Apnea Testing for Determination of Brain Death in Children Supported with Veno-arterial ECMO
Thomas A. Nakagawa1, Rima J. Jarrah2, Samuel J. Ajizian3, Swati Agarwal5, Scott C. Copus
1Anesthesiology, Wake Forest Baptist Health, Brenner Children's Hospital, Winston-Salem, NC, United States, 2Anesthesiology, Wake Forest Baptist Health, Brenner Children's Hospital, Winston-Salem, NC, United States, 3Anesthesiology, Wake Forest Baptist Health, Brenner Children's Hospital, Winston-Salem, NC, United States, 4Pediatrics, Section of Pediatric Critical Care, Inova Fairfax Hospital for Children, Falls Church, VA, United States, 5Respiratory Care, Wake Forest Baptist Health, Brenner Children's Hospital, Winston-Salem, NC, United States
INTRODUCTION. The updated United States guideline for the determination of brain death in infants and children provides important direction for clinicians tasked with determining death.[1] The guideline unfortuantely lacks direction for apnea testing when a patient is supported on extracorporeal membrane oxygenation (ECMO), as no published literature exists for this clinical situation.
METHODS. Retrospective observational case review.
RESULTS. Three children ages 5 months, 2 years, and 14 years, supported on veno-arterial (VA) ECMO following cardiopulmonary arrest, developed a neurologic exam consistent with brain death. Apnea testing on VA ECMO was successfully performed using the following method:
1. PaCO2 was normalized by adjusting ECMO sweep gas flow and obtaining a baseline arterial blood gas (ABG) analysis.
2. Sweep gas FiO2 was increased to 1.0 to provide preoxygenation on VA-ECMO.
3. A flow-inflating bag system with continuous positive airway pressure and FiO2 1.0 was used after removing the patient from mechanical ventilation support.
4. Sweep gas flow was reduced to 0.1 L/min for smaller children and 1.0 L/min for larger children while maintaining sweep gas FiO2 at 1.0. Rate of PaCO2 rise was monitored using CDI blood parameter monitoring system and correlated with ABG analysis to confirm PaCO2 level reached the recommended threshold to support brain death determination.
In two cases, apnea testing was able to be successfully performed. In one case, the patient developed hemodynamic instability and hypoxia, and the apnea test was terminated.
CONCLUSIONS. This pediatric case series describes a method of conducting apnea testing for children supported with VA ECMO. We address an important clinical scenario that has not been previously described in children undergoing brain death testing.