The World Health Organization interim guidelines recommend offering extracorporeal membrane oxygenation (ECMO) to eligible patients with acute respiratory distress syndrome (ARDS) related to coronavirus disease 2019 (COVID-19) (1). Obesity increases the risk of severe illness from COVID-19 (2). ECMO may still be used in the obese, although appropriate body mass index (BMI) cutoffs for beneficial intervention are unknown and several challenges remain (3,4). Most literature suggests that, in general, obesity may not be a determinant of poor outcome for venovenous ECMO (5,6). However, the use of a precious resource in the setting of the pandemic surge is somewhat controversial.
We describe a case of ARDS secondary to COVID-19 infection complicated by a possible acute coronary syndrome (ACS) in the setting of super morbid obesity (BMI 73.9 kg/m2) where we used venovenous ECMO and a collaboration of multidisciplinary critical care and ancillary services to achieve a complete recovery for this 18-year-old patient. This remains the heaviest reported survivor of COVID-19 on venovenous ECMO to date.
HIPAA authorization was obtained from patient’s mother for writing this article.
An 18-year-old patient weighing 512 lbs (BMI 73.9 kg/m2) was admitted to the medical ICU (MICU), where he presented after 3 days of worsening dyspnea and chest pain. The clinical picture was also complicated by possible ACS with an initial troponin of 0.294 ng/mL (normal < 0.025 ng/mL), which peaked to 66.450 ng/mL 18 hours later (other pertinent laboratory tests in Table S1, https://links.lww.com/CCX/A496). Chest radiograph showed multifocal opacities throughout the lungs. Electrocardiography showed evidence of ST elevations in inferior leads with ST depressions in a video laryngoscope (VL) as well as V2 (Fig. S1, https://links.lww.com/CCX/A496). Transthoracic echocardiogram was unremarkable with a calculated ejection fraction of 40%. Given the patient’s body habitus, cardiac catheterization was deferred. Tissue plasminogen activator was administered for diagnosis of ST-segment elevation myocardial infarction. Nasopharyngeal swab for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) later returned positive on a real-time reverse transcriptase–polymerase chain reaction assay. While in the MICU, he developed increasing tachypnea and a decision was made to intubate him for clinically increased work of breathing and mixed hypoxic hypercapnic respiratory failure.
We reviewed departmental guidelines and followed established expert opinion for safe airway management of patients with SARS-CoV-2 infection (7). To minimize exposure, only an anesthesiologist, ICU nurse, and respiratory therapist entered the patient’s room. Despite patient position optimization and a grade 1 Cormack-Lehane view with a hyperangulated VL blade, intubation was not successful on the first attempt, necessitating the insertion of a Bougie Coudé tip endotracheal tube (ETT) introducer via VL followed by ETT insertion.
Post intubation, he continued to have persistent hypoxemia despite optimization of ventilator settings on sedation and paralysis. He was deemed not to be suitable for prone positioning due to his large body habitus. Our ECMO team was hence consulted. After careful consideration of risk versus benefit and a discussion of the same with his mother, the patient was transferred to our cardiovascular ICU and cannulated via right internal jugular vein using a 32F crescent venovenous double-lumen bicaval ECMO cannula under fluoroscopic guidance (Fig. 1A).
Post cannulation, he continued to have refractory hypoxemia, which was largely due to an intrinsic total cardiac output (CO) of up to 20 L/min (LPM) and a large shunt fraction bypassing the ECMO circuit. He was started on deep sedation and continuous IV esmolol drip with an improvement in hypoxia concomitant with a drop in heart rate and CO. In addition, he received mesenchymal stem cell therapy as part of an ongoing institutional trial (under Institutional Review Board approval), broad-spectrum antibiotics, and anticoagulation with heparin using standard ECMO protocols. With ongoing clinical and radiological improvement, the ECMO circuit was capped on day 20. After approximately 30 hours without support, he was then decannulated on day 21 (Fig. 1B). Throughout the patient’s course, specific inflammatory markers trend correlated well with the degree of illness as shown in Figure 2.
Shortly after decannulation, he developed hypoxemia and hypotension along with high-grade fever. This required aggressive resuscitation including reinitiation of vasopressors and an addition of angiotensin II. Blood and sputum cultures grew methicillin-sensitive Staphylococcus aureus (MSSA) at that time, for which patient received IV cefazolin. Serum renin obtained at this time was 41 ng/ml/hr (normal range with sodium replete: ≤ 0.6–4.3 ng/mL/hr). There was a good response to exogenous angiotensin II along with other therapeutic interventions, and he had stable vitals before transfer back to MICU for further management, including ventilator weaning.
During MICU stay, the course of illness was complicated by high positive end-expiratory pressure requirements (16–24 cm of support), recurrent ventilator-associated pneumonia, repeated failure to wean from the ventilator, marked delirium, and critical illness myopathy. With persistent ventilator dependence and the need for aggressive pulmonary toilet, acute care surgery team placed a surgical tracheostomy successfully on day 57. A pertinent timeline of events during his clinical course are depicted in Figure 3. After being gradually weaned to tracheostomy collar trials, he was subsequently transferred to the general care floor under the care of the hospital medicine service. He was ultimately discharged home with a capped tracheostomy tube after 96 days of hospital care and is currently being followed closely as an outpatient with subspecialty clinics. Supplementary Appendix (https://links.lww.com/CCX/A496) contains additional details of the clinical perspective of this patient’s care and current clinical status, who to the best of our knowledge is back to baseline functionality.
Although a common factor with COVID-19 patients and poor outcomes, obesity is not associated with worse outcomes for patients requiring venovenous ECMO in general (8,9). However, no identified cutoff value is established for a safe BMI for effective clinical use of an extracorporeal oxygenation circuit. In their analysis of the Extracorporeal Life Support Organization (ELSO) database, Al-Soufi et al (9) found that increased body weight was not a risk factor for hospital mortality in patients requiring venovenous ECMO. Similarly, Galvagno et al (5) did not show an association of obesity with mortality in a retrospective analysis of 194 ECMO patients with a median BMI of 35 kg/m2.
Selection of COVID-19 patients with respiratory failure and allocation of ECMO resources is also a matter of local institutional supply-demand balance and adherence to established guidelines set forth by ELSO and the Centers for Disease Control and Prevention (10,11). Our decision to offer venovenous ECMO for our patient stemmed from a combination of adequacy of underlying cardiac function (good LV function with high CO as confirmed by formal echocardiography and device-based measurements), no other irreversible organ system failure, less than 24 hours on mechanical ventilation, and the age of this patient. In addition, our calculated respiratory ECMO survival prediction score showed upwards of 75% survivability (12).
One challenge is that obese patients can have higher CO than nonobese patients (13). With most ECMO circuits having a maximum flow of around 6 LPM, this will often not match CO of the patient and leads to ongoing hypoxia due to a large shunt fraction bypassing the ECMO circuit. Use of two oxygenators in parallel in circuits under these circumstances, an extra drainage cannula, or even use of two separate circuits to match the tremendous needs of the obese patient have all been described (14). Our patient’s habitus made additional access a challenging prospect, and it was not felt that an additional oxygenator would provide significant benefit with a flow of 6 LPM. We used gradual reduction of CO for the treatment of refractory hypoxemia as found helpful in patients with high-flow ECMO and high endogenous CO using ultra-short-acting β-blockers (15).
COVID-19 patients are at risk for superimposed septic shock with secondary infections. Our patient developed MSSA septicemia that required aggressive resuscitation, along with the use of angiotensin II as a vasopressor when he reached a stage of high dose catecholamine nonresponsiveness. Serum renin was high, and this retrospectively justified the use of exogenous angiotensin II rescue along with the immediate response to the agent. In addition, his inflammatory markers peaked 24 hours later, likely secondary to septic shock or a manifestation of the COVID-associated inflammatory cascade. Interestingly, an overall look at inflammatory marker profile for this patient showed a brief period of elevation during the initial course of illness, and hence his highest inflammatory state did not coincide with the most marked respiratory failure, rather the period of superimposed septic shock. Also, our patient was first admitted in April 2020 when there was minimal, if any data on the utility of steroids or remdesivir, thus negating any thoughts of the use of these drugs.
As of December 5, 2020, 3,547 confirmed COVID-19 patients had used ECMO in the ELSO registry. Of these, 1,288 (49%) had obesity reported with a median BMI of 32 kg/m2 (10). With some careful consideration, we used this valuable resource to good effect and had a 512 lbs COVID-19 survivor on venovenous ECMO who spent 96 days in the hospital and is the heaviest reported such patient in the history of the pandemic so far. The value of a collaborative multidisciplinary effort to achieve a successful outcome for this super morbidly obese patient with COVID-19 pneumonia cannot be understated.
We appreciate every healthcare personnel involved in this patient’s care at Wake Forest Baptist University Hospital, Winston-Salem, North Carolina.
1. Ramanathan K, Antognini D, Combes A, et al. Planning and provision of ECMO services for severe ARDS during the COVID-19 pandemic and other outbreaks of emerging infectious diseases. Lancet Respir Med. 2020; 8:518–526
2. Simonnet A, Chetboun M, Poissy J, et al.; LICORN and the Lille COVID-19 and Obesity study group. High prevalence of obesity in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) requiring invasive mechanical ventilation. Obesity (Silver Spring). 2020; 28:1195–1199
3. Osho AA, Moonsamy P, Hibbert KA, et al. Veno-venous extracorporeal membrane oxygenation for respiratory failure in COVID-19 patients: Early experience from a major academic medical center in North America. Ann Surg. 2020; 272:e75–e78
4. Barbaro RP, MacLaren G, Boonstra PS, et al.; Extracorporeal Life Support Organization. Extracorporeal membrane oxygenation support in COVID-19: An international cohort study of the Extracorporeal Life Support Organization registry. Lancet. 2020; 396:1071–1078
5. Galvagno SM Jr, Pelekhaty S, Cornachione CR, et al. Does weight matter? Outcomes in adult patients on venovenous extracorporeal membrane oxygenation when stratified by obesity class. Anesth Analg. 2020; 131:754–761
6. Kon ZN, Dahi S, Evans CF, et al. Class III obesity is not a contraindication to venovenous extracorporeal membrane oxygenation support. Ann Thorac Surg. 2015; 100:1855–1860
7. Cook TM, El-Boghdadly K, McGuire B, et al. Consensus guidelines for managing the airway in patients with COVID-19: Guidelines from the Difficult Airway Society, the Association of Anaesthetists the Intensive Care Society, the Faculty of Intensive Care Medicine and the Royal College of Anaesthetists. Anaesthesia. 2020; 75:785–799
8. Ni YN, Luo J, Yu H, et al. Can body mass index predict clinical outcomes for patients with acute lung injury/acute respiratory distress syndrome? A meta-analysis. Crit Care. 2017; 21:36
9. Al-Soufi S, Buscher H, Nguyen ND, et al. Lack of association between body weight and mortality in patients on veno-venous extracorporeal membrane oxygenation. Intensive Care Med. 2013; 39:1995–2002
10. Extracorporeal Life Support Organization. Full COVID Registry Dashboard. Available at: https://www.elso.org/Registry/FullCOVID19RegistryDashboard.aspx
11. Centers for Disease Control and Prevention. Guidance for U.S. Healthcare Facilities About Coronavirus (COVID-19). Available at: https://www.cdc.gov/coronavirus/2019-ncov/hcp/us-healthcare-facilities.html
12. Schmidt M, Bailey M, Sheldrake J, et al. Predicting survival after extracorporeal membrane oxygenation for severe acute respiratory failure. The Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) score. Am J Respir Crit Care Med. 2014; 189:1374–1382
13. Vasan RS. Cardiac function and obesity. Heart. 2003; 89:1127–1129
14. Umei N, Ichiba S. Venovenous extracorporeal membrane oxygenation as a treatment for obesity hypoventilation syndrome. Case Rep Crit Care. 2017; 2017:9437452
15. Guarracino F, Zangrillo A, Ruggeri L, et al. β-Blockers to optimize peripheral oxygenation during extracorporeal membrane oxygenation: A case series. J Cardiothorac Vasc Anesth. 2012; 26:58–63