An Automated External Defibrillator (AED) is a portable device used to deliver an electrical shock to the heart, which can interrupt a life-threatening abnormal rhythm and potentially restore a normal heartbeat. While cardiac arrest is less common in infants than in adults, it is a devastating event that requires immediate intervention for any chance of survival. The quick use of an available AED is a deciding factor in these situations. Understanding the correct equipment and procedure is important, especially when dealing with the significant physiological differences between an infant and an adult.
Understanding Pediatric vs. Adult AED Energy Levels
The fundamental difference between adult and pediatric defibrillation lies in the required electrical dosage, which is measured in joules. Adult AEDs are configured to deliver a high-energy shock, typically between 150 to 200 joules, necessary to effectively restart a larger adult heart muscle. This energy level is far too high for a small infant, creating a significant risk of causing damage to the heart muscle or surrounding tissues.
Pediatric pads or keys are specifically designed to address this difference by acting as an energy attenuator. These special attachments reduce the energy output of the AED to a level appropriate for a child, generally less than 55 pounds (25 kg) or under eight years old. Many AEDs automatically switch to a pediatric mode, delivering a reduced shock of approximately 50 joules when the pediatric pads are connected. This reduced energy is tailored to the smaller body mass and heart size of an infant, maximizing the chance of successful defibrillation while minimizing harm.
When Adult Pads Must Be Used on an Infant
While pediatric-specific equipment is always the preferred choice, a sudden cardiac emergency demands immediate action, and the priority is to defibrillate the heart as quickly as possible. Major health organizations agree that if pediatric pads or a key are not immediately available, the adult pads must be used on an infant. The risk of delivering a higher-energy shock is significantly less than the near-certain fatality that results from delaying treatment for a shockable heart rhythm.
Defibrillation is the only treatment that can correct the underlying electrical problem. When adult pads are used, it is important to ensure the pads do not touch each other on the infant’s small chest. Pad overlap can cause the electrical current to short-circuit between the pads rather than pass through the heart, rendering the shock ineffective. Immediate action is prioritized over waiting for the perfect equipment.
Essential Safety: Proper Pad Placement for Infants
Correct anatomical placement is essential for the electrical current to travel effectively through the heart tissue. Standard adult placement involves putting both pads on the front of the chest, but this arrangement is often impossible on an infant due to the size of adult pads. The large adhesive surface of adult pads would likely touch or overlap on a small chest, preventing the AED from functioning correctly.
The recommended method for infants, regardless of pad type, is the anterior-posterior or trans-thoracic placement. This technique involves placing one pad on the center of the infant’s chest (anterior position). The second pad is then placed on the infant’s back, specifically between the shoulder blades (posterior position). This front-and-back configuration ensures the electrical pathway surrounds the heart without the pads coming into contact with one another. This placement is particularly important when using larger adult pads, as it maximizes the distance between them.