Healthcare technology management experts participating in this month’s roundtable article on defibrillators include ReNew Biomedical Director of Biomedical Services Neil Davidson, ProHealth Care Senior Biomedical Engineer Michael Howell, Coro Medical’s Kyle Kelly and Fluke Biomedical Global Training Manager Jerry Zion.
TechNation asked these industry insiders to share feedback regarding the basic functions every automated external defibrillator (AED) should have, what to look for when purchasing these devices, tips regarding maintenance and more.
Q: What are the basic functions or features every automated external defibrillator (AED) should have?
Davidson: First and foremost, every AED should be biphasic. Even though it’s 2021, we still come across monophasic AEDs and always recommend an upgrade. Knowing whether your AED is semi-automatic or fully automatic is essential, as the semi-automatic will automatically charge but requires the user to press a button to deliver the shock. By contrast, fully automatic AEDs will charge and deliver the shock without needing the user’s go-ahead. Also, some newer model AEDs have three-lead ECG capabilities, showing the ALS or advanced user a visual display to monitor the patient’s heart rhythm.
Howell: Every AED should have automated voice prompts, tones and images that guide the user while they’re operating the device. The ability to display the waveform is important. That way the impaired person’s arrhythmia can be seen. There should be a status indicator to show the condition of the AED. For example, Zoll uses a green check mark to show that nothing is wrong and a red X if there is an issue with the AED.
Kelly: There are several functions and features that every AED should have, but it really depends on where the AED is placed and who will be using it. The first thing you will want to consider is semi-automatic versus fully auto functionality. Are you comfortable pressing the shock button if prompted, or would you prefer that the AED analyze and deliver a shock on its own? Secondly, CPR Feedback is an invaluable feature which guides you to perform high-quality compressions via voice and/or text prompts on the AED. Depending on the device, the AED will correct you on rate, depth and release/recoil. Lastly, pediatric capability is another function that is a must. Some devices require pediatric pads which reduce the amount of joules in the delivered shock; some devices use the same pads as adults, but they have a button for pediatric mode or use a “key” that reduces the joules when inserted.
Zion: IEC-60601-2-4 and AAMI/ANSI DF80 provide the functionality for minimum performance and safety of automatic external defibrillators (AEDs). Among these are the ability for the device to distinguish among shockable and non-shockable heart rhythms, the ability to identify when a shockable arrhythmia has converted to a more normal rhythm, the ability to increase output delivery from an initial level to one or more increased levels (when no rhythm conversion has been achieved), the CPR coaching cycle between rhythm assessments and an internal quality assurance self-check. Though the internal quality assurance health check may not be the total appropriate assessment to keep failure rates under control, they are an important function of the AED and collect a wealth of information about internal processes.
Q: What types of checks and regular maintenance do defibrillators/AEDs require?
Davidson: At a minimum, all defibrillators and AEDs require annual maintenance. Every device has a service manual that sets testing guidelines from A to Z. The scope of testing needed can vary greatly depending on the device’s complexity, but all manufacturers require yearly upkeep and preventative maintenance checks. The complete operational analysis covers the unit’s buttons, printer, alarm, battery, power supply and testing all relevant parameters. Additionally, all units require a visual inspection to ensure safety for both the patient and the user. The final step is to perform calibrations that generally cover pacing and defibrillation, specifically on ALS units on a Crash Cart or in EMS use. Ensuring that both of these functions are accurate is vital when it comes to saving a life.
Howell: Defibrillators/AEDs require output delivery checks for energy output accuracy, gain checks to verify waveform amplitude and battery checks. Each manufacturer may require specific equipment to verify the energy delivery and create the correct type/size of waveform. Battery checks may require you to measure voltage, while others will have capacity indicators and will only need a visual check. In either case, the manufacturer will recommend a replacement time.
Kelly: The AED battery and electrode pads are items that eventually will need replacing. Batteries can last 60 months or more and electrode pads range between 18-60 months depending on the model. However, all devices are different, and you should confirm expiration dates on all disposables. Most devices have audible “chirps” that call attention to the device when it needs to be serviced, and all AEDs have visual indicators that show you the status of the AED. All AEDs run self checks on predetermined intervals that confirm the readiness. Currently, there is no regular maintenance or calibration required.
Zion: There are two categories of defibrillator: Advanced Cardiac Life Support (ACLS) and AEDs. Each has functionality that differs from the other. There are also different periodic checks, some of which are done by the nursing staff, and others (e.g., the semi-annual/twice per year testing) which is done by biomeds using test instruments. Nursing staff check the supplies and accessories to make sure they are up-to-date, not out-of-date, and high-level functions like the ability to safely discharge unneeded energy internal to the device. Biomeds have the responsibility to test to the manufacturer’s model-specific service manual test procedure, which runs through all features and functionality of the device, including those special AED functions discussed in the earlier question. Biomeds should also check pacemaker functionality (if applicable) and ensure that impedance sensing circuitry is performing as it should. Batteries are a common failure mode for AEDs, so they should be checked regularly for charge level and corrosion. The list of all these tests is quite long in order to ensure that the life saving device is safe and effective for clinical use. We have several webinars on this topic that we encourage all interested persons to view.
Q: What are the most important things to look for in a defibrillator/AED?
Davidson: The most important thing to look for in a defibrillator is whether it was correctly tested and when the last date of service was. Next, know what capabilities and parameters your defib has. For instance, most hospital crash cart defibs are 3-lead with pacing for advanced users and the AED/Analyze functions on board are used by BLS staff to revive a patient. However, ambulance paramedics prefer defibrillators with the latest technology and monitoring capabilities including Bluetooth and Wi-Fi with 12-lead Interpretive ECG, SpO2, Et-CO2, NiBP, Non-Invasive Pacing and AED/Analyze function. These communication options allow them to send the 12-lead ECG data ahead to providers at the hospital in real time. With many defibrillators on the market, select one for the proper job and correct provider.
Howell: The defibrillator/AED should be easy to use. The automated voice should be clear and have understandable instructions. Reason being, you want anyone to be able to use it. It definitely needs to have a reliable battery capacity. You can’t recharge them like regular defibrillators. The battery usually needs to be replaced every 3-5 years.
Kelly: The most important things to look for in an AED are determined by your department’s needs. Are you on the go? You’ll want to consider a lightweight option. Will this be thrown around in a truck or get banged up? A durable device that can withstand a beating is the best option for you. Are you able to manage the AED and keep track of the status indicator? If not, Wi-Fi capability is a plus. For manual defibrillators, you’ll have several things to consider like functionality (SpO2, 3/12-lead, Bluetooth, etc.) and durability.
Zion: The most important things to look for in a defibrillator/AED are the ability to recognize shockable versus non-shockable heart rhythms, an easy to use human interface, high reliability (low failure rate) and few manufacturer-initiated corrective actions or U.S. FDA recalls.
Q: How can a HTM professional extend the life of defibrillators/AEDs?
Davidson: HTM professionals can extend their defibrillators’ lives by following the service manual from front to back. The manual covers cleaning, testing and calibrating. At Renew Biomedical, we like to take this a step further and first open the device to replace the internal coin cell, which typically holds the time and date, but in some cases also maintains the device’s software settings. Inside, we verify the components’ integrity to include Main System PCB, Therapy PCB, high voltage modules, capacitor, system interconnect PCB and ensure the ribbon cables are correctly plugged in and secure. Once reassembled, we perform preventive maintenance (PM), referred to as planned or scheduled maintenance in the service manual.
Howell: Generally, defibrillators are very reliable. The best way to make them last is checking for error codes, keeping an eye on the service light or service indicator. You should replace the battery as often as the manufacturer requires. Finally, make sure that there isn’t any physical damage.
Kelly: The best thing you can do to extend the life of the device would be to keep it out of direct sunlight and out of extreme temperatures. Limiting the number of self-checks to once a week will help maintain battery longevity. Lastly, keeping the device clean will also protect from possible corrosion of the internal components.
Zion: Perform the periodic testing and justify by independent, objective evidence that the device remains safe and effective for clinical use. Follow the manufacturer’s service manual test procedure. Doing so adheres to medical device quality assurance best practices. We also have webinars available on these topics.
Q: What else should TechNation readers know about defibrillators/AEDs?
Davidson: To all readers out there, you can’t test your defibrillator often enough. Implementation of daily, weekly and monthly checks can ensure your defibrillator will function properly when needed most! A simple user test is as easy as powering on the device, verifying the AC power indicator is on, making sure your pads are ready and within expiration date, and running the self-test and user test that takes just seconds. Remember to change pads and batteries regularly, per the operator’s manual; this can and will save a life.
Howell: Unlike the standard defibrillator, AEDs are made so that virtually anyone can use them. Therefore, you will see them in malls, churches, restaurants and other public facilities. They can be used on children but, there is a minimal weight. Because there isn’t a manual mode. AEDs only will allow a patient to be shocked when “shock advised” is stated. So, if the person has a normal sinus rhythm or if there is no sinus rhythm, the AED will not shock.
Kelly: To the average person, it may seem overwhelming to think about using a medical device on another person. You may be surprised to learn that an AED is very easy to use, and anyone can do so under any circumstance. An AED will give you verbal step-by-step instructions. As soon as an AED is turned on, the device provides clear instructions on how to begin, reminds you to call 911 and will guide you through every step of the rescue. The AED will analyze to determine if there is a shockable rhythm and will only send a shock to the person if one is detected. The device will only shock if it is needed, so there is no need to worry of hurting the person by using an AED. Providing life-saving treatment to a co-worker, loved one or stranger that has only minutes before permanent damage or death occurs is exactly what the AED was designed for.
Zion: The 50-ohm test load in standard defibrillator analyzers may not be enough to evaluate innovative functionality meant to ensure that what you set (for energy delivery) is what you get (no matter the tissue impedance across which it must be delivered). Choose the right tools to perform the necessary testing to find problems while they are small and cost effective to fix. This helps ensure that the defibrillator will work properly for your biggest or smallest, oldest or youngest patient.
