Hydrogen's Feasibility and Safety as a Therapy in ECPR

INCLUSION CRITERIA In order to be eligible to participate in this study, an individual must meet all of the following criteria: 1. Patients admitted to a cardiac intensive care unit at a participating site with cardiac comorbidity, including congenital heart disease, myocarditis, cardiac arrhythmia, or rejection of a transplanted heart. 2. Patients are anticipated to be between birth to 18 years of age, although occasionally a patient over the age of 18 may be enrolled. 3. Patient experiencing a refractory cardiac arrest \>5 minutes and receiving ongoing CPR in the ICU, cardiac catheterization lab, or cardiac operating room. 4. The decision made by the clinical team to resuscitate from ongoing, refractory cardiac arrest using ECPR due to a lack of other available options. EXCLUSION CRITERIA Meeting any of the following criterion renders the patient ineligible for the trial: 1. Enrollment in the opt-out program. 2. Patients known to be pregnant. 3. Patients who are prisoners. 4. Prior ECPR episode during admission (whether or not they were enrolled in the trial). 5. Enrollment does not occur within 6 hours of the decision to resuscitate using ECPR. Note that ECMO cannulation without preceding CPR does not qualify as ECPR and such patients will not be included.