X-Message-Number: 8314 From: () Newsgroups: sci.cryonics Subject: Re: review of suspended animation prospects Date: 9 Jun 97 21:30:37 GMT Message-ID: <> References: <> In <> (Joseph J. Strout) writes: >Suspensions of up to an hour are fairly routine (from the article, which I >have now read), and their goal is to extend this to three hours or so. And >of course this is no substitute for cryonics, but that wasn't my purpose in >pointing it out. Rather, we should take careful note of the procedures >used to get patients successfully down to deep hypothermia (around 5 C), >and hold them there stably. The very same procedures may be useful in >cryonic suspensions to (a) get the patient's temperature down while >preventing ischemic damage, without chemical toxicity, and (b) pause there >as needed for evaluation, preparation, or transport, before the final >freezing phase. During the mid 1980's, Jerry Leaf and Mike Darwin at Alcor set several records for deep hypothermia recovery (which sadly were never published in refereed journals). Their work culminated in the recovery of dogs after 4 hours of bloodless perfusion at 4'C. This record was subsequently extended at 21st Century Medicine to about 5 hours. The motive of this work was exactly what you suggest: Improving the reversibility of the early stages of human cryopreservation. It should be mentioned that there are two different models of hypothermia: circ arrest and bloodless perfusion. The perfusion model allows you to get out to 5 hours near freezing, while circ arrest is still limited to about 2 hours. The perfusion model is pertinent to what happens to cryonics patients during stabilization and cryoprotective perfusion. The circ arrest model is pertinent to cryonics patients being shipped on ice without CPR. >Moreover, to the extent that we are using such procedures already (and I >really have no idea who is and is not), we can state with assurance that >the cryonics patients are viable up to that point at least -- or would be, >if not for whatever killed them in the first place. You can drop the "if not for whatever killed them" part. In the first case Biopreservation did for CryoCare (Jim Gallagher) there was no question that the patient was viable (and likely recoverable) by present criteria for almost two hours after legal death. The blood gases and enzymes tell the tale. It's unlikely that any other organizations are equalling this performance since only BioPreservation uses ACDC CPR and a constellation of new drugs to inhibit ischemic injury. Cryonics patients differ from animal studies in that cryonics patients do not come prepped with heart-lung machine support before cardiac arrest occurs. So how you reestablish blood circulation, cool the patient, and medicate them are crucial to success. *************************************************************************** Brian Wowk CryoCare Foundation 1-800-TOP-CARE President Human Cryopreservation Services http://www.cryocare.org/cryocare/ --------------------------------------------------------------------------- Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=8314