Automated External Defibrillators (AED)

What is Defibrillation?
Ventricular fibrillation is a heart disease, in which the heart beats are irregular, leading to an heart attack. The irregular heart beat is the result of improper functioning of the heart ventricles. Heart ventricles pump the blood in the heart to other organs of the body, like the brain. The blood that is pumped, contains oxygen and other important nutrients required by the organs. Thus, if this blood is not pumped regularly to these organs, they stop functioning, and the person suffers from cardiac arrest (heart attack), which can be fatal.

Treatment for ventricular fibrillation involves defibrillation, in which an electric shock is given to the patient in order to restart the pumping of the heart. However, defibrillation should be administered immediately, after the cardiac arrest, as it does not prove to be useful if there is a delay. Many a times, it is not possible to give defibrillation immediately after the heart attack. If the patient is already in the hospital, the chances of survival increase, as defibrillation is possible without any delay. Every minute that goes without treatment, after a cardiac arrest due to ventricular fibrillation, reduces the patient's chances of survival by 10%. To ensure maximum chance of survival, the patient should be defibrillated within four minutes of the cardiac arrest.

What is Automated External Defibrillators (AED)?
Automated external defibrillators are electronic devices that sense the heart beat of a person and automatically apply an electric shock if irregularity is sensed. In 1980, Arch Diack, a surgeon at Portland, introduced this equipment. An AED, analyses the rhythm of the heart beats of a person and administers shock of an appropriate intensity if it finds that the heart is not beating properly. AED is a user-friendly device and is easy to operate. When one operates an AED, first the AED checks for the heart rhythm of the patient, then it gives a signal that informs the user whether an electrical shock is needed or not. When the user responds to the signal from the AED, an electrical signal is passed to the patient's chest through the electrode pads of the AED.

Who can operate Automated External Defibrillators (AED)?
Usually, people trained for Cardiopulmonary Resuscitation (CPR) are also trained for AED. People without a medical background can also be trained for operating AED. Training for operating Automated External Defibrillators (AED) is generally given to policemen, flight attendants and security guards.

Where are Automated External Defibrillators (AED) installed?
Initially, AEDs were installed in ambulances and they helped reduce deaths due to heart attacks outside hospital. However, it was necessary to place AEDs in maximum places because every minute after a cardiac arrest is crucial in saving a life. Hence, AEDs are now installed in public places as well. Policemen, flight attendants, fire rescuers are given training for operating ADE. AEDs are fairly easy to operate and hence, the concept of PAD (Public Access Defibrillators) came up. Training for ADE takes quite a less amount of time, i.e. 4 hours. Training is recommended to be given for maximum people in order to increase the survival rate.

How to operate Automated External Defibrillators (AED)>
AEDs are manufactured by different companies, all having the same working principle. Before AED is used, the steps of CPR should be performed. AED is a computerized device. Voice commands from the ADE will act as a guide during the complete process. When you turn the device 'ON', it will ask you to place the electrodes on the patient's bare chest. AED will begin the examination of the heart beats and show an ECG (Electro cardiogram graph). For an accurate ECG, it is recommended that you should not touch the patient during the examination. The AED will then give a signal that will inform you whether an electric shock needs to be given or not. If the shock is to be given, AED charges itself and asks you to press the appropriate button. It will ask you to repeat CPR after an electric shock has been given.

Use of AED has increased with time, as they have helped save many lives from cardiac arrest. Time is the most vital factor when using AED. It is important to remember that if AED is administered after a long time has elapsed, AED may not prove helpful. Thus, AEDs are installed at many places, so that the patients suffering from any heart disease can be treated as soon as possible. However, contrary to a common misconception, AED is not a replacement for CPR, but AED along with CPR is an effective treatment that can start normal heart beating. Awareness about AED is important, and hence a huge number of people are trained every year, to operate AED.