Where should AED pads be placed in the anterior posterior placement for adults and children 8 years and older?

An AED can be used on children and infants and should be used as early as possible for the best chance of improving the chance of survival. Check the AED when it arrives at the scene. Pediatric pads should be used if the person is less than eight years old or less than 55 pounds (25 kg). Standard (adult) pads may be used if pediatric pads are not available. If using standard (adult) pads, do not let the pads touch. For infants less than a year old, a manual defibrillator should be used if available. If a manual defibrillator is not available, an AED may be used. Some AEDs have a switch that can be set to deliver a pediatric shock. If available, turn the switch on when using on children younger than eight years old. If the AED cannot deliver a pediatric shock, an adult shock should be given. It is important to remember an electric shock may be the treatment for a fatal heart rhythm.

AED Steps for Children and Infants

1. Retrieve the AED (Figure 12a).
   • Open the case.
   • Turn on the AED.
2. Expose the person’s chest (Figure 12b).
   • If wet, dry the chest.
   • Remove any medication patches.

3. Open the Pediatric AED pads (Figure 12c).

• Peel off backing.
• Check for pacemaker or implanted defibrillator.

4. Apply the pads (Figure 12d).

• Apply one pad on the upper right chest above the breast. For infants, apply on the front of the chest.
• Apply the second pad on the lower left chest below the armpit. For infants, apply a second pad to the back (Figure 12e).

5. Ensure wires are attached to the AED box (Figure 12f).

6. Move away from the child (Figure 12g).

• Stop CPR.
• Instruct others not to touch the child.

7. Let AED analyze the rhythm.

8. If the AED message reads “Check Electrodes,” then:

• Ensure electrodes make good contact (Figure 12f).

9. If the AED message reads “Shock,” then:

• Press and hold the flashing shock button until the shock is delivered.

10. Resume CPR for two minutes starting with chest compressions (Figure 12h).

11. Repeat steps 1-10.

Defibrillator Pad Placement

Optimizing Current Delivery

In sudden cardiac arrest (SCA), the heart stops beating in a productive manner and is unable to efficiently pump blood to the brain and other vital organs. Rescuers must shock the heart with enough current from an automated external defibrillator (AED) or manual defibrillator to interrupt the irregular activity and allow the heart to resume a normal cardiac rhythm.

Electrodes, commonly referred to as pads, adhere to a victim’s chest and connect to a defibrillator. The pad allows the AED to analyze a heart’s rhythm, and if necessary, conduct current to the heart.

Careful pad placement allows for the most direct and unobstructed path of transthoracic current (TTC). Improper pad placement and the presence of a variety of substances can create resistance to current flow, also called transthoracic impedance (TTI). This guide explains pad placement and other important considerations to keep in mind when defibrillating adult and pediatric SCA victims.

Positioning Pads on Adults

Both adult and pediatric electrodes come packaged with simple graphics showing placement that will optimize the delivery of current. Electrode placement may vary by manufacturer, so be sure to review your electrode's instructions before you find yourself in a rescue situation.

In general, however, the American Heart Association (AHA) recommends two basic ways to position pads when treating adult victims: anterior-lateral and anterior-posterior.1 When pads are placed anterior-laterally, or front-side, one electrode is placed on the victim’s upper right torso above the right nipple, just below the clavicle, and the other (lateral) pad should align with the bottom portion of the pectoral muscle on a male patient or under the breast on a female patient.

Alternatively, rescuers may choose to place pads in an anterior-posterior position, or front-back. Place the posterior pad to the left of the spine just below the scapula at the heart level. Place the front pad over the cardiac apex between the midline of the chest and nipple on a male victim or under the breast on a female. Both arrangements allow the AED to analyze the victim’s heart and deliver a shock if necessary.

ZOLL® Electrodes

When using the ZOLL defibrillator, rescuers should attach pads to victims as indicated on the packaging of the ZOLL electrodes:

1. Place one electrode to the right of the patient’s sternum (patient’s right), just below the clavicle.
2. Place the other electrode just below and to the left of the patient’s left nipple, along the anterior-axillary line.

Positioning Pads on a Child

Children suffering from sudden cardiac arrest are treated in the same fashion as adults, with one significant difference. Because children require less energy during defibrillation, the current delivered must be attenuated, or reduced, through the use of specially designed pediatric pads. For this reason, the AHA recommends that any child under 8 years of age should be defibrillated using pediatric pads.2

It is also important that electrodes don’t overlap or make contact during defibrillation. A child’s smaller physical size can make it a challenge to position both electrodes on the chest without any overlap. To ensure safe pediatric defibrillation, the best location for pads is the anterior-posterior (front-back) configuration.  One electrode is placed on the front (anterior) chest wall and the other on the center of the child’s back (posterior)

The American Heart Association (AHA) states anterior-lateral placement or anterior-posterior placement may be reasonable to defibrillate pediatric victims,2 however ZOLL pediatric electrodes are designed to be used in anterior-posterior placement as shown in the images below. Attach the back pad center along the spine of the victim. Attach the front pad over the cardiac apex between the midline of the chest and nipple.

Pad size

In an emergency, EMS rescuers should always act as quickly as possible, using the electrodes provided with the defibrillator at hand. To ensure that your AED is properly outfitted with appropriately sized adult and pediatric electrodes, the American Heart Association offers some guidance:

• Larger electrodes have been shown to lower transthoracic impedance, so the AHA suggests using adult electrodes that are between 8–12 cm (3.14–4.72 inches)  in diameter.1
• To achieve the best outcomes when defibrillating a child, pediatric electrodes should also be as large as possible, while still providing 3 cm (1.18 inches) of space between the edges of the pads.
• When defibrillating infants and small children under 8 years of age or weighing less than 25 kg (55 lb), the AHA recommends using pediatric electrodes. 2

Elements of Successful Defibrillation

In addition to appropriate pad size and position, there are other factors EMS and hospital clinicians need to consider when preparing to defibrillate a victim.

Above all, it is important to make sure that the pads are completely adhered to the victim’s skin. Air pockets or gaps between skin and the pads can lead to the possibility of arcing and burns. To avoid this, apply one edge of the pad securely to the patient. Roll the pad smoothly from the applied edge to the other, being careful not to trap any air pockets between the pad and the skin.

Items on a victim’s body can interfere with the delivered current and some elements can even create impedance, or resistance, to current. To ensure the best possible outcome, pay close attention to the following list and quickly prepare the victim prior to defibrillation:

Jewelry: Remove all of a victim’s metal jewelry, including nipple piercings and necklaces, that may come in contact with electrodes.1

Chest hair: If the victim has excessive chest hair, rapidly shave it with the razor provided with the AED before you apply pads to ensure proper adhesion. Those who are at risk for or who have already experienced SCA are encouraged to regularly remove chest hair.3

Breast tissue: Significant breast tissue can contribute to impedance. To accommodate for this, the AHA recommends placing the electrode beneath the tissue, using one hand to elevate the breast tissue and the other to apply the pad.3

Moisture: Excessive moisture can interfere with adhesion and electricity conduction. Move the victim and the AED away from sources of water, remove any wet clothing, and dry the victim to the best of your ability before applying electrodes.

Adequate pressure: Pad placement depends on adequate pressure. Studies have recommended that at least 80 N of force be applied when adhering pads to a victim, so it’s best to press down as firmly as possible to ensure proper application.4

These guidelines should help you respond in the event of an SCA. For further information, always refer to your AED manual or the American Heart Association website.

1Panchal AR, et al. Circulation. 2020;142:16:S366–S468.
2Topjian AA, et al. Circulation. 2020;142:16:S469–523.
3Jacobs I, et al. Circulation. 2010;122:16:S325–S337.
4Sado DM, et al. J R Soc Med. 2005;98:1:3–6.

Additional Resources

What Is Advanced Life Support
What Is Basic Life Support
How to Maintain an AED
ZOLL Accessories

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