The use of an Automated External Defibrillator (AED) on a child suffering from sudden cardiac arrest introduces specific challenges. Standard adult AED settings and equipment deliver an energy dose that is excessive and potentially harmful to a small child’s heart. These specialized considerations apply to children typically under eight years old or those weighing less than 55 pounds (25 kilograms). Prompt defibrillation is a time-sensitive intervention, but the correct application of specialized equipment and technique is paramount to ensure both safety and effectiveness.
Pediatric Specific Equipment Requirements
Treating a young child requires reducing the amount of electrical energy delivered to the heart, a process known as attenuation. An adult AED may deliver a shock ranging from 150 to 360 Joules, which is far too powerful for a child. Pediatric guidelines recommend a starting dose of approximately 2 Joules per kilogram of body weight.
Pediatric Attenuated Pads
The most common mechanism is the use of pediatric attenuated pads or cables, which contain a built-in electrical component that physically reduces the energy output from the AED. These specialized pads are often smaller to better fit a child’s chest without touching. They typically reduce the energy dose to a range of 50 to 75 Joules.
Child Key or Switch
A newer mechanism involves AEDs equipped with a child key or switch that internally adjusts the device’s energy output when activated. This feature allows the use of standard adult pads while still delivering the appropriate lower dose for the child. If only adult pads are available and no child key is present, rescuers must proceed with the adult pads and energy dose rather than delaying treatment, as defibrillation is the priority.
Critical Pad Placement Strategy
The physical size of a young child’s chest necessitates a different strategy for pad placement to ensure the electrical current successfully crosses the heart and to prevent the pads from touching. Standard adult placement, known as anterior-lateral, involves placing one pad on the upper right chest and the other on the lower left side. This placement is often impossible in small children because the pads would overlap.
When pads touch, the electrical current may arc between them, bypassing the heart entirely and rendering the shock ineffective. Therefore, the recommended method for children under eight is Anterior-Posterior (Front/Back) placement. One pad should be placed on the front of the child’s chest, typically in the center or slightly to the upper right side below the collarbone.
The second pad is then placed on the child’s back, positioned between the shoulder blades. This front-and-back configuration achieves two objectives: it ensures the electrical pathway runs directly through the entire mass of the heart, and it keeps the pads separated by the body, preventing a short circuit. This is the required placement, particularly if adult pads must be used.
Integrating AED Use into Pediatric CPR
In children, cardiac arrest is most often caused by respiratory failure, unlike adults where it is frequently a primary cardiac event. This difference in cause influences the procedural sequence. For an unwitnessed collapse—the most common scenario—CPR should be initiated immediately with chest compressions and rescue breaths.
If the child’s collapse was not witnessed, the rescuer should perform five cycles, or approximately two minutes, of high-quality cardiopulmonary resuscitation before pausing to apply the AED. This initial period of CPR is intended to circulate oxygenated blood to the heart and brain, addressing the underlying respiratory cause. Once the AED is available, it should be applied quickly during a brief pause in compressions.
After the AED analyzes the rhythm and delivers a shock, the rescuer must immediately resume CPR for another two minutes. Interruptions in chest compressions must be minimized throughout the entire process, including the time taken to apply the pads and charge the device. This continuous cycle of compressions, shocking, and immediate resumption of CPR maximizes the chances of a successful outcome.