Automated external defibrillator
Encyclopedia
An automated external defibrillator or AED is a portable
electronic device that automatically diagnoses the potentially life threatening cardiac arrhythmias of ventricular fibrillation
and ventricular tachycardia
in a patient
, and is able to treat them through defibrillation
, the application of electrical therapy which stops the arrhythmia, allowing the heart to reestablish an effective rhythm.
AEDs are designed to be simple to use for the layman
, and the use of AEDs is taught in many first aid
, first responder, and basic life support
(BLS) level CPR
classes.
. The rhythms that the device will treat are usually limited to:
In each of these two types of shockable cardiac arrhythmia, the heart is active, but in a life-threatening, dysfunctional pattern. In ventricular tachycardia
, the heart beats too fast to effectively pump blood. Ultimately, ventricular tachycardia leads to ventricular fibrillation
. In ventricular fibrillation
, the electrical activity of the heart becomes chaotic, preventing the ventricle
from effectively pumping blood. The fibrillation in the heart decreases over time, and will eventually reach asystole
.
AEDs, like all defibrillators, are not designed to shock asystole
('flat line' patterns) as this will not have a positive clinical outcome. The asystolic patient only has a chance of survival if, through a combination of CPR and cardiac stimulant
drugs, one of the shockable rhythms can be established, which makes it imperative for CPR to be carried out prior to the arrival of a defibrillator.
and death
. After approximately three to five minutes, irreversible brain/tissue damage may begin to occur. For every minute that a person in cardiac arrest goes without being successfully treated (by defibrillation), the chance of survival decreases by 7 percent per minute in the first minutes, and decreases by 10 percent per minute as time advances beyond ~3 minutes.
if the heart rate is too slow (bradycardia
) and perform other functions which require a skilled operator able to read electrocardiograms.
Bras with a metal underwire
and piercings on the torso must be removed before using the AED on someone to avoid interference.American TV show Mythbusters found evidence that use of a defibrillator on a woman wearing an underwire bra can lead to arcing or fire but only in unusual and unlikely circumstances.
A study analyzed the effects of having AEDs immediately present during Chicago's Heart Start program over a two year period. Of 22 individuals 18 were in a cardiac arrhythmia which AEDs can treat (Vfib or Vtach). Of these 18, 11 survived. Of these 11 patients, 6 were treated by good Samaritan bystanders with absolutely no previous training in AED use.
Automated external defibrillators are generally either held by trained personnel who will attend events or are public access units which can be found in places including corporate and government
office
s, shopping centres, airport
s, airplanes, restaurant
s, casino
s, hotel
s, sports stadium
s, school
s and universities
, community centers, fitness centers, health clubs, theme parks
, workplaces and any other location where people may congregate.
Maimonides Medical Center
in Borough Park, Brooklyn
was the first hospital in the United States to implement fully automated external defibrillators at the bedside.
The location of a public access AED should take in to account where large groups of people gather, regardless of age or activity. Children as well as adults may fall victim to sudden cardiac arrest (SCA)
In many areas, emergency vehicles are likely to carry AEDs, with some ambulance
s carrying an AED in addition to manual defibrillators. Police or fire vehicles often carry an AED for first responder use. Some areas have dedicated community first responders, who are volunteers tasked with keeping an AED and taking it to any victims in their area. AEDs are also increasingly common on commercial airliners, cruise ships, and other transportation facilities.
High-rise buildings are densely populated, but are more difficult to access by emergency crews facing heavy traffic and security barriers. It has been suggested that AEDs carried on elevators could save critical minutes for cardiac arrest victims, and reduce their deployment cost.
In order to make them highly visible, public access AEDs are often brightly colored, and are mounted in protective cases near the entrance of a building. When these protective cases are opened or the defibrillator is removed, some will sound a buzzer to alert nearby staff to their removal, though this does not necessarily summon emergency services; trained AED operators should know to phone for an ambulance when sending for or using an AED. In September 2008, the International Liaison Committee on Resuscitation
issued a 'universal AED sign' to be adopted throughout the world to indicate the presence of an AED, and this is shown on the right.
A trend that is developing is the purchase of AEDs to be used in the home, particularly by those with known existing heart conditions. The number of devices in the community has grown as prices have fallen to affordable levels. There has been some concern among medical professionals that these home users do not necessarily have appropriate training, and many advocate the more widespread use of community responders, who can be appropriately trained and managed.
Typically, an AED kit will contain a face shield for providing a barrier between patient and first aider during rescue breathing; a pair of nitrile rubber
gloves; a pair of trauma shears
for cutting through a patient's clothing to expose the chest; a small towel for wiping away any moisture on the chest, and a razor for shaving those with very hairy chests.
All manufacturers mark their electrode pads with an expiration date, and it is important to ensure that the pads are in date. This is usually marked on the outside of the pads. Some models are designed to make this date visible through a 'window', although others will require the opening of the case to find the date stamp.
It is also important to ensure that the AED unit's batteries have not expired. The AED manufacturer will specify how often the batteries should be replaced.
of the victim, as opposed to internal defibrillators
, which have electrode
s surgically implanted inside the body of a patient.
Automatic refers to the unit's ability to autonomously analyse the patient's condition, and to assist this, the vast majority of units have spoken prompts, and some may also have visual displays to instruct the user.
When turned on or opened, the AED will instruct the user to connect the electrodes (pads) to the patient. Once the pads are attached, everyone should avoid touching the patient so as to avoid false readings by the unit. The pads allow the AED to examine the electrical output from the heart and determine if the patient is in a shockable rhythm (either ventricular fibrillation
or ventricular tachycardia
). If the device determines that a shock is warranted, it will use the battery to charge its internal capacitor in preparation to deliver the shock. This system is not only safer (charging only when required), but also allows for a faster delivery of the electrical current.
When charged, the device instructs the user to ensure no one is touching the patient and then to press a button to deliver the shock; human intervention is usually required to deliver the shock to the patient in order to avoid the possibility of accidental injury to another person (which can result from a responder or bystander touching the patient at the time of the shock). Depending on the manufacturer and particular model, after the shock is delivered most devices will analyze the patient and either instruct CPR to be given, or administer another shock.
Many AED units have an 'event memory' which store the ECG of the patient along with details of the time the unit was activated and the number and strength of any shocks delivered. Some units also have voice recording abilities to monitor the actions taken by the personnel in order to ascertain if these had any impact on the survival outcome. All this recorded data can be either downloaded to a computer or printed out so that the providing organisation or responsible body is able to see the effectiveness of both CPR and defibrillation. Some AED units even provide feedback on the quality of the compressions provided by the rescuer
The first commercially available AEDs were all of a monophasic type, which gave a high-energy shock, up to 360 to 400 joules depending on the model. This caused increased cardiac injury and in some cases second and third-degree burns around the shock pad sites. Newer AEDs (manufactured after late 2003) have tended to utilise biphasic algorithms which give two sequential lower-energy shocks of 120 - 200 joules, with each shock moving in an opposite polarity between the pads. This lower-energy waveform has proven more effective in clinical tests, as well as offering a reduced rate of complications and reduced recovery time.
Unlike regular defibrillators, an automated external defibrillator requires minimal training to use. It automatically diagnoses the heart rhythm and determines if a shock is needed. Automatic models will administer the shock without the user's command. Semi-automatic models will tell the user that a shock is needed, but the user must tell the machine to do so, usually by pressing a button. In most circumstances, the user cannot override a "no shock" advisory by an AED. Some AEDs may be used on children - those under 55 lbs (25 kg) in weight or under age 8. If a particular model of AED is approved for pediatric use, all that is required is the use of more appropriate pads.
All AEDs approved for use in the United States
use an electronic voice to prompt users through each step. Because the user of an AED may be hearing impaired
, many AEDs now include visual prompts as well. Most units are designed for use by non-medical operators. Their ease of use has given rise to the notion of public access defibrillation (PAD), which experts agree has the potential to be the single greatest advance in the treatment of out-of-hospital cardiac arrest
since the invention of CPR.
in the United States
include the "good faith" use of an AED by any person under Good Samaritan law
s. "Good faith" protection under a Good Samaritan law means that a volunteer responder (not acting as a part of one's occupation) cannot be held civilly liable for the harm or death of a victim by providing improper or inadequate care, given that the harm or death was not intentional and the responder was acting within the limits of their training and in good faith. In the United States, Good Samaritan laws provide some protection for the use of AEDs by trained and untrained responders. AEDs create little liability if used correctly; NREMT-B and many state EMT
training and many CPR classes incorporate or offer AED education as a part of their program. In addition to Good Samaritan laws, Ontario, Canada also has the "Chase McEachern
Act (Heart Defibrillator Civil Liability), 2007 (Bill 171 – Subsection N)", passed in June, 2007, which protects individuals from liability for damages that may occur from their use of an AED to save someone's life at the immediate scene of an emergency unless damages are caused by gross negligence.
Portable
Portable may refer to:* Portable building, a manufactured structure that is built off site and moved in upon completion of site and utility work...
electronic device that automatically diagnoses the potentially life threatening cardiac arrhythmias of ventricular fibrillation
Ventricular fibrillation
Ventricular fibrillation is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricles in the heart, making them quiver rather than contract properly. Ventricular fibrillation is a medical emergency and most commonly identified arrythmia in cardiac arrest...
and ventricular tachycardia
Ventricular tachycardia
Ventricular tachycardia is a tachycardia, or fast heart rhythm, that originates in one of the ventricles of the heart...
in a patient
Patient
A patient is any recipient of healthcare services. The patient is most often ill or injured and in need of treatment by a physician, advanced practice registered nurse, veterinarian, or other health care provider....
, and is able to treat them through defibrillation
Defibrillation
Defibrillation is a common treatment for life-threatening cardiac arrhythmias, ventricular fibrillation and pulseless ventricular tachycardia. Defibrillation consists of delivering a therapeutic dose of electrical energy to the affected heart with a device called a defibrillator...
, the application of electrical therapy which stops the arrhythmia, allowing the heart to reestablish an effective rhythm.
AEDs are designed to be simple to use for the layman
Layman
A layperson or layman is a person who is not an expert in a given field of knowledge. The term originally meant a member of the laity, i.e. a non-clergymen, but over the centuries shifted in definition....
, and the use of AEDs is taught in many first aid
First aid
First aid is the provision of initial care for an illness or injury. It is usually performed by non-expert, but trained personnel to a sick or injured person until definitive medical treatment can be accessed. Certain self-limiting illnesses or minor injuries may not require further medical care...
, first responder, and basic life support
Basic life support
Basic life support is the level of medical care which is used for patients with life-threatening illnesses or injuries until the patient can be given full medical care at a hospital. It can be provided by trained medical personnel, including emergency medical technicians, paramedics, and by...
(BLS) level CPR
Cardiopulmonary resuscitation
Cardiopulmonary resuscitation is an emergency procedure which is performed in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person in cardiac arrest. It is indicated in those who are unresponsive...
classes.
Conditions that the Device Treats
An automated external defibrillator is used in cases of life threatening cardiac arrhythmias which lead to cardiac arrestCardiac arrest
Cardiac arrest, is the cessation of normal circulation of the blood due to failure of the heart to contract effectively...
. The rhythms that the device will treat are usually limited to:
- Pulseless Ventricular tachycardiaVentricular tachycardiaVentricular tachycardia is a tachycardia, or fast heart rhythm, that originates in one of the ventricles of the heart...
(shortened to VT or V-Tach) - Ventricular fibrillationVentricular fibrillationVentricular fibrillation is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricles in the heart, making them quiver rather than contract properly. Ventricular fibrillation is a medical emergency and most commonly identified arrythmia in cardiac arrest...
(shortened to VF or V-Fib)
In each of these two types of shockable cardiac arrhythmia, the heart is active, but in a life-threatening, dysfunctional pattern. In ventricular tachycardia
Ventricular tachycardia
Ventricular tachycardia is a tachycardia, or fast heart rhythm, that originates in one of the ventricles of the heart...
, the heart beats too fast to effectively pump blood. Ultimately, ventricular tachycardia leads to ventricular fibrillation
Ventricular fibrillation
Ventricular fibrillation is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricles in the heart, making them quiver rather than contract properly. Ventricular fibrillation is a medical emergency and most commonly identified arrythmia in cardiac arrest...
. In ventricular fibrillation
Ventricular fibrillation
Ventricular fibrillation is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricles in the heart, making them quiver rather than contract properly. Ventricular fibrillation is a medical emergency and most commonly identified arrythmia in cardiac arrest...
, the electrical activity of the heart becomes chaotic, preventing the ventricle
Ventricle (heart)
In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
from effectively pumping blood. The fibrillation in the heart decreases over time, and will eventually reach asystole
Asystole
In medicine, asystole is a state of no cardiac electrical activity, hence no contractions of the myocardium and no cardiac output or blood flow...
.
AEDs, like all defibrillators, are not designed to shock asystole
Asystole
In medicine, asystole is a state of no cardiac electrical activity, hence no contractions of the myocardium and no cardiac output or blood flow...
('flat line' patterns) as this will not have a positive clinical outcome. The asystolic patient only has a chance of survival if, through a combination of CPR and cardiac stimulant
Cardiac stimulant
A cardiac stimulant is a substance which acts as a stimulant of the heart -- for example, via positive chronotropic or inotropic action.Examples of cardiac stimulant drugs are cocaine and methamphetamine....
drugs, one of the shockable rhythms can be established, which makes it imperative for CPR to be carried out prior to the arrival of a defibrillator.
Effect of Delayed Treatment
Uncorrected, these cardiac conditions (ventricular tachycardia, ventricular fibrillation, asystole) rapidly lead to irreversible brain damageBrain damage
"Brain damage" or "brain injury" is the destruction or degeneration of brain cells. Brain injuries occur due to a wide range of internal and external factors...
and death
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....
. After approximately three to five minutes, irreversible brain/tissue damage may begin to occur. For every minute that a person in cardiac arrest goes without being successfully treated (by defibrillation), the chance of survival decreases by 7 percent per minute in the first minutes, and decreases by 10 percent per minute as time advances beyond ~3 minutes.
Requirements for use
AEDs are designed to be used by laypersons who ideally should have received AED training. This is in contrast to more sophisticated manual and semi-automatic defibrillators used by health professionals, which can act as a pacemakerArtificial pacemaker
A pacemaker is a medical device that uses electrical impulses, delivered by electrodes contacting the heart muscles, to regulate the beating of the heart...
if the heart rate is too slow (bradycardia
Bradycardia
Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...
) and perform other functions which require a skilled operator able to read electrocardiograms.
Bras with a metal underwire
Underwire bra
An underwire bra is a brassiere with a wire built into the underside of the cup intended to lift, separate, shape, and provide additional support for a woman's breasts...
and piercings on the torso must be removed before using the AED on someone to avoid interference.American TV show Mythbusters found evidence that use of a defibrillator on a woman wearing an underwire bra can lead to arcing or fire but only in unusual and unlikely circumstances.
A study analyzed the effects of having AEDs immediately present during Chicago's Heart Start program over a two year period. Of 22 individuals 18 were in a cardiac arrhythmia which AEDs can treat (Vfib or Vtach). Of these 18, 11 survived. Of these 11 patients, 6 were treated by good Samaritan bystanders with absolutely no previous training in AED use.
Placement and Availability
Government
Government refers to the legislators, administrators, and arbitrators in the administrative bureaucracy who control a state at a given time, and to the system of government by which they are organized...
office
Office
An office is generally a room or other area in which people work, but may also denote a position within an organization with specific duties attached to it ; the latter is in fact an earlier usage, office as place originally referring to the location of one's duty. When used as an adjective, the...
s, shopping centres, airport
Airport
An airport is a location where aircraft such as fixed-wing aircraft, helicopters, and blimps take off and land. Aircraft may be stored or maintained at an airport...
s, airplanes, restaurant
Restaurant
A restaurant is an establishment which prepares and serves food and drink to customers in return for money. Meals are generally served and eaten on premises, but many restaurants also offer take-out and food delivery services...
s, casino
Casino
In modern English, a casino is a facility which houses and accommodates certain types of gambling activities. Casinos are most commonly built near or combined with hotels, restaurants, retail shopping, cruise ships or other tourist attractions...
s, hotel
Hotel
A hotel is an establishment that provides paid lodging on a short-term basis. The provision of basic accommodation, in times past, consisting only of a room with a bed, a cupboard, a small table and a washstand has largely been replaced by rooms with modern facilities, including en-suite bathrooms...
s, sports stadium
Sports Stadium
Sports Stadium was an Irish television sport programme on Raidió Teilifís Éireann . Broadcast between 1973 and 1997, it was RTÉ's flagship sports programme and one of its longest-running shows....
s, school
School
A school is an institution designed for the teaching of students under the direction of teachers. Most countries have systems of formal education, which is commonly compulsory. In these systems, students progress through a series of schools...
s and universities
Higher education
Higher, post-secondary, tertiary, or third level education refers to the stage of learning that occurs at universities, academies, colleges, seminaries, and institutes of technology...
, community centers, fitness centers, health clubs, theme parks
Amusement park
thumb|Cinderella Castle in [[Magic Kingdom]], [[Disney World]]Amusement and theme parks are terms for a group of entertainment attractions and rides and other events in a location for the enjoyment of large numbers of people...
, workplaces and any other location where people may congregate.
Maimonides Medical Center
Maimonides Medical Center
Maimonides Medical Center is a non-profit, non-sectarian hospital located in Borough Park, Brooklyn. Maimonides is both a treatment facility and academic medical center with 705 beds, and more than 70 primary care and sub-specialty programs...
in Borough Park, Brooklyn
Brooklyn
Brooklyn is the most populous of New York City's five boroughs, with nearly 2.6 million residents, and the second-largest in area. Since 1896, Brooklyn has had the same boundaries as Kings County, which is now the most populous county in New York State and the second-most densely populated...
was the first hospital in the United States to implement fully automated external defibrillators at the bedside.
The location of a public access AED should take in to account where large groups of people gather, regardless of age or activity. Children as well as adults may fall victim to sudden cardiac arrest (SCA)
In many areas, emergency vehicles are likely to carry AEDs, with some ambulance
Ambulance
An ambulance is a vehicle for transportation of sick or injured people to, from or between places of treatment for an illness or injury, and in some instances will also provide out of hospital medical care to the patient...
s carrying an AED in addition to manual defibrillators. Police or fire vehicles often carry an AED for first responder use. Some areas have dedicated community first responders, who are volunteers tasked with keeping an AED and taking it to any victims in their area. AEDs are also increasingly common on commercial airliners, cruise ships, and other transportation facilities.
High-rise buildings are densely populated, but are more difficult to access by emergency crews facing heavy traffic and security barriers. It has been suggested that AEDs carried on elevators could save critical minutes for cardiac arrest victims, and reduce their deployment cost.
In order to make them highly visible, public access AEDs are often brightly colored, and are mounted in protective cases near the entrance of a building. When these protective cases are opened or the defibrillator is removed, some will sound a buzzer to alert nearby staff to their removal, though this does not necessarily summon emergency services; trained AED operators should know to phone for an ambulance when sending for or using an AED. In September 2008, the International Liaison Committee on Resuscitation
International Liaison Committee on Resuscitation
The International Liaison Committee on Resuscitation was formed in 1992 to provide an opportunity for the major organizations in resuscitation to work together on CPR and ECC protocols...
issued a 'universal AED sign' to be adopted throughout the world to indicate the presence of an AED, and this is shown on the right.
A trend that is developing is the purchase of AEDs to be used in the home, particularly by those with known existing heart conditions. The number of devices in the community has grown as prices have fallen to affordable levels. There has been some concern among medical professionals that these home users do not necessarily have appropriate training, and many advocate the more widespread use of community responders, who can be appropriately trained and managed.
Typically, an AED kit will contain a face shield for providing a barrier between patient and first aider during rescue breathing; a pair of nitrile rubber
Nitrile rubber
Nitrile rubber, also known as Buna-N, Perbunan, or NBR, is a synthetic rubber copolymer of acrylonitrile and butadiene. Trade names include Nipol, Krynac and Europrene....
gloves; a pair of trauma shears
Trauma shears
Trauma shears, also known as tuff cuts, are a type of scissors used by paramedics and other emergency medical personnel to quickly and safely cut clothing from injured people...
for cutting through a patient's clothing to expose the chest; a small towel for wiping away any moisture on the chest, and a razor for shaving those with very hairy chests.
Preparation for operation
Most manufacturers recommend checking the AED before every period of duty or on a regular basis for fixed units. Some units need to be switched on in order to perform a self check; other models have a self check system built in with a visible indicator.All manufacturers mark their electrode pads with an expiration date, and it is important to ensure that the pads are in date. This is usually marked on the outside of the pads. Some models are designed to make this date visible through a 'window', although others will require the opening of the case to find the date stamp.
It is also important to ensure that the AED unit's batteries have not expired. The AED manufacturer will specify how often the batteries should be replaced.
Mechanism of operation
An AED is external because the operator applies the electrode pads to the bare chestChest
The chest is a part of the anatomy of humans and various other animals. It is sometimes referred to as the thorax or the bosom.-Chest anatomy - Humans and other hominids:...
of the victim, as opposed to internal defibrillators
Implantable cardioverter-defibrillator
An implantable cardioverter-defibrillator is a small battery-powered electrical impulse generator which is implanted in patients who are at risk of sudden cardiac death due to ventricular fibrillation and ventricular tachycardia. The device is programmed to detect cardiac arrhythmia and correct it...
, which have electrode
Electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit...
s surgically implanted inside the body of a patient.
Automatic refers to the unit's ability to autonomously analyse the patient's condition, and to assist this, the vast majority of units have spoken prompts, and some may also have visual displays to instruct the user.
When turned on or opened, the AED will instruct the user to connect the electrodes (pads) to the patient. Once the pads are attached, everyone should avoid touching the patient so as to avoid false readings by the unit. The pads allow the AED to examine the electrical output from the heart and determine if the patient is in a shockable rhythm (either ventricular fibrillation
Ventricular fibrillation
Ventricular fibrillation is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricles in the heart, making them quiver rather than contract properly. Ventricular fibrillation is a medical emergency and most commonly identified arrythmia in cardiac arrest...
or ventricular tachycardia
Ventricular tachycardia
Ventricular tachycardia is a tachycardia, or fast heart rhythm, that originates in one of the ventricles of the heart...
). If the device determines that a shock is warranted, it will use the battery to charge its internal capacitor in preparation to deliver the shock. This system is not only safer (charging only when required), but also allows for a faster delivery of the electrical current.
When charged, the device instructs the user to ensure no one is touching the patient and then to press a button to deliver the shock; human intervention is usually required to deliver the shock to the patient in order to avoid the possibility of accidental injury to another person (which can result from a responder or bystander touching the patient at the time of the shock). Depending on the manufacturer and particular model, after the shock is delivered most devices will analyze the patient and either instruct CPR to be given, or administer another shock.
Many AED units have an 'event memory' which store the ECG of the patient along with details of the time the unit was activated and the number and strength of any shocks delivered. Some units also have voice recording abilities to monitor the actions taken by the personnel in order to ascertain if these had any impact on the survival outcome. All this recorded data can be either downloaded to a computer or printed out so that the providing organisation or responsible body is able to see the effectiveness of both CPR and defibrillation. Some AED units even provide feedback on the quality of the compressions provided by the rescuer
The first commercially available AEDs were all of a monophasic type, which gave a high-energy shock, up to 360 to 400 joules depending on the model. This caused increased cardiac injury and in some cases second and third-degree burns around the shock pad sites. Newer AEDs (manufactured after late 2003) have tended to utilise biphasic algorithms which give two sequential lower-energy shocks of 120 - 200 joules, with each shock moving in an opposite polarity between the pads. This lower-energy waveform has proven more effective in clinical tests, as well as offering a reduced rate of complications and reduced recovery time.
Simplicity of use
All AEDs approved for use in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
use an electronic voice to prompt users through each step. Because the user of an AED may be hearing impaired
Hearing impairment
-Definition:Deafness is the inability for the ear to interpret certain or all frequencies of sound.-Environmental Situations:Deafness can be caused by environmental situations such as noise, trauma, or other ear defections...
, many AEDs now include visual prompts as well. Most units are designed for use by non-medical operators. Their ease of use has given rise to the notion of public access defibrillation (PAD), which experts agree has the potential to be the single greatest advance in the treatment of out-of-hospital cardiac arrest
Cardiac arrest
Cardiac arrest, is the cessation of normal circulation of the blood due to failure of the heart to contract effectively...
since the invention of CPR.
Liability
Automated external defibrillators are now easy enough to use that most statesU.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
include the "good faith" use of an AED by any person under Good Samaritan law
Good Samaritan law
Good Samaritan laws are laws or acts protecting those who choose to serve and tend to others who are injured or ill. They are intended to reduce bystanders' hesitation to assist, for fear of being sued or prosecuted for unintentional injury or wrongful death...
s. "Good faith" protection under a Good Samaritan law means that a volunteer responder (not acting as a part of one's occupation) cannot be held civilly liable for the harm or death of a victim by providing improper or inadequate care, given that the harm or death was not intentional and the responder was acting within the limits of their training and in good faith. In the United States, Good Samaritan laws provide some protection for the use of AEDs by trained and untrained responders. AEDs create little liability if used correctly; NREMT-B and many state EMT
Emergency medical technician
Emergency Medical Technician or Ambulance Technician are terms used in some countries to denote a healthcare provider of emergency medical services...
training and many CPR classes incorporate or offer AED education as a part of their program. In addition to Good Samaritan laws, Ontario, Canada also has the "Chase McEachern
Chase McEachern
Chase McEachern was a boy from Barrie, Ontario, Canada, who campaigned to have it mandatory that heart defibrillators be made available at schools and hockey arenas. - Death :Unfortunately, on Feb...
Act (Heart Defibrillator Civil Liability), 2007 (Bill 171 – Subsection N)", passed in June, 2007, which protects individuals from liability for damages that may occur from their use of an AED to save someone's life at the immediate scene of an emergency unless damages are caused by gross negligence.