Automated external defibrillators (AED)

Defibrillators Have Taken On A New Life Outside The Operating Room


You know what comes next. It’s one of the most dramatic clichs in hospital dramas: Doctors using a defibrillator administer an electric shock to a patient suffering sudden cardiac arrest (SCA).

Until recently, the only place to receive that life-saving shock was on an operating table or in an ambulance. But thanks to an advanced technology, and to the efforts of the Red Cross, defibrillators have taken on a new life outside the operating room, as automated external defibrillators (AED).

Now a new study in the New England Journal of Medicine (NEJM) shows that these lightweight, portable AEDs may double survival rates.

Researchers trained more than 19,000 volunteers in CPR techniques. Half of the volunteers were also trained to use AEDs, and 1,600 units were supplied to 933 locations. The results: Nearly 110 patients received CPR only, and in that group 15 survived. Meanwhile, 30 patients survived among 128 patients who received CPR and defibrillation from an AED.

In the e-Alert “Shock to the System” (10/1/03), I told you how sudden cardiac arrest occurs when the ventricles of the heart begin to contract chaotically and fall out of synch with their normal rhythm. Blood flow to the body is halted and within five seconds the victim loses consciousness. Because the chance of survival decreases quickly for each minute that treatment is delayed, only about five percent of SCA victims survive.

But if CPR and defibrillation are administered quickly following the onset of attack, chances for survival rise dramatically. In the NEJM study, the rate of survival among the CPR/AED patients was 23 percent.

The American Heart Association has now included AED use in what is called the “chain of survival” for cardiac arrest. The four links in the AHA chain:

* Call 911
* Begin CPR
* Restore heart rhythm with defibrillator
* Get advanced care from medical professionals

The lead researcher of the NEJM study estimates that a national program to place AEDs in health clubs, malls, sporting venues and other places where crowds gather could prevent as many as 4,000 SCA deaths per year in the U.S. But even though AEDs are fairly simple to operate, they’re even more effective when operated by good Samaritans who have been trained to use them. You can help promote AED training by talking to your employer about the Red Cross Workplace Training program.


“Public-Access Defibrillation and Survival After Out-Of-Hospital Cardiac Arrest” New England Journal of Medicine” Vol. 351, No. 7, 8/12/04,
“Defibrillators can Double Survival Rates” Reuters, 8/12/04,