In health care, we are trained not to rely on assumptions. We build systems that anticipate risk, standardize response, and make the next step clear before it is needed. When something goes wrong, we do not improvise. We follow a plan that already exists.

This is why it is so striking to encounter environments where safety depends almost entirely on assumption.

The tragic example of AED accessibility.

I began thinking about this outside of health care. I came to this through someone I know, John Ellsessar, whose life has been shaped by loss. His son, Michael, died at 16 after suffering sudden cardiac arrest on a high school football field where an AED was not immediately accessible.

That experience changed what he did next. It also changed how I think about a question that often goes unasked: What is the plan when something goes wrong?

Consider sudden cardiac arrest. It is one of the few situations in medicine where the response is both straightforward and time-dependent.

When John explained it to me, he put it simply: A heart attack is a plumbing problem, a blocked artery.
Sudden cardiac arrest is an electrical problem. The heart’s rhythm stops. For cardiac arrest, the only effective treatment is immediate CPR and rapid defibrillation.

Survival decreases by roughly 7 to 10 percent with each minute that passes without defibrillation. When an AED is used within the first few minutes, survival rates are significantly higher. After 10 minutes, survival becomes far less likely.

Time is not theoretical. It is decisive. And yet, in many community settings, access to that response is not consistently operationalized.

In Massachusetts, most schools now have AEDs. But ownership is not the same as access. A device may be present but locked inside a building, located far from an athletic field, or unavailable after hours. In those moments, the difference between having a resource and being able to use it becomes very real.

Some communities still lack access altogether. One nonprofit organization, Scholastic Sports Zone Foundation, has already donated more than 80 AEDs across Massachusetts to schools and community programs that did not previously have them or needed additional devices to improve access. The need is not theoretical. It is visible.

Through John Ellsessar’s advocacy, Massachusetts passed Michael’s Law, strengthening cardiac emergency preparedness in schools. It is a clear example of what can change when assumption is no longer accepted.

I have seen a version of this in my own work. In a health care setting, distance and layout can affect how quickly emergency equipment can be reached. Through a grant, we added additional AEDs so that access better matched the time-sensitive nature of cardiac arrest. The device was already part of the system, but expanding access improved how quickly it could be reached in an emergency.

Recognizing a system gap.

What is often missing is not willingness. It is structure.

In health care, we would recognize this immediately as a system gap. An intervention is not considered available if it cannot be accessed within the timeframe required. Outside of health care, that expectation is less consistently applied.

John said something that has stayed with me: Fire extinguishers are everywhere. Fire extinguishers save things. AEDs save humans. We would never accept a school without fire extinguishers. Why would we accept one where the AED is inaccessible?

The comparison is clear. We have normalized preparation for protecting buildings. We have not consistently done the same for protecting people.

Safety that depends on assumption is inherently variable. In practice, variability is where risk lives. In patient safety, harm often occurs when a known risk meets an unclear or inaccessible response.

Nurses know not to trust assumptions.

What nursing brings to these situations is clarity about what it takes to respond: access, timing, roles, and sequence. Not just whether something is present, but whether it can be used, by whom, and how quickly.
It is the same thinking that drove John to move beyond questions and help change how communities prepare for cardiac emergencies.

But this is not only a nursing question. It is a question for anyone responsible for a child, a team, a school, or a community space.

If something happens, what exactly is the plan? Where is the AED? Who can get it? How long will it take? Those answers should not be uncertain. They should be known. Because safety is rarely determined in the moment it is needed. It is determined in the planning that came before.

Courtney Desy, BSN, RN, OCN, is an oncology infusion nurse. She cares for adults receiving chemotherapy and immunotherapy and is the founder of the Stronger Than Chemo Foundation, a nonprofit focused on improving patient education and support during cancer care. Her last post on AJN Off the Charts was “Beyond ‘This Is How We Do It’: Teaching Nurses to Think Critically About Practice.”

Illustration generated using Google’s Nano Banana 2.

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