Defibrillation is a common treatment for life-threatening cardiac arrhythmias, ventricular fibrillation (where the heart is in spasm but not pumping blood normally) and pulseless ventricular tachycardia (essentially where the heart has stopped functioning). Defibrillation consists of delivering a therapeutic dose of electrical energy to the affected heart with a device called a defibrillator. This depolarizes a critical mass of the heart muscle, terminates the arrhythmia, and allows normal sinus rhythm to be reestablished by the body's natural pacemaker, in the senatorial node of the heart.
Whilst medical technology has now allowed some Defibrillators to be implanted within patients at risk of cardiac arrhythmias, the most commonly observed defibrillators are external. External defibrillators take two standard forms. Firstly manual defibrillators, these are for professional use only and common in hospital ‘crash’ units and onboard Ambulances. They are a common sight in medical television programs such as Casualty, where to ‘paddles’ are placed onto the patient’s chest and a shock applied. An example of this type of defibrillator is the Physio-Control Lifepak 15, retailed by First Aid Warehouse for £18,000 + VAT.
Defibrillators are not just available for professional use though. Some external units, known as automated external defibrillators (AEDs), automate the diagnosis of treatable rhythms, meaning that almost everyone is able to use them successfully with little or in some cases no First Aid Training at all. As a result of the diagnosis, a ‘shock’ is only delivered to patients who need to receive such treatment, it’s almost impossible to use an AED to shock a patient who did not require such treatment. The location of public access AEDs generally takes in to account where large groups of people gather, and the risk category associated with these people, to ascertain whether the risk of a sudden cardiac arrest incident is high. For example, a school is a particularly low risk category (as children very rarely enter heart rhythms such as VF (Ventricular Fibrillation) or VT (Ventricular Tachycardia), being generally young and fit. On the other hand, a cruise ship or golf club with a high ratio of males over 50 is a very high risk environment.
There are 2 types of AEDs: Fully Automated and Semi Automated. Most AEDs are semi automated. A semi automated AED automatically diagnoses heart rhythms and determines if a shock is necessary. If a shock is advised, the user must then push a button to administer the shock. A fully automated AED automatically diagnoses the heart rhythm and advises the user to stand back while the shock is automatically given. Also, some types of AEDs come with advanced features, such as a manual override or an ECG display.
In order to make them highly visible, public access AEDs often are brightly coloured, and are mounted in protective cases near the entrance of a building. When these protective cases are opened, and the defibrillator removed, some will sound a buzzer to alert nearby staff to their removal but do not necessarily summon emergency services. All trained AED operators should also know to phone for an ambulance when sending for or using an AED, as the patient will be unconscious, which always requires ambulance attendance.
Whilst training is not always needed in order for someone to properly use an AED, most local voluntary groups such as St John Ambulance, The British Red Cross and The British Heart Foundation, run free tutorials to educate the public about their use. The First Aid Training is simple and suitable for everyone, regardless of previous first aid knowledge.
First Aid Warehouse is one of the UK’s leading Medical Suppliers which stock a range of products including Cardiac Training and Laerdal Manikins.
