Page 49 - Occupational Health & Safety, January/February 2019

DEFIBRILLATORS & CPR
A New Model for Increasing Cardiac Arrest Survival RequiresWeFixtheNationalAEDShortage,Too
The obvious reason for the AED shortage is the fact these life-saving devices are, with a few exceptions, not legally required at most locations. But voluntary deployments are clearly not getting the job done on their own.
BY RICHARD A. LAZARThis is the second in a series of articles on the state of affairs in public access automated external defibrillators (AEDs) and the chal- lenges and opportunities we face in deploy- ing them for optimum community preparedness. For the first, see “Squad Goals: Moving the Needle on Sudden Cardiac Arrest Requires a New Model.” (Oc-
tober 2018 OH&S).
In the previous article in this series, we discussed
that sudden cardiac arrest (SCA) is the third-leading cause of death in the United States and one of the most challenging public health issues to address. Sad- ly, less than 6 percent of SCA victims survive, despite 30 years of effort to combat this scary statistic. We know that CPR and the use of an AED soon after SCA occurs are the keys to saving more lives. Yet, today, only one in four people who experience SCA get by- stander CPR, and fewer than four in 100 benefit from bystander use of an AED.
So, while device makers innovate the AED tech- nology and community leaders increase SCA aware- ness, why haven’t we made more progress? The big- gest reason is the scarcity of these life-saving devices in public places throughout the country. As AEDs have become more commonplace, many believe they can be found “everywhere.” But the truth is, because of an AED shortage in the United States, most SCA victims experience their life-or-death emergency where no AED can be found. The solution? We must have a clearer understanding of the magnitude of the problem and then concerted public policy action by policymakers, thought leaders, national advocacy or- ganizations, SCA survivors, victims’ families, and oth- ers who care to effect positive change.
Quantifying the AED Shortage
The AED shortage can best be understood as a math problem. Using the key variables explained below, we can calculate how many AEDs are needed to cover a given area. Comparing this number to the number of AEDs currently available helps shed light on the critical gap.
AED Response Time: Time is the most critical factor to survival. In fact, the time it takes to deliver the first AED shock has a direct effect on the chances an SCA victim will survive at all. Longer times to de-
fibrillation equal lower survival rates. In non-medical settings such as health clubs, shopping malls, retail stores, government and office buildings, schools, and similar locations, it is reasonable to expect that AEDs should be used within four to five minutes from the time SCA is first recognized. This concept of “AED response time” refers to the time it takes someone to recognize SCA (not an easy thing for volunteer by- standers), start CPR (which requires bystanders to be willing and at least minimally trained), tell people nearby to call 911 and retrieve an AED (assuming other people and an AED are available), and apply and use an AED.
Beware the AED Response Time Trap: Many wrongly suggest that public access AED programs should enable lay responders to retrieve and use AEDs within three minutes of recognizing SCA. The fact is, most bystander AED programs cannot consistently meet this three-minute response time target (actually, neither can most professional medi- cal environments). We shouldn’t put AED owners in legal jeopardy by imposing an unreasonable and mostly unachievable AED response time objective. Rather, a four to five minute organizational response time policy properly balances the benefits of early defibrillation with the need to rationally manage the legal accountability risks of owning AEDs. You can read more about this in How to Avoid the 3-Minute AED Response Time Trap. (http://www.readisys.com/ avoid-the-3-minute-aed-response-time-trap/)
AED Retrieval Time: Because of time consid- erations, AEDs can cover only a limited geographic area. Given the known time constraints associated with treating SCA, we can calculate the area a single AED can cover within a four to five minute AED re- sponse time goal.
Factors impacting an AED’s coverage area include time, distance, and obstacles. Generally, two minutes of the AED response time are allocated to AED re- trieval. On average, adults walking rapidly can travel approximately 300 feet per minute. At 300 feet per minute, it will take up to one minute to reach the AED and another minute to return to the person hav- ing SCA. So we use a 300-foot radius to calculate the maximum potential AED coverage area that will al- low an AED retrieval time of up to two minutes.
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