Imagine a loved one was just rushed to the hospital. They were caught in an armed robbery and suffered a gunshot wound. They have critical injuries but they’re losing too much blood too fast. Until very recently, the chance of them surviving in this condition would have only been about 7%. But a group of doctors at the University of Pittsburgh hospital have recently started doing something incredible to save these types of patients: they’re putting their bodies in a state of suspended animation and then bringing them back to life.
Patients with gunshot or stab wounds lose a lot of blood at the onset of the injury. By the time they get to the hospital, their heart has usually stopped beating. When the heart stops beating, blood stops flowing through the body and the various organs no longer receive all the nutrients they need.
This is particularly bad for the brain, which requires substantial levels of oxygen and glucose. In fact, it only takes a few minutes without oxygen before the brain is irreversibly damaged.
So doctors need to get that heart restarted — fast! But patients in these conditions also suffer from wounds that need immediate attention. In the worst cases, doctors just don’t have enough time to take care of the wounds before the patient dies from loss of blood.
But the Pittsburgh doctors have an amazing alternative that has the potential to save hundreds of lives.
A cool alternative
In order to buy some time and keep the brain damage-free, patients in this condition are treated with what the doctors are calling a “preservation technique”. A catheter is threaded into the patient’s aorta — the main artery of the heart. Their blood is drained out and stored, and cold saline solution — essentially salt water — is passed through the catheter. As the saline circulates, it fills the patient’s entire body and cools them down from 37 ºC to 10 ºC in just 15 minutes.
When the process is complete, the patient is empty of blood, unable to move or breathe. As far as medicine is concerned, they are clinically dead.
So how does cooling a patient down help doctors save their life?
You’ve suffered a gunshot wound. You’re losing blood and your organs are failing. Would you let doctors drain your blood and chill your body to 10 ºC, entering a state of suspended animation, to buy precious time that may save your life? Image credit: US Navy via Wikimedia Commons
Buying time
Well, when the body is lowered to cooler temperatures all of the chemical reactions that go on inside it slow down. This means the cells require a lot less oxygen to survive and can work with what they’ve got for longer.
Once the patient’s blood is replaced with cold saline solution and their bodies have cooled, surgeons have about an hour to fix the worst wounds. When that time is up, the blood is pumped back into the patient, their heart is restarted, and they are slowly brought back to normal temperature.
The preservation technique is now in a trial phase at the University of Pittsburgh Medical Center in Pennsylvania, USA. A patient suitable for the trial will have arrived at the hospital after a traumatic injury leading to cardiac arrest. They will likely have lost half of their blood supply and initial attempts to restart their heart will have failed.
Ethics…? schmethics!
The preservation technique has raised a few ethical concerns, particularly that patients would not be able to consent to this radical procedure. But the United States Food and Drug Administration, the body that has approved this procedure, often lifts the need for patient consent in the event of life-threatening situations.
The Pittsburgh community has also been raising awareness. Members of the community have been urged to request special arm-bands that indicate to doctors that they do not consent to the procedure. But so far, no one has requested to opt out.
What would you want to do if this was you? Would you die to stay alive?
Espresso Science 
