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Predicting Casualty Severity and Hospital Capacity

Predicting Triage Severity

The majority of terrorist attacks against Americans involve conventional weapons (for example, bombs, rockets, and missiles). Terrorist bombings have caused, and can be expected to cause, the following pattern of casualties:

  • 1/3 of acute casualties are critical (dead on scene, die at hospital, require emergency surgery, or require hospitalization)
  • 2/3 of acute casualties are treated and released from the emergency department.
Table. Severity Predictor for Mass Casualty Events*
Triage Category
All Casualty Victims -->1/3 Critical Casualties -->Black

Red I, II

Yellow III
2/3 Non-Critical Casualties -->Yellow III

Green IV

* The following factors can change the pattern of casualties:

  • Use of manufactured weapons (i.e., military ordinance),
  • Explosion in a confined space or,
  • Collapse of buildings or other structures

If one of these factors is present, the pattern of casualties can change and the number of critical casualties may double.

Predicting Hospital Capacity to Care for Critical Casualties

The number of available operating rooms (ORs) is a major factor in determining a hospital’s capacity to care for critically injured casualties.

Capacity to Care for Critical Casualties ~ Number of Available Operating Rooms

When the number of predicted or actual casualties exceeds the number of ORs that are available, consider transferring or diverting critical casualties to other hospitals.

Predicting Hospital Capacity to Care for Non-Critical Casualties

The capacity of the radiology department is a major factor in determining a hospital’s capacity to provide timely care for non-critical casualties. It is recommended that each casualty exposed to a blast have a chest X-ray to screen for fractures, foreign bodies, blast lung, or other injuries. Each X-ray should take around 10 minutes of X-ray machine time. Therefore, the radiology department should be able to see approximately 6 patients per hour for each available machine.

Capacity to Care for Non-Critical Casualties / hour ~ (# of X-ray Machines*) X (6 patients/hour)

* available fixed and portable X-ray machines

When actual or predicted number of non-critical casualties exceeds the radiology capabilities of the hospital, consider transferring or diverting non-critical casualties to other nearby hospitals with capacity.

Emergency Medical Treatment and Active Labor Act (EMTALA)

The Department of Health and Human services Secretary's Advisory Committee on Regulatory Reform has recommended changes in EMTALA that will improve community mass casualty management. The changes include

  1. “use of community based EMS protocols (e.g., established 911 protocols) is not a violation of EMTALA,”
  2. “in the event of bioterrorism, or the threat of bioterrorism, EMTALA does not apply to those hospitals directly affected,” and
  3. “where hospitals follow a community based, regional or CDC directed protocol (especially for highly contagious outbreaks like small pox) EMTALA does not apply.”

More information about the EMTALA is available from the Centers for Medicare and Medicaid Services website.

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