Sudden cardiac arrest (SCA) is a life-threatening emergency where the heart suddenly stops beating effectively, often due to an electrical malfunction. An Automated External Defibrillator (AED) is a portable medical device specifically designed to deliver an electrical shock to the heart, which can restore a normal, life-sustaining rhythm. Immediate action with an AED is the single most effective intervention for increasing the chance of survival from SCA. While the fundamental principles of defibrillation apply universally, understanding the standard procedure and specific anatomical considerations for a woman ensures the device can be used with maximum effectiveness and confidence.
Standard AED Operating Procedure
The first step in any cardiac arrest emergency is to confirm the person is unresponsive and not breathing normally, then immediately call emergency services and retrieve an AED. Once the AED is available, it must be powered on; modern devices provide clear voice prompts that guide the user. The person’s chest must be completely exposed by removing or cutting away all clothing, including bras, to ensure the electrode pads adhere directly to the skin. The skin must also be dry, and any excessive moisture like sweat or water should be quickly wiped away before proceeding.
The standard adult electrode pads are then attached to the bare chest, and the connector cable is plugged into the AED unit. The device will then instruct everyone to stand clear while it analyzes the heart’s electrical rhythm to determine if a shockable rhythm is present. If the AED advises a shock, the rescuer must ensure no one is touching the patient and loudly announce “Clear!” before pressing the shock button, or allowing the fully automatic device to deliver it. After the shock is delivered, or if the AED determines no shock is advised, cardiopulmonary resuscitation (CPR) must be immediately resumed, starting with chest compressions.
Optimizing Pad Placement for Female Anatomy
Effective defibrillation requires the electrical current to pass directly through the heart muscle, and this pathway must not be obstructed by tissue that could impede the current’s flow. For women, the presence of breast tissue necessitates a modification of the standard pad placement to ensure proper contact with the chest wall. The primary goal is to place the adhesive electrode pads directly onto the bare skin of the rib cage, ensuring the electrical current does not travel through or across the breast tissue itself. This avoids interference and minimizes impedance.
The most common placement is the anterior-lateral method, where one pad is placed on the upper right side of the chest, below the collarbone. The second pad is placed on the lower left side of the rib cage, typically a few inches below the armpit. For women with larger breasts, the second pad must be positioned underneath the breast, on the flat surface of the rib cage, to achieve correct placement. A practical technique involves gently lifting the breast tissue with one hand and using the other hand to firmly apply the electrode pad beneath it, directly onto the chest wall.
An alternative placement is the anterior-posterior method, which is sometimes preferred to circumvent anatomical challenges. With this method, one pad is placed on the front of the chest in the standard upper-right position. The second pad is positioned on the person’s back, to the left of the spine, just below the shoulder blade. Both methods are designed to bracket the heart, ensuring the electrical energy flows through the myocardium.
Critical Safety Measures and Patient Conditions
Before delivering a shock, ensure the patient is not lying in or near a puddle of water, as this poses a significant safety risk to both the patient and rescuers. The chest area where the pads will be applied should be checked for any large metal objects or jewelry that might interfere with the electrical path. Small pieces of jewelry, such as necklaces, that do not directly contact the electrode pads are generally not a concern, but anything underneath or touching the pads must be removed.
If the person has an implanted medical device, such as a pacemaker or an implantable cardioverter-defibrillator (ICD), a small bulge may be visible under the skin of the upper chest. The AED pads must be placed at least one inch away from this lump to avoid damaging the device and to ensure the shock bypasses the implant’s casing. For patients with a significant amount of chest hair, the AED kit may contain a razor to quickly shave the area, as hair prevents the pads from making solid skin contact and can cause an electrical arc.
Using an AED on a pregnant patient is important, as the mother’s survival is directly linked to the survival of the fetus. The electrical shock is not considered a significant risk to the unborn child. Pad placement should follow the standard adult guidelines, although an effort should be made to avoid placing the pads directly over the abdomen or uterus, if possible, without compromising the correct heart-bracketing position.