A groundbreaking procedure which could increase emergency surgery time by 2 hours has been trialed in the US. The new technique called “suspended animation” aims to heal traumatic injuries that would usually cause death.
The technique is being tested at the University of Maryland Medical Centre in Baltimore. The new procedure officially called “emergency preservation and resuscitation (EPR)” is being trialed on patients with acute trauma such as stab or gunshot wounds, that have lead to cardiac arrest. The patients will have lost more than half of their blood and their heart will have stopped beating. It will be used when surgeons feel they only have minutes to operate, and the patient has less than 5 percent of survival.
During ERP, surgeons rapidly cool the patient’s body to 10 to 15°C. This is done by replacing their blood with an ice-cold saline. During the procedure, the patient’s brain activity is close to stopping. They then disconnect their body, which would usually be classified as dead from the cooling system. The team then has 2 hours to perform the surgery, before they warm up the body and the heart is restarted.
“A Little Surreal”
Samuel Tisherman, from the University of Maryland School of Medicine, told New Scientist that his team have placed at least one patient in ERP, commenting that it is “a little surreal”. He did not reveal how many people had survived the procedure, and says he plans to share the results of the trial by the end of 2020
Suspended animation was given the green light by the US Food and Drug Administration (FDA). Due to the urgency of the treatment, the FDA have given permission for the surgeries to take place without consent. The team discussed this with the local community, describing the trial and giving them a chance to opt out.
Tisherman’s interest in this field was due to an incident in his early career when a young man was stabbed in the heart, in a fight over a pair of bowling shoes. “He was a healthy young man just minutes before, then suddenly he was dead. We could have saved him if we’d had enough time,” he says. This led him on a quest to investigate pioneering new surgery techniques that would allow surgeons more time in emergency situations.
How long you can keep someone in ERP is still not yet clear. When a person’s cells are cooled and then warmed up, they have the potential to experience reperfusion injuries which damage the cell. The longer the patient goes without oxygen, the more likely damage will occur.
The team claim, it may be possible to give medication to minimise these injuries and extend the time the body can remain cooled, says Tisherman, “but we haven’t identified all the causes of reperfusion injuries yet”.
Tisherman shared the team’s progress at the New York Academy of Sciences. Ariane Lewis, director of the division of neuro-critical care at NYU Langone Health, said she thinks it is important work, but it was just the first steps. “We have to see whether it works and then we can start to think about how and where we can use it.”
IMAGE CREDIT: Ratthaphon Bunmi