An Automated External Defibrillator is a device that analyzes the heart’s electrical rhythm and delivers an electrical shock to re-establish a functional heartbeat in cases of sudden cardiac arrest. While cardiac arrest is rare in infants—defined as children under one year of age—it demands a highly specialized, immediate response because the causes are often respiratory failure or shock rather than a primary heart issue. The infant’s small body size means that emergency protocols, particularly the placement of the defibrillation pads, must be followed precisely. Correct and rapid intervention is paramount.
Defining the Infant Protocol and Equipment
The standard definition for a pediatric patient requiring specialized AED settings is typically a child under eight years of age or one who weighs less than 55 pounds (25 kilograms). For an infant, which is a patient under one year old, the use of pediatric pads and settings is mandatory if an AED is to be used. These specialized pediatric electrode pads are smaller than adult pads, which is necessary to ensure they do not touch each other on the infant’s small chest. These pads are also equipped with a built-in electrical component known as an attenuator.
This attenuator reduces the energy delivered from the AED’s standard adult output, typically lowering the dose to about one-fourth to one-third of the adult energy level, often around 50 Joules. This reduction is necessary because a smaller body requires significantly less electrical current to defibrillate the heart, preventing potential damage to the heart muscle. If pediatric pads or an attenuator key are unavailable, adult pads must be used as a last resort, as delivering a shock is better than delivering no shock at all. When using adult pads on an infant, however, placement becomes even more critical to prevent the pads from overlapping or touching, which would cause the electrical current to short-circuit outside the body.
Primary Pad Placement: Anterior-Posterior Method
The preferred and most effective placement method for AED pads on an infant is the Anterior-Posterior (front-back) configuration. This method is specifically designed for smaller bodies to ensure the heart is effectively “sandwiched” between the electrodes, maximizing the current’s path through the vital organ. This placement also virtually eliminates the risk of the pads touching, which is a common hazard on a small chest.
To execute this placement, the infant’s chest and back must first be fully exposed and dried, removing any excess moisture or clothing that could interfere with adhesion or conductivity. The first pediatric pad is applied to the front of the infant’s chest, generally placed centrally over the breastbone, or slightly to the right of the sternum, avoiding the direct center of the heart. The second pad is then applied to the infant’s back, placed between the shoulder blades.
This configuration ensures the electrical current passes directly through the heart muscle, maximizing the chance of correcting the rhythm. When placing the pad on the back, gently rolling the infant onto their side while supporting the head and neck allows for correct positioning without unnecessary movement. The wires connecting the pads to the AED unit must be secured so they do not interfere with subsequent CPR efforts.
Alternative Placement and Procedural Safety
While the Anterior-Posterior method is the gold standard for infants, an alternative placement, known as Anterior-Lateral or Apex, is often utilized for older children (ages one to eight). This method places one pad on the upper right side of the chest, just below the collarbone, and the other pad on the lower left side of the chest, below the armpit, following the adult placement pattern. For an infant, this placement is only considered if the Anterior-Posterior placement is not possible and the pads can be placed without any risk of touching.
Regardless of the chosen pad placement, several procedural safety steps must be strictly followed to ensure the effectiveness of the treatment and the safety of all present. Before applying the pads, the skin must be completely dry, as water can conduct electricity away from the heart or cause arcing. The rescuer must also quickly check for any implanted medical devices, such as a pacemaker, and place the pads at least one inch away from the device to prevent damage to the implant.
Once the pads are correctly attached and plugged into the AED, the device will analyze the heart rhythm. During this analysis and the subsequent shock delivery, it is absolutely mandatory that no one is touching the infant, as the electrical current can pass to bystanders. After the AED delivers a shock, the rescuer must immediately resume high-quality chest compressions and rescue breaths, minimizing the pause in CPR. The AED will prompt for re-analysis every two minutes, and high-quality CPR must continue until emergency medical services arrive or the infant shows obvious signs of life.