New research shows that cardiac arrest patients may be more likely to survive and avoid permanent disabilities when bystanders use an automated external defibrillator (AED) to treat them before medical help arrives.
Without a bystander using AED shock therapy, 70 percent of cardiac arrest patients either died or survived with impaired brain function.
An AED is a portable electronic device that automatically diagnoses the life-threatening cardiac arrhythmias and treats them through defibrillation, the application of electricity which allows the heart to re-establish an effective rhythm.
“It’s important to have an AED and to learn how to use it, because you can really improve the chances of a person surviving with excellent neurological ability,” said lead researcher Dr. Myron Weisfeldt.
The longer it takes for a patient to get a lifesaving shock, the worse the outcome, Weisfeldt said. “Every minute that goes by without treatment, you lose about 10 percent of the survival,” he said.
For this study, a team of U.S. and Canadian researchers examined data on 49,555 cardiac arrests that happened outside of hospitals in major cities.
The researchers found that nearly 66 percent of victims on whom a bystander used an AED survived to hospital discharge, compared to 43 percent who did not receive immediate AED intervention.
During a heart attack, blood flow is blocked to some part of the heart, damaging that area of the organ but not stopping it altogether.
An AED automatically assesses the heart’s rhythm and decides if it should be shocked or not. The device reassesses the heart rhythm and if necessary, delivers further shocks.
Weisfeldt and his team, including lead author John Hopkins medical student Ross Pollack, would like to see greater distribution of AEDs, including equipping police with defibrillator, especially in regions where it takes emergency responders long to get to the patient.
A bystander using an AED does exactly what a paramedic or doctor would do. The study was published in Circulation, the journal of the American Heart Association (AHA).