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What is AED and How to Use It?

Sudden cardiac arrest is a frightening and life-threatening event that can strike anyone, anywhere, at any time. In such critical moments, having access to an Automated External Defibrillator (AED) can mean the difference between life and death.

In this article, we'll explore what AEDs are, why they're crucial, and how you can confidently use them to save lives.

What is an AED?

An Automated External Defibrillator (AED) is a portable electronic device that delivers a controlled electric shock to a person experiencing sudden cardiac arrest. It's designed to analyse the heart's rhythm and, if necessary, deliver a shock to restore normal heart function.

A typical AED consists of pads, electrodes, a control unit, and a battery. These components work together seamlessly to assess the situation and guide users through the life-saving process.

Why AEDs are Important

AEDs play a vital role in improving survival rates for sudden cardiac arrest victims.

‘In Aotearoa New Zealand, almost 2,500 people are treated for cardiac arrest each year.’ —  St John.

Studies show that the chances of survival decrease by approximately 10% with each passing minute without defibrillation. With AEDs readily available in public places, such as schools, airports, and sports facilities, bystanders can take immediate action before professional help arrives, significantly increasing the likelihood of survival.

How to Use An AED

Using an AED may seem daunting, but it's actually straightforward with proper training. Here's a step-by-step guide:

1.  Assess the Situation: 

  • Ensure the area is safe.

  • Check if the person is responsive and breathing and call 111 for ambulance immediately.

2. Retrieve the AED:

  • Locate the nearest AED. They are often found in public places like airports, malls, and offices. If one is not available, continue CPR until emergency help arrives.

  • Open the case and turn on the AED.

3. Follow Voice and Visual Prompts: 

Most AEDs come with voice and visual prompts that guide you through the process. Listen carefully to the instructions provided.

4. Expose the Chest: 

  • Expose the person's bare chest.

  • Dry it if it's wet.

  • emove any medication patches.

5. Apply Electrode AED Pads: 

  • Remove the electrode pads from the packaging and peel off the backing.

  • Place one pad on the upper-right chest above the collarbone.

  • Place another pad on the lower-left side of the chest, just below the armpit.

6. Ensure Clear Contact: 

  • Make sure that the wires are connected to the AED box.

  • Make sure there are no obstructions (e.g., jewellery, body hair, or clothing) between the pads and the person's skin.

7. Analyse Heart Rhythm: 

  • Allow the AED to analyse the person's heart rhythm.

  • Ensure that no one is touching the person during analysis.

8. Deliver Shock if Advised: 

  • If the AED displays the message ‘Check Electrodes’, ensure that the electrodes are making good contact.

  • If the AED advises a ‘Shock’, ensure that no one is touching the person and press the shock button as instructed.

  • Stand clear while the shock is delivered.

9. Resume CPR: 

After delivering the shock, immediately resume CPR for two minutes, starting with chest compressions.

10. Continue CPR and Follow AED Prompts: 

Continue to follow the AED's prompts, which may include further shocks or CPR cycles, until emergency medical services arrive.


Search for your nearest AED location here:

How to Use an AED for a Child

Using an Automated External Defibrillator (AED) on a child requires special considerations. 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. Here's how to use it:

  1. Follow Standard Procedure: Power on the AED and follow the standard procedure for adults, including pad placement and analysis of heart rhythm.

  2. Select Child Mode (if available): Some AEDs have a paediatric mode. If your AED has this feature, activate it. Paediatric pads and energy levels are used for children under 8 years old or under 55 pounds (25 kilograms).

  3. Adjust Pad Placement: Place one pad in the centre of the child's chest, and the other pad on the child's back, between the shoulder blades.

Training and Certification

It's crucial to receive proper training in AED use and CPR to effectively respond to sudden cardiac arrest emergencies. Many organisations offer AED training courses, including Basic Life Support (BLS) certification, which covers AED use, CPR, and other life-saving techniques. Becoming certified equips individuals with the knowledge and confidence needed to act swiftly and decisively in critical situations.


Wanting to take AED Course:


AED Maintenance and Regulations

Regular maintenance of AEDs is essential to ensure their reliability and effectiveness. This includes regular checks of batteries, pads, and overall functionality.

TESTntel AED service, in partnership with St. John, Red Cross, and Frontera, provides comprehensive maintenance solutions to keep your AEDs in optimal condition.


Learn more about our AED service and pricelist:

How to Check Your AED

Self-Check Processes:

  1. Visual Inspection: Regularly inspect the AED for any physical damage, wear, or signs of tampering.

  2. Indicator Lights: Check if the indicator lights on the AED are functioning correctly, including power, battery, and readiness indicators.

  3. Electrode Pads: Ensure that the electrode pads are sealed and within their expiration date. Replace pads if damaged or expired.

  4. Battery Status: Verify the battery status to ensure it's fully charged or within the recommended operating range.

  5. Self-Test: Initiate a self-test according to the manufacturer's instructions to confirm the AED's functionality.

  6. Recording and Documentation: Keep a record of all self-checks, including dates and any issues encountered. TESTntel offers TELtag, our advanced digital asset management system, to facilitate this process, keep your items recorded with all relevant information.

Hiring a Professional:

  1. Regular Maintenance: Schedule regular maintenance checks by a certified professional, typically annually or as recommended by the manufacturer.

  2. Functional Testing: Our professionals will conduct comprehensive functional testing to ensure all components of the AED are working correctly.

  3. Electrode Pad Replacement: We will replace electrode pads and batteries as needed, ensuring optimal performance during emergencies.

  4. Software Updates: We will update AED software to the latest version, if applicable, to enhance functionality and address any known issues.

  5. Compliance with Regulations: Ensure that the professional conducting maintenance is certified and follows all relevant regulations and guidelines for AED maintenance.


Contact us for more detailed information: 

Why is My AED beeping?

If your AED is beeping, it could indicate several issues:

  1. Low Battery: The AED may beep to indicate a low battery.

  2. Electrode Pad Expiration: Some AEDs beep to alert you when the electrode pads are near expiration or have expired.

  3. Faulty Connection: Beeping may occur if there is a loose or faulty connection between the electrode pads and the AED.

  4. Malfunction: If the AED is malfunctioning or experiencing technical issues, it may beep to alert users of a problem. Contact the manufacturer or a qualified technician for assistance.

  5. Self-Test Reminder: Some AEDs beep periodically as a reminder to perform a self-test. Follow the manufacturer's instructions to conduct the self-test and address any issues detected.

If your AED continues to beep despite troubleshooting, consult the user manual or contact the manufacturer/professional for further assistance.



Automated External Defibrillators are more than just devices—they're instruments of hope and lifesavers in critical moments. By understanding what AEDs are, why they're important, and how to use them, we can all play a role in saving lives.



Ibrahim WH. Recent advances and controversies in adult cardiopulmonary resuscitation. Postgrad Med J. 2007 Oct;83(984):649-54. doi: 10.1136/pgmj.2007.057133.


At TESTntel, safety is our top priority, regardless of the environment. Contact us today for a FREE COST ESTIMATE. Learn more about how TESTntel can help safeguard your environment against electrical hazards.

Learn more about TESTntel Field Services:


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