How to Use a Workplace AED in an Emergency

A cardiac arrest can happen without warning, including in a familiar workplace surrounded by colleagues. Knowing how to use a workplace AED gives people the confidence to act while emergency help is on its way. The device is designed to guide the rescuer, but a quick, coordinated response from the team remains vital.

An AED, or automated external defibrillator, assesses a person’s heart rhythm and can advise or deliver a shock where appropriate. It does not replace calling 999 or giving CPR. Used alongside early CPR, it can give someone in cardiac arrest their best possible chance of survival.

Recognise cardiac arrest and act immediately

First, check that it is safe to approach. Look for hazards such as traffic, machinery, electricity, fire or an unsafe environment. Speak to the person and gently shake their shoulders. If they are unresponsive, open their airway and check for normal breathing.

Someone in cardiac arrest will be unconscious and either not breathing or not breathing normally. Agonal gasps can sound like irregular, laboured breathing, but they are not normal breaths. Do not spend too long checking. If there is any doubt, treat it as cardiac arrest.

Call 999 straight away, ideally using speakerphone so the emergency call handler can support you. Ask a colleague to collect the AED and bring the workplace first aid kit if available. If you are alone, call 999 before leaving the person to retrieve an AED, unless it is immediately within reach.

Start CPR as soon as possible. Place the heel of one hand in the centre of the chest, put your other hand on top and interlock your fingers. Press down firmly and quickly, aiming for a rate of 100 to 120 compressions per minute. Allow the chest to rise fully between compressions. If you are trained and willing, give two rescue breaths after every 30 compressions. If not, hands-only CPR is still far better than doing nothing.

How to use a workplace AED safely

As soon as the AED arrives, switch it on. Most units begin giving clear voice prompts as soon as the lid is opened or the power button is pressed. Follow those prompts, even if they differ slightly from what you remember from training.

Expose the person’s chest and dry it if it is wet. If there is a lot of chest hair and it prevents the pads sticking, use the razor commonly supplied in an AED kit to remove enough hair for the pads to adhere. Do not delay defibrillation trying to remove all chest hair.

Remove the backing from the adhesive pads and place them exactly as shown in the diagram on the pads. Usually, one pad goes high on the person’s right chest, below the collarbone. The second pad goes on the left side of the chest, below the armpit. The pads should not touch each other.

If the person has a visible implanted device, such as a pacemaker, avoid placing a pad directly over it. A small raised area below the collarbone may indicate one. Position the pad a few centimetres away instead. If you see a medication patch on the chest, remove it while wearing gloves if possible, wipe the area and then apply the pad.

Once the pads are attached, the AED will analyse the heart rhythm. This is the moment when everyone must stand clear. Say clearly, “Stand clear”, look around the person and make sure nobody is touching them. Even chest compressions must stop briefly during analysis.

If the AED advises a shock, check again that no one is in contact with the person, then press the flashing shock button if your model requires this. Some fully automatic AEDs deliver the shock themselves after a warning. The shock may cause the person’s muscles to jerk. This is expected.

Immediately restart CPR when prompted. Do not pause to look for signs of recovery unless the person starts breathing normally, moves purposefully or the AED tells you to stop. The device will continue to reassess the person at intervals and advise whether another shock is needed.

Keep the team organised around the casualty

The best workplace response is rarely one person working alone. While one colleague gives chest compressions, another can operate the AED, and another can manage the 999 call, meet the ambulance crew or direct them to the correct entrance. Clear roles reduce confusion at a stressful time.

If enough people are present, change the person doing compressions about every two minutes, ideally during an AED analysis period. CPR is physically demanding, and compression quality can fall quickly when a rescuer becomes tired. The change should be fast so there is as little interruption as possible.

Maintain the person’s dignity where you can, but do not let this delay treatment. Use a jacket, blanket or screen once pads are in place if appropriate. Ask unnecessary bystanders to move away, while keeping a colleague available to guide emergency services to the scene.

Children, pregnancy and other situations

The principles are the same for a child who is unresponsive and not breathing normally: call 999, start CPR and use an AED as soon as it is available. For children under eight years old, use paediatric pads or a paediatric setting if the AED provides one. If these are unavailable, standard adult pads can be used, ensuring they do not touch. On a small child, this may mean placing one pad on the chest and one on the back.

An AED can also be used on someone who is pregnant. The priority remains early CPR and defibrillation. Do not withhold treatment because of pregnancy.

In a wet environment, move the person away from standing water if it is safe to do so and dry their chest before applying pads. In cold weather, remove wet clothing from the chest as needed. The key consideration is that the pads must stick properly and nobody should be touching the casualty during analysis or shock delivery.

When to stop CPR and what happens next

Continue CPR and follow the AED prompts until ambulance clinicians take over, the person shows clear signs of life, or you are physically unable to continue. If the person begins breathing normally but remains unconscious, leave the pads attached, place them in the recovery position if safe to do so and monitor their breathing closely. The AED should remain switched on because their condition can change.

After the incident, preserve the AED as it is for the ambulance crew. The device records useful clinical information that may help the receiving team. A manager should arrange for the AED to be checked, cleaned where necessary and returned to service with replacement pads, a ready battery and any used items replenished.

There is also a people element. A cardiac arrest is distressing for colleagues, including those who did not provide direct care. Give staff an opportunity to talk through what happened, identify any support they may need and review the organisation’s emergency arrangements without blame.

Make AED readiness part of workplace planning

An AED is most useful when people know where it is, can reach it quickly and are prepared to use it. Keep it in a clearly marked, accessible location, with signage that visitors and new staff can understand. Consider whether access is available outside normal hours if lone workers, shift teams or members of the public are regularly on site.

Assign responsibility for regular checks. Pads have expiry dates, batteries need monitoring and the cabinet or alarm system should be tested in line with the manufacturer’s guidance. Your first aid needs assessment should consider the size of the premises, working patterns, hazards, visitor numbers and the time it may take for an ambulance to arrive.

AEDs are intentionally built for use by lay responders, so nobody should hesitate in an emergency because they lack clinical experience. However, practical AED and basic life support training helps staff recognise cardiac arrest sooner, deliver more effective CPR and work calmly as a team. For organisations, on-site training also allows staff to practise with the type of risks, spaces and response arrangements they actually have.

A workplace AED should never become a box on the wall that people hope they will not need. Make its location known, keep it ready and give colleagues the chance to practise. In an emergency, that preparation can turn hesitation into prompt, life-saving action.