One Disaster After Another or a Timely Help? The Role of ECMO for COVID-19 Patients

To the Editor: We would like to share our opinions regarding the concerns that extracorporeal membrane oxygenation (ECMO) may itself aggravate systemic inflammatory response in coronavirus disease 2019 (COVID-19) patients as raised by Dr. Angouras regarding our recently published clinical experience.1 Although the ECMO technology evolved from cardiopulmonary bypass (CPB) during cardiovascular surgery, research has demonstrated that the degree of systemic inflammatory response is quite different and much less compared with CPB because ECMO is a closed system.2,3 This is one of the main reasons that ECMO technology can be safely utilized in critically ill patients for a relatively long periods of support. At the same time, we must realize that ECMO technology does have a certain degree of inflammatory activation. Therefore, we should balance the advantages of ECMO for respiratory support and the possible risks of systemic inflammation aggravated by ECMO. In Shanghai, we were able to admit all patients diagnosed with COVID-19 into one designated hospital.1 We monitored major organ function and inflammatory response in all patients including mild, moderate, severe, and critically ill patients. We found that the severity and duration of systemic hypoxia may be the most important cause of systemic inflammatory response and organ dysfunction. Therefore, we implemented a strategy to prioritize treatment of systemic hypoxia. Under this principle, it is necessary to strictly follow the adult (or acute) respiratory distress syndrome treatment guidelines for critically ill patients, and reasonably use ECMO technology for respiratory support on the premise of sufficient medical resources. Traditional ECMO indications might lead to prolonged hypoxia and multiple organ failure in these patients. Therefore, we adopted early ECMO when mechanical ventilation was insufficient to correct hypoxia in COVID-19 patients. However, we observed that once the patients who met our indications were established on effective ECMO support with protective lung ventilation and completely reversed the systemic hypoxia state, the systemic inflammatory indexes actually decreased in varying degrees. We speculated that the benefits from the decrease in systemic hypoxia with ECMO outweighed the systemic inflammatory response induced by ECMO itself in COVID-19 patients. The Initial Extracorporeal Life Support Organization Guidance Document: ECMO for COVID-19 patients with severe cardiopulmonary failure emphasized that whether ECMO is applied to COVID-19 epidemic should be a local (hospital or regional) responsibility.4 "It is a case by case decision that should be reassessed regularly based on overall patient load, staffing, and other resource constraints, as well as local governmental, regulatory or hospital policies." In Shanghai, all COVID-19 patients were admitted to designated hospitals and financial support was provided. Shanghai made every effort to save every COVID-19 patient. Multidisciplinary critical care teams with extensive ECMO experience supported the designated COVID-19 hospitals. A total of 12 ECMO units were enlisted to care for the critically ill COVID-19 patients, with four units stationed outside the hospital as backup. It is only possible to implement successful ECMO management for COVID-19 patients with abundant resources and support. In summary, early and timely correction of systemic hypoxia via ECMO support might actually reduce the systemic inflammatory response in COVID-19 patients. Adequate medical resources and highly experienced ECMO teams are key to successful ECMO support in COVID-19.

Topic: Mechanical Circulatory Support Devices
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences