Cardiac Arrest and Resuscitation: A Tale of 29 Cities

Eisenberg MS, Horwood BT, Cummins RO, Reynolds-Haertle R, Hearne TR Annals of Emergency Medicine 1980 Vol 19 Pages 179-186

To determine the reasons for differences in out-of-hospital cardiac arrest survival rates, the authors reviewed published peer-reviewed studies conducted from 1967 to 1988 on 39 EMS programs from 29 different locations in eight countries. All of the studies reviewed, reported outcome data on a minimum of 100 cases. These programs were grouped into five types of pre-hospital systems: three types of single response systems (basic emergency medical technician [EMT], EMT-defibrillation [EMT-D], and paramedic) and two double-response systems (EMT/paramedic and EMT-D/paramedic). Reported discharge rates ranged from 2-25% for all cardiac rhythms and from 3-33% for ventricular fibrillation. The lowest survival rates occurred in single-response systems and the highest rates in double-response systems, although there was considerable variation within each type of system. Hypothetical survival curves suggest that the ability to resuscitate is a function of time, type, and sequence of therapy. Survival appears to be highest in double-response systems because CPR is started early. Another major determinant is bystander CPR before EMT or paramedic arrival. High rates of bystander CPR obviously result in earlier initiation of CPR. The authors speculate that early CPR permits definitive procedures, including defibrillation, medications, and intubation, to be more effective. The authors go on to suggest that with the more advanced double-response systems, survival rates appear to plateau at approximately 25-30% for witnessed arrests in VF. A community survival rate of 30% in these patients should be the standard of excellence given current technology and unchangeable variables such as the percentage of witnessed cases, percentage of cases in VF, and realistic response times.