Bettering Cardiac Arrest Survival

CPR and defibrillator duration increases survival for heart patients

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) CPR has come a long way since its invention in 1960. It has saved countless lives and become a tool that even those without medical training can use to save loved ones.

However, timing is still everything. A new study published in Circulation: Journal of the American Heart Association reveals that a shorter pause in CPR before defibrillator use significantly increases the survival rate of cardiac arrest victims.

"In an emergency, continue CPR until the EMS arrives."

Researchers learned that patients are significantly less likely to survive until hospital discharge if rescuers paused CPR for more than 20 seconds before delivering a shock with the defibrillator. Patients also were less likely to survive if rescuers paused CPR before and after defibrillation for 40 seconds or more, compared to patients with a pre-shock pause of less than 10 seconds and a peri-shock pause of less than 20 seconds.

Dr. Sheldon Cheskes, M.D., principal investigator of the study and assistant professor of emergency medicine at the University of Toronto said that if the interval between ending CPR and delivering a shock was over 20 seconds, the chance of a patient surviving was 53 percent less than if that interval was less than 10 seconds.

Dr. Cheskes said there was no significant link between the time from delivering a shock to restarting CPR, known as the post-shock pause, leading researchers to believe that the driver for survival is related to the pre-shock pause interval.

The team also discovered that patients with peri-shock pauses of more than 40 seconds had a 45 percent decrease in survival when compared to those who had peri-shock pauses of less than 20 seconds.

American Heart Association resuscitation guidelines advise minimizing interruptions to chest compressions to 10 seconds or less. But previous studies never examined how pauses in CPR affect survival to hospital discharge.

U.S. emergency medical services treat nearly 300,000 cardiac arrest cases a year that occur outside the hospital. Less than 8 percent survive.

Research data was gathered by the Resuscitation Outcomes Consortium, a group of 11 U.S. and Canadian emergency medical services that carry out research studies related to cardiac arrest resuscitation and life-threatening traumatic injury. The study looked at 815 patients between December 2005 and June 2007.

Reviewed by: 
Review Date: 
June 20, 2011
Last Updated:
June 21, 2011