by It is no exaggeration to say that knowing how to use a defibrillator properly can save someone’s life. A new study suggests that one specific approach to electrode placement is significantly more effective when it comes to getting the heart beating again.
According to a team of researchers led by Oregon Health and Science University (OHSU), placing one pad on the chest and one on the back of the person in cardiac arrest induces return of spontaneous circulation (ROSC) 2 .64 times more likely than if the pads were placed on the front and side.
That’s based on an analysis of 255 incidents attended by the Tualatin Valley Fire & Rescue team in Portland, between July 2019 and June 2023. The chest and back position (anterior-posterior or AP) was used in 158 people, and the chest – and lateral position On the remaining 97 occasions, the position (anterior-lateral or AL) was used.
“I didn’t expect to see such a big difference,” said Joshua Lupton, an assistant professor of emergency medicine at OHSU. “The fact that we did that might light a fire in the medical community to fund some additional research to learn more.”
The AP positioning is not a new idea, and both AP and AL are used regularly by medical professionals. Although AP is commonly prescribed to infants, the AL approach is the approach most people will be familiar with for fibrillating adults – and there has been very little research into which option is most effective.
Studies have examined the differences between AP and AL when the two approaches are used in the context of treating persistent atrial fibrillation (an abnormal heart rhythm). AP also comes out on top here.
The idea is that the AP placement effectively clamps the heart between the two electrodes, making it more likely to respond to the resulting electric shock because more electricity reaches the heart.
“The key is you want energy to move from one pad to the other through the heart,” says Mohamud Daya, a professor of emergency medicine at OHSU.
There are some limitations worth noting: this was an observational study and not one conducted under more stringent, clinical conditions, meaning other factors may have played a role in the varying recovery rates. Furthermore, the AL placement is often easier to apply than AP.
Furthermore, AP or AL positioning only made a difference in getting the heart beating again. That difference disappeared when it came to the number of people who recovered to be discharged from the hospital.
That highlights how pad placement is just part of a bigger picture when it comes to recovery. But since only about 1 in 10 people survive out-of-hospital cardiac arrest, anything that could improve that figure should be worth investigating.
“The less time you have in cardiac arrest, the better,” says Lupton. “The longer your brain has low blood flow, the lower your chances of a good outcome.”
The research was published in JAMA network opened.
