The Real Story Behind AED Failures

Today’s AEDs are more reliable than ever, and recalls have declined.

• By Jerry Laws
• Nov 01, 2011

Fifteen years of reports to an FDA database included 1,150 failed attempts to defibrillate people in cardiac arrest. The raw number announced Aug. 30 with the online publication of a study analyzing the failures was alarming, to be sure. The larger picture of automated external defibrillator reliability and safety is more reassuring, however.

"AEDs are very effective. Unfortunately, when some of these reports come out, there begins to be a lot of focus on the 'safety' of AEDs," said Cam Pollock, vice president of global marketing for Physio-Control. "And the thing to remind people of here is that an AED failure is not a safety issue; people are not hurt by an AED's failure. Someone on whom an AED is being used is in cardiac arrest. The heart hdas stopped, they only have a few minutes to live. Having an AED available is really their only chance."

Reliability rates for Physio-Control's AEDs have improved every year for the past 10 to 12 years, he said. The Annals of Emergency Medicine study showed the number of AED failures increased from January 1993 to October 2008 -- the total for the entire period was 1,150 failed attempts to defibrillate -- but the number of AEDs deployed during that period increased much faster. Thus, the number of adverse events per AED went down.

"Our own reliability rates have gone up every single year. The AEDs that we are manufacturing and selling today are the most reliable we've ever made," said Pollock. "We've seen our own numbers of adverse events coming down. We've seen our number of field failures coming down. And again, those numbers are small to start with."

In the United States, around 300,000 people die of sudden cardiac arrest every year, and around 13 percent of those deaths occur at work. A victim's chance of surviving drops by about 10 percent with each passing minute.

A total of somewhere between 1 and 2 million AEDs have been distributed, Pollock said, adding that anyone looking at the number of failures also should look at the number of devices that are out there.

"In 99.9 plus percent of the time, AEDs work the way they're intended to work. The bigger issue is that there's literally tens or hundreds of thousands of people who die every year because there's no AED available. For us as a company, that's where we think the focus should be. If the device is out there working 99.9 percent plus of the time, you’re better off having an AED when you need it than not."

He said the Annals study ("Analysis of Automated External Defibrillator Device Failures Reported to the Food and Drug Administration," by Lawrence A. DeLuca Jr., M.D., EdD, and colleagues from the Arizona Emergency Medicine Research Center at the University of Arizona Department of Emergency Medicine) contains two messages for safety managers:

1. The benefits of AEDs far outweigh the risks, and having an AED program is an important way to prevent deaths from sudden cardiac arrest.

2. "AEDs have a certain amount of attention that they need. It's incumbent on people who are getting these programs in to take that approach to it. It's not something you can buy and stick in a closet somewhere and expect to get any kind of results," Pollock said.

Program Management and AED Maintenance
He said an employer's AED program as a whole has to work well. This means when a company buys an AED, management needs to ensure workers are aware of it and know how to call 911. The company should provide a good training program covering both AED use and CPR, and because of turnover and occasional changes in CPR guidelines, the employees should be retrained every couple of years, Pollock said.

AEDs perform self-checks at different levels daily, weekly, and monthly, but those self-checks don't do any good if the machine are not being checked by program administrators regularly. At least once per week is recommended. Personnel should check for a wrench or blinking light on the screen, for example, to ensure they become aware of any problem -- low battery, expired electrodes, or whatever it might be.

AED owners should review the maintenance information included in their owners' manuals, Pollock said. Manufacturers' websites are good sources for information, as well, as are sites such as the Sudden Cardiac Arrest Foundation's http://www.sca-aware.org/, he said. Physio-Control offers an implementation and management program named Heart Safe Solutions that helps owners determine the placement of their AEDs, provide the most current training, and meet regulatory requirements. The owners can take advantage of online management programs, automated shipment of AED supplies, a 24/7 hotline, and post-event support after a defibrillator is used during a sudden cardiac arrest incident.

Tomorrow’s AEDs
Pollock said automated external defibrillators are being continually improved. All AEDs are extensively tested during the manufacturing process, before they leave the factory. He acknowledged large recalls have occurred in recent years but said even those involve low failure rates: "You're looking at less than 1 percent of the [AED] population failing but then recalling large populations of the devices," he said.

"We're constantly looking for ways in our future products to improve them from a reliability standpoint and from a performance standpoint, to make them easier to use. One of the key goals for us for the future is to have more online monitoring of the products that are hanging on the wall. So rather than having someone have to go and look at it, you would actually be able to see from a remote location whether the device is OK. That will actually make it even easier to make certain the devices are maintained.

"You never want to hang them on the wall and forget about them.... But as far as worrying about failures and checks, we want to make that as easy as possible for people. If there's a problem with a device, we want to know about it as early as possible. That's what that was all about."

Communities with high survival rates from witnessed ventricular fibrillation (VF) incidents have gone way beyond AEDs, he noted, explaining that metropolitan Seattle and Rochester, Minn., have recognized the importance of early defibrillation and use outreach and training to do as much as possible to ensure bystander CPR is available and effective when it is delivered. Cooling the patients is another practice that raises patients' survival rate, as does having the EMS system measure its own performance to foster continuing improvement.

"A lot of large cities across the country -- cities like Detroit, Chicago, New York City -- are down in the low single digits in their survival rates. The thing that's amazing is that the formula for what you can do to boost survival rates is pretty well known," Pollock said.

Commercial airplanes and airports are equipped with AEDs, and the penetration rates in U.S. schools may be as high as 50 percent, he said. Many health clubs, stadiums, and shopping malls have the devices. But he said their penetration into workplaces is much lower, probably 20 to 30 percent. "There are still plenty of places out there in the United States that could benefit from AEDs that don't have them. We actually believe that the overall market in the United States is still fairly low penetration. Our best estimate is maybe 20 to 25 percent could have an AED," said Pollock.

He said high-profile SCA deaths still drive many adoptions and state mandates. For example, a large power company recently bought thousands of AEDs from the company after an employee died from it, and Ohio enacted a law mandating school AEDs after some student athletes died.

King County EMS Survival Rate Stands Out
Released in September 2011, the 2011 annual report of Seattle & King County's Division of Emergency Medical Services said the county's EMS system achieved a 49 percent cardiac arrest survival rate in 2010, which was the highest survival rate so far for the region. Noting that most survival rates in the United States are around 5 to 10 percent, the report calls the 49 percent rate "an astounding achievement."

"We are fortunate in King County to have one of the most innovative and effective emergency medical services systems anywhere," King County Executive Dow Constantine said Sept. 6. "The response that goes into every 911 call reflects extraordinary expertise and teamwork among fire departments, paramedic providers, dispatch centers, physicians, hospitals, and public health workers."

The county's EMS system responded to 210,719 calls to 911 in 2010, of which 47,012 were for advanced life support. The average medic unit response time held steady at 7.6 minutes. "The success our EMS system has achieved in providing excellent, standardized services countywide is quite remarkable," said Dr. David Fleming, director and health officer for Public Health -- Seattle & King County. "Patient survival from cardiac arrest is one of the most critical measures of success for any EMS system, and survival rates in King County make our system the gold standard."

The county's programs include:

• The Resuscitation Academy, a three-day training program about resuscitation science and the EMS systems in Seattle and King County, attended by EMS managers from around the country.
• CPR and AED training for county residents, including the King County Student CPR/AED program, which trained 17,792 students to perform CPR and use an AED during 2010.

For more information, visit http://www.kingcounty.gov/healthservices/health/ems.aspx.

This article originally appeared in the November 2011 issue of Occupational Health & Safety.