Using Device To Give CPR Does Not Improve Survival

The randomized study, conducted in five North American cities including Columbus, showed that victims of sudden cardiac arrest were more likely to be discharged alive from the hospital if they received manual cardio-pulmonary resuscitation (CPR) rather than CPR administered by the mechanical device.

Results of the study are published in the June 14 issue of the Journal of the American Medical Association.

Lynn White, clinical research manager in emergency medicine at Ohio State University Medical Center, coordinated the 34 medic crews involved in the Columbus study. “Everyone thought the device was a great idea and that its ability to provide compressions of much higher quality than those administered by humans would be lifesaving,” said White. “The results are certainly not what we anticipated at the onset of the study.”

The study involved 1,071 people who experienced out-of-hospital cardiac arrest in Columbus, Seattle, Pittsburgh, and Vancouver and Calgary, Canada. The study, originally planned to last 12-18 months, was halted in March 2005, nine months after it began, when it became apparent that the study device was not improving long-term outcomes.

The study device, the AutoPulse Resuscitation System, consists of a short backboard with a band fitted over the chest of the patient in cardiac arrest. At the push of a button, the band constricts the chest and delivers 80 compressions per minute.

In a controlled laboratory setting, the device produced greater blood flow to the heart and brain than manual CPR. But when deployed in real-life emergencies, as provided in the study, researchers found that patients were less likely to survive if they received compressions from the device. In the AutoPulse group, survival to discharge from the hospital was 5.8 percent, while survival to discharge in the manual group was 9.9 percent.

Michael Sayre, a physician in emergency medicine at Ohio State University Medical Center and principal investigator of the Columbus study site, said investigators involved in the study agree the idea of using devices to provide mechanical chest compressions should not be abandoned, but that further evaluation is needed, perhaps to improve design of the device or the way it is used.

“Given that so few people survive cardiac arrest, we need high quality research to learn how to save more lives,” said Sayre.

The study was sponsored by Revivant Corporation, now part of ZOLL Medical, maker of the AutoPulse Resuscitation Device used in the study. Revivant provided the $15,000 devices and funding for the study.