To Evaluate the Feasibility and Safety of Selective Cerebral Hypothermia in Out-of-hospital Cardiac Arrest (OHCA) Patients Receiving ECPR.

Patients with OHCA and meeting the criteria for initiating extracorporeal membrane oxygenation (ECMO) criteria will be checked for eligibility for the study during CPR by the emergency physicians or staff at the scene. Informed consent will be asked as well. The standard V-A circuit for ECMO will be applied to the patients as soon as they arriving ER following the standard operation procedure of the hospital. The necessary testing and procedures will be applied to check the eligibility of the patients. Eligible subjects and/or their legal representatives will be further confirmed for the consent of experimental selective cerebral hypothermia. Systemic hypothermia at 33.5+/-0.5°C (33-34°C) for 48 hours will be performed to all eligible subjects.

For subjects who consent to receive selective cerebral hypothermia, they will be transferred to the catheterization lab for the blood flow controlling and cooling system settlement. Subjects then will be transferred to ICU for the 12-hour selective cerebral hypothermia procedure. Cooling will be initiated and targeted to reach ipsilateral nasal temperature of 27+/-2°C for 12 hours, followed by controlled rewarming. Both ipsilateral and contralateral nasal temperature will be monitored throughout. Activated clotting time (ACT) monitoring should be performed every 2 hours till stable and then every 12 hours during the whole cooling procedure. Also, subjects will receive systemic hypothermia via ECMO at 33.5+/-0.5°C (33-34°C) for 48 hours at the same time.

Subjects will stay and be observed in ICU until subject's condition is stable and can be transferred to general ward by investigator's judgment. The weaning of ECMO will be judged by investigator based on the subject's condition.

For subjects who do not agree to receive selective cerebral hypothermia, only the systemic hypothermia via ECMO will be applied. Subjects will receive systemic hypothermia at 33.5+/-0.5°C (33-34°C) for 48 hours via ECMO following the standard operative procedure.

Subject weaned from ECMO will be transferred to ward and will be followed until 6 months after the event. Outcome improvement and safety will be evaluated following scheduled timeline.