A recent observational study indicates that the initial placement of defibrillator pads by responders can significantly impact the chances of restoring spontaneous blood circulation after a defibrillation shock.
Joshua Lupton, M.D., has no recollection of experiencing cardiac arrest in 2016, but he is aware that first responders saved his life by delivering a defibrillator shock, which ultimately allowed him to make a full recovery. He is among the lucky fewer than 10% of individuals nationwide who survive a cardiac arrest outside of a medical facility.
He credits his survival to the quick defibrillation he received from first responders, although not everyone is as fortunate.
As the main author of a new observational study published in the journal JAMA Network Open, he, along with co-authors from Oregon Health & Science University, suggests that the initial positioning of the two defibrillator pads on the body could significantly affect the return of spontaneous blood circulation following a shock from a defibrillator.
“The shorter the duration of cardiac arrest, the better the outcome,” said Lupton, who serves as an assistant professor of emergency medicine at the OHSU School of Medicine. “If your brain is deprived of blood flow for too long, your chances of a positive outcome diminish.”
The researchers analyzed data from the Portland Cardiac Arrest Epidemiologic Registry, which meticulously documented the pad placements from July 1, 2019, to June 30, 2023. For this study, they reviewed 255 cases treated by Tualatin Valley Fire & Rescue, focusing on instances where the pads were either positioned at the front and side or at the front and back.
The results showed that placing the pads at the front and back increased the odds of restoring spontaneous blood circulation by 2.64 times compared to positioning them on the front and side.
Traditionally, healthcare professionals have believed that the placement of pads — whether in the front and side or front and back — offers equal effectiveness during cardiac arrest. The researchers noted that while their study is observational and not a definitive clinical trial, the significance of promptly reviving the heartbeat suggests a potential advantage in using the front-back arrangement over the front-side method.
“The goal is to direct energy from one pad to the other through the heart,” explained senior author Mohamud Daya, M.D., who is a professor of emergency medicine at the OHSU School of Medicine.
By positioning the pads in front and back, they may effectively “sandwich” the heart, which could enhance the delivery of the electrical current to the organ.
However, this ideal positioning isn’t always practical. Factors such as excessive body weight or the patient’s positioning can make quick adjustments difficult.
“It may be challenging to reposition individuals,” stated Daya, who is also the medical director for Tualatin Valley Fire & Rescue. “Emergency medical responders can often manage it, but bystanders might struggle to move a person. Moreover, it’s critical to deliver the electrical shock as swiftly as possible.”
In this regard, pad placement is only one of many elements that contribute to the successful treatment of cardiac arrest.
Lupton not only survived his cardiac event but also completed medical school at the very hospital where he spent several days recovering in the intensive care unit — Johns Hopkins University in Baltimore. This experience inspired him to shift his research focus toward enhancing early care strategies for cardiac arrest patients.
The findings of the new study were unexpected for him.
“I was surprised to see such a substantial difference,” he remarked. “This discovery may encourage the medical community to invest in further research to explore this area more deeply.”
This research was funded by the Zoll Foundation under grant award 1018439; the Society for Academic Emergency Medicine Foundation, grant award RE2020-0000000167; and the National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health, award U24NS100657 and National Center for Advancing Translational Sciences, award UL1TR002369. The views expressed in the content are solely those of the authors and do not necessarily reflect the official opinions of the NIH.
