I freeze people's brains for a living.
J Thoendell stashed this in Science
So we’ve got a living brain and person who’s pronounced dead, so we try to slow down the metabolism in the brain so that those cells won’t die. We are trying to preserve all the intricate branches, about 2000, on each neuron, as well as the specific shapes of each synapse. If we cool them, it lengthens the amount of time before they actually die. So we try to keep them alive as long as we possibly can. We put the person in an ice-bath—it’s kind of like a stretcher with walls on it that contains ice water. That’s the fastest we can cool externally. We start cooling, we start moving them out of the facility, we try to give medications that will stop the blood from clotting and will help slow down the metabolism further. An important one would be an antibiotic: we don’t want bacteria to grow while we’re doing this. Another important one would be Heparin to prevent blood clotting; we could also use Citrate depending on the situation. Another medication we can use would be Vasopressin—we want to constrict the blood vessels on the extremities to concentrate the blood flow to the core. We can use some of vasopressors—they use those in emergency medicine too, and might have them in an ambulance.
We try to compress the heart with chest compressions, either via CPR or with a machine, to try to circulate the blood a little bit. The purpose of circulating the blood is to get the medications where they need to be and to also help with cooling.
If somebody’s been pronounced dead and then you start CPR, you don’t want the embarrassing situation where they start to wake up again. For older people that are really far gone it’s not a concern, but sometimes life can start to come back a bit so general anesthetic takes care of that. It happened early in Cryonics, not so much anymore because we do use medications like Pentobarbitol and Propofol, which is what Michael Jackson died from. These are general anesthetics. They slow down the metabolism and reduce consciousness.