In the largest study of its kind to date, researchers reported that cardiac arrest victims fare better when first responders and paramedics pause to give rescue breaths during CPR.
The finding comes as a surprise given that other recent research has supported the increased use of continuous chest compressions for out-of-hospital cardiac arrests.
The study, published this month in the New England Journal of Medicine, was selected as one of the top 10 research advances in 2015.
The new study follows the release of updated resuscitation guidelines issued in October by the American Heart Association that recommend interrupted chest compressions, which are a sequence of 30 compressions followed by two rescue breaths.
However, the recommendations also allow an option not to interrupt chest compressions for breaths, said Clifton Callaway, M.D., Ph.D., one of the study’s investigators and chair of the committee that wrote the AHA guidelines.
Research out of Arizona seemed to show survival from cardiac arrest is higher when first responders and bystanders skip rescue breaths.
“They implemented that in Arizona and other regions, and saw an increase in survival,” said Callaway, a professor of emergency medicine at the University of Pittsburgh.
The group writing the CPR guidelines took those findings into consideration and noted that although the preference is for interrupted chest compressions, it’s reasonable for bystanders and trained providers to use continuous compressions.
Perhaps that should be reconsidered, given the new study’s findings, Callaway said.
In the study of nearly 24,000 patients, about half received interrupted chest compressions and half received continuous chest compressions.
The type of CPR didn’t notably impact survival or neurologic function among out-of-hospital cardiac arrest patients, researchers found. In the continuous chest compression group, 9 percent of patients were discharged from the hospital and able to function, compared with 9.7 percent who received interrupted chest compressions.
But the type of CPR did appear to make a difference in other important ways, including whether a patient died on the scene.
“Patients who were getting continuous chest compressions were less likely to be taken to the hospital, which means they were more likely to die on the scene,” Callaway said.
“And if you look at people who died in the hospital and people who got discharged from the hospital, the group with 30 compressions and two breaths were spending more time surviving outside the hospital than the group who got continuous compressions,” he said.
Overall, the results favor the 30-compression, two-breath approach, said Callaway.
Even so, because the new study looked only at CPR provided by EMS, it’s unlikely the findings will impact the current recommendation for bystanders who don’t want to give mouth-to-mouth rescue breaths to perform compression-only CPR, he said.
“Compressions without breaths are definitely better than nothing at all,” Callaway said.
About 356,000 Americans experience cardiac arrest outside of a hospital each year, and only about one in 10 survive.
These latest findings highlight the need for continued CPR research, even when recommendations appear to be correct, Callaway said.
“When we go out and test what we think will be better, sometimes the effects are not what we expect,” he said. “It’s important to do the actual rigorous study to see if what we’re doing is actually a good idea.”