Suspended animation. It’s a concept that’s been proposed in science fiction for decades. But in reality? Long considered impossible, doctors in the United States have now managed to put a human into suspended animation long enough to conduct surgery.
Dr. Samuel Tisherman is a trauma surgeon at the University of Maryland School of Medicine. He leads the team that reports implementing the technique. The official scientific name of suspended animation is emergency preservation and resuscitation, or EPR. It has been attempted only under the most traumatic situations, such as when a patient arrives at Baltimore’s Maryland Medical Center in cardiac arrest following a life-threatening injury or wound.
Putting a patient into EPR involves rapidly lowering the body temperature to a frigid 50 degrees Fahrenheit. (For comparison, normal body temperature is almost twice that at 98.6 degrees. When a person’s core body temperature drops below 95 degrees, hypothermia has set in.) Doctors do this by replacing the patient’s entire blood volume with a chilled saline solution. Brain activity almost ceases—but just temporarily. The medical team then has up to 120 minutes to repair the devastating wound and restore heart and brain function while the patient is in this suspended state. Under normal trauma situations of this severity, doctors would have only five minutes or less to work.
How does EPR work? God designed all the cells in our bodies to need a constant supply of oxygen. When the heart stops beating, blood no longer carries new oxygen to the cells. The brain can survive only about five minutes without fresh oxygen before damage begins to occur. But dropping the body temperature so drastically slows or completely stops the chemical reactions that are normally happening within cells. This means little or no oxygen is needed—for a short time. The entirety of the body’s functions are suspended.
The process isn’t yet perfected. Resuscitating the patient has its own risks. As the body warms and blood is restored, patients can experience a type of cell damage called reperfusion (return of fluid to the cells) damage. Limited evidence suggests that this damage is greater the longer a person has been under EPR.
Unlike the typical sci-fi plot, Tisherman’s goal is not to extend human life for long voyages to populate distant planets in outer space. Instead, he simply wants to buy time to save human life right here on Earth.
