The Effect and Safety of Hydrogen Inhalation on Outcome Following Brain Ischemia During Post Cardiac Arrest Care: HYBRID study (Pilot study) - The Effect and Safety of H2 inhalation for patient with post cardiac arrest syndrome

We consecutively enrolled 5 patients between January 1, 2014, and January 19, 2015. Three of the patients (60%) were male, and the average age was 65+-15 years. Collapse was witnessed for all patients; 4 patients (80%) had received bystander-performed cardiopulmonary resuscitation, 4 patients (80%) were initially in ventricular fibrillation, and 4 patients (80%) had a cardiac etiology. The time interval from collapse until return of spontaneous circulation (ROSC) was 16+-4.7 min, and the time from ROSC until the initiation of HI was 4.9+-1.2 h. All patients were successfully treated with TTM between 33 and 36 degree Celsius. Hydrogen gas inhalation (HI; 2% H2 with oxygen) was initiated through a ventilator upon ICU admission and was continued for 18 h. HI was successfully applied to all the eligible patients as scheduled. The Data and Safety Monitoring Committee reviewed all adverse events (AEs) and examined their causal relationships with events and HI, concluding that no AEs were causally related to HI. The neurological intact survival rates (ie, patients with cerebral performance category (CPC) of 1,2) were assessed at 90 days after CA. An outcome of CPC 1 had been achieved by 4 of the 5 patients. One CA patient with severe pneumonia and septic shock died of respiratory deterioration 22 h after the discontinuation of HI.