Tips & Advice

When do you use a Defibrillator?

When do you use a Defibrillator?

People often ask us at First Aid Accident and Emergency when it’s the right time to use a defibrillator on someone? 


In our first aid courses Gold Coast, we always make sure to teach you that if a person goes into cardiac arrest, their heart stops working properly, causing them to lose blood pressure and stop circulating blood. This is critical as brain and heart damage can happen within minutes.


At this point, the person will be unresponsive and not breathing effectively. However, make sure to check first! You don’t want to start CPR if they’re actually breathing. If they aren’t breathing properly, that’s when you grab the defibrillator.

DO NOT put a Defibrillator on first

Important! The patient needs CPR first as time is brain, CPR will circulate blood through the body and help to prevent tissue death in the heart and brain-“Time is Heart and Brain”- Scott Whimpey – Director FAAE.


Once CPR has been started, now is the time to apply the Defibrillator, making sure that First Aid and CPR  is administered. CPR must continue while the AED pads are applied to the patient. Much like a pool pump losing function, we need to prime the pump first before we start it up.


Studies show that the more we stop CPR and compressions in the first 10 minutes, the more brain and heart damage occurs, we need to minimise interruptions to compressions in the initial stages of resuscitation.

So when should a defibrillator be used?

Defibrillation should be used when someone goes into cardiac arrest, this is a serious medical emergency where the heart has stopped functioning properly. This happens from multiple conditions that can put the heart is in a life-threatening rhythm like ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT). In these conditions, the heart’s electrical activity becomes chaotic, and it can’t pump blood effectively to the rest of the body. The only thing that will revert the heart back into a normal pumping rhythm is a shock from a Defibrillator. 


Ventricular fibrillation (VF) is when the heart’s ventricles quiver uselessly instead of pumping blood. Pulseless ventricular tachycardia (VT) is when the heart beats too fast and ineffectively, leading to a lack of pulse. Both conditions mean the heart isn’t doing its job of circulating blood, which can quickly lead to death if not treated immediately.


In simpler terms, if someone’s not breathing then we know the heart is going to stop working out and deteriorate into fibrillation, this means it’s not pumping blood effectively, that’s when you start CPR and then place the defibrillator onto the patient. The defibrillator sends an electric shock through the heart to try to reset its rhythm and get it to beat normally again. It’s a crucial tool in these critical moments to save someone’s life.

Do you use a defibrillator if there is no breathing?

Yes, you absolutely should use a defibrillator if the patient is not breathing. If someone is not breathing, it means their heart is probably not beating effectively and is not pumping blood throughout their body. This is a critical situation because, without effective blood circulation, vital organs like the brain and lungs don’t get the oxygen they need, which can quickly lead to death.


In this scenario, we have a range of defibrillator bundles that are essential for survival. The device works by delivering an electric shock through the heart, which can help to reset the heart’s electrical activity. The goal is to stop the chaotic rhythm and allow the heart’s natural pacemaker to re-establish a normal rhythm. This process can be life-saving and is a key component of emergency medical response in cases of cardiac arrest.


So, in short, if someone is unresponsive and not breathing, that’s a clear sign that you need to strat CPR and use a defibrillator. Acting quickly with a defibrillator can significantly increase the person’s chances of survival by up to 80%.

How do you know if someone needs a defibrillator?

If someone suddenly collapses, isn’t responsive, and isn’t breathing normally, they will need a defibrillator. These signs indicate that the person could be experiencing cardiac arrest, a medical emergency where the heart stops pumping blood effectively. 


In addition to these signs, checking for danger and response crucial. If you determine that the person is not breathing and has no response, it’s a clear indication that their heart is not beating properly, and they need immediate help. This is where a defibrillator comes in.


Modern defibrillators are designed to be user-friendly, even for people with no medical training. When you open a defibrillator, you’ll usually find clear, step-by-step instructions on how to use it. Most defibrillators also come with voice prompts or visual aids to guide you through the process.


One of the most helpful features of many defibrillators is their ability to analyse the heart rhythm automatically. Once the device’s pads are placed on the person’s chest, the defibrillator can assess whether a shock is needed. If the heart is in a shockable rhythm, such as ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT), the defibrillator will prompt you to deliver a shock. If the heart is not in a shockable rhythm, the defibrillator will advise against delivering a shock and guide you on the next steps to take.


If someone collapses, isn’t responsive, isn’t breathing normally, they likely need a defibrillator. The device’s built-in instructions and rhythm analysis capabilities make it a vital tool in providing potentially life-saving assistance during a cardiac emergency.

Do you use a defibrillator when someone is breathing?

Nope, if someone is breathing normally, they don’t need a defibrillator. Breathing normally is a good sign that the heart is working well enough to keep oxygen flowing through the body. When someone is breathing, it generally means their heart is pumping blood effectively to vital organs, including the lungs, which allows them to take in oxygen and expel carbon dioxide.


Defibrillators are specifically designed for those critical moments when the heart stops beating or is in a dangerous, irregular rhythm that prevents it from pumping blood effectively. These conditions include sudden cardiac arrest with rhythms like ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT). In such cases, the heart’s electrical activity is so chaotic that it can’t maintain proper circulation, and a defibrillator is needed to deliver a shock to restore a normal heart rhythm.

When not to use a defibrillator?

Don’t use a defibrillator if the person is conscious and breathing normally. These signs indicate that the heart is functioning well enough to circulate blood and oxygen throughout the body. A defibrillator is not needed in such situations and could potentially cause harm if used inappropriately.


Additionally, there are specific scenarios where using a defibrillator could be dangerous. For example, avoid using a defibrillator on someone who is wet or lying in water. Water conducts electricity, and delivering a shock in these conditions could cause harm to both the person in need and the rescuer. Make sure the person’s chest is dry before applying the defibrillator pads.


Another important consideration is the age and size of the individual. Standard defibrillators are designed for use on adults and older children, but they are not suitable for very young children or infants. For these younger patients, a paediatric defibrillator or paediatric pads should be used to ensure the shock delivered is appropriate for their smaller size and developing heart.


Save the defibrillator for those life-and-death moments when the heart needs a reset, such as during sudden cardiac arrest when the person is unresponsive, not breathing normally, and has no pulse. Always ensure the environment and the condition of the person are safe for defibrillator use to avoid causing further harm. That’s what we teach in our first aid training gold coast courses, simply find a course online at FAAE.