The Challenge of Triage for CBRNE and Mass Casualty Incidents

By Deborah W Cohen, Biodefense Graduate Certificate Program

Imagine you have travelled across the country to attend a professional conference. While attending a presentation, the session is suddenly interrupted by news that other attendees are falling ill from a chlorine leak at the conference center’s pool. There are sounds of sirens and chaos outside. The presenter asks everyone to stay calm. They resume their presentation, but about an hour later a handful of individuals in the room begin to fall ill. As you being to wonder if this is connected to the incident outside at the pool, you suddenly become incapacitated and fall off your chair. The last thing you see is first responders wearing hazmat gear entering the room. 

This was the initial stage of the scenario for the Tabletop Capstone Exercise on the last day of the U.S. Army’s Hospital Management (HM) – Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Incidents training course held in late January 2021. I was assigned to the RED HOSPITAL response team which was comprised of military and civilian members. As the scenario unfolded, we organized a response utilizing the doctrine, tools, and planning concepts of the Hospital Incident Management System (HIMS) taught during the first four days of the course. 

Many kinds of emergency incidents happen in our communities. The scenario to which we responded could have been caused by a “conventional” emergency or a terrorist attack involving a chemical agent and a biological agent. The nature of the attack would be determined through an investigation using evidence collected during and after the response. The disaster response, however, must start immediately and be premised on the National Incident Management System (NIMS) guided by the National Response Framework (NRF). The NRF is the national emergency management doctrine formulated by the Office of the Assistant Secretary of Preparedness and Response (ASPR) in the Department of Health and Human Services. The NIMS provides federal support to state and local incident managers and is designed to be scalable, flexible, and adaptable to all types of incidents. 

This emergency management system was put in place by Homeland Security Presidential Directive 5 in 2003 which sought to “enhance the ability of the United States to manage domestic incidents by establishing a single, comprehensive national incident management system.” The guiding principles of the NIMS are the template for local Incident Command Systems (ICS). By way of background on nomenclature, Incident Management Systems (IMS) are more comprehensive in scope than Incident Command Systems (ICS).  IMS also deal with the longer term direct and indirect effects of an event in a community. ICS can be thought of as aa component of IMS dealing more narrowly with specific urgent actions of getting an incident under control.  However, ICS and IMS are designed to be compatible with each other. The ICS operates on the principle of “unity of effort” which provides the multiple organizations responding to an incident a way to coordinate and focus their efforts efficiently by setting aside overlaps and competition across authorities and jurisdictions.Local hospitals are required to prepare for and respond to disasters using the Hospital Incident Command System (HICS) in compliance with NIMS. One of the ways that HICS improves emergency planning, response and recovery is by clearly designating who is responsible for different roles across the response command organization such as incident command, security, medical technology, personnel, finance, supply, logistics, public information, liaison services, and transport.  Since compliance with NIMS is a condition for any healthcare facility to receive Federal assistance, the adoption of ICS by first responders and HICS by healthcare organizations enables government and non-government entities to respond cooperatively to an incident.

The week of training provided by the HM-CBRNE course covered the properties of each of the CBRNE threats and their respective hospital management protocols. These threat-response relationships were further illustrated by incident scenarios. In these scenarios, triage was, for me, the main component that best characterized the realities of emergencies.  In contrast to the Medical Management of Chemical and Biological Casualties (MCBC) Course that I attended last year, which focused on battlefield triage, this course also included lessons on triage in a  civilian community setting.

We learned about three types of triage systems that hospitals use for trauma casualties that are not specifically designed for CBRNE incidents: (1) field triage conducted at the scene of an incident to match available resources with patients; (2) inter-hospital sorting for the transfer of more seriously injured patients to higher level care facilities; and (3) mass-casualty sorting and prioritizing during a disaster. There is also a reverse triage system to sort hospital patients for discharge. These triage systems support the creation and utilization of surge capacity by hospitals to deal with mass casualty incidents, which resonates today with the challenges posed by the COVID-19 pandemic.  Triage of casualties caused by a CBRNE incident can be complicated by the unique effects of these weapons as well as by pre-existing conditions among patients and the impact of psychological trauma. 

The U.S. Army uses three types of “sorting” systems for triage: medical treatment, decontamination, and evacuation. For medical treatment, there are four categories of triage: Immediate, Delayed, Minimal, and Expectant (IDME). In medical triage, Immediate cases require intervention within a few minutes using the ABCDDs: Airway, Breathing, Circulation, Decontamination, and Drugs. In CBRNE events, immediate intervention can also use the (MARs)2 system:  Mask, attention to issues of Massive hemorrhage, Airway, Antidotes,Respirations, and Rapid removal of contaminants. Delayed cases can tolerate a short postponement of medical attention. Minimal patients are those with minor, stable, or resolving injuries that can tolerate a longer delay in treatment.  Expectant patients will not survive without the use of scarce resources that could otherwise be used for possible survivors.  For a civilian community setting, triage of CBRNE casualties will be handled differently.  Four different triage systems for CBRNE casualties, each with their own advantages and limitations, have been developed: (1) Rapid Assessment of Mentation and Pulse (RAMP); (2) Sort Assess Life-saving Treatments Treatment and/or Transport (SALT); (3) Simple Triage and Rapid Treatment (SMART); and (4) Simple Triage and Rapid Treatment (START).

A second triage system developed by the military is for decontamination and it depends on the type of agent and exposure involved. It is typically conducted concurrent with medical triage. For decontamination, the sorting categories are Immediate, Operational, and Thorough. The Assistant Secretary for Preparedness and Response (ASPR) and its partners have developed a protocol for decontamination triage based on a tool called the Primary Response Incident Scene Management (PRISM).

The third triage system is for evacuation which includes Urgent, Priority, and Routine (UPR) sorting categories.  Triage for evacuation is based on the determinations of medical triage and time factors. Patients who can be matched with available treatment and are most likely to survive and recover will be evacuated. Patients in the Urgent category are those who need treatment within two hours. Priority triage is for those who need treatment within four hours. Routine triage patients can wait for up to 24 hours for treatment. The Routine group of evacuees will also include terminal patients.

Col. (ret.) James M. Madsen, MD, the Army presenter, explained that while all triage methods are based on on-the-scene determinations of urgency, survivability, and resource availability, mass-casualty and CBRNE triage is different from other kinds of triage in several ways. For triage of victims of a CBRNE incident, the speed of operation is even more critical, personal protective equipment (PPE) is always needed due to the risk of contamination, verbal communication is difficult, hands-on exams may not be possible, and first responders are sorting simultaneously for medical treatment, decontamination, and evacuation. CBRNE triage schemes are very challenging as they must quickly account for the clinical implications of the specific CBRNE agent to which the victims have been exposed. For instance, the length of the latent period before symptoms manifest, the risk of secondary contamination, and the existence of specific antidotes varies among different chemical warfare agents. The most important message about triage for mass casualties and CBRNE incidents is that while there are many methods under development, there is no consensus about the best option to employ in every case. It was sobering to learn that current triage methods are not adequate for the complex situations, conditions, and circumstances that characterize the evolving landscape of CBRNE and terrorism events.

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