Nursing doctoral student explores novel CPR technique
The concept of CPR is simple. To stay alive blood needs to be circulated around the body. That’s the heart’s job. When the heart stops working people can temporarily step in and fill that role with chest compressions. We’ve all seen it in hospital dramas or even in person.
But what if we’ve been doing it wrong? What if there is a better way?
That’s exactly what Dr. Zach Smith, an East Carolina University College of Nursing doctoral student in the Department of Nursing Science, is trying to determine.
Smith is a certified registered nurse anesthetist, which is important. He works at FirstHealth of the Carolinas in Pinehurst but is originally from California, by way of Florida for undergraduate schooling.
ECU nursing science doctoral student Zachary Smith is exploring a novel approach to CPR that may extend life-saving options for patients in surgical and critical care settings.
Both of his parents worked in operating rooms, and he shadowed them starting at 13.
“I was like, ‘I want to be here. I love the crew. I love how everyone works together. I love the environment.’” Smith said. “But you never want to do what your parents do. So I didn’t want to be a surgical tech.”
He didn’t want to be a surgeon, either. He wanted a life outside of work.
“That kind of left anesthesia at the head of the bed. I started shadowing anesthesiologists and perfusionists and looking at going that route, but I ended up getting a job in the ICU as a support technician and found out about CRNAs,” Smith said. “We refer to ourselves as the best-kept secret in the hospital.”
Smith said a large part of being a CRNA is playing the what-if game, spending 99% of the time where things are going well and planning for the 1% of sheer terror that can occur in the operating room. During one of those stretches early in his training, one of the patients was having surgery on his back. Smith asked himself, “What happens if they arrest right now? How do we do chest compressions? How do we do anything?”
He was told by his preceptor that there was another bed in the hallway. It would take a few minutes, but they would unplug the patient from all the machines and get him on his back to start chest compressions.
“That seemed like it would take a really long time,” Smith said. He followed up with some research and found that in the ’90s researchers had proposed prone CPR — chest compressions on the patient’s back rather than chest — just to circulate some blood while the process of getting the patient on their back took place.
“It takes about 13 seconds to rip the drapes down and start prone CPR, and it takes almost five minutes for typical CPR,” Smith said. “That’s five minutes with no blood flow. That’s not going to have a good result.”
The obvious challenge with studying CPR is that the technique is used to save lives in critical situations — you can’t just pause resuscitation to set up an experiment or experiment on a healthy person.
Prone CPR had been studied in recently deceased people in rare studies. Consenting patients who died in intensive care units had 15 minutes of supine CPR and then 15 minutes of prone CPR, with blood pressures tested to determine if the blood was being perfused throughout the body.
Smith learned that arterial blood pressures were actually higher with prone rather than traditional CPR. But why?
He believes it comes down to how the body reacts to the physical act of chest compressions. In traditional CPR — a violent affair in any case, he said — the abdomen is pushed out and intra-abdominal pressure is lost. In prone CPR, the abdomen has nowhere to go, so the pressure stays higher in the abdomen, and in turn the chest cavity. In theory the retention of those pressures should translate to at least the same arterial pressures as with traditional CPR — probably greater.
“That’s what I’m looking at, trying to explain those physiological mechanisms,” Smith said.
Another reason challenge with traditional CPR is the potential for broken bones. In the 1960s, some experts advocated against CPR due to the possibility of cracking ribs that could puncture internal organs. But with prone CPR, the bones in the back are tougher.
“You’re getting the same basic chest compression, but the ribs to the spine are a lot stronger than the sternum to the ribs, so we’re not seeing as much of those fractures,” Smith said.
Prone CPR is still rather niche, Smith said, but the technique has caught on since the COVID-19 pandemic. Critical patients were having lung issues, which improved in the prone position.
“Because they were critical, we also saw a lot more patients suffering cardiac arrest while prone. Although my study is going to be intraoperative, this is something that affects ICU nursing and other ICU specialties as well,” Smith said.
The Study
The mechanics of the study Smith has designed are simple.
“I’m putting catheters in the abdomen, inside the chest cavity and inside the carotid artery to measure their blood pressure, and then comparing all three of those pressures between prone and traditional CPR to see if I can actually explain the mechanism,” Smith said.
The study is tricky for a number of reasons. It would be very difficult, if not impossible, to find living patients for the study so he’s employing bodies donated to science. But the window of time available to use those cadavers is very small.
With help from friends at an anesthesia program at Middle Tennessee School of Anesthesia, he has secured funding for two cadavers from the American Association of Nurse Anesthesiology, to have each serve as controls against the other. Smith will need to be ready at a moment’s notice to travel once they become available.
The only exclusion criteria Smith has for the donated bodies is for them to not have had previous cardiothoracic surgeries, for obvious reasons, or significant physiological deviations from the norm.
Smith recognizes that prone CPR is probably not going to take the place of the traditional method, but if his hypothesis holds there may be ways to improve it.
“If higher intra-abdominal pressures make thoracic compressions better, we might start looking at doing abdominal binding,” Smith said. “You might have somebody do abdominal counterpressure, or some sort of binder over the abdomen, to increase those intra-abdominal pressures.”
This isn’t a novel idea. An older technique — abdominal counter pulsation CPR — saw one person compress the chest and another the abdomen, opposite of each other. In a hospital setting this method could work well; in a restaurant, movie theater or at home, simpler is better. Recent changes to rescue CPR have even done away with rescue breathing for the sake of simplicity.
“There is this adage with chest compressions that even bad CPR is better than no CPR. I think that that’s how prone CPR started,” Smith said.
Smith hopes graduate in December, an ambitious proposition he acknowledges, and get his research findings out to the clinical community quickly. He lauds ECU’s relatively uncommon DNP to Ph.D. program for giving him the opportunity to bridge scientific discovery and hands-on practice.
“I want to continue that bench-to-bedside approach, to come up with the new data and translate it to clinical practice itself,” Smith said.
The Importance of Nursing Research
Dr. Linda Bolin, chair of the Department of Nursing Science and Smith’s dissertation chair, said a dedicated research program in any nursing school with a Ph.D. program is essential because it provides the structure, resources and culture necessary to develop nursing scientists and advance the discipline.
“It is difficult to be a sole researcher on an island by yourself,” Bolin said. “We need a continent that allows for a supportive environment of mentorship networking that helps students socialize into the role of a nurse scientist rather than functioning in isolation. Our program also fosters collaboration, interdisciplinary and intellectual community, which is so important for the beginning nurse scientists in our program.”
Nursing research directly informs patient care, health systems and policy, Bolin said, of which Smith’s research focus is an excellent example. Bolin believes a dedicated research program is not just beneficial, but it is foundational and essential for the long-term health of the nursing profession.
“As a practicing CRNA, he was exposed to a clinical issue, patients in the operating room in need of prone CPR, and wanted to explore this more, which is why he enrolled into our Ph.D. program,” Bolin said. “A dedicated program such as ours ensures that research efforts are strategic and aligned with current health care needs, which allow for meaningful translation into practice.”