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Altered Standards of Care in Mass Casualty Events

Public Health Emergency Preparedness

This resource was part of AHRQ's Public Health Emergency Preparedness (PHEP) program, which was discontinued on June 30, 2011, in a realignment of Federal efforts.

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Chapter 2. Health and Medical Care Delivery in a Mass Casualty Event

Health and Medical Care Standards

Substantial work has already been done and continues to be undertaken throughout the country to improve the ability of health systems to respond to acts of terrorism or other public health emergencies. Much of the planning in this area focuses on increasing the surge capacity of affected delivery systems through the rapid mobilization and deployment of additional resources from the community, State, regional, or national levels to the affected area. However, few of these plans specifically address a situation in which the delivery system is unable to respond (even if only temporarily) according to established standards of care due to the scope and magnitude of a mass casualty event.

A key issue upon which the experts agreed is that the goal of the health and medical response to a mass casualty event is to save as many lives as possible. There is consensus that, to achieve this goal, health and medical care will have to be delivered in a manner that differs from the standards of care that apply under normal circumstances. This issue is not addressed in a comprehensive manner in many preparedness plans.1

Finally, the experts also agreed that for health and medical care delivered under these altered standards to be as effective as possible in saving lives, it is critically important that current preparedness planning be expanded to explicitly address this issue and to provide guidance, education, and training concerning these altered care standards.

Standards of health and medical care, broadly defined, address not only what care is given, but to whom, when, by whom, and under what circumstances or in what places. A comprehensive set of standards for health and medical care specifies the following:

What—what types of interventions, clinical protocols, standing orders, and other specifications should be used in providing health and medical care?

To whom—which individuals should receive health and medical care according to their condition or likelihood of response?

When—with what urgency should health and medical care be provided?

By whom—which individuals are certified and/or licensed to provide care within a defined scope of practice and other regulations?

Where—what facility and system standards (pre-hospital, hospital, alternate care site, etc.) should be in place for the provision of health and medical care?

Under normal conditions, current standards of care might be interpreted as calling for the allocation of all appropriate health and medical resources to improve the health status and/or save the life of each individual patient. However, should a mass casualty event occur, the demand for care provided in accordance with current standards would exceed system resources. In a small rural hospital, 10 victims from a local manufacturing accident might be considered a mass casualty event. In a metropolitan area, several hundred victims would be manageable within system resources. In an event involving thousands of victims, preserving a functioning health care system will require a move to altered standards of care. It may also be necessary to create both pre-hospital operations and alternate care sites to supplement hospital care.

The term "altered standards" has not been defined, but generally is assumed to mean a shift to providing care and allocating scarce equipment, supplies, and personnel in a way that saves the largest number of lives in contrast to the traditional focus on saving individuals. For example, it could mean applying principles of field triage2 to determine who gets what kind of care. It could mean changing infection control standards to permit group isolation rather than single person isolation units. It could mean limiting the use of ventilators to surgical situations. It could mean creating alternate care sites from facilities never designed to provide medical care, such as schools, churches, or hotels. It could also mean changing who provides various kinds of care or changing privacy and confidentially protections temporarily.

1 In preparation for the expert meeting, information and a sample of existing triage protocols and preparedness models were collected and reviewed. A brief summary of that review is provided in Appendix B.

2 The term triage refers to the process of sorting victims according to their need for treatment and the resources available.

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Hypothetical Scenarios Illustrating Changes in Delivery of Care

Two hypothetical mass casualty scenarios were developed by the panel of experts to help illustrate specific ways in which care standards would have to change in response to a mass casualty event (Exhibit 1). The first scenario involves the simultaneous explosion of multiple dirty bombs in a metropolitan area. The second scenario involves the release of a biological agent. The use of these two scenarios facilitates the examination of the impacts and implications of two serious events that differ in nature and occur at different velocities. For example, the explosive scenario would produce a large number of casualties upon detonation and place an immediate demand on all aspects of the health care system. The biological scenario would develop more slowly, with its peak impact occurring at the end of an unknown incubation period.

The examination of these scenarios revealed that the explosive and biological terrorism mass casualty scenarios are likely to share common elements, but also raise issues that are specific to the nature of each event and the speed with which the event places demands on the health care system. The following discussion highlights these common elements. Event-specific issues for each scenario appear in Exhibits 2 and 3 and are organized by setting (scene [or pre-hospital], hospital, and alternate care sites).

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Changes in Care Delivery Common to Two Scenarios

At their peaks, both the explosive and biological mass casualty scenarios are likely to involve the following:

Exhibit 1. Two Mass Casualty Scenarios Used to Identify Anticipated Changes to Care Delivery

Two mass casualty scenarios were developed by the panel of experts to help identify how care delivered at the event scene or pre-hospital setting, hospital, and alternate care sites would vary from care provided under normal circumstances.

Scenario 1. Multiple, simultaneous explosions

A series of multiple dirty bombs have been set off simultaneously throughout a large metropolitan subway system. The city's hospitals also have been targeted and approximately 40 percent of the hospitals are no longer operational. There are an estimated 10,000 victims.

Scenario 2. Biological agent release

A highly lethal communicable biological agent with a set but initially unknown incubation period has been released in a heavily populated area. Diagnosis is dependent on laboratory tests. Medical staffs are required to use personal protection equipment. Treatment requirements include patient isolation and the use of ventilators; however, the impact and effectiveness of treatment is unknown.

  • Triage efforts that will need to focus on maximizing the number of lives saved. Instead of treating the sickest or the most injured first, triage would focus on identifying and reserving immediate treatment for individuals who have a critical need for treatment and are likely to survive. The goal would be to allocate resources in order to maximize the number of lives saved. Complicating conditions, such as underlying chronic disease, may have an impact on an individual's ability to survive.
  • Triage decisions that will affect the allocation of all available resources across the spectrum of care from the scene to hospitals to alternate care sites. For example, emergency department access may be reserved for immediate-need patients; ambulatory patients may be diverted to alternate care sites (including nonmedical space, such as cafeterias within hospitals, or other nonmedical facilities) where "lower level" hospital ward care or quarantine can be provided. Intensive or critical care units may become surgical suites and regular medical care wards may become isolation or other specialized response units.
  • Needs of current patients, such as those recovering from surgery or in critical or intensive care units; the resources they use will become part of overall resource allocation. Elective procedures may have to be cancelled, and current inpatients may have to be discharged early or transferred to another setting. In addition, certain lifesaving efforts may have to be discontinued.
  • Usual scope of practice standards that will not apply. Nurses may function as physicians, and physicians may function outside their specialties. Credentialing of providers may be granted on an emergency or temporary basis.
  • Equipment and supplies that will be rationed and used in ways consistent with achieving the ultimate goal of saving the most lives (e.g., disposable supplies may be reused).
  • Not enough trained staff. Staff will be scared to leave home and/or may find it difficult to travel to work. Burnout from stress and long hours will occur, and replacement staff will be needed. Some scarce and valuable equipment, such as ventilators, may not be used without staff available who are trained to operate them.
  • Delays in hospital care due to backlogs of patients. Patients will be waiting for scarce resources, such as operating rooms, radiological suites, and laboratories.
  • Providers that may need to make treatment decisions based on clinical judgment. For example, if laboratory resources for testing or radiology resources for x-rays are exhausted, treatment based on physical exam, history, and clinical judgment will occur.
  • The psychological impact of the event on providers. Short- and long-term stress management measures (e.g., Critical Incident Stress Management programs) are essential for providers and their families.
  • Current documentation standards that will be impossible to maintain. Providers may not have time to obtain informed consent or have access to the usual support systems to fully document the care provided, especially if the health care setting is damaged by the event.
  • Backlog in processing fatalities. It may not be possible to accommodate cultural sensitivities and attitudes toward death and handling bodies. Numbers of fatalities may make it difficult to find and notify next of kin quickly. Burial and cremation services may be overwhelmed. Standards for completeness and timeliness of death certificates may need to be lifted temporarily.

Exhibit 2. Changes Specific to Care Delivery in a Multiple Explosion (Scenario 1)

Scenario 1: A series of multiple dirty bombs have been set off simultaneously throughout a large metropolitan subway system. The city's hospitals also have been targeted and approximately 40 percent of the hospitals are no longer operational. There are an estimated 10,000 victims.

In addition to the changes common to both scenarios described in this report, the following additional changes in medical care delivery may occur under this scenario.


  • Physicians most likely will not be at the scene. Emergency medical services and other first responders will perform triage.
  • Anyone at the scene who can help may need to act as "medical staff."
  • Triage protocols currently used (e.g., START, JumpSTART) may not apply, given magnitude of the event.
  • Buses and other forms of nonmedical transportation may have to be used to supplement emergency transport systems.
  • With an insufficient number of usual pre-hospital treatments and supplies, such as spineboards and immobilization equipment or the need to respond quickly, ambulatory victims may have to walk or self-transport to the nearest facility or hospital.


  • Even if a hospital is among those still functioning, it may experience water, heating and cooling, electricity shortages, and communication problems.
  • Reserved medical supplies and equipment may not arrive quickly enough from national and regional resources, such as the Strategic National Stockpile, given the velocity of the event.
  • The provider-patient relationship may be interrupted. Providers may have service-specific assignments rather than patient group assignments (e.g., they would perform all intravenous infusions rather than provide all aspects of care for a group of patients).
  • The hospital may need to exercise strict control of access to and from the hospital and diversion of ambulatory victims to alternate care sites. The emergency department should be protected in order to care for more critically injured victims (i.e., those who cannot walk to the hospital) who will arrive later.
  • Decontamination practices will change, so that only gross decontamination (e.g., removal of clothes) is performed.
  • Only lifesaving surgeries will be performed, and initial surgical care will aim to stabilize the patient. When more resources become available, additional surgery to fully treat injuries can occur.
  • The practice of ordering only the supplies needed for immediate use means that limited supplies will run out quickly. This situation will be compounded by same vendor/resource dependence. It will also be compounded by an event requiring large amounts of specialized supplies or care. Examples include mass casualty events involving mostly children (substantial pediatric supplies needed) or demand for burn beds and related care.

Alternate Care Sites

  • Ambulatory patients will be redirected to alternate care sites within or outside of the hospital, such as the hospital cafeteria or a nearby school, to be re-triaged and receive care for minor injuries.

Exhibit 3. Changes Specific to Care Delivery in a Biological Event (Scenario 2)

Scenario 2: A highly lethal communicable biological agent with a set but initially unknown incubation period has been released in a heavily populated area. Diagnosis is dependent on laboratory tests. Medical staff are required to use personal protection equipment. Treatment requirements include patient isolation and the use of ventilators; however, the impact and effectiveness of treatment is unknown.

In addition to the changes common to both scenarios described in this report, the following additional changes in medical care delivery may occur under this scenario.


  • There will be no initial "scene" in a biological event. Pre-hospital activity related to triage, diagnosis, and case identification, will be done at physicians' offices, community health centers, emergency departments, and even pharmacies.
  • Communication among providers will be important in order to develop a coordinated understanding of the symptoms and a systematic approach to treatment that is consistent with coordinated planning.
  • Public health/epidemiological surveillance, including data mining from disparate sources (such as over-the-counter medication purchases, work/school absenteeism, etc.) may be useful in outbreak analysis and epidemiological projection.
  • Emergency medical services may be used to transport victims to specific quarantine or isolation locations and other alternate care sites.


  • The emphasis will be on prevention and contagion control, as well as treatment, depending on staff and resources available. Victims who are conclusively diagnosed as infected will be isolated. Group isolation may be necessary.
  • "Suspected" exposure patients will be quarantined. If laboratory tests and other diagnostic tools are not available, these patients may be treated based on histories reported and physician clinical judgment.
  • Staff shortages are likely at all hospitals due to concerns about exposure to the infection. A recent survey suggests that as many as 50 percent of hospital workers may not show up for work during a bioterrorism event.
  • Protection of all staff and their families, such as prophylaxis, will be needed to help ensure adequate staffing (including nonmedical staff such as housekeeping and dietary staff).
  • "Early treaters/responders" will have to be quarantined and treated as if they have been exposed to the biological agent. Their quarantine will have a negative impact on provider supply.
  • Demand for pharmaceuticals is likely to outstrip the supply. Both experimental and expired drugs may have to be used.
  • Initially, standards of care initially may improve for the first wave of patients, but as the number of victims increases, standards could degrade.

Alternate Care Sites

  • Alternate care sites will be used for triage and distribution of vaccines or other prophylactic measures, as well as for quarantine, minimum care, and hospice care.

Based on a review of the health and medical care issues presented by these two scenarios, the panel of experts identified a need for more guidelines to ensure a systematic approach to decisionmaking in mass casualty events. Guidelines should take into account and be scaleable to the size, nature, and speed of the event, so that they can guide the following decisions:

  • How to ensure and protect an adequate supply of trained providers and support staff.
  • How to triage patients into groups by the nature of their condition, probability of success of interventions/treatment, and consideration of resources available.
  • How to maintain infection control and a safe care environment.
  • How to use and reuse common supplies and equipment, such as gloves, gowns, and masks.
  • How to allocate scarce clinical resources of a general nature, such as beds, surgery
  • capability, and laboratory and other diagnostic services.
  • How to allocate scarce and highly specialized clinical resources, such as decontamination units, isolation units, ventilators, burn beds, and intensive and critical care units.
  • How to treat specific conditions, including how to make best use of available pharmaceuticals.
  • How to protect health care providers and support staff and their families.
  • How to modify documentation standards to ensure enough information to support care and obtain reimbursement without posing an undue administrative burden.
  • How to manage excessive fatalities.

As illustrated in these scenarios, the occurrence of a mass casualty event will require significant changes in the way in which health and medical care is delivered under extraordinary circumstances. The panel of experts was quite clear in its view that if the health care system is to be successful in saving as many lives as possible, planning, education, and training efforts should be focused on the development and implementation of appropriate altered standards of care in response to a mass casualty event. A framework and set of principles to guide work in this area were developed by the panel and are presented in the next chapter.

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