An Automated External Defibrillator (AED) is a portable device used to treat sudden cardiac arrest (SCA) by delivering an electrical shock to re-establish an effective heart rhythm. SCA occurs when the heart’s electrical system malfunctions, leading to chaotic or absent electrical activity that stops blood flow. The rapid use of an AED is directly correlated with a greater chance of survival because it provides the only definitive treatment for certain life-threatening heart rhythms. Although the mechanics of the device are standardized for all adults, specific anatomical considerations arise when the patient is female. Understanding these adjustments ensures the electrical current is delivered effectively across the heart muscle, maximizing the chances of a successful outcome.
Initial Steps and Patient Preparation
The initial response to a potential sudden cardiac arrest follows a universal sequence. First, the scene must be checked for safety, and the patient must be assessed for responsiveness and normal breathing. If the patient is unconscious and not breathing normally, emergency medical services should be activated immediately, and the AED should be retrieved. While waiting for the device, chest compressions should be initiated at a rate of 100 to 120 compressions per minute if the rescuer is trained.
The AED should be powered on as soon as it arrives, as the device provides voice prompts that guide the rescuer through every subsequent step. The next action involves preparing the patient’s chest to ensure the defibrillator pads can make direct, unhindered contact with the skin. Proper exposure of the chest is necessary to minimize transthoracic impedance, which is the resistance to the flow of the electrical current.
Managing Breast Tissue and Clothing
The primary consideration when preparing a female patient is the management of clothing and breast tissue to ensure bare skin contact for the pads. All clothing covering the chest and torso, including bras and underwire garments, must be quickly removed or cut away using the safety scissors often found in the AED kit. The pads must be applied directly to the skin, as clothing, especially wet fabric, can interfere with the electrical delivery and cause arcing or burns.
It is important to ensure the skin is clean and dry because moisture, such as water or excessive sweat, can also increase impedance and divert the electrical current. If the patient’s chest is noticeably wet, it should be quickly wiped dry before pad application. The presence of significant breast tissue requires a specific technique to ensure the electrode pad adheres to the chest wall and not the tissue itself. The tissue on the lower left side must be gently lifted and moved aside so the pad can be placed on the bare skin underneath, against the ribcage. Placing the pad directly on or under the breast tissue can compromise adhesion and absorb the electrical energy, preventing the therapeutic current from reaching the heart effectively.
Specific AED Pad Placement
Correct placement of the defibrillator pads is paramount because the current must pass directly through the heart muscle to halt the chaotic electrical activity. The standard adult placement, known as anterior-lateral, is the first choice for all adult patients, including women. This configuration aims to sandwich the heart between the two electrodes to maximize the electrical pathway.
The first pad is positioned on the patient’s upper right chest, just below the collarbone and to the right of the breastbone. The second pad is placed on the lower left side of the ribcage, several inches below the breast and slightly to the side, near the armpit area. This positioning ensures that the electrical energy courses across the ventricles of the heart, which is the intended target for defibrillation. The diagrams printed on the pad packaging serve as a visual guide and should be strictly followed.
If the patient’s anatomy, such as very large breasts, makes the standard anterior-lateral placement impossible without the pads touching or overlapping tissue, an alternative method can be used.
Alternative Placement: Anterior-Posterior
The anterior-posterior configuration involves placing one pad on the front of the chest, over the sternum, and the second pad on the patient’s back, between the shoulder blades. This front-to-back placement is equally effective at delivering the therapeutic shock directly through the heart. This alternative is also useful if the patient has an implanted device, such as a pacemaker, that would otherwise be directly under the standard pad location.
Using an AED on a Pregnant Patient
The use of an AED on a woman who is visibly pregnant should never be delayed, as maternal cardiac arrest is immediately life-threatening to both the mother and the fetus. The survival of the fetus is directly dependent on the survival of the mother, making prompt defibrillation the priority. Current medical guidelines confirm that the electrical current from an AED is not expected to cause direct harm to the fetus, and the potential benefit of saving the mother’s life far outweighs any theoretical risk.
The standard adult pad placement, the anterior-lateral position, remains the recommended approach for a pregnant patient. Rescuers should proceed with pad application and defibrillation as with any other adult. A slight modification involves positioning the pads slightly higher on the torso than normal, if necessary, to avoid placing a pad over the enlarged abdomen or uterus, particularly in the later stages of pregnancy. This simple adjustment helps ensure the current is directed through the chest and heart muscle.