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The newspaper of The Johns Hopkins University December 3, 2007 | Vol. 37 No. 13
Lives Saved When Defibrillators Are Placed in Large Public Spaces

Good Samaritan access to 'shock' devices doubles survival from heart attack

By David March
Johns Hopkins Medicine

Heart experts at Johns Hopkins and elsewhere have evidence that at least 522 lives could be saved annually in the United States and Canada by the widespread placement of automated external defibrillators, the paddle-fitted electrical devices used to shock and revive people whose hearts have suddenly stopped beating.

Their findings support broad deployment of battery-powered defibrillators in public spaces where large gatherings occur, such as senior care facilities, hospitals, sports stadiums, community centers, shopping malls, airports and the lobbies of large hotels and office buildings.

The team's study results, presented Nov. 5 at the American Heart Association's annual Scientific Sessions in Orlando, Fla., are among the first conclusions to emerge from a landmark series of studies, known as the Resuscitation Outcomes Consortium, designed to reveal the best life-saving techniques for cardiac emergencies.

Every year, experts say, more than 300,000 Americans of all ages die from sudden cardiac death. A good many of them are seniors.

In the latest work, researchers found that in real life emergency situations, use of the laptop- size devices by random bystanders more than doubled survival rates among victims felled by a sudden heart stoppage due to a heart attack or errant heart rhythm. Each device, which costs on average more than $2,000, is equipped with a digital instruction screen that provides simple step-by-step directions.

"Our results were emphatically clear," said principal investigator Myron "Mike" L. Weisfeldt, the William Osler Professor of Medicine at the Johns Hopkins School of Medicine and past president of the American Heart Association. "Good Samaritans, when given access to automated defibrillators in potentially fatal emergencies, save lives.

"This is a serious matter of public health policy and similar to previous discussions about placing fire extinguishers near building exits, wearing seat belts while driving or manufacturing cars with airbags," Weisfeldt said.

Previous research has shown that time is critical in saving the majority of people from sudden cardiac death. Care must be provided as rapidly as possible, within five minutes of the heart attack, Weisfeldt says, and must employ the physical chest compressions that are part of cardiopulmonary resuscitation and, if needed, a defibrillator.

Currently, Weisfeldt says, automated external defibrillators are used mostly by paramedics and other emergency medical workers who have additional training in CPR. But often, he notes, bystanders first on the scene of an emergency are available to provide life-saving aid before ambulances can arrive.

As part of the study, conducted in 11 major cities in the United States and Canada from December 2005 through November 2006, researchers closely monitored the circumstances surrounding nearly 10,000 incidents of cardiac arrest called in to 911 emergency telephone lines. Pulled from each medical file were details about use of CPR and a defibrillator.

Of the 7 percent of hospitalized patients who survived overall, 149 had received a shock from an automated external defibrillator used by a bystander, and 36 percent of those patients survived. Among the bystanders who rushed to help, 23 percent were nearby police, and 42 percent were health care workers. Locations varied from sports stadiums to indoor lobbies and seniors' housing complexes.

If results from the original study population of 20 million are extrapolated to the general population of the United States and Canada (roughly 360 million), an estimated 522 lives are saved.

"This research is the closest thing to the real-world experience of life-threatening, sudden cardiac death that we have," said Weisfeldt, adding that he plans to educate Maryland state officials on the benefits of increased public access to the equipment. "Government, community and business leaders need to carefully consider increased access to automated external defibrillators when making healthy public policy."

In 2006, the state of Maryland made the devices mandatory on-site equipment for all public sports games.

At The Johns Hopkins Hospital, Weisfeldt notes, the surprise death of a colleague in 2003 propelled hospital staff to place 23 automated external defibrillators in heavily trafficked spaces and corridors. More than 100 of the devices have been placed at the university's Homewood campus.

The study, set to continue through 2010, was funded by the National Heart, Lung and Blood Institute, a member of the National Institutes of Health.


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