External defibrillators are used in many settings, by people who have different levels of training.
In the clinical setting, external defibrillators are used in emergency rooms, intensive care units (ICU) and throughout the hospital by trained professionals. Training is usually mandatory and refresher training is provided regularly. There are established systems for maintaining and assuring that the devices are ready to be used.
Outside of hospitals, external defibrillators are used by emergency medical personnel and first responders such as police. The frequency and type of training required for first responders is set by employers and by state or local regulations.
Automated External Defibrillators (AEDs) are found in airports, community centers, schools, government buildings, and other public locations. These devices are intended for use by the general public. Public Access to Defibrillation (PAD) programs must have a medical director who oversees the program and a program coordinator who is usually responsible for device maintenance.
AEDs also are found in homes where they are intended to be used by minimally trained or untrained individuals.
Wearable external defibrillators are used to reduce sudden arrhythmic death when the risk is either temporary (for instance, pending heart transplant) or insufficient to warrant implanting an implantable cardioverter defibrillator (ICD). Some ICD candidates who refuse surgery are willing to use wearable external defibrillators.