My colleague Paul Seaburn recently wrote about UPMC Presbyterian Hospital's Emergency Preservation and Resuscitation for Cardiac Arrest from Trauma (EPR-CAT) program, which may keep trauma victims alive by switching out their blood with a chilly saline solution, placing them in suspended animation at about 50 degrees below normal body temperature (stopping the heart, breathing, and other metabolic activity), and resuscitating them after their wounds have been repaired. It's been tried with other mammals, where it works about 90% of the time.
But if these trials somehow fall through, there's another option. Mark Roth of the Fred Hutchinson Cancer Research Center has figured out a way to temporarily eliminate the demand for oxygen in mammals using hydrogen sulphide, which would then allow more time for suspended animation (by the above method, or by others). This method also has a high rate of success, as Roth explains here:
The odds that neither method will succeed, when they have such a high rate of success in other mammals, are very slim. In other words: at some point within the next ten or twenty years, it's probable that suspended animation is going to be a thing that regularly happens, at least during trauma care and major surgery. And if a completely reliable method of suspended animation can be developed, it will completely transform the latter—changing surgery in much the same way anesthesia did. Surgeries that would be too radical to contemplate today may be low-risk procedures if performed during suspended animation (where there's no risk of cardiac arrest, blood loss, stroke, and so forth), and future surgeons may one day marvel at the fact that today's surgeons were able to do so much without putting the patient's body on pause.