Out-of-hospital cardiac arrest outcomes improve with increased AED use

Perhaps not so shocking, but true: When infrastructure for early response to out-of-hospital cardiac arrest improves, so do outcomes, according to a study published online Nov. 15 in Circulation.

Researchers from The Netherlands reviewed the outcomes of patients reported to have out-of-hospital cardiac arrests over a seven-year span to see if changes in public policy and care saved lives. Marieke T. Blom, PhD, MA, MSc, of the department of cardiology at the University of Amsterdam, and colleagues used data from an ongoing prospective registry through the Amsterdam Resuscitation Study to see trends. They were able to incorporate hospitalization data, as well as information from emergency medical personnel and directly from automated external defibrillators (AEDs).

Between 2006 and 2012, they found rates of survival improved in patients with shockable initial rhythm. Patients with favorable neurological survival after out-of-hospital cardiac arrest increased from 29.1 percent to 41.4 percent between 2006 and 2012.

AED use increased nearly three-fold over the seven-year span (21.4 percent vs. 59.3 percent). The number of AEDs dispatched to the scene tripled (16 percent vs. 48.7 percent) and onsite AED use nearly doubled (5.4 percent vs. 10.6 percent). Bystander assistance rates improved from 65.8 percent in 2006 to 81.2 percent in 2012. Shocks delivered in under six minutes increased exponentially as well, from 9.2 percent in 2006 to 21.7 percent in 2012.

Blom et al noted that some of these observed changes related to improved distribution of AEDs and widespread application of the 30:2 cardiopulmonary resuscitation protocol between 2006 and 2007. They also credited a campaign launched by the Netherlands Heart Foundation called the “Six-Minute Zone” in 2007, “aiming to raise AED awareness in the community and increase the number of resuscitation attempts in which a defibrillation shock was delivered within six minutes after the first call to the national emergency number.”

They added, “The subsequent increased survival rate after hospital admission clearly shows that improving prehospital survival rates after OHCA [out-of-hospital cardiac arrest] is not merely changing the place to die, as some skeptics of layperson defibrillation have suggested.”

For more on this topic, please read Using Logistics to Put AEDs Where They’re Most Needed.