Swift switch from CPR to AED may save lives

April 22, 2002

DALLAS, April 23 - A speedier "hands-off" transition from chest compressions to shocking with an automated external defibrillator (AED) may mean more people survive cardiac arrest, according to a report in today's rapid access Circulation: Journal of the American Heart Association.

The time it takes for an AED to analyze a cardiac arrest victim's electrocardiogram, charge and deliver a shock is called the "hands-off" interval because cardiopulmonary resuscitation (CPR) chest compressions must stop then. Researchers found indications that the shorter the time between stopping chest compressions and when a shock is delivered, the better a person's chance of surviving ventricular fibrillation. Ventricular fibrillation is the chaotic heart rhythm that causes cardiac arrest and sudden cardiac death.

According to the American Heart Association, about 250,000 people a year die of coronary heart disease without being hospitalized. That's about half of all deaths from coronary heart disease - more than 680 Americans each day. Most of these are sudden deaths caused by cardiac arrest. "Our study suggests that not only do you need to act quickly to get an AED on the scene of a cardiac arrest, but you also should move as quickly as possible from CPR to defibrillation," says study author Trygve Eftestol, Dr. Ing., an associate professor at Stavanger University College, Stavanger, Norway.

To determine the link between the hands-off interval and survival, researchers studied 634 hands-off intervals in 156 patients with ventricular fibrillation in which AEDs were used for resuscitation attempts. The duration of hands-off intervals varied by a median of 20 seconds.

Researchers grouped cardiac arrest victims according to their initial probability (high, medium or low) of return of spontaneous circulation (ROSC), which was estimated from the starting point of the ECG readings of their hands-off intervals.

These ECG readings show a person's cardiac activity from the beginning of the hands-off interval - when chest compressions are stopped - until delivery of a shock. During this interval, the AED analyzes the heart rhythm and determines if a shock is needed, charges to the proper shock dose, and prompts the rescuer to deliver a shock. The probability of successful defibrillation with return to spontaneous circulation was also estimated at 5, 10, 15 and 20 seconds into each of the hands-off intervals.

Researchers compared the calculated probabilities with the actual rates of ROSC for the medium-level and high-level groups. From this comparison they found that the shorter the hands-off interval, the greater the chance of a cardiac arrest victim regaining spontaneous circulation. People with the highest initial chance of ROSC would have received the most benefit from a shorter hands-off interval--if they had received a shock immediately, they might have had a ROSC rate as high as 50 percent, says Eftestol. Within five seconds, their estimated ROSC rate dropped to 25 percent; after 15 seconds to 15 percent; and after 20 seconds, it was 8 percent. For those with a medium initial probability of ROSC, shock delivery after a five-second hands-off period resulted in ROSC in 24 percent; after 15 seconds, 17 percent; and at 20 seconds it was 11 percent.

Finally, the group with the lowest probability of ROSC had only about a 5 percent estimated chance of ROSC throughout the intervals. "This study is extremely important for several reasons," says Mary-Fran Hazinski, R.N., M.S.N., former chair of the American Heart Association's emergency cardiovascular care committee. "First, it reaffirms the importance of CPR training and the important role of CPR with the use of AEDs. Second, it provides very solid data that supports the need to shorten the time required for AED rhythm analysis and charging. AED manufacturers are already working to shorten this hands-off interval. Finally, it emphasizes the need for CPR-AED rescuers to practice their skills to ensure the most efficient time to shock delivery - seconds saved can mean improved survival."
-end-
Co-authors include Kjetil Sunde, M.D., Ph.D., and Petter Andreas Steen, M.D., Ph.D.

CONTACT: For journal copies only,
please call: (214) 706-1396
For other information, call:
Carole Bullock: (214) 706-1279
Maggie Francis: (214) 706-1397

American Heart Association

Related Cardiac Arrest Articles from Brightsurf:

Outcomes for out-of-hospital cardiac arrest during COVID-19 pandemic
This study used a large US registry of out-of-hospital cardiac arrests to asses the association between the COVID-19 pandemic and the outcomes of out-of-hospital cardiac arrests, including in areas with low and moderate COVID-19 disease.

Cardiac arrest is common in critically ill patients with COVID-19
Cardiac arrest is common in critically ill patients with covid-19 and is associated with poor survival, particularly among patients aged 80 or older, finds a study published by The BMJ today.

In-hospital cardiac arrest in COVID-19
Outcomes of in-hospital cardiac arrest among patients with COVID-19 are examined in this case series.

New risk tool developed for cardiac arrest patients
Experts have developed a risk score to predict cardiac arrest patient outcomes.

Intravenous sodium nitrite ineffective for out-of-hospital cardiac arrest
Among patients who had an out-of-hospital cardiac arrest, intravenous sodium nitrite given by paramedics during resuscitation did not significantly improve their chances of being admitted to or discharged from the hospital alive, according to research presented at the American College of Cardiology's Annual Scientific Session Together with World Congress of Cardiology (ACC.20/WCC).

Getting to the heart of epinephrine use in pediatric cardiac arrest patients
The effectiveness of epinephrine treatment during resuscitation of adult patients with cardiac arrest is generally promising, but little is known about its effects in pediatric patients.

Bystanders can help more cardiac arrest victims survive
Only 8% of Americans survive cardiac arrest outside a hospital, but that percentage could increase significantly if bystanders recognize cardiac arrest and perform simple lifesaving tasks, a UVA Health physician says in a New England Journal of Medicine article.

Opioid-related cardiac arrest patients differ from other cardiac arrests
People who suffer cardiac arrest due to an opioid overdose are younger, have fewer chronic medical conditions and may be more likely to be to receive bystander CPR, according to a review of emergency response records in Maine.

Selective coronary angiography following cardiac arrest
In the current issue of Cardiovascular Innovations and Applications volume 4, issue 2, pp.

Sudden cardiac arrest in athletes: Prevention and management
It's marathon season, and every so often a news report will focus on an athlete who has collapsed from sudden cardiac arrest.

Read More: Cardiac Arrest News and Cardiac Arrest Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.