Disasters, Mass Casualty Incidents
Ronald N. Roth
Amir Blumenfeld
Susan M. Briggs
I. Introduction
The time, location, or complexity of the next disaster cannot be predicted. Disasters, natural, or human-made, encompass a wide spectrum of threats. Incidents involving weapons of mass destruction (WMD) create a “contaminated” environment and additional challenges to the medical response system. Disasters differ in the degree to which the medical and public health infrastructure of the affected community is disrupted and to which outside assistance is needed. The location of the incident, the availability of local resources, and the number, severity and diversity of injuries are major factors in determining whether a mass casualty incident (MCI) requires resources from outside the affected community. While the spectrum of disasters is endless, all disasters have similar medical and public health concerns.
Definitions
A disaster occurs when the local resources are unable to meet the needs of the event. The required resources may include additional manpower, heavy rescue equipment, or expertise in dealing with an infectious disease outbreak or WMD release.
MCIs are events that cause casualties large enough to overwhelm the medical and public health services of the affected community.
Scope. MCIs have traditionally implied a limited geographic location. Many disasters are complex and involve large geographical regions. The earthquake, subsequent tsunami, and nuclear disaster in Japan (2011) is an example of a complex natural disaster involving a large geographic region.
Location influences the impact and the ability of medical personnel to respond to an incident.
In an austere environment, resources, transport, access, security, and other aspects of the physical, social, or economic environments impose severe constraints on the adequacy of immediate care for the population.
Incidents in an urban location have a high potential for a large number of injuries, loss of local resources, and destruction of infrastructure.
MCIs as a result of the accidental escape of toxic materials (e.g., methyl-iso-cyanate in Bhopal, India, 1984) or the purposeful release of harmful materials in a WMD incident (Sarin attack on the Tokyo subway, 1995) have the greatest potential to produce chaos and mass casualties.
II. Key Principles
Disaster medical care is not the same as conventional medical care. While the objective of conventional medical care is to do the greatest good for the individual patient, a key principle of disaster medical care is to do the greatest good for the greatest number of patients. Disaster medical care requires a fundamental change in the approach to the care of patients (crisis management care/altered standards of care) to achieve this objective.
A consistent approach to disasters is the accepted practice throughout the world. This strategy is called MCI response. MCI response has the primary objective of reducing the morbidity (injury/disease) and the mortality (death) associated with the disaster.
The basic medical and public health concerns are similar in all disasters, differing by the responses required and need for outside assistance, regional, national, or international.
Basic medical concerns related to MCI responses include:
Search and rescue
Triage and initial stabilization
Evacuation
Definitive care
Basic public health concerns related to MCIs include:
Water
Food
Shelter
Sanitation
Safety/security
Transportation
Communication
Disease surveillance
Endemic/epidemic diseases
III. Incident Command System (ICS)
The overall success and safety of a disaster response will largely depend on the quality of the ICS. A well-developed ICS is the most effective method to manage disasters both in the prehospital and hospital environment. Almost all incidents will involve responders from multiple organizations with differing command structures. The ICS is a standardized all-hazards management approach designed to enhance the ability of multiagency organizations (fire, police, emergency medical services, hospitals) and/or multiple jurisdictions to work together effectively in response to a disaster. The ICS uses a common organizational structure and language to achieve this goal and is the accepted standard for all disaster responses. The ICS creates a hierarchy of roles and responsibilities to direct the management of personnel and resources.
ICS comprises five major functional areas. The general responsibilities of each member of the ICS team are predetermined and independent of the nature of the incident. Not all activities are used for every disaster. Functional requirements, not titles, determine ICS hierarchy.
ICS hierarchy
Incident command. Maintains overall responsibility for disaster response and sets objectives and priorities for the disaster response. Several key personnel report to the incident commander (IC). The Liaison Officer assists the IC in communicating with and coordinating the various organizations responding to the disasters. The Public Information Officer provides appropriate information to the public and press. The safety officer is responsible for worker safety.
Operations. Conducts operations, directs disaster resources.
Planning. Develops action plans, maintains status of resources.
Logistics. Provides resources, personnel, and supplies.
Financial/administrative. Monitors costs.
ICS key concepts
Unity of command. Individual responder reports to only one supervisor.
Span and control. An individual should ONLY supervise between three and seven other responders.
Objective related tasks. Specific objectives are ranked and assigned as specific tasks.
Several principles are important for effective use of the ICS in disasters:
The IC and other key positions are identified and trained before a disaster occurs, not chosen at the time of a disaster.
ICS must be started early, before an incident gets out of control.
Medical and public health responders who usually work independently must adhere to the structure of the ICS to avoid negative consequences.
The structure of the ICS is the same regardless of the nature of the disaster. The only difference is in the particular expertise of key personnel and the extent of the ICS utilized in a particular disaster. For example, the safety officer will vary by the type of disaster (i.e., an infection control expert might serve as the safety officer during a biologic incident).
IV. Medical Response to Disasters
The National Disaster System (NDMS) is a federally coordinated system that augments the Nation’s medical response capability. The overall purpose of the NDMS is to assist State and local authorities in providing disaster relief. Four categories of response teams are part of the NDMS.
Disaster Medical Assistance Teams (DMAT)
International Medical Surgical Response Teams (IMSURT)
Disaster Mortuary Operational Response Teams (DMORT)
National Veterinary Response Teams (NVRT)
Disaster Medical Assistance Teams (DMATs) are groups of professional medical personnel (supported by a cadre of logistical and administrative staff) designed to be a rapid-response element to supplement local medical care. There are over 50 DMATs in the United States. IMSURT are teams of medical specialists who provide surgical and critical care during a disaster. Each of the three IMSURT teams is equipped with a rapidly deployable, fully equipped field hospital, including operating rooms (ORs).
Search and rescue. Many local response organizations have developed search and rescue teams as integral part of their disaster plans. In large scale incidents, specialized teams from outside agencies may be called upon for assistance. In the United States, a National Urban Search and Rescue System coordinates federal and civilian search and rescue responses.
Triage and initial stabilization. Triage is the most important and often the most psychologically challenging mission of disaster medical response. The objective of disaster triage (field triage) is to do the greatest good for the greatest number of people. The goal of disaster triage is to identify the critical patients with the greatest chance of survival and the least expenditure of time and resources (equipment, supplies, and personnel). Both under-triage and over-triage of victims limits the effectiveness of the disaster response. Under-triage is the assignment of critically injured casualties requiring immediate care to a “delayed” category. Over-triage is the assignment of non-critical survivors with no life-threatening injuries to the “urgent” category. Over-triage is more common in MCIs.
Field triage. Victims are categorized on site into two categories, acute and nonacute. Simplified color coding may be done if resources permit. Personnel are typically first responders from the local population or local emergency medical personnel.
Medical triage. Rapid categorization of victims at a casualty collection site or fixed or mobile hospital is performed by experienced medical personnel with knowledge of the medical nature and consequences of various injuries (e.g., burns; blast or crush injuries; or exposure to chemical, biologic, or radioactive agents). Color coding may be used.
Red. Casualties which require immediate lifesaving interventions.
Yellow. Casualties for whom treatment can be delayed. Note that victims of bomb blasts can suffer occult internal injuries. These can be easily missed on initial assessments and patient may be under-triaged. Some facilities in Israel have abandoned the yellow category for victims of a bombing incident.
Green. Individuals who require minimal or no medical care.
Black. Deceased or expected to die. This triage category includes victims not expected to survive due to the severity of injuries and/or lack of resources. Some triage schemes place expectant victims under yellow or in a separate category.
Evacuation triage. Priorities for transfer to medical facilities are assigned to disaster victims. The casualty collection site should have easy visibility for
disaster victims and convenient exit routes for air and land evacuation. Victims are matched with available receiving facilities. Often victims with minor injuries can be sent to more distant facilities, keeping closer facilities available for higher priority victims.
Definitive medical care. Definitive medical care improves, rather than simply stabilize, a casualty’s condition. In some disasters, local hospitals may be destroyed, transportation to medical facilities may not be feasible, or the environment may be contaminated. In these situations, definitive care must be provided outside traditional medical facilities.
Hospital teams with mobile equipment that can provide a graded, flexible response to the need for definitive medical care in disasters are keys to a successful disaster response and have been developed by many countries and hospitals.
Disaster medical assistance teams must be able to provide care for routine emergencies/diseases as well as disaster-related injuries.
Evacuation. Evacuation is useful in a disaster to decompress the disaster area and provide specialized care for specific casualties, such as those with burns and crush injuries.
Modes of evacuation from the disaster site to the local hospital and from local facilities to tertiary care centers may include ground transport, helicopter transport, and transport by fixed-wing aircraft.
Medical providers must take into account patient stresses of flight that may be encountered during evacuation and affect medical care. These include changes related to the hypobaric environment, decreased partial pressure of oxygen, turbulence, vibration, varying temperatures, and low humidity.
V. Public Health Response to Disasters
Medical providers must understand the impact of disasters on the public health infrastructure to have an efficient medical response.
The Rapid Needs Assessment (RNA) provides timely evaluation of the impact of the disaster on the affected population. The RNA includes:
Assessment of the magnitude of the disaster;
Assessment of basic services (water, food, sanitation, and emergency temporary shelter);
Assessment of the capacity of the affected community to respond to the disaster needs.
Media reports can provide valuable information regarding the magnitude of the disaster, particularly in the area of greatest impact. Media has the ability to direct specific resources (helicopters, reporters, cameramen) to investigate a disaster site. Monitoring media reports and working with the media is important.
VI. Hospital Preparedness for Disasters and Multi-Casualty Incidents
Preparation. Mass casualty situations pose challenges for any medical system or hospital. No system will function efficiently without proper preparedness programs. The disaster plan should be applicable to all-hazards and should cover all aspects relevant to such events and provide detailed modes of operation for MCI management including:
Pre-designed protocols and standing orders. Each hospital should have written protocols and standing orders pertaining to the various scenarios anticipated during an MCI. Protocols contain series of actions that need to be taken once MCI is declared. Standing orders are translation of these activities into practical orders detailing the sequential actions that need to be executed by different staff members. (e.g., Protocol-–All designated relevant personnel should be notified; Standing order-–Emergency Department (ED) administrator: Notify hospital director, blood bank, radiology, etc.) Area or person-specific protocols should be clear, concise, and easily accessible.
Pre-arranged equipment stocks, and stockpiles. All necessary equipment items including stretchers, medications, medical devices, protection gear, etc. should
be prepared in advance. These items should be stored in an accessible location and prepared to be mobilized in time of need.Related posts:
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