A nationwide bystander cardiopulmonary resuscitation (CPR) program in South Korea helped improve neurologic recovery after out-of-hospital cardiac arrest.

The effect was similar whether bystander CPR was performed with dispatcher assistance or with a competent person but no dispatcher assistant. For out-of-hospital cardiac arrests occurring in private settings, only bystander CPR with dispatcher assistance improved patients’ neurologic outcomes.

Lead researcher Young So Run, MD, DrPH, of National University Hospital Biomedical Research Institute in Seoul, South Korea, and colleagues published their results online in the Annals of Emergency Medicine.

“Bystander CPR is critical to improving notoriously low survival rates for cardiac arrest, but many people remain reluctant to provide it, possibly because they lack confidence about doing it properly,” Ro said in a news release. “Having a trained dispatcher on the phone talking a bystander through the process while an ambulance gets there made a huge difference in bystander participation. The quality control program for dispatchers helped increase the bystander CPR rate in that short time. In cases where out-of-hospital cardiac arrest occurred in private settings, having dispatcher support was essential to improved neurological outcomes.”

The researchers mentioned that approximately two-thirds of out-of-hospital cardiac arrests occur in private settings and have lower survival rates compared with those in public settings. They added that multiple bystanders are more likely to present in public settings.

In this cross-sectional study, the researchers used a nationwide prospective registry and identified 37,924 adults in South Korea who were treated with emergency medical services (EMS) after suffering an out-of-hospital cardiac arrest between 2012 and 2013. In 2011, South Korea established a quality assurance program for EMS for out-of-hospital cardiac arrest, severe trauma, acute MI and acute stroke.

Of the patients, 31.1 percent received bystander CPR with dispatcher assistance, 14.3 percent received bystander CPR without dispatcher assistance and 54.6 percent received no bystander CPR. Approximately 44.8 percent of the bystanders received CPR instructions from dispatchers.

From the first quarter of 2012 to the last quarter of 2014, the bystander CPR rate increased from 30.9 percent to 55.7 percent. The survival rates with good neurologic recovery were 4.8 percent among patients who received bystander CPR with dispatcher assistance, 5.2 percent among patients who received bystander CPR without dispatcher assistance and 2.1 percent among patients who received no bystander CPR.

When compared with no bystander CPR, the adjusted odds ratios for good neurologic recovery were 1.50 for bystander CPR with dispatcher assistance and 1.34 for bystander CPR without dispatcher assistance. The adjusted odds ratios were 1.58 and 1.28, respectively, for cardiac arrests in private settings and 1.41 and 1.37, respectively, for cardiac arrests in public settings.

A multivariable analysis found that patients who received bystander CPR were more likely to have good neurologic recovery compared with patients who did not receive bystander CPR. There was no difference in survival to hospital discharge between the groups.

The study had a few limitations, according to the researchers, including that they classified bystander CPR groups according to information that emergency medical technicians obtained from bystanders at the scene. The trial’s observational design also meant that confounding issues could have had an influence on the results. In addition, the EMS system in South Korea was different from North American or European models, which have advanced service levels.