Assessment and management of the injured patient in the prehospital setting should proceed in an orderly manner, despite the fact that the EMT must frequently make rapid decisions about patient care under adverse conditions. While the general approach is based on that taught in the ATLS course, one important modification is that the EMT first performs a “scene assessment” prior to evaluating an individual patient. Next, a “primary survey” is conducted to identify life-threatening conditions and initiate immediate therapy.
At the end of the primary survey the EMT considers whether life-threatening or potentially life-threatening injuries have been identified. If so, the patient is expeditiously packaged and transported to the closest appropriate facility. Definitive care for severe, uncontrolled internal hemorrhage cannot be provided in the field, and surgery is usually required. Interventions such as direct pressure on a bleeding wound and infusion of intravenous fluids are not substitutes for rapid transportation to an appropriate facility with immediate surgical capabilities.
In the prehospital setting, assessment of the patient actually begins before reaching the patient’s side. As an EMS crew is dispatched to a scene, they begin to consider numerous factors that may play a role in caring for the patient, as well as ensuring their safety and that of the patient. These factors include such things as mechanism of injury, environmental conditions, and hazards present at the scene. The important aspects of this assessment can be divided into the following two key categories: safety/standard precaution and situation.
EMS personnel must first evaluate the safety of the scene; that is, they must not enter into a situation that puts their health and well-being at risk as this puts them in jeopardy of becoming patients as well. EMS workers are dependent on law enforcement personnel to ensure that the scene has been cleared of violent assailants and their weapons.56 In addition to their personal safety, the EMS providers need to consider concerns that threaten the safety of the patient. The scene of a traumatic incident may include dangers such as traffic, downed power lines, hazardous materials, and harsh environmental conditions. In light of incidents of terrorism there is heightened concern of chemical, biological, or nuclear contamination of a scene, or secondary devices planted with the intent of killing rescuers. Providers should assess for need for at scene decontamination prior to transport.
One hazard ubiquitous to virtually all trauma scenes is blood. Blood and other body fluids may contain communicable diseases including hepatitis and human immunodeficiency viruses. In any patient encounter, health care workers are encouraged to employ measures to decrease the risk of contracting these pathogens. Standard precautions involve the use of impermeable gloves, gowns, masks, and goggles. In addition to wearing this protective gear, EMS providers must also exercise caution when handling sharp devices, such as needles that are contaminated with a patient’s blood or body fluid.
The second component of the scene assessment is evaluation of the situation. The EMS providers should consider the following issues: the number of patients and their ages; the need for specialized personnel or equipment (power company, heavy rescue); the need for additional EMS units, including summoning an air medical helicopter; the need for a physician at the scene to assist with triage; and the possibility that the traumatic event was triggered by a medical emergency (acute myocardial infarction or a cerebrovascular accident). Because the EMS personnel are essentially the “eyes and ears” of the emergency physician and trauma surgeon at the scene, they are in the position to observe key data about the mechanism of injury.
An understanding of the mechanism of injury assists in evaluating the patient for potential injuries (see Chapter 1). Certain mechanisms frequently result in specific injury patterns. Recognition of the mechanism may guide providers in the assessment of the patient. If the incident involves a motor vehicle crash, the EMS crew should evaluate the type of collision (frontal, rear, or lateral impact, etc) and note the degree of damage to the vehicles. The location of the patient at the time of the crash and the use of restraints or protective gear is also valuable information.
After assessing the scene, EMS personnel perform a primary survey of the patient (see Chapter 10). As taught in ATLS, this survey serves to identify life-threatening or potentially life-threatening conditions. While it is taught in a stepwise A–B–C–D–E approach, one must remember that many aspects of this evaluation can be done simultaneously. In the event of external massive hemorrhage, bleeding should be addressed first. In the event of significant danger to prehospital personnel, such as the presence of an active shooter, a consensus group has recommended a “THREAT” approach. This procedure consists of steps as follows: (1) threat suppression, (2) hemorrhage control, (3) rapid extrication to safety, (4) assessment by medical providers, and (5) Transport to definitive care.56 EMS personnel employ a “treat as you go” philosophy, wherein care is initiated for life-threatening conditions as they are identified. Thus, the primary survey establishes a framework for setting priorities for management.
Management of the airway is given highest priority, but care must be taken not to aggravate a potential injury to the cervical spine (see Chapter 11). One EMS provider applies manual in-line stabilization to the head and neck while a coworker begins assessment and management of the airway. This stabilization of the cervical spine is continued either until the patient is completely immobilized on a long backboard or until it is determined that the patient does not require spinal immobilization.
All EMS providers, regardless of their level of training, must master the “essential skills” of airway management.44 These skills include the following: manually clearing the patient’s airway of foreign material; manually opening the airway using the trauma jaw thrust or trauma chin lift; suctioning the oropharynx; and inserting basic oral or nasal airways. An algorithm for prehospital management of the airway is provided (Fig. 7-1).50
Airway management. (Reproduced with permission from Salomone JP, Pons PT, McSwain NE, eds. PHTLS: Prehospital Trauma Life Support. 7th ed. St. Louis: Mosby; 2011:140. Copyright © Elsevier.)
While this has long been the “gold standard” for securing an airway in the hospital, its role in prehospital care has become increasingly controversial. This skill is typically limited to advanced providers, though all levels of EMTs have now been taught to safely insert endotracheal tubes. The use of this technique is almost universally accepted at the EMT-Paramedic level throughout the United States. A limited number of communities have allowed EMT-Bs to be trained in endotracheal intubation, as well. In most EMS systems, the success rate for endotracheal intubation exceeds 90%. With good, medical direction and field preceptors, training in endotracheal intubation can be successfully accomplished.57
Because of the concern of potential fractures of the cervical spine, endotracheal intubation should be performed concurrently with in-line stabilization of the cervical spine.58,59 While intubation is most commonly accomplished via the orotracheal route using a laryngoscope, other techniques include digital intubation, and retrograde intubation, although these are rarely utilized in the field.60,61,62 Video laryngoscopy is becoming increasingly utilized in the field by ALS and HEMS personnel. It is not clear yet if this will improve the success rate with less time expended with the procedure. Success of rapid sequence intubation is certainly tied to concentrated experience. A study in San Diego showed that intubation of patients with traumatic brain injuries (TBI) by ground ALS crews led to increased mortality, while intubation by air medical crewmembers led to better survival.63
Indications for endotracheal intubation in the field include the following:
Inability of patient to maintain an airway due to altered level of consciousness (Glasgow Coma Scale [GCS] score <8)
Need for assisted ventilations
Threatened airway (eg, respiratory burns, expanding hematoma of the neck)
Concern has arisen that endotracheal tubes placed in the prehospital setting may be misplaced or may become dislodged more commonly than previously believed.64 Once endotracheal intubation has been performed, care should be taken to confirm proper placement using a combination of clinical assessments and adjunctive devices. The clinical assessments include presence of bilateral breath sounds and the absence of ventilatory sounds over the epigastrium, chest rise with ventilation, and the provider watching the tube pass through the vocal cords. Adjuncts that help confirm a successful intubation include colorimetric CO2 detectors, capnography, and the esophageal detector device.65 Following intubation, the tube is carefully secured and its position checked each time the patient is moved. A recent publication suggests that continuous capnography in the prehospital setting may significantly reduce the incidence of misplaced or dislodged ET tubes.66
A number of EMS services, especially air medical programs, permit their providers to perform rapid sequence intubation (RSI). This involves the administration of both a sedating agent and a neuromuscular blocking agent prior to endotracheal intubation. In skilled hands, this technique can facilitate effective airway control in patients when other methods fail or are otherwise unacceptable (eg, the patient with trismus). The role of RSI in the prehospital setting is controversial, primarily because of both concerns related to the risks of losing a partially patent airway by administration of a paralytic agent and data suggesting that patient outcomes may be compromised when RSI is performed by EMS personnel.
With adequate medical control, several studies have documented that EMS personnel can safely perform this procedure.67,68,69 Data from one case-control study, however, demonstrated an interesting paradox. While paramedics using RSI had a higher success rate at performing endotracheal intubation, patients with a suspected severe traumatic brain injury (TBI) who were intubated with RSI had a higher mortality than did those in the control group.70 Davis et al71 recently published the findings of an expert panel on the role of prehospital RSI.
Wang and Yealy72 reviewed the data on prehospital intubation and concluded that there is little literature to support maintaining endotracheal intubation as the standard airway of choice. More studies have documented worsened outcomes than improved outcomes. If intubation is utilized, the EMS systems must carefully review each intubation attempt and ensure that it is being performed safely. Most children can maintain adequate oxygenation/ventilation with bag valve mask assistance and do not necessarily require endotracheal intubation.73
These are devices that are inserted without a laryngoscope (ie, blindly) into the hypopharynx. Although various models differ in design, properly positioned devices have openings that allow for passage of air from the device into the adjacent glottic opening to ventilate the lungs. Some devices have two ports and ventilations are then administered through the port that results in chest excursion and breath sounds (Combitube, Nellcor, Typo Healthcare, Pleasanton, CA). A similar alternative has a single ventilation port making it even easier to use (King LT airway, King Systems, Noblesville, IN).
Another supraglottic device is the laryngeal mask airway (LMA) (LMA North America, San Diego, CA), consisting of an inflatable silicone ring attached to a silicone tube. This device is blindly inserted into the hypopharynx so that the ring seals around the glottic opening. Ventilation is then provided through the tube. This device has replaced endotracheal intubation for general anesthesia in a significant percentage of shorter operations, especially in Great Britain. LMAs have been popular in the prehospital setting in Europe and with some air medical services in the United States.74
The primary advantage of supraglottic airways is that minimal training is necessary to achieve competency because of their design and the blind insertion. A potential disadvantage of these devices is that the risk of aspiration is believed to be greater than with endotracheal intubation. Supraglottic devices are valuable backup (“rescue”) airways when endotracheal intubation cannot be accomplished. Because of the controversies with endotracheal intubation, these airways are increasingly utilized as the initial airway of choice, although these airways can be problematic because of potential risks.75 This is especially true in the urban setting where transport times are generally brief. It may be best to fall back on bag-valve-mask (BVM) if ventilation appears difficult. Use of either endotracheal intubation or a supraglottic airway is a low-volume, high-risk procedure and requires rigorous medical oversight.
This involves the insertion of a large-bore needle through the cricothyroid membrane and connecting it to high-pressure oxygen. The lungs are then insufflated periodically. This technique possesses the following advantages: it does not require paralysis, is less invasive than surgical cricothyroidotomy, affords easy access and insertion, and requires minimal education and very basic equipment. The technique has been demonstrated experimentally to be safe and effective even in the presence of complete obstruction of the airway. While oxygenation is adequate, studies have shown that the patient may become hypercarbic.77 Percutaneous transtracheal ventilation (PTV) is indicated when an injured patient is unable to be intubated and cannot be ventilated using a BVM device or an alternative airway.
This involves incising the skin and the cricothyroid membrane, followed by the insertion of a small endotracheal or tracheostomy tube. Because it is highly invasive, complications have included significant hemorrhage and injury to adjacent nerves, blood vessels, and the larynx. Air medical crews have utilized surgical cricothyroidotomy in the prehospital setting for several decades with good success. Use of this procedure by out-of-hospital personnel requires strong medical oversight and intense training. It should be reserved for a situation of “can’t intubate-can’t ventilate.”75
The patient’s ventilatory status (“breathing”) is next examined. If the patient’s ventilatory rate is 10 or less, ventilations should be assisted with a BVM device connected to 100% oxygen. Rapid, shallow breaths indicate inadequate minute ventilation and require assistance with a BVM. Auscultation of breath sounds should be performed during the primary survey if the patient has an abnormal ventilatory rate or evidence of respiratory distress. Most patients who have suffered an injury benefit from supplemental oxygen. Pulse oximetry should be monitored, and oxygen administered to maintain an Spo2 of at least 90% if not more.
Prehospital care providers must exercise caution while providing ventilatory support, as deleterious effects may ensue. Hyperventilation by EMS personnel in one study was associated with increased mortality in patients with a suspected TBI.76 Additionally, data from animal models suggest that hyperventilation resulted in auto-positive end-expiratory pressure (PEEP) that further compromised the hemodynamic status of a hypovolemic swine.77 For an adult patient, a reasonable tidal volume of 350–500 mL delivered at a rate of 10 breaths/min is probably sufficient to maintain a satisfactory oxygen saturation while minimizing the risk of hyperventilation. Continuous pulse oximetry and capnography can help guide the ventilatory support.
Assessment of a patient’s circulatory status involves examining for external hemorrhage and evaluating the adequacy of perfusion. Most life-threatening external hemorrhage can be controlled with direct pressure. If manpower is limited, a pressure dressing with gauze pads and an elastic bandage can be placed around an extremity. Should direct pressure alone not control bleeding in an extremity, a tourniquet should be applied just proximal to the site of hemorrhage and tightened until bleeding ceases. A second tourniquet may be required to obliterate the distal pulse and control bleeding. Improvised, noncommercial tourniquets have not been shown to be effective. No published data document any significant decrease in hemorrhage when a bleeding extremity is elevated, and such manipulation may result in the conversion of a closed fracture to an open one. The efficacy of applying pressure over “pressure points” in the axilla and groin has also not been studied in the prehospital setting and is labor intensive. In the operating room, arterial tourniquets have been used safely for periods of 114–150 minutes. Options for a tourniquet include a blood pressure cuff, and the use of a readily available manufactured tourniquet.78 If a manufactured tourniquet is used, it should be one that has been tested and recommended by the Committee on Tactical Combat Casualty Care (CoTCCC).79
A sample protocol for application of a tourniquet is described as follows and is shown in Fig. 7-2.
Protocol for tourniquet application. (Reproduced with permission from Salomone JP, Pons PT, McSwain NE, eds. PHTLS: Prehospital Trauma Life Support. 7th ed. St. Louis: Mosby; 2011:201. Copyright © Elsevier.)
Multiple studies have looked at the outcomes of casualties who had tourniquets applied for their extremity wounds.80,81,82,83 The data demonstrated that prehospital use of tourniquets was lifesaving and that complications were low. Less than 2% of the patients suffered transient nerve palsy at the level where the tourniquet was applied, and no limbs were sacrificed because of use of a tourniquet. In patients who had a tourniquet on for 2 hours or less, 28% required fasciotomy, while a slightly higher percentage (36%) required fasciotomy if the tourniquet was in place more than 2 hours.
A topical hemostatic agent should be considered for significant external hemorrhage from body areas not amenable to placement of a tourniquet (neck, torso, axilla, and groin). The CoTCCC currently recommends Combat Gauze that is impregnated with kaolin clay as the topical hemostatic agent of choice.84 Civilian and military experience have found this agent to be safe and effective.85,86
Perfusion is assessed primarily by evaluating pulse rate and quality, skin color, temperature, and moisture. Time should not be taken in the primary survey to measure blood pressure. Even mild tachycardia (heart rate >100/min) should always make one consider that the injured patient is hypovolemic. Significant tachycardia (>114/min), weak peripheral pulses, and anxiety are associated with loss of 30–40% of the blood volume of an adult.53 A new patient monitoring modality utilizing noninvasive tissue oxygen saturation (Sto2) shows promise as a way to determine early hemorrhagic shock.87,88 It must be noted that even one drop in systolic blood pressure while monitoring the patient may be enough to indicate early hemorrhagic shock.89
Traumatic Cardiopulmonary Arrest
Trauma patients who are found to be in cardiopulmonary arrest require special consideration. Unlike cardiopulmonary arrest associated with an acute myocardial infarction, most patients who suffer cessation of their vital signs prior to the arrival of EMS have exsanguinated. Cardiopulmonary resuscitation (CPR), defibrillation, antidysrhythmic medications, and crystalloid resuscitation will not reverse this. Attempts at resuscitation are typically futile and place the EMS personnel at unnecessary risk from automobile crashes during emergency transport and exposure to blood. The National Association of EMS Physicians and the ACSCOT have collaborated on a position paper that endorses the following guidelines90:
For victims of blunt trauma, resuscitation efforts may be withheld if the patient is pulseless and apneic on the arrival of EMS.
For victims of penetrating trauma, resuscitation efforts may be withheld if there are no signs of life (papillary reflexes, spontaneous movement, or organized cardiac rhythm on the electrocardiogram >40/min).
Resuscitation efforts are not indicated when the patient has sustained an obviously fatal injury (such as decapitation) or when evidence exists of dependent lividity, rigor mortis, and decomposition.
Termination of resuscitation should be considered in trauma patients with an EMS-witnessed cardiopulmonary arrest and 15 minutes of unsuccessful resuscitation including CPR.
Termination of resuscitation should be considered for a patient with traumatic cardiopulmonary arrest who would require transport of greater than 15 minutes to reach an emergency department or trauma center.
Victims of drowning, lightning strike, or hypothermia, or those in whom the mechanism of injury does not correlate with the clinical situation (suggesting a nontraumatic cause) deserve special consideration before a decision is made to withhold or terminate resuscitation.
During the primary survey, the EMS provider assesses neurologic function by evaluating the patient’s GCS score and pupillary response. The GCS score comprises three components including eyes, verbal, and motor.91 If a painful stimulus is required to complete the assessment, the EMT can either apply pressure to the nail bed or squeeze the axillary tissue. If the patient has an altered level of consciousness (GCS <15), pupillary response to light is assessed. Any belligerent, combative, or uncooperative patient should be considered to be hypoxic or have a TBI until proven otherwise. In a trauma patient, a GCS score of less than or equal to 13, seizure activity, or a motor or sensory deficit are all reasons for concern. An important corollary to this assessment is to try to ascertain if the patient is anticoagulated, if possible.
Exposure and Environmental Control
The final part of the primary survey involves a quick scan of the patient’s body to note any other potentially life-threatening injuries. In general, this requires removal of the patient’s clothes, but environmental conditions and the presence of bystanders may make this impractical. Hypothermia from failure to preserve body heat can contribute to a serious coagulopathy in the trauma patient.
Heavy, dark colored woolen clothing may absorb significant amounts of blood. On occasion, patients may have more than one mechanism of injury, that is, blunt trauma from a motor vehicle crash that occurred while trying to flee the assailant who had shot them. Injuries cannot be treated unless they are identified.
On completion of the primary survey, the EMS provider determines whether or not the patient is critical (Fig. 7-3). Because the primary survey involves a “treat as you go” philosophy, airway management, ventilatory support, and control of external hemorrhage are initiated as the problems are identified. Massive external hemorrhage takes precedence over other assessments.
Prehospital care overview. (Reproduced with permission from Salomone JP, Pons PT, McSwain NE, eds. PHTLS: Prehospital Trauma Life Support. 7th ed. St. Louis: Mosby; 2011:429. Copyright © Elsevier.)
When a critically injured patient is identified (Table 7-3), scene time should ideally be less than 10 minutes, unless extenuating circumstances such as entrapment or an unsafe scene preclude this. A large multicenter prospective study demonstrated no association between EMS intervals and mortality of injured patients with physiologic abnormalities in the field.92 On-scene times is one of the most important factors to be scrutinized by medical direction in the quality control process.
TABLE 7-3Critical Trauma Patient ||Download (.pdf) TABLE 7-3 Critical Trauma Patient
Limit scene time to 10 min or less when any of the following life-threatening conditions are present:
Inadequate or threatened airway
Impaired ventilation as demonstrated by the following:
Abnormally fast or slow ventilatory rate
Hypoxia (Spo2 <95% even with supplemental oxygen)
Open pneumothorax or flail chest
Significant external hemorrhage or suspected internal hemorrhage
Shock, even if compensated
Abnormal neurologic status
GCS score ≤13
Sensory or motor deficit
Penetrating trauma to the head, neck, or torso, or proximal to the elbow and knee in the extremities
Amputation or near amputation proximal to the fingers or toes
Any trauma in the presence of the following:
History of serious medical conditions (eg, coronary artery disease, chronic obstructive pulmonary disease, bleeding disorder)
If indicated, spinal immobilization should be performed expeditiously and the patient moved to the ambulance. Time is not taken to splint each individual fracture. For the critically injured patient, immobilization to the long backboard provides satisfactory immobilization of potential musculoskeletal injuries. A recent position statement from NAEMSP and ACSCOT discusses the appropriate use of spinal immobilization.93,94
Because definitive care cannot be provided to the critically injured patient in the field, EMS personnel must realize that initiation of transport to the closest appropriate facility demonstrates good judgment. Originally developed by the ACSCOT, the Field Triage Decision Scheme was recently revised by a national expert panel convened by the Centers for Disease Control and Prevention (CDC) (Fig. 7-4).95 The revision has been endorsed by more than 35 national EMS or trauma organizations. According to this algorithm, patients who meet specific anatomic or physiologic criteria should be transported to the highest level of care in the system, typically a level I or II trauma center. Patients who meet mechanism of injury criteria should be transported to the closest trauma center, which need not be a level I or II. Protocols should be written so that EMS personnel may bypass a closer hospital in order to take a patient with life-threatening injuries to a trauma center based on state or regional guidelines.
Field triage decision scheme. EMS, emergency medical services. (Reproduced from Sasser SM, Hunt RC, Sullivent EE, et al. Guidelines for field triage of injured patients: recommendations of the national expert panel on field triage. MMWR. 2009;58:1. Adapted from American College of Surgeons. Resources for the Optimal Care of the Injured Patient. Chicago: American College of Surgeons; 2006.)
*The upper limit of respiratory rate in infants is 0.29 breaths per minute to maintain a higher level of overtriage for infants.
†Trauma centers are designated level I–IV. A level I center has the greatest amount of resources and personnel for care of the injured patient and provides regional leadership in education, research, and prevention programs. A level II facility offers similar resources to a level I facility, possibly differing only in continuous availability of certain subspecialties or sufficient prevention, education, and research activities for level I designation; level II facilities are not required to be resident or fellow education centers. A level III center is capable of assessment, resuscitation, and emergency surgery, with severely injured patients being transferred to a level I or II facility. A level IV trauma center is capable of providing 24-hour physician coverage, resuscitation, and stabilization to injured patients before transfer to a facility that provides a higher level of trauma care.
§Any injury noted in step two or mechanism identified in step three triggers a “yes” response.
¶Age <15 years.
**Intrusion refers to interior compartment intrusion, as opposed to deformation which refers to exterior damage.
††Includes pedestrians or bicyclists thrown or run over by a motor vehicle or those with estimated impact 0.20 mph with a motor vehicle.
§§Local or regional protocols should be used to determine the most appropriate level of trauma center within the defined trauma system; need not be the highest-level trauma center.
¶¶Age > 55 years.
***Patients with both burns and concomitant trauma for whom the burn injury poses the greatest risk for morbidity and mortality should be transferred to a burn center. If the nonburn trauma presents a greater immediate risk, the patient may be stabilized in a trauma center and then transferred to a burn center.
Infusions of crystalloid solutions and blood transfusion are the mainstays of therapy for the in-hospital treatment of severe hypovolemic shock (see Chapter 12). Because it requires refrigeration and typing, blood is not typically available in the prehospital environment; however, packed red blood cells and plasma are becoming increasingly used by critical care air and ground services. Isotonic crystalloid solutions, such as lactated Ringer’s or normal saline (0.9% sodium chloride), can be used for volume resuscitation. Although hypertonic saline (7.5% sodium chloride) initially showed promise, a meta-analysis of several studies, as well as a more recent randomized controlled trial failed to demonstrate an improvement in survival rates compared to patients treated with isotonic solutions.96
En route to the receiving facility, the EMS providers should insert two large-bore (14- or 16-gauge) intravenous catheters in veins of the forearm or antecubital area or use intraosseous access. If possible, lactated Ringer’s solution (or normal saline) should be warmed (102°F/38.8°C) prior to administration. Fluid resuscitation in the prehospital setting must be based on the clinical scenario.53 If the patient has suspected uncontrolled hemorrhage in the thorax, abdomen, or retroperitoneum, fluid infusions should be titrated to maintain a systolic blood pressure (SBP) in the range of 80–90 mm Hg (mean arterial pressure of 58–65 mm Hg) in the hope of perfusing vital organs while limiting the risk of increased, uncontrollable internal hemorrhage. If the patient has a suspected injury to the central nervous system injury (TBI or injury to spinal cord), intravenous fluids should be administered at a rate sufficient to maintain the systolic blood pressure (SBP) at 90 mm Hg (Fig. 7-5). If the patient has identifiable shock that resulted from external hemorrhage that has been controlled, fluids are titrated to maintain a normal pulse rate and blood pressure. If the patient again becomes hypotensive, further intravenous fluids should be titrated to maintain SBP in the range of 80–90 mm Hg.
Algorithm for the prehospital management of TBI. (Reproduced with permission from Salomone JP, Pons PT, McSwain NE, eds. PHTLS: Prehospital Trauma Life Support. 7th ed. St. Louis: Mosby; 2011:240. Copyright © Elsevier.)
Controversy exists regarding the role of therapy with intravenous fluids in the prehospital setting. No published study has ever demonstrated an improvement in survival resulting from the prehospital administration of fluids. An analysis of almost 777,000 patients from the National Trauma Data Base showed that administration of intravenous crystalloids by EMS personnel increased mortality.97
Although further studies will be needed to clarify this issue, EMS providers should never delay transport simply to initiate intravenous therapy. In one sense, the most important fluid in the prehospital care of critically injured patients is fuel—to transport patients rapidly to the closest appropriate facility.
Secondary survey refers to a more thorough history and physical examination. For the patient with life-threatening conditions identified in the primary survey, the EMS provider performs the secondary survey when those conditions have been addressed and are stable or improving and the patient is being transported. If the primary survey fails to indicate that the injured patient is critical, then the provider proceeds on to the secondary survey.
This brief history from the patient or family includes the following:
Allergies to medications
Prescription or over-the-counter medications
Pertinent past medical history
Recall of events leading up to the injury
This complete physical examination begins with obtaining a complete set of vital signs. Injuries to the head, neck, chest, abdomen, pelvis, and extremities are noted. The patient is then turned using the log roll maneuver if a spinal injury is suspected, and the patient’s back is examined. Finally, a neurologic examination that involves reassessing the GCS score, pupillary reaction, and motor and sensory functions in the extremities is completed.
Because of the high concentration of blood vessels in the skin and soft tissues of the scalp, face, and neck, even a small wound can result in serious external hemorrhage. EMS providers and other health care workers often fail to appreciate that patients with a complex scalp wound may bleed sufficiently to develop shock. A compression dressing created with gauze pads and an elastic bandage often provides satisfactory control of hemorrhage. Hemostatic dressings can also be useful for uncontrolled scalp bleeding.
TBI remains one of the leading causes of mortality in injured patients. Secondary brain injury refers to the extension of the original injury and may result from numerous causes. These include hypoxia, hypocapnia and hypercapnia, anemia, hypotension, hypoglycemia and hyperglycemia, seizures, and intracranial hypertension as the result of edema or mass effect. Optimal prehospital care of the patient with a TBI involves preventing secondary brain injury, maintaining cerebral perfusion pressure (mean arterial pressure minus intracranial pressure), and expeditious transfer to a facility capable of caring for the injury.
A patient with a severe TBI may be unable to control his or her airway, and endotracheal intubation should be considered for patients with a GCS score of 8 or less, although an alternative airway device may provide a satisfactory airway. Ventilatory support should be administered, and the patient maintained eucapnic as prophylactic hyperventilation is no longer indicated.98,99 Data from patients with TBI indicate that those who arrive in the emergency department with either hypocapnia (arterial pco2 <30 mm Hg) or hypercapnia (pco2 >45 mm Hg) have poorer outcomes compared to those who arrive in a eucapnic condition.100 As indicated above, providers with greater experience and the availability of continuous end tidal capnography led to better survival of patients with a TBI who had RSI performed by HEMS providers than by ALS paramedics in San Diego.63
Blood loss should be minimized by controlling external sources and splinting fractures as appropriate. Because of the risk of an associated injury to the spine, patients with a suspected TBI should undergo spinal immobilization. Intravenous fluids should be initiated en route to the receiving facility with a goal of maintaining the SBP at 90 mm Hg. During prolonged transport, blood glucose can be monitored and dextrose administered if the patient is hypoglycemic. Benzodiazepines are appropriate for control of seizures, but they should be carefully titrated intravenously because of the risk of hypotension and respiratory depression.
Intracranial hypertension may cause cerebral herniation and brain death, but it cannot be measured in the prehospital setting. Signs of possible intracranial hypertension include the following: a decline in the GCS score of 2 points or more, development of a sluggish or nonreactive pupil, development of hemiplegia or hemiparesis, or Cushing’s phenomena (bradycardia associated with arterial hypertension).
Flail Chest and Pulmonary Contusion
In the prehospital setting, the administration of oxygen and ventilatory support are the primary therapies for a flail chest and suspected pulmonary contusion (see Chapters 24, 25, 26). Oxygen saturation should be kept at 95% or higher by applying supplemental oxygen. If these measures fail to provide adequate oxygenation, ventilations should be assisted and endotracheal intubation considered if the patient’s tidal volume appears inadequate.
Tension pneumothorax should be suspected whenever the following three criteria are identified: increasing respiratory distress or difficulty ventilating with a BVM device, decreased or absent breath sounds, and hemodynamic compromise. Needle decompression of the pleural space can be lifesaving.50,106 An intravenous catheter at least 12 gauge in diameter should be used and should be left in place. There is no need to create a one-way (“flutter”) valve as any air exchange through the catheter is clinically insignificant. Recent data suggest that a catheter length of at least 8 cm is necessary to reach and decompress the pleural space.101
An open pneumothorax should be sealed with an occlusive dressing. One of the four sides of the dressing may be left untaped so that air can decompress from the pleural space as needed. After an occlusive dressing has been applied to an open pneumothorax, any signs of a developing tension pneumothorax should prompt the EMS worker to remove the dressing. If this does not result in improvement of the patient’s status, needle decompression should be considered.
Pericardial tamponade is generally encountered following penetrating trauma to the heart; however, it may be a complication of a blunt cardiac rupture. In the prehospital setting, the classic symptoms of Beck triad (elevated venous pressure, muffled heart tones, and hemodynamic compromise) may be difficult to identify. While some EMS systems permit ALS personnel to perform pericardiocentesis if pericardial tamponade is suspected, the emphasis should be placed on transporting that patient with a suspected tamponade to a facility that has immediate surgical capabilities.
In the absence of an obvious sign such as a bullet wound, intra-abdominal hemorrhage is difficult to identify in the prehospital setting, especially in the unconscious trauma patient (see Chapters 27, 28, 29, 30, 31, 32, 33, 34). Unexplained hypovolemic shock should lead the EMS provider to suspect this condition. Management involves rapid transport to a facility that offers immediate operative intervention. A FAST (focused assessment for the sonographic evaluation of the trauma patient) examination is becoming increasingly available in air and ground EMS units and can help with triage.
The presence of a severe pelvic fracture may be suspected if the EMS provider finds instability on examination of the pelvis, especially if the patient has evidence of hypovolemic shock (see Chapter 35). Pelvic binders, which are often placed on hypotensive trauma patients with proven pelvic fractures in the hospital, have limited utility in the field. EMS providers may not be able to identify a fractured pelvis on physical examination alone and the pelvic binders are costly. These binders may be useful in the setting of a hypotensive trauma patient with a known pelvic fracture who requires interfacility transport.
Prehospital management of the injured pregnant patient focuses on adequately resuscitating the mother, especially if shock is present (see Chapter 37). In the third trimester, pregnant individuals may exhibit hypotension while lying supine due to compression of the inferior vena cava by the uterus. Supine hypotension is treated by gently rolling the mother into the left lateral decubitus position or, if immobilized on a long backboard, placing sufficient padding under the right side of the board to elevate it 30° or so. If hypotension does not correct with this measure, hemorrhagic shock should be suspected. Oxygen should be administered, and the patient transported to a facility that has both trauma and obstetrical capabilities.
An algorithm has been developed that details the indications for spinal immobilization in the prehospital setting (see Chapter 23) (Fig. 7-6).50,101 Patients with penetrating trauma to the torso almost never have an unstable vertebral column.102 A recent analysis of data from the National Trauma Data Bank showed that victims of penetrating trauma who received prehospital spinal immobilization had a higher risk of death compared to those who did not.103 Therefore, spinal immobilization is indicated in the setting of penetrating trauma only when the patient has a neurologic complaint or finding. In patients with blunt trauma, spinal immobilization should be performed if the patient has an altered level of consciousness (GCS score <15) or if spinal pain or tenderness, a neurologic deficit or complaint, or an anatomic deformity of the spine is present. In the absence of these findings, the mechanism of injury should be evaluated. If the mechanism is considered to be concerning, the patient should be evaluated for evidence of alcohol or drug intoxication, presence of a distracting injury, or the inability to communicate. If any of these are present, spinal immobilization should be performed. In their absence, spinal immobilization is not indicated.
Indications for spinal immobilization. (Reproduced with permission from Salomone JP, Pons PT, McSwain NE, eds. PHTLS: Prehospital Trauma Life Support. 7th ed. St. Louis: Mosby; 2011:257. Copyright © Elsevier.)
This is the only immediately life-threatening condition associated with trauma to an extremity (see Chapters 39, 40, 41). External hemorrhage should be controlled with direct pressure or a pressure dressing, followed by a tourniquet if these measures fail. Internal hemorrhage is best managed in the field by immobilization of the extremity. In the critically injured patient, immobilization to a long backboard is sufficient stabilization. If the patient does not have life-threatening injuries, time can be taken to splint each suspected fracture individually. A traction splint provides reasonable pain control and will stabilize a suspected fracture of the femur.
The ACSCOT has published guidelines for the management of amputated parts.104 These include the following:
Cleansing the amputated part by gentle rinsing with lactated Ringer’s solution.
Wrapping the part in sterile gauze moistened with lactated Ringer’s solution and placing it in a plastic bag.
Labeling the bag or container and placing it in an outer container filled with crushed ice.
The part should not be allowed to freeze, and it should be transported along with the patient to the closest appropriate facility.
In the prehospital setting, analgesics are indicated for an isolated injury to an extremity, but not in a patient with multisystem trauma.50,105 After appropriately splinting the extremity, small doses of narcotics titrated intravenously may help relieve pain. The patient should be observed for side effects including hypotension and respiratory depression. Narcotics should not be administered in the trauma patient who exhibits signs of shock or when the patient appears to be under the influence of drugs and alcohol.