E.P.R., or emergency preservation and resuscitation, has long been proved successful in animal experiments, but overcoming the institutional, logistical, and ethical obstacles to performing it on a human being has taken more than a decade:
When [the first patient to undergo E.P.R.] loses his pulse, the attending surgeon will, as usual, crack his chest open and clamp the descending aorta. But then, instead of trying to coax the heart back into activity, the surgeon will start pumping the body full of ice-cold saline at a rate of at least a gallon a minute. Within twenty minutes (depending on the size of the patient, the number of wounds, and the amount of blood lost), the patient’s brain temperature, measured using a probe in the ear or nose, will sink to somewhere in the low fifties Fahrenheit.
At this point, the patient, his circulatory system filled with icy salt water, will have no blood, no pulse, and no brain activity. He will remain in this state of suspended animation for up to an hour, while surgeons locate the bullet holes or stab wounds and sew them up. Then, after as much as sixty minutes without a heartbeat or a breath, the patient will be resuscitated. A cardiac surgeon will attach a heart-lung bypass machine and start pumping the patient full of blood again, cold, at first, but gradually warming, one degree at a time, over the course of a couple of hours. As soon as the heartbeat returns, perhaps jump-started with the help of a gentle electric shock, and as long as the lungs seem capable of functioning, at least with the help of a ventilator, the patient will be taken off bypass.
Even if everything works perfectly, it will take between three and five days to determine whether the patient’s brain has been damaged, and, if so, to what extent. There will be more surgeries, followed by months of rehabilitation.
You can see why the homicide rate keeps going down.