An Automated External Defibrillator (AED) is a portable emergency device used to stabilize the heart’s rhythms and restore circulation during Sudden Cardiac Arrest (SCA). It works by analyzing the victim’s heartbeat to detect arrhythmia (irregular heartbeat) and instructing the user to deliver an electric shock to restore heart function.
With early intervention using an AED, the patient can be stabilized before professional emergency personnel arrives, which can significantly improve their chances of survival. If a child suffers cardiac arrest, also called circulatory arrest, there are certain differences in how an AED should be used.
As far as AEDs are concerned, a child is considered to be someone aged between 1 and 8 and who weighs no more than 55 pounds, while an infant is someone under 1 year of age. A manual defibrillator, which allows the user to control the level and timing of the electric shock, should be used on an infant instead of an AED unless one is not available.
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How does an AED work?
In some US states, AEDs are required in public and recreational areas such as schools, fitness centers, and workplaces. They should be easily visible and accessible for use by the general public in the case someone in the vicinity has a heart attack.
While the general appearance of AEDs can differ depending on the manufacturer, all AEDs will have the same essential components. AEDs typically consist of:
- An electrical box with an ON/OFF button or switch
- Self-adhesive electrode pads
- Connection cords
- A display screen for visual and/or audio instructions
- A shock button
An AED works by analyzing a person’s heart rhythms to determine whether or not there is a cardiac arrhythmia (irregular heart rhythm), and to instruct the user on how to proceed, i.e. if and when to deliver an electric shock.
AEDs can detect the presence of the two main arrhythmias responsible for cardiac arrest:
- Ventricular Tachycardia (VT — rapid heart rate of more than 100 beats per minute).
- Ventricular Fibrillation (VF — cessation of heartbeat and loss of pulse).
Once the AED has identified cardiac arrhythmia, it provides the user with the appropriate instructions to either administer an electric shock or continue Cardiopulmonary Resuscitation (CPR). This electric shock resets the heart’s rhythm and restores circulation. When administered early, this intervention can significantly improve the victim’s chances of survival after hospital admission.
Learning how to use an AED
AEDs are designed to be straightforward and accessible for use by members of the general public. Although any adult bystander can safely use an AED, it can be difficult to operate, particularly with the added stress and urgency of an emergency situation.
You can learn how to use an AED through in-person classes, instructional videos, or web-based tutorials. Emergency dispatchers can instruct lay bystanders on how to use an AED over the phone, but intervention is more effective when the user has prior knowledge or experience with operating an AED.
Sudden Cardiac Arrest (SCA) in children and babies
SCA in children and infants is rare. Understanding when and how to intervene is crucial to improving the child’s chances of survival. It´s also helpful to understand the potential symptoms and causes of SCA in children so that the self-adhesive AED pads can be applied and the machine kept on hand if cardiac arrest appears imminent.
Some common symptoms preceding SCA in children are:
- Chest pain
- Loss of consciousness
- Breathing difficulty
In most cases of SCA, at least one cardiovascular symptom is present prior to cardiac arrest. On average, such symptoms can occur 30 months prior to the episode. Events of unexplained and undiagnosed seizures can also be a precursor to SCA.
Causes of SCA in children and babies
SCA can occur in children who have no previous medical history. There is no clear link between athletic activity and an increased risk of SCA. SCA often occurs during sleep and is uncommon during or after exercise.
One prevalent risk factor for SCA is having a family history of unexpected and premature death — for example, having a family member who suffered Sudden Cardiac Death (SCD) before age 50.
The causes of SCA can vary depending on the child’s age. For children under 2 years old, congenital heart disease is the most common cause of SCA. Primary arrhythmia (an inherited cardiac syndrome) and cardiomyopathy (disorder of the heart muscle) are more common causes than congenital heart disease for older children.
AEDs and pediatric SCA
The use of AEDs, along with Cardiopulmonary Resuscitation (CPR), in episodes of SCA is crucial to preventing death and improving outcomes for survivors. The survival rate can increase from 25 to 58 percent with electric shock intervention delivered by an AED. Survival rates directly correlate with reducing the delivery time of the electric shock — the earlier the intervention, the greater a child’s chances of survival.
AEDs are made to be used on adults, but those installed in settings for children like schools and daycares should include pediatric pads. Pediatric pads should be used on children aged between 1 and 7, while adult pads can be used on children 8 and over and those who weigh more than 55 pounds.
Pediatric pads deliver a lower electrical current than adult pads, making defibrillation safer for children. If no pediatric pads are available, adult pads can be used. Never use pediatric pads on an adult as the energy level will not be sufficient to shock and reset the heart.
Unlike adult pads, which are placed on the front and side of the chest, pediatric pads should be placed with one on the front of the chest in the center, and the other on the back. Ensure that the pads do not touch and that there is no saline or isopropyl alcohol on the front or back which can divert the electrical current away from the heart.
AED usage on children
- Place the self-adhesive pads on the child’s chest and back, ensuring correct placement.
- Plug the pads into the machine.
- Allow the AED to analyze the cardiac rhythm and stand clear as not to disturb the accuracy of the AED with background motion.
- Follow the instructions provided by the AED and deliver an electric shock if prompted to do so. While the machine is charging, continue performing chest compressions. Stop compressions before pressing the shock button.
- Instruct any bystanders to stand clear of the patient and remove any flammable materials within 1 meter while the shock is being delivered.
- Resume CPR immediately after the shock has been delivered while the AED reassesses the cardiac rhythm.
Berg MD, Schexnayder SM, Chameides L, Terry M, Donoghue A, Hickey RW, Berg RA, Sutton RM, Hazinski MF; American Heart Association. Pediatric basic life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Pediatrics. 2010 Nov;126(5):e1345-60. doi: 10.1542/peds.2010-2972C. Epub 2010 Oct 18. PMID: 20956430; PMCID: PMC3741664.
Kovach J, Berger S. Automated external defibrillators and secondary prevention of sudden cardiac death among children and adolescents. Pediatr Cardiol. 2012 Mar;33(3):402-6. doi: 10.1007/s00246-012-0158-2. PMID: 22302278.
Meyer L, Stubbs B, Fahrenbruch C, Maeda C, Harmon K, Eisenberg M, Drezner J. Incidence, causes, and survival trends from cardiovascular-related sudden cardiac arrest in children and young adults 0 to 35 years of age: a 30-year review. Circulation. 2012 Sep 11;126(11):1363-72. doi: 10.1161/CIRCULATIONAHA.111.076810. Epub 2012 Aug 10. PMID: 22887927.