When it comes to life-saving tools, few are as critical as Automated External Defibrillators (AEDs). These devices are designed to correct life-threatening heart rhythms and are found in many public spaces, from shopping centers to airports. In this informative blog post, we’ll explore what AEDs are, how they work, and the essential steps to effectively use an AED. While you will learn the basics in this article, it is highly recommended that you take a first aid course, such as OFA Level 1 in Vancouver, BC, 2 to practice using an AED in a controlled setting. So, whether you’re a concerned citizen or a professional first responder, understanding AEDs can make all the difference when faced with a cardiac emergency.
What is an AED?
An Automated External Defibrillator, or AED for short, is a portable device that delivers an electrical shock to the heart in cases of sudden cardiac arrest. Sudden cardiac arrest can be caused by abnormal heart rhythms, specifically ventricular fibrillation (V-fib) and ventricular tachycardia (V-tach). These rhythms disrupt the heart’s ability to pump blood effectively, and without intervention, they can quickly lead to irreversible damage or death.
In more than 80% of all sudden cardiac deaths, the person’s heart rhythm is “shockable” (ventricular tachycardia or ventricular fibrillation). In other words, defibrillation could have helped. If the person’s heart has no electrical activity (asystole or flatline), defibrillation won’t help. For each minute that the person has to wait for defibrillation, the chance of survival drops between 7 and 10%.
How Does an AED Work?
The primary function of an AED is to restore a normal heart rhythm by administering a controlled electrical shock to the heart. Here’s a breakdown of how it operates:
Analyzing Heart Rhythm: Upon attaching the AED pads to the patient’s chest, the device automatically analyzes the heart’s rhythm. Some AEDs start this process immediately, while others require the user to initiate it with a button press.
Shock Delivery: If the AED detects a shockable rhythm (V-fib or V-tach), it will prompt the user to deliver a shock. This shock momentarily disrupts the chaotic electrical activity in the heart, allowing it to reset and hopefully reestablish a normal rhythm.
CPR and Reanalysis: Following a shock or if the AED determines no shock is needed, the user should immediately resume CPR, starting with chest compressions. The AED continues to monitor the heart rhythm and will reanalyze it every few minutes.
When should we use an AED?
The symptoms to look for when trying to decide if someone needs an AED are the same as the ones we use to decide if they need CPR. AED’s are used as a supplement to CPR, so you will be performing CPR while using your AED. The symptoms to look for are:
- Is the person responsive?
- Are they breathing Normally?
If the person is unresponsive and not breathing normally, then you should ensure someone calls 911 and use an AED right away.
Using an AED: Step-by-Step
While AEDs are user-friendly, it’s crucial to know how to operate them correctly. Here’s a step-by-step guide:
- Power On: Turn on the AED. Most AEDs have visual displays and voice prompts to guide you.
- Prepare the Chest: Expose the patient’s chest by removing clothing and objects that might interfere with the pads. Dry the chest if it’s wet.
- Check for a Pacemaker: If the patient has an implanted pacemaker, place the AED pads at least 2.5 cm away from it.
- Apply the AED Pads: Select the appropriate pad size—adult, child, or baby—and follow the pad diagrams for correct placement. Ensure the pads are at least 2.5 cm apart. (Remember, it is safe to use adult pads on children and babies if necessary)
- Analyze Heart Rhythm: Let the AED automatically analyze the heart rhythm without interruptions.
- Deliver the Shock: If the AED advises a shock, ensure no one is touching the patient, and announce, “I’m clear, you’re clear, everybody’s clear,” then press the “shock” button.
- Resume CPR: After delivering the shock, immediately resume CPR, starting with chest compressions.
- Follow AED Prompts: Continue to follow the AED’s automated prompts. It will reanalyze the heart rhythm every few minutes.
Considerations for Safe AED Use
Environmental Considerations
Flammable or combustible materials: Do not use an AED around flammable or combustible materials, such as gasoline or free-flowing oxygen.
Metal surfaces: It is safe to use an AED when the person is lying on a metal surface, as long as the AED pads do not touch the metal.
Water: If the person is in water, remove him or her from the water before using the AED. Remember that many liquids conduct electricity: if the person is lying in a puddle when the shock is delivered, anyone who is touching the same puddle is at risk of being shocked as well. It is safe to use an AED on ice or snow.
Inclement weather: It is safe to use AEDs in all weather conditions, including rain and snow, but their effectiveness can be reduced if the pads are wet. Provide a dry environment if possible (for example, shelter the person with umbrellas), but do not delay defibrillation to do so. An AED is designed to function in a range of weather conditions, but it is still a battery-operated electronic device, and excessive cold, heat, moisture, etc., can result in maintenance errors or prevent the pads from adhering properly. If this happens, move the person into a different environment, if possible, before attempting defibrillation again.
Person-Specific Considerations
Pregnancy: It is safe to use an AED on a woman who is pregnant.
Pacemakers and implantable cardioverter-defibrillators (ICDs): A person who has a known arrhythmia (irregular heartbeat) may have a pacemaker or an ICD. These small devices are surgically implanted under the skin to automatically prevent or correct an irregular heartbeat. You may be able to see or feel the outline of the pacemaker or ICD in the area below the person’s collarbone, or the person may wear a medical identification product indicating that he or she has a pacemaker or ICD. If the person has a pacemaker or ICD, adjust the pad placement to avoid placing the AED pads directly over the device, as this can interfere with the delivery of the shock. If you are not sure whether the person has an implanted device, place the pads as you normally would.
Transdermal medication patches: Some types of medications, including nitroglycerin and smoking cessation medications, are delivered through patches applied to the skin. Remove any medication patches that you see before applying AED pads. Wear gloves to prevent absorption of the drug through your own skin.
Chest hair: Time is critical in a cardiac arrest situation and sparse chest hair rarely interferes with pad adhesion. In most cases, you should proceed as you normally would—attach the AED pads, pressing firmly to ensure adhesion. However, if the person has a great deal of thick chest hair and it seems like it could interfere with pad-to-skin contact, quickly shave the areas where the pads will be placed and then attach the pads.
Jewelry and body piercings: You do not need to remove the person’s jewelry or body piercings before using an AED. However, if possible, avoid placing the AED pads directly over any metallic jewelry or piercings. If making a small adjustment to pad placement allows you to avoid the jewelry then do so, but if you must move the pads significantly it is better to place the pads directly over the jewelry.
Using an AED on Children or Babies
Using an AED on a child or baby follows a similar procedure to that for adults but with some important considerations. First, if possible you should choose the right pad size—some AEDs come with pediatric pads specifically designed for children aged 1 to 8 years or weighing less than 55 pounds. However, if pediatric pads are unavailable or the AED lacks a pediatric setting, it is entirely safe to use adult-sized pads on a child or baby.
Proper pad placement is essential, following the diagrams on the pads for accurate positioning. Maintain a minimum gap of 2.5 cm (1 inch) between the pads. In situations where there isn’t enough space on the child’s chest, place one pad on the front (anterior) and the other on the back (posterior) to ensure they are positioned correctly. Remember that, despite the smaller size, children and babies may still experience cardiac emergencies, making it essential to know how to adapt AED usage to their needs, and every second still counts when it comes to responding effectively to such situations.
Conclusion
Automated External Defibrillators (AEDs) are invaluable tools for saving lives in cases of sudden cardiac arrest. Understanding what they are, how they work, and how to use them is crucial for anyone interested in emergency response. Whether you’re at a shopping center, airport, or sports arena, knowing how to operate an AED can make you a vital link in the chain of survival. Your swift action with an AED can be the difference between life and death, making our communities safer and more resilient.