Mass Casualty Incidents

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On the anniversary of 9/11, it only seems appropriate to discuss what you would do if confronted with more victims of traumatic injury than you can handle. This can happen anywhere, anytime, and in normal times or times of trouble.

For the survival medic caring for their family or a group off the grid, most patient encounters will be unhurried, routine, and one-on-one. If you have trained and accumulated supplies, your encounter with any one patient should be, with any luck, well within the limits of your expertise and resources. In the New Normal, however, the medic might be confronted with multiple victims of trauma simultaneously and have to make quick decisions. We refer to this type of event as a mass casualty incident (MCI).

A mass casualty incident is any event in which your medical resources are inadequate for the number and severity of injuries incurred. MCIs can be quite variable in their presentation and can occur in both good times and bad. They might be:

  • Terrorist bombings, such as occurred on 9/11.
  • Active shooter events.
  • The aftermath of a storm, such as a tornado or hurricane.
  • Consequences of civil unrest.
  • Mass transit mishaps (train derailment, plane crash).
  • A car accident with, say, three people significantly injured (and only two ambulances available).
  • Doomsday scenario events, such as nuclear weapon detonations.

You may read that the COVID-19 pandemic is considered an MCI. From an organizational standpoint, it is. As medical resources were overwhelmed in some areas, a similar command structure and set of community safeguards was implemented to “flatten the curve” and stay within the available limits of personnel and equipment.

Most often, however, we are talking about incidents where there are multiple traumatic injuries. The response to injuries caused by a tornado or active shooter is different than the response to a pandemic. Often difficult to predict, the damage is done in a matter of a few minutes. A multiple vehicle or mass transit accident occurs in a second. When these events happen, all the emergency resources of the city or town go into high alert and activate.

Pandemics come with their own unique problems: In a car accident or tornado, the rescue personnel arrive after the event and rarely become victims themselves. With infectious disease outbreaks, however, the medical assets start getting sick, leaving less resources for patient care. Facilities receive patients over a prolonged period of time, much like a field hospital in a war zone.

The effective medical management of the above events requires rapid and accurate triage. Triage comes from the French word “trier” (to sort). It’s the process by which medical personnel rapidly assess and prioritize injured individuals. When the first evaluations occur at the scene, it’s called “primary triage.”

In trauma MCIs, triage identifies those with injuries most likely to benefit from immediate, priority attention. In pandemics, triage identifies those who may require rapid isolation from the general patient population. In both cases, you attempt to do the most good for the most people. Note that we didn’t say: “the best possible care for each individual.”

Let’s concentrate on trauma MCIs: Let’s say you’re in a marketplace somewhere in the Middle East or perhaps your survival group has had hostile encounters with another group that are increasing in frequency. You hear an explosion and come upon a horrific scene. There are twenty of your people on the ground, some moaning in pain. There were probably more, but only twenty are in one piece. You are the first responder.

The 5 “S’s” Of MCI Triage

As the first to arrive at the scene, you must assume to role of  “Incident Commander” until someone with more medical expertise arrives. What do you do? Your initial actions comprise what we call the “5 S’s” of evaluating a mass casualty scene:

1)Safety Assessment: Many terrorists employ an insidious strategy using primary and secondary bombs. The main bomb causes the most casualties, and the second bomb is triggered as rescue personnel (you) arrive.

You might grimace when we advise not approaching the injured in a hostile setting. Yet, your primary goal as medic is your own self-preservation. Keeping the medical personnel alive is likely to save more lives down the road. You do your family and community a disservice by becoming the next casualty.

Here’s a tragic example: In the immediate aftermath of the 1995 Oklahoma City bombing, various medical personnel rushed in to aid the victims. One of them was a heroic 37-year-old Licensed Practical Nurse named Rebecca Anderson who, as she entered the area, was struck by a falling piece of concrete. She sustained a head injury and died five days later. So, whether it’s falling bricks or bullets flying, be as certain as possible that there is no ongoing threat.

2)Size up the Scene: Ask yourself the following questions: What’s the situation? Is this a mass transit crash? Did a building on fire collapse? Was there a shooting or explosion?

How many injuries are there? How severe are they? How many victims? Are there any uninjured that could assist you? Are the victims all together or spread out over a wide area? Are there lanes open that are large enough for vehicles to come through and help transport victims?

3)Send for Help: If you sized up the scene correctly, you have a lot of important information to pass on to emergency medical services or, in survival scenarios, other group members arriving at the scene.

If modern medical care is available, notify emergency services and say (for example): “I am calling to report an accident involving three cars at the intersection of Hollywood and Vine. There are at least seven people injured that will require medical attention. People are trapped in their cars and one vehicle is on fire.”

In three sentences, you have informed the authorities that a mass casualty event has occurred, what type of event it was, where it occurred, an approximate number of patients that need help, and the types of care or equipment that may be required. In survival settings, use your walkie-talkie or other communication device to notify base camp of the situation. Let them know what you’ll need in terms of personnel and supplies. If you are not medically trained, contact the person who is the group medic. The most experienced medical person who arrives becomes the new Incident Commander.

4)Set-Up: Determine likely areas for various triage levels (see below) to be further evaluated and treated. Also, determine the appropriate entry and exit points for victims that need immediate transport to medical facilities, if they exist. If you are blessed with lots of help at the scene, assign triage, treatment, and transport team duties.

5) S.T.A.R.T.: Triage uses the acronym S.T.A.R.T., which stands for Simple Triage And Rapid Treatment. The first round of triage, known as “primary triage,” should be fast (30 seconds per patient if possible) and does not involve extensive treatment of injuries. It should be focused on identifying the triage level of each patient.


Evaluation in primary triage consists mostly of quick evaluation of respirations (or the lack thereof), perfusion (adequacy of circulation), and mental status. Other than controlling massive bleeding and clearing airways, very little treatment is performed in primary triage.

Although there is no international standard, triage levels are usually determined by color:

  • Immediate (Red tag): The victim needs immediate medical care and will not survive if not treated quickly (for example, a major hemorrhagic wound/internal bleeding). This person has top priority for treatment.
  • Delayed (Yellow tag): The victim needs medical care within two to four hours. Injuries may become life-threatening if ignored, but can wait until red tags are treated. An example of a yellow tag would be an open fracture without major bleeding.
  • Minimal (Green tag): Generally stable and ambulatory (“walking wounded”) but may need some medical care (for example, broken fingers or a sprained ankle).
  • Expectant (Black tag): The victim is either deceased or is not expected to live (for example, open fracture of skull with brain damage, multiple penetrating chest wounds).

The medic off the grid probably won’t have colored tags or tape. Instead, use felt markers (handy items to have in your pocket). If you only have a black marker, you can still write numbers on the victims’ foreheads. If you use numbers:

  • 1 is immediate/red (top priority)
  • 2 is delayed/yellow
  • 3 is minimal/green
  • 4 is dead/expectant/black

The number method is the standard in many countries. it’s also useful if you’re color blind.

Knowledge of this system allows a rescuer to understand the urgency of a patient’s condition. You should know that, without modern medical care, a lot of red tags and even some yellow tags will become black tags. It will be difficult to save someone bleeding internally without surgical intervention.

Let’s go through an example of a mass casualty incident and discuss how you would perform primary triage.

Here’s our hypothetical scenario: It is market day at your village near the border with another (hostile) group. You hear an explosion. You are the first one to arrive at the scene, and you are alone. There are about twenty people down, and there is blood everywhere. What do you do?

Referring back to the 5 S’s, let’s say that you have already determined the SAFETY of the current situation and SIZED UP the scene. It appears that a bomb has exploded. There are no hostiles nearby, as far as you can tell. You don’t see anything that you suspect might be a second device. Therefore, you believe that you aren’t currently in danger. The injuries are significant (there are body parts) and the victims are all in an area no larger than, say, 20 yards.

The incident occurred on a main thoroughfare your people use, so there are ways in and out. You have SENT FOR HELP on your handheld radio and described the scene. Several survival group members have replied, including a former ICU nurse. The area is relatively open, so you can SET UP different areas for various triage categories. Now you can START (Simple Triage And Rapid Treatment).

Call out as loudly as possible: “I’m here to help, everyone who can get up and walk and needs medical attention, get up and move to the sound of my voice. If you are uninjured and can help, follow me.”

You’re lucky, 13 of the 20 victims still in one piece sit up, or at least try to. 10 can stand, and you direct the walking wounded to an area you designated. These people have cuts, burns, and scrapes. A couple are limping; one has obviously broken an arm. Two bruised but sturdy individuals volunteer to join you. By this simple communication, you have made your job as temporary Incident Commander easier by identifying the walking wounded (Green Tags) and getting some immediate help. You still have 10 victims down.

Your team then goes to the closest victim on the ground and proceeds in an organized manner to the next nearest victim in turn. In this way, you will triage faster and more effectively than trying to figure out who needs help the most from a distance.

Let’s cheat just a little and say that you happen to have SMART tags in your pack. SMART tags are handy tickets which allow you to mark a particular triage level on a patient. Once you identify a victim’s triage level, you remove a portion of the end of the tag until you reach the appropriate color and place it around the patient’s wrist.

It is important to remember that you’re triaging, not treating. The only treatments in START will be the control of heavy bleeding, opening airways, and elevating the legs in case of shock.


As you go from patient to patient, stay calm, identify who you are and that you’re here to help. Your goal is to find out who will need help most urgently (red tags). You will be assessing RPMs (Respirations, Perfusion, and Mental Status):

Respirations: Is your patient breathing? If not, restore the airway by tilting the head back and lifting the chin or, if you have them, insert an oral airway (Note: in MCI triage where time is of the essence, the rule against moving the neck of a victim due to risk of cervical spine injury is, for the time being, suspended). If you have an open airway but no breathing, that victim is tagged black. If the victim begins to breathe once an airway is restored or has a respiration rate of more than 30 times a minute (or less than ten), tag red. If the victim is breathing normally, move on to perfusion.

Perfusion/Pulse: Perfusion involves evaluating the adequacy of blood flow and circulation. Check for the presence of a (wrist or neck) pulse, then press on a nail bed or finger pad firmly and quickly remove. The coloration will go from pale back to normal color in less than two seconds if circulation is good. This is referred to as the Capillary Refill Time (CRT). If you’re not feeling a pulse or it takes longer than 2 seconds for nail bed color to return, tag red. If a pulse is present and CRT is normal, move to mental status.

Mental Status: Can the victim follow simple commands (“open your eyes,” “squeeze my hand”)? If the patient isn’t breathing excessively fast and has normal perfusion, but is unconscious or disoriented: Tag red. If they can understand you and follow commands, tag yellow if they can’t get up, or green if they can. Remember that, as a consequence of the explosion, some victims may not be able to hear you well.

It might be easier to remember all this by just thinking 30-2-Can Do:

  • 30 (less than 30 respirations)
  • 2 (CRT less than 2 seconds)
  • Can Do (follows commands)

It should be noted that different regions may use other systems of primary triage. This is, in our opinion, the simplest to use when no specialized equipment is available.

If there is any doubt as to the category, always tag the highest priority triage level. Not sure between yellow and red? Tag red. Once you have identified someone’s triage level, tag them and move immediately to the next patient unless you have major bleeding to stop. Any one RPM check that results in a red result tags the victim as red. Elevate the legs if you suspect shock.

When there are multiple victims, spend only as much time as is needed to determine the triage level. The only treatment you’ll provide in the primary triage phase will be to stop heavy bleeding and clear airways with a chin-lift jaw thrust. In this way, you’ll do the most good for the most people in the shortest amount of time, if not the best for every individual.

It stands to reason that you would be more effective if you had help. If uninjured or minimally injured victims can help you, say, apply pressure to a wound, you can move on to evaluate the next victim. A tourniquet or an airway in the medic’s pocket can be lifesavers.

Off the grid, the medic’s job is exponentially tougher, and some RED victims will assuredly end up tagged BLACK. You can only aim to achieve what Teddy Roosevelt once advised:

“Do what you can, with what you have, where you are.”

Joe Alton MD

That ol’ Dr. Bones

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