An Automated External Defibrillator (AED) is a portable device designed to save lives during sudden cardiac arrest by delivering an electrical shock to restore a normal heart rhythm. For every minute defibrillation is delayed, the chance of survival decreases by approximately seven to ten percent, making quick and effective use paramount. However, even with the device’s voice prompts and user-friendly design, common errors can compromise its effectiveness and waste precious time. Understanding the most frequent mistakes allows rescuers to avoid them, maximizing the AED’s life-saving potential.
The Most Common Error: Failure to Ensure Pad Contact
The single most common and detrimental error when using an AED is the failure to achieve proper, complete contact between the electrode pads and the patient’s skin. This contact is necessary to form an effective circuit, which allows the therapeutic electrical current to pass through the heart muscle. Without this firm adhesion, the electrical resistance, known as transthoracic impedance, increases significantly.
Obstacles on the chest surface, such as excessive hair, moisture from sweat or water, and transdermal medication patches, act as barriers to conductivity. When the pads do not fully adhere, the AED may fail to accurately analyze the heart’s rhythm or, more critically, the delivered shock may be ineffective. The electrical energy can be diverted, resulting in an inadequate dose reaching the heart, or the AED may simply display an error message like “Check Electrodes” or “Connect Electrodes,” stalling the life-saving process.
Studies suggest that a force of around 80 Newtons is needed to ensure adequate pad adhesion, a level easily prevented by a dense layer of chest hair or a wet surface. This poor contact can sometimes result in small sparks or burns on the skin, which indicates the electrical energy is not being properly transmitted through the body. The time lost troubleshooting an error message caused by poor contact directly decreases the patient’s chance of survival.
Essential Preparation Steps Prior to Application
Addressing the issue of poor pad contact requires a few rapid and systematic preparation steps before adhering the electrodes.
Exposure and Drying
The chest area must be quickly and thoroughly exposed by removing or cutting away all clothing. Any moisture, such as pooling sweat or water, should be wiped away immediately using a towel or cloth to ensure the skin is dry.
Hair and Medication Removal
If the patient has excessive chest hair where the pads need to be placed, it must be removed to allow the adhesive to stick directly to the skin. Most AED kits include a small, disposable razor for this purpose, and a quick shave of the two pad areas is far faster than struggling with pads that will not adhere. Medication patches, such as nitroglycerin or pain patches, must be removed with a gloved hand and the area wiped clean, as they can block current flow and pose a burn risk.
Correct Pad Placement
The correct pad placement must be confirmed, which varies slightly depending on the patient’s size. For adults, the standard anterolateral placement is used: one pad on the upper right side of the chest, just below the collarbone, and the other on the lower left side of the ribcage below the armpit. For small children or infants, pediatric pads should be used, if available, in an anterior-posterior configuration—one pad on the center of the chest and the other on the back between the shoulder blades—to prevent pad overlap and reduce the energy delivered.
Procedural Mistakes That Delay Treatment
Beyond preparation errors, certain procedural mistakes during the AED sequence can delay the delivery of the shock, which is timed to maximize survival. The smooth, uninterrupted flow of the resuscitation sequence is paramount to improving the patient outcome.
Interrupting CPR
One common error is the failure to continue high-quality chest compressions until the very moment the AED instructs the rescuer to stop for analysis. Prolonged interruptions in cardiopulmonary resuscitation (CPR) deprive the heart and brain of oxygenated blood, reducing the likelihood of successful defibrillation.
Safety and Analysis Interference
Another mistake is neglecting to ensure complete safety before delivering the shock. When the AED announces it is analyzing or preparing to shock, the rescuer must loudly and clearly announce “All Clear” and visually confirm no one is touching the patient, the bed, or any connected equipment. Failing to remove hands from the patient during the analysis phase can interfere with the AED’s ability to read the heart rhythm, while touching the patient during the shock poses a serious safety risk to the rescuer.