Mass-casualty incident

Anniston, AL, January 21, 2011: Healthcare workers triage simulated victims during an MCI drill at the Center for Domestic Preparedness.

A mass casualty incident (often shortened to MCI and sometimes called a multiple-casualty incident or multiple-casualty situation) is any incident in which emergency medical services resources, such as personnel and equipment, are overwhelmed by the number and severity of casualties. For example, an incident where a two-person crew is responding to a motor vehicle collision with three severely injured people could be considered a mass casualty incident. The general public more commonly recognizes events such as building collapses, train and bus collisions, earthquakes and other large-scale emergencies as mass casualty incidents. Events such as the Oklahoma City bombing in 1995 and the September 11 attacks in 2001 are well-publicized examples of mass casualty incidents.

Declaration of an MCI

A mass casualty incident will usually be declared by the first arriving unit at the scene of the incident. However, it may alternately be declared by a dispatcher, based on the information available from people who call their local emergency telephone number about the incident. A formal declaration of an MCI is usually made by an officer or chief of the agency in charge. Initially, the senior paramedic at the scene will be in charge of the incident, but as additional resources arrive, a senior officer or chief will take command, usually using an incident command system structure to form a unified command to run all aspects of the incident. In the United States, the Incident Command System is known as the National Incident Management System (NIMS). According to the Federal Emergency Management Agency, "NIMS provides the template for the management of incidents."

Agencies and responders

A mass casualty incident can involve a variety of responders and agencies. The most common are listed below.

Emergency medical services

• Certified first responders or emergency medical responders may arrive as part of local emergency medical services, or may arrive on their own. They will assist with all aspects of patient care, including triage and treatment at the scene, and transport from the scene to the hospital.
• Paramedic and emergency medical technician (EMT) personnel may arrive in ambulances, in their personal vehicles, or from another agency. They will have control of all aspects of patient care, as assigned by the medical officer or incident commander.
• Ground ambulances will be assigned to the transport sector to transport patients and personnel to and from the incident scene, emergency departments of hospitals, and a designated helipad. These ambulances may be municipal services, volunteer services, or from private corporations.
• Air ambulances will transport patients from the scene or from designated helipads to receiving hospitals.

Fire and rescue

• Firefighters will perform all initial rescue-related operations, as well as fire suppression and prevention. They may also provide medical care if they are trained and assigned to do so. They may arrive on a fire truck, in their personal vehicles, or from another agency. Many areas near airports will have automatic mutual aid agreements with airport fire departments in the event of a plane crash outside of the airport boundaries.

Public safety

• Police officers will secure and control access to the scene, to ensure safety and smooth operations.
• Utility Services will ensure that utilities in the area are turned off as necessary, in order to prevent further injury or damage at the scene.

Specialized teams

HazMat specialists in Level II/B protection suits carry a patient out of the incident zone to be decontaminated.

• Specialized rescue teams may be part of the local fire department; they may be associated with the state, provincial, or federal governments; or they may be privately operated teams. These teams are specialists in specific types of rescue, such as Urban search and rescue (USAR) or Confined Space Rescue.
• HazMat teams are responsible for cleaning up and neutralizing any hazardous materials at the scene. Sometimes these will be specialized CBRNE (chemical, biological, radiological, nuclear and high-yield explosives) teams.
• National Guard Units have medics specifically trained in mass-casualty triage who may be called in to respond to a disaster-related incident.

Public services

• Railways and transportation agencies will be notified if an incident involves their tracks or right-of-way, or if they are required to cease operations in and through affected areas. Transportation agencies will provide buses to transport lightly injured people to the hospital. Buses can also provide shelter at the scene (for example, "warming buses") if required.
• The media play an important role in keeping the general public informed about the incident and in keeping them away from the incident area. However, a Public Information Officer should be assigned as the only designated responder who communicates with the media, to prevent the spread of misinformation.
• Non-governmental organizations such as St. John Ambulance, the Order of Malta, the Red Cross, the Red Crescent, the Medical Reserve Corps, and the Salvation Army will provide assistance with all aspects of a mass casualty incident, including trained medical staff, vehicles, individual registration and tracking, temporary shelter, food service, and many other important services.

Hospitals

• Hospitals with emergency departments will have a mass casualty incident protocol which they initiate as soon as they are notified of an MCI in their community. They will have preparations in place to receive a massive number of casualties, like calling in more staff, pulling extra and spare equipment out of storage, and clearing non-acute patients out of the hospital. Some hospitals will send doctors to the scene of the incident to assist with triage, treatment, and transport of injured persons to the hospital.

This is not an exhaustive list, and many other agencies and groups of people could be involved in a mass casualty incident.

Flow of an MCI

Ideally, once an MCI has been declared, a well-coordinated flow of events will occur, using three separate phases: triage, treatment, and transportation.

Triage

Main article: Triage

In an MCI drill aboard Naval Air Station Oceana, Firefighter/EMT Greg Tetro breaks the rear glass of an automobile to rescue a trapped victim.

The first-arriving crew will conduct triage. Pre-hospital emergency triage generally consists of a check for immediate life-threatening concerns, usually lasting no more than one minute per patient. In North America, the START system (Simple Triage and Rapid Treatment) is the most common and is considered the easiest to use. Using START, the medical responder assigns each patient to one of four color-coded triage levels, based on their breathing, circulation, and mental status. The triage levels are:

•   Immediate: Patients who have major life-threatening injuries, but are salvageable given the resources available
•   Delayed: Patients who have non-life-threatening injuries, but are unable to walk or exhibit an altered mental status
•   "Walking Wounded": Patients who are able to ambulate out of the incident area to a treatment area
•   Deceased or Expectant: Used for victims who are dead, or whose injuries make survival unlikely.

Triage personnel do not conduct treatment, with the exception of:

• Airway maneuvers;
• Tourniquets for life-threatening hemorrhage; and
• Where allowed by local protocols, needle decompressions for tension pneumothoraces

Generally, a small group of responders, usually the first two or three crews on scene, can complete triage.

When responding to a chemical or biological incident, the first-arriving crew must establish safety zones prior to entering the scene. Safety zones include:

• The hot zone: The contaminated area
• The warm zone: The area where HazMat specialists will decontaminate patients and fellow responders
• The cold zone: The safe zone, where any personnel who are not specially trained in HazMat and do not have chemical or biological protection gear must remain at all times. The cold zone should be roughly 200–300 yards from the incident, uphill and upwind. It should also be at least 50 yards uphill and upwind from the warm zone.

These zones should be clearly identified and with engineer tapes, lights, or cones. All responders and patients must leave the hot zone in designated pathways into the warm zone where they will be decontaminated. A designated officer should be posted at the hot zone and warm zone to make sure all contaminated personal are treated and decontaminated before entering the cold zone.

Treatment

Once casualties have been triaged, they can be moved to appropriate treatment areas. Unless a patient is Green Tagged and ambulatory, litter bearers will have to transport patients from the incident scene to safer treatment areas located nearby. These treatment areas must always be within walking distance, and will be staffed by appropriate numbers of properly certified medical personnel and support people. The litter bearers do not have to be advanced medical personnel; their role is to simply place casualties onto carrying devices and transport them to the appropriate treatment area. Casualties should be transported in order of treatment priority: Red-Tagged patients first, followed by Yellow-Tagged, then Green-Tagged, and finally Black-Tagged.

Each colored triage category will have its own treatment area. Treatment areas are often defined by coloured tarpaulins, flagging tape, signs, or tents. Upon arrival in the treatment area, the casualties are re-assessed and they are treated with the goal of stabilizing them until they can be transported to hospitals; transported to the morgue or medical examiner's office; or released.

On-site morgue

Some mass-casualty incidents require an on-site morgue, for several reasons:

• To await transfer of these victims to a permanent morgue;
• When the deceased must be removed to access injured victims;
• To keep the deceased out of public sight and prevent heightening distress, fear, or panic in an already emotionally-charged scene

Most often, on-site morgues are set up on the far side of the incident, is in an enclosed area such as a temporary tent or nearby building.

Transport

Ambulance on scene with emergency lights on

The final stage in the pre-hospital management of a mass-casualty incident is the transport of casualties to hospitals for more definitive care. If an insufficient number of ambulances is available, other vehicles may transport patients, such as police cars, firetrucks, air ambulances, transit buses, or personal vehicles. As with treatment, transport priority is decided based on the severity of the patient's injuries. Usually, the most seriously injured are transported first, with the least serious transported only after all the critical patients have been transported.

However, in an effort to remove as many lightly injured civilians as possible, an incident commander may choose to have those least seriously injured transported to local hospitals or interim-care centres in order to provide more room for emergency personnel to work. It is also possible that lightly injured casualties will be transported first when access to those who are more severely injured will be delayed due to heavy or difficult rescue efforts.

Definitive care

The care that is rendered at the scene of an MCI is usually only temporary and is designed to stabilize the casualties until they can receive more definitive care at a hospital or an interim-care centre.

Interim-care centre

An interim-care centre is a temporary treatment centre which allows for the assessment and treatment of patients until they can either be discharged or transported to a hospital. These are often placed in gymnasiums, schools, arenas, community centres, hotels, and or other locations that can support a field hospital setup. Permanent buildings are preferred to tents as they provide shelter, power, and running water, but many governments maintain complete field hospital setups that can be deployed anywhere within their jurisdiction within 12–24 hours. While full field hospitals require a significant amount of time to deploy (in relation to the length of most incidents), emergency personnel can set up temporary interim-care centres fairly quickly if needed using the personnel and resources they have on-hand. These centres are usually staffed by a combination of doctors, nurses, paramedics/emergency medical technicians, first responders, and social workers (for example, from the Red Cross), who work to get families reunited after a disaster.

Mass casualty event

Generally, in the healthcare field, the term "mass casualty event" (MCE) is used when hospital resources are overwhelmed by the number or severity of casualties. During these incidents, hospitals can discharge all fit patients, dedicate more resources to the emergency department, and expand their intensive care unit to accommodate anticipated long-term care needs. While up to 80% of victims will be transported from the scene to hospitals, others who are less injured might walk themselves to these facilities and increase the load at the closest facility to the incident.

MCEs can include bioterrorism attacks, chemical emergencies, radiation emergencies, and natural disasters like weather.

See also

• START triage
• Incident Command System (ICS)
• National Incident Management System (NIMS)
• ETHANE (mnemonic for the information to include when declaring an MCI)
• Pentagon MASCAL (an MCI drill in 2000)