Mass Casualty Incident Management: Part 1

Just as MCIs come in a variety of forms, so do the size and design of emergency response systems to deal with them.


Mass casualty incidents can shake even the most seasoned first responder. Weather emergencies can arrive fast and furious like a tornado, or slow and low like a flood. Mass gathering sports events will give you time to plan ahead, while a multi-car crash on the highway will not. Mass casualty incidents may require a fire department response for hazardous materials, or a law enforcement response for an active crime scene.

But just as you can categorize the types of MCIs, so too can you categorize the most common types of EMTs and paramedics who respond to them. No doubt you’ve met all four types:

The first is the Negative Nelly who thinks, “What’s the point in all of this preparation? It’ll never happen here.”

Next is the Chief Chaser who thinks, “The chiefs (or supervisors) take all those MCI classes. They’ll figure it out before I get there.”

Then there’s the Rogue Responder who thinks, “In chaos like this, you can forget your training. All the rules go out the window. Just dive in and grab as many patients as you can.”

Finally there’s You, the first responder who is calm and confident that, although the guidelines for managing an MCI are different from the ones which we use in our daily EMS practice, the MCI rules themselves are very simple, practical and practicable. You know that when it comes to multi casualty incident management, there are five key jobs which must be addressed, each with its own simple tasks to streamline incident management and improve patient care and outcome.

Because of the wide-ranging nature of MCIs, this series is designed to give you broad and basic tools that can be easily recalled, even at 3 a.m. on the side of the road on a dark and stormy night. As always, consult and follow your local protocols. If your service subscribes to more specific or modified versions of these guidelines then by all means learn, use and practice them regularly so that they can be recalled and implemented anytime, anywhere and under any circumstances.

Before we can talk about what to do at an MCI, we have to define exactly what an MCI is. Just as MCIs come in a variety of forms, so do the size and design of emergency response systems to deal with them. Because of this, different regions may use different definitions for MCIs. Even so, at their core they all come down to this: An incident becomes a mass casualty when patient care needs (number and severity of patients) outstrip immediately available resources.

As an example, picture two ambulances in the same response district, each capable of carrying up to two ALS patients, both responding to the same motor vehicle accident where four patients are reported to be injured. Just because one ambulance arrives first and can only carry two patients does not mean that they’ll need to declare a four-person MCI when they get there. Both ambulances are considered “immediate resources” because, in this example, they’re both close enough that they’ll be able to operate together on scene to care for the four patients.

But what if the first ambulance arrives on scene to find four patients and, before the other ambulance arrives, discovers that a third vehicle carrying five people was involved. This has the potential for another five patients, making for a total of nine patients for the resources in this response area.

At this point, the first ambulance crew could choose from a number of different paths. They could avoid going into MCI mode by getting on the radio and calling for more resources (ambulances), then scoop two patients who look the worst and head for the hospital. Or, they could hope for (or maybe even encourage) refusals of care, therefore decreasing their patient needs. Or, with no muss and no fuss, without screaming on the radio or mummifying every bystander in banner tape, the first ambulance crew could change the rules of the game by going into MCI mode. By initiating (Job 1) a simple, small-scale MCI they can triage (Job 2) (identify the most severe patients), move them to a safe area to begin to treat (Job 3) them, and transport (Job 4) these patients via arranged / staged (Job 5) ambulances to the nearest appropriate hospitals, thus maximizing patient care and outcome and minimizing chaos, panic, radio traffic and impact on area ambulance services and hospital resources.

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