Practical Prevention—How Defibrillators in Public Places Can Save Lives
What could be a more worthwhile form of prevention than saving someone's life? Sudden cardiac arrest victims feel fine one minute, then the next minute they are dead. Can computerized gadgets, called AEDs, make it possible to change the outcome? These devices are effective, fairly simple to operate, and now readily available in many public places. The idea is to have them handy for trained members of the public to use immediately on cardiac arrest victims.
Frequency of Sudden Heart Death
In the US, sudden heart death is a growing issue that's even beginning to affect those under the age of 18. The American Heart Association estimates that there are between 1,900 to 14,200 cases of pediatric cardiac arrests (from all causes) occuring outside of hospitals each year.
Researchers blame the trend on an increasing incidence of inactivity, obesity, and other risk factors among our nation's youth. All told, heart disease is still the number one killer in the US today, resulting in nearly one million deaths each year. Nearly half of these deaths occur suddenly and unexpectedly from cardiac arrest.
How Rapid Defibrillation Helps
During cardiac arrest, the heart stops pumping, and there is no effective heartbeat. The most common culprit is an irregular heart rhythm called ventricular fibrillation. The irregular rhythm causes the heart to fibrillate, or quiver uncontrollably, and renders the heart unable to pump blood around the body. This can lead to death in minutes.
According to recent studies, the single greatest factor in surviving cardiac arrest is early defibrillation. If ventricular fibrillation is stopped in one minute or less, survival rates can be as high as 90%. But when defibrillation is delayed, survival plunges to 50% at five minutes, 30% at seven minutes, 10% at 10 minutes, and less than 5% at 12 minutes. Automated external defibrillators have the potential to improve survival rates because they can be readily available outside of a medical setting, and they are relatively easy to operate.
Who Should Use an AED?
Increasingly, nonmedical people are being trained to use defibrillators. The American Heart Association promotes the use of AEDs by police officers, firefighters, security guards, sports marshals, ski patrol members, ferryboat crews, and airline flight attendants. Additional people who may benefit from AED training include family and friends of persons at high risk and even employees at worksites or public places where large numbers of people congregate.
The Centers for Disease Control and Prevention is conducting a study to determine who should be trained in AED use and where the devices should be placed. AEDs are usually put in areas where they will most likely be needed, and where quick service by paramedics is not readily available. Common locations include airports, shopping malls, casinos, community centers, and sports or medical facilities.
With more AEDs around, the key to safe and proper use is training. The American Heart Association and American Red Cross offer AED classes. When used by trained responders, the devices can be extraordinarily effective, with overall survival rates as high as 49%.
How the Devices Work
In addition to being effective, recent advances in technology have made today's AEDs far safer and simpler to use. The lightweight portable devices have self-adhesive electrode pads that usually depict just where to stick them. Voice and text prompts guide the user through the few simple steps. The AED analyzes heart rhythm, automatically charges the machine when appropriate, and tells the user when to push the shock button. It then shocks the heart with a brief burst of electricity.
Since AEDs now are more available and much easier to use, concerns regarding inappropriate use by a non-trained lay person have significantly diminished. Forty-five states now have also passed legislation protecting laypersons from medical litigation when an AED has been used in good faith.
The majority of cardiac arrests occur at home. Patients with heart disease and at risk for cardiac arrest are frequently treated with implantable cardio defibrillators (ICD). Some patients, such as those who have contraindications to ICD implantation, may benefit from having an AED at home. Discuss this with your doctor.
CPR Is Still Important
For years people have been encouraged to learn cardiopulmonary resuscitation, or CPR. Learning to use an AED takes that lifesaving effort one step further. The American Heart Association says the four links in the chain of cardiac arrest survival are:
- Calling 911
- Early CPR
- Early defibrillation
- Early advanced medical care
As part of this coordinated plan, in the future, AEDs could become as common as fire extinguishers.
American Heart Association
American Red Cross
National Heart, Lung, and Blood Institute
BC Health Guide
Heart and Stroke Foundation of Canada
Chen PS, Wolf PD, Ideker RE. Mechanism of cardiac defibrillation: a different point of view. Circulation. 1991;84:913.
Eisenberg MS, Moore J, Cummins RO, et al. Use of the automatic external defibrillator in homes of survivors of out-of-hospital ventricular fibrillation. Am J Cardiol. 1989;63:443-446.
Food and Drug Administration website. Available at: http://www.fda.gov/hearthealth/treatments/medicaldevices/aed.html. Accessed November 13. 2007
Marenco JP, Wang PJ, Link MS, Homoud MK, Estes NA 3rd. Improving survival from sudden cardiac arrest: the role of the automated external defibrillator. JAMA. 2001;285:1193-1200. Review.
McDaniel CM, Berry VA, Haines DE, et al. Automatic external defibrillation of patients after myocardial infarction by family members: practical aspects and psychological impact of training. Pacing Clin Electrophysiol. 1988;11:2029-2034
Out-of-hospital cardiac arrest—statistics: statistical fact sheet—miscellaneous 2007 update. American Heart Association website. Available at: http://www.americanheart.org/downloadable/heart/1168639579314OUTOFHOSP07.pdf. Accessed November 26, 2007.
SoRelle R. States set to pass laws limiting liability for lay users of automated defibrillators. Circulation. 1999;99:2606-2607.
Last reviewed November 2007 by Marcin Chwistek, MD
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