An Automated External Defibrillator (AED) is a portable medical device designed to deliver an electrical shock to individuals experiencing sudden cardiac arrest. This life-threatening condition occurs when the heart abruptly stops beating effectively, preventing blood flow to the brain and other vital organs. An AED analyzes the heart’s rhythm and, if necessary, provides a controlled electrical shock to help restore a normal heart rhythm. The rapid and correct application of an AED, particularly the precise placement of its pads, is crucial for improving survival outcomes during such emergencies.
Understanding AED Pads
AED pads are adhesive electrodes. These pads contain sensors that monitor the heart’s electrical activity, transmitting this information to the AED’s internal computer. If the AED detects a shockable rhythm, the pads then deliver the therapeutic electrical current.
The design of AED pads ensures that the electrical current passes effectively through the heart muscle. There are typically two main types of pads: adult pads and pediatric pads, with this article focusing on adult pads. Proper placement is paramount because incorrect positioning can reduce the shock’s effectiveness or even cause harm by not directing the current through the heart.
Step-by-Step Pad Placement
When responding to an adult in sudden cardiac arrest, begin by calling emergency services and ensuring the scene is safe. Once the AED is retrieved, the patient’s chest must be exposed by removing all clothing to allow direct skin contact with the pads. It is also important to quickly dry the chest if any moisture is present, as water can interfere with electrical conduction and pad adhesion.
Next, open the AED pad package and peel the protective backing from the adhesive side of the pads. Most AED pads have diagrams illustrating their correct placement. Place the first pad on the upper right side of the patient’s chest, specifically just below the collarbone and to the right of the breastbone. This position is part of the standard anterior-lateral placement.
The second pad should be placed on the lower left side of the patient’s chest. Position it under the armpit, a few inches below, ensuring it rests on the rib cage and avoids contact with the first pad. It is important that the pads do not touch each other, as overlapping can reduce the effectiveness of the electrical current. After placing both pads, firmly press down on their entire surface to ensure complete adhesion to the skin. Finally, connect the pad cable to the AED unit, which will then begin to analyze the heart rhythm and provide further voice prompts.
Important Considerations for Pad Placement
Several factors can affect AED pad adhesion and electrical conduction, requiring specific adjustments. If a patient has excessive chest hair, it can prevent the pads from making good contact with the skin. In such cases, quickly shave the area where the pads will be placed; many AED kits include a small razor for this purpose.
For patients with implanted devices like pacemakers or implantable cardioverter-defibrillators, avoid placing an AED pad directly over the device. These devices typically appear as a small bump under the skin, often in the upper chest. Position the pad at least one inch (approximately 2.5-3 cm) away from any visible bump or scar to ensure the shock is delivered effectively and safely.
Any medication patches on the chest area should be removed with a gloved hand and the skin wiped clean before pad application, as patches can block electrical current and potentially cause burns. While jewelry and underwire bras generally do not need to be removed unless they directly interfere with pad placement, it is prudent to ensure pads are not placed directly over any metallic objects to prevent burns or interference.