13. March 2009 · Comments Off on Evidence based cryonics · Categories: Cryonics · Tags: , , , , , ,

Cryonics patients can greatly benefit from rapid stabilization after pronouncement of legal death. One fortunate feature of stabilization procedures is that the most effective and validated procedures are relatively inexpensive and easy to perform.  The difference between no stabilization procedures at all and procedures that aim to rapidly restore blood circulation and drop the patient’s temperature is likely to be bigger than that between such basic stabilization and procedures that include administration of a large number of medications and remote blood washout.  This observation gains even more importance when it is considered that there is a serious lack of empirical data to support these more advanced procedures.

To date, no single neuroprotective agent has been approved for the treatment of global or focal ischemia. Despite this fact, cryonics organizations like Alcor and Suspended Animation administer an unorthodox number of medications to protect the brain and prevent impairment of circulation. While there are peer reviewed papers that combine a number of medications, there is no precedent in mainstream medicine or biomedical research in using such a large number of medications (in contemporary cryonics, medications protocol exceeds 12 different drugs and fluids). The only existing justification for using current protocol reflects work done at Critical Care Research in the 1990s. Although scattered reports exist about the effectiveness of this protocol in resuscitating dogs from up to 17 minutes of normothermic global ischemia, no detailed (peer reviewed) paper has been published about these experiments.  Another concern involves the extrapolation of these findings to cryonics. It would go beyond the general nature of this piece to document all the differences between these controlled experiments and cryonics as practiced in the real world, but suffice it to say that the factors of shorter and longer delays, longer  drug administration times, suboptimal “post-ischemia” circulation, and induction of hypothermia introduce many unknowns about the efficacy of these drugs for cryonics patients.  In the case of some medications, like streptokinase, heparin, and dextran 40, a case could be made that the potential benefits outweigh the unknowns, but should this argument be extended to all medications?

Even more complexity is introduced when cryonics organizations make an attempt to wash out the blood and substitute it with a universal organ preservation solution. The rationale for this procedure is found in conventional organ preservation and emergency medicine research. The question in organ preservation research is no longer whether hypothermic organs benefit from blood substitution with a synthetic solution, but what the ideal composition of such a solution should be. In emergency medicine research asanguineous hypothermic circulatory arrest is increasingly being investigated to stabilize trauma victims. But it is a major step from these developments to the practice of remote blood washout of ischemic patients with expected transport times of 24 hours or more. At present the only sure benefit of remote blood washout is that it enables more rapid cooling of the patient, a benefit that should not be underestimated. But when liquid ventilation becomes available to cryonics patients, rapid cooling rates will be possible without extracorporeal circulation.

The lack of relevant published data to support the administration of large numbers of drugs and remote blood washout in cryonics is not just a matter of risking performing redundant procedures. A lot of time and resources are being spent in cryonics on obtaining and maintaining equipment and supplies for these procedures, in addition to the licensing fees paid to use some of these technologies and the training and recruiting of people to perform them. But perhaps the most troublesome problem is that the preparation and execution of these procedures during actual cryonics cases can seriously interfere with rapid and effective cardiopulmonary support and induction of hypothermia.

There is an urgent need to move from extrapolation based cryonics to evidence based cryonics. This will require a comprehensive research program aimed at creating realistic cryonics research models. It will also require vast improvements in the monitoring and evaluation of cryonics cases.  The current debate should no longer be between advocates and opponents of standby and stabilization but about what stabilization procedures should be used by cryonics organizations given our current knowledge.

Viewing cryonics as an experimental medical procedure does not necessarily commit one to the position that substantial amounts of money and resources should be allocated to recruiting medical professionals and expensive equipment. The most common sense implication of the views outlined above is that the most effective measures to improve the care of cryonics patients are encouraging members to relocate to the area of their cryonics organization, improved health tracking of existing members, and cryonics training aimed at teaching the basic procedures and techniques that confer real evidence based benefits.