3.1 AED Operation, Pad Placement & CPR Integration

3.1 AED Operation, Pad Placement & CPR Integration

An AED analyzes the heart's electrical rhythm and advises a shock when its algorithm identifies a shockable pattern. The BLS provider's job is to apply the device quickly, protect everyone from contact during analysis and shock, and keep interruptions in compressions as short as possible.

Standard operating sequence

1. Turn on the AED. Open the lid or press the power button according to the device.
2. Expose the chest. Remove clothing so pads adhere directly to skin.
3. Attach the pads. Use the diagrams printed on the pads or package.
4. Connect the cable if the model requires a separate connector.
5. Clear for analysis. Stop compressions and ensure no one touches the patient.
6. If shock advised, clear again and deliver the shock as directed.
7. Resume CPR immediately, beginning with compressions.

AED models differ. Some deliver the shock automatically after warning; others require the rescuer to press a flashing shock button. Follow the prompts for the device in front of you rather than relying on a memorized button sequence.

Adult pad placement

Standard adult anterolateral placement is:

• One pad on the patient's upper right chest, below the clavicle and to the right of the sternum.
• The other pad on the patient's lower left side, below the armpit on the lateral chest.

The pads must stick completely and must not overlap or touch. If the chest is too small for anterolateral pads to fit without contact, follow the pad diagrams or manufacturer direction for an anteroposterior arrangement—one pad on the chest and one on the back. Do not cut pads to make them fit.

Keep compressions going during setup

One rescuer continues high-quality compressions while another turns on the AED, opens the package, and positions the pads. A pad can often be slipped into place while compressions continue. Pause only when the AED announces analysis or when contact would make pad application unsafe.

The compressor should listen for the device's timing so hands come off the chest promptly for analysis. Once the analysis or shock is complete, restart compressions immediately. Do not wait for the AED to say every word if the device has already indicated that it is safe to resume.

Clear commands

Before analysis and before shock delivery, look from head to toe and state a clear warning such as, “Clear.” Confirm that:

• No rescuer is touching the patient.
• Ventilation equipment and oxygen sources are managed according to training and local fire-safety practice.
• No one is contacting the bed, stretcher, or patient in a way that could transmit movement or current.

Touching the patient during analysis can introduce motion artifact and delay a correct decision. Touching during shock delivery can expose a rescuer to current.

What “shock advised” means

AEDs are designed to recognize shockable rhythms such as ventricular fibrillation and pulseless ventricular tachycardia. The provider does not need to identify the rhythm on a display and must not override the device based on appearance. A no-shock message does not mean the patient has a pulse; it means the AED did not identify a shockable rhythm at that analysis.

After either message, resume CPR unless the patient shows signs of life that call for reassessment. The AED typically prompts another analysis after about 2 minutes of CPR.

Safety and maintenance awareness

Before an emergency, teams should know where AEDs are located and confirm that status indicators, pads, and batteries are ready. During use, replace visibly damaged pads or cables if another set is immediately available. Do not stop resuscitation for a lengthy equipment inspection; use a functioning backup AED if the first device fails.

Common errors

• Applying pads over clothing.
• Placing pads so they overlap or touch.
• Stopping compressions throughout AED unpacking.
• Allowing someone to touch the patient during analysis.
• Delaying CPR after a shock to check the pulse routinely.
• Pressing the shock button after a no-shock instruction.

On exam scenarios, the best AED action is usually the one that shortens time to analysis and defibrillation while preserving high-quality CPR and complete clear commands.

AED rehearsal

Use the training AED model that matches local equipment. Start with the trainer closed, have a partner continue compressions, and practice opening it, applying pads, connecting the cable when required, clearing for analysis, and resuming compressions. Repeat with the pads placed on the wrong side of the package so you learn to read the diagrams rather than rely on color or memory. Measure the pause from “clear” to the first resumed compression and work to make every motion deliberate.