An Automated External Defibrillator (AED) is a sophisticated yet easy-to-use medical device designed to treat sudden cardiac arrest (SCA). SCA occurs when an electrical malfunction causes a dangerously irregular rhythm, such as ventricular fibrillation (VF). These erratic rhythms prevent the heart from pumping blood effectively, causing the victim to collapse. The AED analyzes the heart’s rhythm and delivers an electrical shock (defibrillation) to reset the heart and allow a normal rhythm to resume. Clear, step-by-step voice prompts mean even individuals with minimal training can use them effectively.
Initial Response and Device Activation
The first action in any emergency involving a sudden collapse is to confirm the scene is safe and determine the victim’s responsiveness. Check if the individual is unresponsive and not breathing normally, which indicates likely cardiac arrest. Immediate action is paramount, so quickly delegate two simultaneous tasks: calling emergency services (like 911) and retrieving the AED.
Once the AED is available, power the device on immediately to activate the voice prompts. Before applying the pads, expose the victim’s chest completely by removing all clothing. The chest area must be dry and clear of any excess moisture or metal jewelry. If the victim is wet, they must be moved to a dry area and dried off to ensure the electrical current flows correctly.
Pad Placement and Rhythm Analysis
After ensuring the chest is bare and dry, attach the defibrillator pads directly to the skin. For adults, the standard placement is the anterior-lateral position, creating an electrical pathway across the heart. Place one pad on the upper right side of the chest, just below the collarbone, and the other on the lower left side, below the pectoral muscle or breast tissue.
The pads often have diagrams illustrating placement. Once the pads are firmly secured, plug the connector cable into the main AED unit. This establishes the electrical connection necessary for the AED to analyze the heart’s activity.
With the pads connected, the AED automatically begins to analyze the patient’s heart rhythm. During this analysis phase, no one must touch the victim. The machine requires an isolated reading to accurately determine if a shockable rhythm, such as ventricular fibrillation, is present and if electrical intervention is needed.
Shock Delivery and Continued Care
If the AED detects a shockable rhythm, it will advise a shock and begin to charge. Before pressing the shock button, the user must visually and verbally ensure everyone is clear of the patient. A common practice is to loudly announce “I’m clear, you’re clear, everyone clear” to confirm bystander safety.
The user then presses the dedicated shock button, delivering a controlled electrical current intended to briefly stop the heart’s chaotic activity and allow a normal rhythm to resume. If the AED states “No Shock Advised,” the detected rhythm is either normal or non-shockable (like asystole), meaning defibrillation will not work. In this case, the device will not charge and prompts the user to proceed immediately.
Whether a shock was delivered or not, the user must immediately resume Cardiopulmonary Resuscitation (CPR) starting with chest compressions. The AED provides voice prompts and a metronome to guide the user through two minutes of CPR. The pads must remain attached to the patient during this period.
Following the two-minute period of CPR, the AED automatically stops and re-analyzes the heart’s rhythm. The user continues to follow the device’s prompts, administering another shock if advised or continuing CPR, until emergency medical services professionals arrive and take over care. Leaving the pads connected ensures continuous monitoring and allows for further necessary shocks without delay.