Sudden cardiac arrest kills an estimated 200,000 people a year in the United States, but many of those lives could be saved if ordinary bystanders simply performed CPR, a new study led by Duke Medicine shows.
The early application of cardio-pulmonary resuscitation (CPR) by an average person nearby, combined with defibrillation by firefighters or police before the arrival of emergency medical services (EMS), was the one intervention that substantially increased survival from cardiac arrest, according to findings reported by Duke researchers and colleagues in the July 21 issue of the Journal of the American Medical Association.
"We were surprised to learn that survival increased only for those who received bystander-initiated CPR, compared with those who did not receive bystander-initiated CPR," said lead author Carolina Malta Hansen, M.D., of the Duke Clinical Research Institute. "Also, patients who received bystander or first-responder CPR and defibrillation were more likely to survive compared to those who received CPR and defibrillation once EMS arrived. This suggests that the very earliest intervention is crucial, and is something anyone can do. It saves lives."
Hansen and colleagues analyzed data from 4,961 cardiac arrest cases in 11 North Carolina counties from 2010-13. The data was gathered through a national registry set up to track cardiac arrests that occur outside of hospitals. The registry includes information about the responses of bystanders, first responders (firefighters, police officers, lifeguards and others on the scene ahead of the ambulance), and EMS. It also tracks how well people fared.
The four-year time frame coincided with a North Carolina campaign to encourage bystanders to perform chest-compression CPR -- no need for mouth-to-mouth resuscitation -- and to use an automated external defibrillator while awaiting an ambulance.
The campaign, called The HeartRescue Project, also worked to improve the use of portable defibrillators, which are increasingly available in public places and can be used by laypeople and first-responders to shock a heart back into rhythm.
Among the North Carolina counties included in the Duke study, survival with good neurologic recovery improved by 37 percent over those four years.
The project included public training programs in defibrillators and compression-only CPR at schools, hospitals and major events such as the N.C. State Fair, plus additional instruction for EMS and other emergency workers on optimal care for patients in cardiac arrest.
During the time covered in the study, Hansen said, 86.3 percent of patients received CPR before EMS arrived, with 45.7 percent initiated by bystanders and 40.6 percent by first-responders. Throughout the study period, a significant increase occurred in the proportion of patients receiving bystander-initiated CPR, from 39.3 percent in 2010 to 49.4 percent in 2013.
The proportion of patients who received bystander-initiated CPR and who also were defibrillated by first-responders increased from 14.1 percent in 2010, to 23.1 percent in 2013. Bystander CPR coupled with a first responder applying defibrillation was associated with improved patient survival compared to situations where patients waited to receive EMS-initiated CPR and defibrillation.
Of 1,648 defibrillated patients, 53.9 percent were defibrillated before arrival of the EMS - 6.9 percent by bystanders and 47 percent by first-responders. First-responder defibrillation increased significantly from 40.9 percent in 2010 52.1 percent in 2013.
"During the past decade, there has been a focus on increasing bystander CPR," said senior author Christopher Granger, M.D., a professor of cardiology and director of the Cardiac Care Unit?at Duke University Medical Center.
"Our findings show that survival can be improved by strengthening first-responder programs and encouraging more bystander CPR," Granger said. "This program shows that state and national programs to improve care of cardiac arrest, with a focus on the community and emergency medical response, can save more lives."
In addition to Hansen and Granger, study authors from Duke include Kristian Kragholm; Clark Tyson; Lisa Monk; Matthew E. Dupre; Emil L. Fosbøl; James G. Jollis; Benjamin Strauss; and Monique L. Anderson; along with David A. Pearson of Carolinas Medical Center; Brent Myers of Wake County EMS; Darrell Nelson of Wake Forest University; and Bryan McNally of Emory University.
The study received support from The HeartRescue Project, which is funded by Medtronic Philanthropy.