By Denise Grady
October 26, 2000 - Many people who suffer cardiac arrest and would otherwise die can be saved if ordinary people are trained to use defibrillators to shock them back to life, researchers are reporting today.
In two studies, one conducted at casinos and the other on airliners, survival rates were 53 percent and 40 percent for people who had cardiac arrest and who were treated almost immediately with portable defibrillators, a smaller version of the electrical paddles used in emergency rooms.
Those survival rates are far greater than overall rates in the United States, which are dismally low, 2 percent to 5 percent, because most victims are not defibrillated fast enough. About 225,000 Americans a year suffer cardiac arrest.
Ideally, the shock to the chest should be given within three minutes of the victim’s collapse and is unlikely to work after ten minutes. Each minute of delay drops the odds of survival by 7 percent to 10 percent. Defibrillation is the only effective treatment of ventricular fibrillation.
The two new studies, which appear in the New England Journal of Medicine, reflect a larger trend in the United States to train lay people to use portable defibrillators and make the devices available in large workplaces and public places like sports stadiums, train and ferry terminals, airports, amusement parks, health clubs, community and senior citizen centers and shopping malls.
The drugstore chain C.V.S. has begun offering defibrillators on its Web site by prescription for about $3,000, for people at risk of cardiac arrest.
A rule adopted by the Federal Aviation Administration that took effect in September gave airlines three years to train flight attendants and put defibrillators on all planes that can carry at least 30 passengers and one attendant. American Airlines has defibrillators on all its flights, and most other airlines in the nation have begun including them, as have some foreign airlines.
Portable defibrillators weigh four to seven pounds and cost $2,500 to $4,000. Lay people can be taught to use them in five or six hours.
The American Heart Association estimates that if the national survival rate for cardiac arrest victims could be increased to 20 percent, 50,000 lives would be saved.
The people in the studies were treated with a type of portable defibrillator that first monitored the heart and then shocked it only if the machine detected a particular abnormal rhythm, ventricular fibrillation, which accounts for 80 percent of all cases of cardiac arrest. In that condition, the main pumping chamber of the heart quivers instead of beats and loses the ability to pump blood. People in that condition have no heartbeat or breathing but do have some electrical activity in their hearts. In some cases, ventricular fibrillation is brought on by underlying heart disease, and in some cases the cause in unknown. Ventricular fibrillation causes sudden death and is different from the more common type of heart attack, myocardial infarction, in which blockages in coronary arteries choke off blood supply to the heart. People with myocardial infarction would not be helped and instead would be harmed by defibrillation.
Portable defibrillators, sometimes described as "idiot-proof," will not deliver a shock for any condition other than ventricular fibrillation, because shocking a healthy person or someone with another type of heart problem could be dangerous or even fatal. The machine will not fire if a patient’s heart has no electrical activity, because a shock will not restart such a heart.
The machines have recorded voices that talk users through the steps of defibrillation and cardiopulmonary resuscitation. A study last year showed that sixth-grade students could follow the directions and took only 27 seconds longer to do so than emergency medical technicians or paramedics.
The idea of equipping casinos with defibrillators came from Richard Hardman, an author of one study and coordinator of emergency medical services in Clark County, Nev., which includes Las Vegas. Mr. Hardman said that in 1995, his department noticed that the county had a higher rate of cardiac arrests than other areas with similar populations and that more than 60 percent occurred in hotel casinos.
Dr. Terence Valenzuela, one of authors and a professor of emergency medicine at the University of Arizona, said: "I don’t think there’s anything dangerous to your health about casinos. There are just a lot of high-risk people there. They’re older; there are a lot of smokers; and they congregate there for long periods of time."
Hoping to improve survival, Mr. Hardman and his colleagues approached the casinos about defibrillators. Initially, he said, they resisted, mistakenly fearing that people could be harmed by defibrillators and that the casinos would be liable.
"But defibrillators are applied to somebody who’s essentially dead, with no pulse and no breathing," Mr. Hardman said. "You really can’t make that condition any worse."
Once that was understood, the casinos agreed to have their security guards trained. The first to try it was Boyd Properties, which owns the Stardust, the El Dorado, the California and other casinos in Las Vegas and elsewhere.
The officers, already certified in CPR, then had five to six hours of training to use defibrillators, which were brought into the casinos in March 1997.
The first person saved, on July 1, 1997, was a man in his 70’s who collapsed at a slot machine in a Boyd casino. He was staying at a hotel that didn’t have a defibrillator.
"His wife observed the defibrillator being used and was made aware that if it had happened where they were staying, he probably wouldn’t have survived," Mr. Hardman said, adding that the wife moved into the Boyd hotel.
The man recovered; the idea caught on; and more than 70 casinos, most in Nevada, now have defibrillators, Mr. Hardman said. The study included 105 people who collapsed and were defibrillated between March 1997 and October 1999; 56 recovered. None had brain damage, which can follow cardiac arrest if the heart was not restarted quickly and the brain was deprived of oxygen.
Nevada, New York and at least a dozen other states have passed laws to exempt people from liability when they use a defibrillator to save someone.
A surveillance tape from one of the casinos, provided by Dr. Valenzuela, shows a man collapsing at a roulette table. Guards rush to him, remove his shirt and frantically shave his chest, while nearby casino patrons gamble on, barely looking away from their cards or dice. The guards slap two large adhesive patches, containing the defibrillator’s electrodes, onto the man’s chest. Within seconds, the defibrillator commands them to deliver a shock. They move clear of him to avoid being shocked, one presses a button, and the man’s body jerks as the defibrillator fires. The victim’s heart rate and breathing are restored, and within minutes he is sitting up and talking. An ambulance team wheels him out on a stretcher, past other gamblers, most still oblivious of the man who has essentially died and been revived in their midst.
The second study, by researchers at the University of Texas Southwestern Medical Center at Dallas, examined the use of defibrillators by American Airlines, which began putting them on planes in March 1997. The airline now includes them on all flights and has trained its 24,000 flight attendants to use them.
Six of fifteen passengers who needed shocks between June 1997 and July 1999 survived.
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