Hypoxic ischemic brain injury is a devastating illness that occurs after cardiac arrest (the heart stopping) and can yield irreversible brain damage, often leading to death. The mainstay in therapy is to optimize the delivery of oxygen to the brain to help it recover. In patients with traumatic brain injury (similar to HIBI), the investigators are able to optimize oxygen delivery to the brain with the use of wires placed into the brain that sense the pressure and oxygen in the skull to find the ideal blood pressure for each individual patient. This strategy is associated with improved outcomes. The investigators are conducting a prospective study investigating whether the perfusion within proximity to the optimal MAP is associated with improved brain oxygenation and blood flow .

Inclusion Criteria:

• Confirmed cardiac arrest with return of spontaneous circulation > 10 minutes
• post resuscitation GCS < 9

Exclusion Criteria:

• concurrent coagulopathy
• prior history of TBI, intracranial hemorrhage, subarachnoid hemorrhage
• anticipated cardiac catheterization within next 7 days
• anticipated or current use of anticoagulants or anit-platelets