Reconsidering EMS Response Criteria

I thought I was witnessing a revolution. The 2007 Consortium of U.S. Metropolitan Municipalities’ EMS Medical Directors (also known as the Eagles) issued an evidence-based EMS benchmarking model that eliminated ALS response interval. They noted that much of the clinical research used to establish acceptable ALS response time intervals was conducted prior to the widespread dissemination of AEDs and at a time in which the compression component of CPR was not emphasized as it is now.

They proposed that EMS systems focus attention to first response/BLS response time to measure

… the most important predictive elements for optimal outcome: time elapsed until initiation of basic chest compressions and time elapsed until defibrillation attempts.

That change did not happen, but we need to reconsider what the Eagles advocated.

8:59 minute response criteria started in Seattle

The 1979 “Cardiac Arrest in the Community” paper in the Journal of the American Medical Association made this observation; If CPR was initiated within four minutes and if definitive care was provided within eight minutes, 43% of the patients survived. If either time was exceeded, the chances of survival fell dramatically. This document appears to be the foundation of the requirement that an ambulance (paramedic) arrive within 8:59 minutes 90% of the time.

In 1979 definitive care was a paramedic on an ambulance with a defibrillator and medications. Only physicians, nurses, and paramedics could use a defibrillator outside of a hospital. The ambulance was the only street-level provider of care above Red Cross Advanced First Aid.

Doctor Eisenberg reflected on the evolution of prehospital care when he gave the C. J. Shanaberger Lecture in 2006. He observed that a study from King County, Washington, demonstrated no improvement in survival rates over a 25-year span. Eisenberg’s response was to establish the Resuscitation Academy to go beyond a speeding ambulance to develop and deliver a community-based 10 step program that improves cardiac arrest survival.

4:00 minutes from recognition to clinical intervention

What would happen if we focused on community response to get a chest compressor and AED to a patient’s side within 4 minutes of a cardiac arrest alarm? What would that system look like?

Many of the advanced skills that were restricted to highly qualified medical caregivers in 1979 are available to a large part of the caregiver and general public population.

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Myers J.B, C. M. Slovis, et al. (2008) Evidence-Based Performance Measures for Emergency Medical Services Systems: A Model for Expanded EMS Benchmarking. A Statement Developed by the 2007 Consortium U.S. Metropolitan Municipalities’ EMS Medical Directors. Prehospital Emergency Care 12(2) 141-151

Eisenberg, M.S.; L. Bergner and A. Hallstrom. (1979) Cardiac Resuscitation in the Community: Importance of Rapid Provision and Implications for Program Planning. JAMA (241(18) 1905-1907

Eisenberg, M.S. The C. J. Shanaberger Lecture: The Evolution of Prehospital Cardiac Care: 1966-2006 and Beyond. Prehospital Emergency Care October-December 2006 10(4) 411-417.

Featured image, two women provide CPR in street.