Disaster Preparedness

Classic Terminology

The words internal and external refer to a hospital setting to help distinguish whether an event has occurred within the hospital grounds (internal) or in the community (external). This concept distinguishes between preparing for casualties to arrive at the hospital and managing casualties or resources within the hospital. This geographic distinction between internal and external may be useful, but it has severe limitations. Many events can be both internal and external to the facility at the same time (e.g., major earthquake or hurricane). Furthermore, simply identifying the location of the event does not answer the critical question: How are response capabilities affected? The key consideration is what actions are required to mitigate and then to rectify the situation.

Some definitions have been based on the number of casualties. As previously described, the absolute number of patients is much less important than whether their medical and health needs exceed the resources to care for them at a given point in time. The attack on the World Trade Center in 2001 ( Fig. e14.2 ) illustrates this point. Although over 2000 victims died in the collapse of the twin towers, the actual impact on the overall health system of New York City was relatively mild. The capacity of the system to care for citizens living in New York remained intact. In contrast, Hurricane Katrina in 2005 resulted in a similar number of deaths, but caused such massive destruction, including the loss of medical and health infrastructure, that federal disaster medical assistance teams (DMATs) were deployed to Louisiana to provide medical personnel and supplies.

Routine Multiple-Casualty Triage

To assist in the understanding of triage techniques, it is useful to consider a routine out-of-hospital event with multiple casualties (e.g., a multivehicle collision). In such situations, rescue personnel often use a simple triage and rapid treatment (START) technique that depends on a quick assessment of respiration, perfusion, and mental status. These three assessments can be remembered by the mnemonic RPM ( r espirations, p erfusion, and m ental status). To initiate this sorting process, all victims who are able to walk are asked to move away from the incident area. These patients are classified as green, or “walking wounded,” and are reassessed after the more immediately critical patients are triaged.

The Pediatric Triage Tape (PTT) and JumpSTART have been proposed for the triage of children. JumpSTART is a modification of the START triage protocol that includes an additional step of five rescue ventilations for children presenting apneic and modification of criteria for hypoventilation and tachypnea, as well as for a decrease in mental status ( Fig. e14.3 ). The PTT uses criteria that change in proportion to increasing victim size. The parameters for a child 50 to 80 cm in length are illustrated in Figure e14.4 . In an evaluation of five triage tools using a large trauma database, JumpSTART performed best for children under 8 years of age with CareFlight triage performing best overall. Although START, JumpSTART, the PTT, and CareFlight appear to be useful tools, only START has been evaluated in an actual disaster situation. As such, no pediatric triage system has proven clear superiority over any other, and therefore, recommendations on choice of pediatric triage system should be left to individual jurisdictions. Proper education and team training may be more important than triage system choice.

As illustrated in Figure e14.5 , a rescuer using START triage can assess each patient in seconds, quickly checking respiratory rate, pulse, and ability to follow commands (mental status), and divide the patients into the remaining three categories: red (immediate), yellow (delayed), and black (deceased). The only patient care interventions provided during this process are the opening of an obstructed airway and direct pressure on obvious external hemorrhage. At this point, patients are generally transported to a hospital for definitive care. Most often, patients arrive with a color-coded triage tag and are reassessed and re-triaged by the hospital staff ( Fig. e14.6 ). An outcomes-based evaluation of the performance of START triage in an actual disaster (2002 Placentia Linda train crash) demonstrated acceptable levels of undertriage (100% sensitivity of the red category and 90% specificity of the green category). However, significant amounts of overtriage occurred. Use of START also appropriately prioritized the transport of victims, with patients triaged as red arriving at hospitals earlier than patients triaged as yellow or green.

Given the significant number and variability of proposed disaster triage systems, a multidisciplinary group in the United States attempted to standardize these platforms by developing the Model Uniform Core Criteria in 2011. These core criteria promulgated a set of principles to guide creation of mass casualty triage algorithms. Based on these guidelines, this group also proposed a potential national triage system for the United States. The result, derived by consensus, was referred to as SALT ( s ort, a ssess, l ifesaving interventions, and t reatment or transport). It differs from START mainly in the assessment of respirations (i.e., relies on a qualitative evaluation of respiratory distress rather than a number), the requirement for performance of certain lifesaving interventions (chest decompression), and an unstructured estimate of survivability. The algorithm is more complicated than START, and no current data exist evaluating its sensitivity, specificity, or other performance characteristics after use in an actual incident. As such, it is not currently possible to make recommendations for the use of SALT triage. For anyone considering implementing an adult mass casualty triage algorithm, we recommend using START triage until more evidence emerges describing the performance of SALT triage in actual disasters.

Catastrophic Casualty Management

Triage during a disaster differs from triage performed in routine out-of-hospital and hospital settings. The number of victims is vastly increased, while medical resources are severely limited or initially absent. Patients may remain on scene for an extended period and may require periodic reassessment, which will be challenging. If hospitals remain accessible, patients tend to seek care at the closest one, a phenomenon known as convergence. Hospitals close to the disaster scene are overwhelmed, whereas hospitals located only a few miles away may receive few if any patients. The triage process will then be decentralized, occurring at multiple sites, or compartments, simultaneously throughout the disaster zone. Rather than a single scene or localized disaster, this can be thought of as a compartmentalized disaster.

To address this situation, researchers developed the Secondary Assessment of Victim Endpoint (SAVE) system of triage. The SAVE triage system is designed to identify patients who are most likely to benefit from care available under austere field conditions or in a resource-poor environment. When combined with the START protocol, SAVE triage is useful for any scenario in which multiple patients experience a prolonged delay in accessing definitive care.

The SAVE methodology is designed for use by health care providers under two conditions: (1) for those working within the disaster zone that begin caring for patients immediately but may not be able to transport patients to a definitive care facility for days, and (2) for those caring for patients within hospitals where demand for resources exceeds supply. This second situation can occur as hospitals attempt to increase surge capacity. It is immediate and dynamic rather than delayed and static.

The SAVE triage methodology divides patients into three categories: (1) those who will most likely die despite available care, (2) those who will survive without care, and (3) those who will benefit from austere field interventions. Only those patients expected to improve receive care beyond basic or comfort measures. The decision to place patients in a particular group is based on field outcome expectations derived from existing survival and morbidity statistics. An example is a situation in which three victims require chest tubes (two victims require one tube each and one victim requires two tubes), but only two chest tubes are available. The SAVE principles guide providers to place their last two chest tubes into the two victims who need one rather than into the single victim requiring two tubes.

Since nuclear, biologic, and chemical terrorism has become a threat, triage systems have been modified to address these situations. These systems attempt to incorporate the added threats from exposure and contamination into the triage process. One such method for biologic casualties triages many individuals to home observation rather than hospitalization to optimize resource use and to minimize the spread of the infectious agent. This strategy has been used effectively during the COVID-19 outbreak. In addition, responders require protection from secondary contamination or exposure; therefore, part of the triage algorithm should include a risk assessment and determination of whether and what type of personal protective equipment should be donned before patients are assessed. This was illustrated during the 2014 to 2016 Ebola outbreak when health care providers initiated Ebola exposure screening procedures during initial patient contact before engaging in patient evaluation and treatment. A similar approach was also utilized initially in the COVID pandemic. Once community spread developed, however, this practice was replaced by the assumption that all patients were infected. In a combined event scenario, such as an incident involving a radiologic dispersion device, rapid patient assessment is critical to prevent patient deaths from traumatic injuries while awaiting medical care from responders concerned about their own health and safety.

Also associated with disaster incidents are large numbers of psychological casualties. These individuals have not received physical injuries or toxic exposures but experience significant psychological trauma and are at risk for posttraumatic stress disorder and other psychiatric illnesses. The emergency plan should include a mechanism to provide psychological triage, such as PsySTART, that can rapidly assess individuals to identify those at risk for serious and prolonged illness and assure that they have access to mental health care. Responders effectively used PsySTART immediately after Hurricane Sandy and Typhoon Haiyan.

While performing triage, the emergency clinician should consider the effects of extreme age, underlying disease, and multiple injuries when assessing the potential prognosis for a given patient. Treatment of many nontraumatic emergencies can be accomplished with field interventions that do not consume extensive resources. Patients with such illnesses should usually be triaged to the treatment area.

Vulnerable Triage Populations

Certain groups of patients, such as children, the elderly, the disabled, and homeless persons, may have special needs that present challenges to routine triage. For example, if a person is too young to follow commands or is deaf, the individual would not be able to respond to a command to walk away from an incident site for reasons that may not indicate severe injury. Triage schemes should attempt to accommodate language and cultural barriers, as well as physical and psychological limitations that result in social or medical vulnerabilities.

Special Triage Categories

To maximize human resources, disaster victims who would normally be triaged to the observation area can be triaged to the treatment area if they possess special skills valuable to the medical team (e.g., medical expertise and translation skills). By increasing the number of functional team members, the effectiveness of the overall response will improve. The guiding principle supports the disaster triage goal of maximizing benefit to the most people.

Emergency Medical Services System Protocols

To prepare adequately, hospitals should be familiar with and involved in the development of county or regional plans. For example, some EMS systems use automatic systems such that each hospital may be expected to accept a fixed number of critically ill or injured and minor patients without advanced notification.