The daily operations of EMS systems focus on providing care and transport to individual patients with (usually) unlimited resources. This approach allows prehospital providers to attempt to maximize the chances of an individual's survival and reduce the morbidity they may experience from their injury or illness. In situations involving multiple/mass casualties incidents and disasters, the principles of “routine” field triage and transport decisions can change significantly, as the goals of patient care shift from doing the most good for a singular patient, to doing the most good for the most patients. Recognizing the regional variability inherent in prehospital emergency care, it is imperative for EMS physicians to understand the concepts in this chapter globally, but also to apply and understand them in the context of their local/regional EMS system(s). Specific aspects of daily operations are discussed elsewhere in the text.
Describe the theory behind the need for trauma triage in mass casualty incidents.
Describe the major field triage methods, and detail their use.
Describe the medical triage, transport, and treatment areas setup during an MCI.
Discuss the role of the EMS physician in assisting the triage officer(s) and transport officer(s) in their duties.
Discuss the pros and cons of the EMS physician limiting their role to aiding in the treatment area during an MCI.
Discuss field triage and retriage in prolonged events, or during times of limited hospital/transportation resources.
Triage, from the French trier meaning to sort, is a term initially ascribed to the process of sorting coffee beans. The transition from an agrarian process to a part of the medical evaluation process began with the efforts of Baron Dominique-Jean Larrey, Chief Surgeon of Napoleon's Army. Baron Larrey is credited with devising a system to identify and sort casualties of war on the battlefield and evacuate them via ambulances volantes to field hospitals.1 In this first use of medical triage, the goal was to identify soldiers with injuries that were survivable, with focus placed on providing the care needed to return the soldier to the battlefield as quickly as possible in order to maintain a sufficient fighting force. Following the Napoleonic wars, the battlefields of subsequent military engagements saw further refinement of the triage processes as the technology of health care and warfare developed. The development of antibiotics and advanced surgical techniques, recognition and treatment of shock, utilization of helicopters, and institution of “buddy care” to initiate immediately lifesaving interventions all had a significant role in the reduction of combat fatalities from a rate as high as 30% during World War II to a rate of less than 10% in the Afghan and Iraqi wars.1
As with much of our present-day trauma care practices, civilian triage methods were subsequently derived from wartime practices that have been adapted to peacetime needs stemming from natural, industrial, and criminal/terror-related disasters and multiple/mass casualty incidents. Now, the medical literature is plentiful with acronyms such as START, JumpSTART, SAVE, SALT, and TSS, and products such as triage kits containing color-coded tags, flags, tarps, vests, and other items are common in the consumer retail markets. For the end user, it can be challenging to determine which of several protocols and products are best chosen and implemented to maximize survival rates while maintaining a triage method that is cost-effective. One of these challenges is the lack of a universally accepted triage standard.
Several challenges exist behind the development and utilization of current triage methods, not the least of which is a paucity of evidence-based information on which to critically assess the accuracy and effectiveness of these schemes.
DEFINING THE NEED FOR TRIAGE
According to the World Health Organization, a disaster occurs when “normal conditions of existence are disrupted and the level of suffering exceeds the capacity of the hazard-affected community to respond to it.”2 The World Medical Association goes on to explain “from the medical standpoint, disaster situations are characterized by an acute and unforeseen imbalance between the capacity and resources of the medical profession and the needs of survivors who are injured or whose health is threatened, over a given period of time.”3
Disasters are usually on a very large scale and involve a large geographic area, with examples including the 2010 Haiti earthquake, Hurricanes Katrina and Rita in the US Gulf Coast in 2005, and the 2004 Indian Ocean Tsunami. More common are mass casualty incidents (MCIs), defined as “a situation that places a significant demand on medical resources and personnel but in which local response capabilities are not overwhelmed despite a large number of patients requiring triage and medical treatment.”4
In our daily prehospital and inhospital medical care, we expend significant resources with the goal of providing the greatest chance of survival for individual patients, that is, providing the “greatest good for the individual.” In the vast majority of events, scarcity of resources during disasters and MCIs necessitates a paradigm shift toward rationing and equitable utilization of resources so we may provide the “greatest good for the greatest number.”5 In very limited circumstances, an exception to this premise exists. The concept of reverse triage deserves special mention with regard to the overall concept of utilization of resources. Two applicable definitions of this term apply. In the civilian setting, reverse triage refers to focusing care resources on the most critically injured or “expectant” patients. In this form, reverse triage is specifically applicable to the allocation of resources for multiple victims of a lightning strike, where there is a high potential for survivability of patients in cardiac arrest if they receive prompt CPR and defibrillation. For further discussion of care of the lighting-strike victim, the reader is referred to Chapter 47. In the military or tactical setting, reverse triage refers to prioritization of resources to the least injured personnel in order to return them to duty as quickly as possible in order to maintain strength of defending forces or control of the tactical environment. After an appropriate fighting or defensive/protective force is preserved, care can be provided to more critically injured personnel who are deemed salvageable by applicable triage and treatment schemata based on the combat or tactical environment and available treatment and evacuation resources.
TRIAGE AS PART OF A COORDINATED RESPONSE SYSTEM
Triage exists as part of a larger, comprehensive and integrated response to an MCI or disaster. As such, it must be recognized that triage operations do not exist in a silo, as they are affected by and affect the actions of other responding entities. Bostick et al discuss a concept of systemic triage and define four orders of triage that occur in the recognition, response, and recovery stages of a disaster.6
In systemic triage, first-order triage is established in the general community that may be or has been affected by the incident. First-order triage is used by public health to help disseminate information that may help prevent injury, decrease exposure to a threat, and help resources from becoming overwhelmed by providing risk-specific information to the community about appropriate self-protection practices, indications for seeking medical care, and appropriate venues to seek shelter or care. Examples of steps taken in first-order triage may be shelter in place, community evacuation, or specific disease call centers such as the Canadian SARs Hotline. Second-order triage occurs in the prehospital setting and involves the identification, sorting, treatment, and evacuation of casualties to appropriate locations for definitive care. Third-order triage occurs at sites of secondary or definitive care and involves assessment of the medical needs of arriving patients, stabilization and transfer to definitive care, or provision of definitive care. Use of treatment protocols and redistribution of patients are actions taken in this order of triage. Finally, Fourth-order triage occurs at the regional level and involves monitoring of the disaster and appropriate resource allocation, including actions like activating the strategic national (pharmaceutical) stockpile or redistributing human, supply, and equipment resources within the affected area.6 Such a systemic approach allows for integration of the disaster response entities and maximizes the potential for increased casualty survival at each point of contact with victims and those at risk for disaster-related injury or illness. The coordination of response that is established by systemic triage is needed in order to provide victims of an MCI or disaster equal opportunity of survival, meaning all affected individuals are afforded equity in triage and the receipt of medical care that is consistent with their injuries and projected survivability, as well as prevailing resource constraints. This notion of equal opportunity in triage does not, however, guarantee either treatment or survival for all patients potentially affected by a catastrophic event.6
This chapter will focus second-order triage, the operations of triage in the identification of patients, their categorization, and prioritization for treatment and evacuation from an MCI/disaster scene. For more discussion regarding the role of EMS in disaster response, please see Section 12.
INJURY PATTERNS IN DISASTERS AND MCIs
With the exception of chemical, biologic, radiation, and nuclear (CBRN)-related events, an important concept to recognize about patients injured in disasters and MCIs is that their injuries tend to be similar to those that medical providers encounter in their regular daily trauma care.5 Thus, most prehospital providers already possess the skills needed to evaluate and care for these patients. Although fortunately, as Frykberg discusses, “the great majority of initial survivors are not critically injured,” the often large number of noncritical patients who must be assessed may make it more difficult to identify and provide immediate treatment to the 10% to 25% of patients who are critically injured.5 Additional challenge exists in determining which patients may or may not be salvageable, and one of the most difficult principles for triage providers to adapt to is that circumstances may require them to abandon casualties that would normally (in day-to-day operations) undergo heroic measures regardless of their chances of survival.
CBRN events may add an additional level of complexity to the assessment of disaster and MCI victims. This is especially true because most EMS providers do not usually encounter patients injured by CBRN mechanisms during their daily operations and thus have less experience and potentially less knowledge and understanding of disease and toxicology mechanisms on which to base their assessment and categorization of CBRN injured patients. The issues of EMS provider safety, when, which type, and how to use personal protective equipment, and when, where, and how to perform patient decontamination increase the complexity of triage decisions.
Victims of chemical exposure may experience immediate or delayed injuries in the absence of physical trauma. Patients may initially be well-appearing casualties that later deteriorate and experience life-threatening conditions such as cholinergic toxicity. Thus frequent retriage is a necessity. Providers also face challenges in the provision of immediately lifesaving treatment of chemically injured victims due to the availability, efficacy, and difficulty in administration of antidotes (ie, atropine and 2-PAM autoinjectors, the number of doses needed for effective treatment, etc). Furthermore, chemically exposed patients may pose an exposure risk to rescuers and require decontamination, which can slow the progress of moving patients from an incident scene to primary treatment and evacuation areas. Chemical-related events may occur in a discrete area or may be dispersed over a large geographic area depending on prevailing weather conditions and the nature of the chemical agent (a gas, vapor, or liquid).
Unlike chemical exposures, biologic exposures are unlikely to cause immediate injury and may have a latency period typically on the order of days. Although the initial exposure may have occurred at a discrete location, when patients begin to exhibit symptoms of their exposure they are unlikely to be confined to a discrete scene (ie, distributed over a larger geographic area). Therefore, the utilization of most primary triage methods is less likely to be effective during a biologic event.
The threat of a radiation exposure must be considered when developing a triage method that can be applied to “all hazards.” Although capable of inflicting a significant psychological impact on a large population, radiation dispersion devices (RDD) or dirty bombs are more likely to inflict life-threatening traumatic injury that is a direct result of the explosion/blast forces rather than immediately life-threatening injury from the radiation exposure itself. Unless a patient is contaminated with radioactive material, the radiation-exposed patient poses no radiation risk to the rescuer (ie, a patient who gets an x-ray is exposed to radiation, but is not a risk to other people). Although the number of physically injured victims may be small, the psychological impact of RDDs may result in a large number of “worried well.” While these patients are not likely to consume physical medical resources (medications, wound care supplies, etc) they do consume a significant number of personnel resources as they seek assessment and medical care. When considering the primary causes of injury in a dirty bomb event, it has been suggested that “no substantial revisions need to be made to MCI triage methods to account for radiation exposure.”7
In difference to an RDD event, victims from a nuclear event are likely to suffer life-threatening injuries resulting from blast, thermal, and ionizing radiation mechanisms. The type of radiation exposure (α and β particles, and γ-rays), intensity of exposure, degree of contamination, and duration of exposure are likely to be higher in a nuclear event compared to an RDD detonation. Because sources of ionizing radiation are dispersed in the environment, ongoing exposure can occur for both victims and rescuers who remain in the primary contamination zone. Patients close enough to the source of the nuclear incident to receive enough radiation exposure to result in acute radiation sickness are also likely to be within the primary lethal blast zone (blast area roughly double the area where “survival possible” exposure of 2 to 4.5 Gy.8
ASSESSMENT OF THE EFFICACY OF A TRIAGE METHOD
A common theme among many of the literature resources reviewed for the development of this chapter is discussion regarding the lack of sufficient data on which to base evaluation of the efficacy of existing triage methods. Of the few articles that have attempted to validate existing triage methods, because there is little existing data available regarding outcomes from real-life utilization of triage methods to actual MCIs and disasters, most studies are based on data surrogates such as retrospective application of protocol assessment criteria to patients in trauma registries. Considering that prospective assessment of a particular triage method is likely impossible due to barriers in predicting disasters, lead time in training providers, and certain ethical challenges, the use of these surrogates for data and efficacy assessment are necessary.
In addition to the lack of adequate data, many articles also cited the lack of a universally accepted gold standard or outcome measure with which to compare various triage methods. However, several different concepts have been identified as critical variables that must be considered when evaluating or developing a triage method.
Frykberg discusses the concept of the critical mortality rate, the percentage of deaths only among the critically injured, suggesting that “the outcome of critically injured casualties is the best indication of the success of medical care in an MCI.” By using this measure, triage methods would be compared based on their ability to identify and correctly categorize the critically injured patients, and would be judged on this specific survival score rather than on the overall disaster mortality rate (which would include the on-scene/immediate deaths as part of the entire fatality census).5
Several factors may influence the critical mortality rate achieved by a particular triage method. Ideally a triage method would correctly categorize each patient 100% of the time. However, certain rates of undertriage, inappropriate assignment of critically injured victims with life-threatening problems to a delayed category, and overtriage, assignment of noncritical casualties to immediate care, often occur. Undertriage places critical patients at risk of not receiving appropriate priority for treatment and transport. This may occur when victims have somewhat innocuous appearing injury patterns externally, but have significant internal injury (ie, small penetrating trauma from shrapnel). Conversely, casualties that have severe external injuries but have a low likelihood of survival may be overtriaged to the immediate category, rather than an “expectant” category. In either case, overtriage will lead to the consumption of resources that would best be utilized to care for the true “immediate” patients. Of the two, studies of MCI bombing events indicate that overtriage has been shown to have a greater negative impact, illustrating “a direct linear relationship between the rate of overtriage and the critical mortality rate of survivors”.9
Both over- and undertriage can be an effect of the triage method or of the rescuer who is using the method. Intrarater reliability occurs when an instrument results in identical triage categorization if the same evaluator rates the same patient twice within a short time period.10 Interrater reliability occurs when an instrument results in identical triage categorization of the same patient when evaluated by two different raters.10 In a well-developed triage method, rates of intra- and interrater reliability would be high.
When authors discuss the “testing” of a triage method, it is important to understand exactly what is being tested. Is one testing whether the scheme can predict patient outcomes, whether providers use the scheme accurately, or whether use of the scheme improves outcomes? In other words, when looking at the patient outcomes when a particular triage method has been utilized, it may be difficult to separate whether there was a success or failure of the tool itself, or success or failure in the ability of the providers to accurately/correctly use the tool.
The concept of construct validity, the ability of a test or process to assess what it is intended to assess, can be applied both to the validity of the triage method and in the tools used to assess the effectiveness of the method.11 The construct validity of several primary triage methods (START, SMART, CareFlight) has been assessed in a few studies, but no such assessment has been applied to secondary triage methods.10
In the initial chaos of an MCI or disaster, a certain amount of inaccuracy of triage must be expected and accepted. This inaccuracy can be mitigated, however, by utilizing secondary and tertiary triage at each point in the patient evacuation process (ie, arrival at a treatment zone, just prior to departure from a treatment zone, upon arrival at a destination hospital, etc). Such serial reassessments can help increase the accuracy of their diagnosis, can increase triage accuracy, and decrease the rates of under- and overtriage.
MAJOR FIELD TRIAGE METHODS AND THEIR USE
Several triage methods have been proposed, and they are utilized to various degrees across the United States and internationally. In 2008, a consortium of specialists was convened in the United States to develop and propose a national standard triage guideline. In their review of existing literature and products, they identified nine existing triage methods. Several commonalities were identified between these systems, although it was found that there is a lack of uniformity in aspects such as patient assessment principles and commonality of language (ie, Priority I, II, III; Immediate, Delayed, Minimal; Emergent, Urgent, Nonurgent, etc) that may result in confusion, especially if neighboring jurisdictions use differing triage methods. This panel focused their efforts on reviewing primary triage methods, including START, JumpSTART, Homebush, Triage Sieve, Pediatric Triage Tape, CareFlight, Sacco Triage Method, Military Triage, and CESIRA. Table 53-1 provides a summary comparison of these primary triage methods.
Comparison of Existing Triage Systems
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Comparison of Existing Triage Systems
|System ||Coding ||Status Assigned Based on ||Interventions Allowed Before Categorizing as “Dead” ||Comments |
|Simple Triage and Rapid Transport Treatment (START) || |
Walking wounded: green
Immediate: Resp. rate >30, slow capillary refill, or cannot follow commands
Walking wounded: able to walk
Deceased: not breathing after one attempt to open airway
Delayed: all others
|Open airway || |
|JumpSTART || |
Immediate: respiratory rate <15 or >45 or irregular, or no palpable peripheral pulse, or inappropriate posturing or unresponsive (P or U on AVPU scale)
Delayed: unable to walk, respiratory rate 15-45; and palpable peripheral pulse, and A or V on AVPU
|Open airway, if not breathing and palpable radial pulse give five rescue breaths || |
Developed for children ages 1-8
Parallel to structure of START
Children carried to an ambulatory area should be assessed first
Modification for nonambulatory children
|Homebush || || |
Immediate: not walking, breathing, but not able to follow commands, or no radial pulse, or resp. rate >30
Urgent: nonambulatory, do not meet other criteria
Not urgent: anyone who can walk
Dead: not breathing
Dying: patients determined to be beyond help
|Open airway || |
Based on START and SAVE triage
Category for Dying created so they can receive comfort care
Uses geographic triage with flags rather than individual tags
|Triage Sieve || |
Priority 1 (immediate): red
Priority 2 (urgent): yellow
Priority 3 (delayed): green
Priority 4 (expectant): blue
Dead white or black
Priority 1: not walking with respiratory rate <10 or >29, or capillary refill >2 s
Priority 2: not walking with a respiratory rate 10-29 and cap refill <2 sec
Dead: no airway
|Open airway || |
|Pediatric Triage Tape (PTT) || |
Immediate: abnormally slow or fast respiratory rate, or abnormally slow or fast pulse rate
Urgent: not walking with a capillary refill of <2 s
Delayed: child who is walking, or an infant who is alert and moving all limbs
Dead: not breathing
|Open airway || |
Requires a tape that uses height of patient to provide age-appropriate vital sign parameters (four sizes of the patient: 50-80 cm, 80-100 cm, 100-140 cm, and >140 cm)
Adaptation of Triage Sieve
|CareFlight || |
Immediate: does not follow commands or no radial pulse
Urgent: does not walk but obeys commands and has a radial pulse
Unsalvageable: not breathing with an open airway
|Open airway || |
|Sacco Triage Method || || ||Open airway, decompress pneumothorax, stop exsanguination || |
Provides a score for each patient; grouping of patients changes with available resources
Transport order by score, not group
|Military Triage || |
Immediate: those who should be treated first, with a list of possible injuries
Delayed: those who can have a delay of 6-8 hours before treatment
Minor: those who will not have significant mortality if no further care is provided
Expectant: those with signs of impending death who require vast resources for treatment
|Open airway || |
|CESIRA || || |
Red: Unconscious, hemorrhaging, in a state of shock, insufficient respirations
Yellow: none of the above with broken bones and other injuries
Green: able to walk
|Not applicable: prehospital providers in Italy may not determine death in the field || |
No dead category, only physicians can declare death in Italy
Based on presenting problem
Name is based on order in which conditions are evaluated
First, we will discuss some of the various measures that existing triage methods utilize in the categorization of patients. Then we will discuss the major triage methods that are in use in the United States, with mention of some valuable points illustrated by other systems.
Again, the goal of an effective triage method is to reduce both under- and overtriage. By using effective measures of injury, such as physiologic and anatomic criteria, rather than using mechanism of injury criteria to categorize patients, studies have shown that we can reduce rates of overtriage without increasing rates of undertriage.5 Such physiologic and anatomic criteria include a Glasgow coma score <14, a systolic blood pressure <90 mm Hg, and a respiratory rate <10 or >29 breaths per minute.
It is generally considered impractical to obtain a blood pressure reading using a sphygmomanometer in the initial triage phase of an event. This is because noisy and dark environments may make it difficult to hear and see well enough to use a blood pressure cuff, and because it is difficult to rapidly obtain such a measure on multiple patients. Therefore, certain surrogate measures of adequate perfusion, including assessment of a radial pulse or capillary refill, are utilized by most existing triage methods. Assessment of radial pulse likely carries the most utility, because it does not require special equipment to measure, and, unlike capillary refill, a radial pulse can be assessed in dark and cold environments.12
Even in normal day-to-day EMS and trauma operations, the calculation of an accurate Glasgow coma score (GCS) may be difficult.12 However, there is good evidence to support the simplification of the GCS in the MCI setting. Dark environments may make it difficult for rescuers to assess a patient's eye response. Barriers to verbal communication, including language barriers, hearing impairment and hearing-related injuries, ambient noise, altered mental status, and endotracheally intubated patients may make it difficult to reasonably assess a patient's verbal response. Fortunately, several studies have shown that the motor score of GCS has highest predictive value for patient outcome.7,13–17 Specifically, removal of the eye score from the total GCS did not lower predictive performance of the GCS. Additionally, although removal of the verbal score did result in statistically significant but mathematically minimal lowering of the performance of the GCS, the authors of the study advocated for the removal of the verbal score because of the aforementioned barriers to achieving a reliable verbal score. Finally, it was noted that the motor score held a near-linear relationship with mortality and was predictive of the need for intubation, admission to the ICU, and disability.7,14 Based on several of these studies, it appears the motor component of the GCS has predictive validity, is easier to use on an MCI/disaster scene, and sufficiently identifies patients in need of immediate intervention or transport to a medical facility.12,16,17
Simple Triage and Rapid Treatment (START) and JumpSTART (a variation of START that accounts for physiologic differences between pediatric and adult patients) are triage methods utilized by several jurisdictions in the United States and abroad. START was developed in 1983 by Newport Beach Fire and Marine Department and Hoag Hospital, Newport Beach, CA, and was updated in 1994. JumpSTART was developed in 1995 by the Miami, FL Children's Hospital and was modified in 2001. These methods are similar in that they first identify all walking wounded and categorize them as “minor” and direct them to a secondary triage area. Next is an assessment of apnea and respiratory rate, followed by assessment of perfusion using either the radial pulse or the capillary refill. Finally is an evaluation of mental status assessed by the ability of the patient to follow commands. Figure 53-1 illustrates a combined START/JumpSTART triage algorithm. Incidents where START was utilized have been retrospectively reviewed for the rate of under- and overtriage. Additionally, the ability of providers to apply the START and JumpSTART methods using paper-based tests has also been assessed, although it is not known how well performance on a paper-based scenario predicts performance in the field.12 With the exception of opening the airway (and providing five rescue breaths for apneic pediatric patients), neither START nor JumpSTART includes any other immediately lifesaving interventions in the protocols. One criticism of the START method is that it appears to undertriage elderly patients.18
TRIAGE SIEVE AND PEDIATRIC TRIAGE TAPE
The Triage Sieve is a method used widely in the United Kingdom and parts of Australia and was developed in 1995 by Hodgetts and Mackway-Jones.19,35 Similar to START, this method assigns priority based on ability to walk, airway patency, respiratory rate, and pulse rate. This method first identifies the walking wounded and categorizes them as Priority 3/Delayed. Then the provider assesses for apnea and rate of breathing, followed by assessment of perfusion by measuring the radial pulse. In difference to START's definition of abnormal breathing as >30 bpm, the Triage Sieve defines abnormal breathing as <10 or >29 breaths per minute. Triage Sieve also defines an abnormal pulse as >120/minute. There is no assessment of mental status or motor function (beyond ability to walk) in this method. Also, except for basic airway opening maneuvers, the protocol does not include other interventions for immediate life threats. Figure 53-2 illustrates the Triage Sieve algorithm.
Similar to JumpSTART being a pediatric adaptation of START, the Pediatric Triage Tape (PTT) is a pediatric adaptation of Triage Sieve. The PTT is “a waterproof, nontear tape that relates the child's height/length to normal physiological variables so that their physiologic status can be assessed using age-appropriate norms.”20,35
Malik et al documented the use of Triage Sieve at a train wreck in Pakistan.21 There is no documentation of the use of the PTT in a real-world situation, although a few papers have assessed its utility using paper-based testing.22 Additionally, attempts were made to validate the PTT using a surrogate data source. Wallis et al assessed the PTT's ability to retrospectively correctly identify pediatric trauma patients presenting to a South African trauma unit that had an Injury Severity Score of >15. They identified that with this population, the PTT had a sensitivity of 38% and specificity of 99%, and if it had been used in a similar real-life situation, rates of overtriage and undertriage would be 39% and 4%, respectively.23
The Homebush Triage Standard was developed in Australia and utilizes START and SAVE. Unlike many response plans in the United States, the Homebush method does not utilize triage tags during the initial categorization of patients, but rather directs them to geographic areas on the disaster scene that have been marked with colored flags representing the different triage/treatment priorities. In addition to the Homebush method classifying patients into Immediate, Urgent, Non Urgent, Dying, and Dead, the method also assigns both a phonetic alphabet priority code (Alpha, Bravo, Charlie, Delta, Echo) and color code (Red, Yellow, Green, White, Black) in order to ensure clear radio communications and easy visual recognition. Like the US National Guideline for Mass Casualty Triage (SALT), the Homebush Triage Standard was suggested in order to establish a uniform method and familiar, common language of triage that all hospitals and ambulance services would utilize and allow for effective and efficient communication.24
The National Disaster Life Support (American Medical Association curriculum) suite of courses teaches a sorting method called MASS (Move, Assess, Sort, Send). This sorting method is adaptable to any of the major triage categorization systems and provides guidance on the process of on-scene evaluation and rapid sorting of patients. Utilizing the principle that patients who can walk and follow a command are likely to be less critically injured, patients who cannot walk but can otherwise move and follow a simple command are more severely injured, and those who cannot move and cannot follow a command are the most severely injured or dead, the MASS method employs a global sorting of patients in order to facilitate the identification of those patients who need to have a triage category of “immediate” ascertained as quickly as possible in order to effect maximal patient survivability.25
Recognizing that several triage methods were being utilized by various jurisdictions within the United States, and the problems inherent with the lack of a uniform standard practice (ie, lack of interoperability, lack of common language, different treatment and transport prioritization, etc) a panel of experts from the private and public sectors was convened in the United States in 2008. The consensus panel identified and reviewed existing triage methods in order to propose a National Guideline for Mass Casualty Triage. As part of their evaluation process, the panel identified “Model Uniform Core Criteria for Mass Casualty Triage.”26 These criteria earned the endorsement of the American Academy of Pediatrics (AAP), American College of Emergency Physicians (ACEP), American College of Surgeons—Committee on Trauma (ACSOT), National Association of Emergency Medical Technicians (NAEMT), National Association of EMS Physicians (NAEMSP), among several others.
In developing these core criteria, they established general criteria thought to be needed for a triage method to be effective (Table 53-2). Additionally, they recognized the need for a method of global sorting, guidelines for the provision of lifesaving interventions, and an algorithm for individual assessment of triage category.
General Considerations for an Effective Mass Casualty Triage Method
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General Considerations for an Effective Mass Casualty Triage Method
|Triage methods and all their components must apply to all ages and populations of patients. |
|Triage methods must be applicable across the broad range of mass casualty incidents where there is a single location with multiple patients. |
|Triage methods must be simple, easy to remember, and amenable to quick memory aids. |
|Triage methods must be rapid to apply and practical for use in an austere environment. |
|Triage methods are resource dependent and the system must allow for dynamic triage decisions based on changes in available resources and patient conditions. |
|Triage methods must require that the assigned triage category for each patient be visibly identifiable (triage tags, tarps, markers). |
|Triage is dynamic and reflects patient condition and available resources at the time of assessment. Assessments must be repeated whenever possible and categories adjusted to reflect changes. |
In addition to these considerations, other authors have suggested that the ideal triage method will also be applicable by rescuers with a variety of backgrounds and levels of experience.7 Key performance characteristics by which triage instruments should be examined to determine a standard guideline for triage that were identified by Armstrong et al include:
Simplicity, for execution in chaos
Time efficiency, when time equals lives
Predictive validity, so that the assessment relates to the intended outcome, namely, the identification of the critically injured from the mass of walking wounded
Reliability, in that it is reproducible (with both the same rater and between raters) across all hazards
Accuracy, to minimize over- and undertriage
After reviewing the various existing triage methods, the consensus panel determined that although several of the triage methods reviewed met some of the Core Criteria, no single method existed that best fit all of the criteria. The panel then chose to design a new triage method: Sort, Assess, Lifesaving intervention, Treatment/Transport (SALT), which incorporates what were identified as the best characteristics of existing triage methods into a singular method that better meets the Core Criteria. It is recognized by the panel that SALT encounters the same limitations that existing methods do, the fact that it is based on Level V (expert opinion) evidence and needs to be validated through various possible methods. Figure 53-3 illustrates the SALT triage method and Table 53-3 defines the SALT triage categories.
SALT triage algorithm. (Reproduced with permission from SALT Mass Casualty Triage. Disaster Med Public Health Prep. 2008;2(4):245-246. Copyright © Society for Disaster Medicine and Public Health, Inc. 2008).
SALT Triage Categories
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SALT Triage Categories
|Treatment/Transport Priority ||Color ||Treatments provided |
|Immediate ||Red ||Lifesaving interventions |
|Delayed ||Yellow ||Analgesics, splinting, basic burn, and laceration care |
|Minimal ||Green ||Basic first aid |
|Expectant ||Gray ||Comfort care, lifesaving interventions if resources become available (recategorized as “immediate” in this instance) |
|Dead ||Black || |
In their invited commentary regarding SALT, Armstrong et al help clarify what SALT does that previous triage methods did not27:
Focuses first on the mass of casualties by voice command sorting. Hearing loss and self-transport of the walking wounded may limit controlled casualty distribution from the scene.
Assesses casualties briefly for explicitly defined lifesaving interventions with applicability in chemical and radiation hazards. Controlling hemorrhage, opening airway, decompressing the chest (for tension pneumothorax), and autoinjection for chemical injury are actions triggered by brief sensory observations.
Separates expectant from dead with a new color, gray. SALT emphasizes the relative nature of the expectant category based on available resources and the need for comfort care. Those casualties who are absolutely unsalvageable are unlikely to move out of the expectant category.
Includes all ages; this instrument applies to adults and children, adding simplicity.
Although SALT has not been evaluated in an actual real-world event, two studies have assessed the ability of paramedics to accurately use the SALT method using paper-based and virtual reality–based examination techniques following an initial training session.28,29
As previously mentioned, secondary and tertiary triage points can help increase the discrimination between critical and noncritical casualties. The Sacco Triage Method, Secondary Assessment of Victim Endpoint (SAVE), and Triage Sort are three methods of secondary triage that have been developed. Converse to the primary triage methods, the secondary triage methods, except for the Sacco Triage Method, have not been investigated for their validity.10
The Sacco Triage Method is a proprietary software–based mathematical model that orders the treatment of patients based on their probability of survival, potential for deterioration, and available resources. This model was based on a set of physiologic scores including respiratory rate, pulse rate, and best motor response. This system is not a triage algorithm and it requires proprietary software, hardware, data entry personnel, communication with incident command or central dispatch, and resource availability reports. It is not designed as a primary triage algorithm, but may be useful when transport/evacuation resources are scarce and on-scene medical care must be prolonged. Additionally, because the method requires the use of proprietary software, it may be difficult for economically challenged jurisdictions to procure and implement. The Sacco Triage Method's use seems to be limited to a few jurisdictions in the United States.10 When compared to other methodology for disaster triage, this method performed well.30 When tested retrospectively this method performed well in pediatric patients.31
Secondary Assessment of Victim Endpoint (SAVE) was developed for use at a casualty receiving area or on a primary scene where significant delays in evacuation to definitive care exist. It is designed to reassess patients and sort them based on survivability within a certain triage category when primary scene operations may be prolonged due to delays in transportation/evacuation of patients.7 SAVE assumes that patients should be classified into one of three categories: (1) those who will die regardless of how much care they receive; (2) those who will survive whether or not they receive care; and 3) those who will benefit significantly from austere field interventions.32 It is to the third subgroup that rescuers should direct limited resources, as they are expected to benefit most from their use.32 The prioritization of patients into a subgroup using the SAVE concept is based on field outcome expectations “derived from existing survival and morbidity statistics.”32 Patients categorized as Immediate (Red) by the START method are assessed using SAVE first, followed by the Delayed (Yellow) and Minimal (Green) groups. Patients subsequently are moved to a treatment area if “1) morbidity or mortality may be reduced with treatment given the estimated time until there is access to definitive care; and 2) Treatment will not consume an inordinate amount of the limited resources and personnel available.”32 Although the remaining patients are initially excluded from receiving treatment, they should be frequently reassessed and moved to a treatment area should their condition change. Patients who are determined to most likely benefit from the earliest available evacuation to definitive care should receive first priority for transport. Table 53-4 outlines the SAVE guidelines.
Secondary Assessment of Victim Endpoint (SAVE) Guidelines
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Secondary Assessment of Victim Endpoint (SAVE) Guidelines
Mangled Extremity Severity Score (MESS) to assess crush injury to extremities
Glasgow coma score <8 in adults with significant head injury
Abdominal trauma with refractory hypotension
Chest trauma with abnormal vital signs
Burns with <50% probability of survival or adults >60 years old with an inhalational injury
Adults with preexisting diseases
Special triage categories such as health care workers with minor injuries who with simple treatment may be able to assist in the medical response
Similar to SAVE, Triage Sort was developed as a secondary triage tool to help establish treatment and transport priorities for patients who have been already categorized by a primary triage method. While SAVE is aimed at on-scene operations where there are limited medical resources and evacuation to definitive care will be delayed, Triage Sort was developed for use on scenes where resources have not been overwhelmed and categorizes patients based on a weighted score that combines the GCS, respiratory rate, and systolic blood pressure.10 Table 53-5 outlines the Triage Sort scoring and prioritization system.
Triage Sort Scoring System
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Triage Sort Scoring System
|Scoring Parameters |
|GCS ||Points ||Respiratory Rate ||Points ||Systolic Blood Pressure ||Points |
|13-15 || 4 ||10-29 || 4 ||>89 || 4 |
|9-12 || 3 ||>29 || 3 ||76-89 || 3 |
|6-8 || 2 ||6-9 || 2 ||50-75 || 2 |
|4-5 || 1 ||1-5 || 1 ||1-49 || 1 |
|3 || 0 ||0 || 0 ||0 || 0 |
|Total score ||1-10 ||11 ||12 ||0 |
|Treatment/transport priority ||Immediate ||Urgent ||Delayed ||Dead |
The utilization of triage tags is variable among the existing triage methods. Although they may allow for rapid visual identification of patients who have already been triaged, there are some disadvantages to their use. Unless deployed with the responding units, triage tags may be unavailable on scene when they are needed. Additionally, most tags are designed with tear-off sections. As patients are retriaged, the design of these tags allow for additional sections to be torn off if their condition deteriorates, but if the patient's condition improves they will require placement of a new triage tag. The SMART tag, made by TSG Associates, works around this problem by providing a tag that can be folded to display a patient's initial triage category, and refolded as the category changes based on the patient's improving or deteriorating condition.33 In addition to issues with recategorization, some tags may be difficult to write on in inclement weather. If on-scene operations must be extended, a single tag may not provide sufficient space to record important care-related information. Advantages to the use of triage tags include the potential for improved patient tracking, especially with tags that incorporate a unique barcode identifier (as long as the facilities that will be caring for the patient have the correct software and hardware to read the barcode). Alternatives to use of triage tags is to sort patients by sending them to physically different areas marked by appropriately colored flags, tarps, or tents on the disaster scene corresponding to their triage category. The Homebush method used in Australia advocates for such geographical sorting over the use of tags.24
In an MCI that occurs on a discrete scene, there may be a need to establish on-scene triage and treatment facilities. Larger-scale MCIs or disasters may occur over a larger geographic area, making a single triage location almost impossible to establish. Such circumstances may necessitate the creation of casualty collection points that can receive patients who “self-triage” as well as from EMS. In many large-scale events, many patients who seek treatment at a hospital do so via self-triage, meaning they arrive at the hospital by such means as private vehicles or public transportation rather than via EMS. If too many patients self-triage to a particular static resource (ie, a hospital or alternative treatment site), the site may become overwhelmed, thus further diluting the pool of available patient care resources, which can unnecessarily result in poorer patient outcomes including higher critical mortality rates. By creating casualty collection points, the emergency response system may help mitigate the effect of self-triage and can at least attempt to maintain control of the assessment, evacuation, and distribution of patients.
Whether establishing operations at the scene of an MCI or at a casualty collection point, similar principles can guide the planning of how the base of operations is set up. Two common factors, regardless of the scene, are the need for an incident command post to be established, and the need to follow the principles of the incident command structure (ICS) outlined in the National Incident Management System (see Figure 53-4).34 For further information regarding NIMS, please see Chapter 74. An Incident Command Post must be established, ideally in an area where access can be controlled but can still maintain a line of sight over critical operating areas such as the Immediate treatment zone and supply depot.
Command structure for various relevant ICS positions utilized during on-scene disaster operations.
Suitable ingress and egress routes must be secured for the arrival and departure of patients and transport vehicles. Treatment zones should be created for each category of the patient: Immediate, Delayed, and Minimal. If resources allow, an Expectant treatment zone may also be established. Deceased patients should be left where they are found at the incident scene in order to avoid disturbing possible criminal evidence and to avoid utilizing resources that are needed to care for and transport salvageable patients.
PRIMARY SCENE/ “GROUND ZERO”
If operations are established at the primary incident site (also known as “ground zero”), initial triage of patients is likely to occur where and when patients are found. As soon as a patient is categorized, they should be directed or assisted toward an appropriate treatment zone. If necessary, patients may be passed through a decontamination point as they are being distributed to their respective treatment zones (see Figure 53-5).
SECONDARY SCENE/CASUALTY COLLECTION POINTS
In some operations, it may be prudent or necessary to set up medical response operations at a location that is remote from the primary incident. Such sites are referred to as casualty collection points, are located in a secured location, and are often in between a primary scene and the locations of static facilities that will provide definitive care. At a casualty collection point, a specific point of triage should be established through which to funnel the flow of patients as they arrive by various means. Again, after a patient has been categorized in triage, they should be directed or assisted toward an appropriate treatment zone. In order to maintain a unidirectional control of flow, points of ingress and egress should be separately established for both arriving and departing vehicles and patients (see Figure 53-6).
Casualty collection point triage.
EVACUATION AND PATIENT DESTINATION CONSIDERATIONS
It should be understood that patients should be evacuated from the treatment zones as quickly as possible. If transport resources are readily available, only immediately lifesaving procedures should be performed on scene. Other interventions can and should be deferred to the destination facility or may be performed in transit. Cotransporting less severely injured patients with those who have more severe injuries (ie, a delayed patient with an immediate patient) may be an effective way to expedite evacuation of patients from the treatment zones, as long as cotransporting patients does not overwhelm the ability of the transporting providers to care for either patient. The goal of the triage, treatment, and transport process should be to evacuate all living casualties from the disaster scene or casualty collection point in a rapid manner. Utilization of alternative sources of transportation, such as public transportation or school buses, may be useful to evacuate and transport a large number of “minimal” patients in an environmentally controlled and secure vehicle, helping prevent added morbidity from prolonged environmental exposure. When possible, efforts should be made to cotransport members of a family, especially when the family consists of young children, elderly adults, or those with special needs who may need a family member to serve as a guardian and representative.
The evacuation of patients from a scene or a casualty collection point must be done with knowledge of how the static care centers and hospitals are functioning based on their ability to operate following the event. This is true both with regard to the operational status of the hospitals' physical plants, but also with regard to the patient volumes they are receiving both from “organized” response systems and those patients who have self-triaged to the hospital.
The geographic effect refers to the premise that the hospital closest to the scene is often inundated with patients, which impairs their ability to effectively manage the number of casualties they are receiving.5 By instituting a process called leap frogging, patients are diverted past the nearest treatment facility to other nearby hospitals, thus helping provide a more orderly and equitable distribution of patients among the available health care centers.5
THE EMS PHYSICIAN AND MCI/DISASTER OPERATIONS
In most circumstances, EMS providers who are active in the field at the time of the incident response will establish initial on-scene operations. However, as the nature of the incident is better understood and operational needs are defined, the presence of additional medical providers and supervisory personnel may be requested to the scene. The EMS physician(s) may be one of the resources that are called upon to provide on-scene assistance, although their exact on-scene role may differ depending on the situational needs. Potential EMS physician roles may include aspects of secondary triage, direct treatment, or to serve as an oversight/expert consultant.
We use caution here, to carefully define this physician role as one that should be filled by an EMS physician, that is, a doctor who has special training and knowledge in EMS and disaster field operations. Other physicians may be useful as on-scene medical providers, but only if they are capable of following specific instructions from the command structure.
Where and how the EMS physician is deployed may depend on the immediate needs of the scene, and as such, the deployment role may need to adapt as on-scene circumstances change.
THE EMS PHYSICIAN AS A SECONDARY TRIAGE OFFICER
In some cases, the EMS physician may best serve in a role as the triage officer. In the French disaster management response system, the Red and White Plans, a specially trained prehospital physician is dispatched to serve as the triage officer at a casualty collection point. The difference in the French Triage Method that makes a physician valuable in this role is that the system categorizes patients as absolute emergencies and relative emergencies, with a subsequent stratification of extreme emergency (EE), or first emergency (U1), second emergency (U2), and third emergency (U3). Each category is defined by a list of specific diagnosis such as cardiopulmonary failure (an EE), hemorrhagic gluteoperineal injuries (U1), compensated chest injuries, and head injures with a GCS >12 (U2), among others. This diagnosis-based stratification requires a sophistication of knowledge and experience that most EMS providers would not have, but that an EMS physician likely would.7
In a modification of the French approach, the EMS physician may serve well as a secondary triage officer in the “Immediate” and possibly the “Delayed” treatment zones. In this circumstance, the EMS physician(s) can utilize their more in-depth understanding of pathophysiology and injury management to help establish treatment and evacuation priorities for patients within each treatment zone. In this role, the EMS physician may serve as the secondary triage/treatment zone officer, or may serve a consultatory role to the EMS provider who is acting as the secondary triage/treatment zone officer.
THE EMS PHYSICIAN AS A TREATMENT PROVIDER
An alternative deployment of the EMS physician may be to serve as a treatment provider in the “Immediate” or “Delayed” treatment zones and become directly involved with patient care (Figure 53-7). In this role, the physician can perform simple lifesaving or life-maintaining interventions such as tube thoracostomy or hemorrhage control via vascular ligation. Obviously these interventions should be performed based on the availability of supplies and resources, and unless needed as an immediate lifesaving intervention, should not be performed if they will delay the patient's evacuation to definitive care. Other non-EMS physicians who self-respond to a scene or are uninjured/minimally injured casualties may also be useful as treatment providers in the Immediate and Delayed treatment zones. The caveat with utilizing any physician to provide or direct treatment for patients in a treatment zone is that they must recognize the limitations for immediate and ongoing care that exist in the given scene. It may be difficult for non-EMS physicians to recognize that a patient is not salvageable, and that other patients may benefit from the resources that could be expended trying to save an unsalvageable patient.
EMS physicians may augment triage and/or treatment roles. (Photo courtesy of Upstate Medical University Hospital, Syracuse, NY. Photographer: Robert Mescavage.)
THE EMS PHYSICIAN IN AN OVERSIGHT ROLE OR EXPERT CONSULTANT
The advanced training, knowledge, and experience possessed by an EMS physician may make them most useful to serve a role in the Command Post to assist with scene oversight and/or as an expert consultant to the incident commander. As previously mentioned, the EMS physician may also be useful in a treatment zone by serving as an expert consultant, directing the care being provided by other treatment providers (such as non-EMS physicians), but not becoming involved in directly providing patient care themselves.
Regardless of the role of the EMS physician on scene, care should be taken for their role to be clearly defined and maintained. Although the role may evolve over time, switching frequently between different roles will likely decrease the effectiveness of the EMS physician on scene and overwhelm the physician's capabilities. The EMS physician's role should be task oriented and follow the tenets of ICS/NIMS, especially with regard to maintaining span of control.
The World Medical Association provides excellent summary statements regarding the role of any physician in disaster response3 :
It is ethical for a physician not to persist, at all costs, in treating individuals “beyond emergency care,” thereby wasting scarce resources needed elsewhere. The decision not to treat an injured person on account of priorities dictated by the disaster situation cannot be considered a failure to come to the assistance of a person in mortal danger. It is justified when it is intended to save the maximum number of individuals. However, the physician must show such patients compassion and respect for their dignity, for example, by separating them from others and administering appropriate pain relief and sedatives.
The physician must act according to the needs of patients and the resources available. He/she should attempt to set an order of priorities for treatment that will save the greatest number of lives and restrict morbidity to a minimum.
Triage has been an evolving process that has developed over centuries into a dynamic system that has adapted to advances in the technology of war, the understanding of disease and injury, and in medical science and technology. We recognize that our current triage strategies are based mostly on “expert opinion,” and as such existing methods have inherent flaws and shortcomings. The effort put forth by the panel that developed the US National Guideline for Mass Casualty Triage has been an excellent step toward establishing an evidence-based approach to triage methods and practices. Ongoing research, including postevent analysis of triage decisions and casualty outcome analysis, as well as evaluation of provider training techniques and provider knowledge retention must be pursued. Such efforts will further guide us in the development and refinement of a comprehensive all hazards triage standard that is interoperable, universal, validated, and maximizes patient survival. The EMS physician plays a key role in ongoing response planning, integration of EMS with other disaster response entities, and the advancement of the science of triage through research. As the science of triage progresses, we recognize that MCIs and disasters will continue to occur. We must remain flexible in our ability to “improvise, adapt, and overcome” as we rise to meet the challenges encountered during future disaster responses.
Triage is a dynamic process, not a finite moment in time or a static process. It must occur at several steps between the onset of the incident to the final disposition of the patient.
The EMS physician should advocate for the adoption of uniform standards of triage to ensure interoperability between agencies and jurisdictions on the local, regional, state, federal, and international levels.
The EMS physician may play several important roles in the triage process including response planning and resource integration, as an active participant in on-scene response, and in postincident recovery.
Resource availability and capability are limiting factors in the care provided during multiple casualty, mass casualty, and disaster incidents.
EMS physicians should embrace their important role in the advancement of the body of knowledge related to triage practices. Using this knowledge, processes can be developed to validate triage methods so we can optimize our ability to provide the most benefit to the most patients.
A brief history of triage. Disaster Med and Public Health Prep. 2008;2(suppl 1):S4–S7.
Clinical pearl—disaster and mass casualty triage. Am Med Assoc J of Ethics. 2010;12(6):466–470.
Triage: principles and practice. Scand J Surg
Disaster triage for large-scale catastrophic events. Disaster Med and Public Health Prep. 2008;2(suppl 1): S35–S39.
Mass casualty triage in the chemical, biological, radiological, or nuclear environment. Eur J Emerg Med
A review of triage and management of burn victims following a nuclear disaster. Burns
Medical management of disasters and mass casualties from terrorist bombings: how can we cope?
. 2002;53: 201–212.
Mass casualty triage: time for an evidence-based approach. Prehospital and Disast Med. 2008;23(1):3–8.
Statistics for Epidemiology. Boca Raton, FL: CRC Press; 2004.
Mass casualty triage: an evaluation of the data and development of a proposed national guideline. Disaster Med and Public Health Prep. 2008;2(suppl 1):S25–S34.
The Glasgow coma scale: to sum or not to sum?
Improving the Glasgow coma scale score: motor score alone is a better predictor. J Trauma
Initial emergency department trauma scores from the OPALS Study: the case for the motor score in blunt trauma. Acad Emerg Med
Comparative analysis of multiple casualty incident triage algorithms. Ann Emerg Med
Field triage of trauma patients based upon ability to follow commands: a study in 29,573 injured patients. J Trauma. 2001;38:129–135.
A better START for low-acuity victims: data-driven refinement of mass casualty triage. Prehosp Emerg Care
Major Incident Management and Support: The Practical Approach. London: BMJ Publishing; 1995.
Pediatric triage tape. Prehosp Immediate Care. 1998;2:155–159.
Triage and management of mass casualties in a train accident. J Coll Physicians Surg Pak
In ‘big bang' major incidents do triage tools accurately predict clinical priority?: a systematic review of the literature. Injury
Validation of the paediatric triage tape. Emerg Med J
An Australian mass casualty incident triage system for the future based upon triage mistakes of the past: the Homebush Triage Standard. Aust NZ J Surg. 1999;69:603–608.
Model uniform core criteria for mass casualty triage. Disaster Med and Public Health Prep. 2011;5:125–128.
Toward a national standard in primary mass casualty triage. Disaster Med and Public Health Prep. 2(suppl 1):S8–S10.
Paramedic accuracy using SALT triage after a brief initial training. Prehosp Emerg Care
Comparison of the SALT and smart triage systems using a virtual reality simulator with paramedic students. Eur J Emerg Med
Head-to-head comparison of disaster triage methods in pediatric, adult, and geriatric patients. Ann Emerg Med. June 2013;61(6):668–676.e7.
Independent application of the Sacco Disaster Triage Method to pediatric trauma patients. Prehosp Disaster Med. August 2012;27(4):306–311.
Disaster triage: START, then SAVE—a new method of dynamic triage for victims of a catastrophic earthquake. Prehosp Disas Med. 1996;11(2):117–124.