Inclusion Criteria:  In-hospital cardiac arrest patient Age ≥18 years Age <80 years CPR lasting ≥5 minutes  Exclusion Criteria:  Patients < 18 years of age or > 80 years of age Out of hospital cardiac arrest patients ≥3 acute organ failures (defined as acute renal failure requiring dialysis, fulminant liver failure i.e. liver failure with INR≥1.5, respiratory failure requiring mechanical ventilation) Repeat in-hospital cardiac arrest event within 14 days of a prior cardiac arrest Presence of known raised intracranial pressure Presence of known traumatic brain injury or subarachnoid hemorrhage <14 days old, frontal lobe brain tumors or subdural hemorrhage Hyperbilirubinemia >1.0 mg/dl (based on the absorption of near-infrared light by bilirubin) Resuscitation using extra-corporeal membrane oxygenation (ECMO)