Defibrillators are one of the world’s most well-known medical devices. They’re frequently featured in medical movies, action films, and science-fiction video games, where they can revive the dead with an electrical jolt. They’re also one of the most sophisticated medical devices publicly available.
But how does a defibrillator work? Are they correctly portrayed in films and television, and are they effective? Let’s examine this incredible medical invention and discuss what it’s capable of.
What is a defibrillator used for?
A defibrillator is a type of medical device used to resuscitate a person in cardiac arrest. It resuscitates the person by restoring their normal heart function using a powerful surge of electricity.
The most typical cause of cardiac arrest is ventricular fibrillation. The heart’s electrical activity becomes erratic, causing its lower chambers to quiver irregularly—or ‘fibrillate.’ This is dangerous for the sufferer, as it prevents their heart from pumping blood properly around the body and into the brain. And people are usually dead within minutes without a constant flow of oxygenated blood to the brain.
The assumption that a defibrillator jump-starts the heart, as someone might jump-start a vehicle, is incorrect. Instead, the heart is still beating; it just does so ineffectively, which prevents blood flow. Rather than starting the heart, a defibrillator’s job is to stop it. The jolt of electricity freezes the heart for a moment, allowing the body to restart with a healthier rhythm. It’s not so much like giving a car a jump start as restarting a computer in the hope that this will repair the error.
In reality, defibrillators cannot help if a heart has stopped completely (known as asystole by medical professionals, or “flatline”). In such cases, knowing to do CPR is a necessity hence CPR certification can help and the aid of intravenous drugs provided by doctors.
Have defibrillators been around for a long time?
The notion of stopping and then restarting the heart with a surge of electricity has been around for many years. Swiss physiologists performing animal research at the end of the 19th century demonstrated that a small electrical shock could stop the heart of a dog, and a larger one could restart it. It wasn’t until decades later that this idea was used on humans. Many decades after an electrical engineer created the first defibrillator, it was tested on dogs.
A human was successfully revived using the procedure in 1947. The paddles were applied to the exposed heart during surgery to achieve this.
Closed-chest defibrillation—where the paddles are placed on the outside of the chest rather than directly on the heart during surgery—was first developed by a Soviet scientist in Kyrgyzstan in the early 1950s. Defibrillation became more practical for resuscitation as a result, and defibrillators of various commercial brands became increasingly popular starting in the 1950s.
In the early 1990s, portable defibrillators were not in wide usage in Australia, and they were rare in ambulances. But then, in 1990, Australian media baron Kerry Packer had a cardiac arrest. He was revived thanks to a portable defibrillator that was on the ambulance responding to the call. As a result, Packer donated a large sum of money to the New South Wales ambulance service on the condition that every ambulance was outfitted with a portable defibrillator unit. In Australia, the defibrillators are sometimes referred to as “Packer Whackers” in memory of this event.
What is an AED?
Defibrillators of several types are now available. Doctors and paramedics can use advanced hospital defibrillators to acquire detailed information and control the defibrillation process, but these devices are not for the general public. In the hands of an amateur, they might cause more problems than they solve.
AEDs, which can be used by laypeople, are a different thing. They are simple to operate, readily available, and, most importantly, it is unlikely that anyone would be injured by one.
What does the acronym AED stand for?
AED is an abbreviation for Automated External Defibrillator. Modern AEDs do much of the work for you, rather than you having to read detailed written instructions. An automated voice on most of the newer AEDs guides you through assessing the patient’s condition and connecting the AED properly.
Once an AED is connected to the patient, the majority of the work is finished. It estimates their heart rate and health indicators and makes a decision about whether defibrillation is required. Some models include a button that you press to jolt the patient (when advised by the machine), while others take care of that for you. When a shock is required, the machine loudly warns people to keep away before delivering it.
There are two major benefits to using this device. First, it will only zap patients when necessary (after warning everyone to keep away), lowering the risk of inaccuracy. Second, you will be relieved of pressure when you provide first aid because you will not have to make those choices yourself. You are more likely to attempt defibrillation if you know it is impossible to get it wrong.
It is becoming increasingly common for emergency services, police, and ambulances to carry AEDs as standard equipment. In addition to being available in public places such as community centres and shopping malls and as emergency medical equipment. Crucially, they’re also accessible as standard equipment on ambulances, police cars, and other emergency vehicles.
Who can use an AED?
A person who can read and follow directions can use an AED. Even children might be able to use one in an emergency with the help of the automated voice. There are no real limits on who may use an AED; however, the only time an AED will deliver a shock is if it is connected and detects a “shockable” heart rhythm. There is therefore little danger.
First aid training which includes how to properly use an AED is the best option when an AED is present. Even if someone has already undergone a CPR class or any of the more comprehensive first aid programs, having someone with prior AED experience can significantly reduce the time it takes to initiate it when someone has a cardiac arrest and time is of the essence.
When to use a defibrillator
The resuscitation process is well-established, and is often referred to by the abbreviation “DRSABCD”—or “Doctors ABCD” for something a bit more memorable. “Danger,” “Response,” “Send,” “Airway,” “Breathing,” “CPR,” and “Defibrillation” are each crucial to the resuscitation process.
When a person is both unconscious and without a pulse, the medical community advises that you should always assume they are suffering cardiac arrest. When this occurs, your first step should be to call 000 for assistance. Your next step should be to perform CPR—hopefully keeping the person alive for as long as possible. After that, you should perform defibrillation.
In addition to calling 000 and seeking out an AED, if more than one person is available, one of them should immediately begin CPR when a person has a cardiac arrest. Both CPR and defibrillation are essential to resuscitation. Without CPR, the individual’s brain would rapidly die of oxygen deprivation. However, the probability of resuscitating a cardiac arrest victim by performing CPR alone is very low – you’ll need more assistance and almost certainly defibrillation.
All of this is taught in a first aid CPR course.
You should also keep in mind that in most countries, including Australia, there is a legal defence known as the good Samaritan law. You may help in an emergency and make a genuine mistake without being sued or prosecuted (unless you are intoxicated or behaving recklessly). AEDs take away a lot of the difficult decisions from you. You do not need to worry about getting into legal difficulty for attempting to assist a victim if you hook them up to an AED.
How to use a defibrillator
Only AEDs are suitable for non-medical personnel to use. The other types of defibrillators are either highly sophisticated equipment that only medical personnel should have access to, or self-sufficient devices that are surgically implanted or worn.
AEDs are intended to be simple to use, so that non-experts may employ them in an emergency. AEDs are available in many forms and styles, but the directions (spoken or written by recorded voice) should be straightforward to follow.
Defibrillator sign / AED sign
AEDs have become a standard part of first aid kits in public places in recent years. Public first aid signage is well known, but AEDs have become widespread enough to necessitate their own signage, something that would be simple to recognise in a jam. The current standard is a white heart on a green background with lightning shooting through the centre, with a small cross in the upper right corner.
Typically, if you see a picture of a heart with a lightning bolt crossing it, an AED is nearby. However, in some areas, the heart may be red, or white on a red background (recalling the colours of the Red Cross), or the cross might be absent.
Defibrillator pad placement
The pads are generally accompanied by detailed instructions on how to position them, but as a general rule, you should position them so that the electrical current flows through the area of the heart. The pad should be placed on the right upper chest, above the right nipple and above the collarbone. The other pad should be positioned on the ribcage under the left breast, curving around the chest so that part of it is under the arm.
The pads should be positioned at 10:20 on the clock, as seen from the person’s chest, to result in the best outcome.
Be ready for the worst-case scenario
Certified CPR training takes only two hours to finish and costs less than a full tank of petrol. This is a professional requirement for many individuals, but CPR and AED training are also offered to the general public. The training provides CPR and AED fundamentals as well as hands-on practice with a dummy. If you want to learn how to help someone suffering a cardiac arrest, this is one of the best things you can do time- and money-wise.
