What are your chances of surviving cardiac arrest outside a hospital setting? In a word, remote. But some doctors are turning that around, boosting survival rates to previously unthinkable levels. That's great news, right? Now for the bad news: your likelihood of being in that lucky group of survivors depends a great deal on where you live. "It's like real estate—location, location, location," says Dr. Arthur Sanders, a professor of emergency medicine at the University of Arizona's Sarver Heart Center.
That is the upshot of a study appearing this week in the Journal of the American Medical Association. Dr. Graham Nichol, director of the University of Washington's Center for Prehospital Emergency Care, surveyed the outcomes of cardiac arrest in 10 North American cities and states. Though outcomes for most medical procedures vary with factors like socioeconomic status, the differences in this study were even more pronounced than usual. Survival from site to site varied as much as fivefold. Patients in Seattle who were treated by emergency medical technicians (EMTs) pulled through in 16 percent of cases. In Alabama, they survived just 3 percent of the time.
And Alabamans are probably better off than people in many other states. That's because, like the other localities represented in the JAMA study, Alabama participates in a government-funded research network dedicated to improving outcomes after cardiac arrest. Cities outside that network—even places like New York City, with all its high-powered medical centers—appear to have lower survival rates, judging by studies from the 1990s. "Older studies from New York, Chicago, Detroit and Los Angeles found overall survival rates of just 1-2 percent," says Sanders, who wrote an editorial in JAMA to accompany Nichol's paper.
What's Seattle doing that other cities aren't? The JAMA study didn't analyze public-health policies. But Nichol, who happens to live and work in Seattle, says one crucial difference lies in the simple fact that the city tracks outcomes of cardiac-arrest cases. Most cities do not—and therefore have no basis on which to judge their performance or measure improvements.Second, it has an exceptionally well-organized EMS system. Emergency-medical technicians and paramedics are not only experienced and well trained, but also monitored by physicians on a daily basis to make sure they're doing everything in the best way possible. This daily oversight is not common in other cities, and the organization and efficiency of EMS systems can vary widely. Some are run by hospitals—others, by fire departments. In some towns, they're staffed by volunteers rather than paid professionals.
Finally, the public in Seattle is well informed about what to do in the case of such an emergency, thanks to a public-service campaign from the Seattle Fire Department that focuses on training the public to recognize and respond to cardiac arrest.
Wherever you are, the most crucial factor is rapid treatment. "Survival depends on how quickly you recognize the problem and respond—how quickly you start CPR, how quickly you provide a defibrillator and how quickly you cool the patient to protect the brain," Nichol says. Chances of survival can decrease by as much as 10 percent a minute, so there's no time to waste. Well-organized EMS systems are crucial. So are readily accessible defibrillators and bystanders who will perform CPR.
Even under the best of circumstances, not all patients are equally treatable. Cardiac arrest—or the cessation of the heart's activity—may occur for a variety of reasons. In about 30 percent of cases, the cause is a heart attack. Roughly 25 percent of the time, the culprit is ventricular fibrillation, a type of arrhythmia in which uncoordinated electrical activity in the heart makes the heart muscle tremble rather than contract properly. Other causes include infection, trauma and drug overdose.
The best chances of survival come when cardiac arrest is caused by ventricular fibrillation and someone is there to witness the patient's collapse, so that treatment can be started right away. Thanks to the widespread availability of defibrillators in ambulances, airplanes, airports and even casinos, cardiac arrests in those venues have become more survivable. "Personnel are trained in the use of defibrillators, and they can get to you within five minutes," says Sanders. "In these settings, survival rates for ventricular fibrillation are as high as 45 percent." The machine measures electrical activity in the heart to verify that the problem is ventricular fibrillation. Then, when you push a button, the device delivers an electric shock to get the heart pumping again.
A new treatment protocol developed by Dr. Gordon Ewy, head of the University of Arizona's Sarver Heart Center, also appears to boost survival substantially for ventricular fibrillation, at least where witnesses are present to call for help. Instead of working to restore both heartbeat and breathing, EMTs focus primarily on the heart. "The vast majority of adults in cardiac arrest have a heart problem, not a lung problem," Sanders explains. "Simply getting the blood circulating again by providing uninterrupted chest compressions is the most important treatment." Ewy, Sanders and colleagues published a study in JAMA in March, showing the results when EMTs in two Arizona towns were trained in the new technique. "Before adopting our protocol, 4.7 percent of patients survived," Sanders says. "Afterwards, that increased to 17.6 percent." Another study in the Annals of Internal Medicine this month showed that the same approach more than doubled survival in two Wisconsin counties, from 20 to 47 percent. More importantly, it boosted "neurologically intact" survival from 15 to 39 percent.
It's not only EMS teams who can take advantage of this new approach to resuscitation. For bystanders who happen to witness someone going into cardiac arrest, the equivalent is "hands-only" CPR, where you continuously give the patient chest compressions to pump blood, without taking time to breathe into the patient's mouth. An online demonstration is available at www.heart.arizona.edu/publiced/lifesaver.htm.
Even with the best of techniques, not everyone can ultimately be saved. Nichol's study deliberately excluded 8,622 patients who were not treated because of their own written requests (known as "advance directives"), terminal illnesses or the request of the family. And other cases are hopeless from the start. A second study in JAMA this week laid out new rules for helping to identify the futile cases. These include situations in which all of the following are true: there was no witness to the event (so help was delayed), no bystander attempted to perform CPR, no defibrillator was used and the cardiac arrest occurred before EMS arrived (as opposed to happening in the ambulance). Applying these guidelines can save EMTs countless hours of working on patients who have no chance of making it home alive. By the same token, they can give emergency teams a better sense of when it's worth it to keep trying.
As Nichol says, not long ago, cardiac arrest meant certain death. Now, as he puts it, "cardiac arrest is a treatable condition"—provided you live in the right town.
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