If cells die after reintroduction to oxygen, that would mean the cells already reached the point of no return, since cells require oxygen to survive.
The objective would be to find a way to clear the enzymes out of the cell before you reintroduce the oxygen. Or perhaps you could give the medics a medicine that would shut down the production of the enzymes to make it easier to resuscitate when the patient gets to the hospital. As you can read in Wiki,
"permanent brain cell damage occurs when fresh blood infuses the cell". Up until the point they attempt to resuscitation, the cell is just fine. It would help if I could find where I put those photos.
"After more than 2 decades of clinical trials failed to demonstrate benefit from a host of putative neuroprotective strategies, two clinical trials that were published in 2002 showed that induced mild hypothermia can ameliorate brain injury, improving survival and functional neurologic outcome in comatose survivors of out-of-hospital cardiac arrest."
"CPR is likely to be effective only if commenced within 6 minutes after the blood flow stops
[78] because
permanent brain cell damage occurs when fresh blood infuses the cells after that time, since the cells of the brain become dormant in as little as 4–6 minutes in an oxygen deprived environment and, therefore, cannot survive the reintroduction of oxygen in a traditional resuscitation. Research using
cardioplegic blood infusion resulted in a 79.4% survival rate with cardiac arrest intervals of 72±43 minutes, traditional methods achieve a 15% survival rate in this scenario, by comparison. New research is currently needed to determine what role CPR, electroshock, and new advanced gradual resuscitation techniques will have with this new knowledge.
[79]
A notable exception is cardiac arrest that occurs in conjunction with exposure to very cold temperatures.
Hypothermia seems to protect by slowing down
metabolic and
physiologic processes, greatly decreasing the tissues' need for oxygen.
[80] There are cases where CPR, defibrillation, and advanced warming techniques have revived victims after substantial periods of hypothermia" wiki