**Optimal Ventilation for Cardiac Arrest Study** Pediatric cardiac arrest is a very serious problem that happens to over 15,000 children in hospitals each year. Cardiac arrest means the heart stops beating suddenly. Less than half of these children get better and leave the hospital, and many who do have brain problems. This study wants to test the OPTI-VENT bundle, which is a group of treatments, to see if it helps more children survive with good brain health after cardiac arrest. The study looks at kids who have had at least 1 minute of CPR (Cardiopulmonary Resuscitation, which is when you push on the chest to help the heart pump blood). **Key Points:** - **Duration & Visits:** The study does not specify how long it lasts or how many visits are needed. - **Eligibility:** Kids must have a breathing tube (invasive airway) during CPR or within 5 minutes, and have had at least 1 minute of CPR. - **Exclusions:** Kids won't be in the study if the CPR was for end-of-life care, if they were determined brain dead before CPR, if they had a cardiac arrest outside the hospital, or if they were on Veno-Arterial ECMO (a special heart-lung machine) when CPR started. This study aims to help more kids survive with healthy brains after a cardiac arrest.