Figure 1: In late 2021, the Penn Lung Rescue mobile EMCO team transported an ECMO-dependent postpartum patient from Florida to the Hospital of the University of Pennsylvania, where she was converted to Oxy-RVAD therapy.
The Penn Lung Rescue Program provides mobile extracorporeal membrane oxygenation (ECMO) and other advanced therapies to critically ill patients throughout the Philadelphia region, as well as to hospitals outside the region in need.
Since its inception in 2014, the Lung Rescue mobile ECMO Program has taken part in the transport of almost 700 patients. The survival rate for mobile venovenous (VV) ECMO at Penn Lung has exceeded the Extracorporeal Life Support Organization (ELSO) average since the program began, including the pandemic years 2020-2022. ELSO is an international group that tracks ECMO patients.
As advocates for positive outcomes, the Penn Lung Rescue team has established and implemented clinical criteria for mobile ECMO, including safety protocols for cannulation, intubation, and imaging, and standards for mobile transport staffing and faculty.
The Program's mission also includes collaboration with other specialities — cardiac surgery, critical care anesthesiology, pulmonology, cardiology, infectious disease, and palliative care — and the establishment of sound inter-hospital communication, both critical to the management of mobile ECMO patients.
About ECMO
ECMO is a cardiopulmonary support system that draws blood from the vascular system and circulates it via an extracorporeal pump to an oxygenator, where the blood is infused with oxygen and CO2 is removed.
ECMO has two configurations. VV-ECMO, which extracts blood from the vena cava or right atrium and returns it to the right atrium, is used exclusively for respiratory support. Venoarterial (VA) ECMO draws blood from the right atrium and returns it to the arterial system, thus bypassing the heart and lungs, to provide both respiratory and hemodynamic support, much like a heart-lung bypass machine. The majority of patients transported by the Penn Lung Rescue mobile unit require only respiratory support; most receive VV-ECMO.
The indications for ECMO include cardiac failure and acute respiratory failure due to acute respiratory distress syndrome (ARDS), pneumonia, trauma, or post-transplantation primary graft failure refractory to optimal mechanical ventilation and medical therapy. Both indications are complicated by their inciting conditions or events and a patient's pre-existing comorbidities.
ECMO During the COVID Pandemic
The use and distribution of ECMO increased during the COVID pandemic, largely because ARDS is a principal cause of death in COVID, and because the use of prolonged mechanical ventilation (a requisite for seriously ill COVID patients) is a major cause of lung injury. By the end of 2020, the number of patients served by Penn Lung Rescue leaped 18% over 2019.
COVID introduced a new and entirely unanticipated series of concerns for the institution of ECMO, particularly for individuals with pre-existing morbidities. COVID is associated with coagulopathies originating in circulating micro- and macro thrombi and affecting multiple organ systems, including the heart, liver, kidney and lungs. According to ELSO, more than 14,846 adult patients with confirmed COVID were placed on ECMO in the US between the winter of 2020 and late 2022. [1, 2]
The COVID/ECMO population recorded by ELSO included patients with cancer (2%), immunocompromised conditions (5%), diabetes (26%), and pre-existing heart or lung disease (8%). Five percent of patients, moreover, were women in pregnancy or the peripartum, a population for whom respiratory failure is a major risk for morbidity and mortality, and for whom COVID presents an especially dire prognosis. [3]
References:
- Lorusso R, Whitman G, Milojevic M, et al. 2020 EACTS/ELSO/STS/AATS expert consensus on post-cardiotomy extracorporeal life support in adult patients. J Thorac Cardiovasc Surg 2021;161:1287-1331.
- ELSO Live Registry dashboard of ECMO Patient Data: Full COVID Registry. At: https://www.elso.org/registry/fullcovid-19registrydashboard.aspx
- Metz TD, Clifton RG, Hughes BL, et al. Association of SARS-CoV-2 Infection with Serious Maternal Morbidity and Mortality from Obstetric Complications. JAMA 2022;327:1-12.
Case Study
Mrs. K, a healthy thirty-three-year-old woman, gave birth to her first child in early August 2021 at a community hospital near Orlando, FL. The delivery was uncomplicated, and she and her infant went home two days later to recover.
Soon thereafter, Mrs. K developed the symptoms of COVID-19, which was confirmed by laboratory testing. Given the possibility of disease transmission, her family assumed the care of her child. Mrs. K was stable for twelve days, then experienced an abrupt and escalating dyspnea, and was taken to a local ER. Here, her oxygen saturation by pulse oximetry was found to be 92%, and a diagnosis of acute respiratory distress syndrome (ARDS) confirmed. Mrs. K was sedated and moved to the hospital ICU, and subsequently intubated and placed on a ventilator.
Over the next two weeks, Mrs. K was transferred first to a regional medical center in Orlando, then, as her condition progressively worsened, to a third hospital, where she was considered for VV-ECMO support. At this time, however, the US was in a severe, COVID-induced resource restriction, limiting access to ECMO support.
ECMO, Pregnancy, and COVID
The hemodynamics and blood constitution of women in the peripartum present unique challenges for ECMO therapy. These risks are compounded by COVID-induced ARDS. Mrs. K experienced further complications soon after her arrival at the third hospital, leading to a search for a program better able to address her ensuing issues. In the following days, more than 30 hospitals chose not to admit her or offer her ECMO care.
Finally, in early September, Mrs. K, now in a medically induced coma, was accepted by Penn Medicine and the Penn Lung Rescue Program. Later that day, Drs. Usman, Spelde, Vernick, and Gutsche coordinated her care from Orlando. Placed on VV-ECMO at the originating hospital, she was taken via fixed wing jet to Philadelphia, almost 1,000 miles away, and transported to the Hospital of the University of Pennsylvania.
On arrival at Penn Medicine, Mrs. K had evidence of RV dysfunction and elevated pulmonary pressures, as well as indicators of renal and hepatic failure. The Lung Rescue team made the critical decision to change her ECMO support strategy. From the transport VV-ECMO platform, she was taken to a hybrid operating room where an Oxy-RVAD was introduced to support her right ventricular function (VV-ECMO does not provide RV support). Oxy-RVAD devices combine a pump to draw blood directly from the RV into an oxygenator, from which the blood is returned to the pulmonary artery.
Because Mrs. K was ECMO dependent, even momentary cessation of ECMO support could prompt respiratory and cardiac arrest. To convert her to the Oxy-RVAD platform, therefore, the cardiac anesthesiologists and Lung Rescue Program team planned a highly coordinated effort that included a brief, controlled cardiac arrest. After stabilization on the Oxy-RVAD platform, Mrs. K was returned to the Penn Medicine Cardiothoracic ICU. There, the ICU team played a critical part in the management of her daily infusions, antibiotics, and nutritional support while the physical therapists and respiratory therapists monitored her for wounds and recovery of lung function and ventilator mechanics.
Figure 2: Mrs. K and family, November 2022.
Following a slow, but steady improvement, the Penn ICU team brought Mrs. K out of her coma while she remained on Oxy RVAD support. At her wakening, she was made aware that she had survived three hospitals transfers, a flight on ECMO from Florida to Philadelphia, and that her child was healthy and safe.
In the weeks thereafter, Mrs. K began a slow recovery to health. Her kidney and liver function stabilized. She began physical therapy to regain her core body strength, range of motion, and breathing strength. As she progressed, she had a temporary tracheostomy placed, and was eventually liberated from her ventilator. After 48 days of ECMO support her cannulas were removed. Soon thereafter, she was transferred back to a hospital in Florida to continue her physical therapy.
In all, Mrs. K spent 88 days on a ventilator and was hospitalized for a total of 106 days. Today, she remains independent of oxygen support, and has resumed the life she led before her hospitalization. She recently celebrated her son's first birthday with her husband and family.
About the Penn Lung Rescue Program
As one of the largest academic medical centers in the United States Penn Medicine has the critical resource to offer support to the most critical patients. Operating from Penn Presbyterian Medical center in Philadelphia, the Penn Lung Rescue Program is comprised of cardiologists, pulmonary anesthesiologists. critical care specialists and perfusionists who work in coordination with dedicated staff for ground or air transport to the patient's location and back to Penn Medicine. The Program's single mission is to provide VV-ECMO as a bridge to recovery for patients with reversible lung failure.
Penn Presbyterian Medical Center
Department of Anesthesiology and Critical Care
51 N 39th Street
Philadelphia, PA 19104