Defibrillation is a life-saving medical procedure that uses a controlled electrical shock to correct an abnormal heart rhythm, such as ventricular fibrillation. The shock is delivered through specialized, adhesive pads placed on the patient’s chest to conduct the electrical current across the heart muscle. Modern defibrillators, including Automated External Defibrillators (AEDs), continuously monitor the electrical connection to ensure safe and effective energy delivery. When the monitoring system detects an improper connection or electrical fault, it alerts the user with an error message, such as the “Pad Short” error.
Understanding the “Pad Short” Error
The “Pad Short” error indicates that the defibrillator has detected an abnormally low electrical resistance between the two electrode pads. This means a short circuit has formed, providing an unintended path for the electricity that bypasses the patient’s heart. The defibrillator measures the impedance, or resistance, of the entire circuit, which should include the patient’s chest tissue. If this measured impedance falls below a certain threshold, the device interprets it as a “short.”
When this error occurs, the device halts operation and prevents the delivery of a shock. This protective measure is in place because if the shock were delivered, a significant portion of the electrical energy would follow the path of least resistance across the skin surface instead of passing through the heart. This would make the defibrillation attempt ineffective and could potentially cause severe burns. The “Pad Short” message is a safety warning signaling that conditions are not right for successful electrical therapy delivery.
Common Causes of the Short Circuit
A “Pad Short” error is typically caused by physical factors that create a conductive bridge between the two pads on the patient’s body. This bridge allows electricity to travel across the skin rather than through the chest wall.
Gel Bridging
One of the most frequent causes is gel bridging, which occurs when the conductive hydrogel from one electrode pad spreads and makes contact with the gel or edge of the other pad. Since the gel is highly conductive, this connection creates a low-resistance path on the skin’s surface, resulting in the short circuit detection.
Excessive Moisture
Another common factor is the presence of excessive moisture on the patient’s skin, such as heavy perspiration, water, or other fluids. These liquids act as a conductor, forming a direct electrical pathway across the skin between the two pads. The electrical current follows this moist path rather than penetrating the chest wall, triggering the error.
Improper Placement or Equipment Defect
Improper pad placement is also a frequent cause; if the pads are placed too close together, the distance between the two electrodes is insufficient, which naturally lowers the resistance. In rare instances, a physical defect in the equipment, such as damage to the pad’s cable or a tear in the pad itself, could also create a short.
Immediate Steps to Resolve the Issue
When the defibrillator displays a “Pad Short” error, the immediate response is to pause and safely address the physical connection issue. The first step is to quickly inspect the area around the pads for any signs of gel bridging or excessive moisture. If the skin is visibly wet, a rescuer should rapidly dry the area, preferably by wiping the skin briskly with a towel or gauze. This action removes the conductive bridge on the skin surface.
The pads must be checked to ensure they are not touching and are positioned correctly on the chest, maximizing the distance between them while adhering to proper placement protocol. If the initial inspection and drying do not immediately clear the error, the most decisive action is to replace the pads with a fresh, unopened set. This step eliminates the possibility of a defective pad or a persistent moisture issue. Finally, the pad cable connection to the defibrillator unit should be checked to confirm it is securely inserted.