It’s not suspended animation for space travel, it’s not cryonic preservation/resuscitation, and it’s not like that Captain America guy on ice, but the trials of the EPR-CAT (Emergency Preservation and Resuscitation for Cardiac Arrest from Trauma) study that began this month at the University of Pittsburgh Medical Center is certainly a step towards the science fiction outcomes we all know and love.
The research will be performed on 10 patients with traumatic gunshot or knife wounds – wounds severe enough that they victim has a less than 10% chance of surviving. As seen in injuries of this severity, the blood loss is so great that it pushes the heart into cardiac arrest. In the patients who will receive the treatment, a team of surgeons will remove the patients blood and replace it with chilled (50 F) saline. The decrease in temperature will slow the body’s metabolic functions and reduce the need for oxygen.
According to lead researcher, Dr. Samuel Tisherman, the cooling will be accomplished in 15 – 20 minutes after the saline catheter is placed in the aorta of the victim. Initial priority is given to flushing the blood from the brain and heart – organs most sensitive to low oxygen in the blood. Once the heart and brain are “clean” the rest of the body is similarly flushed. As New Scientist explains, once the surgeons have removed the blood, there will be no breathing and no brain activity – the patient will be clinically dead.
Once the patient has reached this state, the clock starts ticking. As Tisherman says, the surgeons will have 45 minutes to a maximum of two hours to control the bleeding of the patient and repair the damage to the circulatory system. During this time, at the lowered temperature, the patient’s cells will produce any energy needed via anaerobic glycolysis.
Following the surgery, blood is pumped back in to replace the saline. At that point, the heart may restart by itself, or as in a trial performed by Dr. Peter Rhee on pigs, the heart may need a restart by the surgical team. The patient’s body will then be warmed slowly to normal body temperature.
Currently, surgeons who are able to perform this process are on call at UPMC. The goal is to perform EPR-CAT on ten patients who meet the criteria above, and compare the survival rates with ten patients who suffered similar injuries but did not relieve EPR-CAT because the team was not present when the patient was brought to the hospital.
As Tisherman told New Scientist, after the initial trial, the results will be refined and performed on another ten patients
A major sponsor of Dr. Tisherman and his co-investigator Dr. Patrick Kochanek is the U.S. Department of Defense which is interested in adapting EPR-CAT to battlefield conditions, buying wounded soldiers time until they can be treated by field surgeons.
Dr. Tisherman explains the process in more detail in the video below.
More:
National Geographic: Surgeons to Put Gunshot Victims into Suspended Animation
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