BRAIN DEATH DETERMINATION ON VENO-ARTERIAL EXTRACORPOREAL MEMBRANE OXYGENATOR (VA-ECMO)

Abstract

SESSION TITLE: Clinical Conundrums in ECMO SESSION TYPE: Fellow Case Reports PRESENTED ON: 10/20/2019 01:00 pm - 02:00 pm INTRODUCTION: The use of Extracorporeal Membrane Oxygenation (ECMO) has increased dramatically in the last decade. One challenge that physicians face is performing apnea test in patients on ECMO for brain death certification. There is no consensus on how to proceed with apnea test on ECMO. The aim of this case report is to add to the literature and contribute to the future development of guidelines. CASE PRESENTATION: A 58-year-old male presented with a non-ST elevation myocardial infarction. Coronary angiogram showed multi-vessel disease and he underwent a coronary artery bypass graft surgery. His course was complicated with acute graft thrombosis, requiring re-sternotomy, exploration and mechanical support with Veno-Arterial ECMO. In the following days, he lost corneal, gag, oculocephalic and oculovestibular reflexes. Pupils were fixed and dilated. He was not responsive to pain. According to Florida statute, apnea test was indicated for the determination of brain death. He was pre-oxygenated with fraction of inspired oxygen (FiO2 - ventilator) and fraction of delivered oxygen (FDO2 - ECMO) of 1.0. After 10 minutes an arterial blood gas (ABG) showed a pH 7.33, pO2 109, pCO2 37. Sweep flow was decreased to 0.5L and the FiO2 and FDO2 left at 1.0. Patient was disconnected from the ventilator and no spontaneous breaths were noted; repeat ABG revealed pH 7.22, pO2 106, pCO2 58. The apnea test was positive. Bedside electroencephalogram was supportive of brain death and patient was declared brain dead. DISCUSSION: Brain death is a devastating and irreversible neuronal injury that is expressed with coma and absence of brainstem reflexes. Our patient was on VA ECMO due to cardiogenic failure from graft thrombosis. Due to the patient’s post-operative course, it was very likely that he had sustained significant neurologic damage. There is no standardized way to perform apnea test while on ECMO. We made modifications in order to minimize the removal of carbon dioxide (CO2) with the ECMO membrane as much as possible while adequately oxygenating the patient. There is a handful of case reports that showed that it was possible to perform this test with some modifications. Patients should be adequately pre-oxygenated and we should confirm eucapnia. The sweep flow should be decreased to 0.5 to 1L/min and FiO2 and FDO2 increased to 1.0. The patient should then be disconnected from the ventilator and monitored for spontaneous breaths; ABG should be checked after 8–10 minutes. CONCLUSIONS: Brain death certification, while on ECMO, is becoming a more frequent clinical scenario as the use of extracorporeal life support continues to spread in intensive care units around the world. Our case validates the safety and feasibility of performing a reliable apnea test as part of the brain death certification process of patients on ECMO. We hope to contribute to the body of literature for the establishment of future guidelines. Reference #1: Muralidharan R, Mateen FJ, Shinohara RT, Schears GJ, Wijdicks EF (2011) The challenges with brain death determination in adult patients on extracorporeal membrane oxygenation. Neurocrit Care 14(3): 423- 426. Reference #2: S. Goswami, A. Evans, B. Das et al. Determination of brain death by apnea test adapted to extracorporeal cardiopulmonary rescuscitation. Journal of Cardiothoracic and Vascular Anesthesia, Vol 27, No 2 (April), 2013: pp 312-314 Reference #3: S. Hoskote, J. Fugate, E. Wijdicks. Performance of an apnea test for brain death determination in a patient receiving venoarterial extracorporeal membrane oxygenation. Journal of Cardiothoracic and Vascular Anesthesia. 2014, August; 28(4):1027-1029. DISCLOSURES: No relevant relationships by Mauricio Danckers, source=Web Response No relevant relationships by Jasdip Grewal, source=Web Response no disclosure on file for Jose Ramirez; No relevant relationships by Alwiya Saleh, source=Web Response No relevant relationships by Jonathan Urbina, source=Web Response