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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