Researchers at the University of Washington (Seattle, USA), the London Ambulance Service (United Kingdom), and other institutions conducted a multicenter, randomized trial of dispatcher instructions to bystanders performing CPR on patients 18 years of age or older with out-of-hospital cardiac arrest. The patients (and the responders) were randomly assigned to undergo chest compression alone or chest compression plus rescue breathing, with CPR instructions relayed from the dispatchers to the bystanders. The primary outcome was survival to hospital discharge; secondary outcomes included a favorable neurologic outcome at discharge.

The results showed that of the 1,941 patients who met the inclusion criteria, 981 were randomly assigned to receive chest compression alone and 960 to receive chest compression plus rescue breathing. The researchers observed no significant difference between the two groups in the proportion of patients who survived to hospital discharge (12.5% with chest compression alone and 11% with chest compression plus rescue breathing), or in the proportion who survived with a favorable neurologic outcome. Subgroup analyses showed a trend toward a higher proportion of patients surviving to hospital discharge with chest compression alone, as well as for those with shockable rhythms. The study was published early online on July 29, 2010, in the New England Journal of Medicine (NEJM).

"Dispatcher instruction consisting of chest compression alone did not increase the survival rate overall, although there was a trend toward better outcomes in key clinical subgroups,” concluded lead author Thomas Rea, M.D., of the University of Washington, and colleagues. "The results support a strategy for CPR performed by laypersons that emphasizes chest compression and minimizes the role of rescue breathing.”

The findings concur with the science advisory statement from the American Heart Association (AHA) published in 2008, recommending compression-only CPR by bystanders who are not adequately trained, or who feel uncomfortable with performing rescue breathing on other adults who collapse from sudden cardiac arrest.

Related Links:
University of Washington
London Ambulance Service