For the past 40 years, CPR has been composed of two things—rescue breaths and chest compressions—and this formula for cardiac survival can revive around 25 percent of patients without a pulse. However, emerging evidence suggests there may be a more effective protocol for resuscitation that can save even more lives, and it's simpler than traditional CPR.
Cardiocerebral resuscitation, or CCR, differs from CPR in that for the first 5 to 10 minutes after cardiac arrest, a rescuer does not breathe for the patient at all. Instead, the focus shifts to performing unrelenting chest compressions at a rate of 100 per minute. One clinical trial in Wisconsin showed this technique saved 30 percent more lives when compared with traditional CPR. Better yet, patients who receive CCR instead of CPR were found to be 24 percent more likely to be neurologically intact upon release from the hospital.
"It's one of the first times in medicine something has gotten simpler," says Dr. Amal Mattu, professor of emergency medicine at the University of Maryland Medical Center.
There are two main reasons why it works: One, constant pressure on the chest maintains a constant blood pressure, which insures blood flow to vital organs. In CPR, when a rescuer turns from his chest compressions to give the breaths, the blood pressure quickly drops to near zero and the blood stops flowing to the brain and other vital organs. Blood pressure is built up slowly over the course of the compressions, so when the rescuer returns to them, he or she has to make up for lost time.
Second, ventilations actually counteract the effectiveness of chest compressions. When a rescuer breathes for a patient, he or she forces air into the lungs, which increase the pressure inside the chest. Then, this force squeezes on the veins that return blood to the heart. "That results in less filling of the heart," Mattu says. "If there is less blood coming back to the heart, there is going to be a lower output from the heart, lower blood pressure, lower perfusion of the coronary arteries and the brain." Constant blood flow to the brain increases the chances for survival, and that is one reason why the studies are finding CCR patients to be more neurologically intact. The more time the brain spends without oxygen, the greater the chance for brain damage.
"Chest compressions, early on, are much more important than airway issues. When people are focused on airway issues, they tend to not do as good chest compressions, or their chest compressions are too slow," Mattu says. What rescuers need to realize, he says, is when the heart stops beating due to cardiac arrest, the blood has enough oxygen to support the organs for around 5 or 10 minutes.
Quality chest compressions are just as important as having a defibrillator early on. Dr. Comilla Sasson, professor of emergency medicine at University of Colorado Denver, and her colleagues found when EMS arrives on the scene, doing immediate chest compressions is as beneficial as shocking a patient with a defibrillator right away. Furthermore, they found if the EMS personnel arrived more than 5 minutes after the onset of the cardiac arrest, chest compressions first had a slight advantage.
Currently, CPR certifying organizations, such as the American Heart Association, have yet to include the principles of CCR in their protocols, but Sasson thinks the AHA will probably include some of this research when they meet to discuss their guidelines in November.
When the organization last changed their protocols in 2005, they increased the ratio of compressions to breaths from 15:2 to 30:2, and this year, they may forgo the breathing all together. "Our research right now is showing that chest compressions are the most important thing that you can do," she says. "We are hopeful that the Heart Association will take that to heart."
Most people have an aversion to mouth-to-mouth breathing to begin with, and Sasson speculates that a bystander trained in CCR will be more willing to act than a person who thinks he or she has to breathe for the victim. "The best way to increase bystander CPR rates in the U.S. is to get the message out that hands-only CPR works," she says.
A study published in the July issue of The New England Journal of Medicine found that 911 callers who were given instructions for CCR were more likely to intervene than callers who were given instructions for traditional CPR. Currently, 25 percent of people who receive out-of-hospital CPR will survive. If the studies are valid and CCR can significantly increase this percentage, then a lot more people will survive.
However, CCR is not a panacea. Mattu says this method should only be used with primary cardiac arrest, which means the heart stops pumping blood due to a problem with the heart and not because the patient has stopped breathing. In those instances, positive pressure ventilation is essential. On the other hand, Mattu says about 80 percent of cardiac arrest victims are primary cardiac arrest patients and could benefit from CCR. Additionally, after 5 or 10 minutes of chest compressions, a person will start to need some more air put into their lungs.
Over the past 30 years, prehospital cardiac survival rates have been constant—nine out of 10 people will not survive a cardiac arrest—in spite of all the money and efforts to teach CPR to the public. Currently, only 25 percent of patients receive any out-of-hospital resuscitation at all. Sasson says the combination of the science of CCR and public outreach to teach it is what needs to be done to increase cardiac arrest survival. "I think that is where hands-only CPR can revolutionize the approach to cardiac arrest," Sasson says. "It's a really simple message—pump hard, pump fast."