Placing AED pads correctly is essential for ensuring that the defibrillator works properly and preventing undue harm to the patient. The correct placement varies between children and adults, though, and there are some unique situations where the general rules don’t apply.
Adult Pad Placement
Older adults are the group most likely to suffer from cardiac arrest. So even though most AEDs have a child setting or are compatible with child pads, these devices typically come equipped with adult pads as the default accessory.
Generally, your defibrillator kit will tell you where to place the pads on adults using both audio prompts and visual diagrams. However, the general rule is to position one pad over the upper right side of the patient’s chest and the other on the lower left side of the patient’s chest (or on the left side of the rib cage). This creates a pathway through the heart muscle that permits the device to shock the heart into action.
AED Pad Placement on an Infant
Infants under one year old are most likely to have a cardiac arrest due to a blockage to the airway or lungs rather than a problem with their heart. One common mistake, though, is to confuse a choking emergency with cardiac arrest. So observe the baby carefully, and if they aren’t clearly choking (in which case apply choking measures first) and an AED is available, using the AED on the infant that is not breathing and has no palpable pulse will be their best chance of survival, even if choking was the initial cause.
Using a set of child pads or a child setting (to adjust the energy level for a pediatric patient), place one pad in the center of the baby’s chest and the other in the center of the baby’s upper back. If only adult pads are available, place them in the same two places, ensuring that the pads don’t touch. Whether or not the AED has a child setting, it’s better to use an adult AED on a baby than do nothing at all.
Child Pad Placement
Children from one to eight years old and/or adults who weigh less than 55 pounds (25kg) should be treated with pediatric pads, if available. Just as with an infant, place one pad in the center of the child’s chest and the other pad in the center of the child’s upper back, making sure that the pads don’t touch.
The main difference between children and infants is the technique for applying cardiopulmonary resuscitation. For a baby, use only two fingers of one hand (pointer and middle), or both thumbs. For a child, use one hand, depending on the size of the child. In both cases, press down to ⅓ of the depth of the child’s chest and watch the chest rise to allow the heart to fill with blood. Rescue breaths should only be attempted if you have been trained in CPR.
AED Pad Placement on a Pregnant Woman
If a pregnant woman goes into cardiac arrest, it is essential to perform CPR and use an AED if one is available. The American Heart Association notes that it is safe to use an AED on an expectant mother. If the mother doesn’t make it, neither will the fetus—unless first-response measures are taken immediately.
To use an AED on a pregnant woman, place one pad above her right breast and place the other pad laterally on the left side of her rib cage. CPR should also be performed as normal for an adult patient, with no modifications. If the patient revives, place the patient on her left side to increase blood flow to the heart and fetus.
When calling 911 for the attention of a pregnant patient, make sure you tell them about her state. If the pregnancy is advanced and the mother dies, it might still be possible to save the baby via an emergency C-section.
AED Pad Placement for Cardiac Arrest Victims with a Pacemaker
Pacemakers are small devices that help some heart patients maintain a normal heart rhythm. While pacemakers can help to treat arrhythmias, they do not regulate fibrillation. If someone with a pacemaker goes into cardiac arrest, it is both necessary and safe to use an automated external defibrillator.
First, locate the position of the pacemaker. Usually, it is installed in the upper left side of the patient’s chest. In this case, there is no need for modification, so apply one pad to the upper right side of the chest and the other on the lower left side of the chest, on the left side of the patient’s rib cage as normal. If the pacemaker is installed in the upper right side of the patient’s chest, place the first pad at least one inch below or to the side of the pacemaker and the second pad on the left side as described.
Anterior-posterior vs Anterolateral
As we’ve seen, the two basic positions for AED pad placement are:
- Anterior-posterior (or “front-and-back”) placement: One on the front and one on the back
- Anterolateral placement: One on the right side of the chest and one on the lower part of the left chest wall (or a few inches below the left armpit, over the ribcage)
The first position is usually used on children, and the second position is used on adults. However, an anterior-posterior placement can be used on adults as well with slightly different pad placement. Instead of placing the defibrillator pads on the center of the chest and back, place one pad just below the left nipple and the second pad on the left side of the back, directly below the scapula (informally known as the “wing bone”).
There are a few basic steps you’ll need to follow beforehand if your patient has a hairy chest, a medicated patch, or wet skin.
If the patient’s chest is especially hairy, the pads might not stick to their skin properly—jeopardizing the electric shock. Before placing the pads on the patient, use a razor to shave the hair where the pads will be placed. Most AED first responder kits include razors.
Electricity and water do not mix, and neither should water and an AED. If the patient is wet, put them on a dry surface, remove their wet clothing, and get the chest dry before applying the pads.
AED pads should not be placed on top of a medicated patch, because the patch could make the electrical shock less effective. Before applying the pads, carefully remove the patch (wearing gloves) and quickly wipe the area with alcohol or a towelette.
If in Doubt, Follow the Instructions Provided for Defibrillator Pad Placement
While there are a few different things to keep in mind, AED pad placement will follow only one of two patterns—front and side or front and back. In both of these cases, the most appropriate position for the AED pads will be illustrated on the pads themselves and all you need to do is follow the electrode pad placement instructions.
The main considerations for placing AED pads are to avoid a pacemaker and medicated patch and ensure the pad is placed on dry, bare skin. Also, remember that an AED should only be used in cases of a cardiac arrest emergency—and not for a heart attack. If you can detect a heart rate or the patient is breathing, don’t try to use a defibrillator.
As long as the basic requirements are met, you can go ahead and deploy the automated external defibrillator with the confidence that the shock could mean the victim’s best chances of survival.