Background: The public health emergency of Coronavirus Disease
2019 (COVID-19) caused by the novel coronavirus SARS-CoV-2 continues to
compromise global health and well-being. 1
Most patients will develop mild flu-like symptoms and quickly recover,
but a small subgroup of patients will progress to severe acute
respiratory failure, requiring admission to an intensive care unit for
increased level of support including mechanical ventilation and
ECMO.2
Recommendations for ECMO support for patients with severe pulmonary
failure related to SARS-CoV-2 infection is based on current developing
experiences and reports from previous epidemics.3, 4The World Health Organization (WHO) interim guidelines recommend the use
of ECMO to support eligible patients with COVID-19 related acute
respiratory distress syndrome (ARDS) in expert centers with sufficient
volumes to ensure clinical expertise. The FDA has recently approved the
application of ECMO and cardiopulmonary bypass circuits to support these
patients. 5
Mobile ECMO has developed in recent years at major ECMO programs around
the world as a way to facilitate implementation of ECMO support at
hospitals that lack this service, transfer patients on ECMO support from
one hospital with lesser resources to institutions with additional
capabilities to provide prolonged ECMO support, or provide additional
therapies to facilitate weaning off ECMO, and bridge patients to the
next therapy. We report a case of mobile ECMO, and discuss the potential
application in current SARS-CoV-2 pandemic.
Clinical Case: A 62 year old patient with history of exposure to
COVID-19+ patient during recent travel to England on February
27th, 2020 was admitted at a community hospital on
March 11th, 2020 with symptoms of persistent fever and
cough for 5 days accompanied by progressive shortness of breath in the
previous 24 hours. The patient rapidly progressed to advanced
respiratory failure requiring mechanical ventilator support within 12
hours of admission, and this failure required increased support settings
including prone ventilation. All were insufficient to provide adequate
oxygenation. Forty-eight hours after admission the patient was placed in
the prone position on pressure regulated volume control mechanical
ventilation with 100% FiO2, progressively hypoxemic, and in respiratory
acidosis (pH = 7.06, pCO2 = 82 mmHg, PaO2 = 59 mmHg).
Upon consultation to our program, the patient was discussed by a
multidisciplinary team and met clinical inclusion criteria including age
< 65 years, no major chronic comorbidities, and acute single
organ dysfunction limited to the lung. Hospital administration approved
deployment of our ECMO Team with the goal of instituting ECMO at the
referring hospital and transfer of the patient to our institution.
Emergency hospital privileges were provided to our cardiothoracic
surgeon for implantation of ECMO at the community hospital. Upon arrival
to referring hospital, after confirming the patient’s clinical condition
and laboratory results, final decision was made to proceed with
veno-venous ECMO support. The strategy for the procedure was discussed
with local SICU healthcare providers. The patient was turned back to the
supine position, and quickly prepped and draped, as oxygen saturation
declined < 88%. Cannulation was performed by implantation of
25Fr venous cannula in the right common femoral vein and a 20 Fr
arterial cannula in the right internal jugular vein, and both were
connected to the corresponding venous and arterial lines of the ECMO
circuit. A portable ECMO unit (CardioHelp System, Maquet Vascular
Systems, Merrimack, NH USA) was used to establish veno-venous ECMO (VV
ECMO) support at 3.5 L/min with 100% oxygen blend, resulting in
immediate improvement of blood pressure and pulse oximetry, allowing the
weaning of both vasopressor (norepinephrine) and mechanical ventilation.
Arterial blood gases confirmed improved gas exchange (pH = 7,32,
PCO2 = 48 mmHg, PaO2 = 153 mmHg).
Transfer of the patient involved a 60 miles trip via ambulance with 2
crew members, a physician, a nurse, and a perfusionist all wearing
personal protective equipment (PPE). Upon arrival, the patient was
transferred to a negative pressure room, and the portable ECMO unit was
switched to the routinely used ECMO unit (Rotaflow Console, Maquet
Cardiopulmonary AG, Rastatt, Germany).
The patient remained stable on VV ECMO and mechanical ventilation. He
remained with single organ dysfunction limited to the lungs,
progressively improved CXR and clinical examination, which lead to
weaning of ECMO at day 21, and extubation on day 25. Antiviral therapy
included a 5-day course of hydroxychloroquine and azithromycin, followed
by 10-day course of remdesivir. The patient developed pseudomonas
pneumonia, requiring 10 day course of cefepime. He continued to improve
clinically with two negative COVID-19 PCR results at day 30 and 31 of
hospital admission, and was discharged from the hospital 5 days later,
completing 10 days of IV cefepime for treatment of pseudomona aeruginosa
pneumonia.
Discussion: SARS-CoV-2 infection has quickly developed into a
pandemic affecting the population of over 200 countries. Health systems
around the globe are overwhelmed by an unprecedented number of patients
with advanced respiratory failure. The role of ECMO for selective
patients with advanced respiratory failure related to COVID-19 has been
recognized, but it is a highly specialized and resource intensive
therapy. International societies recommend provision of ECMO support by
specialized centers.6
Most experienced centers around the world have revised indications of
ECMO for patients presenting with COVID-19 related respiratory failure,
including more stringent inclusion criteria related to age (<
65 years) and the absence of chronic comorbidities or chronic organ
dysfunction. ECMO programs are also limiting mobile ECMO services in an
effort to decrease the risks to healthcare personnel and preserve
limited resources. Preliminary observations indicate that approximately
1% of patients hospitalized for COVID-19 might benefit from ECMO
support, and these patients would be best treated at experienced centers
with a multidisciplinary approach as illustrated by this clinical
case.7 Concerns related to exposure of healthcare
providers might be lower than expected. These patients present to the
ECMO team intubated with airway connected to a close ventilator circuit
and ECMO provides the clinical stability to facilitate their transfer.
Nonetheless, all personnel involved in mobile ECMO operations should
adhere to strict protocols related to use of PPE, and the vehicle and
devices used for the transfer of the patient should undergo terminal
decontamination.8 We believe high volume ECMO centers
should reconsider restrictive mobile ECMO policies. The establishment of
regionalized mobile ECMO centers would need to involve coordination
among area hospitals with regard to communication, reciprocity
considerations, and bioethics teams. Development of these regional hubs
of ECMO expertise with mobile capabilities could offer needed rescue
support to patients and provide ideal healthcare services to patients
within specific regions.
Figure 1: Multiple dimensions included in treatment of patient
with COVID-19 related ARDS.