HOW IS AED RESPONSE TIME DEFINED?

What does the term “AED response time” mean? The national AED Program Design Guidelines define an AED Response Time Objective as the maximum desired elapsed period from the time a suspected sudden cardiac arrest collapse is first reasonably recognized to the time defibrillation therapy is first delivered (Guidelines section 2.10). AED response time includes four distinct time allocation elements: sudden cardiac arrest recognition, request to retrieve an AED, retrieval of an AED and use of an AED (Guidelines section 3.4.2). In an actual cardiac arrest emergency, the total time for these combined activities is the AED response time.

WHAT IS A REASONABLE AED RESPONSE TIME OBJECTIVE?

How quickly should AED owners be expected to use an AED when the question comes up in negligence cases? The answer requires separating the science from the operational realities of having AEDs placed in non-medical settings.

It is certainly true that cardiac arrest survival rates are directly related to how quickly a defibrillator is used. Faster is clearly better from scientific and therapeutic perspectives. But if the science is the sole baseline for setting a legally accountable response time standard, then AED owners (and, by extension, emergency medical services systems) should be required to use an AED within 1-2 minutes. Virtually everyone would agree this is an unreasonable goal operationally and financially.

If 1-2 minutes is an unfair legally accountable response time standard, why is 3 minutes any less so? It seems this number is based purely on the science but without consideration of the many factors that impact actual AED response times in workplace and community settings. Here are some of those factors:

• Frequency: On a location-specific basis, sudden cardiac arrest occurs very infrequently. Most workplace and community settings can expect to see one event every 10-20 years.
• Environment: Workplace and community AED placements are in non-medical settings where healthcare is not a primary or even secondary activity.
• People: The people expected to respond to cardiac arrest emergencies are non-medically trained volunteer bystanders with no legal obligation to act and who may experience a situation like this perhaps once in their lives.
• Recognition: For volunteer lay bystanders, sudden cardiac arrest can be a difficult condition to quickly and accurately recognize. Very often, bystanders think of fainting, seizures and other conditions before considering cardiac arrest as a potential cause.
• Culture: The highly controlling medical model that emerged in the 1990s still permeates the workplace and community AED world. The true fire extinguisher model has not yet taken hold. As a result, many bystanders believe only formally trained people can retrieve and use AEDs. Unfortunately, many organizations have AED access and use policies that reflect this belief.
• Equipment: Many workplace/community AED programs don’t have enough AEDs even to meet fair response time goals. Remember, an AED can cover no more than 283,000 square feet (often less).
• Liability: Sadly, the fear of legal liability remains a significant reason there is an AED shortage and why many bystanders are reluctant to become involved in cardiac arrest emergencies, even when AEDs are nearby.

Given these factors, what is a workplace and community AED response time goal that properly balances the benefits of early defibrillation with the need to rationally manage the legal accountability risks of owning AEDs? The AED Response Time Guideline found in section 3.4.3 of the AED Program Design Guidelines suggests the following:

The AED Response Time Objective for each defined AED Response Zone (the area one AED can cover) should have the goal of delivering defibrillation therapy within five (5) minutes or less from the time sudden cardiac arrest is first reasonably suspected.

This 5-minute AED response time goal is consistent with the American Heart Association’s Emergency Cardiac Care Guidelines (2015), which note that cardiac arrest survival rates are highest when bystanders deliver CPR and defibrillation is attempted within 3-5 minutes (page S422) (the AHA does not publish or set AED program operational standards but it does publish science that can be considered when designing AED programs). A 5-minute or less target recognizes that AED programs rely on non-medical people, under no obligation to act, in a setting not primarily focused on emergency medical services. It also recognizes it is impossible to predict how lay bystanders will react when facing cardiac arrest emergencies.

A POLICY THAT PROTECTS ORGANIZATIONS FROM THE 3-MINUTE AED RESPONSE TIME TRAP

For organizations with AEDs, the best way to avoid the 3-minute AED response time trap is to have a written response time policy that incorporates the 5-minute target described above. This policy should also note that the organization’s AED response time objective is a performance goal and not a guarantee.

Keep in mind that an organization’s response time policy is one of many that impact actual response time, and all must be integrated together. Examples include policies relating to response zones, response teams, AED access and use authorization, and number and placement of AEDs, among others. If you need help fully designing your AED program and putting complete policies in place, let me know.

CLOSING THOUGHT

Let me be clear: AED programs should be designed to respond as quickly as is reasonably possible to sudden cardiac arrest emergencies. Nothing in this brief suggests otherwise. That said, risk management is an important goal of AED ownership, and avoiding the 3-minute response time trap is one key to managing risk. A 5-minute AED response time policy properly balances science, practical operations and legal accountability and is the right approach for successful AED programs.