Factors to Consider when using an AED

Factors to Consider when using an AED


When treating a victim that has gone into cardiac arrest there are a few considerations to be made when it comes to using an AED (automated external defibrillator).

These considerations need to be made on

  • Paediatric patients
  • Wet or sweaty patients
  • Patients with a hairy chest
  • Patients with a medication patch
  • Patients with a pacemaker or implantable defibrillator


If In doubt, start performing chest compressions and have someone contact emergency medical services via phone before you deliver an electric shock.  If there are obvious signs of a cardiac arrest, acting fast will increase the patient’s chance of survival—no matter what other factors are present.


Treating a Paediatric Patient


Cardiac arrest in children is rare but still a possibility. Child patients require a reduced electrical shock if they are under eight years old or weigh less than 55 pounds. To cater to paediatric patients, some external defibrillators have a special paediatric setting, and others come with child electrode pads (either included with the device or sold separately).

For a child under age eight, adjusting an AED can be seen in example such as the below;

  • HeartSine Samaritan PAD 350P. Unplug the adult electrode Pad-Pak and plug in the child electrode pads (sold separately). Follow the audio prompts and press the shock button when directed.


If no child pads are available, and your device doesn’t have a child setting, you can use standard adult pads. However, the chest placement is different for paediatric patients. One pad should be placed in the centre of the chest, and the other in the centre of the back. Use this placement for paediatric patients, whether you use adult or child pads.

See image below for reference;

For an infant under 12 months, a manual defibrillator is more appropriate than an AED (automated defibrillator) —especially if no paediatric pads are available. However, it’s much better to use a portable defibrillator (with paediatric or adult pads) than to do nothing at all.

Treating a Sweaty or Water-Submerged Patient


Special considerations when using an AED with a patient also apply when the patient is wet or damp from sweat. Because water is an excellent conductor of electricity, the power of the shock would be dispersed across the patient’s body and be less effective where it’s needed the most.

When treating a victim of cardiac arrest who is wet or damp, remove them from the water (if they are immersed) and take them to a dry place. Dry off their chest area as much as possible and apply the electrode pads. There is no need to completely dry the patient from head to toe as time is of the essence, focus only on completely drying the chest area, specifically the area between the pads.

The most important factor is that the victim’s chest be dry so that the shock is delivered straight to the heart. If the victim is in a puddle or lying on a wet area of the floor but their chest is dry, simply move them away from the water and use the defibrillator as normal.


Treating a Patient with a Hairy Chest


When a cardiac arrest victim has excessive chest hair, it may be difficult for the electrode pad to analyse their heart rhythm and deliver an appropriately timed shock. This is because the hair would lift the pad up and off the patient’s chest, preventing full contact with the skin. The hair would also make it more difficult for the gel on the electrode pad to adhere to the skin.

There are three main solutions to the issue of chest hair, as recommended by the American Heart Association’s Basic Life Support Manual:  BLS Provider Manual eBook (heart.org)

  1. Shave the hair off the area where the patch will be applied. It is sensible to keep a disposable razor stored with every AED specifically for this purpose. Most first-aid kids and first-responder kits should include at least one razor.
  2. If you don’t have a razor and the device continues to prompt you with “check pads,” push down hard on the electrode pads to increase conductivity. Then remove your hands when instructed to “stand clear.”
  3. If the machine still doesn’t respond, you can strip the pad quickly off the patient’s chest to remove some of the hair. Then apply a new set of pads. Only do this if you have extra pads on hand.


Treating a Patient with a Transdermal Medication Patch


Transdermal medication patches have been used since the 1970’s to deliver active medication, such as a hormone or nicotine, at a gradual rate through the skin. In the case of a cardiac arrest, medication patches present a burn hazard when using an external automated defibrillator if the shock is delivered over the patch.

Before applying an AED, remove the medication patch and wipe any sticky residue off the patient’s skin. It’s a good idea to wear gloves when removing the patch so that the medication is not absorbed through your skin.


Treating a Patient with a Pacemaker or Implantable Defibrillator


Pacemakers and implantable defibrillators make up the last category of special considerations when using an AED. If you place an AED directly over a pacemaker or defibrillator, the device may block the delivery of the shock. Instead, place the electrode pad a few inches lower or try an anterior-posterior (front-and-back) pad placement instead.

You can usually tell if a cardiac arrest victim has an implanted pacemaker or defibrillator because they will have a scar on either side of their upper chest or abdomen with a hard lump the size of a deck of playing cards or smaller. Most often this will be near the heart, on the left side of the chest, in which case it will not interfere with the standard pad placements. If they have suffered a sudden cardiac arrest, it’s almost certain that the device has stopped working. Don’t worry about damaging the device as this can be replaced.


With a few simple adjustments, you can use an automated external defibrillator on the patients mentioned above, as you would on any other. Make sure your AED is equipped with paediatric pads, a razor, and a pair of gloves and you should be ready for anything.


Special Considerations When Using an AED Device (aedleader.com)

Feasibility of a Novel ECG Electrode Placement Method in New-born Infants

International newborn resuscitation guidelines recommend electrocardiogram (ECG) heart rate (HR) monitoring at birth. The below study evaluated the application time of pre-set ECG electrodes fixed to a polyethene patch allowing adhesive-free attachment to the wet skin of the newborn chest. Using a three-electrode pre-set ECG patch configuration, application success was calculated using video analysis and measured at three time points, the time to

  1. Apply the electrodes
  2. Detect recognizable QRS complexes after application
  3. Display a heart rate after electrode application.

A prospective observational study in two UK tertiary maternity units was undertaken with 71 newborns including 23 who required resuscitation.

The study concluded that pre-set ECG chest electrodes allow rapid heart rate information at birth without electrode detachment or compromising skin integrity.


Read full article below;

Feasibility of a Novel ECG Electrode Placement Method in Newborn Infants – PMC (nih.gov)

The AED Project: Multiorganization Collaboration to Streamline Automatic External Defibrillator Data in Out-of-Hospital Cardiac Arrests

In patients with out-of-hospital cardiac arrest (OHCA), automated external defibrillator (AED) devices contain valuable data about a patient’s initial rhythm. The retrieval process was previously without protocol, despite its critical role in the patient journey.

A Plan-Do-Study-Act model was carried out at the cardiology department at Royal Jubilee Hospital, British Columbia, Canada. They collaborated with the emergency health services of British Columbia to cocreate a request process for data from AED’s used by first responders. The British Columbia Fire Departments, which the study stated to be under municipal oversight, required an alternate strategy. Educational presentations allowed for feedback and advancement. Patients surviving OHCA and were transferred to the regional cardiac centre, were consecutively enrolled from November 2018 to April 2020. The study evaluated the timeliness of AED information retrieval and tracked the process to admission. A retrospective chart review also informed specifics after admission and a survey to the Coronary Intensive Care Unit staff was used to assess clinical utility.

The AED project showed that effective multiorganization collaboration can improve the capacity for health care teams to make informed decisions on patient care. Through timely access to AED data, details from the time of OHCA can have direct integration into clinical decision-making. Overall, this could spare patients from the risk of complications of unnecessary procedures, decrease workload burden of health care staff, and for proper utilization of hospital resources.


For full study click below;

The AED Project: Multiorganization Collaboration to Streamline Automatic External Defibrillator Data in Out-of-Hospital Cardiac Arrests – PMC (nih.gov)

Underutilisation of public access defibrillation is related to retrieval distance and time dependent availability

Public access defibrillation doubles the chances of neurologically intact survival following out-of-hospital cardiac arrest (OHCA). Although there are increasing numbers of automated external defibrillators (AEDs) available in the community, it is said they are used infrequently, despite often being available. This study aimed to match OHCAs with known AED locations to understand AED availability, the effects of reduced AED availability at night and the operational radius at which they can be effectively retrieved.

Results determined that existing AEDs are in fact being underused, with 36.4% of out of hospital cardiac arrests occurring withing 500m of an AED. Although more AEDs will improve availability, greater use can be made of existing AEDs, particularly by ensuring they are all available on a 24/7 basis.

Read full study below;

Underutilisation of public access defibrillation is related to retrieval distance and time-dependent availability | Heart (bmj.com)

Source – Underutilisation of public access defibrillation is related to retrieval distance and time-dependent availability – PubMed (nih.gov)

Evolution of the ECG Machine

Evolution of the ECG Machine



An electrocardiogram or “ECG machine” is a device that helps physicians understand and interpret the electrical signals that are produced by the heart as it contracts. By doing so, they can diagnose potential heart issues.


Over the past few decades, there have been great advances in the field of medicine. One such area is cardiac care, where modern technologies have led to a better understanding and treatment of heart conditions. When it comes to heart health, the evolution of ECG machines has played a critical role for both doctors and patients alike.


The below article explores the ECG machine, its evolution, and what impact it had on cardiac care.


“ECG machines are now a staple in every hospital and medical clinic and is one of the most common tests requested by cardiologists for their patients.


1887-1930: The Early Days of ECGs 


The first ECGs were rudimentary at best, but they laid the groundwork for the more advanced machines we have today. It was not until 1903 that Willem Einthoven, a Dutch physiologist invented the string galvanometer, which improved the accuracy of ECGs by measuring small electrical currents. This innovation earned Einthoven the Nobel Prize in Physiology or Medicine in 1924.

By the 1930’s, ECGs were being used routinely in hospitals to diagnose heart conditions like arrhythmias and myocardial infarctions (heart attacks). However, these early machines were large and bulky, making them difficult to transport from one location to another. Additionally, they required trained technicians to operate them, which limited their use outside of hospitals.


1930’s-1960’s: The Advent of Portable ECGs 


In 1939, engineer Norman Jolliffe unveiled the first portable ECG machine, which weighed just 35 pounds (16 kg). This machine allowed doctors to more easily transport ECGs from one location to another and even administer them outside traditional hospital settings.

Other advances during this time included the development of self-adhesive electrodes and disposable paper ones, which made recording an ECG quicker and easier than ever before. By the 1960’s, beat-to-beat reporting became possible thanks to new technological advances, furthering the use of ECGs in identifying heart conditions. To make ECG machines more accessible and affordable, several modifications were made over the years. One of the most important modifications was the development of solid-state electronics in the 1950’s.

This replaced the need for string galvanometers with much smaller transistors—which made ECG machines smaller, lighter, and less expensive. The 1950’s saw the development of portable ECGs which allowed patients to be mobile while still monitoring their heart activity. In 1957, John Winters started marketing his own design of an ambulatory ECG called the “Dynamo Cardio scope.”

This machine increased the mobility of patients as well as allowed longer periods of monitoring. However, these ambulatory ECGs were large, bulky, and not very user-friendly, which made them impractical for widespread use. In 1975 World Heal Corporation released their own version called the “Mini Mitter” or “Holter Monitor,” which was much smaller and lighter weight. The Holter monitor became the industry standard for ambulatory ECGs and is still used today in many hospitals around the world.


1970’s-Present: Modern Developments in ECG Technology


The 1970’s saw several important developments in ECG technology, including the introduction of digital readouts and computerized analysis. These advances made it possible for non-specialists to operate ECG machines and led to increased accuracy in diagnosis.

ECG machines continued to evolve throughout the second half of the 20th century. In recent years, digital technology has been used to create compact, handheld devices that can be easily transported from one location to another. Some modern ECG machines can be wirelessly connected to smartphones and other devices so that patients can receive real-time monitoring. Eventually, technology continued to miniaturize further until we arrived at wearable devices such as smartwatches that are now capable of performing Single Lead ECG.

Some of the latest innovations in ECG technology include ultra-portable ECG devices that measure the equivalent of a 12 Lead ECG, without leads, just by touch with the help of artificial intelligence (AI)-based software that can automatically interpret ECGs with high accuracy.

The evolution of ECG machines has played a crucial role in diagnostic medicine by allowing doctors to better understand and interpret the electrical signals produced by heart contraction. ECG machines have come a long way since they were first invented over 100 years ago. They are now smaller, more portable, and easier to use than ever before. This continuous evolution has made them an invaluable tool for diagnosing cardiac conditions. It is evident that there will be more advancement coming our way. As technology becomes more sophisticated, who knows what else the next 100 years hold!”


The Evolution Of ECG Machines – BW Healthcare (businessworld.in)

Public Access Defibrillation Programs: Improving Outcomes Worldwide using Five Steps

Out of hospital cardiac arrest (OHCA) is one of the most frequent causes of death and leading cause of healthcare expenditures. This has led to significant research to study ways to reduce morbidity and mortality secondary to OHCA. The American Heart Association developed a campaign to improve awareness and outcomes of patients suffering an OHCA.

There were five areas they were looking to improve on what is referred as the chain of survival when it comes to OHCA’s.

  1. Immediate recognition of cardiac arrest and activation of the emergency response system
  2.  Early cardiopulmonary resuscitation (CPR) with an emphasis on chest compressions
  3. Rapid defibrillation
  4. Effective advanced life support
  5. Integrated post‐cardiac arrest care


In this study, they analysed the survival after ventricular fibrillation cardiac arrest in the Sao Paulo Metropolitan Subway System following the implementation of a targeted PAD (public access defibrillator) program. The program placed automated external defibrillators in railway stations and provided Heartsaver First Aid cardiopulmonary resuscitation (CPR) automated external defibrillator training and refresher courses for security officers. The Sao Paulo railway system carries approximately 4.5 million people which provided an optimum place to begin the roll out of the PAD program. The systems‐dedicated security officers and cameras allow for rapid recognition, CPR, and defibrillation.



Results showed that their data combined with prior studies which targeted PAD programs can be successful throughout the world. Increased advocacy is needed to establish more targeted PAD programs worldwide, along with programs to improve all parts of the chain of survival, in particular, public awareness of cardiac arrest and the need for rapid CPR administration.


Read full article in link below;


Public Access Defibrillation Programs: Improving Outcomes Worldwide – PMC (nih.gov)

Are there disparities in the location of automated external defibrillators in England?


Early defibrillation is an essential element of the chain of survival for out-of-hospital cardiac arrest (OHCA). Public access defibrillation (PAD) programmes aim to place automated external defibrillators (AED) in areas with high OHCA incidence, but there is sometimes a mismatch between AED density and OHCA incidence.

The study aimed to assess if there were any disparities in the characteristics of areas that have an AED and those that do not in England.

The results showed that in England, the AED’s seemed to be more accessible in more affluent areas of the country with a lower residential population density.


Read full study in link below;

Are there disparities in the location of automated external defibrillators in England? – PMC (nih.gov)


Getting R-AEDI to save lives in Singapore

Early cardiopulmonary resuscitation (CPR) and defibrillation prior to the arrival of emergency medical services can improve survival from out-of-hospital cardiac arrest (OHCA) with good neurological outcome. However, the rate of local bystander CPR is only 24.3% and bystander defibrillation 2.1%.

In 2015, the R-AEDI (Registry for AED Integration) initiative was started to improve OHCA survival rates. R-AEDI alerts volunteers to nearby OHCA cases via the myResponder mobile application. In 2015-2017, 7,682 AEDs were mapped and made accessible via this app. Comprehensive site inspections also resulted in fewer non-functional AEDs, as AED owners were educated on the importance of the maintenance of pads and batteries. The AED heat map allows us to identify areas that are lacking in or require improved public access AED coverage.

The online AED registry found in the myResponder app is useful to locate AEDs rapidly during OHCAs. More community education would improve the rate of bystander defibrillation.

Getting R-AEDI to save lives in Singapore – PMC (nih.gov)



Network of Automated External Defibrillators in Poland before the SARS-CoV-2 Pandemic: An In-Depth Analysis

Introduction: Sudden cardiac arrest (SCA), which causes more than half of all cardiovascular related deaths, can be regarded as a common massive global public health problem. Analyzing out-of-hospital cardiac arrest (OHCA) cases, one of the key components is automatic external defibrillators (AEDs). Aim: The aim of this study was to analyze the use and distribution of AEDs in Polish public places.

Materials and methods: The data were analyzed by using the Excel and R calculation programs. Results: The data represents 120 uses of automatic external defibrillators used in Polish public space in the period 2008–2018. The analysis describes 1165 locations of AEDs in Poland. It was noted that the number of uses in the period 2010–2016 fluctuated at a constant value, with a significant rise in 2017. When analyzing the time of interventions in detail the following was noted: the highest percentage of interventions was observed in April, and the lowest in November; the highest number of interventions was observed on a Friday, while the least number of interventions was observed on a Sunday; most occurred between 12:00 to 16:00, and least between 20:00 to 8:00.

Conclusions: The observed growth in the number of cases of AED use in public places is associated with the approach to training, the emphasis on public access to defibrillation, and, therefore, the growth of social awareness.

This study will be continued. The next analysis would include 2020–2022 and would be a comparative analysis with the current research.


Location of out-of-hospital cardiac arrests and automated external defibrillators in relation to schools in an English ambulance service region

Introduction: This study sought to identify the availability of automated external defibrillators (AEDs) in schools in the region served by West Midlands Ambulance Service University NHS Trust (WMAS), United Kingdom, and the number of out-of-hospital cardiac arrests (OHCA) that occurred at or near to schools. A secondary aim was to explore the cost effectiveness of school-based defibrillators.

Methods: This observational study used data from the national registry for OHCA (University of Warwick) to identify cases occurring at or near schools between January 2014 and December 2016 in WMAS region (n = 11,399). A school survey (n = 2,453) was carried out in September 2017 to determine the presence of AEDs and their registration status with WMAS. Geographical Information System mapping software identified OHCAs occurring within a 300-metre radius of a school. An economic analysis calculated the cost effectiveness of school-based AEDs.

Results: A total of 39 (0.34%) of all OHCAs occurred in schools, although 4,250 (37.3%) of OHCAs in the region were estimated to have occurred within 300 metres of a school. Of 323 school survey responses, 184 (57%) had an AED present, of which 24 (13.0%) were available 24 h/day. Economic modelling of a school-based AED programme showed additional quality-adjusted life years (QALY) of 0.26 over the lifetime of cardiac arrest survivors compared with no AED programme. The incremental cost-effectiveness ratio (ICER) was £8,916 per QALY gained.


ConclusionCardiac arrests in schools are rare. Registering AEDs with local Emergency Medical Services and improving their accessibility within their local community would increase their utility.