AHA Changes CPR/AED Guidelines

12/28/2006

DALLAS, Dec. 12 ' New American Heart Association resuscitation guidelines may improve survival after out-of-hospital cardiac arrest, according to a study reported in Circulation: Journal of the American Heart Association.

Cardiac arrest is a dangerous, acute event in which the heart rhythm often suddenly becomes erratic, rendering the heart unable to effectively pump blood. Victims quickly collapse and die unless they're resuscitated within a few minutes.

'Generally, when you try to resuscitate a person who is in cardiac arrest, you follow a standard approach that includes activating 9-1-1,' said Thomas Rea, M.D., M.P.H., lead author of the study and associate professor of medicine at Harborview Medical Center at the University of Washington in Seattle. 'Traditional guidelines (2000 guidelines) also call for doing some CPR (chest compressions and ventilations) but emphasized giving shocks from a defibrillator.'

The 2005 American Heart Association Guidelines for CPR and Emergency Cardiovascular Care (ECC) were published in December 2005 and place more emphasis on CPR. Accumulating scientific evidence suggests the importance of high-quality CPR, particularly chest compressions, with minimal interruptions, said Rea, who is also program medical director for King County Medic One in King County, Washington.

'The new way of thinking is that we should administer shocks only at key times in order to provide more CPR during the resuscitation,' he said. 'The idea is that the CPR prepares the heart to better accept the shock and have the shock work.'

The new guidelines call for a single shock from a defibrillator followed immediately by two minutes of CPR, beginning with chest compressions compared to the old guidelines which called for repeated shocks and a pulse check before starting CPR.

To test whether the new approach improves survival compared to the traditional protocol, Rea and colleagues trained King County emergency medical technicians (EMTs) to provide the new protocol and re-programmed defibrillators to support the new guidelines.

'Beginning Jan. 1, 2005, with the hard work and efforts of the EMTs of King County, we implemented the new protocol,' Rea said. 'We compared survival for the year after implementing the new approach to the three years prior, when we used the association's previous resuscitation guidelines.'

The researchers defined survival as surviving at least through hospital discharge. They found that from 2002 through 2004 survival rate after cardiac arrest averaged 33 percent when patients were resuscitated out of the hospital using 2000 guidelines. Survival improved to an average 46 percent for the group that received resuscitation with the new 2005 protocol.

To determine whether EMTs were able to focus more on CPR, Rea and colleagues looked at how quickly EMTs started providing CPR after a shock with the previous versus the new recommendations. They found that the median interval between the first shock and the onset of CPR was 28 seconds under the 2000 protocol. With the change in the protocol, that duration decreased to 7 seconds.

The findings suggest that emergency medical management teams around the United States should consider changing to the 2005 American Heart Association Guidelines for CPR and ECC.

'These are not definitive results,' Rea said. 'But certainly our findings are encouraging and would indicate that changing to the new American Heart Association guidelines probably ought to be high priority.'

Co-authors are: Michael Helbock, M.E.C.P.; Stephen Perry M.I.C.P.; Michele Garcia, M.D.; Don Cloyd, M.I.C.P.; Linda Becker, M.A.; and Mickey Eisenberg, M.D., Ph.D.

The study was funded in part by the Laerdal Foundation and the Medic One Foundation.

Editor's Note: Bystander CPR can double or even triple a cardiac arrest victim's chance for survival. Visit americanheart.org/cpr to learn about the American Heart Association's traditional and self-directed training programs.

Statements and conclusions of study authors published in the American Heart Association scientific journals are solely those of the study authors and do not necessarily reflect association policy or position. The American Heart Association makes no representation or warranty as to their accuracy or reliability.

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