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Maryland's EMS system has effectively managed mass casualty incidents involving 10 to 40 people

It is estimated that 25,000 of the 150,000 trauma deaths each year are preventable, and that trauma systems are effective in reducing preventable deaths by as much as 80 percent. The Maryland emergency medical services (EMS) system is considered by many to be a national pioneer and leader in emergency care. As with many States, Maryland's preparation for mass casualty incidents (MCIs) has been integrated into its overall EMS systems planning. This approach has been very effective in managing these traumatic events, according to a study of EMS responses to eight such incidents involving from 10 to nearly 40 injuries each (a total of 203 injuries) over a 3-year period.

The study was supported in part by the Agency for Healthcare Research and Quality (HS09326) as part of the Trauma Resource Allocation Model for Ambulances and Hospitals (TRAMAH) program. It showed that a total of 78 percent of injuries required ambulance transportation. Less than 2 percent of the injured patients were taken to hospitals outside of Maryland, with an average of three hospitals involved per incident. These traumatic incidents included the unintentional discharge of a canister of tear gas inside a school bus, which poisoned 19 children; a car crashing into a restaurant; a train derailment; a mass gunshot incident; a bus crash injuring 38 people; a rowhouse fire; the collision of two commuter trains; and a head-on crash of a passenger car into a school bus carrying 33 children.

None of these incidents required more than a level 1 response; that is, they could be handled by local EMS and rescue resources within the State of Maryland. Seven of the MCIs occurred within an area of the State where the number of day-to-day severe injuries was most concentrated (Baltimore-Annapolis-Washington triangle) and where the EMS system was most intensified in terms of hospital and ambulance resources.

Extremely high-casualty disasters or multiple simultaneous MCIs occur so rarely that they could hold a State EMS system "financially hostage" in trying to fully plan for them, according to Charles C. Branas, Ph.D., of the University of Pennsylvania School of Medicine. The researchers suggest that an annual record of smaller MCIs that have a high probability of recurrence can provide a more realistic basis of planning for EMS systems. Their analysis of these eight cases was based on use of administrative and public record data from May 1993 to May 1996.

See "A case series analysis of mass casualty incidents," by Dr. Branas, Ronald F. Sing, D.O., and Andrew D. Perron, M.D., in the October 2000 Prehospital Emergency Care 4(4), pp. 299-304.

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