Amazingly, 450,000 people each year are victims of massive heart at­tacks. And out of that number, approximately 250,000 die suddenly from this silent killer.¹That means that over half the people who experience a severe cardiac episode die. This sobering statistic puts in perspective that any one of our patients who walks through our doors for dental treatment may become the next casualty of a very deadly disease. And it only stands to reason that, as the population ages, the likelihood of a cardiac event occurring in our practices, though rare, may increase. Can you say that you and your practice are thoroughly trained if this unfortunate situation took place today? What is the chance that your patient would survive? Do you have the technology and training to treat the patient successfully until the paramedics arrive?

The American Heart Association (AHA) says that 10 minutes after a sudden cardiac arrest (SCA), a patient has only a 1% chance of survival. So, as a patient's first line of treatment, if you can provide only palliative care until the paramedics arrive and they are more than 5 minutes away, that patient's chances of survival are reduced. But there is a technology widely available, the automated external defibrillator (AED), that can be used by dental hygienists and trained office personnel to increase a patient's survival rate should such an event occur.

AEDs in the Workplace
To increase the chance of survival of a massive heart attack, AEDs can be placed in any dental practice or general workplace. Statistics from a recent study show that access to AEDs may increase that chance by up to 40%.² In addition, the AHA says that for every minute that passes before a victim of a SCA is defibrillated, the chance of survival drops by as much as 10%.³Those are sufficient reasons to have AEDs in your practice. A hygienist also must know how to recognize the signs of a SCA, when to activate the system, and how to do cardiopulmonary resuscitation (CPR). It's also important for hygienists, as well as the entire dental team, to receive formal training on the AED model owned by the practice. They will need to become familiar with the device and be able to successfully operate it in an emergency. The current AHA Basic Life Support for Health Care Providers (CPR certification) includes training and education on the use and implementation of AEDs.

Standard training will teach hygienists and team members how to avoid potentially hazardous situations. A general debate exists that AEDs provide a false sense of security to users because, if the proper emergency protocol is not followed (equipment maintained, calling 911 expeditiously, or incorrect usage), then the cardiac victim may not survive. However, a recent study proves otherwise.⁴ Therefore, a definitive emergency action plan and certified training are sound adjuncts to increase patient survival. Let's first understand what an AED is and how it works.

An AED is a portable electronic device that can audibly prompt and present on the monitor its detection of the need for and its ability to deliver an electric shock that will interrupt or stop the heart's dysrhythmic electrical activity.⁵ The shock will not start a dead heart, but it will stop certain lethal rhythms and give the heart a chance to spontaneously reestablish an effective rhythm on its own.⁶

An AED is easy to operate. It uses voice prompts to instruct the rescuer. Once the machine is turned on, the rescuer will be prompted to apply 2 electrodes provided with the AED to the victim's chest. Once applied, the AED will begin to monitor the victim's heart rhythm. If a "shockable" rhythm is detected, the machine will charge itself and instruct the rescuer to stand clear of the victim and to press the shock button.

A shockable rhythm, or ventricular defibrillation (VF), is an abnormal heart rhythm often seen during SCA. You may remember the term V.Fib from many of the emergency medicine shows on television. This rhythm is caused by an abnormal and very fast electrical activity in the heart. VF is chaotic and unorganized; the heart just quivers and cannot effectively pump blood. VF will be short lived and deteriorate to asystole (a flat line), if not treated promptly.

In short, a fast or irregular heartbeat hopefully can be regulated by the application of an electric shock produced by the AED so that a patient can survive long enough to receive more definitive treat­ment at the hospital. The typical AED will prompt the operator to continue CPR while the device continues to analyze the victim. The AED is not used instead of CPR but in addition to CPR. In my personal experience, AEDs are very accurate and easy to use. With a few hours of training, anyone can learn to operate an AED safely. Although there are many different brands of AEDs, all of them follow the same basic steps for use. The cost of an AED varies by manufacturer and model. Currently, an average price for a single AED unit is about $3000, but it can go as high as $4000. If your practice treats children, the AED you purchase will need to be suitable for pediatric use.

For teaching purposes, let's use an example that reflects what actually might happen in an average dental practice.

AEDs in Action
Mr. Jones sits in your hygiene chair to receive his 3-month prophylaxis. He was running about 10 minutes late and is winded when he sits in the chair. It's a hot July day, so the fact that he is sweating and breathing a bit heavy (from running in from the parking lot) doesn't appear strange or a reason for concern. You turn away to update his virtual record and the next thing you know Mr. Jones is slumped in the chair and not breathing. What do you do?

Assess Mr. Jones for responsiveness, "Mr. Jones, Mr. Jones, are you okay?" If unresponsive, lay Mr. Jones flat on his back, on the floor if you can get him there by yourself. Remember to assess the ABCs of CPR—airway, breathing, and circulation. Call for the AED and 911. Start CPR until the AED arrives. Then, either you or a team member turns on the AED and CPR is stopped. Apply the pads to Mr. Jones's bare chest. If there are specific instructions that need to be followed with your AED unit (you will know this from your training), proceed with them. If required, attach the electrodes to the unit and place the pads properly. No one should touch the patient after the pads are placed on his chest. The AED unit will tell you, either by voice or screen display, what to do. Follow the AED unit's prompts until the paramedics arrive.

The AED will analyze the patient's heart rhythm and may instruct you to shock the patient. The shock and analyze sequence will be repeated 3 times as long as a shockable rhythm is assessed. Continue to follow voice or screen prompts from the unit. At this point the AED may instruct you to perform 1 minute of CPR. Follow its instructions. Once emergency medical services arrive, let the paramedics take over the patient's care and provide them with the data from the AED as well as a copy of the patient's medical history. After the patient has left, thoroughly document all your data and information in the patient's chart while it is fresh in your mind. A follow-up phone call to the patient or family is also recommended.

That was a perfect case scenario with the equipment performing properly. What about equipment malfunction? What are the potential problems a hygienist could face when using an AED?

AEDs and Maintenance
Appropriately maintaining your in-office AED assures you that when the AED is needed, the unit will work to its best ability and you won't lose valuable treatment time trying to troubleshoot the device. Just like any other technology, equipment failure is a result of lack of maintenance or battery failure. Some AED units have rechargeable batteries for easy maintenance. Some AEDs perform automated daily or weekly tests of the electrical components, subsystems, and batteries to ensure readiness. Some offer a lithium battery with an extended shelf life for increased reliability.

The amount of maintenance needed is directly proportionate to how often the device is used. In some units, a weekly automated test checks the entire defibrillator device and its listing components, including the battery, the main processor, any stuck keys, the internal circuitry, and electrocardiogram acquisition. If a failure is detected in the weekly maintenance check, it will be identified on the display as well as by an audible sound and a "do not use" command that appears on the screen until the failure issue is resolved. If the unit has been used and more pads are required, remember to check that the new pads are compatible as soon as they arrive. Any used or expired kit supplies, such as gloves, razors, or pads, should be replaced immediately. During a medical emergency is not the time to discover that there is something missing or not operating properly. Just as a smoke detector can save lives only if it is maintained properly, only a properly working AED can save a patient's life.

Conclusion
AEDs not only have a place in the dental practice, but also in common public areas where they could save lives. Hygienists who are at the forefront of total health care for their patients should be trained and certified in the use of AEDs and CPR. No one knows when or if they are ever going to use this training and technology, but it takes just one patient in a serious cardiac event to understand the value and importance that it has in a dental practice.

"By failing to prepare, you are preparing to fail."

—Benjamin Franklin

References
1. Zheng ZJ, Croft JB, Giles WH, et al. Sudden cardiac death in the United States, 1989 to 1998. Circulation. 2001;104: 2158-2163.

2. Larsen MP, Eisenberg MS, Cummins RO, et al. Predicting survival from out-of-hospital cardiac arrest: a graphic model. Ann Emerg Med. 1993;22:1652-1658.

3. Health and fitness facilities need defibrillators. March 2002. American Heart Association Web site. Available at: www.americanheart.org/presenter.jhtml?identifier=3001034. Accessed May 31, 2006.

4. Stiell IG, Wells GA, Field B, et al. Advanced cardiac life support in out-of-hospital cardiac arrest. N Engl J Med. 2004;351: 647-656.

5. International Liaison Committee on Resuscitation. 2005 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations. Circulation. 2005;112(suppl I): III.1–III.136.

6. Larson MP, Eisenberg MS, Cummins RO. Predicting survival from out-of-hospital cardiac arrest: a graphic model. Ann Emerg Med. 1993;22:1652-1658