PITTSBURGH, July 27, 1998 — Police officers using automated external defibrillators (AEDs) to shock people in cardiac arrest, can have a significant impact on reducing deaths from out-of-hospital sudden cardiac arrest--the single leading cause of death in the United States--according to a study by emergency medicine physicians at the University of Pittsburgh Medical Center (UPMC).
The study found that whenever police were able to arrive prior to paramedics, people in cardiac arrest who were shocked by the police were nearly 10 times more likely to survive than those not shocked by police. The three-year study is published in the August 1998 issue of the Annals of Emergency Medicine.
The great majority of cardiac arrests occur out-of-hospital and are due to ventricular fibrillation in which the heart is quivering in an uncoordinated manner and is unable to effectively pump blood. The only treatment is electrically counter shocking, or defibrillating, the heart.
"For patients in cardiac arrest, time is the primary determinant of survival," said principal investigator Vince Mosesso, M.D., F.A.C.E.P., assistant professor of medicine in the UPMC’s department of emergency medicine, and chairman of the American Heart Association-Pennsylvania Affiliate’s AED Task Force. "The earlier this counter shock is given, the greater the likelihood of survival and the lesser the likelihood of neurologic damage. Police officers are ideal first responders since they often arrive at the scene of medical emergencies prior to emergency medical personnel."
An AED automatically determines whether defibrillation is necessary by performing a computerized analysis of the victim’s heart rhythm. The device warns all personnel to stand clear and notifies the user when the shock is to be delivered. The shock is delivered only if the first responder presses the appropriate button.
For the study, Dr. Mosesso, physicians from the Center for Emergency Medicine, and emergency medical services (EMS) personnel from suburban Pittsburgh communities trained, equipped and authorized 200 officers from seven suburban police departments to use AEDs to resuscitate people in cardiac arrest. The participating municipalities were: Baldwin Borough, Bethel Park, Castle Shannon, Dormont, Mt. Lebanon, South Park and Upper St. Clair. The EMS services involved were: Medical/Rescue Team South Authority, Tri-Community South EMS and Baldwin Borough EMS.
In each community, one police unit in each patrol zone was equipped with a defibrillator. All police officers in the study had a current certification in CPR and either American Red Cross First Aid or First Responder training. Each officer received four hours of training in the use of the device. Officers followed a strict protocol when using the defibrillator and only used the device prior to the arrival of an advanced life support EMS unit which then took charge of the patient's care.
During the study, police arrived before EMS personnel in more than 50 percent of the calls. When police delivered the shock, there was a 26 percent survival of patients versus 3 percent if they did not shock. Over the three-year period, police officers applied the AED to 69 percent of patients when they arrived prior to EMS and defibrillated 61 percent of those in ventricular fibrillation.
"An analysis of our data also reveals that police utilization of AEDs was the only independent predictor of survival to hospital discharge," said Dr. Mosesso. "It is important to note, however, that the effectiveness of AED use by police will be dependent on local issues such as assuring early police arrival at the scene and prompt use of the device."
Other investigators in the study were: Eric A. Davis, M.D., F.A.C.E.P., from Strong Memorial Hospital in Rochester, N.Y.; and Thomas E. Auble, Ph.D., research assistant professor; Paul Paris, M.D., F.A.C.E.P., professor and chairman of emergency medicine and Donald M. Yealy, M.D., F.A.C.E.P., vice chairman and associate professor of emergency medicine, all from the Department of Emergency Medicine at the University of Pittsburgh and the Center for Emergency Medicine.
The LIFEPAK 300 semi-automated advisory external defibrillator, made and provided by Physio-Control Corporation of Redmond, WA, was used to deliver the shocks.