An automated external defibrillator (AED) delivers an electrical shock to a person experiencing sudden cardiac arrest. This life-saving intervention relies entirely on the electrode pads, which connect the device to the patient’s heart. These single-use, pre-gelled, and sealed components must be fully functional for the AED to analyze the heart rhythm and deliver therapy effectively. Pad failure directly compromises the entire rescue attempt in a time-sensitive emergency.
The Immediate Safety and Effectiveness Concerns
In a life-or-death scenario where no other pads are immediately available, using expired pads is preferable to using no AED at all, as an imperfect attempt offers a chance for survival. However, this action carries significant risk of reduced efficacy. Expired pads may not adhere properly to the skin, especially when chest compressions are being performed, causing them to pull away from the body. This poor contact can lead to the AED being unable to accurately analyze the heart’s electrical rhythm, potentially preventing the device from delivering a necessary shock. Degraded conductivity also increases the resistance to the electrical current passing through the skin, which can elevate the risk of skin burns instead of delivering the required defibrillation to the heart.
Why AED Pads Have Expiration Dates
The expiration date is determined by the physical and chemical stability of the electrode pad materials. The most significant component affecting shelf life is the conductive hydrogel applied to the pad surface. This gel ensures a strong adhesive bond to the patient’s skin and facilitates the efficient transfer of the electrical impulse. Over time, the water-based hydrogel naturally begins to dry out, even when the pads are sealed. This process of desiccation causes the gel’s chemical structure to break down, which significantly reduces both its stickiness and its electrical conductivity. Manufacturers typically set the life expectancy for pads between 18 and 30 months from the date of manufacture. This time frame guarantees the pad will perform optimally, ensuring users replace older pads to maintain the integrity of the conductive pathway and necessary adhesion.
Maintaining AED Readiness and Inventory
Maintaining current AED pads is fundamental to readiness. A regular inspection schedule is recommended, with checks conducted at least once a month to confirm the status of both the pads and the battery. These inspections should include verifying that the protective packaging of the pads is intact and that the expiration date is clearly logged.
Proper storage is necessary to prevent premature degradation. AEDs should be kept in environments that avoid extreme heat, cold, or humidity, as these conditions accelerate the drying out of the conductive gel. Organizations often assign a specific individual or team to oversee the AED program, which includes managing a centralized inventory system for all accessories. This system should log the expiration dates for every set of pads, allowing for proactive reordering well before the current pads expire. When a set of pads reaches its expiration date, they must be immediately replaced with a fresh, sealed set.