Cryostasis Recovery Syndrome
Cryostasis recovery syndrome, or CRS, is a potentially fatal condition that sometimes arises in the aftermath of a person's period in cryostasis.
Under normal conditions, freezing a mammalian body causes widespread tissue injury resulting in death. One cause of this is the tendency of water to expand and form crystals when frozen, bursting cell membranes and tearing apart tissues in the body. To ameliorate this, those expecting to be frozen for therapeutic (i.e. restructuring) or life extension (i.e. aboard 'sleeper ships') purposes must first undergo cryoprotectant therapy, which gives their body the ability to enter hibernation and produce cryoprotectant chemicals in the manner of polar sea creatures. Cryoprotectant therapy is not perfect, however, and it is possible for either the gene therapy, the initial biochemical profusions to fail due to a variety of factors, including immune reaction from the host, insufficient time between administration and freezing, or undetected circulatory problems, among others. In this case, some parts of the body freeze safely while others undergo crystallization, creating localized lesions that may or may not impinge on vital organs. If a frozen person's new hibernation genes don't take effect, the freezing may cause severe metabolic imbalances that may not be compatible with life once the victim is thawed. Alternatively, the cryonic solution profusion process at the start of a freeze may fail for some of the same reasons, resulting in an inconsistent cooling rate throughout the body. In this case, mechanical deformation may occur as some body structures undergo thermal contraction. Filled teeth and bones with metallic implants are particularly vulnerable to this effect. The drastic reduction in cardiopulmonary activity may also result in hypoxia in the brain and other vital organs, causing hypoxia and subsequent lesions in the tissue. Finally, in rare cases, the duration of the freeze and conditions encountered during the freeze can also cause CRS. Radiation typcially damages fast-reproducing cells the most, meaning that frozen people have a higher resistance to the radiation encountered during intersellar travel; cryogenic freezing essentially replaces the effects of a long-term chronic dose with a single, accute dose felt when the patient is thawed. Thus, even though they are asleep and bathed in cryogenic solutions, cryogenic habitation modules should still be built within a strong biowell. Even when protected from environmental radiation, however, the radioactive decay of atoms within ones own body can still cause problems for a cryostasis patient. For example, the decay of bodily potassium-40 and carbon-14 nuclei is not inhibited by freezing, meaning that biomolecules including these atoms can be disrupted and will not be subsequently repaired or replaced for the duration of a freeze.
Severe cases of CRS result in the patient simply not 'waking up' once thawed. They may be in a coma or too severely injured by their experience to go on living. In these cases, supportive care may be provided, but the fact that the initial freeze failed often means that a subsequent freeze for a life-saving restructuring is not likely to improve the prognosis. In most cases, the patient will awaken with signs of varying degrees of organ damage. Signs of neurological damage are the most common; the brain is one of the most likely tissues to resist the gene therapy or the later cryogenic profusions due to the effect of the blood-brain barrier, and any reduction of oxygen as part of the freezing process can have dire consequences. Loss of function, including partial or complete paralysis, psychiatric changes, kidney failure, and infertility are occasionally observed in CRS patients. For those who retain consciousness, CRS symptoms include lethargy and a surprising dearth of pain at first - after all, dead nerve endings send no signals. The recovery process, however, is said to be extremely painful as nerve endings warm up and blood circulation returns to normal.
Treatment for CRS as a whole is supportive and palliative in nature, but some of the underlying conditions, such as radiation sickness or localized organ injury, can be treated individually using existing medical technology. For example, a patient whose limbs become paralyzed as a result of cryogenic injury to nerve tissue can undergo cybernetic prosthesis or even augmentation to restore loss of function. For more generalized effects, a period of rest and observation is indicated.
As a multifaceted syndrome with many different etiologies, the prognosis of patients with CRS varies greatly based on the extent of initial injuries. Failure to regain consciousness after a freeze indicates significantly poorer outcomes, with most of these patients ultimately falling into a vegetative state or succumbing to their injuries. For others, Cobalt Protectorate medical technology is so advanced that, with varying amounts of cybernetic surgery, recovery is possible if not quick or inexpensive.
Rigorous adherence to cryoprotectant therapy protocol, including industry-standard wait times between the conclusion of therapy and one's first freeze, is crucial to mitigating the risks of cryostasis. Tissue samples and gametes may be taken from a canditate before cryostasis and frozen in separate, radiation-hardened compartments to give CRS treatments a better chance of success when the patient is thawed. Once someone has shown signs of acute CRS, they are generally advised to never enter into cryostasis ever again. There is evidence that another complete round of cryoprotectant therapy may allow these people to make another attempt at it, but the risks are generally considered to outweigh any possible reward.
At present, there is a cumulative 1% chance per 5 years spent in cryostasis that an individual will not wake up from cryostasis due to CRS. Every 10 years, a patent should be thawed and allowed to heal to keep this risk as low as possible. Those who awake on an interstellar journey with signs that they will not survive another freeze are generally given the option to become part of their mission's permanent crew rotation. Mission planners are encouraged to build extra capacity into their life support systems to, among other things, account for this expansion of active crew. On missions where every resource (i.e. atmosphere) is tightly budgeted, waivers should be signed before a freeze indicating that the patient accepts the risk that they may not wake up from a subsequent freeze.
For Evermornans and other human-descended spaceborne cultures, death by CRS is, for obvious reasons, regarded as a gruesome and frightening way to die. The cold calculus involved in risking a refreeze (see Epidemiology) versus risking the long-term viability of a mission is horrific to most cultures that value individual life, as it means asking a person to potentially suffer, die, or face life-changing injury so that the rest of the sleepers can survive on to the destination. As a form of gallows humor, waking crews aboard sleeper ships are known to place bets on the number of people to succumb to CRS during a given voyage. Particularly brave or ghoulish cryostasis patients have even been known to place bets on their own survival in these pools, emerging from sleep a wealthier person - or not at all. Doing this as either a patient or an outside observer is considered highly uncouth in Evermornan culture, but among the more mortality-concious Lepidosians, it is considered an acceptable bargain with Raikep, their god of life and death.