When in trouble, double down: Double oxygenator ecmo support for refractory acidosis in Covid ARDS

ABSTRACT

INTRODUCTION: A patient on VV ECMO for COVID ARDS survived a prolonged ECMO course and refractory acidosis with double oxygenator support. METHODS: A 32-year-old previously healthy Latino male presented with cough, fever, myalgias and dyspnea and was positive for COVID-19. He was admitted on high flow oxygen but required mechanical ventilation on Hospital Day (HD)6. He developed oliguric renal failure and progressed to severe ARDS requiring paralytic, proning and PEEP of 16. He was cannulated for VV ECMO on HD9 for refractory acidosis and hypoxia. Murray score was >3, PF ratio was 60. Despite ECMO and continuous dialysis, the patient remained acidotic and was reliant on supplemental ventilator support, ongoing paralytic and heavy sedation. He developed a pneumothorax due to barotrauma and had multiple chest tubes for poor re-expansion. Due to maximum sweep support, an additional oxygenator was added on HD19. The patient had a prolonged recovery with complications of transfusion dependent epistaxis requiring ENT packing and hematochezia requiring rectal and IMA embolization. After significant transfusion he developed acute right ventricular dysfunction which was supported with inotropy and inhaled nitric oxide and later developed sepsis from bacteremia as well. He was finally stable for tracheostomy on HD61 and was decannulated from ECMO on HD66. He has since had cardiac and renal recovery and is weaning from vent support. RESULTS: ECMO has been used as rescue therapy in COVID ARDS but multi-center studies report mortality rates of 50% to as high as 94%- much higher when compared to MERS or H1NI viral ARDS support. Life threatening complications of bleeding, thrombosis, infection and refractory cardiopulmonary failure are common but COVID ARDS presents new physiologic challenges that are not yet well understood. As of July 27 2020, of a cohort of 148 ECMO supported COVID patients in the SpecialtyCare national perfusion database, the average support duration is 16 days (SD 14 days). Our patient required 57 days on ECMO and is the only patient to have survived double oxygenator support in our database. His case supports future use of additional oxygenators in refractory acidosis, which may be more common in COVID physiology. He also reminds us that prolonged COVID ARDS recovery is possible.