Everyone knows what a defibrillator (AED) is. They are used around the world as a first aid to respond to a sudden cardia arrest. Even an untrained, non-medical professional can use one to deliver first aid if required.
In Singapore, they are 9,203 AEDs!
What is a defibrillator used for?
A defibrillator is a device that sends an electrical shock or pulse to the heart in order to restore a normal rhythm. They are used to both prevent and correct abnormal heart rhythms (arrhythmia), and also restart a heart if it stops due to sudden cardiac arrest or other heart conditions.
The very first defibrillator was demonstrated in 1899 by Frédéric Batelli and Jean-Louis Prévost, two physiologists from the University of Geneva.
What are The Different Types of Defibrillators?
Manual External Defibrillator – MEDs are the most recognisable defibrillators thanks to TV, however, they can only be used by healthcare professionals and are primarily found in hospitals and ambulances. They are used in conjunction with an electrocardiogram (ECG), and the user needs to manually identify whether the patient requires a shock, and then what kind of voltage is required.
Automated External Defibrillator – AEDs use two paddles or sticky pads (electrodes) to deliver an electric shock to restore the natural heart rate in a similar way to MEDs. They were designed to allow anyone to use them in an emergency, and the automated computer analyses the heart rhythm to ascertain whether a shock is required—requiring little to no user input in order to save a patient’s life.
Implantable Cardioverter Defibrillator – ICDs are surgically placed within the chest cavity to check and correct arrhythmia. They work in a similar way to pacemakers, however, while pacemakers only deliver low-level shocks, ICD defibrillators are capable of delivering both low- and high-energy shocks.
Wearable Cardioverter Defibrillators – Like an ICD, an WCD can deliver both low- and high-energy shocks to the patient. In fact, the only difference is that these devices are attached to the skin with trailing wires connected to a unit that monitors your heart.
How Does an AED Defibrillator Work?
How does AED work?
AED defibrillators work by identifying arrhythmia and heart failure using a sophisticated computer and then delivering a shock to return the heart back to its natural rhythm. As suggested by the name, defibrillators stop fibrillation, the “trembling” that someone’s heart muscles may experience during cardiac arrest.
AEDs achieve this by passing an electric current through the heart, shocking it back into rhythm. The sticky pads on an AED form a circuit, allowing electricity to pass through the body without harming it and, when placed correctly, focussing that current directly on the heart.
How to Use an AED?
An AED consists of an analysis unit, or computer, and electrodes that are placed on the body which, when combined measure electrical signals from the heart. To help untrained individuals use AEDs correctly, there will be a diagram and set of instructions on the unit itself, telling you how to turn on the machine and begin the process. All clothing should be removed from the patient’s arms, chest, and abdomen before using the AED, and the pads should always be attached directly to the skin.
Once the pads are stuck to the body, the AED will begin to analyse the heart rhythm of the patient. If the process does not start automatically, then ensure you push the analyse button indicated on the machine. During this process, you should not touch or move the patient.
If the AED determines that a shock is required, you will be instructed to press the button on the unit. Newer units will only shock once, however, older units may shock up to three times, so be certain to read the instructions on the unit itself. More information on how to use an AED defibrillator can be found here.
Where to Find an AED
AEDs have revolutionised the healthcare sector, allowing untrained bystanders to provide lifesaving treatment to anyone who requires it. Today, you will find them located within large public places including:
Hospitals and other national institutes of health
When to Use A Defibrillator
AED defibrillators should be used when a patient is unresponsive and AFTER cardiopulmonary resuscitation (CPR) has been performed. This may be any condition where there is no pulse or response from the patient, however, it is also important to shake or otherwise try to wake up someone who is unresponsive before performing CPR or using an AED defibrillator.