Automated External Defibrillators

Cardiac arrest—the sudden and abrupt loss of heart function—is a leading cause of death in the United States. According to AHA, about 326,200 out-of-hospital cases of sudden cardiac arrests occur annually in the United States; less than 10% of those victims survive. Additionally, about 209,000 patients experience a cardiac arrest during their hospital stay and require CPR, yet less than 25% survive to discharge. (Mozaffarian et al.)

In about 40% of individuals suffering cardiac arrest, the heart goes into an uncontrolled quivering pattern (i.e., fibrillation) that stops it from pumping (AHA "Lay Rescuer"). Because death can occur quickly, AHA recommends that defibrillation for these individuals begin within three to five minutes for out-of-hospital cases of cardiac arrest and within two minutes for cases of in-hospital cardiac arrest in order to jolt the victim's heart with an electric shock and restore a normal heartbeat. For every minute that passes before regular heart rhythm is restored, the patient's survival chances are reduced—by 7% to 10% if no CPR is available and by 3% to 4% if bystander CPR is available. (AHA "Implementing an AED Program"; Morrison et al.)

ECRI Institute recognizes three types of external defibrillators:

ECRI Institute anticipates that hospitals will increasingly use a combination of technologies—manual defibrillators that can be switched to an AED mode in many areas of the hospital where conventional defibrillators are needed, and AEDs in other areas, such as outpatient facilities, where staff may lack rhythm recognition skills or code teams may have difficulty quickly reaching collapsed patients, staff, or visitors.

AHA's combined 2010 and 2015 guidelines on emergency CPR stress the importance of using AEDs as a way to facilitate early defibrillation. AHA states that, in instances of witnessed cardiac arrest in which an AED is immediately available, defibrillation should be administered as soon as possible, as opposed to administering chest compressions first. (AHA "2015 American Heart Association Guidelines")

Studies suggest that delays occur within hospitals in responding to patients' cardiac arrest. In a study of in-hospital cardiac arrests, researchers found that although the median time to defibrillation for patients in cardiac arrest was one minute, 30% of patients in the study did not receive defibrillation within the goal of less than two minutes. (Chan et al. "Delayed") Delayed defibrillation was associated with a...