Emergency Response and Trauma System Access
A critical function of the regional trauma system is to ensure that all injured patients within its geographic boundaries have access to definitive care to meet their injury needs. Access to the trauma system is dependent on the availability of prehospital transport services, the proximity and availability of definitive care resources, and the processes that direct the injured patient to definitive care. Ideally, the geographic distribution of trauma centers matches the population distribution and prehospital resources are organized such that timely access to the trauma center is ensured independent of distance. In 2005, it was estimated that 69.2% of US residents could access a major trauma center within 45 minutes and 84.1% could access one within 60 minutes of injury.36 The remainder lived primarily in rural areas and states with the most urban populations had the highest proportions that could access a trauma center within an hour. More current data estimates that 63.1% of the US population can reach a major trauma center within an hour by ambulance and the inclusion of helicopter services increased this proportion to 90.4%. The University of Pennsylvania, in consort with the American Trauma Society and with support of the US Department of Health and Human Services manages a comprehensive website (http://www.TraumaMaps.org) which is periodically updated and provides a continuous overview of trauma system coverage in the United States.
Prehospital Triage and Transport
Access to trauma care is not only dependent on the availability of EMS and hospital physical resources, but also the processes that govern the delivery of the patient to definitive care. Triage is the process by which injured patients are sorted to ensure that each has timely access to the appropriate level of care based on medical need and availability of resources. A critical function of the regional trauma system is to triage major trauma patients to major trauma centers. This often requires bypass of a closer hospital in favor of a trauma center for major trauma patients. Triage should be selective so that medical resources are allocated to the patients that will realize the most benefit. Triage is a dynamic process that occurs continually at every phase of patient contact. Initial triage decisions are often revised as more information becomes available. Triage priorities may also be modified based on the balance between demand and availability of medical resources as in mass casualty scenarios.
Defining the major trauma patient
There is no standard that defines the major trauma patient. In practice, identification of the major trauma patient depends on the clinical context where differentiation is needed. In the prehospital setting differentiation is needed to determine which patients should be transported directly to the trauma center and is often based on physiologic, mechanism, and patient factors. In the acute care setting differentiation must identify the population that falls within the trauma program’s scope of practice. This may be based on injury pattern, use of specialized resources, or standardized registry inclusion criteria. Retrospective differentiation is necessary to assess trauma system performance and is often based on a mortality prediction thresholds derived from discharge diagnoses and often from secondary data sources. The major trauma patient is defined differently in each context which can make generalizations beyond a specific context problematic. What is apparent acutely in the field and what has been determined by discharge can be very different.
Prehospital Identification of The Major Trauma Patient Using Limited Information
The challenge of trauma triage is to anticipate definitive care needs using limited information available at the time when triage decisions must be made. Of all trauma patients, only 7–15% have injuries that will require the resources of a major trauma center. Although clinical recognition of the major trauma patient is usually straightforward, serious, even life threatening, injuries are sometimes occult and not discovered until after a comprehensive work up. Because mistriage is inherent, triage must be viewed as a continuous, flexible, and error tolerant process with contingencies for mistriage.
Primary or field triage directs transport from the scene to the highest level of care within a reasonable transport distance for major trauma patients. This usually enables rapid transport directly to major trauma centers in urban and suburban environments. Because the extent of injury is not always evident in the field, prehospital triage guidelines are established to identify patients at risk for severe injury and aid prehospital decision making. These tools are designed to be simple and applied broadly; the main purpose is to determine if the patient’s estimated risk warrants transport to the nearest major trauma center rather than the nearest hospital. Risk of severe injury is estimated using information based on physical examination, mechanism characteristics, and pre-injury patient characteristics easily obtained by EMS on initial patient contact. Criteria for field triage are ordered with physiologic derangements indicating highest risk followed by anatomic findings, energy transfer mechanisms, and pre-injury patient comorbidities in decreasing order.
Brief Review Of Methods Proposed for Field Triage Scoring
To be useful in the field, a triage protocol must meet certain criteria.37 The components of the scoring scheme must be credible, and have some correlation with the injuries being encountered. The triage scoring method must correlate with outcome, although its primary purpose is identification of immediate patient risk. The better the correlation with outcome, the lower the undertriage and overtriage rates within a trauma care system. Outcomes for major trauma victims are usually classified as death, need for urgent/emergent surgical intervention, length of intensive care unit (ICU) and/or hospital stay, and major single-system or multisystem organ injuries.
The scoring scheme must also have interobserver and intraobserver reliability, that is, it should be able to be consistently applied between observers and by the same observer at another point in time with the same results, recognizing that the patient may have changed as a result of injury or therapy over time. Finally, the scoring scheme must be practical and easily applied to trauma victims for a variety of mechanisms, by a variety of personnel without the need of specialized training or equipment.
While most of the field triage criteria are based on physiologic criteria, there are other methods for assessing the severity of the potential injury to a trauma victim. As shown earlier in the chapter, mechanism of injury, anatomic region and type of injury, preexisting illnesses, and paramedic judgment are important considerations in providing additional information in the field to help determine whether a patient requires transport to a designated trauma center. Combination field triage methods make use of this additional information by including it in the initial evaluation of the trauma victim. As trauma systems have evolved, the determination of which variables are most effective in attaining the accuracy required for optimal system function has resulted in numerous proposed methods. Table 4-3 lists a brief history of some of these approaches. All were designed to assist rescue personnel in determining which patient required transport to a trauma center.38,39,40,41,42,43,44 The Pediatric Trauma Score (PTS) is the only one developed specifically for assessment of children.45 As the work detailed in Table 4-3 developed, the ACSCOT, in collaboration with the CDC compiled all of this experience into a single process and developed the ACS Field Triage System. This is a more complete, advanced triage scoring scheme that is described in the Resources for Optimal Care of the Injured Patient, and reflects years of productive collaboration with the CDC.
TABLE 4-3Review of Proposed Triage Protocols |Favorite Table|Download (.pdf) TABLE 4-3 Review of Proposed Triage Protocols
|Method ||History ||Components ||Status ||Ref. |
|Trauma index ||First reported in 1971 by Kirkpatrick and Youmans ||Blood pressure, respiratory status, central nervous system (CNS) status, anatomic region, and type of injury || |
Some correlation with injury severity
Never saw widespread use
|46, 47, 48 |
|Glasgow Coma Scale ||Teasdale and Jennett first introduced ||Eye opening, motor response, verbal response ||Intended as a description of the functional status of the CNS, not as a prehospital assessment tool motor component of the GCS is almost as good as the TS and better than the ISS in predicting mortality ||49 |
Described in 1981 as index
Respiratory rate, Respiratory effort,
SBP, capillary refill, GCS
Central idea was that the leading causes of traumatic death were related to dysfunction of the cardiovascular, respiratory, and CNS
|50, 51, 52, 53, 54, 55 |
Revised Trauma Score
Respiratory effort added 1982
Components of final revision (RTS)
Revised in 1989 because of concerns about accurate assessment of capillary refill and respiratory effort
|Crams Scale ||Proposed as a simplified method of field triage ||Circulation, respirations, abdomen, motor, speech || |
Retrospective and prospective studies indicate that CRAMS triage is accurate in identifying major trauma victims with high specificity and sensitivity.
Easy to use
|56, 57 |
|Prehospital Index ||Introduced in 1986 as field triage tool || |
Blood pressure, Pulse
Level of consciousness
|PHI accurate in predicting the need for lifesaving surgery within 4 h and death within 72 h following injury ||58 |
|Trauma Triage Rule ||Proposed by Baxt et al 1990 || |
GCS motor response
Anatomic region Type of injury
Major trauma victim identification sensitivity and specificity of 92%
Reduced overtriage while maintaining an acceptable undertriage rate
Not widely adopted
|Pediatric Trauma Score (PTS) ||Introduced 1985, Designed to follow ATLS initial assessment scheme ||Patient size, level of consciousness, airway patency, SBP, long bone fracture, open wound ||Still in use throughout world, frequently as risk adjuster in outcomes research ||45 |
Current Triage Recommendations
Since 1986, the ACSCOT has provided guidance for the field triage process through its “Field Triage Decision Scheme.” This guidance was periodically updated in 1986, 1990, 1993, and 1999. In 2005, CDC, with financial support from the National Highway Traffic Safety Administration, collaborated with ACSCOT to convene the initial meetings of the National Expert Panel on Field Triage to revise the decision scheme, which was published in 2006 by ACSCOT as part of Resources for the Optimal Care of the Injured Patient: 2006. In 2009, CDC published a detailed description of the scientific rationale for revising the field triage criteria R2t. CDC reconvened the Panel in 2011 to review the 2006 guidelines in the context of recently published literature, assess the experiences of states and local communities working to implement the guidelines, and recommend any modifications to these guidelines.60
As has been the case from the beginning, the intent of these triage guidelines is to assist prehospital care providers in determination individual injured patients who would benefit from specialized trauma center resources. The process is designed to guide assessment of an individual patient and is not intended as a triage tool to be used in a situation involving mass casualties or disaster. Based on the extensive history of critical thinking, evaluation, review and revision detailed above, the current recommended process of assessment proceeds in four phases (Fig. 4-4).
CDC triage protocol. (Reproduced from Centers for Disease Control and Prevention. Guidelines for Field Triage of Injured Patients: Recommendations of the National Expert Panel on Field Triage, 2011. MMWR 2012;61(1):1. Adapted with permission from American College of Surgeons Committee on Trauma. Resources for Optimal Care of the Injured Patient. Chicago: American College of Surgeons; 2006.)
*The upper limit of respiratory rate in infants is >29 breaths per minute to maintain a higher level of overtriage for infants
†Trauma centers are designated Level I -IV, with Level I representing the highest level of trauma care available.
§Any injury noted in Steps Two and Three triggers a “yes” response.
¶Age <15 years.
**Intrusion refers to interior compartment intrusion, as opposed to deformation which refers to exterior damage.
††Includes pedestrians or bicyclists thrown or run over by a motor vehicle or those with estimated impact >20 mph with a motor vehicle.
§§Local or regional protocols should be used to determine the most appropriate level of trauma center; appropriate center need not be Level I.
¶¶Age >55 years.
***Patients with both burns and concomitant trauma for whom the burn injury poses the greatest risk for morbidity and mortality should be transferred to a burn center. If the nonburn trauma presents a greater immediate risk, the patient may be stabilized in a trauma center and then transferred to a burn center.
†††Injuries such as an open fracture or fracture with neurovascular compromise.
§§§Emergency medical services.
¶¶¶Patients who do not meet any of the triage criteria in Steps One through Four should be transported to the most appropriate medical facility as outlined in local EMS protocols.
Step One: Physiologic Criteria
The first step is rapid identification of critically injured patients by assessing level of consciousness (Glasgow Coma Scale [GCS]) and measuring vital signs (systolic blood pressure [SBP] and respiratory rate). Vital sign criteria have been used since the 1987 version of the ACS Field Triage Decision Protocol. These criteria demonstrate high predictive value for severe injury. Of 289 references identified from the CDC panel’s structured literature review, 82 (28%) were relevant to Step One. SBP less than 90 and respiratory rate less than 10 or greater than 29 remain significant predictors of severe injury and the need for a high level of trauma care. Multiple peer-reviewed articles published since 2006 support this threshold.
Recommended criteria for transport the highest level of care are
Glasgow Coma Scale less than or equal to 13
SBP of less than 90 mm Hg
Respiratory rate of less than 10 or greater than 29 breaths per minute (<20 in infant aged <1 year), or need for ventilatory support
Step Two: Anatomic Criteria
The second step considers that certain patients may initially manifest normal physiology but have an anatomic injury at risk of rapid deterioration and therefore may require the highest level of care. Of the 289 references reviewed by the panel, 57 (20%) were relevant to step two.
Current recommendations for transport to a facility that provides the highest level of care include
All penetrating injuries to head, neck, torso, and extremities proximal to elbow or knee
Chest wall instability or deformity (eg, flail chest)
Two or more proximal long-bone fractures
Crushed, degloved, mangled, or pulseless extremity
Amputation proximal to wrist or ankle
Open or depressed skull fractures
Step Three: Mechanism of Injury
Step three addresses mechanism of injury from the perspective of assessment of magnitude and vectors of force. An injured patient who does not meet step one or step two criteria should be evaluated in terms of mechanism of injury (MOI) to determine the potential for severe but occult injury. Evaluation of MOI will help to determine if the patient should be transported to a trauma center.
Step Four: Special Considerations
In the fourth step, EMS personnel must determine whether persons who have not met physiologic, anatomic, or mechanism steps have underlying conditions or comorbid factors that place them at higher risk of injury or that aid in identifying the seriously injured patient. Persons who meet step four criteria might require trauma center care. A retrospective study of approximately one million trauma patients indicated that using physiologic (step one) and anatomic (step two) criteria alone for triage of patients resulted in a high degree of under triage, implying that using special considerations for determining trauma center need helped reduce the problem of under triage.46 Among 89,441 injured patients evaluated by EMS providers at six sites, physiologic, anatomic, and mechanism of injury criteria identified 4049 (70.8%) patients with an ISS greater than 15; step four of the guidelines identified another 956 (16.7%) of seriously injured patients, with increase in overtriage from 25.3% to 37.3%.60
“Internal” triage and the trauma resuscitation team
The hospital response to prehospital notification is tiered to match the initially assessed level of need. Most severely injured patients require full team activation with all members, including surgeons, immediately responding. Less severely injured may need a partial resuscitation team response, while other patients may be transported to trauma center, evaluated by an emergency physician, and the resuscitation team or other specialty services consulted as needed. The overarching factor governing this process is patient need. It must be counterbalanced, however by the fact that unnecessary mobilization of expensive resources robs them from other critical missions and is often unnecessarily wasteful.61 Thus, the process of internal triage is predicated on how well a trauma center can balance its extensive and expensive resources against patient need and logistical reality. The process may vary among centers and reflect unique capabilities or services available at different institutions. The most recent edition of the Resources for the Optimal Care of the Injured Patient: 2006 includes ACSCOT recommendations regarding major resuscitation criteria. Regardless of how the internal triage process is developed, it must be data driven, continuously assessed and support the overall effectiveness of the trauma system.
Secondary (interfacility) triage
Secondary or interfacility triage directs transfer of patients whose needs exceed the capabilities of the initial receiving facility to a higher level for definitive care. This commonly occurs when patients who do not meet primary triage criteria are transported to a minor trauma center or community hospital and are subsequently found to have injuries are beyond the capabilities of the initial receiving facility.62,63 In remote or rural environments, secondary triage serves to connect minor trauma centers to the major trauma centers after providing initial evaluation and stabilization of the major trauma patient. Like the field triage guidelines, interfacility (secondary) transfer guidelines aim to identify patients at high risk of morbidity or mortality based on injury patterns who might benefit from treatment at a trauma center and recommend early transfer. Occasionally, patients that meet neither field triage nor secondary transfer guidelines are found to have injuries that exceed the capabilities of the initial treating facility. The Emergency Medical Treatment and Labor Act (EMTALA) intends that such patients have access to a higher level of care.
Measuring Triage Accuracy
The regional trauma system’s ability to deliver the right patient to the right place at the right time and make the best use of available resources is expressed as triage accuracy.64 Mistriage (overtriage and undertriage) occurs when a patient triage decisions are not commensurate with their clinical needs. Triage accuracy is dependent on compliance with established triage tools and the ability of those tools to predict the outcome of interest. Since triage is a continuous, dynamic process, opportunities for mistriage can occur during any phase of injury care. Field triage destination decisions are made using the best information available at the time. Inhospital triage and trauma resuscitation team activation decisions are made using the information provided from the field. Secondary triage and interfacility transfer decisions are made with more complete information but are influenced by the availability of resources at the referring facility. At any point, early decisions may appear to have been incorrect once more information is obtained. Consequently retrospective evaluation of early decisions, using more information than was available at the time, introduces inherent methodological mistriage. This error is worsened when real-time time identification of a major trauma patient using a field triage tools is evaluated using a different retrospective definition of a major trauma patient based on another system such as injury severity scoring or a mortality prediction model. Thus what looks like mistriage in part maybe the combined effects of the retrospective evaluation of real-time decisions using disparate definitions.
Overtriage is a triage decision that incorrectly classifies a patient as needing a trauma center but retrospective analysis suggests that such care was not needed, and undertriage is a triage decision that classifies a patients as not needing trauma center when, in fact, they do. While intuitive, operationalizing these definitions into objective quality metrics is problematic. There is no retrospective standard that defines which patients need trauma centers, and which do not. The term “severe injury” is commonly used to refer to patients that need trauma centers and is often applied based on meeting an injury severity score or mortality prediction threshold or consuming specific hospital resources such as operative or ICU care. This assumes that all patients and only patients that meet these definitions require trauma center care. In reality, there are many patients that do not meet such definitions but need major trauma center care, typically because definitive care resources may not be available in the community. Likewise, there are many patients who meet these definitions that may receive high quality injury care at in minor trauma centers or community hospitals.
Equivocation of terms when expressing over or under triage rates also complicates trauma systems research. For example, the field undertriage rate could be expressed as the number of major trauma patients that did not receive the highest level of trauma team activation relative to the total number of trauma team activations. It could also be expressed relative to the total number of major trauma patients or relative to the total number of all injured patients. Each conveys important but different information; the first reflects the proportion of trauma team activations that were under triaged, the second the proportion of major trauma patients that were under triaged, and the last the proportion of all patients that were under triaged. The same issues occur with equivocation of overtriage terms. The need to differentiate field triage, which reflects primary destination decisions, and system triage, which reflects the final patient distribution within the system further complicates terms since over and under triage occurs at both the field and system levels.
An approach to minimize equivocation of terms is to apply standard contingency table terminology to both field and system triage (Table 4-4). Given that triage accuracy is the number of patients appropriately triaged relative to the total number of patients, then inaccuracy or mistriage is the number of inappropriately triaged patients relative to the total. Since mistriage is a reflection of both over and under triage, then 1 = accuracy + overtriage + undertriage. Here accuracy, overtriage, and undertriage have precise meanings at both the field and system levels. Sensitivity, specificity and positive and negative predictive values convey meaningful information at the field level since field triage is expected predict major trauma but less so at the system level the distribution of low and high risk patients between major trauma centers and other hospitals is described. Utilization refers to the proportions of low- and high-risk patients discharged from major trauma centers and other hospitals.
TABLE 4-4Definition of Terms for Field and System Triage
The study of triage accuracy is conceptually, linguistically, and technically complex. Together field triage, secondary transfer, and EMTALA regulations, and the role of major trauma centers as large community hospitals influence access to resources in the regional trauma system. Application of these regulations and the hospital capabilities determine the final distribution of injured patients. Inherent methodological errors introduced by retrospective evaluation of treatment decisions, equivocation of terms, and generalizations between phases of triage must be taken into account when making conclusions on overall triage performance and setting system triage benchmarks.
Terrorism is the emerging weapon of modern civil strife. Terrorism events now occur almost weekly in various countries around the world, and are usually designed to inflict as much damage as possible to innocent bystanders and then to strike again when rescuers arrive. Manmade events such as these and natural disasters such as Katrina (New Orleans), Superstorm Sandy (New Jersey and New York), and the endless stream of floods and devastating tornados that seem to increase in frequency with every passing year should crystallize the resolve of all medical personnel to become educated and proficient in disaster management. The approach to disasters, whether natural or manmade, requires a coordinated relief effort of EMS, hospital, fire, police, public works personnel, and often the military. This multiorganizational operation can effectively manage a crisis only if it is well directed and controlled. The ability to assess a disaster scene, summon appropriate personnel to provide damage control, fire management, rescue operations, and crowd control is dependent on an organization structure that permits dynamic information processing and decision making based on adequate planning and accurate vital scene information.
The military uses the concept of command and control for its combat operations. Key personnel continually monitor and manage the battlefield situation. The Fire Service of the US Department of Forestry, in 1970, adapted command and control into an incident command structure. Within this framework, a centralized group of disaster personnel commands and controls all of resources at the disaster site. Dynamic disaster scene information is processed at a predesignated incident command center where decisions regarding deployment and mission of rescue resources are implemented.
The incident command center structure is composed of seven key groups. If the disaster is small in scope, a single person may fill all seven areas. As the disaster increases in scope, more personnel are required to fulfill these functions. The incident commander is responsible for the entire rescue or recovery operation. Under the direction of the incident commander are the seven group commanders: operations, logistics, planning, finance, safety, information, and liaison. Each of these section commanders has well-defined areas of authority and responsibility. Continuous on-scene information will be communicated to the command center. This will enable the incident command center to plan and direct the rescue or recovery operation. Thus, limited resources and key personnel will be directed to produce the greatest benefit.
The disaster scene is typically divided into zones of operation. Ground zero is the inner hazard zone where the fire and rescue operations occur. EMS and other nonessential personnel are kept out of this area. Rescued victims are brought out of this area to the EMS staging area. This is the second zone, a primary casualty receiving area, and it is here that EMS personnel perform triage and initial care for the patient. Disposition directly to the hospital may occur or the patient may be sent to a distant receiving area for care and ultimate triage and transport.
The distant casualty receiving areas provide for additional safety in the environment. This downstream movement of injured patients prevents the primary triage sites from being overrun. Transportation of the wounded from the primary receiving site is reserved for the most seriously injured patients. Thus, a tiered triage approach is developed. A temporary morgue is also set up at a distant site.
Typically, groups of patients, the walking wounded, will migrate toward the nearest medical treatment facility. This process is called convergence. Medical facilities often set up a triage area in front of the emergency department to handle these patients. Current medical philosophy and federal regulations mandate treatment of any patient who arrives at an institution’s emergency department. In mass casualty situations, however this can quickly overwhelm facility function and actually diminish effectiveness of care for all patients. Appropriate community disaster planning must recognize this potential problem and establish processes to direct certain groups of these patients to secondary medical facilities. The use of outpatient surgery centers, which are proliferating throughout the country may be a valuable resource for this purpose. The final operational zone of the disaster site is the outer perimeter. Police permit only essential personnel access into the disaster site. Crowd and traffic control ensure the safety and security of the disaster scene as well as to provide emergency vehicles rapid transit to and from the site.
Disasters may be of a small scale such as a building fire or explosion and may remain only a local or regional problem. As was demonstrated in the wake of the World Trade Center attack and Superstorm Sandy, the magnitude of a local disaster was of such proportions that activation of the National Disaster Medical System was necessary to address the rescue and recovery efforts. Analysis of more recent natural disasters demonstrates that approximately 10–15% of the survivors were seriously injured. The remaining victims either were dead or had mild to moderate trauma. Thus, overall effectiveness of disaster response is predicated on rapid sorting of survivors to determine the level of care needed by each patient.
In managing the World Trade Center attack, the New York Fire Department and EMS utilized the START system. The initial scene casualties were from the planes striking the building. Fire and rescue personnel could not reach these patients. With the collapse of the first tower, rescue operations were aborted and attempts to evacuate rescue personnel became paramount.65 After the building collapsed, victims injured in the street or from the surrounding buildings required medical treatment. As rescue operations resumed, injured rescue workers began to arrive at medical treatment facilities. Unfortunately, there were only five survivors of the Twin Tower collapse with over 3000 fatalities, which included civilians and rescue personnel.
Israel’s experience with terrorist attacks has demonstrated that rapid and accurate triage is critical to decrease or minimize mortality. Therefore, it has been suggested that the best triage officer, at least in bombings and shooting massacres, which are the most common form of terrorist violence, is the trauma surgeon. This is important to guarantee that those in real need of immediate surgical attention are seen and treated in a timely fashion without inundating the hospitals with patients who can be treated at a later time.
Many critical concepts have been learned from the Israeli experience. These include rapid and abbreviated care, unidirectional flow of casualties, minimization of the use of diagnostic tests, and relief of medical teams every so often to maintain quality and effectiveness in care delivery. The concepts of damage control should be liberally applied in the operating room (OR) to free up resources for the next “wave” of injured individuals.66,67,68,69 During mass casualty events, hospitals become overwhelmed very easily. Therefore, communication between hospitals is critical to distribute the casualties evenly. All surgeons should be familiar with the basic principles of mass casualty management, and trauma surgeons should be the leaders in this field, since trauma systems serve as a template for the triage, evacuation, and treatment of mass casualty victims.70
Application of Triage Principles for Multiple Patient Victim Events
Identification of the degree of injury severity that will determine need for transport to a trauma center is the core mission of every triage protocol ever devised. When there are hundreds of patients, however, a completely different process of patient assessment must be deployed. Triaging a single trauma victim is relatively straightforward as described previously. For multiple casualty incidents, such as seen with multiple cars involved in a large scale crash, the same essential principles apply; however, decisions must be made in the field as to which patients have priority. A multiple casualty incident (MCI) can be defined as any situation where the volume of patients with injury severity may exceed hospital resources. Patients who are identified as major trauma victims by field triage criteria have priority over those who appear less injured. All major trauma patients should be transported to a trauma center as long as the trauma center has adequate resources to manage all the patients effectively. Because this situation can stress local resources, a properly conceived regional or state disaster management plan should include provision for possible diversion of the less critically injured to another trauma center or appropriately equipped hospital. Monitoring transports with online computer assistance allows for contemporaneous determination if one trauma center is overwhelmed.
Triage in this situation is unique in that priorities are different from those in the single- or multiple-victim scenarios. In the instance of mass casualties, the resources of the designated trauma center, as well as the regional trauma system, are overwhelmed. When resources are inadequate to meet the needs of all the victims, priority shifts from providing care to those with the most urgent need to providing care to those with the highest probability of survival. A severely injured patient, who would consume a large amount of medical resources, is now a lower triage priority. Despite the potential salvageability of this patient, the medical resources are focused on other patients who would benefit from advanced medical and surgical care. This method provides the greatest good for the greatest number of people. Field triage in this situation is probably the most difficult to perform as one has to make choices of quantity over quality with very limited amounts of information. These issues are further complicated when dealing with children.71
The most experienced and best-trained personnel available should make these field triage decisions. Physicians may be the best qualified to make these triage decisions; however, if they are the only receiving physicians available, direct patient care should take precedence and triage decisions would fall to other personnel. Patients are identified according to a triage code, based on the severity of injuries and likelihood of survival, and are treated accordingly. Occasionally, there may be an indication for a specialized surgical triage team with the capability to render acute lifesaving care of an injured trapped patient.72 In some disaster scenarios moving intensive care capabilities into a disaster zone may be beneficial when evacuation of patients may be unrealistic due to logistical reasons.
In order to optimize patient care in these situations, it is important for regionalized systems to stage periodic mock disaster drills. These drills allow for the proper training of all individuals who might be involved as well as the identification and correction of potential problems. With increasing terrorist activity, specific triage algorithms have been developed for specific scenarios such as biologic, chemical, radiologic, or blast attacks.73
Disaster Triage: Simple Triage and Rapid Treatment
In the event of a mass casualty or disaster, EMS personnel may utilize the simple triage and rapid treatment (START) triage system initially developed to be used in earthquakes in California. The object of this system is to triage large numbers of patients rapidly. It is relatively simple and can be used with limited training.74 The focus of START is to evaluate four physiologic variables: the patient’s ability to ambulate, respiratory function, systemic perfusion, and level of consciousness. It can be performed by lay and emergency personnel. Victims are usually divided into one of the four groups with color codes according to the timing of care delivery based on the clinical evaluation as follows: (1) green—minor injuries (walking wounded); (2) red—immediate; (3) yellow—delayed; and (4) black—unsalvageable or deceased.
If the patient is able to walk, he or she is classified as a delayed transport, but if not, ventilation is assessed. If the respiratory rate is greater than 30, the patient is an immediate transport. If the respiratory rate is less than 30, perfusion is assessed. A capillary refill of greater than 2 seconds will mandate an immediate transport. If the capillary refill is less than 2 seconds, the patient’s level of consciousness is assessed. If the patient cannot follow commands, he or she is immediately transported; otherwise he or she is a delayed transport. In light of the concerns about the predictive accuracy of capillary refill, some systems link the START method with severity scores: in the immediate category the Revised Trauma Score varies from 3 to 10, in the urgent category it varies from 10 to 11, and in the delayed (nonurgent) group the RTS is 12. Mass casualty triage principles are the same for children and adults. However, differences in physiology, response to physiologic insult, ability to talk and walk, and anatomic characteristics, disaster triage in the pediatric age group is not as straightforward. Whenever possible, decisions regarding disposition of children should include consideration of availability of parental support.
A major benefit of the START system is accurate identification of severely injured trauma patients who may be able to be transported by air or ground ambulances to more distant trauma centers where the lower number of victims will assure that resources are available to provide optimal care.