ACOEM Occupational AED Guidelines
On November 13, 2000, President Clinton signed into law H.R. 2498, the Cardiac Arrest Survival Act (CASA), designed to expand the availability of automated external defibrillators (AEDs) in public settings. The new legislation requires the Secretary of the Department of Health and Human Services (HHS) to establish guidelines for the placement of AEDs in buildings owned or leased by the federal government.
The American College of Occupational and Environmental Medicine (ACOEM), while applauding this legislation urges the consideration of AEDs in selected workplaces, beyond the scope of federal buildings. The College has thus developed this guideline to increase the awareness of the value of AEDs and has presented recommendations to encourage and provide guidance on their use in the workplace. This guideline reviews the following topics: (1) epidemiology, morbidity, and mortality of cardiovascular diseases in the workplace; (2) the “chain of survival” paradigm; (3) history and descriptions of AEDs; (4) standard-of-care interventions and guidelines; (5) public-access defibrillation and federal initiatives; and (6) recommendations for establishing and managing a workplace AED program.
Epidemiology, Morbidity and Mortality
Heart disease is a significant public health concern. The American Heart Association estimates that in 1997 alone, 7,700,000 Americans experienced myocardial infarctions and 6,300,000 suffered from angina pectoris.1
During 1996, reported incidence rates in the United States for the combination of ischemic heart disease and heart rhythm disorders, including tachycardia and other unspecified rhythm disorders, were 78.1 per 1000 persons.2 Among working-age adults, incidence rates were 39.3 per 1000 persons for those 18-44 years, and 116.4 per 1000 persons for those 45-64 years.3
The Occupational Safety and Health Administration reported that from 1991-1993, 15% of workplace deaths were due to sudden cardiac arrest (SCA)4 Data collected from Calgary, Alberta, from 1992-1996, revealed that 13% of cardiac arrest deaths occurred in public or commercial sites, 5% were in large buildings (> 250 people), and 8% in small buildings (< 250 people).5 Data reported from a 1990-1994 Seattle area retrospective cohort study found 16% of cardiac arrests occurred in public places.6
SCA and the Chain of Survival
There are several electrical abnormalities that result in SCA, but the majority of deaths begin with an initial rhythm of ventricular fibrillation (VF).7-9 If VF is not treated quickly, this potentially reversible dysrhythmia typically degenerates into asystole, which is generally fatal.10 The standard medical protocol to correct VF and pulseless ventricular tachycardia (VT) is the application of electric shock with a controlled dose and duration of energy. If the initial shocks fail to convert the rhythm, advanced cardiac life support (ACLS) protocols call for a series of medications to be given in a medication-shock, medication-shock sequence.
Factors contributing to out-of-hospital survival following SCA have been described primarily in terms of the time-related “chain of survival” paradigm.11 The four links of the chain include: (1) early recognition and call for emergency medical services; (2) initiation of basic life support CPR; (3) defibrillation; and (4) advanced cardiac life support (ACLS) drug intervention. Survival depends on the availability of the links – although more advanced applications may jump ahead of lesser ones. For example, if community emergency medical service (EMS) responders – or medical providers at the scene – are not qualified or prepared to deliver ACLS, this link may not be available until the patient arrives at a medical center. If a workplace has basic life support providers equipped with an AED and an ACLS-level medical department, the timing between these links may be shorter.
Without intervention, survival following SCA decreases rapidly. Several studies have reported that for each minute of untreated cardiac arrest, the probability of successful rhythm conversion decreases by 7% to 10%, producing an equivalent per-minute-death rate.12,13Conversely, survival rates as high as 90% have been reported when the collapse-to-defibrillation time is within one minute.14-16 To better define each the contribution of each link in the “chain of survival,” data were examined between 1976 and 1991 in Seattle.17 A best fit model demonstrated a fit with the following equation:
Survival rate = 67% at collapse – 2.3% per minute to CPR – 1.1% per minute to defibrillation – 2.1% per minute to ACLS
As noted by the authors:
“The regression constant, 67%, represents the probability of survival in the hypothetical situation in which all treatments are delivered immediately on collapse to patients with prehospital cardiac arrest … With delays in CPR, defibrillatory shock, and definitive care, the magnitude of the decline in survival rate per minute is the sum of the three coefficients (-2.2%, -1.1%, -2.1%), or –5.5%.”17
It is clear that while some variation in the time/survival equation exists, the sooner VF is treated, the more likely a positive outcome. Moreover, data show that some adults in VF remain neurologically intact even when defibrillation is delayed for up to 10 minutes after arrest if CPR is provided.14,18,19 Indeed, performing CPR prior to defibrillation seems to prolong VF, which may “buy time” until an AED can convert the rhythm, thereby helping to preserve heart and brain function.17,20 CPR without electric therapy may sustain a patient in VF for a short time but only rarely restores an organized rhythm. As return of an adequate perfusing rhythm requires immediate application of the combination of CPR, defibrillation, and ACLS within a few minutes of arrest, establishing controls to permit smooth and fast support of the chain of survival enhances the probability of survival.
History and Descriptions of AED
While conventional, manual external defibrillators have been used in clinical settings and some emergency medical services (EMS) for nearly 50 years, the automated external defibrillator (AED) did not make its debut until 1979.21 Utilizing solid-state circuitry and micro-computer technologies, the modern AED identifies VF, voice prompts a user to prepare to deliver a shock, and when a button is pushed, delivers the electric charge. Many studies have shown that AEDs are nearly error-free22 and effective when used by hospital-wide resuscitation teams,23 EMTs,24-26 fire department rescuers,23 police officers,27,28 and non-medical, first-aid responders in the workplace.29-31 In the last decade, there has been a remarkable increase in the placement and use of AEDs. Reasons include the accumulation of additional clinical studies confirming the safety, efficacy, and accuracy of these devices;32-34 the development of a smaller and lighter batteries and cases (less than 5 lbs); and the easy-to-follow audio prompt instructions.
Types of AEDs
The term “AED” commonly refers to any device that analyzes cardiac rhythm and prompts a user to deliver a shock when necessary. These devices only require a user to attach pads to a patient’s chest, turn the device on, and follow audio instructions. They do not require any decision-making or interpretation of symptoms. Most AEDs, therefore, are “automated” in that they analyze and advise. “Fully automated” or “automatic” external defibrillators that deliver a shock without a prompt to press a shock button are available for special situations.
Analysis of Rhythms
AEDs utilize microprocessors to analyze several characteristics of the surface ECG signal. Wave frequency, amplitude, and some integrated features such as slope or morphology are identified and compared to preset values. In an unresponsive, non-breathing, pulseless patient, an AED will advise shocks for monomorphic and polymorphic ventricular tachycardia (VT), supraventricular tachycardia (SVT), or VF. When shock advisories have been reported for patients with perfusing ventricular or supraventricular arrhythmias,35 these were confirmed as due to interpretation, reporting and response errors of operators not device, errors.36
An AED should be used for management of full cardiac arrest, and only when all movement is absent. Any patient movement (e.g., patient transport, seizures, or agonal respirations) can disrupt the ability of the device to complete rhythm analysis. Occasional errors have also been reported due to failure to deliver shocks in cases of extremely fine or course VF,37 incomplete cycles of analysis,24,31 failure to follow the AED manufacturer’s instructions,34 and conflicts with an implanted defibrillator.38
Waveforms and Energy Levels
Although there is no clear relationship between adult body size and energy requirements, the dose and duration of AED energy must be appropriate. When energy or current is too high, there is a risk of cardiac injury and myocardial infarction; when too low, the shock may fail to terminate VF or other arrhythmias.39-41
Modern AEDs provide one of two categories of waveforms: monophasic or biphasic. Monophasic waveforms provide current flows in a single direction (polarity). When the rate at which the pulse falls to zero is gradual, they are referred to as monophasic damped sinusoidal (MDS). When the rate is instantaneous, they are called monophasic truncated exponential (MTE). Biphasic waveform defibrillators deliver a sequence of two pulses in which the second is of opposite polarity to the first. While biphasic damped sinusoidal (BDS) and biphasic truncated exponential (BTE) are both technically possible, current manufacturers only market BTE devices. To maximize the success of the shock, monophasic AEDs use an escalating energy sequence. The recommended energy for the first shock is 200 J, followed by 200 J to 300 J in the second, and 360 J in the third.42 Studies have shown that BTE low shocks energy (200 J or less) are equal or superior to 200 J MTE shocks in terminating short duration VT and VF, and produce fewer ST segment changes.43,44, 45
Public Access Defibrillation and Federal Initiatives
The concept of public access defibrillation (PAD) gained momentum when the American Heart Association Task Force on the Future of CPR challenged the medical device industry to create AEDs that would make early defibrillation accessible to the public.46 The rationale for PAD was based on the concern that in many densely populated areas, traditional EMS responders cannot respond in sufficiently short time to perform resuscitation and maximize survival. It was determined that the training and equipping of non-traditional (non-EMS) responders to use AEDs and provide resuscitation until arrival of EMS was a practical and appropriate solution to that problem.
To date, 48 states have passed legislation describing the process of acquisition and use of an AED by lay responders. Since the Food and Drug Administration regulates AEDs as prescription devices, acquisition requires medical involvement. However, details of such requirements for medical involvement vary across states. Elements commonly addressed in state legislation include immunity for rescuers, acquirers, and enablers; training requirements for users; medical supervision or involvement; and EMS notification.
Supporting PAD are three federal initiatives:
- The aforementioned Cardiac Arrest Survival Act (CASA) which instructs the Secretary of Health and Human Services to make recommendations to promote public access to defibrillation programs in federal and other public buildings. The Act also extends Good Samaritan protections to AED users and the acquirers of the devices in any states without such immunities.
- “Guidelines for Public Access Defibrillation in Federal Facilities”47 issued by the Department of Health and Human Services (HHS) and General Services Administration (GSA) to “provide a general framework to initiate a design process for a public access defibrillation (PAD) program in federal facilities.”
- Finally, on April 21, 2001, the Department of Transportation, Federal Aviation Administration issued “Emergency Medical Equipment; Final Rule”48 which requires an AED and other associated first-aid supplies for all passenger-carrying aircraft with at least one flight attendant.
Guidelines for the use of automated external defibrillators (AEDs) in workplace settings
The American College of Occupational and Environmental Medicine (ACOEM) supports the establishment of programs by employers to use automated external defibrillators (AEDs) to manage sudden cardiac arrest in workplace settings. In establishing a workplace AED program, it is important to obtain support for the program from the organization’s leadership, including agreement about the goals, implementation requirements and costs of the program.
ACOEM recommends that employer-sponsored programs for the use of AEDs in workplaces and public settings, include all of the following elements:
- Establishment of a centralized management system for the AED program
It is recommended that a centralized management system be established for the workplace AED program within each organization. It is important that clear lines of responsibility be established for the program, and that roles are defined for those who oversee and monitor the program.
- Medical direction and control of the workplace AED program
It is recommended that all workplace AED programs be under the direction and control of an appropriately qualified physician. It is recommended that all workplace AED programs be medically supervised by an appropriately qualified physician or health care provider licensed for independent practice and be in compliance with medical control requirements of the administrative code of the state where the AED is provided. It is recommended that the responsibilities of the program medical director include helping to develop and/or approving medical aspects of the program. Specific areas where medical direction is important include providing the written authorization required in most locations to acquire an AED, ensuring provisions are made for appropriate initial and continued AED training, and performing a case-by-case review each time an AED is used at the site. It is recommended that additional responsibilities include establishing or integrating the AED program with a quality control system, compliance with regulatory requirements (see recommendation #3) and ensuring proper interface with EMS.
It is recommended that administrative coordination of workplace AED programs be provided by a licensed health care professional or an appropriately qualified health or safety professional responsible for workplace emergency programs. It is recommended that the day-to-day management of the AED program be supervised by the administrative coordinator in consultation with the program medical director for issues of medical control.
- Awareness of and compliance with federal and state regulations
It is important that both the AED program medical director and management responsible for the worksite AED program identify and comply with relevant state legislation49 on public access defibrillation (PAD) and the federal Cardiac Arrest Survival Act.50 These regulations may impose specific requirements that vary from state to state; therefore, a single corporate policy may be insufficient unless it meets the most stringent requirements imposed by all jurisdictions where a workplace AED program is in place.
As federal and state AED legislation requires that every person expected to use an AED be properly trained, it is recommended that training be recognized and standardized. Course content must include CPR, use of the AED, and should be integrated with other first aid responder programs at the workplace. It is recommended that CPR and AED skills review and practice be conducted at least annually, and encouraged semi-annually.51
- Development of written AED program description for each location
It is recommended that a written document describing the workplace AED program be prepared for each location where an AED will be placed. It is recommended that such a written document address all of the 12 recommended program elements stated in this guideline.
- Coordination with local emergency medical services
As is required by many state PAD regulations, it is important that information about each workplace AED program be communicated to community emergency medical services (EMS) providers and coordinated with EMS response protocols.
- Integration with an overall emergency response plan for the worksite
It is recommended that the workplace AED program should be a component of a more general medical emergency response plan, rather than a freestanding program. It is important that the emergency medical response plan describe in sufficient detail the continuum of personnel, equipment, information, and site activities associated with managing the range of anticipated occupational injuries and illnesses for a patient who is breathing or in sudden cardiac arrest. It is recommended that all employees be informed about the medical emergency response plan including the proper means for notifying trained internal and community emergency responders in the event of a suspected cardiac arrest, or other medical emergency. It is recommended that, when a workplace AED program is in place, the part of the workplace medical emergency response plan dealing with suspected cardiac events included specific recommendations about the following:
a. notification of workplace medical personnel and first aid responders during all operating times of the site;
b. assessment of the situation by the first trained responders at the scene;
c. notification of the community emergency medical service (EMS) system;
d. appropriate first aid including body substance isolation procedures and use of CPR and AEDs by first aid responders if indicated;
e. clinically appropriate patient transport from workplace to medical facility, including how appropriate continuation of care will be ensured;
f. responder debriefing and equipment replacement; and
g. methods to review the follow-up care received by the patient.
- Selection and technical consideration of AEDs It is recommended that selection of AED equipment be based on the most current recommendations of the American Heart Association (AHA), available in Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.51 These AHA guidelines state that compared to higher-energy escalating (200 J, 300 J, 360 J) monophasic-waveform defibrillators, relatively low energy level (= 200 J) biphasic waveform defibrillation devices have been shown to be “safe and of equivalent or higher efficacy for termination of VF.”51 It is also recommended that if a higher-energy escalating monophasic defibrillator has been previously acquired, it may be utilized so long as training of responders adequately addresses particular aspects of such devices.
- Ancillary medical equipment and supplies for the workplace AED program
In addition to the AED, other medical equipment and supplies are required to support the safe and complete management of workplace cardiac emergencies. Therefore, it is recommended that the following supplies be provided in addition to the defibrillator as part the AED program:
- bloodborne pathogens responder and clean-up kits52 to ensure compliance with body substance isolation procedures
- CPR barrier masks with oxygen port to permit delivery of supplemental oxygen51
- AED responder kits to support electrode pad connections. Items include a razor (to shave chest hair) and towel (to dry sweat from the chest or after removal of a nitroglycerine transdermal patch);53
- appropriate portable emergency oxygen equipment51,54 to increase oxygen during resuscitation and to support inhalation following restoration of breathing; and
- a CPR audio prompting device51 to guide action and timing sequences of CPR ventilations and compressions.
- Assessment of the proper number and placement of AEDs and supplies
It is recommended that when practical, AEDs be placed in locations throughout a workplace that will allow initiation of resuscitation and use of the AEDs (the “drop-to-shock” interval) within 5 minutes of recognized cardiac arrest. Estimating time needed for transport and set up the AED for various work areas can help determine if a proposed location for AED placement is appropriate.
- Scheduled maintenance and replacement of AED and ancillary equipment
It is important that AEDs be maintained in optimal working condition. It is recommended that, at a minimum, the AED manufacturer’s recommended service schedule be followed, and that records of all servicing and testing be maintained. It is also recommended that any workplace AED program ancillary medical equipment and supplies (e.g., emergency oxygen) used be maintained as recommended by the manufacturers or suppliers. It is recommended that all emergency equipment be evaluated, serviced, or replaced as necessary following use. It is recommended that records be maintained of the dates and details of servicing or replacement of AEDs or ancillary equipment and supplies used.
- Establishment of an AED quality assurance program
It is recommended that an AED quality assurance program be established that includes at least the following components:
a. Medical Review:
A case-by-case review for every use of each AED to treat a human by an appropriately qualified physician. (See also the recommendation above on “Medical Direction and Control.”)
b. Record keeping:
1) records of all AED-related training including names of instructors, workplace personnel trained, courses completed, and dates of initial, review, renewal, or skill practice classes;
2) records of all AED locations, service and updates; and
3) records of medical reviews of AED implementation.
c. Program evaluation:
Standardized methods to assess the efficacy of the program, and a system to remediate or improve components as necessary.
- Periodic review and modification of the Workplace AED program protocols
It is recommended that all components of the workplace AED program be reviewed at least annually and modified as appropriate. As personnel or work practices evolve, there may be need to change the location, means of access, or procedures used to implement AEDs in the workplace.
ACOEM supports ongoing efforts to enhance emergency response to medical emergencies in the occupational environment. Development of programs to utilize AEDs is a reasonable and appropriate aspect of such programs to manage sudden cardiac arrest, an important cause of morbidity and mortality among working age adults. Implementation of such an AED program, which should be a component of a more general worksite emergency response plan, requires clearly defined medical direction and medical control.
This ACOEM guideline was prepared by Larry M. Starr, PhD, under the auspices of the Council on Scientific Affairs. It was peer-reviewed by the members of the Council and approved by the ACOEM Board of Directors on February 11, 2001.
The guideline was reaffirmed in its entirety by the ACOEM Board of Directors on May 6, 2006.