As public awareness of solutions for SCA rescue grows, the devices, hospital defibrillator and public AED, used to defibrillate patients in sudden cardiac arrest (SCA), are becoming better known. Though both devices are dedicated to restoring a normal heartbeat by sending electrical impulses or shocks to the heart of people suffering from a serious heart problem called ventricular fibrillation, they are not the same. Then what are the differences between hospital defibrillator and public AED, and why should they be distinguished?
Differences between Hospital Defibrillator and Public AED
The hospital defibrillator in this context refers to a specialized manual external defibrillator (MED) used in hospitals to restore a patient's normal heart rate. It is designed for trained medical personnel to detect different heart problems and treat them appropriately, as it requires doctors to assess how much shock energy should be delivered to the patient and decide when and how often to administer the shock. This is what is defined as manual defibrillation.
A public AED, on the other hand, is an SCA rescue device that anyone can access, designed for non-medical personnel outside the hospital. Some are equipped with voice prompts, pictorial instructions, and a buzzer to indicate when the user should administer an AED shock. The AED equipment is typically wall-mounted with a special AED box and placed in public places outside hospitals, such as airports, stations, office buildings, stadiums, etc., to provide the fastest response time for out-of-hospital SCA rescue. They are fundamentally different in appearance, operation, and functionality.
• Appearance
In terms of appearance, most people think of the manual defibrillator in hospitals as two hand paddles connected by wires to a larger monitor. They are typically used in acute hospital settings, have oversized dimensions, and are stored in a crash cart. While a public AED is a portable device the size of a regular lady’s handbag and is very light in weight. A complete portable AED kit includes an AED machine, a pair of AED replacement pads, and a battery. In use, the public AED is powered by the battery without the need for socket power; thus, it is the perfect solution for out-of-hospital SCA.
• Operation
In terms of operation, a hospital defibrillator is more complicated than a public AED. Doctor has to turn on the device at first, then switch to the correct treatment mode, since most of the manual external defibrillators are designed with several treatment modes. After that, it’s time to select the proper energy level based on clinical condition, press the charge button and deliver the shock by pressing the shock button. Even in words, the whole process is not easy, especially for those people who haven’t got any professional training before. Public AED, on the other hand, is relatively foolproof to operate because essentially every public AED on the market is equipped with comprehensive automated voice prompts explaining subsequent steps. During operation, the public AED informs you how to place the pads, when to perform CPR, when to administer an AED shock and when you should back off. Moreover, public AEDs deliver AED shocks at a pre-set energy of 200 joules each time, without the need for responder tuning. These are extremely important features of a public AED because it ensures that everyone is available to help in an emergency.
For public AEDs, there are fully automatic AED and semi-automatic AED. A fully automatic external defibrillator simply requires the responder to attach the AED pads to the correct location (as for the attachment method, the AED machine will have voice guidance, and some AED brands, such as Mindray, also have detailed diagrams on the AED pads). It will automatically analyze the patient's heart rate and deliver the AED shock automatically after a shock indicator is given under the right condition. In the case of a semi-automatic external defibrillator, it is necessary for the responder to press the shock button to deliver an AED shock.
• Functionality
In terms of functionality, a hospital defibrillator can not only deliver the shock as an AED, but also has functions that a public AED does not support, such as pacing (providing electrical pulses to stimulate the heart to contract), synchronized cardioversion and patient monitoring.
While defibrillators used in professional medical settings rely on the understanding and knowledge of physicians to defibrillate patients promptly, the intervention of public AED devices becomes necessary in public places where SCA occurs due to the lack of obvious symptoms and guidance from professional medical personnel. However, in many areas, the survival rate of out-of-hospital SCA remains low due to the lack of public AEDs or improper use of AED devices that cause patients to miss the best time for rescue. Therefore, it is of great significance to further emphasize the importance of public AED equipment and the use of an AED device.
How to Use an AED Device?
Studies have shown that the survival rate of SCA patients increases 2.62 times when bystanders are able to effectively use public AEDs.[1] Managers of communities, office buildings, gyms, stadiums, and other places with a high incidence of SCA should take on the responsibility of popularizing the use of public AED equipment in addition to actively deploying AED devices to improve the survival rate of out-of-hospital SCA.
The use of AED equipment is divided into the following steps:
- When the AED device is available, responders should immediately turn on the machine and check whether the machine, AED replacement pads, and battery are in normal condition. If normal, then follow the voice prompts to continue operation; otherwise, immediately replace the AED device with a new one.
- Remove the patient's clothing (dry the chest or remove chest hair if necessary) and place the AED pads in the correct position according to the voice or picture instructions. Place one AED pad on the upper right side of the chest and place the other AED pad on the lower left side of the chest, a few inches below the left armpit.
- When the AED equipment senses the correct position of the AED pads, it will automatically analyze the heart rhythm.
- If the AED device believes that the conditions are right to deliver an electric shock, it will issue a "defibrillate" command and beep. Make sure that no one is touching the patient after the command. A fully automatic external defibrillator automatically delivers a shock, while a semi-automatic external defibrillator requires the responder to press the shock button before a shock is delivered.
- After the shock delivery, or if an AED shock is not recommended, perform CPR for two minutes until the patient gives a response.
For the public, they are different from professional health care professionals who have a thorough grasp of the use of medical equipment，so public AED devices should ideally be smart and user-friendly enough. As is the case with the Mindray AED devices, paired with the ResQNaviTM patented technology that can give different feedback mechanisms based on the user's level of proficiency. For newcomers, Mindray AED will provide more detailed voice guidance and picture explanations, while for skilled users, Mindray AED will improve the speed and simplify the details of voice guidance accordingly. Not only that, with the CPR feedback mechanism, Mindray AED can provide continuous encouragement for responders to perform CPR for more productive lifesaving results.
It is becoming increasingly evident that public AEDs are moving toward greater simplicity, portability, and intelligence than hospital defibrillators. Given that portable public AEDs are effective in saving lives and improving survival rates for out-of-hospital SCA, is your workplace, community, or local areas already equipped with an AED device? And if not, why not? Consider installing a user-friendly device like Mindray AED at your location so that you are prepared, too!
Reference:
[1] Impact of Bystander Automated External Defibrillator Use on Survival and Functional Outcomes in Shockable Observed Public Cardiac Arrests. AHA Journal, Circulation. May 15, 2018, Vol 137, Issue 20. Pages 2104–2113. Available at: https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.117.030700 (Accessed: 20 December 2021)
