At some point, everyone's heart will stop. For most, this is when they begin to die. Doctors succeed in very few cases at bringing the clinically dead back to life. However, more patients could be saved if medical professionals put existing knowledge about the treatment of cardiac arrest to better use, argues critical care physician Sam Parnia, 41, who is leading a revival of research in this field at the Stony Brook University School of Medicine in New York.
When Parnia was a student some 20 years ago, a patient he knew well died under his care. It was a key moment for the young doctor, who has since sought to understand and fight the process of death.
SPIEGEL: Dr. Parnia, in your new book on resuscitation science, "Erasing Death," you state: "We may soon be rescuing people from death's clutches hours, or even longer, after they have actually died." That sounds a lot like resurrection. Is this a serious claim?
Parnia: In the past decade we have seen tremendous progress. With today's medicine, we can bring people back to life up to one, maybe two hours, sometimes even longer, after their heart stopped beating and they have thus died by circulatory failure. In the future, we will likely get better at reversing death. We may have injectable drugs that slow the process of cell death in the brain and other organs. It is possible that in 20 years, we may be able to restore people to life 12 hours or maybe even 24 hours after they have died. You could call that resurrection, if you will. But I still call it resuscitation science.
SPIEGEL: With all due respect, this discipline has a dismal record. Survival rates for out-of-hospital cardiac arrests continue to be poor and have barely improved from what they were 25 years ago.
Parnia: Sadly, that's correct. There is no generally enforced standard of care. In some communities in the United States, survival rates after resuscitation are as low as close to 0 percent. In general, we are better at rescuing people who suffer cardiac arrest in hospitals. But even in this group the average now in the US is 18 percent. The United Kingdom has 16 percent and I assume German hospitals have a similar rate.
SPIEGEL: That's shockingly bad.
Parnia: Here in Stony Brook we had a 21 percent survival rate when I first arrived. Now, two years later, we are at 33 percent. In the first quarter of this year, our latest available data shows that we reached 38 percent, which likely puts us among the top hospitals in the US. Most, but not all of our patients, get discharged with no neurological damage whatsoever.
SPIEGEL: Are you some sort of a magician?
Parnia: Not at all. We work strictly according to the recommendations of ILCOR, the International Liaison Committee on Resuscitation. We have taken some things even a bit further. ILCOR publishes their consensus findings every five years, most recently 2010. But the problem is: Most hospitals have not fully implemented all their findings.
Parnia. That's exactly why I have written this book. I want to shine a light on the fact that resuscitation science has advanced tremendously over the last 20 years, yet the implementation of this knowledge remains very poor. This is costing us many lives every year.
SPIEGEL: Is this due to a lack of understanding on the part of doctors?
Parnia: Apparently. A recent study found that the optimal length of resuscitation to yield higher survival is at least 40 minutes. Yet most doctors will stop within 20 minutes. They don't try as hard because they wrongly think the brain will be damaged by then or that it will be pointless to continue.
SPIEGEL: Why are the findings of such studies not put into practice?
Parnia: Resuscitation has gone from something every doctor does every now and then to a highly specialized and complicated field, much like cardiology. Yet that is not generally recognized. As long as hospitals don't require their resuscitation doctors to implement all the nuances required to save brains and lives after cardiac arrest through fully trained specialists, survival rates in general will not improve. I think we need more regulation by state or medical authorities. That's the only way to reach higher standards. We can't go on with a situation where hospital or individual physicians decide for themselves what part of the guidelines they implement or not.
SPIEGEL: Basic first aid teaches us that the brain is very fragile. Three to five minutes after the heart stops, the brain incurs permanent damage due to lack of oxygen.
Parnia: This is a widely-held misconception, even among doctors. It's mostly based on research done in the 1940s, 1950s and 1960s. In those days, doctors concluded that brain cell death was inevitable in such a short time. Now we know that if treatment is correct, it really can take hours for brain cells to die. And only if all the treatments that we know today are not implemented, the damage can become apparent after as little as five minutes without blood flow. Part of the problem is that we all live in the past -- patients, doctors, nurses and legislatures. We have preconceived ideas about death. For thousands of years, death was a clear, precise moment: The heart stopped beating, and that was it. Nothing could be done from then on. You either were alive or not. But since the arrival of CPR (cardiopulmonary resuscitation) more than 50 years ago, we know that this view is no longer correct. Death is not a fixed moment anymore. From a cellular perspective, it is a process that proceeds at various speeds in the different tissues of the body after the heart stops.
SPIEGEL: And that process is, in your words, fully reversible?
Parnia: Of course, it is of paramount importance to protect the brain. CPR as early as possible after cardiac arrest is essential. But the really dangerous period for brain is only after you restart the heart and get the person back to life. It is then that you start getting major brain damage. One of the reasons for this is that when you restart blood flow to the brain, which hasn't seen any blood for a while, the oxygen itself becomes toxic. The brain can become very swollen and inflamed and at the same time, blood flow to the brain drops to dangerously low levels. The brain also becomes perilously starved of oxygen and nutrients. Consequently, most brain damage after resuscitation occurs not within the first few minutes of death, but in the hours up to the first 72 hours after resuscitation. But with proper post resuscitation care, we can minimize that.
SPIEGEL: What exactly happens once the heart stops?
Parnia: A person immediately loses consciousness, breathing stops as well, and within seconds, the brain ceases working, even at the very basic level of the brain stem. The pupils become fixed and dilated. The EEG shows a flatline. This person is now dead, yet in what we may call the early stages of death. He is a corpse, and in a hospital setting might now be certified dead and sent to the mortuary.
Parnia: That depends on what caused the person to die, what caused his cardiac arrest.
SPIEGEL: What can you do to potentially bring him back to life?
Parnia: It is a chain of interventions, and everything we do counts. One error somewhere along the line, and he will stay dead or live with brain damage. We start with chest compressions as early as possible, first by hand, then by a machine, because in general human beings cannot administer this to the required standards for more that just a few minutes. At the same time we provide breaths via an ambu bag -- not more than 8 breaths per minute. Even this simple exercise is often done wrong in many cases. Once you pump too much air into the body, it squeezes the heart, and it won't start again. This itself can kill people -- or in this case, keep them dead.
SPIEGEL: What are some of the newer interventions that you'd recommend?
Parnia: We cool the body down, from 37 degrees to somewhere between 32 and 34 degrees. I usually go to 32 degrees. Patients stay at this temperature for 24 hours or so. Cooling has a lot of positive effects. It reduces the amount of oxygen the brain needs, it prevents dangerous chemicals like hydrogen peroxyde from forming and it slows down the process of cell death. Even this really critical part of resuscitation is not done routinely, not even in places where its benefits are known, including Germany. At times it has been reported to be used by less than 50-60 percent of hospitals.
SPIEGEL: How do you cool a body?
Parnia: We use pads that get attached to the thighs and the upper body. In a matter of hours, the cooling machine brings the body temperature down to the desired level. But you could also do this at home, if you found someone there in cardiac arrest. Call an ambulance, administer CPR and place a bag of frozen peas or other frozen vegetables on the patient. It helps to protect the brain.
SPIEGEL: What do you do that is not regularly done?
Parnia: Among other things, we check continuously how much blood and oxygen gets to the brain. If we have at least 80 percent of normal levels, the person tends to do better. If his condition doesn't improve, we follow steps that includes the use of an automatic machine to give compressions and breathing and eventually put him on ECMO. These are two catheters, one at the groin, one at the neck. It is basically a shortcut for the heart: The blood gets oxygenated outside of the body and pumped back in. It is more widely used in Japan and South Korea, and doctors there have found that their survival rates have increased when ECMO is used with the right patients. But most ICUs in the world still don't use it.