An Automated External Defibrillator (AED) is a medical device designed to restore a normal heart rhythm in a person experiencing sudden cardiac arrest. It works by delivering an electrical shock to interrupt ventricular fibrillation, allowing the heart to pump blood effectively. AED placement involves two distinct areas: the macro-placement of the device within a facility and the micro-placement of its pads on the patient’s body. Both locations aim to maximize the chance of survival during a cardiac emergency.
Strategic Placement in Public Spaces
The location of an AED in a public area is guided by the “3-minute rule” for rapid intervention. Survival rates decrease dramatically for every minute defibrillation is delayed, so the device must be retrieved and applied within three minutes. This means the AED should be no more than a 90-second round-trip walk from any potential cardiac event location.
AEDs must be situated in highly visible and easily accessible areas, avoiding locked doors or special access codes. High-traffic zones, such as main entrances, lobbies, and central hallways, are prime locations for quick access. Placement should also prioritize areas where physical exertion is common, like fitness centers or large assembly halls, due to the higher risk of cardiac events.
Proper signage ensures the device is found without delay. The AED should be marked with the universal symbol: a green square featuring a white heart and a lightning bolt. The device must be housed in a well-lit, wall-mounted cabinet to maximize visibility, especially in areas with poor lighting or at night.
Applying the Pads to Adults
The standard method for attaching AED pads to an adult is the anterior-lateral placement, which ensures the electrical current passes directly through the heart muscle. The patient’s chest must first be exposed and dried to ensure optimal adhesion and conductivity, as body hair or moisture can impede the shock’s effectiveness.
The first electrode pad is placed on the upper right side of the chest, just below the collarbone and to the right of the breastbone. This position avoids bony structures, which can interfere with the current’s flow.
The second pad is affixed to the lower left side of the chest, positioned along the mid-axillary line, roughly below the left breast and to the side. This diagonal arrangement creates the shortest, most direct pathway for the electrical current to travel across the heart.
Specifics for Pediatric Patients
Placement for pediatric patients (children under eight or weighing less than 55 pounds) must be adjusted due to their smaller size and the need for a reduced energy dose. Pediatric pads or an attenuation key reduce the shock energy from the adult dose (typically 150-360 Joules) down to about 50 Joules.
The required configuration for children is the anterior-posterior placement, positioning the pads on the front and back of the torso. One pad is placed on the center of the chest over the breastbone. The second pad is placed directly on the back, positioned between the shoulder blades and aligned with the anterior pad.
This front-and-back positioning is necessary because the smaller chest surface area would cause the pads to touch if the adult anterior-lateral placement were used. Overlapping pads would short-circuit the electrical current, bypassing the heart. If pediatric pads are unavailable, adult pads must be used in this anterior-posterior configuration to ensure they do not touch.
Maintaining Readiness and Compliance
Maintaining an operational AED requires consistent checks and adherence to regulatory guidelines. The device must be stored within the manufacturer’s specified temperature range, as extreme heat or cold can degrade the battery and the conductive gel on the pads. Routine visual inspections are necessary to confirm the AED’s readiness indicator light is green and functioning properly.
Timely replacement of consumables is paramount, as both the battery and electrode pads have finite expiration dates. Pads typically expire because the adhesive gel dries out, and battery life is limited regardless of use. Many jurisdictions require AED program registration, which involves notifying local emergency medical services (EMS) or 911 dispatch of the device’s location.