By Joe Fahy
Pittsburgh Post-Gazette
Copyright 2006 P.G. Publishing Co.
Hoping that better chest compressions would lead to improved outcomes for victims of cardiac arrest, researchers in the Pittsburgh area and other communities tested a device on hundreds of patients as a substitute for conventional cardiopulmonary resuscitation.
But two separate studies of the AutoPulse device produced very different results, leaving researchers with questions about its effectiveness, according to findings published today in the Journal of the American Medical Association.
One study in Richmond, Va., found better survival rates for the device compared to manual CPR.
But the other study, which involved patients in suburban Pittsburgh and other communities in the United States and Canada, was halted early because of poor outcomes.
Use of the device was “associated with worse neurological outcomes and a trend toward worse survival” compared to standard CPR, researchers found.
“The results were definitely surprising,” said Dr. Vincent Mosesso, an associate professor at the University of Pittsburgh School of Medicine and the principal investigator in the study locally. He noted that early clinical trials of the device, produced by Zoll Medical Corp., were promising.
The portable device, which has been approved by the U.S. Food and Drug Administration, resembles a small surfboard and is designed to provide consistent, precise, automated chest compressions during CPR. Patients are strapped to it at the chest and the operator pushes a button to begin the automated compressions.
Researchers noted that maintaining consistent compressions through manual CPR can be difficult.
Besides the Pittsburgh area, patients with cardiac arrest were enrolled in one study in Columbus, Ohio, suburban Seattle and communities in or around Calgary and Vancouver. More than 1,000 patients were randomized to receive CPR either manually or using the AutoPulse device.
The study found no significant difference in survival rates four hours after the 911 call. But survival rates to hospital discharge were lower in the AutoPulse group, along with survival rates with good cognitive function.
Stephen Shurgot, executive director of Eastern Area Prehospital Services, which serves Edgewood, Swissvale, Turtle Creek, Wall, Wilkinsburg and Wilmerding, said workers liked the device. But he noted that survival rates were not better.
William Plunkett, chief of Baldwin EMS, reported similar outcomes and said the device was cumbersome to use.
In the other study, researchers compared resuscitation outcomes before and after an EMS system in Richmond, Va., switched from manual CPR to the AutoPulse device. They found that using the device was associated with improved survival to hospital discharge.
In an accompanying editorial, doctors said the varying results could be influenced by details in using the device and suggested that more study is needed.
Ward Hamilton, vice president of marketing at Zoll Medical Systems, said the company was “anxious to get another study going.”
“Obviously, we’re very disappointed in one study not running to completion, but pleased the other study showed good benefit.”