How soon will we be able to cryonically suspend and reanimate people clinically and safely?
There are a few people being cryonically suspended already, however current methods cause substantial damage to many organs including the brain. Thus it is reserved for patients who are already clinically dead, which is itself a traumatic and unpredictable process that tends to inflict additional damage.
However at the opposite end of the spectrum is the theoretical ideal of cryopreserving patients without any damage -- as is usually portrayed in science fiction -- which means a person can be reanimated without requiring extreme repairs.
That is a harder goal than current-day cryonics, of course. And yet, once the goal is achieved, it could be practiced routinely on living patients without harming them -- it would instead add many years to their lives. A technology such as this could transport sick people forward through time until whatever treatments they are waiting for have made it through clinical trials.
People with viral infections could go into stasis while awaiting the production of vaccines, for example. Even cures for very long term and highly complex conditions like the diseases and causes of aging are most likely possible if you can buy enough decades of time to test and develop them.
Is this a realistic possibility for humans currently living? Is there likely to be a safe, clinically reversible cryonics technology within our lifetimes?
Answer updated based upon reinterpretation of intent of anon OP.
The intent of the OP is whether or not cryonics will become a viable alternative in the field of emergency rescue. There are significant ethical and financial problems with indefinite cryopreservation that I will address after the use case of temporary or time-bound cryopreservation.
First, this assumes that cryopreservation is not being undertaken by otherwise healthy people. Even if there was reliable animal experiments which proved that a whole animal could be revived after cryogenic freezing with no apparent defects (which is not a technology I expect to see in the next 100 years), there would have to be a first patient, and as far as i know, you can't just sign your life away in exchange to be that first human subject.
The original question suggests that there is some technique that could slow metabolic rates on a whole body in order to preserve it for a time. There are two example use cases given- that the body is preserved until a cure can go through clinical trials (presumably the original intent of http://en.wikipedia.org/wiki/Dick_Clair ) or that the body is preserved until an organ transplant is available. I am going to suggest a simpler use case- in the event of an emergency evacuation due to trauma, so that the person can be transported (still alive) but with the body's mechanisms put on pause, so that a surgeon can be made available to provide the correct treatment. Let's call this the CryoAmbulance scenario.
But first, let me critique organ transplant. The article from the journal "Transplantation" (http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&term=%22Transplantation%22%5Bjour%5D) which documents a recent change in protocol from performing a randomized lottery for organ transplant versus transplanting those rated to die "soon" on a priority basis http://www.ncbi.nlm.nih.gov/pubmed/22531492 seem to bode poorly for survival rates from the priority group. This highlights a point I would like to make about transplants and surgery in general: the more dramatic a rescue, the more likely the higher cost (human and financial) of the procedure. This is not to say that given an infinite amount of resources, so called "post-scarcity", that everyone shouldn't be given the chance at life. I don't believe that you can put a price on life, and I am not arguing for terminating the poor. However, we don't have infinite money nor an adequate source of donor organs nor exactly the technology we need today to meet all unmet medical needs. The allocation of scarce resources, no matter how it is done, is not done scientifically. Rather, it is done with satisficing, trial and error at the cost of patients lives, and I don't feel that people take a good hard look at what they give to future society when they insist on revival at any cost without ability to pay. When ethically sourced transplant operations might cost up to $800k (http://en.wikipedia.org/wiki/Organ_transplantation) the debt you incur from said surgery goes somewhere, and people cease to think rationally.
The better approach will be for organ transplant based upon organs that are manufactured on demand. We are able to currently construct scaffolding for some autologous organ regeneration, but the technology is not quite there yet. I expect that the ability to regrow human organs will be advanced sufficiently to replace a major organ (heart, liver, lungs, amputation) within the next 50-60 years. There's a problem, though, with the brain and the immune system, which I like to call the "Theseus' ship" problem. http://www.productiveflourishing.com/the-ship-of-theseus-and-personal-identity/
The brain is often thought of as a blank slate, a kind of "neural network" which is simulated by computational neural networks. Disregarding the possibility that the analogy is incorrect (at which point I might just believe in an incorporeal soul), we make our decisions based upon however our experiences have molded themselves inside our head. Frequently, we would make different decisions "knowing what we know know" but disregard that having done it that way gave us the experience to believe that. I have argued elsewhere that non-invasive or non-destructive techniques will never have the image resolution to take a living person and snapshot them in time to make a backup Radiology: Will MRI technology ever reach the resolution to image individual neurons?. Because it is a limitation at a quantum level to create a sufficient copy at great enough detail through any possible frequency transmission bandwidth less that that of cosmic high-energy radiation beams, I don't believe brain transplants, in the sense of giving you a new brain engineered from your own dna and put back into your otherwise healthy body (head trauma use case) will ever be viable without serious loss of memory and experience. These limits will also take place for more localized surgeries- it becomes increasingly difficult to accurately "stitch" a repair the more extensive the stitch needs to be. It may be possible to parallelize this in future remote surgical techniques in the next 20 years. Problem is, if one doctor botches things, how do you find out who to sue?
The single question, though, that advocates of cryonics should consider, is whether or not they believe that a computer is an adequate model for the brain. If so, are they not concerned that as soon as the power is off, the memory and any semblance of what makes you "you" will be wiped? You might be convinced that neurons, because the axon fibers can grow and reconnect, is something like flash memory. However, isn't it more likely that those are reserved for biological instincts, like breathing and "flight or fight" and the general OS of muscle movement, with the higher order functions of memory and philosophy is more like reflection? http://en.wikipedia.org/wiki/Reflection_(computer_programming)
CryoAmbulance use case
(coincidentally to writing this response, Cracked does a great post on the subject of the real cost of ambulances: http://www.cracked.com/article_19798_5-terrifying-secrets-about-riding-in-ambulance.html?utm_source=facebook&utm_medium=fanpage&utm_campaign=new+article&wa_ibsrc=fanpage When you think of the ways people abuse ambulance care today, imagine the cost of cryoambulances, relative to my argument that people don't think rationally about cost when faced with infinite penalties such as death. Even if it is hallucinatory.)
In order to determine the technology to take a living patient and transport them effectively from where they happen to be to where they can get the best care, we have to understand what is state of the art technology.
If we are strictly talking about reducing body temperature to slow metabolic rate, we are talking about some form of hypothermia http://en.wikipedia.org/wiki/Hypothermia and it depends on what part of the body. The damage from hypothermia can be different depending on the particular organ, and on the body's ability to repair itself. With individual organs or severed limbs, the state of the art is about 12-24 hours, and tissues can be biobanked for up to five years. But the surgery for trauma is life altering, and the changes in a person's personality due to recovery from extreme hypothermia cannot be underestimated. When you elect for a procedure, you risk not only the ongoing pain from imperfect or needed excision, but the fact that cell death produces toxic materials and can make you much more susceptible to infection. Once infection sets in, it is extremely difficult to reverse.
Whole body hypothermia is typically restricted to about an hour without some alteration in the innate metabolism of the cells. As such, I don't forsee hypothermic or cryogenic preservation to ever be viable solely in terms of some combination of mechanical and thermal methods.
In essence, I would like to distinguish cryopreservation (icing or freezing to stop metabolism without some other change) with hibernation. Specific cases where this has been achieved do not necessarily require hypothermia- http://en.wikipedia.org/wiki/Induced_coma comes to mind. Hibernation http://en.wikipedia.org/wiki/Hibernation either by lowering metabolism with a drug in combination with mild hypothermia or by supplementing fluids with antifreezes to replicate the long-time freezing and revival of e.g. goldfish raises severe questions: to take a computer analogy too far, how much of the brain contents is "hardware", and how much "software"? The brain is in constant activity, and we don't know to what extent completely freezing out the electrochemical activity causes irreversible wiping of memory or knowledge. A goldfish doesn't have to keep a lot of memories to survive- just a set of basic survival instincts which might be pre-patterned in. Before undertaking such a procedure, you might have to sign a waiver that says not all of you might be still there when you wake up after the cryoambulance ride. If you happen to remember nothing of your life prior to the incident, philosophically speaking, why spend the extra money on preserving "you" as opposed to, say, growing an entirely new clone or just letting a newborn child take your place in carbon consumption.
I am not optimistic for many of the expected outcomes of emergency preservation. One can think of technologies like, for example, Star-Trek like stasis fields, or even Clarkeian hibernation a la 2001. The electrochemical instantaneous makeup of a person is definitely impacted by sleep, but we are definitely not conserving metabolic resources when we sleep. We may need fewer calories to survive, but even in sleep we consume at a finite rate. It may be that we are ideally dreaming beings who have to periodically wake up in order to prepare for sleeping, but that is a separate metaphysical question.
The analogy with Clarke is apt: Clarke has been widely hailed as having "forseen" the satellite, http://lakdiva.org/clarke/1945ww/ but his predictions for what space travel would be like in the future have not come to pass on his timeline. It's easy to prognosticate about the future when you have no skin in the game.
As for "stasis", think about what that means. This is a classic problem with "transporter" mechanics: the amount of bandwidth required to transmit exact physical characteristics of a person and move them to another location is the same with keeping them in the same physical state indefinitely in the same location.
The body is an extremely efficient copying machine. Many of the cells of the body are completely replaced every 20 years, many more frequently, and yet we still age and die. I have argued against the shoddy science of much of the "life extension" program of some, such as SENS, in http://www.quora.com/TheExomeExperience/Telomerase-and-aging-part-2 The real question would be, if you were like a record on 78 and had the option of living like you were on 33 1/3 (?: http://en.wikipedia.org/wiki/Gramophone_record for you kids) would you do it? What do you gain for living the same amount of life except on slow? there are real unanswered emotional and psychological impacts to longer term hibernation, and until people can demonstrate that a barbituate coma or some other sort of procedure allows me to live a substantially longer period of time on "slow" compared with a reasonable control, I seriously doubt our ability to devise a means of slowing us down that doesn't have unintended, life-shortening side effects.
Longitudinal studies are notoriously difficult. There's very few of them, they are immensely expensive to conduct. Yet, long term observation of the outcomes of various "preservation" techniques have yet to demonstrate any clear results on humans beyond the 90-110 year life span. If it could be done "naturally", why has it never been documented? If it is done through some mechanical or chemical means, why would we not necessarily be robbing peter to pay paul? The psychological effects of long term hibernation are well-argued in a novel by, of all people, L. Ron Hubbard: http://en.wikipedia.org/wiki/To_the_Stars_(novel) Here, he uses time dilation as the mechanism for indefinite hibernation, something we can think of as "possible using current known technology", despite cost.
I would argue that economically, we don't have the will or the means to conduct the scale of experimentation necessary, and that Terrence Reed might have a good point about the ethical conundrums.
I would say that his answer evokes the charlatainery of current "cryonic" methods, freezing people in liquid nitrogen. The idea that we currently have the technology to suspend indefinitely and reanimate someone, which relies on a distant future where the cause of death (and any subsequent injury from freezing) can be reversed, is impossible because all accounting of such a procedure is unsupportably reduced to an economically free scenario by most current implementation schemes. They can fund you frozen, but there will be no funds left to pay for your revival.
(to part 2...)