannulation and stabilization in a non-Operating Room setting (https://reanimateconference.com/). Following this conference, additional training in management of VA ECMO was incorporated into quarterly training curricula. A high-fidelity mannequin, altered to simulate vascular access for ECMO cannulation, is used for maintenance of procedural skills for cannulating physicians at Hennepin and in “wet lab” scenarios for ECMO specialists. A program website with public- and private-facing components was created and includes resources for members of the ECMO team (www.hennepinecmo.com).

For assessment, novice trainees completed a pre- and post-curriculum knowledge assessment and received course evaluations completed by attending physicians to assess minimal competency in caring for the patient on ECMO. At Harborview, physicians and specialists who successfully complete all of the aforementioned training modules and have logged sufficient clinical hours are eligible to sit for the ELSO Adult ECMO Practitioner Certification (E-AEC) examination.

Patient Selection for ECMO

Indications and Contraindications

Indications for both VV and VA ECMO are summarized in Table 2. The general approach to patient selection for extracorporeal support is similar between Harborview and Hennepin. Neither program currently utilizes scoring systems, as it was collectively felt the genesis of such scores were more appropriate for aiding in prognosis rather than guiding patient selection. Contraindications similarly emphasize exclusion of patients with premorbid medical conditions that are not reversible and life-limiting (e.g., metastatic malignancy, end-stage organ system disease without transplant candidacy, or devastating neurologic injury), advanced aged (Harborview does not have specified age criteria, Hennepin specifies >75 years old), and active Do Not Resuscitate status. The Harborview and Hennepin teams will manage VV ECMO patients without anticoagulation if needed, which has allowed use of this rescue therapy in select trauma and medical patients.

Criteria Used for ECMO Referral

Both Harborview and Hennepin have developed protocolized referral and transfer guidelines for VV and VA, respectively. Patients considered for inter-facility transfer to receive VV or VA ECMO meet the indication criteria from Table 2 and do not have any of the relative or absolute center-specific contraindications. If patients have not already been cannulated at the outside facility, then safety for transport is determined by defining whether critical hypoxemia with Saturation of Peripheral Oxygen <80% on Fraction of Inspired Oxygen >90%, especially with movement or repositioning, or severe acidemia with pH <7.1 are present. If potential referrals are found to have critical hypoxemia or severe acidemia, then discussion of cannulation before transfer is made by the ECMO attending. Patients are preferentially considered for VV transfer within the first 7–10 days of their need for maximal ventilatory support. Lastly, both centers emphasize that even if a patient is accepted for transfer, there is no guarantee of ECMO as it is dependent upon the patient condition upon arrival, status updates before transport, and ECMO capacity at either of the accepting facilities.

ECMO Patient Characteristics and Outcomes

Since program inception to 2021, total cannulations for VV, VA, and ECPR at Harborview and Hennepin are 160 and 156, respectively. Baseline patient characteristics are listed in Table 1, with the majority of patients noted to be male and aged 18–60 years. Indications for cannulation and outcomes from each program are listed in Table 3, with the indications noted to be proportionally similar between institutions. Total VV and VA ECMO runs and overall survival to hospital discharge are depicted in Figure 2, A and B, with both institutions demonstrating similar trends over time with respect to both ECMO volume and overall survival. The noted decrease in survival to discharge at Harborview likely occurred during the “Delta” wave of the COVID pandemic, as other centers additionally reported worse outcomes during this time period.^7^

Key Lessons and Programmatic Decisions

VV, VA, and ECPR

Essential lessons from each phase of ECMO implementation are summarized in Table 4. Both programs leveraged a multidisciplinary approach to growth, with proactive identification of key staff to enable opportunity for collaborative program development and adequate training. Adding faculty across multiple departments during program conceptualization was mutually felt to improve stakeholder buy-in and provide pivotal cross-departmental collaboration essential for successful implementation and growth of nascent ECMO programs. Focusing on implementation within a single department/geographic area in the hospital was found to improve teaching and training through structured daily multidisciplinary rounds, coordination of bedside diagnostics and procedures, overall quality of care, and fidelity of data collection at both Harborview and Hennepin. Both programs felt that focusing program implementation in this way allowed for improved coordination across the various phases of ECMO activation, cannulation, ICU management, and weaning.^8,9^ Establishment of a dedicated ECMO program coordinator facilitated root causes analyses and provided oversight for all quality improvement.

Key changes to the original programs during ECPR expansion included a dedicated ECMO paging system, where an ECMO physician and support team were immediately deployable to the emergency department (ED) or cardiac catheterization laboratory. Inclusion of Emergency Medical Services (EMS) and EM medical directors during ECPR program conception are strongly encouraged. EMS leaders and personnel must adapt to timely identification of refractory cardiac arrest, then rapidly notify and transport to an ECPR center to minimize the time interval from collapse to the initiation of VA ECMO support (a key marker for quality and outcome). Both centers created and maintain pre-primed ECMO circuits and aeromedical kits that can be deployed for rapid cannulation and facilitate timely transport.

Both centers utilized existing consultant services and relationships with cardiology, cardiac surgery, and vascular surgery to support decisions about recovery, ventricular venting, mechanical circulatory support (MCS), transfer, and decannulation. At centers with cardiac surgery support, partnership with cardiac surgeons is ideal; however, centers without cardiac surgery should develop criteria for consultation and transfer. Additionally, a relationship with vascular surgery should be established for difficult access or limb complications. Those patients who required consideration for durable MCS, transplant candidacy, or advanced cardiac surgical needs were transferred to a university setting on a case-by-case basis after consultation with cardiology or cardiac surgery.

Creation of Transport and Retrieval System

Programmatic changes and considerations during expansion of an ECMO program to include transport and retrieval capabilities are listed in Table 5. Existing aeromedical partnerships were utilized in both regions. Dedicated ECMO transfer acceptance checklists, standardized equipment kits, transport guidelines, and medical control contact information were updated and added to each program’s ECMO resources. Training was accomplished via simulation sessions with both aircraft and ground ambulance in partnership with aeromedical staff. Additionally, if performing out-of-state transfers, it is necessary to ensure proper licensing and credentialing of all providers or develop a dedicated retrieval system to circumvent relevant licensing requirements.

Impact of the COVID-19 Pandemic

COVID-19 increased ECMO resource utilization and decreased available staffing across both institutions, with key adaptations listed in Table 6. Harborview utilized shared isolation rooms to cohort COVID positive ECMO patients with a shared ECMO specialist to meet the increased ECMO demands. Both programs made changes to their existing transfer program, where acceptance of any COVID positive patient for ECMO continuation or consideration was made by both an intensivist staffing the COVID ICU and the attending physician on the ECMO consultant service. Additionally, each center created a consortium to facilitate tracking of state-wide ECMO resources and collaboration with other adult ECMO centers to coordinate resource utilization and availability. Hennepin collaborated with other ECMO centers in Minnesota to adopt a uniform eligibility criteria for VV ECMO candidacy throughout the pandemic, adding consistency and equity to the allocation of a scarce resource.^10^

Each program restructured their existing transfer program to focus on retrieval of cannulated patients to decrease the burden on staffing deployments and improve transfer efficiency. Lastly, the increased burden on ECMO specialists and providers was noted to create significant moral distress among team members, and multidisciplinary discussions were utilized to provide staff opportunities to share concerns for futility and improve goals of care discussions among palliative care consultants, staff and families.

Conclusions

ECMO programs at Harborview and Hennepin exist without the immediate availability of cardiac surgery or perfusion services to address the needs of adult patients with fulminant respiratory or cardiac failure. Existing literature often fails to describe the primary operator performing ECMO cannulation and personnel involved in longitudinal critical care management of the adult ECMO patient. While other reports of noncardiac surgery physicians and ECMO specialists do exist, the extent of support received by cardiac surgeons, perfusionists, and the methodologies of programmatic implementation and maintenance are lacking.^1–4^

This article is, to our knowledge, the first to fully characterize the genesis, implementation, and system-level coordination required to create an ECMO program staffed by intensivists, RN’s, and RT’s without direct support by cardiac surgery or perfusion services. Both programs independently developed comparable training curricula for ECMO specialists, intensivists, surgeons, and trainees, and incorporated structured, multidisciplinary rounds initially within a single location to facilitate education and quality of care. Success with initial implementation allowed for expansion of both programs to include ECPR; however, the COVID-19 pandemic created an impetus for restructuring, with suspension of ECPR programs for resource preservation and creation of an ECMO consultant service to facilitate ECMO care across multiple ICU’s, as well as coordinate transfer and retrieval of potential ECMO candidates.

Successful implementation required clinician, staff, and administrative support to fully operationalize both ECMO programs, and to ensure adequate resources and capital for programmatic success and maintenance.^11^ Key program components included early incorporation of a multidisciplinary team of ECMO physicians and surgeons, intensivists, emergency physicians, RN’s, and RT’s to lead program development and implementation at each respective institution. Relationships with cardiology, vascular surgeons, and advanced cardiac surgical centers also proved pivotal to ensure access to consultation and facilitate transfer for durable support.

Both programs have independently demonstrated the feasibility of establishing and maintaining an ECMO program at public hospitals utilizing the RN and RT ECMO specialist models, with overall survival rates comparable to international registries.^12^ Each institution additionally has further demonstrated comparable outcomes during program expansion and restructuring to meet the demands secondary to COVID-19. The experiences of Harborview and Hennepin further support the role of ECMO specialists in the delivery of ECMO care without necessitating direct involvement from cardiac surgery or perfusion services.

Supplementary Material