A brain oxygen level below 46% during CPR marks a physiological point of no return where resuscitation is no longer possible.
Medical teams currently struggle with the agonizing decision of when to stop trying to revive a heart attack victim. Measuring regional cerebral oxygen saturation provides a real time window into whether the brain is still viable. A prospective study found that no patient falling below this specific threshold ever regained a pulse or consciousness. This tool gives doctors the data they need to stop chest compressions with near certainty when there is no longer any hope.
Regional Cerebral Oxygen Saturation as an Adjunctive Tool for Termination-of-Resuscitation Decisions in Out-of-Hospital Cardiac Arrest: A Prospective Observational Study
SSRN · 6621594
Background: Widely accepted in-hospital termination-of-resuscitation (TOR) rules are currently lacking, and existing approaches do not incorporate real-time physiological monitoring. Regional cerebral oxygen saturation (rSO₂) has been associated with return of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR), but its role in TOR assessment remains unclear. Methods: In this prospective observational study, adult patients with out-of-hospital cardiac arrest who underwent r