12 November—This month, a San Diego councilmember hopes to make the installation of automated external defibrillators (AEDs) mandatory in large newly constructed buildings in the county. If the bill succeeds, San Diego will be the first of what could be a cascade of local governments enacting such a law, giving a substantial boost to the market for AEDs in the United States.
”Right now a lot of cities are watching to see how we do,” says the San Diego councilman, James Madaffer. The bill would require AEDs to be placed in high-occupancy buildings so that a victim of sudden cardiac arrest—which kills more than 250 000 people in the United States each year—would be within three minutes of a defibrillator. In essence, that means placing an AED within 90 meters of any spot in a building. The regulation would expand on San Diego’s existing program to place AEDs widely in public places, including schools, airports, and many businesses. ”From what I’ve heard, we’re the first city to take such a bold step,” Madaffer says. The fate of the proposed legislation could serve as a bellwether for how other local government efforts to expand AED programs might fare.
Some workplaces and public spaces have been proactive in acquiring AEDs, but many others have not, says Al Ford, vice president of defibrillation sales for North America for Cardiac Science Corp., a medical device company that sells San Diego its defibrillators. ”What really drives many markets in this industry is the passing of legislation,” Ford says.
In 2001, Madaffer launched San Diego Project Heart Beat, an initiative that has purchased and distributed more than 4000 defibrillators in the past seven years at a price of about US $2000 each. The effort is considered one of the more successful defibrillator programs in the country, according to rankings from the University of Pittsburgh’s National Center for Early Defibrillation. Evidence from clinical studies suggests that, on average, AEDs save at least one person a day in the United States and Canada. In San Diego County, the AEDs have rescued 52 people since the program began, according to a Project Heart Beat spokesperson.
The latest endeavor is to tackle the challenge of reaching patients in high-rise buildings, who are among the hardest for trained emergency responders to reach in urban areas. As a broad rule of thumb, a victim’s chance of survival decreases by about 10 percent with every minute following cardiac arrest until some intervention begins. A University of Toronto study in 2005 found that paramedic response times tend to be noticeably slower when a victim is located on or above the third floor of a building, where confusing layouts and slow elevators can waste vital minutes. Under the San Diego bill, new construction rated for occupancy by at least 200 people, including residential buildings, would now be required to stock defibrillators and have trained lay responders among its occupants.
Public-access defibrillator programs in the United States first started to spread between 1997 and 2001, when all 50 states passed laws covering some aspect of the use of defibrillators by members of the public. In 2000, the Cardiac Arrest Survival Act became federal law, which freed lay rescuers from being held liable for unintentionally causing injury by using an AED and prompted government buildings to begin installing defibrillators on their premises.
Since then, local laws have either required or encouraged AEDs to be installed in sports clubs and schools, among other places. In 2008 alone, seven states enacted laws supporting the broader availability of AEDs. But the success of those programs nationwide has been spotty. A study published this September in the Journal of the American Medical Association found that the levels of emergency preparedness in different cities led to drastically varied survival rates. The Seattle area, which is known for its broad emergency public-education program, routinely clocks the highest survival rates for cardiac arrest cases, with a 40 percent chance of living for patients in ventricular fibrillation, which is the most common form of cardiac arrest treatable with a defibrillator. Counties in Alabama, by contrast, registered a survival rate below 8 percent. (San Diego was not included in the JAMA study.)
Using a defibrillator has become so highly automated that virtually no training is needed to use one, which is the reason why some districts have pushed to get them widely disseminated. The AED performs all of the diagnostic work and decides when and whether to administer a shock. When a heart enters ventricular fibrillation, the synchronized electric signals that ordinarily keep blood moving rhythmically through the body start to scatter chaotically, causing the heart to quiver rather than pump. The jolt from an AED allows the heart to restart its natural rhythm. The device’s built-in electrocardiograph (EKG) uses a sophisticated algorithm to check for a heartbeat through two electrode pads that a rescuer must attach to the chest. If the EKG identifies the distinctively chaotic waveform of ventricular fibrillation, voice prompts from the AED will advise the rescuer to push a button to deliver a calculated 100-kilowatt shock to the heart, potentially saving a life.