electrical disturbance disrupts the heart so much that it stops. An AED can shock the heart back into a normal rhythm.
In the new study, whose lead author was Johns Hopkins University medical student Ross Pollack, researchers looked at 49,555 people treated for cardiac arrest by an emergency medical services team between 2011 and 2015. The study analyzed a portion of those patients – the ones whose cardiac arrests happened in public outside of a hospital, were witnessed by bystanders, and were “shockable,” meaning the heart still had enough activity to respond to a defibrillator shock.
Researchers found that 66.5 percent survived with the help of a bystander-administered AED, versus 43 percent who survived after waiting for an emergency medical crew to deliver a shock to their hearts. Similarly, cardiac arrest patients were more likely to return to their normal neurologic levels when assisted by bystanders who used AEDs instead of waiting for emergency technicians.
Dr. Raina Merchant, an emergency medicine doctor and associate professor at the University of Pennsylvania, was pleased to find the study reflected similar benefits and results of AED use, regardless of what part of the country or continent the devices were administered. The report also backs up previous studies showing “the devices can be used by anyone,” she said.
Yet, she said the study also demonstrated that not enough people are using defibrillators. Only about one in five cardiac arrest patients in the study received an AED shock from a bystander. It’s uncertain whether an AED was available in every case included in the study, and researchers did not consider the impact of calling 911 and starting immediate CPR.
“We know that they save lives, we know when they’re used they can make