CPR using chest compression alone administered by bystanders to victims of cardiac arrest is associated with better survival than conventional CPR, a large prospective study found.
The five-year observational analysis of more than 4,000 out-of-hospital cardiac arrest cases found that patients were 60 percent more likely to survive when bystanders used the simpler hands-on method -- eliminating the need to interrupt chest compressions for mouth-to-mouth rescue breathing -- according to Dr. Bentley Bobrow of the Arizona Department of Health Services in Phoenix and colleagues.
The prospective study of cardiac arrest outcomes in Arizona was undertaken after a public awareness campaign was begun in 2005 to improve "dismal" survival rates and increase knowledge of hands-only CPR, Bobrow and colleagues wrote in the Oct. 6 issue of the Journal of the American Medical Association.
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And it appeared to work. Over the study period, the rate of bystander-administered CRP increased significantly -- and the number of cases in which compression-only CPR was used rose from less than one in five to three out of four cases, the investigators found.
The current study adds to increasing evidence that hands-only CPR is beneficial and it "really confirms the importance of minimizing interruption of chest compressions," Bobrow said.
The findings come just weeks after two large clinical trials reported that survival after both CPR methods was roughly equivalent.
For their study, Bobrow and colleagues analyzed 4,145 cases of out-of-hospital cardiac arrests between Jan. 1, 2005, and Dec. 31, 2009. Of those cardiac arrests, nonmedical bystanders gave conventional CPR in 666 cases, hands-only CPR in 849 cases, and no CPR in 2,900 cases.
Over the study period, the researchers found that the rate of any type of bystander CPR rose from 28.2 to 39.9 percent, an increase that was statistically significant, and the proportion of CPR using the hands-only method increased from 19.6 to 75.9 percent -- another significant hike.
One implication of the study, Bobrow said, is that widespread public knowledge and use of chest compression-only CPR "could save thousands of lives a year."
He and colleagues noted it would have been impossible to randomize the study, since the decision of what type of CPR to use was left to the discretion of the bystanders.
To eliminate the potential for ascertainment bias, Bobrow added that EMS personnel were specifically trained in documenting the presence and type of bystander CPR.
The survival benefit seen in the study was "modest," noted an accompanying editorial by Dr. David Cone of the Yale University School of Medicine.
However, Cone wrote that the finding was important because survival after out-of-hospital cardiac arrest "has remained dismally low despite decades of study."
In his editorial, Cone also noted that standard CPR and compression-only CPR are currently considered equivalent by the American Heart Association and that new guidelines expected soon will concur -- and may even establish hands-only CPR as superior for nonmedical bystanders.
For professionals, though, conventional CPR will continue to have a place, Cone wrote, because airway ventilation is important for some victims of cardiac arrest.