New definition of ‘dead': PA doctors to suspend gunshot victims between this life and next
Later this month, New Scientist reports that doctors at the University of Pittsburgh Medical Center’s Presbyterian Hospital will be testing a procedure that will suspend gunshot and knife-wound victims in a state between life and death.
According to Samuel Tisherman, the surgeon leading the trial, although they “are suspending life, we don’t like to call it suspended animation because it sounds like science fiction. So we call it emergency preservation and resuscitation.”
The procedure calls for replacing all of a patient’s blood with a cold saline solution to induce hypothermia. It was first used on pigs in 2002, at the University of Michigan Hospital in Ann Arbor. Massive hemorrhage wounds were inflicted on sedated pigs whose blood was replaced with a cooled saline solution. Their wounds were treated, and as they slowly warmed, the solution was replaced with their blood.
The pigs’ hearts began beating again — typically on their own, but occasionally with electrical aid — and they showed no ill cognitive or physical effects afterwards.
“After we did those experiments, the definition of ‘dead’ changed,” said surgeon Peter Rhee, who helped refine the procedure. “Every day at work I declare people dead. They have no signs of life, no heartbeat, no brain activity. I sign a piece of paper knowing in my heart that they are not actually dead. I could, right then and there, suspend them. But I have to put them in a body bag. It’s frustrating to know there’s a solution.”
“We’ve always assumed that you can’t bring back the dead. But it’s a matter of when you pickle the cells,” said Rhee.
Human trials will have to meet strict criteria. The patient will have to have suffered a cardiac arrest after the gunshot or knife-wound, and must not have responded to conventional attempts to jump-start his or her heart. The chances of survival in such cases are less than 7 percent, so instead of continuing to try to restart the heart, Dr. Tishman and his team will flush cold saline through the patient’s heart and into his or her brain. After 15 minutes, the saline solution will have replaced all the blood in the patient’s body, preventing metabolic reactions from happening, which allows cells to survive without oxygen.
The injuries would then be treated and, as with the pigs, the victim’s blood would slowly be reintroduced to his or body. If the heart doesn’t start on its own, the patient would be resuscitated.
“If a patient comes to us two hours after dying you can’t bring them back to life. But if they’re dying and you suspend them, you have a chance to bring them back after their structural problems have been fixed,” Rhee said.
Whether this procedure will lead to the kind of long-term suspended animation common in science fiction films about interstellar travel is unknown.
“We’re trying to save lives, not pack people off to Mars,” Dr. Tisherman said. “Can we go longer than a few hours with no blood flow? I don’t know. Maybe years from now someone will have figured out how to do it, but it will certainly take time.”
[“Surgery Team Operating In A Surgical Room” on Shutterstock]