Doctor: Many people can be saved hours after cardiac arrest
Sunday , March 31, 2013 - 7:26 AM
Sam Parnia, director of resuscitation research at Stony Brook University School of Medicine in New York and author of “Erasing Death: The Science That Is Rewriting the Boundaries Between Life and Death,” believes that we can bring many more people back to life after they die — it’s just a matter of training and equipment.
In an interview, he elaborated on this provocative idea. Here is an edited excerpt:
Q: Are the people you resuscitate after cardiac arrest really dead? Isn’t the definition of death that it is irreversible?
A: A cardiac arrest is the same as death. It’s just semantics. After a gunshot wound, if the person hemorrhages sufficiently, then the heart stops beating and they die. The social perception of death is that you have reached a point from which you can never come back, but medically speaking, death is a biological process. For millennia we have considered someone dead when their heart stops beating.
Q: What is the biggest problem in bringing someone back to life?
A: Reversing death before the person has too much cell damage. People die under many different circumstances and under the watch of many different medical specialists. No single speciality is charged with taking and implementing all the latest advances and technology in resuscitation.
Q: How long after they die can someone still be resuscitated?
A: People have been resuscitated four or five hours after death — after basically lying there as a corpse. Once we die, the cells in the body undergo their own process of death. After eight hours it’s impossible to bring the brain cells back.
Q: What is the best way to bring people back?
A: The ideal system — and they do this a lot in Southeast Asia, Japan and South Korea — is called ECPR. The “E” stands for extracorporeal membrane oxygenation (ECMO). It’s a system in which you take blood from a person who has had a cardiac arrest and circulate it through a membrane oxygenator, which supplies oxygen and removes carbon dioxide. Then you pump the blood back into circulation around the body. Using ECMO, they have brought people back five to seven hours after they died. ECMO is not routinely available in the U.S. and U.K., though.
Q: So, when I go into cardiac arrest, ideally what steps do I want my doctors to take?
A: First, we start the patient on a machine that provides chest compressions and breathing. Then we attach the patient to a monitor that tells us the quality of oxygen that’s getting into the brain.
If we do the chest compressions and breathing and give the right drugs and we still can’t get the oxygen levels to normal, then we go to ECMO. This system can restore normal oxygen levels in the brain and deliver the right amount of oxygen to all the organs to minimize injury.
At the same time, you also cool the patient. This slows the rate of metabolic activity in the brain cells to halt the process of cell death while you go and fix the underlying problem.
Q: How do you cool the body?
A: It used to be ice packs. Today, a whole industry has grown up around this, and there are two methods. One is to stick large gel pads onto the torso and the legs. These are attached to a machine that regulates temperature. When the body reaches the right temperature, it keeps it there for 24 hours. The other way is to put a catheter into the groin or neck, and cool the blood down as it passes by the catheter.
Cooling benefits the heart and all the tissues, but we focus on the brain. There are also new methods in which people are cooled through the nose. You put tubes in the nostrils and inject cold vapor to cool the brain down selectively before the rest of the body.
Q: If I had a cardiac arrest today, what are the chances I would get all of that?
A: Almost zero.
Q: In your book, you imply that death might be pleasant. Why do you think that?
A: The question is: What happens to human consciousness — the thing that makes me into who I am — when my heart stops beating and I die?
From our external view, it looks like it simply disappears. But it sort of hibernates, in the same way as it does when you are given a general anesthetic. And it comes back. I don’t believe that your consciousness is annihilated when you reach the point of death. How far does it continue? I don’t know. But I do know that at least in the period of time in which we can bring people back to life, that entity of the human mind has not been annihilated.
Q: What does this mean?
A: Those people who have pleasant experiences after death suggest that we should not be afraid of the process. It means there is no reason to fear death.