Trauma, 7th Ed.

CHAPTER 4. Trauma Systems, Triage, and Transport

Raul Coimbra, David B. Hoyt, and Vishal Bansal


A trauma system is an organized approach to acutely injured patients in a defined geographic area that provides full and optimal care and that is integrated with the local or regional emergency medical service (EMS) system.

A system has to achieve cost efficiency through the integration of resources with local health and EMS system to provide the full range of care (from prehospital to rehabilitation).13

Regionalization is an important aspect of trauma as a system because it facilitates the efficient use of health care facilities within a defined geographic area and the rational use of equipment and resources. Trauma care within a trauma system is multidisciplinary and is provided along a continuum that includes all phases of care.26

The major goal of a trauma system is to enhance the community health. This can be achieved by identifying risk factors in the community and creating solutions to decrease the incidence of injury, and by providing optimal care during the acute as well as the late phase of injury including rehabilitation, with the objective to decrease overall injury-related morbidity and mortality and years of life lost. Disaster preparedness is also an important function of trauma systems, and using an established trauma system network will facilitate the care of victims of natural disasters or terrorist attacks. The Model Trauma System Planning and Evaluation Standard has recently been completed by the U.S. Department of Health and Human Services.7


The need for a trauma system seems obvious and intuitive. However, trauma is not yet recognized as a disease process. Many people still think of trauma as an accident. Trauma is an epidemic that affects all age groups with devastating personal, psychological, and economic consequences. Recent calculations have estimated the total cost of injury in the United States to be about $260 billion per year.8

Because of the association of injury and personal behavior, trauma is often predictable and preventable.

The modern approach to trauma care is based on lessons learned during war conflicts. Advances in rapid transport, volume resuscitation, wound care management of complex injuries, surgical critical care, early nutritional management, and deep venous thrombosis prophylaxis were all derived from the military experience.

The American College of Surgeons Committee on Trauma (ACSCOT) was created in 1949 and evolved from the Committee on the Treatment of Fractures that was established in 1922. A specific trauma unit was opened in 1961 at the University of Maryland. In 1966, the National Academy of Sciences and the National Research Council published the important “white” paper entitled Accidental Death and Disability: The Neglected Disease of Modern Society.9The outgrowth of this document was the development and propagation of systems of trauma care. This publication increased public awareness and led to a federal agenda for trauma system development. Two trauma centers were simultaneously formed in Chicago and San Francisco.

The Maryland Institute of Emergency Medicine became the first completely organized, statewide, regionalized system in 1973. Similar initiatives were taken in 1971 in Illinois,10 where the designation of trauma centers was established by state law, and in Virginia in 1981, where a statewide trauma system based on volunteer participation and compliance with national standards as defined by the ACSCOT was established.

In 1973, the Emergency Medical Services Systems Act became law, providing guidelines and financial assistance for the development of regional EMS systems. In addition, state and local efforts were initiated by using prehospital care systems to deliver patients to major hospitals where appropriate care could be provided. Prehospital provider programs were formalized, and training programs were established for paramedics and emergency medical technicians (EMTs).

At that time, major teaching hospitals in large cities were, by default, recognized as regional trauma centers. With strong academic leadership, these centers were able to develop regionalization of systems of trauma care by setting examples.

ACSCOT developed a task force to publish Optimal Hospital Resources for the Care of the Seriously Injured in 1976, establishing a standard for evaluation of care. This document was the first to set out specific criteria for the categorization of hospitals as trauma centers. This document is periodically revised and is recognized nationally and internationally as the standard for hospitals aspiring to be trauma centers. The current version entitled Resources for Optimal Care of the Injured Patient was published in 2006.4 It establishes criteria for prehospital and trauma care personnel and the importance of ongoing quality assessment. In addition, ACSCOT developed the Advanced Trauma Life Support (ATLS) course in 1980, which has contributed to the uniformity of initial care and the development of a common language for all care providers.

In 1985, the National Research Council and the Institute of Medicine published Injury in America: A Continuing Health Care Problem. This document concluded that despite considerable funding used to develop trauma systems, little progress had been made toward reducing the burden of injury.11 This document also reinforced the necessity of investments in epidemiological research and injury prevention. Following the publication of this document, the Centers for Disease Control and Prevention (CDC) was chosen as the site for an injury research center, to coordinate efforts at the national level in injury control, injury prevention, and all other aspects of trauma care.

In 1987, the ACSCOT instituted the Verification/Consultation Program, which provided further resources and incentive for trauma system development and trauma centers’ designation. More recently, the ACSCOT published a document entitled Consultation for Trauma Systems with the objective of providing guidelines for trauma system evaluation and enhancement.12 In 1987, the American College of Emergency Physicians (ACEP) published Guidelines for Trauma Care Systems.13 This document focused on the continuum of trauma care, and identified essential criteria for trauma care systems.

In 1988, the National Highway Safety Administration (NTHSA) established the Statewide EMS Technical Assessment Program and the Development of Trauma Systems Course, both important tools to assess the effectiveness of trauma system components as well as for system development. NHTSA also developed standards for quality EMS, including trauma care. The standard required that the trauma care system be fully integrated into the state’s EMS system and have specific legislation (Table 4-1). The trauma care component must include designated trauma centers, transfer and triage guidelines, trauma registries, and initiatives in public education and injury prevention.

TABLE 4-1 Criteria for Statewide Trauma Care System


In 1990, the Trauma Systems Planning and Development Act created the Division of Trauma and EMS (DTEMS) within the Health Resources and Services Administration (HRSA) to improve EMS and trauma care. Unfortunately, the program was not funded between 1995 and 2000 in many states that were in the process of developing trauma systems. Two initiatives from this legislation were noteworthy: (1) planning grants for statewide trauma system development were provided to states on a competitive basis and (2) the Model Trauma Care System Plan was published as a consensus document.15 The Model Trauma Care System Plan established an apolitical framework for measuring progress in trauma system development and set the standard for the promulgation of systems of trauma care. The program was again funded in fiscal year 2001 but lost funding in 2006. New legislation is being written to further this effort. The newest document for trauma system planning uses the public health care model of assessment, policy development, and evaluation of the outcome. With appropriate federal funding, this approach will be very successful.7


The criteria for a statewide EMS and trauma systems have been determined and are identified in Tables 4-1 and 4-2. The first step is to establish legal authority for the development of a system. This usually requires legislation at a state or local level that provides public agency authority. The next step in the development of a trauma system is to determine the need of such a system. In general, this has been done in communities by reviewing the outcome of trauma cases in the region. Traditionally, such reviews have focused on preventable deaths. The surgeon’s role is critical in both leadership and commitment to establish a better standard of care.

TABLE 4-2 Emergency Medical Service System Components


The designated agency in combination with local trauma surgeons and other medical personnel develops criteria for the trauma system, determines which facilities will be designated trauma centers, and establishes a trauma registry, a fundamental component of a quality assurance program4,1417 (Fig. 4-1).


FIGURE 4-1 Regional trauma system development must progress in a sequential fashion; a comprehensive needs assessment is a pivotal early step. (Reproduced with permission from Moore EE. Trauma systems, trauma centers, and trauma surgeons: opportunity in managed competition. J Trauma. 1995;39:1.)


The most significant improvement in the care of injured patients in the United States has occurred through the development of trauma systems. However, recent data show that only 60% of states in the United States have statewide trauma systems, and about 20% have no trauma system at all. The necessary elements of a trauma system are: access to care, prehospital care, hospital care, and rehabilitation, in addition to prevention, disaster medical planning, patient education, research, and rational financial planning. Prehospital communications, transport system, trained personnel, and qualified trauma care personnel for all phases of care are of utmost importance for a system’s success (Fig. 4-1).

External peer review generally is used to verify specific hospital’s capabilities and its ability to deliver the appropriate level of care. The verification process can be accomplished through the ACSCOT or by inviting experts in the field of trauma as outside reviewers. Finally, quality assessment and quality improvement is a vital component of the system, as it provides directions for improvement as well as constant evaluation of the system’s performance and needs.

The Model Trauma Care System Plan introduced the concept of the “inclusive system”15 (Fig. 4-2). Based on this model, trauma centers were identified by their ability to provide definitive care to the most critically injured. Approximately 15% of all trauma patients will benefit from the resources of a Level I or II trauma center. Therefore, it is appropriately expected in an inclusive system to encourage participation and to enhance capabilities of the smaller hospitals.


FIGURE 4-2 Diagram showing the growth of the trauma care system to become inclusive. Note that the number of injured patients is inversely proportional to the severity of their injuries.

Surgical leadership is of fundamental importance in the development of trauma systems. Trauma systems cannot develop without the commitment of the surgeons of a hospital or community.


Death following trauma occurs in a trimodel distribution. Effective trauma programs must also focus on injury prevention, since more than half of the deaths occur within minutes of injury, and will never be addressed by acute care.

Because trauma is not considered an important public health problem by the general population, efforts to increase awareness of the public as well as to instruct the public about how the system operates and how to access the system are important and mandatory. A recent Harris Poll conducted by the Anemia Trauma Society showed that most citizens value the importance of a trauma system with the same importance as fire and police services. Trauma system must also focus on injury prevention based on data relevant to injuries and what interventions will likely reduce their occurrence. Identification of risk factors and high-risk groups, development of strategies to alter personal behavior through education or legislation, and other preventive measures have the greatest impact on trauma in the community, and, over time, will have the greatest effect on nonfatalities.1820


Because the system cannot function optimally without qualified personnel, a quality system provides quality education to its providers. This includes all personnel along the trauma care continuum: physicians, nurses, EMTs, and others who impact the patient and/or the patient’s family.


Trauma care prior to hospital arrival has a direct effect on survival. The system must ensure prompt access and dispatch of qualified personnel, appropriate care at the scene, and safe and rapid transport of the patient to the closest, most appropriate facility.

The primary focus is on education of paramedical personnel to provide initial resuscitation, triage, and treatment of trauma patients. Effective prehospital care requires coordination between various public safety agencies and hospitals to maximize efficiency, minimize duplication of services, and provide care at a reasonable cost.


A reliable communications system is essential for providing optimal trauma care. Although many urban centers have used modern electronic technology to establish emergency systems, most rural communities have not. A communications system must include universal access to emergency telephone numbers (e.g., 911), trained dispatch personnel who can efficiently match EMS expertise with the patient’s needs, and the capability of EMS personnel at the trauma incident to communicate with prehospital dispatch, the trauma hospital, and other units.

Access also requires that all users know how to enter the system. This can be achieved through public safety and information and school educational programs designed to educate health care providers and the public about emergency medical access.


Medical direction provides the operational matrix for care provided in the field. It grants freedom of action and limitations to EMTs who must rescue injured patients. The medical director is responsible for the design and implementation of field treatment guidelines, their timely revision, and their quality control. Medical direction can be “off-line” in the form of protocols for training, triage, treatment, transport, and technical skill operations or “online,” given directly to the field provider.


The word triage derives from the French word meaning “to sort.” When applied in a medical context, triage involves the initial evaluation of a casualty and the determination of the priority and level of medical care necessary for the victim. The purpose of triage is to be selective, so that limited medical resources are allocated to patients who will receive the most benefit. Proper triage should ensure that the seriously injured patient be taken to a facility capable of treating these types of injuries—a trauma center. Patients with lesser severity of injuries may be transported to other appropriate medical facilities for care.

Each medical facility has its own unique set of medical resources. As such, triage principles may vary from one locale to another depending on the resource availability. Likewise, established triage principles may be modified to handle multiple casualty incident or mass casualties. Then, a different set of triage criteria may be employed that will attempt to provide medical care to the greatest number of patients. In this scenario, some critically injured patients may not receive definitive care as this may consume an “unfair share” of resources. The goal of triage and acute medical care is to provide the greatest good to the greatest numbers.

From a historical perspective, war has been the catalyst for developing and refining the concept of medical triage. Dominique Jean Larrey, Napoleon’s chief surgeon, was one of the first to prioritize the needs of the wounded on a mass scale. He believed “… it is necessary to always begin with the most dangerously injured, without regard to rank or distinction.” He evacuated both friend and foe on the battlefield and rendered medical care to both. He refined his techniques for evacuation and determining medical priorities for injured patients over the 18 years and 60 battles while being a member of the French army.

During World War I, the English developed the “casualty clearing station,” where the injured were separated based on the extent of their injuries. Those with relatively minor injuries received first aid, while those with more serious injuries underwent initial resuscitative measures prior to definitive care. As medical and surgical care of battlefield injuries expanded, a system of triage and tiered levels (echelons) of medical care was designed. Echelons of medical care and triage of single, multiple, and mass casualties remain the paradigm for military combat medical care.

There are five echelons (or levels) of care in the present military medicine. The first line of medical care is that which is provided by fellow soldiers. Principles of airway management, cessation of bleeding, and basic support are offered by fellow soldiers. Organized medical care begins with a medic or corpsman who participates in echelon 1 care. They are assigned to functional military units and serve as the initial medical evaluation and care of the injured patient. Echelon 2 is a battalion aid station or a surgical company. Resuscitation and basic lifesaving surgical procedures may be performed at these stations. Echelon 3 is a Mobile Army Surgical Hospital (MASH) or Fleet Surgical Hospital. Advanced surgical and medical diagnostic and therapeutic capabilities are available at these facilities. An Echelon 4 facility is larger and has enhanced medical capacity. Examples include a hospital ship (USNS Mercy or Comfort) or an out-of-country medical facility (Landstuhl Region Medical Center [Army], Germany). An Echelon 5 facility is a large tertiary and rehabilitative medical facility and is located within the home country (Naval Medical Center San Diego). Each increasing echelon has a more comprehensive medical and surgical capacity. As patients are identified on the battlefield, they are triaged and transferred to the next higher echelon for care. During the Vietnam War, air medical transport enabled the triage of a seriously injured soldier from the battlefield directly to an MASH unit. The time to definitive surgical care was less than 2 hours compared to 6 hours during World War II.

The lessons learned from the triage and treatment of combat casualties were slow to translate into civilian use. Injured patients, regardless of the severity of injury, were simply taken to the nearest hospital for treatment. Neither a triage system nor an organized approach to injury existed. The ATLS course was created in the late 1970s and with it the concept of requisite skills and facilities to treat injured patients emerged.


The purpose of triage is to match the patient with the optimal resources necessary to adequately and efficiently manage his or her injuries. It is a dynamic process of patient evaluation and reevaluation until the patient receives definitive care. The challenge of a triage system lies in correctly identifying which patient has injuries in need of a designated trauma center. Studies have demonstrated better outcomes in major trauma victims who have been treated at hospitals that have a commitment for this specialized care.16 Of all trauma patients, only 7–15% have injuries that require the facilities of a dedicated trauma center.

The ideal triage system would direct patients with serious injuries to the most appropriately staffed hospital while transporting those with less serious injuries to all other hospitals within the geographic area. Due to the complexities of patient evaluation and injury determination, “the perfect triage system” is yet to be developed.

The primary goal of an effective triage system is to identify which casualties are seriously injured and in need of immediate surgical or medical care. This requires a rapid evaluation of the patient and a decision about the level of emergency care that will be needed for the patient. Once this is determined, they are matched and transported to the appropriate medical facility. The triage physician often has limited resources, information, and time to make this important decision. While many triage methods can be used, they often rely on physiologic, anatomic, and mechanism of injury information to assist in the triage decision. Once the patient has been routed to a treatment facility, information concerning the patient’s injuries and physiologic state should be transmitted to the receiving facility if possible. This will give the receiving physician an opportunity to gather the appropriate personnel and equipment to treat the incoming casualty. A concise prehospital radio report will enable the receiving medical personnel to anticipate emergent equipment and personnel needs. In some instances, a direct operative resuscitation may be indicated to stabilize the patient.21 In other cases, emergent airway control may be the primary concern. The few minutes of preparation, prior to the patient’s arrival, may be the difference in patient survival.

The other goal is to define the “major trauma victim.” While this term may be easy to conceptualize, it is very difficult to quantify. A precise definition is important so that triage, treatment, and outcomes can be compared. Prompt recognition of those patients who are in immediate risk of life (e.g., loss of airway or hemorrhagic shock) or loss of a limb (ischemia) or will need immediate operative or lifesaving interventions is paramount. These patients are in need of definitive care in an expedient fashion where delays in care may result in excess morbidity or mortality.

The Injury Severity Score (ISS) provides the means for a trauma system to retrospectively identify major trauma victims with an ISS of greater than 15 being a commonly accepted level.22 Another definition of major trauma is provided by the Major Trauma Outcome Study (MTOS), which defines the trauma patient as all patients who died due to their injuries or were admitted to the hospital.23 The threshold that defines the major trauma victim within a trauma system is based not only on the resources of a particular trauma center but also on the inability of the nondesignated hospitals to consistently provide appropriate care for an injury exceeding the threshold. This may vary from system to system.

After a traumatic event, the effectiveness of a triage system should be analyzed based on expected performance standards. Data monitoring and quality assessment tools should be applied after a disaster or after any one patient who has been treated so that system or operator errors can be identified and corrected. Each multiple casualty event presents unique problems to a triage system. Constant reevaluation and refinement are cornerstones for improved performance.

One of the accepted performance markers to an effective triage system is found in the determination of the undertriage and overtriage rates. Undertriage is defined as a triage decision that classifies a patient as not needing a higher level of care (e.g., trauma center), when in fact they do. This is false-negative triage classification.44 Undertriage is a medical problem that may result in an adverse patient outcome. The receiving medical facility may not be adequate to diagnose and treat the trauma victim.

Defining an acceptable level of undertriage is dependent on how one defines the patient requiring trauma center care. One method is to identify all the potentially preventable causes. Using this method, a target undertriage rate would be 1% or less. Using a broader definition, undertriage would also result in patients being sent to institutions without the capability to render appropriate care. In this instance, an undertriage rate of 5–10% is accepted.

Another method is to determine how many major trauma patients were incorrectly transported to a nontrauma center. If an ISS of greater than 16 or more is used to define the major trauma patient, undertriaged patients would be those patients (ISS >16) who were taken to a nontrauma center hospital. Using this method, an acceptable undertriage rate can be as high as 5%.

Overtriage is a decision that incorrectly classifies a patient as needing a trauma center, although retrospective analysis suggests that such care was not justified. It has been said to result in overutilization of finite material, that is, financial and human resources.24


Trauma triage decisions are usually made within a limited time frame and are based on information that can be difficult to obtain. These decisions are based on evidence gathered in the field that estimates the potential for severe injury. Physiologic and anatomic criteria, mechanism of injury, and comorbid factors are used in the triage decision-making process. Unfortunately, all these criteria have limitations that affect their validity in certain situations. The judgment of experienced EMS personnel is also a key factor in triage.


Physiologic data are felt to represent a snapshot into the well-being of an injured patient. Physiologic criteria include measurements of basic life-sustaining functions such as heart rate, blood pressure, respiratory rate and effort, level of consciousness, and temperature. The advantage of physiologic data is that they are readily assessable in the field with a simple physical examination. These data can be ranked into a numerical format, which allows them to be quantified, and used in various trauma scoring systems such as the Revised Trauma Score (RTS). The larger the deviation from normal, the more likely there is a severe injury. In this way, physiologic data may correlate to severity of injury and may predict serious injury or death. Patients who have sustained a mortal injury tend to have the greatest deviation in their vital signs.25 The problem is that their ability to detect physiologic derangement is time dependent. A single set of physiologic signs is only a snapshot to the patient’s state. Patients who have sustained significant injury may not manifest physiologic changes immediately after the event and, as a result, are at risk for undertriage. A significant injury may take some time to manifest life-threatening hemorrhage or tension pneumothorax. This is especially true of young, otherwise healthy adults who have significant physiologic compensation mechanisms that may mask the true extent of the injury.


The anatomic location and external appearance of the injury aid in the immediate field triage decisions. This visual picture of the injured patient may be sufficient for an experienced triage officer to make a disposition decision without further evaluation. In a mass casualty event, rapid triage may be performed with a quick visual exam of the patient. Anatomic criteria that suggest triage to a trauma center may include, but are not limited to: penetrating injury to the head, neck, torso, or proximal extremity; two or more proximal long-bone fractures; pelvic fracture; flail chest; amputation proximal to the wrist or ankle; limb paralysis; or greater than 10% total body surface area burn or inhalation injury. Each regionalized trauma system must decide what constitutes significant anatomic injury as a triage criterion.

Anatomic injury may be challenging to predict reliably based on physical examination in the field. Fracture of long bones, amputations, and skin and soft tissue injuries may appear devastating in the field but are rarely life threatening and may distract the field examiner as well as the patient from more subtle and serious injuries.

Significant blunt chest and abdominal injuries can have little external evidence of internal injury and initial physical examination lacks diagnostic accuracy.26,27 Other significant injuries missed on initial examination include spine28and certain types of pelvic injuries. A pelvic bony injury can be diagnosed on physical examination in the awake, cooperative patient; however, a significant number of trauma victims have altered mental status due to head injury or ingestion of drugs or alcohol.

The distinction between blunt and penetrating injury is an important triage distinction. Oftentimes there may be little external trauma to the patient. However, recognition of the penetrating wounds correlated with the likelihood of internal injury is needed to effectively triage these patients. Penetrating injuries to trunk and proximal extremities are of concern because of their proximity to vital structures; however, it is nearly impossible to know the direction or depth of penetration while in the field. Finally, the triage officer must expeditiously evaluate patients and not perform time-consuming physical examinations in the field that only slow down the triage process. Complex patients may be better served by urgent transport to a trauma center.


Evaluation is more than the simple determination of how a trauma injury occurred. To the trained eye, it can give information on the type, amount, and direction of force or energy applied to the body. Prehospital personnel, who view the effects of the forces that were applied during the injurious event, can estimate the amount of energy involved. This, in turn, helps predict the likelihood of injury. Mechanisms of injury felt to have a high potential for major trauma include falls of more than 15 ft; motor vehicle accidents with a fatality at the scene, passenger ejection, prolonged extrication (>20 minutes), or major intrusion of the passenger compartment; pedestrians struck by a motor vehicle; motorcycle accidents of more than 20 mph; or any penetrating injuries to the head, neck, torso, or proximal extremities. When used as a triage criterion by itself, mechanism of injury results in the high overtriage rate. However, when combined with other triage components, such as physiologic indices and anatomic injury, mechanism of injury improves the sensitivity and specificity of the triage process.29,30


Age has been shown to impact the outcome of trauma victims and should be taken into consideration when triaging a patient. Elderly trauma victims, using a variety of definitions (i.e., >55 years old, >65 years old, etc.), have been shown to have increased morbidity and mortality compared to younger trauma victims. When compared to young patients, the elderly are at risk for undertriage, because a similar amount of force may cause a greater magnitude of injury.31

The effect of age on morbidity and mortality is not as clear in the pediatric population.32 There are significant differences in physiology and anatomy in the pediatric population that require specialized equipment, facilities, and personnel. Certainly, the optimal treatment involves identifying the unique resources needed to care for the injured child and having those available when needed. These differences are significant enough that specialized triage criteria have been developed for the pediatric population.33

Chronic diseases have also been shown to have a significant impact on morbidity and mortality in the trauma victim independent of age and injury severity.34 Acute conditions such as ethanol or cocaine intoxication or systemic anticoagulation may also impact morbidity and mortality. Comorbidities such as cardiopulmonary, hepatic, renal disease, diabetes mellitus, malignancy, or neurologic disorders have been found to have increased mortality rates compared to their disease-free counterparts. The problem is that many times the associated medical condition of the patient cannot be ascertained in the prehospital arena unless the patient has identification such as a medical alert bracelet or a relative who can provide the necessary history to the field personnel.

Environmental extremes can have serious consequences for the trauma patient. Hypothermia is known to have adverse physiologic effects, prolongs blood coagulation time, and contributes to mortality.35Prolonged heat exposure may lead to dehydration. Burn injuries require accurate assessment for resuscitation and wound care, as well as evaluation for potential inhalation injury. When combined with associated trauma, patient management can be complex36 (Table 4-3).

TABLE 4-3 Commonly Used Trauma Triage Criteria





A working familiarity of clear, concise, and reliable triage guidelines is essential for effective triage. Experience and judgment of EMS personnel are crucial to this mission. EMS personnel are in a unique position to directly assess the trauma scene, ascertain the mechanism of injury, determine the extent of the patient’s injuries, and estimate the patient’s physiologic response. For example, a patient with a fractured femur due to a frontal, high-speed motor vehicle collision will be evaluated and triaged differently than will a patient with a femur fracture due to a low-speed collision. Paramedic triage is outlined in the prehospital trauma life support manual.

Several studies have shown that prehospital field personnel judgment can be as good or better than the available triage scoring methods commonly in use37 and, when combined with other triage criteria, improves on the identification of major trauma victims. In a systematic review of Mulholland et al. there was no conclusive evidence for or against paramedic judgment in the field.38 The one constant theme in triage at all levels of medical personnel was the level of clinical experience. Pointer et al.39 studied the compliance of paramedics to established triage rules. Paramedic triage was best when evaluating triaging based on a patient’s injury patterns. Compliance was intermediate when based on mechanism of injury and the lowest for patients evaluated for physiologic triage criteria. They demonstrated a paramedic undertriage rate of 9.6%, which is relatively close to the acceptable 5% or less undertriage rate.


In order for a triage scoring method to be acceptable for use in the field, it must meet certain criteria. The components of the scoring scheme must be credible, meaning that they have some correlating relationship with the injuries being described. Because there is no “gold standard” to test the accuracy of the scoring scheme, the results of the scoring scheme must be in general agreement with other, currently accepted scoring methods.40

The triage scoring method must correlate with outcome. The scores that indicate more severe injury should identify the patients with worse outcomes. 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. 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.


Image Trauma Index

The Trauma Index was one of the earliest triage scoring methods, first reported in 1971 by Kirkpatrick and Youmans.41 It included measures of five variables: blood pressure, respiratory status, central nervous system (CNS) status, anatomic region, and type of injury. One study showed some correlation with injury severity42; however, the Trauma Index never saw widespread use. A revision of the Trauma Index in 1990 reported undertriage and overtriage rates comparable to those of the Trauma Score (TS); circulation, respiration, abdominal/thoracic, motor, and speech (CRAMS); Prehospital Index (PHI); and mechanism of injury scales and correlated to the final ISS.43

Image Glasgow Coma Scale

When Teasdale and Jennett first introduced the Glasgow Coma Scale (GCS),44 it was intended as a description of the functional status of the CNS, regardless of the type of insult to the brain, and was never intended to be used as a prehospital assessment tool. The three components of the score reflect different levels of brain function with eye opening corresponding to the brainstem, motor response corresponding to CNS function, and verbal response corresponding to CNS integration.

Because the degree of injury to the CNS is considered to be a major determinant of outcome in trauma victims, many of the field triage tools measure CNS function, including the TS,45 the RTS,46 the CRAMS scale,47 and the Trauma Triage Rule (TTR).48 Interpretation of GCS in the presence of an intubated patient diminishes the ability to use the GCS as a prehospital evaluation tool. A more recent study found that the motor component of the GCS is almost as good as the TS and better than the ISS in predicting mortality. This suggests that the motor component score could be used to identify patients who are likely to require urgent trauma center care.

Image Triage Index, Trauma Score, Revised Trauma Score

The Triage Index (TI) was described in 1981, and analyzed physiologic parameters of an injured patient. These variables were examined alone and in combination in an effort to make the TI more precise. One year later, Champion et al. modified the TI by adding systolic blood pressure and respiratory effort in an effort to be more discriminatory in patient severity identification. The resulting TS was designed to look at those physiologic parameters known to be associated with higher severity of injury if found to be abnormal.45 Central to this idea was the fact that the known leading causes of traumatic death were related to dysfunction of the cardiovascular, respiratory, and CNS. The authors recommended trauma center care for trauma victims with a TS of 12 or less. The TS was revised in 1989 because of concerns about accurate assessment of capillary refill and respiratory effort at night as well as potential underestimation of CNS injury.46 These components were deleted and the RTS consists of three parameters: GCS, systolic blood pressure, and respiratory rate.

Image CRAMS Scale

CRAMS was first proposed as a simplified method of field triage.47 These parameters are individually assessed and assigned a value corresponding to normal, mildly abnormal, or markedly abnormal. With a range of 0–10, a score of 8 or less signifies major trauma, indicating that the patient should be taken to a designated trauma center. Both retrospective and prospective studies have shown that the CRAMS method of triage is accurate in identifying major trauma victims with relatively high specificity and sensitivity and is easy to use.49

Image Prehospital Index

The PHI consists of field measurements of blood pressure, pulse, respiratory status, and level of consciousness, which were determined to have the best correlation with mortality or the need for surgery. A subsequent prospective multicenter validation study by the same authors showed that the PHI is accurate in predicting the need for lifesaving surgery within 4 hours and death within 72 hours following injury.50 Furthermore, the attachment of non-time-dependent variables such as age, body region injured, and mechanism of injury to the PHI improved the predictive power to select those patients who were likely to need intensive care or a surgical procedure.

Image Trauma Triage Rule

The TTR proposed by Baxt et al. consists of measurements of blood pressure, the GCS motor response, and the anatomic region and type of injury.48 Rather than comparing the scoring method to traditional outcome measures to determine the factors that constitute a major trauma victim, major trauma was defined a priori as a systolic blood pressure of less than 85 mm Hg; a GCS motor component score of 5 or less; or penetrating trauma to the head, neck, or trunk. Retrospective review revealed major trauma victim identification with a sensitivity and specificity of 92%. The TTR was concluded to potentially reduce overtriage while maintaining an acceptable undertriage rate. However, it has not been adapted widely.

Image Disaster Triage: Simple Triage and Rapid Treatment (START)

In the event of a mass casualty or disaster, EMS personnel may utilize the 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.51 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: (a) green—minor injuries (walking wounded); (b) red—immediate; (c) yellow—delayed; and (d) 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 >30, the patient is an immediate transport. If the respiratory rate is <30, perfusion is assessed. A capillary refill of >2 seconds will mandate an immediate transport. If the capillary refill is <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. The Fire Department of New York used this system during the World Trade Center disaster. Unfortunately, due to the collapse of the buildings and concern for the safety of the rescue workers, the START system came to a complete halt.52 It resumed only when it was declared safe to approach ground zero.

In some systems the START system is coupled with severity scores: in the immediate category the TS varies from 3 to 10, in the urgent category the TS varies from 10 to 11, and in the delayed (nonurgent) group the TS is 12.

The triage principles are the same for children and adults. However, due to differences in physiology, response to insults, ability to talk and walk, and anatomic differences, disaster triage in the pediatric age group is not straightforward. Assessment tools have been proposed to increase the accuracy of the process but were found to have major limitations.

The START system is important in the triage of severely injured trauma patients because those requiring surgical care are transported by air or ground ambulances to trauma centers distant enough from the incident where the number of victims is lower and the resources are still available to provide optimal care.

Image Combination Methods

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.

Image American College of Surgeons Field Triage System

The ACS Field Triage System is a more complete, advanced triage scoring scheme that is described in the Resources for Optimal Care of the Injured Patient. This decision scheme describes indications for transport of the trauma victim to a trauma center based on specific physiologic and anatomy of injury variables. In addition, mechanism of injury and comorbid factors are evaluated and, if specific criteria are met, may also indicate transport to a trauma center. Finally, if there is concern on the part of the prehospital medical personnel that the victim may have significant injuries, consideration is given to taking the patient to the designated trauma center. Fig. 4-3 shows the triage decision scheme that is widely used throughout the country.


FIGURE 4-3 Prehospital triage decision scheme recommended by the American College of Surgeons Committee on Trauma. (Reproduced with permission from The American College of Surgeons Committee on Trauma. Resources for Optimal Care of the Injured Patient: 2006. Chicago, IL: American College of Surgeons; 2006.)


Triage principles may need to be modified to include triage of multiple patient and mass casualty situations.

Image Single Patient

Triaging a single trauma victim is relatively straightforward. The prehospital care provider assesses the patient according to the defined triage criteria for that particular regionalized trauma system. If the patient meets the criteria of a major trauma victim, he or she is transported to the nearest designated trauma center.

Image Multiple Casualties

In the situation of multiple patients, such as seen with multiple cars involved in the same accident, the same essential principles apply; however, decisions must be made in the field as to which patients have priority. A state of multiple casualties occurs when the numbers of patients and injury severity do not exceed the hospital resources. Those 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. This type of situation can stress local resources, and possible diversion of the less critically injured to another trauma center should be considered. Monitoring transports with online computer assistance allows for contemporaneous determination if one trauma center is overwhelmed.

Image Mass Casualties

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.53

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.54 In some disaster scenarios moving the intensive care 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 periodically have 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.55

Image Disaster Management

Events surrounding the recent terrorist attacks of the Oklahoma Federal Building, World Trade Center, and the Pentagon, and natural disasters such as Katrina, should crystallize the resolve of all medical personnel to become educated and proficient in disaster management. The approach to disasters, whether natural or man-made, requires a coordinated relief effort of EMS, hospital, fire, police, and public works personnel. This multiorganizational operation can function in a crisis environment only if it is well directed and controlled. The ability to assess a disaster scene, call in appropriate personnel to provide damage control, fire and rescue operations, and crowd control is dependent on an organization structure that permits dynamic information processing and decision making of 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 works to command and control all of resources at the disaster site. Dynamic disaster scene information is processed at the incident command and decisions as to how best to engage the 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 will often set up a triage area in front of the emergency department to handle these patients. Present-day medical teaching supports the treatment of any patient who arrives at an institution’s doorstep. Perhaps thought should be given to transporting groups of these patients to secondary medical facilities so that the closer hospitals do not become overburdened with an influx of patients. The use of outpatient operating facilities is being considered 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 an intrafacility fire or explosion and may remain only a local or regional problem. As was seen at the World Trade Center, the magnitude of a local disaster was of such proportions that a national response was needed to address the rescue and recovery efforts. The standard appeal for this today is to activate the National Disaster Medical System.

Interestingly, in some of the more recent natural disasters, there have been approximately 10–15% of the survivors who were seriously injured. The remaining people either were dead or had mild to moderate trauma. It becomes a pivotal task to rapidly sort through the survivors and identify the level of care needed by each patient. In the World Trade Center, 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.52Following the collapse, 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 3,000 fatalities, which included civilians and rescue personnel.

The experience in Israel 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.

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 ever 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.5659

In mass casualties, hospitals become overwhelmed very easily. Therefore, communication between hospitals is critical to distribute the casualties in an evenly fashion.

Surgeons should be familiar with the basic principles of mass casualty management. Trauma surgeons should be the leaders in this field, as trauma systems serve as a template for the triage, evacuation, and treatment of mass casualty victims. The American College of Surgeons has emphasized on this critical role for surgeons.60


There is little argument that a regionalized trauma system reduces the number of potentially preventable deaths due to trauma.16,61 To do so, one must accurately select which trauma victim will benefit from the resources of a trauma center. The dilemma is 2-fold: (1) Which criteria should be used to define the “major trauma” victims? (2) How are these patients identified in the field? Other relevant questions include: Does selective triage of patients in terms of hospital resources at the time of hospital admission benefit the major trauma patient, and, if so, what selection criteria are the most appropriate? Do transport times modify the definition of a major trauma victim, and does this influence outcome? Finally, do present field triage criteria provide adequate rates of undertriage and overtriage? Each of these questions will be addressed individually.

Image Major Trauma Patient

The definition of a major trauma patient is a person who has sustained potentially life- or limb-threatening injuries and is based on retrospective analysis of the patient’s injuries. The major trauma definition is used primarily to monitor field triage criteria as well as calculate undertriage and overtriage rates within a regional trauma system. Unfortunately, there is no absolute standard for the criteria that have been used when defining major trauma. The best that can be accomplished is to retrospectively compare quantified injury severity data to mortality and then use a predefined threshold as defining major trauma.

The ISS is a measure of physical injury, based on adding up the square of the three highest individual anatomic injury scores (Abbreviated Injury Scale [AIS], range 1–6) calculated from all of the patient’s known injuries.22 When used to define major trauma, an ISS of 15 or more has been the most frequently utilized threshold. Using this definition, a trauma victim must have a single anatomic injury score of 4 or two AIS 3 injuries in order to be categorized as sustaining “major trauma.” Because ISS has been shown to have a good correlation with mortality over a wide range of ages and different types of injuries, it has been the most frequently utilized method for stratifying the injuries of patients for comparison with prehospital triage scores. However, it has several shortcomings when used as a determinant of major trauma with regard to analysis of field triage criteria.

Several studies have shown that preventable deaths can occur with a single AIS 3 injury.14,62 For example, a patient with a closed head injury and an AIS of 3 is at a higher risk of death than if the patient had a similar grade extremity injury. In a retrospective autopsy analysis of all patients dying within 24 hours, Bansal et al. demonstrated that closed head injury was the most common cause of death; however, there was a significant variation in ISS and therefore ISS alone could not be used as a predictor of early death.63 As a result, there is no consensus on the numeric value of ISS that defines major trauma. Stewart et al. used an ISS of greater than 12 to define their study population when they reported on the improvement in outcomes of motor vehicle accident victims after trauma center designation.64 Similarly, Petrie et al. also used an ISS of greater than 12 when they reported on the improvement of outcomes of patients who had trauma team activation when compared to those who did not.65 However, Morris et al. defined major trauma as a patient with an ISS of 20 or more when they reported on the ability of the TS to prospectively identify patients with life-threatening injuries.66 Additionally, Norwood and Myers stratified their patient sample into two groups based on ISSs of 19 or less and 20 or more—when they reported on outcomes from a rural-based trauma center.67 Thus, comparing studies that define major trauma becomes very difficult due to the differences in the ISS threshold.

A second problem with ISS is that it is based on injuries identified within specific anatomic regions and takes into account only one injury per body region. Therefore, ISS may not be a sensitive indicator of certain types of injuries. Several studies have found that ISS is not as accurate in identifying the severity of the injury in penetrating or blunt trauma, in which several organ systems may be injured within the same anatomic location. This has led to the development of specialized anatomic injury scoring systems such as the Penetrating Abdominal Trauma Index (PATI)68 and, ultimately, the Organ Injury Scale (OIS)69 that may more accurately reflect the severity of the injury. A modification to the calculation of ISS scoring has been introduced as the New Injury Severity Score (NISS), which is defined as the sum of the squares of the AIS scores of each of a patient’s three most severe AIS injuries regardless of the body region in which they occur. This method has been found to be more predictive of survival, but may overestimate the severity of injury for lesser injury grades.70 In addition, injury severity scoring may also be inaccurate, as the ISS fails to differentiate between severity of injury and mismanagement of injury and, as a result, assigns an increased injury severity to lesser injuries of inappropriately managed patients.

Transport times may need to be included in the definition of the major trauma patient when used for triage or interfacility transport purposes, particularly when they exceed 30 minutes. When time is added to lesser injuries before definitive care, ongoing bleeding, the magnitude of the resuscitation, and the relative stability of the patient may increase the injury severity of otherwise equivalent injuries. A number of studies have shown that hemodynamic and respiratory dysfunction, as well as mortality, is increased with increasing transport times.71 As such, when long transport times are a problem and complications due to long transport and inadequate resuscitation can be anticipated, these patients should be considered for a higher level of care where critical care resources are more likely to be available. Patient transport modalities and point to trauma center time of transport are unique to each region. Goldstein et al. validated a transport decision process that utilized a modification of the PHI (the pretransport index) and documented the time and distance from a trauma center for these trauma transfer patients in British Columbia. The pretransport index adds onto the two PHI variables: intubation and pneumothorax. Accurate recognition of the more seriously injured patients and the knowledge of the quickest modality to transport the patient to a trauma center resulted in a quicker time to definitive time to care.72 Recently, an analysis by the Resuscitation Outcomes Consortium (ROC) of the association between EMS intervals and in-hospital mortality following serious injury was conducted. A total of 3,656 patients were prospectively collected and a secondary retrospective analysis was performed studying mortality as a function of EMS transport time. All patients were seriously injured with a mean systolic blood pressure less than 90 mm Hg and a GCS less than or equal to 12. Of those studied, 22.0% died after EMS transport to the hospital and most within the same day. The overall mean EMS time was 36.3 minutes; however, when EMS time was delineated into 10-minute increments, there was no evidence of increased mortality. Similarly, total EMS times, grouped by lowest to highest quartile, did not reveal any increase in mortality. The authors concluded that even though decreased EMS transport times may improve mortality for select patients, overall this relationship across a wide field of injured victims does not seem to affect mortality. Therefore, utilization of the most appropriate transport mode for specific patients should maximally utilize health care resources and dollars.73

Image Field Triage Scores

Triage scores that are based on physiologic data are accurate in doing so. The original “first step” field trauma triage criteria were published by consensus from the ACSCOT that stratified them by GCS ≤12, SBP ≤90 mm Hg, and RR <10 or >29.74 The TS, CRAMS scale, RTS, and the PHI have good correlation with the ISS and are able to predict mortality with a sensitivity of at least 85%. However, no single field triage scoring scheme has been universally accepted as the gold standard. This is due, in part, to the fact that there is no agreed-upon standard that defines “major trauma” that allows for comparison of the individual triage scoring systems. An evidence-based analysis is limited by this problem. As a result, each of the individual scoring systems has its advocates as well as critics.

When Gormican originally described the CRAMS scale, rather than using an ISS threshold to define major trauma, he defined it as the patient who died in the emergency department or went directly to the OR.47 Minor trauma was defined as a patient who was discharged home from the emergency department. Using a CRAMS score of 8 or less to signify major trauma, he found a sensitivity of 92% and a specificity of 98% in identifying major trauma victims. Others examined the ability of the CRAMS scale to accurately identify patients who required admission to the hospital or any operation for their injuries. Using this definition for major trauma, they found that a CRAMS score of 8 or less failed to identify two out of three patients.

Champion et al., who constructed the TS by analyzing CNS, cardiovascular, and respiratory data, a priori defined major trauma as a TS of 12 or less because it correlated with a decreased probability of survival.45 It has been shown that a TS of 12 or less also failed to identify two out of three patients who required admission or an operation. Similar criticisms in the literature can be found for the PHI for its failure to accurately identify patients requiring emergency surgery, and the RTS for its low sensitivity in identifying patients requiring emergency treatment.75 The addition of the variables of age, body region injured, mechanism of injury, comorbidity, and the PHI improved prediction of the PHI alone by 10% (sensitivity of 76% vs. 66%). Unfortunately, the addition of the mechanism of injury to the PHI was almost as accurate as all of the major descriptors.

It has been shown that the physiologic-based triage scores were unable to accurately identify survivors of major injuries, each score having a sensitivity and specificity of less than 70%. Holcomb et al. recently evaluated the utility of manual vital signs plus the GCS (motor and verbal scores) to predict the need for lifesaving interventions in nonclosed head injured patients. In this group, patients with a weak radial arterial pulse had an 11-fold increase in the need for a lifesaving intervention. A GCS verbal score of 2–3 in a nonclosed head injured patient had a 6-fold increase while a GCS motor score of 2–3 had a 20-fold increase in the need for a lifesaving intervention. An additional conclusion was that the addition of automated vital sign reporting, oxygen saturation monitors, or end-tidal CO2 monitors did not improve the predictive model of which patients might need a lifesaving intervention.76 The ROC group studied mortality and hospital length of stay in 6,259 adult trauma patients meeting ACSCOT “first step” physiologic triage criteria. Patients who died or had an image days were considered high risk, whereas survivors and image days were low risk. Total patient mortality in the high-risk category was 58.0%. Those patients were found to have a statistically significant increase in abnormal respiratory rate as well as depressed GCS as sole criteria for triage. The authors further evaluated the need for advanced airway management, outside of the ACSCOT criteria, and found that 31% of high-risk patients compared to 5% of low-risk patients required advanced airway interventions. The authors conclude that no specific physiologic parameter using present ACSCOT physiologic criteria can be omitted, but perhaps airway intervention should be added to further risk stratify high-risk trauma patients.74

The incorporation of non-time-dependent data, such as mechanism of injury, anatomic injury, and comorbid factors, has been shown to make physiologic-based triage scores more sensitive in identifying the major trauma victim. However, questions have also been raised as to whether this type of data identifies the major trauma patient. Its ability to do so appears to be dependent on the context in which it is used. For example, Cooper et al. found that mechanism of injury had a positive predictive value of only 6.9% when used to identify patients with an ISS of 16 or greater. They concluded that it did not justify bypass of local hospitals when used as a sole criterion for triage to a trauma center.77

There are conflicting reports when analyzing non-time-dependent criteria as a determinant of outcome in trauma patients. Smith and colleagues stratified patients into age over 65 and age under 65, and they found that preexisting conditions did not significantly affect outcome. Age, however, was a significant determinant of mortality. DeKeyser et al. compared the mortality and functional outcomes of patients who were stratified into three groups based on age: age 35–45, age 55–64, and age 65 and over. They found that there were no differences between the three groups in terms of ISS, mortality rates, or functional outcome.78 Van der Sluis et al. also evaluated differences in mortality and long-term outcome between young and elderly patients. They analyzed two groups of patients with an ISS of 16 or greater: age 20–29 and age 60 and over. They reported that while there was a significant difference in terms of early mortality, survivors of both groups were discharged in equal percentages and their functional outcome 2 years after injury was essentially the same.79

A possible explanation for these contradictory findings may be that there are interactions between all the possible factors that have not been previously appreciated. Hill et al. analyzed multiple factors as possible determinants of outcome in major trauma patients (image). They found that preresuscitation GCS was the overall strongest predictor of mortality. However, when the patients were stratified into different GCS categories (GCS score 3, 4–12, and 13–15) and the same analysis was performed, they found that each group had a different factor that best predicted mortality. Systolic blood pressure was the strongest predictor of mortality in the GCS 3 group, ISS in the GCS 4–12 group, and age in the GCS 13–15 group.80

Finally, the use of non-time-dependent data requires that the prehospital personnel have enough training and experience to recognize, interpret, and report them to the physician. Burstein et al. reviewed the prehospital EMS reports for specific ACS mechanism of injury triage criteria and found that it was underreported in standard EMS reporting documentation. Reporting improved with the use of a structured data instrument that requested the presence or absence of the criteria.81 A paramedic’s ability to recognize and report this type of criteria may explain the discrepancy in studies reporting on the ability of paramedic judgment to correctly or incorrectly triage patients to a trauma center. The mechanism of injury does seem to have a correlation with the need for a higher intensity of medical care or operation. In a study by Santaniello et al., nearly 50% of patients who met a mechanism of injury criteria needed an operative intervention.82

Image In-Hospital Triage

Secondary, or in-hospital, triage complements field triage by stratifying the immediate needs of the trauma patient at the time of admission. The emphasis of this retriage is to direct the patient into the proper hospital area: urgent care, emergent care, trauma bay, or the OR. During a multiple casualty event, this in-hospital triage is essential to maximize hospital resource allocation and patient flow.

Tinkoff et al. reported on a two-tiered trauma response protocol.83 They used field triage criteria to identify patients requiring either a surgery-supervised “trauma code” or an emergency medicine-supervised “trauma alert.” Using this protocol, they found that accurate identification of the most seriously injured patients was achieved as demonstrated by the improved ability to predict those patients who would require direct disposition to the OR or ICU. Prehospital prediction models as well as admission systemic inflammatory response syndrome (SIRS) scores may be useful to predict the need for ICU services, and estimate length of stay and potential mortality of seriously injured patients.

Hoyt et al. originally described predefined field criteria that indicated OR resuscitation.21 Indications included cardiac arrest with one vital sign present, persistent hypotension despite field intravenous fluid, and uncontrolled external hemorrhage. They found that penetrating and blunt trauma patients who underwent operation in less than 20 minutes had a significantly greater probability of survival versus that predicted by MTOS data.

A more recent analysis of their 10-year experience with OR resuscitation shows the survival advantage predominates in the penetrating trauma victims.84 Rhodes et al. used a variety of triage criteria to indicate need for OR resuscitation: systolic blood pressure of 80 mm Hg or less, penetrating torso trauma, multiple long-bone fractures, major limb amputation, extensive soft tissue wounds, severe maxillofacial hemorrhage, and witnessed arrest.85 The mean ISS and survival rate of all patients meeting these criteria were 29.3% and 70.4%, respectively, which were better than those predicted by TRISS methodology. Finally, Barlow et al. have advocated triage of pediatric patients (age 16 and younger) directly to the OR based on mechanism of injury and have reported survival rates of 100% for patients admitted with stab wounds and 94% for patients admitted with gunshot wounds.86,87

Secondary triage has also been shown to benefit the hospital in terms of human and financial resources. DeKeyser et al. reported that the institution of a two-tiered, in-hospital trauma response system, based on patient status at the time of admission, reduced the cost of trauma care by more than $600,000 over a 1-year period by reducing the utilization of personnel, OR, laboratory work, and protective wear.88Secondary triage characteristics such as patient response to resuscitation measures, newly diagnosed major injuries, or the presence of markedly abnormal blood values (e.g., elevated lactate levels) portend the need for enhanced medical resources and ICU care.

Image Undertriage/Overtriage

The determination of the rates of undertriage and overtriage based on the use of each of the current field triage scoring methods would provide an answer to the main question of which method best identifies the major trauma patient in the field. The best method would have the lowest rates of both undertriage and overtriage. However, the variability over an equivalent definition of a major trauma patient makes this type of analysis subject to criticism.

It is impossible to achieve perfect overtriage and undertriage rates using current field triage methods. West and colleagues found that the addition of non-time-dependent criteria to traditional physiologic triage criteria reduced the undertriage rate from 21% to 4.4%, when undertriage is defined as non-CNS-related motor vehicle accident deaths occurring in non-trauma-designated hospitals. However, depending on the definition of major trauma, overtriage ranged from 36% to 80%.

Other factors also appear to confound analysis of undertriage and overtriage. Studies have found that major trauma patients (defined by ISS) were more likely to be undertriaged if they were elderly or had single-system injuries. Patients with minor injuries were more likely to be overtriaged if they were intoxicated, obese, or had an injury to the head or face. In reality, acceptable rates of undertriage and overtriage are dependent on how a trauma system defines major trauma and the type of field triage criteria employed.

The San Diego Trauma System has reported overtriage rates by comparing patients transported to those entered into the trauma registry using MTOS criteria. Data regarding preventable deaths are also available because all nontrauma centers have trauma deaths reviewed. Using this approach the data suggest that combining physiologic and non-time-dependent criteria leads to an overtriage rate of approximately 35% and an undertriage rate of less than 1%. These rates have been found to be stable over time and would seem to be reasonable targets. Looked at another way, this translates to about 30% unnecessary transports, which calculates to 2,000 patients per year or about 6 patients per day. This amounts to no more than one to two extra patient evaluations per trauma center per day, hardly a significant overburden to a trauma system.

At present, a combination of methods may provide the most accurate field assessment of the seriously injured trauma victim and represents the current state of the art in identification of major trauma victims. A number of studies have shown that the sensitivity and specificity of physiologic-based triage scoring methods are improved by the addition of anatomic and/or mechanistic injury data. The addition of the mechanism of injury with the PHI did not improve the ability to identify seriously injured trauma patients. The structure of triage decisions must be based on the individual trauma system’s unique resources and capabilities in both the prehospital and hospital phases of care and then employed such that patient morbidity and mortality are minimized.

Image Interhospital Transfer

Many trauma victims who live in rural communities do not have immediate access to a designated trauma center or regional trauma system. These patients are generally taken to the local community hospital for their initial care. While most are adequately cared for by these facilities, there are a significant number of patients who will require the services found only at a hospital dedicated to the overall care of the trauma patient. Previous studies have shown that these patients are at an increased risk of death. Some of the factors that have been implicated in contributing to potentially avoidable mortality in this situation include failure to recognize the severity of the injury, lack of adequate resuscitative measures, and delay in or lack of necessary treatment procedures for stabilization. It is imperative that the initial treating physician should be able to recognize that the trauma victim may have injuries that require diagnostic and/or therapeutic modalities beyond the scope of the initial receiving hospital. If this situation is identified, then transfer of the patient to a “higher level of care” is appropriate.

Interhospital transfers should occur from one facility to another that will provide the additional resources needed. This generally occurs from a Level III or IV hospital as part of a regionalized trauma system. Patients may also need care from specialized centers such as a burn center or a pediatric trauma center. However, one must recognize that the period of transport is one of potential instability for the patient, and the risks of transport must be balanced against the benefits of a higher level of care.

Risk to the patient can be minimized with the use of proper equipment, personnel, and planning. The patient may need to undergo a period of resuscitation and stabilization prior to transfer.89 Some patients may not stabilize and require more definitive intervention prior to transfer. Communication with the trauma center will assist in this determination as well as interventional planning. A patient with an unstable intra-abdominal hemorrhage may need a damage control surgery with abdominal packing in order to be stable enough for transfer. The trauma surgeon could be in constant communication with the outlying surgeon to assist in the decision making for the operative procedure. This concept is particularly important with distant interhospital transfers. In addition to the medical aspects of interhospital transfer, physicians must also comply with certain federal and local legal regulations. Failure to do so has serious ramifications for the transferring hospital as well as the individual physician.90

Image Criteria for Interhospital Transfer

Identification of a trauma victim who may benefit from transfer to a designated trauma center is based on specific criteria. A number of factors must be examined when making this decision, including patient status and recognition of possible injuries and/or comorbid factors as well as the personnel and equipment resources necessary for optimal patient care.

Criteria for transfer are often not followed because of financial conflicts or failure to appreciate the long-term complexities of certain injuries.91 This may be best addressed in a trauma system through a legislative process that defines which patients should be transferred to which level of care. The Colorado State Board of Health has published Rules and Regulations pertaining to the Statewide Trauma Systemin which criteria for interhospital transfer have been defined.92 Patient criteria are based primarily on physiologic and anatomic injury data (aortic tears, liver injuries requiring intraoperative packing, bilateral pulmonary contusions requiring nonconventional ventilation, etc.), and on the level of care (Level II, III, IV) that the patient’s facility is able to provide. If the patient meets the criteria for that specific health care facility, then consultation with a Level I trauma surgeon and discussion of possibility for interhospital transfer is mandatory.

Interhospital transfer may be essential in multiple casualty events whereby a single hospital is overburdened by casualties. In this case the criteria for the transfer of patients change in order to offload the primary hospital patient load. Good triage principles need to apply so that those patients who would benefit the most would be transferred. These transfers may even occur between two equivalent level institutions in order to facilitate the distribution of trauma victims. As was demonstrated in the World Trade Center disaster, the walking wounded inundated the closest medical facilities to ground zero. This condition has the potential to make it more difficult to identify and treat the most seriously injured patients from the mass of patients who arrive at the hospital.

Image Methods of Transfer

Transfer of the trauma victim must be organized in a way that minimizes the risk to the patient during the transfer process. This includes establishing transfer protocols at the EMS and institutional levels prior to transport. It also includes the planning that is necessary after the decision for transfer is made in individual cases with respect to the type of equipment, mode of transport, and personnel necessary to maximize patient safety.

Image Transfer Agreement

Minor delays can have adverse consequences for the major trauma victim; it is therefore necessary to expedite the transfer process once its need is recognized. Transfer agreements are established protocols between hospitals that ensure rapid and efficient passage of pertinent patient information prior to the actual transfer. This should include patient identification, history and physical examination findings, diagnostic and therapeutic procedures performed and their results, and the initial impression and a clear identification of the referring and receiving physicians. This information then allows the trauma surgeon at the receiving hospital to suggest possible diagnostic or therapeutic maneuvers that may be required prior to transfer, such as intubation, insertion of a nasogastric tube, Foley catheter, or thoracostomy tube. It also allows for mobilization of resources, such as an ICU bed or OR, at the receiving hospital in anticipation of possible injuries. The physicians involved should also discuss the mode of transportation, accompanying personnel, and equipment that may be needed for optimal transfer. Discussion should also include who will assume medical control of the patient during transport. Full documentation, including a summary of care from the referring hospital and copies of all studies, should accompany the patient to the receiving hospital.

Image Transport Modality

The objective is to get the trauma victim to the receiving hospital as quickly and safely as possible. However, the mode of transportation is dependent on the availability of a particular mode, distance, geography, weather, patient status, and the skills of the transport personnel and equipment that will likely be needed during transport. This should be discussed between the referring and receiving physicians with each transfer. Knowledge of transporting agencies in the area and their availability should be ascertained as soon as the need for transport is recognized.

The patient should have appropriate monitoring of physiologic indices, including invasive monitoring, during the transport period. This may include monitoring of respiratory rate, cardiac rhythm and blood pressure, intracranial pressure, and central venous or pulmonary artery pressure. If the patient is intubated, end-tidal CO2 should be monitored and the transport ventilator should have alarms to indicate disconnects and high airway pressures. The other additional equipment necessary for safe transport is that needed for effective ACLS/ATLS interventions and has been outlined in a number of publications.

Image Transport Team

The patient should be accompanied by at least two people in addition to the vehicle operator, one of whom should have requisite training in advanced airway management, intravenous therapy, cardiac dysrhythmia recognition and treatment, and ATLS. If the transporting personnel do not have the necessary training or skills, a nurse or physician should accompany the patient during transport to ensure optimal care.


Reduction in the morbidity and mortality of trauma patients who require the resources of a trauma center depends on early identification of the severely injured, proper initial stabilization, and safe interhospital transfer.93 There is evidence that patients who sustain major trauma in a rural or small community setting are at an increased risk for adverse outcomes. A high incidence of departure from well-defined standards in the initial evaluation and management of major trauma victims in rural community hospitals has been demonstrated. A report on the care of fatally injured patients in a rural state found that 22% of fatally injured patients with non-CNS injuries reaching the emergency department alive had potentially survivable injuries. Errors in initial volume replacement, airway control, and recognition of the need for surgical intervention were factors complicating the care of these patients.

The adequacy of initial care of patients subsequently transferred to a trauma center with regard to neurologic, chest, abdominal, and orthopedic injuries has also been studied. Major departures from accepted standards of care, promoted by the ASCOT and the ACEP, in more than 70% of these cases were found. The care of patients initially treated at local community hospitals during initial management and subsequent transport to a referral trauma center was reviewed. Quality of care was assessed based on ATLS guidelines. Life-threatening deficiencies occur in 5% and serious deficiencies in 80% of cases reviewed, including inadequate cervical spine immobilization, inadequate intravenous access, and inadequate oxygen delivery. Veenema and Rodewald demonstrated that, while initial triage and management of rural trauma victims at a Level III trauma center prior to Level I transfer provide outcomes similar to MTOS data, there were still unexpected deaths.93

Timely transfer of major trauma victims to trauma centers improves patient care and subsequent outcome. Trauma centers not only provide the resources for the early management of severely injured patients, but can also provide more extensive support for the patient beyond the initial 24 hours.

There are few studies that have looked at specific criteria as markers for patients who would benefit from interhospital transfer. Lee et al. attempted to clarify specific anatomic criteria that would indicate the need for interhospital transfer from Level III centers.94 They found that the presence of three or more rib fractures was a marker for potential serious injury, as evidenced by significant differences in outcome when compared to patients with one or two rib fractures. A subsequent population-based study confirmed that these patients have a significantly higher mortality rate, higher ISS, and longer ICU and overall hospital stay.95 Clark et al. reviewed their experience with major hepatic trauma (Grade III or more) in patients transferred from rural facilities. However, they did not delineate specific transfer criteria.96Similar studies have looked at mechanistic and physiologic criteria as reasons for bypassing rural/local community hospitals or determining the need for a specific transport modality.


The question of whether air or ground transport is more appropriate for the transfer of the trauma victim is dependent on a number of factors. This includes the distance to be traveled, geography, weather, and overall patient status. Because outcome is directly related to time to definitive care, the quickest mode of transport that ensures patient safety should be chosen. Several options are available at many major trauma centers, including traditional ground transport and helicopter and fixed-wing air transport. The data on transport modality may not directly correlate to interhospital transfer because much of them come from analyzing transports from the scene of the accident rather than from one hospital to another.

Baxt and Moody found that patients transported from the scene of the accident by helicopter had a 52% reduction in mortality compared to those transported by ground.97 Similar results were found by Moylan et al. when they looked at factors improving survival in multisystem trauma patients who were transported by air versus ground.98 There were no differences in the prehospital times between these two sets of patients, and the air-transported patients were more frequently intubated and transfused blood, and had larger volumes of fluid given than the ground-transported patients.

The main benefit of air transport appears to be its use for long-distance transport. Several studies have shown that there is an improved survival in patients who need higher level of care when transported by air, and this benefit can be realized up to an 800-mile radius from the trauma center. This mode of transport may not be appropriate for short-distance transfer due to prolonged response time for interhospital transport. For local urban transport, helicopters offer no advantage over an organized ground transportation system, and the increased cost for air transport, especially that of helicopters, is probably not justified.

Trauma triage and the interhospital transfer process have many similarities. Both have the same goal: to minimize potentially avoidable deaths. In order to accomplish this, both attempt to accurately identify the trauma patient who will require the specialized skills and resources provided by a Level I or II trauma center. Both utilize the same type of limited information early in the course of events in order to make that decision.

While certain types of obvious injuries warrant expeditious transport of the trauma victim, it is best to look at all of the available information in terms of physiologic indices, mechanism of injury, comorbid factors, and known or suspected injuries. This approach allows one to assess potential problems that may be more appropriately handled at a major trauma center. If there is any doubt, it is in the patients’ best interest to be taken to a facility providing the highest level of care available.


Hospital care of the injured patient requires commitments from specific facilities to provide administrative support, medical staff, nursing staff, and other support personnel. The trauma center integrates the trauma care system by providing local or regional leadership. Trauma centers are categorized by level, as described below.

Image Level I Trauma Center

The Level I trauma center is a tertiary care hospital usually serving large inner-city communities that demonstrates a leadership role in system development, optimal trauma care, quality improvement, education, and research. It serves as a regional resource for the provision of the most sophisticated trauma care, from resuscitation to rehabilitation and managing large numbers of severely injured patients to immediate 24-hour availability of an attending trauma surgeon. Level I trauma centers address public education and prevention issues on a regional basis and provide continuing education for all levels of trauma care providers. They lead research efforts to advance care.

Image Level II Trauma Center

The Level II trauma center also provides definitive care to the injured and may be the principal hospital in the community or may work together with a Level I trauma center, in an attempt to optimize resources and clinical expertise necessary to provide optimal care for the injured victim. Its approach to trauma is generally not as comprehensive as the Level I facility. The attending trauma surgeon’s availability is equivalent and he or she must participate early in the care of the patient. Graduate education and research are not required.

Image Level III Trauma Center

A Level III trauma center generally serves a community that lacks Level I or II facilities. Maximum commitment is required to assess, resuscitate, and, when necessary, provide definitive operative therapy. For the major trauma patient, the principal role of the Level III center is to stabilize the injured patient and effect safe transfer to a higher level of care when capabilities for definitive care are exceeded. Transfer agreements and protocols are essential in a Level III trauma center. Education program for health care personnel may be part of a Level III center’s role, as the hospital may be the only designated trauma center in the community.

Image Level IV Trauma Center

A Level IV trauma center is usually a hospital located in a rural area. Level IV trauma centers are expected to provide the initial evaluation and care to acutely injured patients. Transfer agreements and protocols must be in place, since most of these hospitals have no definitive surgical capabilities on a regular basis.

Image Acute Care Facilities within the System

Many general hospitals exist within a trauma care system but are not officially designated as trauma centers. Circumstances often exist in which less severely injured patients reach these hospitals and appropriate care is provided. The system should provide for interfacility transfer of patients if a major trauma patient is mistriaged and registry entry for injured patients managed at nondesignated facilities.

Image Specialty Trauma Centers

Regional specialty facilities concentrate expertise in a specific discipline and serve as a valuable resource for patients with critical specialty-oriented injuries. Examples include pediatric trauma, bums, spinal cord injuries, and hand (replantation) trauma. Where present, these facilities provide a valuable resource to the community and should be included in the design of the system.


Rehabilitation is as important as prehospital and hospital care. It is often the longest and most difficult phase of the trauma care continuum for both patient and family. Only 1 of 10 trauma patients in the United States has access to adequate rehabilitation programs, although it is critically important to reintegrating the patient into society. Rehabilitation can be provided in a designated area within the trauma center or by agreement with a freestanding rehabilitation center.


A trauma system has to monitor its own performance over time and determine areas where improvement is needed. To achieve this goal, reliable data collection and analysis through a statewide or systemwide trauma registry is necessary. Information from each phase of care is important and must be linked with every other phase. Compatibility between data collection during different phases of care is important to accurately determine the effects of certain interventions on long-term outcome. The practical use of a system evaluation instrument is to identify where the system falls short operationally and allow for improvements in system design. This feedback mechanism must be part of the system plan for evaluation.

The implementation of trauma care systems coupled with trauma registry databases, injury severity indices, and measurable outcome indicators has led to improved validity for investigations across the entire spectrum of injury control research. The system also has to be evaluated by the American College of Surgeons Committee on Trauma Verification Review Committee or by inviting experts as outside reviewers in addition to internal review.


The systemwide QI program’s most important role is to monitor the quality of trauma care from incident to rehabilitation and create solutions to correct identified problems. The purpose of quality improvement is to provide care in a planned sequence, measure compliance with defined standards of care, and reduce variability and cost while maintaining quality. A comprehensive downloadable guide to this process is detailed on the American College of Surgeons Web site.

It allows health care providers to monitor several aspects of medical care using explicit guidelines to identify problems that have a negative impact on patient outcome. This is accomplished by establishing standards of trauma care and a mechanism to monitor the trauma care provided (surveillance), usually with audit filters designed to identify outliers.

Errors occur due to the complexity of trauma care and because of the involvement of multiple providers. It is of fundamental importance to make a distinction between process complexity and human errors when developing a quality improvement program in trauma.99102

A peer process must be established to review QA/QI problems.103 The process must be accurately documented, corrective action instituted and applied uniformly across the system, and the results reassessed. These principles apply to systemwide QA/QI as well as to the process within the hospital. Corrective action is taken through changes in existing policies or protocols, through education targeted at the problem, or by restriction of privileges.

A successful trauma system monitors the performance of the EMS agency and prehospital operations, individual trauma hospitals, and care in nondesignated hospitals.

The prehospital audit process should include timeliness of arrival, timeliness of transport, application of prehospital procedures and treatments, and outcomes. To develop this part of the quality improvement process, extensive involvement by the regional authority, the regional medical director, the provider agencies, and the trauma hospitals is required.

Standards of care are defined in relation to the availability of resources and personnel, timeliness of physician response, diagnosis, and therapy. These standards have been defined by the ACS and published in the Resources for Optimal Care of the Injured Patient.4 Guidelines or protocols are then developed and audit filters are established to monitor the guidelines. Audit filters are useful tools to provide continuous monitoring of established practices. Standard audit filters and complications that need to be monitored have been established by the ACSCOT and include timeliness of care, appropriateness of care, and death review. Tracking of complications and illnesses allows trends to be monitored over time. Death reviews should be conducted in an attempt to determine preventability. Guidelines reduce variability, and, consequently, fewer errors are made.

The process of quality improvement requires accurate documentation and this is achieved by using the trauma registry. The trauma registry provides objective data to support continuous quality improvement. The registry should be designed to collect and calculate response times, admission diagnoses, diagnostic and therapeutic procedures, discharge diagnoses, complications, costs, and functional recovery.

The trauma coordinator is of utmost importance in making the quality improvement process effective. This person assures timely recognition of problems, use of the registry to document problems, and that problems are resolved. Cases identified as noncompliant with established standards of care are reviewed at the hospital level and by a trauma medical audit committee overseeing the trauma system.103

Peer review identifies the problem, the results are documented and determination of problem recurrence is made, trends are identified, and a decision is made if more specific action for problem resolution is required.

Actions may include simple education of the staff or revision of the guidelines, or eventually development of new guidelines, hiring additional staff, or even removing a staff member. The monitoring process should continue after action was taken to determine its effectiveness. Quality improvement processes in trauma are a multidisciplinary task.


The development of trauma systems led to a significant reduction in the number of preventable deaths after injury. A preventable death rate of less than 1–2% is now widely accepted as ideal in a trauma system. However, a small number of patients continue to die, or eventually, to develop complications that could otherwise be avoided or prevented. These errors occur in different phases of trauma care (resuscitative, operative, and critical care phases), and are named provider related, as a group. These include events that lead to delays or errors in technique, judgment, treatment, or communication. A delay in diagnosis is defined as an injury-related diagnosis made greater than 24 hours after admission resulting in minimum morbidity. An error in diagnosis is an injury missed because of misinterpretation or inadequacy of physical examination or diagnostic procedures. An error in judgment is defined as a therapeutic decision or diagnostic modality employed contrary to available data. An error in technique occurs during the performance of a diagnostic or therapeutic procedure.102

According to the ACSCOT Resources for Optimal Care of the Injured Patient: 2006 document, an event is defined as nonpreventable when it is a sequela of a procedure, disease, or injury for which reasonable and appropriate preventable steps had been observed and taken. Potentially preventable is an event or complication that is a sequela of a procedure, disease, or injury that has the potential to be prevented or substantially ameliorated. A preventable event or complication is an expected or unexpected sequela of a procedure, disease, or injury that could have been prevented or substantially ameliorated.4

With regard to mortality, the same definitions apply. Nonpreventable deaths are defined as fatal injuries despite optimal care, evaluated and managed appropriately accordingly to standard guidelines (ATLS), and with a probability of survival, estimated by using the TRISS methodology, of less than 25%. A potentially preventable death is defined as an injury or combination of injuries considered very severe but survivable under optimal conditions. Generally these are unstable patients at the scene who respond minimally to treatment. Evaluation and management are generally appropriate and suspected care, however, directly or indirectly is implicated in patient demise. The calculated probability of survival varies from 25% to 50%.

A preventable death usually includes an injury or combination of injuries considered survivable. Patients in this category are generally stable, or if unstable, respond adequately to treatment. The evaluation or treatment is suspected in any way, and the calculated probability of survival is greater than 50%.

The causes of preventable deaths in trauma centers are different than those occurring at nontrauma hospitals. In nontrauma hospitals, preventable deaths occur because the severity or multiplicity of injuries is not fully appreciated, leading to delays in diagnosis, lack of adequate monitoring, and delays to definitive therapy. In trauma hospitals, the causes of preventable death include errors in judgment or errors in technique. In trauma centers the diagnostic modalities used are normally adequate, and delays in diagnosis or treatment are uncommon and have minimal impact on outcome.

These definitions are useful to monitor trauma system’s performance and to compare different trauma systems. Once preventable death rate reaches a plateau after trauma system implementation, system performance should focus on tracking provider-related complications. This approach has been proved adequate to identify problems and to implement solutions.


Different study designs have been used to evaluate trauma system effectiveness. The most common scientific approaches include panel review preventable death studies, trauma registry performance comparisons, and population-based studies. Panel review studies are conducted by a panel of experts in the field of trauma who review trauma-related deaths in an attempt to determine preventability. Well-defined criteria and standardized definitions regarding preventability have been used, but significant methodological problems (Table 4-4) can lead to inconsistencies in the results and interpretation of the data.16,103

TABLE 4-4 Limitations of Current Trauma System Evaluation Studies



Registry studies are frequently used to compare data from a trauma center or a trauma system with a national reference norm available, between trauma centers within the same system, or in the same trauma center at different periods. The MTOS23 has been used as the national reference, although several of its limitations have been recognized, compromising the reliability of the comparison with data from other systems or centers (Table 4-4). The advantages of registry-based studies include a detailed description of injury severity and physiologic data.

Population-based studies use information obtained from death certificates, hospital discharge claim data, or fatal accident reporting system (FARS) on all injured patients in a region. These methodologies of data collection and analysis are important to evaluate changes in outcome before and after, or at different time periods following the implementation of trauma systems in a defined region. Limited information on physiologic data, injury severity, and treatment is available.104 The limitations of the most commonly used databases in population-based studies are described in Table 4-4.

The data on trauma system effectiveness published in the literature are difficult to interpret due to great variability in study design, type of analysis, and definition of outcome variables. In an attempt to review the existing evidence on the effectiveness of trauma systems, the Oregon Health Sciences University with support from the NTHSA and the National Center for Injury Prevention and Control of the CDC organized the Academic Symposium to evaluate Evidence regarding the Efficacy of Trauma Systems, also known as the Skamania Symposium.105

Trauma care providers, policy makers, administrators, and researchers reviewed and discussed the available literature in an attempt to determine the impact of trauma systems on quality of patient care. The available literature on trauma system effectiveness does not contain class I (prospective randomized controlled trials) or class II studies (well-designed, prospective or retrospective controlled cohort studies, or case-controlled studies). There are several class III (panel studies, case series, or registry based) studies that were reviewed and discussed during the symposium. According to Mann et al. reviewing the published literature in preparation for the Skamania Symposium, it is appropriate to conclude that the implementation of trauma systems decreases hospital mortality of severely injured patients.106Independently of the used methodology (panel review, registry based, or population based), and despite the above-mentioned limitations of each study design, a decrease in mortality of 15–20% has been shown with the implementation of trauma systems. The participants of the symposium also concluded that not only mortality but also functional outcomes, financial outcomes, patient satisfaction, and cost-effectiveness should be evaluated in future prospective, well-controlled studies.

Outcomes data are difficult to interpret due to differences in study design. One recent area of interest has been in comparing outcomes in inclusive and exclusive systems. As mentioned previously, in an inclusive system, care is provided to all injured patients and involves all acute care facilities, whereas in exclusive systems specialized trauma care is provided only in highlevel trauma centers that deliver definitive care. In inclusive systems, patients may be transferred to a higher level of care (trauma center) after initial stabilization based on the availability of resources and expertise in the initial treating facility. Two problems arise: (a) delay in transfer and (b) dilution of trauma centers’ experience. Utter et al. have recently investigated whether mortality is lower in inclusive systems compared to exclusive systems. They concluded that severely injured patients are more likely to survive in states with the most inclusive trauma system, independent of the triage system in place. A possible explanation to these findings includes better initial care in referring hospitals.107 A more recent study confirms a mortality reduction of 25% in patients under the age of 55.61


Despite the experience acquired on trauma system development in the United States during the last three decades, trauma systems still face multiple problems and challenges. The financial aspect, linked to the problem of uncompensated care, has led to the closure of several trauma centers and the collapse of some trauma systems. Alternative and stable sources for funding indigent care have to be part of an agenda for legislative action in support of trauma systems. This is particularly important given recent published reports showing that the risk of death is significantly lower in trauma centers than nontrauma centers. In an important study, MacKenzie et al. compared rates of both in-hospital and 1-year mortality in trauma victims treated in trauma centers versus nontrauma centers. After risk and case mix adjustment, trauma centers had an in-house mortality of 7.6%, significantly less than nontrauma centers where mortality was 9.5%. After 1 year, trauma center mortality was 10.4% compared to 13.8% in nontrauma centers.61Funds for prevention strategies should also be provided, targeting particularly the pediatric and the elderly population. Table 4-5 lists the actual problems faced by regionalized trauma systems as documented through an SWOT analysis conducted by the Health Resources and Service Administration in 2003.

TABLE 4-5 Current Problems of Trauma Systems



One effort that has been developed recently is the Consultations for Trauma Systems document and accompanying process developed by the ACSCOT.12 It follows previous efforts to develop trauma systems and the original Model Trauma System Care Plan.108 The consultation provides two unique services: (1) an exceptional and experienced team enables examination and a knowledgeable perspective to optimize hospital and community trauma resources and (2) the consultant team brings the credibility of the ACSCOT to hospitals developing a trauma center. A more recent effort has led to the Model Trauma System Planning and Evaluation Program developed in collaboration with the HRSA of the U.S. Department of Health and Human Services.7 This is the most comprehensive tool available to help develop regional trauma systems.

As important is the issue related to the ideal number of trauma centers needed in an organized system. Many states with organized trauma systems, as well as many counties with developed trauma systems, have not performed a needs assessment prior to the implementation of the system. Similar to other fields of surgery and medicine, data suggest that the patient volume correlates with outcomes. Severely injured patients should be treated at high-volume trauma centers within a community, and the number of Level I trauma centers should be based on a needs assessment. Limiting the number of trauma centers and “concentrating” the experience of managing severely injured patients in Level I trauma centers improves outcomes, reduces costs, improves efficiency, facilitates transfers, and enhances education and research.3,5,109

Despite the realization that trauma systems reduce morbidity and mortality, there remain several barriers to full implementation. A trauma system agenda for the future has been recently written and endorsed as a template for going forward. Critical elements are defined in Table 4-6. It is imagined that trauma systems when fully implemented will enhance community health through an organized system of injury prevention, acute care, and rehabilitation that is fully integrated into the public health system of a community. In addition to addressing the daily demands of trauma, it will form the basis for disaster preparedness and possess the distinct ability to identify risk factors and early interventions to prevent injuries in a community while integrating a delivery of optimal resources for patients who ultimately need acute trauma care.

TABLE 4-6 Critical Targets for Future Trauma System Development


The availability of federal dollars to assist in the development of trauma systems will be essential. At the same time, a developing consensus to build trauma systems that do not cover designated trauma centers yet meet the needs of all components of the trauma patient will be equally critical. The biggest challenge in the future will be the implementation of what we already know how to do. Developing the political and public will to do so remains the challenge before us.


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