X-Message-Number: 1914 Date: Mon, 8 Mar 93 01:15:33 CST From: Brian Wowk <> Subject: CRYONICS Reply to Ettinger Robert Ettinger: > Even more basic is the question of estimating the bottom-line change > in the patient's chances. Knowledgeable people think the reduction in > cracking is *significant* near GT; but even if it is 95%, there will > still remain 5% cracking, which could well require full-fledged > nanotech for repair. If nanotech is (probably) both necessary and > sufficient for either procedure, then it becomes very hard to justify > the more expensive procedure, except for those rich enough to be > willing to pay a high premium for a marginal and possibly meaningless > improvement. This may be an academic point. Maybe I'm naive, but I am now coming to think that the robustness and easy scaling of foam-insulated vapor cooling vaults may quickly make this technology *cheaper* than LN2 storage in hard (or soft) vacuum dewars. Of course, there is also the question of reversible brain preservation. If such a technology comes on line within the next few years, cracking is no longer a marginal issue; it makes or breaks :-) the whole idea. > Similar remarks apply to the whole question of improvements in the > hypothermic phase (except as these relate to improvements in > cryoprotectant uptake). We know that several people have fully > recovered after drowning in cold water, even after being under water > for 45 minutes or more. In other words, with prompt topical cooling, > they made complete recovery with no prior medication or treatment of > any kind. This appears to prove that - within the limits of these > examples, including the fact that they were initially healthy people > and the cooling was only moderate -- any treatment prior to or > coincident with death can have only marginal importance. I believe this paragraph is misleading. It should not be interpreted to mean that people can easily survive 45 minutes of normothermic cardiac arrest. First of all, I suspect that these drowning victims' hearts continued to pump for a good portion of the 45 minutes they spent underwater. Blood has a surprisingly large oxygen carrying capacity; enough to keep things going for ten or more minutes with no respiration. This goes double for people subjected to rapid cooling. I also dispute that the cooling was "moderate." Cryonics patients subjected to SQUID cooling (a device that circulates ice water over the patient's body) drop down to 25'C in only 30 minutes. I would expect similarly dramatic cooling in cold water drowning. What this means is that unless a cryonics patient gets prompt cardiopulmony support and SQUID-style cooling, they are going to be in far worse shape after 45 minutes of cardiac arrest than a cold water drowning victim. Since not all cryonics organizations provide this level of support, this is an important point. --- Brian Wowk Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=1914