Because of its importance, the editors of the American Journal of Medicine chose to publish the report online in advance of the journal's April print issue.
"Cardiocerebral Resuscitation eliminates certain previously recommended procedures and reprioritizes the order of actions the emergency medical services deliver," said Michael J. Kellum, MD, leading author of the study report.
Under the new approach, first responders skipped the first steps of the standard protocol: intubating the patient for ventilation and delivering a shock using a defibrillator. While still attaching the victim to a defibrillator, they did not wait for the device to analyze the patient's heart rhythm, but started fast, forceful chest compressions.
"Intubating the patient and waiting for the defibrillator to do its analysis takes time - time a cardiac arrest victim doesn't have," said Gordon A. Ewy, MD, director of the Sarver Heart Center and co-author of the study. "I am convinced that Cardiocerebral Resuscitation will have a world-wide impact."
"In laboratory experiments, we found that the most important factor of survival is to keep the blood moving through the body by continuous chest compressions," said Dr. Ewy, who pioneered the CPR Research Group at the Sarver Heart Center. "Stopping chest compressions for ventilations was far more harmful than helpful. Excessive ventilations during chest compression turned out to be harmful, too."
First responders applying the new protocol were able to resuscitate the majority (58 percent) of out-of-hospital witnessed cardiac arrest victims, provided they had a "shockable" initial heart rhythm. "Shockable" describes a condition in which the heart quivers rather than beats but can be shocked back into normal beat with a defibrillator. In contrast, the survival rate was only 20 percent in the 3 years before, when the standard CPR protocol was used.
The current study, which involved 125 patients, reports the experiences after the revised protocol was implemented in two Wisconsin counties in a collaboration between the CPR Research Group at the University of Arizona's Sarver Heart Center and the Mercy Health System in Wisconsin.
"We think one of the reasons that CPR as directed by international guidelines has not worked well is because it is designed for two entirely different conditions: cardiac arrest and respiratory arrest," said Dr. Ewy. "What is good for one may not be good for the other. Cardiocerebral Resuscitation is designed for cardiac arrest. Sudden unexpected collapse in an adult is almost always due to cardiac arrest. The new approach is not recommended for respiratory arrest, a much less common situation following, for example, drowning or drug overdose."
As a cause of death, out-of-hospital cardiac arrest is second only to all cancer deaths combined, taking the lives of 490,000 Americans every year. Unlike the impression created by TV shows such as "E.R.", the chance of surviving an out-of-hospital cardiac arrest is usually much less than 10 percent. In spite of periodic updates of standardized international guidelines, survival rates have remained more or less unchanged over the last couple of decades. Survival rates are better only if an automated external defibrillator (AED) is available and is used soon after the cardiac arrest.
Michael J. Kellum, MD, Kevin W. Kennedy, MS, and Gordon A. Ewy, MD. Cardiocerebral Resuscitation Improves Survival of Patients with Out-of-Hospital Cardiac Arrest. The American Journal of Medicine (2006) 119, 335-340.