An Automated External Defibrillator (AED) is a user-friendly device designed to deliver an electrical shock to a person experiencing sudden cardiac arrest. This condition often results from an electrical malfunction, such as ventricular fibrillation. Rapid application of the AED significantly increases the chance of survival, as the effectiveness of defibrillation decreases by approximately 10% with every minute of delay. The device temporarily stops the erratic electrical activity, allowing the heart’s natural pacemaker to reset into a normal rhythm.
Powering On the Device
The first action a rescuer must take upon retrieving the AED is to immediately power the unit on. This step is accomplished either by pressing the ‘On’ button or, on some models, by simply lifting the lid or opening the carrying case. Activating the device initiates the sequence of audio and visual prompts that guide the user through every step of the rescue process. These audible instructions are programmed according to established guidelines, making it possible for untrained bystanders to operate the machine effectively.
Following the prompts ensures the correct sequence of actions is performed without hesitation. The voice guidance eliminates the need to memorize complex procedures, directing the rescuer to attach the pads, stand clear during analysis, and deliver the shock when advised. High-quality cardiopulmonary resuscitation (CPR) should be ongoing until the AED is ready to be applied. Quick activation transitions the rescue from basic chest compressions to definitive electrical therapy.
Preparing the Patient for Pad Placement
Once the AED is turned on and issuing prompts, the focus shifts to preparing the patient’s chest for optimal electrical conduction. The chest must be quickly exposed by removing all clothing, including any brassieres, to allow for direct skin contact with the electrode pads. Any moisture, such as sweat or water, must be rapidly wiped away because water increases resistance to the electrical current. Excessive chest hair can also create a barrier, preventing the pads from adhering securely and potentially leading to ineffective shock delivery.
If necessary, a quick shave may be required before pad application. The adhesive pads are then placed according to the diagrams provided. Typically, one pad is placed on the upper right chest, just below the collarbone, and the other on the lower left side, along the ribcage below the armpit. Proper placement ensures the electrical current passes directly through the heart muscle to maximize the success of the defibrillation attempt.
Analyzing the Rhythm and Delivering the Shock
After the pads are firmly affixed to the patient and the connector cable is plugged into the AED unit, the device automatically begins analysis of the heart’s electrical rhythm. During this period, the rescuer must ensure that no one is touching the patient, often signaled by announcing, “Clear!” to the surrounding area. The AED determines if the rhythm is shockable, meaning it detects dangerous electrical activity.
If a shockable rhythm is detected, the device will charge and instruct the user to press the flashing shock button. If no shock is advised for non-shockable rhythms like asystole, the AED will instead prompt the rescuer to immediately resume chest compressions. After a shock is successfully delivered, the rescuer must instantly resume cardiopulmonary resuscitation (CPR) for two minutes before the AED automatically begins its next rhythm analysis cycle.