Neuroprognostication Using Optic Nerve Sheath Diameter

Inclusion Criteria: * Patient ≥ 18 years of age * Patient has experienced either an in-hospital or out-of-hospital cardiopulmonary arrest * Patient is comatose or exhibits lack of meaningful response to verbal commands with return of spontaneous circulation (ROSC) after cardiopulmonary arrest * Patient must meet all inclusion criteria as deemed by physician and the 2015 American Heart Association standards for targeted temperature management (TTM) following cardiopulmonary arrest Exclusion Criteria: * Patient \< 18 years of age * Patient does not meet inclusion criteria for targeted temperature management (TTM) * Unable to obtain consent from Legal Authorized Representative (LAR) * Patient has a Do Not Resuscitate (DNR) order or a Do Not Intubate (DNI) order at the time of consent * Patient has uncontrollable bleeding * Patient is able to follow verbal commands * Patient has another medical condition creating increased ocular pressure, as deemed by physician