Bystander CPR is a critical link in the chain of survival. It has been shown to more than double a victim’s chance of surviving an out-of-hospital cardiac arrest (OHCA).1 Using an automated external defibrillator (AED) in addition to performing bystander CPR further improves the chances of survival.2 Yet, both bystander CPR and AEDs are not provided in a majority of OHCA events.1,2

 

Because time is so critical in cardiac arrest, immediate bystander action (calling 9-1-1, performing CPR, and early defibrillation) is the cornerstone of maximizing the effectiveness of subsequent EMS and hospital interventions and ultimately survival. This is especially true in rural and congested urban areas with prolonged response times. 

 

Bystander CPR lengthens the duration of ventricular fibrillation (VF) and provides critical blood flow to the heart and brain during cardiac arrest.3 This improves the likelihood of shock success, return of spontaneous circulation (ROSC), survival, and the chance of a good functional outcome.3,4 The combination of quickly calling 9-1-1, immediately doing chest compressions and applying an AED as soon as possible works synergistically to increase survival. Each of the successive links in the chain of survival depends on the preceding links—the whole is greater than the sum of the parts.

 

Because of this, EMS (in fact, our entire healthcare system) has a vested interest in the delivery of care before the arrival of professional rescuers on scene. Everything EMS does to improve the readiness of lay rescuers (training, public awareness, 9-1-1 pre-arrival instruction, assistance locating AEDs, etc.) will pay heavy dividends in an increased survival rate in our communities.

 

Measuring Interventions

There is wide and unacceptable variability in cardiac arrest outcomes between communities,5 which likely results from differences in implementation and performance of important interventions such as 9-1-1 pre-arrival CPR instructions, bystander CPR and early defibrillation. Continuously measuring these interventions and analyzing their impact is the only way to know specifically what needs improvement and whether a system is functioning as intended.

 

Current registries exist to help communities measure their cardiac arrest incidence and outcomes. The CARES (Cardiac Arrest Registry to Enhance Survival; https://mycares.net) registry is a national data collection system for OHCA. This registry includes data collection on OHCA incidence and process of care, including bystander CPR, AED use and, recently added, data for 9-1-1 pre-arrival CPR instructions.

 

The need to take this a step further and systematically track data from 9-1-1 centers has come about due to the realization that the quality of telephone CPR instructions has a significant impact on survival. Details such as whether the cardiac arrest was correctly identified, whether CPR instructions were provided, how long into the 9-1-1 call before CPR was started, and what type of CPR was given can make the difference between life and death. There is growing interest in pre-arrival CPR metrics and the need to quantify this critical intervention. To illustrate the point: If the 9-1-1 system provides pre-arrival CPR instructions at eight minutes into a call, it will obviously have much less impact on survival than if the instructions were provided one minute into the call. And yet both callers received “pre-arrival CPR instructions.”

 

The state of Arizona and King County, Wash., have  piloted a data collection tool and reporting system for suspected cardiac arrest dispatch calls, which is integrated into their OHCA registries and linked to EMS care, hospital care and patient outcomes. In Arizona, the 9-1-1 pre-arrival CPR program is part of the Save Hearts in Arizona Registry and Education (SHARE) Program, a collaboration between the Arizona Department of Health Services and the University of Arizona (see http://azdhs.gov/azshare/911/index.htm). The Arizona and King County, Wash., models have now been incorporated into CARES to help dispatch and EMS systems across the country. 

 

Why You Need an AED Registry

Like bystander CPR data, AED information is a critical component of an ongoing cardiac resuscitation system of care. When various data points along the continuum of care (bystander CPR, 9-1-1 data, AED placement/use, and outcomes) are integrated into a standardized registry, such as CARES, an entire system can be measured and improved over time.

 

AED information needs to be integrated into registries in order to know where AEDs are placed, if they are checked for maintenance (pads, batteries), if potential users are trained on-site, when they are used, and the ultimate patient outcome. Event data should include the location of the arrest, who did CPR, what kind of CPR was performed, who applied the AED, and whether a shock was delivered. Detailed data after an AED is used should be made available to other healthcare providers such as emergency physicians and cardiologists.

What follows is a closer examination of why you need an AED registry: 

 

• You can’t use them if you don’t know where they are: We know AEDs are extremely safe and effective.2 We also know they are only used by the public in approximately 4% of OHCAs.6 Knowing where AEDs are located and if they are being used is important information. For example, if AEDs are placed in a certain area of town but they aren’t being used in cardiac emergencies, likely more public education is needed. In contrast, if cardiac arrest is occurring more frequently in a certain location where few AEDs are available, then more attention should be given to acquiring and placing additional AEDs throughout that community.

• You can’t use them if they’re not maintained: Just as an AED that is not found cannot save a life, neither will an AED that is not properly maintained. Maintenance includes making sure expired pads and batteries are replaced and software upgrades are installed. A Web-based AED registry can assist in ensuring the functionality of AEDs by sending maintenance reminders. Just as fire departments check fire extinguishers in a community, it makes sense that you need to have a system to ensure that all AEDs are maintained in a ready-to-use state.

• You can’t use them if they’re not there: Another reason for having an AED registry is the fact that the information can be useful in the submission of grants for the deployment of additional AEDs. To secure and receive either private foundation or government grants, a Public Access to Defibrillation (PAD) program needs accurate data—both utilization and patient outcome information. AED grants can come from both private foundations and government. An example of a private foundation offering grants is The Ramsey Social Justice Foundation (http://ramseyjusticefoundation.org), which has donated AEDs to communities participating in the SHARE Program in Arizona. An example of a government AED grant is the one offered through the U.S. Department of Health and Human Services’ Rural Health program. 

 

Finding AEDs with Social Software

Keeping tabs on the locations of existing AEDs has been a challenge. There have been several large-scale efforts to locate AEDs within communities. One such program in Philadelphia used a crowdsourcing approach. In 2012, the MyHeartMap Challenge (www.med.upenn.edu/myheartmap) set up a competition and offered monetary awards for those submitting the most AED locations. Using a smartphone application, participants photographed and recorded GPS coordinates for AEDs they found throughout the city. 

 

Also using mobile phone technology, the PulsePoint App (http://pulsepoint.org) takes locating AEDs one step further—tying the location of the AEDs directly to nearby cardiac arrest incidents through the community’s 9-1-1 system. The mobile app (iPhone and Android) sends real-time AED location information to those within a certain radius of a suspected cardiac arrest with the goal of increasing both bystander CPR and the use of the life-saving devices. 

 

Potential lay rescuers must normally witness an arrest to take action. PulsePoint seeks to improve the efficiency of both CPR-trained citizens and publicly available AEDs by making bystander rescuers aware of cardiac events occurring nearby so they can retrieve an AED and begin CPR while paramedics are making their way to the scene. No one is in a better position to make a difference in the first few minutes of an OHCA than a nearby CPR/AED-trained individual. PulsePoint has been successfully implemented in many U.S. cities.

 

Disparity Issues: Location of Arrests

The location of a cardiac arrest has a significant influence on patient survival. Patients who arrest in public have a higher probability of having their arrest witnessed, receiving bystander CPR, and receiving defibrillation with an AED—all of which strongly increase the chance of survival.2

 

National data on bystander CPR and PAD programs have uncovered large and unacceptable disparities. For example, using the CARES registry, Sasson and colleagues found that in low-income black neighborhoods the odds of receiving bystander-initiated CPR was approximately 50% lower than in high-income non-black neighborhoods.7 Their study showed that both the racial composition and the median income of a neighborhood have a significant effect on the likelihood of receiving bystander CPR. Studies like this help identify where to concentrate public training and education efforts.

 

In Arizona, Dr. Sungwoo Moon (a visiting professor from Korea University) found OHCA victims in mainly Hispanic neighborhoods received bystander CPR less frequently and had worse neurologic outcomes than those in mainly white, non-Hispanic neighborhoods.8 

 

Using Geographic Information System (GIS) technology and SHARE Program OHCA event data, Dr. Moon was also able to identify the areas where OHCAs occurred most frequently but where AEDs were lacking. This is a great example of how important it is to have both cardiac arrest event and AED location data.9

 

A Variety of AED Registries

AED registries can take different shapes. Most states require reporting of AED locations to local EMS and/or dispatch centers. However, it varies widely as to how agencies capture and actually use this information. 

 

Arizona’s SHARE Program AED registry is voluntary; however, it fulfills the statutory requirement that AED owners enter into an agreement with a physician to oversee a PAD program. In the SHARE registry, medical direction is free of charge to those complying with the training and reporting requirements. The registry uses a Web-based data entry system.

 

AED owners must keep their units functioning and registries can play an important role in helping to ensure that AEDs are always in a ready-to-use state. A Web-based AED registry can send general reminders to registrants or targeted reminders based on expiration dates entered into the system. Several companies offer subscription services to assist with this.

 

The Future of AEDs

Tracking AEDs that are placed in static locations is one thing; however, tracking the location of AEDs that are mobile, such as those used during high school athletic events, requires a higher level of sophistication. Also, many AEDs are moved from one “permanent” location to another. In the future, AEDs will include technology (perhaps GPS, WiFi, Bluetooth, or other methods) that will allow tracking in real time, thereby allowing more efficient monitoring of the units’ placement and readiness. This technology will likely be integrated into CAD systems in the future, aiding dispatchers in locating AEDs and relaying that information to callers, in an effort to increase AED use. And of course, more AED use and more bystander CPR will translate into more lives saved.

 

References

1. Sasson C, Rogers MA, Dahl J, et al. Predictors of survival from out-of-hospital cardiac arrest: A systematic review and meta-analysis. Circ Cardiovasc Qual Outcomes. 2010;3:63–81.

2. Hallstrom AP, Ornato JP, Weisfeldt M, et al. Public-access defibrillation and survival after out-of-hospital cardiac arrest. N Engl J Med. 2004;351:637–646.

3. Eftestol T, Wik L, Sunde K, et al. Effects of cardiopulmonary resuscitation on predictors of ventricular fibrillation defibrillation success during out-of-hospital cardiac arrest. Circulation. 2004;110:10–15.

4. Bobrow BJ, Spaite DW, Berg RA, et al. Chest compression-only cpr by lay rescuers and survival from out-of-hospital cardiac arrest. JAMA. 2010;304:1447-1454.

5. Nichol G, Thomas E, Callaway CW, et al. Regional variation in out-of-hospital cardiac arrest incidence and outcome. JAMA. 2008;300:1423–1431.

6. Weisfeldt ML, Sitlani CM, Ornato JP, et al. Survival after application of automatic external defibrillators before arrival of the emergency medical system: Evaluation in the resuscitation outcomes consortium population of 21 million. J Am Coll Cardiol. 2010;55:1713-–1720.

7. Sasson C, Magid DJ, Chan P, et al. Association of neighborhood characteristics with bystander-initiated cpr. N Engl J Med. 2012;367:1607–1615.

8. Moon S, Kortuem W, Kisakye M, et al. Disparities in Bystander CPR and Neurologic Outcomes from Cardiac Arrest According to Neighborhood Ethnicity Characteristics in Arizona. Poster presentation to the American Heart Association, Resuscitation Science Symposium, Scientific Sessions in Dallas, Texas. November 2013. Circulation; in press.

9.  Moon S, Kortuem W, Kisakye M, et al. Analysis of Out-of-Hospital Cardiac Arrest Location and Public Access Defibrillator Placement in Metro Phoenix, Arizona. Poster presentation to the American Heart Association, Resuscitation Science Symposium, Scientific Sessions in Dallas, Texas. November 2013. Circulation; in press.