Featured Research

from universities, journals, and other organizations

Shorter pause in CPR before defibrillator use improves cardiac arrest survival

Date:
June 20, 2011
Source:
American Heart Association
Summary:
A shorter pause in CPR just before a defibrillator delivered an electric shock to a cardiac arrest victim's heart significantly increased survival, according to a new study.

A shorter pause in CPR just before a defibrillator delivered an electric shock to a cardiac arrest victim's heart significantly increased survival, according to a study in Circulation: Journal of the American Heart Association.

Related Articles


Researchers found the odds of surviving until hospital discharge were significantly lower for patients whose rescuers paused CPR for 20 seconds or more before delivering a shock (the pre-shock pause), and for patients whose rescuers paused CPR before and after defibrillation (the peri-shock pause) 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.

"We found 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," said Sheldon Cheskes, M.D., principal investigator of the study and assistant professor of emergency medicine at the University of Toronto. "Interestingly there was no significant association between the time from delivering a shock to restarting CPR, known as the post-shock pause, and survival to discharge. This led us to believe that a primary driver for survival was related to the pre-shock pause interval."

The team also found 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.

Based on previous studies, American Heart Association resuscitation guidelines advise minimizing interruptions to chest compressions to 10 seconds or less. However, previous studies didn't measure how such pauses in CPR affected survival to hospital discharge.

According to this study, emergency medical services (EMS) in the United States treat nearly 300,000 cardiac arrest cases a year that occur outside the hospital. Less than 8 percent survive.

Cheskes and colleagues used data gathered by the Resuscitation Outcomes Consortium (ROC), 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.

Between Dec. 1, 2005, and June 30, 2007, 815 patients suffered a cardiac arrest and were included in the study. They were treated by EMS paramedics in Toronto and Ottawa, Ontario; Vancouver, B.C.; Seattle/King County, Wash. and Pittsburgh, Pa. The patients were treated with either an automated external defibrillator (AED) or a manual defibrillator.

Other findings from the study:

  • The length of the post-shock pause showed no significant survival difference between the two groups.
  • AEDs were used to treat 40 percent of the cardiac arrests; 20 percent received shocks from a manual defibrillator.
  • Patients treated with AEDs had pre-shock pause times nearly double those treated in the manual mode, a median of 18 seconds versus 10 seconds. This likely resulted from the time required for an AED to analyze the patient's rhythm as well as the time required to charge it prior to delivering a shock.

The study findings could prompt EMS providers and defibrillator manufacturers to adopt changes likely to increase the number of successful cardiac arrest resuscitations, researchers said. These include:

  • Paramedics should minimize all CPR interruptions; preferably defibrillate patients in manual mode to limit the pre-shock pause to an "optimal time" of five seconds.
  • Manufacturers should modify defibrillator software to quicken the assessment of a patient's heart rhythm, and allow devices to deliver more timely shocks while in AED mode. "If these changes occur, I think you have at least the potential to see a greater number of patients surviving cardiac arrest," Cheskes said.

Although the study was not a randomized controlled trial, researchers said their findings confirm those of other smaller observational studies and that it would be very difficult to perform a randomized controlled trial given the evidence to date. Furthermore, higher rates of bystander witnessed cardiac arrest and bystander-provided CPR occurred in the study group which may have resulted in a selection bias. Although the study controlled for a large number of resuscitation variables, the potential for other components of CPR such as compression rate and depth may have also confounded the findings.


Story Source:

The above story is based on materials provided by American Heart Association. Note: Materials may be edited for content and length.


Journal Reference:

  1. Sheldon Cheskes, Robert H. Schmicker, Jim Christenson, David D. Salcido, Tom Rea, Judy Powell, Dana P. Edelson, Rebecca Sell, Susanne May, James J. Menegazzi, Lois Van Ottingham, Michele Olsufka, Sarah Pennington, Jacob Simonini, Robert A. Berg, Ian Stiell, Ahamed Idris, Blair Bigham, Laurie Morrison on behalf of the Resuscitation Outcomes Consortium (ROC) Investigators. Perishock Pause: An Independent Predictor of Survival From Out-of-Hospital Shockable Cardiac Arrest. Circulation, Jun 2011 DOI: 10.1161/CIRCULATIONAHA.110.010736

Cite This Page:

American Heart Association. "Shorter pause in CPR before defibrillator use improves cardiac arrest survival." ScienceDaily. ScienceDaily, 20 June 2011. <www.sciencedaily.com/releases/2011/06/110620161152.htm>.
American Heart Association. (2011, June 20). Shorter pause in CPR before defibrillator use improves cardiac arrest survival. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2011/06/110620161152.htm
American Heart Association. "Shorter pause in CPR before defibrillator use improves cardiac arrest survival." ScienceDaily. www.sciencedaily.com/releases/2011/06/110620161152.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) — The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Newsy (Nov. 25, 2014) — Need another reason to eat yogurt every day? Researchers now say it could reduce a person's risk of developing type 2 diabetes. Video provided by Newsy
Powered by NewsLook.com
Madagascar Working to Contain Plague Outbreak

Madagascar Working to Contain Plague Outbreak

AFP (Nov. 24, 2014) — Madagascar said Monday it is trying to contain an outbreak of plague -- similar to the Black Death that swept Medieval Europe -- that has killed 40 people and is spreading to the capital Antananarivo. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) — A new study links greater authority with increased depressive symptoms among women in the workplace. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins