What is a defibrillator?
A defibrillator (also known as a defib unit) is a piece of equipment designed to treat patients with life threatening cardiac arrhythmias through the application of therapeutic electrical currents. The electrical charges applied (by the defibrillator) to the patient’s body force the heart to regain a 'normal' rhythm.
AEDs (Automated External Defibrillators) automate the steps for diagnosing and treating the hearts rhythm, helping little trained users of the device to confidently and safely treat the patient. The AED controls the administering of the electric charge to successfully resuscitate the patient.
How does a defibrillator work?
Defibrillators are designed to administer a therapeutic electrical charge to a patient to stabilise the rhythm of their heart. An AED (Automated External Defibrillator) firstly instructs the carer to place the pads on the patient. It then diagnoses whether the patient requires de-fibrillation by monitoring the hearts rhythm and if necessary, controls the strength of the electrical charge administered to the patient.
Semi-automatic AEDs are designed for users who have received AED training. Semi-automatic units will detect when a shock is required and alert the user who will then make the decision on whether or not the shock should be issued. Semi-automatic units also have a pacemaker function for occasions where the victim's heart rate is too slow (bradycardia).
Fully-automatic AEDs will administer the shock automatically after the machine has tested the patient. A lesser degree of training is required for this type of AED.
Who is responsible for the maintenance of an AED?
There is no legal obligation for a defibrillator to be regularly serviced. Many defibrillators carry out automatic self tests on a daily, weekly and monthly basis and have a visual indicator if there is a problem with the unit. Defibrillator batteries and electrode pads have a stand-by lifespan, and it is the Health and Safety Manager's responsibility to ensure that these components are replaced before the time scale is exceeded, and that the battery remains fully charged (if rechargeable) ready for an emergency. A defibrillator does not have a set lifespan. As long as the battery and electrode pads are replaced when needed, the defibrillator will continue working past its warranty period.
Although it is highly recommended, it is no longer compulsory for people to be trained before using a defibrillator and for first aiders to attend regular refresher courses on how to operate them.