This month, the world’s first attempts at placing humans in suspended animation using a new technique will take place at the UPMC Presbyterian Hospital in Pittsburgh, Pennsylvania — not for space travel, but to save lives.
The technique will initially be used on 10 patients whose wounds would otherwise be lethal in an attempt to buy the surgeons some time. It works, as suggested by science fiction, by cooling the body — but not by applying an external temperature change.
Instead, a team of surgeons will remove all of the patient’s blood, replacing it with a cold saline solution. This will cool the body, slowing its functions to a halt and reducing the need for oxygen. Effects similar to this have been seen in accidents: Swedish Anna Bågenholm survived trapped under a layer of ice in freezing water for 80 minutes in a skiing accident; Japanese Mitsutaka Uchikoshi survived 24 days without food or water by entering a state of hypothermic hibernation.
“We are suspending life, but we don’t like to call it suspended animation because it sounds like science fiction,” Doctor Samuel Tisherman, the surgeon who will lead the trial, told New Scientist. “So we call it emergency preservation and resuscitation.”
The technique was developed by Doctor Peter Rhee, who successfully managed to test it on pigs in the year 2000. In 2006, Dr Rhee and his colleagues published the results of their subsequent research. After inducing fatal wounds in the pigs by cutting their arteries with scalpels, the team replaced the pigs’ blood with saline, which lowered their body temperature to 10 degrees Celsius.
All of the control pigs, whose body temperature was left alone, died. The pigs who were warmed back up at a medium speed demonstrated a 90 percent survival rate, although some of their hearts had to be given a jump start (the pigs that were warmed up slow and fast had a 50 and 30 per cent survival rate respectively). Afterwards, the pigs demonstrated no physical or cognitive impairment.
The technique, therefore, will only be used as an emergency measure on patients who have suffered cardiac arrest after severe traumatic injury, with their chest cavity open and having lost at least half their blood already — injuries that see only a seven percent survival rate. The survival rate of these patients will then be measured against a control group that has not received the treatment before further testing can begin.
It’s not science fiction quite yet — a human body can only be safely placed under these conditions for a maximum of a few hours — but even if it raises the survival rate just the little, it will be a massive step forward.
If you want to know more about the trial, or opt out, you can do so on the Acute Care Research website.