An automated external defibrillator, or AED, is a portable medical device designed to treat individuals experiencing sudden cardiac arrest (SCA). This condition occurs when the heart’s electrical system malfunctions, leading to chaotic rhythms such as ventricular fibrillation or ventricular tachycardia, which prevent the heart from effectively pumping blood. An AED analyzes the heart’s rhythm and, if necessary, delivers a controlled electrical shock to help restore a normal heartbeat. Knowing how to use an AED and, equally important, what to avoid, is important for safe and effective use during a cardiac emergency.
General Safety Precautions During Use
Before delivering an electrical shock, ensure no one is touching the patient or the defibrillator unit. Rescuers should loudly announce “clear” to confirm all bystanders are at a safe distance and not in contact with the individual. This prevents accidental electrical conduction to others, which could cause injury.
The AED pads must be placed directly onto the patient’s bare chest. Any clothing covering the chest area should be quickly removed to allow for direct skin contact and proper adhesion of the pads. Avoid touching the patient during the AED’s rhythm analysis phase, as any movement or contact could interfere with the device’s ability to accurately assess the heart’s electrical activity.
Follow the AED’s voice prompts and visual cues precisely. These prompts guide the user through each step of the process, from attaching pads to delivering a shock. Some AED models require the user to press a button to deliver the shock after the device advises it, while others may automatically deliver the shock after a warning. Adhering to these instructions ensures successful defibrillation.
Specific Patient and Environmental Considerations
When placing AED pads, avoid positioning them directly over implanted medical devices such as pacemakers or implantable cardioverter-defibrillators (ICDs). These devices create a raised area on the chest, and placing a pad directly over them could interfere with the shock delivery or potentially damage the implanted device. Instead, position the pads slightly to the side of these implants.
Any transdermal medication patches, such as nitroglycerin or nicotine patches, located on the chest where the pads will be placed, should be removed. The medication or patch material can block proper electrical conduction from the pads to the skin, potentially reducing the effectiveness of the shock. A quick wipe with a towel or glove can remove any residual medication after patch removal.
Ensure the patient and the immediate surrounding area are dry. Water is an electrical conductor, and moisture can divert the electrical current away from the heart, making the shock less effective. It also poses a significant risk of electrical shock to rescuers or bystanders. If the patient’s chest is wet, quickly dry it before applying the pads.
While large metal jewelry that could interfere with pad placement should be removed, small metal items do not pose a significant risk and should not delay defibrillation. For infants and young children (under eight years old or weighing less than 55 pounds (25 kg)), use pediatric-specific AED pads or a device with an attenuated shock setting if available. These pads deliver a lower energy shock, which is appropriate for smaller body sizes and prevents excessive energy delivery. Using adult pads on young children without attenuation should be avoided, as they deliver a higher energy level that may be too strong for a child.
Common Mistakes and Misconceptions
One common mistake is delaying the use of an AED while waiting for professional medical assistance. Time is important in cardiac arrest; the probability of survival decreases by approximately 7% to 10% for every minute defibrillation is delayed. Immediate application of an AED, combined with cardiopulmonary resuscitation (CPR), can significantly improve survival rates. Therefore, if an AED is available, it should be deployed without hesitation.
A prevalent misconception is the fear of harming the patient by delivering an unnecessary shock. AEDs are sophisticated devices designed to analyze the heart’s rhythm and will only deliver a shock if a shockable rhythm, such as ventricular fibrillation, is detected. They are programmed not to shock a person with a normal heart rhythm or a rhythm that does not require defibrillation. This built-in safety mechanism prevents accidental or inappropriate shock delivery.
Some individuals believe that extensive training is required to operate an AED effectively. While formal training can boost confidence and proficiency, AEDs are specifically designed for use by laypeople and provide clear, step-by-step voice prompts and visual instructions. These user-friendly features enable untrained individuals to respond to a cardiac emergency.
Another oversight is failing to call emergency services, such as 911, immediately after recognizing a suspected sudden cardiac arrest. While preparing and using the AED, someone should simultaneously contact emergency responders. This ensures that trained medical professionals are en route to take over patient care and provide advanced medical interventions. The notion that AEDs are only for “professionals” is incorrect; they are public access devices intentionally placed in many public locations for use by anyone witnessing a cardiac arrest event.