An Automated External Defibrillator (AED) is a sophisticated, user-friendly medical device designed to treat sudden cardiac arrest (SCA). SCA occurs when the heart’s electrical system malfunctions, stopping the heart from pumping blood effectively. The AED analyzes the heart rhythm and delivers an electrical shock to reset the heart, potentially reversing this life-threatening condition. Despite intuitive design with voice prompts, the high-stress environment often leads rescuers to make procedural errors. Understanding the most common pitfalls is paramount to ensuring the device performs its life-saving function effectively.
The Critical Error: Skin Preparation and Pad Placement
The most frequent procedural error is the failure to properly prepare the victim’s chest, leading to poor electrical contact. Preparation minimizes transthoracic electrical impedance, which is the resistance the electrical current encounters as it travels through the heart. High impedance can result in a weak or failed shock delivery.
The chest must be bare and dry to ensure the adhesive pads fully adhere to the skin. Moisture from sweat, rain, or a water environment acts as a conductor, diverting the shock across the skin’s surface rather than driving the current deep into the heart muscle. This electrical short-circuiting can render the shock ineffective and may even cause superficial burns to the skin.
Excessive chest hair prevents the gel on the pads from making solid contact with the skin. If the pad is applied directly over dense hair, the resulting air gaps increase impedance, which can lead the AED to fail its rhythm analysis or deliver a less potent shock. Most AED kits include a razor to quickly shave the area where the pads will be placed, an action that should not be skipped when necessary.
Improper placement of the pads also disrupts the intended electrical pathway through the heart. For adults, the standard placement is one pad on the upper right side of the chest, just below the collarbone, and the second pad on the lower left side, below the armpit. Placing the pads too close together, or incorrectly using smaller pediatric pads on an adult, prevents the electrical energy from traversing the entire heart muscle. This spatial error means the electrical current bypasses the target tissue.
Safety and Environmental Miscalculations
Errors often extend beyond the victim’s immediate body to the surrounding environment and safety protocols, causing delays or dangerous complications. A person in cardiac arrest must be moved away from water or conductive metal surfaces before the AED is used. Although modern AEDs are safe to use on a metal floor, the pads themselves must not touch any metal that could divert the shock away from the victim.
Ignoring potential hazards on the skin can also be detrimental. Medication patches, particularly those containing nitroglycerin, must be removed before pad placement. The electrical discharge can heat the metallic backing or the medication itself, causing a skin burn or potentially interfering with the shock delivery. Rescuers should use gloves to remove any patches to protect themselves from accidental medication exposure.
Failing to immediately power on the AED upon arrival wastes valuable time. The device must be activated to begin charging and analysis. Furthermore, before delivering a shock, a rescuer must loudly announce “Clear!” and physically ensure no one is touching the victim, the bed, or any connected equipment. This step prevents the electrical current from unintentionally shocking rescuers or bystanders.
Mistakes in Resuscitation Cycle Management
The effective use of an AED requires seamless integration with high-quality cardiopulmonary resuscitation (CPR). A frequent mistake is prematurely stopping chest compressions to apply the AED pads or waiting for the device to fully analyze the rhythm and charge before resuming compressions. This results in an extended “hands-off” time, which reduces blood flow to the brain and heart.
The goal is to minimize this cessation of compressions to under ten seconds during the transition to analysis and shock delivery. Once the AED delivers a shock, or if it advises “No Shock Advised,” rescuers must immediately resume chest compressions. The electrical shock temporarily stuns the heart, and immediate, high-quality CPR is necessary to circulate oxygenated blood while the heart attempts to reorganize its rhythm.
Another error involves the rhythm analysis phase. The AED requires a period of stillness to accurately read the heart’s electrical activity. If the victim is being moved, or if compressions are still being performed, the resulting motion artifact interferes with the analysis. This can cause the AED to deliver an inaccurate reading or prolong the delay to effective treatment. Rescuers should never remove the pads or turn the AED off once attached, as the device provides continuous monitoring until emergency medical services take over.