Aug. 11, 2004 -- You could save the life of a cardiac arrest victim -- if an AED were nearby.
Every year, 350,000 to 450,000 Americans -- many with no obvious sign of heart disease -- have a sudden cardiac arrest. In cardiac arrests that occur outside of the hospital, as few as two out of 100 survive. AEDs -- automated external defibrillators -- could save many of these lives. The device gives a lifesaving electric shock to the chest of a person who has collapsed from cardiac arrest. Without the shock, nearly all such people would die.
AEDs are automated -- to the point of giving verbal instructions a sixth-grader could understand -- but they still need human help. Somebody has to see the victim collapse. That person has to understand that the victim needs help. And that person has to grab an AED -- fast. Every minute that passes cuts the victim's chance of survival by 10%.
Can real people use AEDs in a real emergency? Yes, if they are trained to use the devices, a real-world study shows. The huge Public Access Defibrillation study involved more than 19,000 volunteers from 993 community sites in the U.S. and Canada.
"We envisioned this trial as bridge, as a first practical step in addressing whether lay people could use these devices safely and effectively to save lives," study leader Joseph P. Ornato, MD, tells WebMD. "What we did was to find a large number of public locations where we identified lay potential rescuers who were not public safety personnel. They were merchants, senior citizens, doormen, and employees who work in hotels. We really wanted to test the concept, using a control group, randomly assigned, to find out whether adding AED to a lay first responder team could lead to more survivors of cardiac arrest." Ornato leads the department of emergency medicine at Virginia Commonwealth University Health System in Richmond.
AEDs Double Rescue Rate
The average-guy and average-gal rescuers all were trained to spot a cardiac arrest victim, call 911, and give CPR. Half of them were also trained to use an AED, and an AED was placed in their public building. The devices came from three manufacturers: Cardiac Science Survivalink, Medtronic, and Philips. Medtronic and Philips are WebMD sponsors.
Three years later, there had been 135 cardiac arrests in the 993 locations. In places where the volunteers did not have AEDs, 15 of 107 people survived. In the places where volunteers did have AEDs, 30 of 128 people survived.
"If you look at just cardiac arrests, the buildings with the AED teams yielded twice the number of survivors," Ornato says. "The flip side was safety. We found these AEDs in the hands of lay people to be extraordinarily safe. We did not have one single instance where a person who needed a shock was not shocked. And we did not have one single instance of a person not needing a shock getting one."
Ornato and colleagues report their findings in the Aug. 12 issue of The New England Journal of Medicine.
Where's the AED?
Of course, all of these lay hands had been trained in the use of AEDs. And they were in public buildings, not in homes, where eight out of 10 sudden cardiac arrests happen. Indeed, only two of the victims in the study were saved in residential buildings, and one of them was saved without an AED.
"The critical issue is that most of these events occur in the home," Ornato admits. "If you look at the number of lives saved if we put these devices in all appropriate public buildings, we would only save 2,000 to 4,000 additional lives. That is humbling. What really drives the public health issue is that these events occur in the home. It is important we have on the table studies showing that lay people can use these devices safely and effectively."
An FDA advisory panel -- of which Ornato was a member -- recently recommended that the Philips AED be approved for sale without a prescription.
That's a big leap of faith, says David J. Callans, MD, professor of medicine and director of the electrophysiology lab at the University of Pennsylvania. There's not yet evidence that plunking down about $2,000 -- the cost of the Philips home device -- won't be a waste of money.
Putting AEDs in public places makes sense, Callans says in an NEJM editorial. But homes are a different matter. The odds of actually needing one of the devices are vanishingly small. To make a dent in cardiac deaths, there would have to be a lot of AEDs in a lot of homes. And that's assuming that somebody is home to see the victim collapse, to call 911, to find the AED, and to correctly operate the device.
"In any given household, the risk of a sudden cardiac arrest is small," Callans tells WebMD. "A lot has to go wrong -- and then a lot has to go right for an AED to save a life."
So why get one? The answer may have more to do with emotion than with facts. Callans says his large, 5,000-person church recently debated whether to buy an AED. It's a large congregation, with many elderly members -- many with heart disease, Callans says. But he calculates that it's very unlikely the AED would ever be needed.
So what did he and his church do?
"The church did get one, mainly because we wanted to do whatever we could, rather than accept the logical argument," Callans says. "But we've had it for a year and never used it. And probably we won't use it next year."
Ornato says that it's important to remember that AEDs don't work all by themselves.
"We really want to stress that it is not the AED that saves lives, it is the system, it is the people who know to make the all to 911 and who know CPR," Ornato says. "Not all cases of heart emergencies need defibrillation. The carry-home message here is not that you can forget CPR or forget 911. It's not that you can just get an AED and your problem is solved. We don't believe that at all. We believe that integrating the AED with the community system, with the individual responder, will give the best response."