AEDs Aplenty: What Does Their Proliferation Mean for EMS?

Sudden cardiac arrest--it's not just an EMS thing anymore. As AEDs have proliferated in public places and become ever-easier to use, minimally trained laypersons have assumed the job of defibrillating many victims of SCA. Now, as the devices make their way into private homes, spouses and children will begin serving as de facto first responders when their loved ones start arresting. By most people's accounts, this is a good thing. But what does it mean for EMS?

A Safety Device

The latest turn on the AED's road to ubiquity was a landmark decision last fall by the U.S. Food and Drug Administration (FDA). Following a July recommendation from its Circulatory Systems Devices Panel, the FDA approved Philips' HeartStart Home Defibrillator for over-the-counter sales without the prescription previously required. Anyone can buy one now, which likely means the home HeartStart will begin penetrating private residences in what could be significant numbers.

Most people will tell you this is great news.

"The majority of people who suffer sudden cardiac arrest have no previously recognized symptoms, and less than 5% survive, largely because a defibrillator doesn't arrive in time," says Wendy Katzman, business director for Philips' HeartStart Home Defibrillator efforts. "Yet when you look at the literature on public-access defibrillation, when you can defibrillate quickly, the survival rate goes up."

Time is the most significant factor in treating SCA, which claims an estimated 340,000 Americans a year. And AEDs are an effective answer for ventricular fibrillation (VF), the most common type of SCA. If a shock is delivered within the first five minutes following an arrest, the victim's chances of survival are roughly 50-50. With each additional minute that passes, those odds decrease by 10%. After nine minutes--not an uncommon time frame for the arrival of EMS in some locales--there's just a 10% likelihood of living.

This is why, as Katzman notes, public-access defibrillation programs work: Having the devices available immediately, rather than waiting even a few minutes for EMS to arrive, reduces the victim's time to shock, thus increasing their odds of survival.

Scientific literature indicates fairly strongly that PAD programs decrease mortality. Most recently, the results of the well-known Public Access Defibrillation Trial conducted from 2000--2002, featured in the August 2004 New England Journal of Medicine, showed a higher rate of survival to hospital discharge among victims of witnessed public arrests treated with CPR and AEDs than among those treated with CPR alone. In an Italian study from 2002, SCA survival improved from 2.9% when the victim waited for EMS intervention to 11.1% when trained laypersons utilized AEDs instead. Other examples abound, and the wide consensus is that shortening the time to defibrillation through the wide availability of AEDs can only help SCA victims.

"The benefits are enormous," concluded PAD researchers from the Medical College of Wisconsin in a study published in 2002. "Reported VF survival rates can approach 50% or higher...PAD provides the potential opportunity to transform cardiac arrest into a survivable event for most victims by making the community the ultimate coronary care unit."

So, if it works that well in the public environment, how can it not save lives in private homes, where up to 80% of SCAs occur?

"We know that immediate defibrillation saves lives," says Mary Newman, executive director of the National Center for Early Defibrillation at the University of Pittsburgh. "Basically, we consider an AED a safety device, like a smoke alarm, and we believe Americans ought to be able to buy safety devices for their homes."

"It's Not the Box on the Wall..."

Not so fast, say some.

"Data are limited on the number of times a cardiac arrest in the home is witnessed and who is most at risk," the American Heart Association (AHA) warned in a statement following the FDA's decision. "In the absence of scientific evidence of effectiveness, the American Heart Association cannot recommend broad adoption of the home use of AEDs."

"We have no scientific evidence to support the [FDA's] decision,"added Dr. Arthur Kellermann, chair of the Department of Emergency Medicine at Atlanta's Emory School of Medicine, in an Associated Press story on the move, "and I don't think that's a good way to make health policy."

The point being made here is not that home defibrillation won't work, just that there's not yet a strong evidence base to demonstrate that it will.

"The issue the FDA was considering was primarily safety; it wasn't considering effectiveness at this time," says Graham Nichol, MD, chair of the AHA's AED Task Force. "That would be defined by ongoing trials. I would agree that the [HeartStart Home Defibrillator] is safe, and that there's no evidence that a prescription requirement makes it more safe."

Safe is one thing; effective is another. Defibbing a family member or acquaintance, say those on the err-on-the-side-of-caution side of the debate, is different than defibbing a stranger on the street. In the former scenario, emotional factors may fluster the AED user. In their state of emotional duress, the argument goes, even if they're trained, they may not remember how to use the device, or even where they've stored it.

As an example of such difficulties, take the case of 17-year-old Ryan Boslet of Alpharetta, GA. Boslet died following a cardiac arrest at Chattahoochee High School in 2003. When he collapsed following a workout in the school's gym, no one knew how to use the nearby defibrillator that could have saved his life.

The school had recently obtained an AED, but it was a different model than personnel had been trained on. When Boslet collapsed, the staffer trained to use the AED couldn't find its pads (which were stored under a flap in the box).

"It's not the box on the wall that saves a life," AHA spokesperson Robin McCune told reporters after the incident. "Someone has to be trained to know what to do in an emergency and how to use it."

Recent medical literature offers plenty of examples of the difficulties even seemingly easy devices can present in urgent situations. Volunteers have had trouble placing the pads and even opening the packages containing the AEDs. In one study, four of five non-healthcare professionals couldn't use them properly on manikins. Almost two thirds of the time, AEDs in public places aren't even utilized. With an eye on these cases, Philips has created a simplified product that seems hard not to operate properly.

"Imagine it is a loved one [arresting]--it would be a highly stressful situation, and we took that into consideration," says Katzman. "There are features designed to help people in that emergency moment. It has to be highly intuitive, because using it on a loved one is going to be, for most people, a once-in-a-lifetime event."

Intuitive means, for instance, the eye-catching pull handle that initiates voice instructions to guide users through operating the home HeartStart. Verbal prompts lead them through pad placement, and advanced pad technology senses the pace at which the operator is working and adjusts the pace of the instructions accordingly. It also coaches users through CPR, giving cues for breaths and chest compressions and additionally reminding them to call for help from professionals. Further, the home HeartStart self-tests its components daily, sounding an alert when maintenance is required.

As well, simplified AEDs have borne up favorably in at least one trial involving users who weren't healthcare professionals. In a study profiled in the September 2004 issue of Critical Care Medicine, two groups of volunteers--one trained with a brief video and one with no prior training--utilized Philips defibrillators (the home HeartStart and the public-access-oriented HeartStart FR2) to treat patients in a mock cardiac arrest scenario. The video-trained group did better across the board and with the FR2, but there were no adverse events observed with either group, and with the home HeartStart, untrained users did just as well as those who viewed the video.

Training

Those results notwithstanding, training still matters. Even devices as simple as the home HeartStart shouldn't just be popped open and thrown into action by an utter novice. Utilizing them effectively requires familiarity both with their general operation and with the specifics of the model being used.

"We think users should be trained to use these devices before they do," emphasizes Nichol. "That should reduce the chances of becoming flustered."

Training has been a point of emphasis for Philips, which includes an instructional video with the home HeartStart and further encourages users to be schooled in CPR. The company is offering buyers discount coupons for major training organizations like the AHA and the American Red Cross, and its website provides a training locator specific to buyers' regions.

Other Ramifications

There will of course be other ramifications to the FDA's decision. For one, other manufacturers will certainly begin developing AEDs for the home market (ZOLL is already working with the FDA on a product). And, as competition increases, prices should drop, making the devices even more accessible and affordable to even more users. (At $1,995, the home HeartStart is reasonably priced for a defibrillator, but still likely beyond the reach of many.)

Also, although the home HeartStart is not intended for the public environment (businesses, malls, health clubs, etc.), its approval could lead to an increase in AEDs in such places.

"I think it will generate awareness," says Katzman. "One of the most important things we have to do is raise awareness about sudden cardiac arrest and the need for early defibrillation. It's still not something everybody knows about. So we need to continue to raise awareness, and in doing so, more people will make the decision to put them in schools and workplaces, as well as their homes."

Legislative mandates for such placements continue apace. New York recently passed a law requiring AEDs in all of its state buildings; Illinois did the same for its health clubs, school gyms and indoor park facilities. Rhode Island is mandating them in gyms and health clubs, and Louisiana in all physical fitness facilities, including tanning salons.

(Such a requirement might have saved EMS pioneer Jim Page, who died following a cardiac arrest last September at a California spa that didn't have an AED.)

Interest in the home HeartStart is high as well. Between November 2002, when the FDA first approved it for prescription sales, and the decision last fall to remove the prescription requirement, Philips sold more than 6,000 of the devices. The company believes over-the-counter sales could exceed 20,000 a year. The device is already available through such outlets as amazon.com and drugstore.com. The question remains, though: What does all this portend for EMS?

By most accounts, not much. You'll still be called and respond ASAP; you just won't, in some cases, be doing the shocking.

"The role of EMS does not change at all," says Katzman. "When the professionals arrive, they'll take over."

For EMS, there's the take-home point: AEDs in the home can help, but they're not a substitute for the entire chain of survival.

"We want to make sure people don't get the wrong message that just having an AED is going to save everyone's lives," says Ken Bouvier, president of the National Association of Emergency Medical Technicians (NAEMT). "They still need to activate EMS immediately, because the AED alone will only be a quick fix. That person is still going to need transport to the hospital and paramedic services like drug and oxygen therapy. The AED is only a small portion of the chain of survival. Activating 9-1-1 is important, as is bystander CPR and early defibrillation, followed by EMS care and transport."

Given the importance of training in the home-defib equation, there could actually be opportunities for increased EMS involvement in teaching buyers how to perform CPR and use their home AEDs.

"EMS would potentially participate in training and retraining," notes Nichol, "and they would likely participate in some of the quality assurance, which we recommend should continue."

"I'm sure that EMTs and paramedics are going to be called upon to teach more citizen CPR and AED programs," says Bouvier. "Somebody's going to have to teach those courses. We need to make sure that people don't think they can just buy an AED, have it there and when something happens, just stick it on and shock 'em. They're definitely going to have to take a CPR class and an AED class."

For more on the HeartStart Home Defibrillator, see www.heartstarthome.com, or call 866/333-4246.