An Automated External Defibrillator (AED) is a portable device that delivers an electric shock to interrupt life-threatening electrical rhythms, such as ventricular fibrillation, allowing the heart’s natural pacemaker to restore a normal rhythm. When applying an AED to a child, a critical safety question arises regarding the use of adult pads. The physiological differences between a child and an adult mean the choice between adult and pediatric pads is crucial for both safety and effectiveness.
The Critical Difference: Energy Dosage
The primary difference between adult and pediatric AED pads centers on the amount of electrical energy delivered, which is measured in joules. An adult AED is typically set to deliver a high-energy shock, often ranging from 120 to 200 joules, appropriate for a mature heart and larger body mass. A child’s smaller heart and body require a significantly lower energy dose to avoid potential myocardial damage, a concept referred to as attenuation.
Pediatric pads or a pediatric key/switch are designed to reduce the shock energy, often delivering between 50 and 75 joules. The recommended starting energy dose for a child is approximately 2 joules per kilogram of body weight, demonstrating why a standard adult shock is far too powerful. Pediatric equipment ensures the electrical current remains both safe and effective for children generally defined as under eight years old or weighing less than 55 pounds (25 kg).
Recommended Protocol: Using Pediatric Pads
The ideal procedure for treating a child experiencing sudden cardiac arrest involves using equipment specifically designed for their smaller body size and lower energy needs. This typically applies to children under eight years old or those weighing less than 55 pounds. Pediatric pads are smaller than adult pads, which helps ensure they do not touch each other on the child’s chest, preventing a short-circuit of the electrical current.
Many modern AEDs are equipped with a pediatric key or switch that automatically lowers the device’s energy output to the appropriate level, even if adult pads are attached. If separate pediatric pads are used, they contain an internal mechanism that attenuates the shock energy before it reaches the patient.
Pad Placement
For children, the recommended pad placement is often anteroposterior, with one pad placed on the center of the chest and the other on the back, between the shoulder blades. This placement is particularly important for infants and very small children to guarantee the heart is situated directly within the path of the electrical current. If the child is slightly larger, an anterior-lateral placement (one on the upper right chest, one on the lower left side) can be used, but only if the pads are small enough to avoid touching.
The Emergency Scenario: Using Adult Pads on a Child
In a life-threatening emergency where a child is in cardiac arrest, and only adult AED pads are immediately available, the consensus is to use them without delay. Time is the most critical factor in sudden cardiac arrest, and the risk of death from not delivering a shock outweighs the risk of potential harm from an adult-level dose. Even an unattenuated shock is better than no shock at all for a heart in a shockable rhythm.
When using adult pads on a child, specific placement adjustments must be made to ensure the pads do not overlap and the current passes through the heart. The adult pads should be placed in the anteroposterior position, with one pad on the front of the child’s chest and the other on their back, between the shoulder blades. This arrangement prevents the electrical current from short-circuiting. While the energy delivered will be higher than ideal, rapid defibrillation is the priority.