One strong, although not absolute common thread in these resurrection stories is cold temperatures.
All the various medical groups hot on the trail of cryotherapy, induced hypothermia etc. are definitely onto something. IIRC, Russia/Former USSR did a lot with open heart surgery without needing bypass machines using forced cooling of the patient.
AJ, we actually induce hypothermia in patients post cardiac arrest. It is shown to significantly reduce their deficits on discharge (that is, presuming they don't code again).
Also, cold water drownings are a big source of these types of cases as well. Our rule is, they aren't dead until they're *warm* and dead. And since we don't do active rewarming in the field, we let the hospital determine what warm and dead is.
The caveat is that the water has to be *COLD*. Less than 40 degrees F. I'm actually looking at some notes I took on this earlier this year.... The longest recorded survival for a cold water drowning is 66 minutes, the longest drowning with absolutely no neurological deficits was 41 minutes (kid fell through ice). That is time submerged in the water!
The theory behind it is that mild hypothermia is believed to be a neuroprotective mechanism. It slows down the metabolism so stores of glucose and oxygen are not consumed as quickly.
The same general principle applies to induced hypothermia post resuscitation.