Trauma and injury account for 182, 479 deaths in 2007, with approximately 31,224 due to penetrating injuries, that is, firearms, and 65,474 secondary to blunt mechanisms, such as motor vehicle collisions and falls.¹ These statistics do not include the numerous morbidities that may also be associated with these injuries. It is difficult to address the world of trauma and acute care medicine without discussing “the golden hour;” and the “platinum ten minutes” referring to the fact that any trauma resuscitation is divided into either success or failure within the first hour of medical attention, and the initial minutes where critical interventions take place. While numerous debates have raged since the inception of this concept, the underlying idea of prompt and effective medical care starting from the point of patient contact in the field, and therefore the importance of prehospital management of the trauma patient, is indisputable.

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  Understand the initial prehospital management of the trauma patient, including triage and transport criteria.

  
  
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  Understand the prehospital management of specific injuries to the chest and abdomen and the surrounding controversies of their care.

The overall management of the trauma patient has not deviated as much as the care of other medical emergencies. This may be taken in the perspective of patients undergoing an acute myocardial infarction and the use of the defibrillator, various drugs, and transport destination centers. Alternatively, if a patient has undergone penetrating abdominal trauma, the response is similar to that performed in years past, with stabilization of the patient in the field and transportation of the patient to the nearest trauma center where the patient would receive definitive treatment in the operating room. Thus, this chapter, instead of going through the laborious task of delineating the relatively static role of prehospital trauma management, will instead explore some of the recent controversies along with the techniques and technologies that are being used in the prehospital field.

Triage of the trauma patient in the field is oftentimes a complex, challenging, and much debated issue among prehospital providers. The American College of Surgeons’ Committee on Trauma has defined an acceptable undertriage rate (seriously injured patient not taken to a trauma center) as 5%, whereas overtriage rates may be acceptably as high as 25% to 50%.² The relatively high allowance for the overtriage rate is tolerated so as to allow for an acceptable level of patients who may be undertriaged. Many studies have in fact reported overtriage rates to be as high as 90%.^3,4

The importance of successful triage by prehospital providers is further emphasized with the development of regionalized trauma systems. It has been shown that the regionalization of receiving facilities, that is, the designation of hospitals to care for certain conditions such as trauma, burn, hyperbaric, or poisons (venomization) has significantly reduced mortality and morbidity.⁵ Thus the decision of transport to one of these specialized facilities may be critical for both definitive patient care as well as the appropriate utilization of resources both at the hospital level as well as in the prehospital field: Indeed, not every patient involved in a “trauma” may require the use of a level 1 trauma center.

While it may not be as appreciated in large urban EMS systems with multiple trauma centers, effective trauma triage becomes particularly important in rural systems where in many instances, a critical decision must be made in choosing between ground and aeromedical transport to the most appropriate facility. For best outcomes, the prehospital triage criteria should be optimized such that patients may be classified as (1) serious injury requiring transport to a trauma center or (2) noncritical injury that may be treated at a local nontrauma receiving hospital.

Prehospital triage criteria typically include various combinations of physiologic, anatomic, and mechanistic criteria. Initial studies have shown that while mechanistic indicators are useful in identifying and subsequently transporting severely injured patients to trauma centers, the results trend toward overtriage.⁶ On the other hand, anatomic and physiologic criteria have generally added to the improvement of triage accuracy.^4,7 This, however, is not the case in blunt trauma where the reliable clinical assessment of internal organ damage may be severely limited.⁴

Various studies have shown mixed results in the reliability of EMTs and paramedics to effectively predict patients’ injury severity. One widely used triage criteria is the Prehospital Index (PHI) which consists of five field criteria: systolic blood pressure, heart rate, respiratory status, level of consciousness, and the presence of penetrating truncal injury. In a 2010 study, the combination of EMT judgment, PHI, and a mechanistic scale involving the quantity of damaging energy transfer to the patient (high velocity impact or HVI) identified patients who would benefit from care at a level 1 trauma center, albeit with low sensitivities (74.2%) and high rates of overtriage (85.1%).⁸ Another study showed that prehospital personnel with a similarly established triage scoring system (MAP, mechanism, anatomy, and physiology) used over a 10-year period were able to adequately distinguish patients in a rural environment that required helicopter transport to a trauma center with relatively high sensitivities, 93.8%, and an adequate rate of overtriage such that only a small increase in the rate of helicopter transports were recorded (7%-10%).⁹ When patient triage was subdivided to include the assessment of the severity of injury to individual body regions, it was not shown to improve accuracy.¹⁰ However, it has been shown that paramedics are best able to differentiate severe head injury, which is commonly based on a neurologic examination and determination of prehospital GCS score. A prehospital GCS <14 has been shown to be associated with severe head injuries with a sensitivity of 62% and specificity of 89%.^10,11 In contrast, paramedics were least able to identify severe blunt abdominal injuries.¹⁰ A 2014 study revealed that 36% of helicopter transported trauma victims had only minor injuries and that apparent risks for overtriage included falls, penetrating injury, and being uninsured.¹²

It has been reported that as much as 50% of injuries that eventually result in death occur at the scene with another 25% of these eventual deaths occurring within the first 24 hours of hospitalization.^13,14 Of the potentially survivable patients, one could surmise, that according to the dogma of trauma care, they would receive the most benefit by expeditious evaluation and care by prehospital personnel. Herein lies the question of how the patient would receive the most benefit: expeditious transport to an appropriate care center or thorough examination and potentially lifesaving interventions to be performed on the scene, such as basic airway management and hemorrhage control, and then transport for definitive care.

A major controversy in the prehospital care of trauma is the necessity of ALS (advanced life support) transport versus BLS (basic life support) transport. While the definitions of the levels of care may differ from system to system, in general the term ALS refers to a more sophisticated level of care potentially involving more invasive methods, including intravenous fluids, intubation, and the use of medications whereas BLS care typically involves patient assessment and temporizing measures for more definitive care at a hospital.

When dealing with trauma in the prehospital care setting, two strategies have typically been discussed: “scoop and run” versus “stay and play.” The former deals with expedited transport to a high acuity trauma center with minimal prehospital treatments and the later refers to stabilization of the patient on the scene before transport. The terminology is not strictly related to ALS versus BLS transport but rather it seems to reflect global differences between prehospital care: United States and Canada favor the more expedited “scoop-and-run” dogma as opposed to Europe, which trends toward the “stay–and-play” approach.

And while prehospital ALS, whether with an on-scene physician or not, has theoretical advantages, the evidence supporting its effectiveness for treating trauma is limited. This may be attributed to the fact that all ALS providers, including paramedics and physicians, are ultimately limited in the type of interventions they may perform in the prehospital setting (due to historical nonavailability of sophisticated imaging or operative maneuvers). In addition, some studies have suggested that prolonged prehospital interventions may even cause more harm than benefit as the time to perform these interventions delays definitive care.¹⁵ These findings have been shown to be dependent on the severity and location of the injury. For example, for patients with severe blunt head injury or who have sustained multiple injuries, these patients have been shown to have improved survivability with ALS care. However, it should be noted that these studies utilized air-medical transportation to definitive care.^16–18 In cases of multiple blunt trauma there has not been shown to be a difference between ALS and BLS care,^19–22 with some studies even suggesting improved care by BLS.^23,24 Of studies concerning penetrating or undetermined trauma, no difference in outcomes were observed among the relatively mildly injured patients, with 10% to 15% of those with an Injury Severity Score (ISS) greater than 15^22,25–28 with some studies showing improved outcomes for those treated by BLS.^29–33

In 2007, it was seen that of patients who suffered penetrating thoracic trauma, seven of 88 (8.0%) EMS-transported patients via ALS survived until hospital discharge, whereas 16 of 92 (17.4%) survived after police or private transportation. After identifying that prehospital procedures occurred in 88.6% of patients treated by ALS, Seamon et al showed that for each procedure, patients were 2.63 times more likely to die before hospital discharge.³³ This phenomenon of increased patient survivability with layperson transportation following severe injury (ISS greater than 15) was also seen in an earlier study as well.³⁴

On the other hand, smaller studies have shown the benefit of providing ALS care in cases of trauma. Small, uncontrolled studies have shown decreases in mortality in selective cases of falls and penetrating injuries.^35,36 Other studies have attempted to validate ALS prehospital care by comparing EMS systems among countries; however, comparison is oftentimes difficult³⁷ in that the term ALS is an ill-defined and heterogenous term that can be defined as care by two paramedics or on-scene physicians and can also differ in the method of transportation and may or may not include air-medical systems. The differences between paramedic driven and physician run ALS systems showed an overall improved intermediate survivability among those with physicians at the scene. However, when comparing between systems with the same provider type, significant variability was seen in overall patient outcomes by as much as a four-fold difference in overall death rates.³⁸ This heterogeneity highlights the fact that it is oftentimes difficult to make comparisons between ALS systems. A 2013 study by Seamon et al,³⁹ failed to show a benefit in outcomes when compared to BLS care of trauma patients. A 2014 Cochrane review study by Jayaraman et al, which included three studies meeting the study criteria, similarly concluded that there is currently no evidence that ALS training for ambulance crews improves outcome in trauma patients.⁴⁰

Thoracic injury accounts for as much as 25% of deaths from trauma or approximately 16,000 deaths annually in the United States (Figure 54-1). Many of the resulting injuries causing early death, including tension pneumothorax, cardiac tamponade, or excessive hemorrhage can be treated and oftentimes the resulting death can be prevented in the prehospital setting.

Procedures such as needle decompression and chest tube thoracostomy have been used in the prehospital setting, to varying degrees of success.⁴¹ Currently, the American College of Surgeons Advanced Trauma Life Support (ATLS) and Prehospital Trauma Life Support (PHTLS) courses both recommend the use of needle thoracostomy (NT) in the setting of tension pneumothorax as a bridging measure until definitive treatment with tube thoracostomy is established.^42,43

Needle thoracostomy converts the life-threatening tension pneumothorax into a smaller simple, open pneumothorax. As a result, the compromise in respiratory effort is relieved at the cost of a small, open pneumothorax. In addition, since the diameter of the needle is insignificant compared to the human airway, respirations are not negatively affected.¹⁸ While this is widely considered to be an easy, less invasive procedure that can be done in the prehospital setting, it is not without risks.^44–47 Complications have been shown to stem from delay of transport to a hospital for definitive care, misdiagnosis and misplacement of the needle thoracostomy, and inappropriate patient selection.^48,49

Often the reported complications stem from insufficient cannula length that is used to decompress the pneumothorax in relation to chest wall thickness.^48–50 Current ATLS guidelines recommend a 5-cm needle catheter with the needle placed in the anterior chest wall at the second intercostal space in the midclavicular line. This is in spite of the fact that most commercially available needle angiocatheters used in the United States are 4.4 cm. A recent study looked at the predictability of failure rates of needle thoracostomy based on mean chest wall depth and found that the standard 4.4 cm angiocatheter would be unsuccessful in 50% of cases.⁵¹

Other studies have shown that the use of needle decompression is a relatively safe procedure when performed by paramedics in urban as well as aeromedical settings^47,49,52 (Figure 54-2). Studies have revealed that for patients with severe thoracic injury (AIS >4), needle thoracentesis use varied from 0% to 22%.⁴⁴ Patients were seen to sustain gunshot wounds, stab wounds, motor vehicle collisions, or other forms of blunt trauma. These large studies showed that among paramedics based in urban settings, little to no vascular injury, infection, or other complications were seen due to needle decompression.^43,44

When dealing with tension pneumothoraces in the field, among the common signs and symptoms paramedics are taught to evaluate is tracheal deviation. It has been suggested to de-emphasize this physical finding from paramedic training in light of the fact that 0% to 1% of patients were reported to have this physical finding at the time of patient evaluation.^49,53 The frequency of inappropriate and inadequate needle decompression has been recently evaluated with the use of CT and ultrasound techniques. Blaivas has shown that out of 57 patients who had at least one needle thoracostomy attempted in the prehospital setting, 15 patients (26%) were reported to have no evidence of a pneumothorax on ultrasound examination or on CT.⁵⁴

In contrast, tube thoracostomy is less accepted in the prehospital setting for the treatment and management of a pneumothorax, hemopneumothorax, or hemothorax. In general, chest tubes are not inserted in the prehospital setting due to concerns of on-scene time, sterility and infection, and the increased training that is involved with performing a more complicated procedure. These, in combination with appropriate patient selection, correct technique, and tube placement, reported complications of uncontrolled hemorrhage, iatrogenic damage to the heart or lungs make this a controversial prehospital procedure when performed by nonphysician prehospital providers.^55,56 Some systems utilize formal tube thoracostomy performance only by a critical care level provider with advanced training or an adequately trained and equipped EMS physician.

Some studies comparing the use of needle and tube thoracostomy in the same EMS system have shown that while tube thoracostomy had longer on-scene times, fewer patients were pronounced dead on arrival at the hospital, all while taking into account similar ISS, length of hospital stay, and overall mortality.⁴⁹ Incidences of lung damage or infection have been reported to be similar to ED tube thoracostomies and/or were seen to not be a significant complication in the prehospital setting.^49,57

Another, perhaps more controversial, procedure is the role of the prehospital thoracotomy. While the emergency department thoracotomy is well established as the standard of care for certain instances of penetrating and blunt traumatic cardiac arrest, recent studies have continued to evaluate its efficacy with reported survival rates ranging from 1.8% to 27.5%.⁵⁸ Outcomes are drastically variable, with several reported mortalities as high as 100%, but it has been shown that survival improves with a decreased time lapse between arrest and definitive treatment in the operating room.^59–62 One of the first reported successful prehospital thoracotomies concluded that while its reported case study was successful, the practice itself should not be adopted as the prehospital standard of care.⁶³ US guidelines for the treatment of traumatic cardiac arrests report similar recommendations, stating that thoracotomies are “outside the remit of prehospital care.”⁶⁴ This is in stark contrast to many European EMS systems where physicians routinely are a part of prehospital care and are able to perform more invasive procedures than their US counterparts. In such cases, field thoracotomy may be reserved for single entry penetrating thoracic trauma with a witnessed arrest.

Much of the research and information on prehospital thoracotomies has been performed in Europe, and more recently in parts of Asia, where this has been the standard of care for many years. A recent study from Europe showed that out of 71 on-scene thoracotomies performed by physicians, 18% survived to hospital discharge.⁶⁵ Conclusions from the study suggested that survival was concurrent in patients with penetrating stab wounds and cardiac arrest secondary to pericardial tamponade, with better neurological outcome when thoracotomy was performed soon after the arrest.