Management of Acute Trauma

Airway

Upon arrival of the patient to the trauma bay, the status of the airway should be immediately assessed. Simply eliciting a verbal response provides the most meaningful information, as the ability to speak usually indicates adequate airway protection. Patients who cannot speak have either mental status depression or some obstruction to air flow, both of which are indications for airway management. Further indicators of airway compromise include noisy breathing, severe facial trauma (specifically with oropharyngeal blood or foreign body), and patient agitation. A determination of the adequacy of the airway, as well as the decision to obtain improved airway control, should be completed within seconds of arrival. After the initial assessment, frequent reassessment for deterioration and the development of airway compromise is paramount.

Until it is ruled out with an appropriate evaluation, all injured patients should be assumed to have an injury to the vertebral column and have the appropriate precautions maintained. This is of significant importance during the manipulation of the head and neck while the airway is being managed. Cervical spine protection includes the use of a hard cervical collar and the maintenance of the log roll technique for all movement of the patient. During airway assessment and management, the anterior portion of the cervical collar can be removed to optimize exposure, but manual stabilization from an assistant should be provided when the collar is not securely in place. Rigid long spine boards may be of value during transport of the patient but should be removed as soon as possible to avoid pressure-related wounds that can occur within a short time.

When the airway is deemed inadequate, a definitive airway must be established. The definitive airway of choice for most injured patients remains oral endotracheal intubation provided by RSI or DAI (ATLS 10th edition ) technique. While the patient is being prepared for intubation, adjuncts such as oropharyngeal and nasopharyngeal airways may assist in maintaining airway patency during preoxygenation. The patient is provided a sedative and fast-acting neuromuscular blocker, such as succinylcholine or rocuronium, to enhance glottic visualization maximally. Direct laryngoscopy and endotracheal intubation are performed, with care taken to avoid cervical spine motion. The appropriate position of the tube in the trachea is confirmed by chest auscultation, end-tidal carbon dioxide measurement, and a chest radiograph. The presence of experienced airway personnel is critical and, particularly in trauma centers, is often an important component of the trauma alert system.

Common adjuncts in the difficult airway scenario include the gum elastic bougie, video-assisted laryngoscopy, and blind insertion airway device. When the normal view of the glottis is obscured, the bougie may be placed with a limited view of the vocal cords, assisting with appropriate placement the endotracheal tube. Although prior studies have suggested improvement in success rates of intubation with bougie, a recent systematic review and metaanalysis concluded that equivalent rates of first-attempt intubation, intubation duration, and esophageal intubation were observed with techniques incorporating either bougie or stylet. The authors further note that available studies comprising the analysis include small sample sizes and heterogeneous types of providers performing the procedure.

Several devices are now available that provide the clinician a view of the upper airway anatomy that is displayed on a video monitor. Despite this mitigation of challenges related to the angle of the airway, recent data have yielded conflicting results as to any improvement in successful first-pass orotracheal intubation. In parallel to the utility of the bougie, a device is only as functional as the provider employing it. Whichever adjunct, or combination thereof, is selected in the setting of a difficult airway, familiarity with benefits, risks, and limitations of the tool is upon the person performing the procedure.

The blind insertion airway device offers an additional instrument to be applied when attempts at orotracheal intubation are unsuccessful. Devices such as the laryngeal mask airway, multi-lumen esophageal airway (Combitube), and laryngeal tube airway (King LT-D) are placed blindly and function by occluding the esophagus and the posterior pharynx, allowing assisted ventilation to pass selectively down the trachea.

As airway specialists are transitioning to advanced techniques, preparation for a surgical airway should begin. Before physiologic deterioration, a cricothyroidotomy should be performed when other approaches have failed. The inability to maintain oxygenation with a bag valve mask between intubation attempts is a reasonable indication for establishment of a surgical airway. A cricothyroidotomy ( Fig. 17.5 ) is performed in a three-step maneuver:

• 1.

  Spreading retraction with the nondominant hand of the tissues overlying the cricothyroid space (typically performed from patient’s right side).

• 2.

  Keeping lateral tension on the tissues, vertically incise in the tracheal midline, beginning at the thyroid cartilage and extending inferior to the cricoid cartilage.

• 3.

  Transversely incising the cricothyroid membrane, which can be palpated between the thyroid cartilage and cricoid ring, followed by insertion of a 6-0 endotracheal tube or tracheostomy appliance.

It is critical that the surgeon frequently palpate the underlying structures to guide the dissection and avoid injury to more lateral structures of the neck. Care must be taken also to avoid advancing an endotracheal tube past the carina, which is common in these situations. Tube position is immediately confirmed with lung auscultation and end-tidal carbon dioxide determination. Finally, patients suspected of having a laryngeal injury may have abnormal anatomy in the vicinity of the cricothyroid membrane and therefore require a tracheostomy rather than a cricothyroidotomy.

Breathing

Following the management of the airway, breathing is evaluated by visualizing chest movement, auscultating breath sounds, and measuring oxygen saturation. Limited respiratory effort or dyspnea requires support of ventilation and further assessment of the chest. Ventilatory problems may be secondary to tension pneumothorax, massive hemothorax, or flail chest with pulmonary contusion. Tension pneumothorax may cause respiratory deterioration but may also be in the form of unstable hemodynamics or cardiovascular collapse. It is a clinical diagnosis that should be recognized on the primary survey without need for radiographic confirmation before treatment. Deviation of the trachea in the sternal notch with unilaterally absent or diminished breath sounds and cardiopulmonary compromise should immediately suggest tension pneumothorax. Thoracic decompression should be rapidly performed with a large-bore needle or tube thoracostomy, depending on the availability of equipment and supplies. Massive hemothorax also requires tube thoracostomy with evacuation of blood and reexpansion of the lung. Severe pulmonary contusion commonly requires aggressive mechanical ventilation, often with elevated levels of positive end-expiratory pressure. To avoid loss of positive end-expiratory pressure, one should resist repeated disconnection from the ventilator to suction or manually ventilate the patient, as oxygenation will only improve with an uninterrupted circuit.

Circulation

The primary goal of a cardiovascular assessment is determining the presence or absence of shock. ATLS defines shock clinically as evidence of end-organ hypoperfusion present on physical exam. Clinical signs of shock are demonstrated in Box 17.3 . Although hypotension is a clear indicator of cardiovascular decompensation, patients may be in shock well before the onset of hypotension, given physiologic compensatory mechanisms. By far, the most common cause of shock in the injured patient is hemorrhage, and acute blood loss must be ruled out before other causes are considered. Table 17.4 indicates the different classes of hemorrhagic shock.

Upon recognizing the presence of shock, ATLS recommends intravenous (IV) access with two large-bore, short, peripheral IV catheters, an intraosseous needle, or a central venous catheter and initial resuscitation with 1 L of warmed crystalloid solution. Patients who fail to respond appropriately to initial crystalloid resuscitation should undergo product-based resuscitation, recognizing that crystalloid resuscitation beyond 1.5 L increases risk of death.

The patient must next undergo a rapid screen to identify the cause of life-threatening blood loss. There are essentially five major locations through which exsanguination may occur: chest, abdomen, retroperitoneum, pelvis, and/or long bone fractures. The initial physical examination identifies sources of external blood loss and long bone fractures. These are managed immediately with direct pressure and fracture splinting, respectively. Adjunctive imaging to the primary survey includes x-ray examinations (i.e., chest and pelvis) and ultrasound. A chest film quickly evaluates for hemothorax and a pelvic film will identify pelvic fracture. The focused abdominal sonography in trauma (FAST) scan is a rapidly obtainable ultrasound examination that assesses for intraperitoneal fluid. Specifically, the FAST scan assesses the hepatorenal, splenorenal, and pelvic spaces for fluid, which is presumed to be blood in the setting of trauma. The value of the FAST scan is that it can be performed quickly in the trauma bay and rapidly repeated, if necessary. As an example, blood in the hepatorenal space on FAST scan is demonstrated by Fig. 17.6 .

After the initial administration of IV fluid, patients are assessed for ongoing signs of shock. Those who respond by demonstrating a normalizing physiologic state then undergo a comprehensive evaluation to identify all injuries. A common pitfall during this time is to continue administering IV fluids at a high rate that may mask ongoing blood loss. As mentioned previously, failure to respond to the initial crystalloid bolus likely indicates continued bleeding, necessitating immediate intervention. Ongoing intrathoracic bleeding after chest tube placement may require thoracotomy. Intraabdominal bleeding in the hemodynamically unstable patient warrants emergent laparotomy. Pelvic fractures require immediate management of any increased pelvic volume with a binder or sheet, followed by operative or angiographic treatment with embolization for arterial hemorrhage.

Disability and Exposure

During the primary survey, it is valuable to make a rapid determination of neurologic function. Of particular importance is globally characterizing neurologic function to assess for traumatic brain and spinal cord injuries (SCIs). The GCS score should be determined to identify deficits in eye opening, verbal ability, and motor responses to potentially reflect the degree of neurologic injury. When sedating medications are required, noting the baseline level of neurologic function before administration can be beneficial. The spinal cord is grossly assessed by visualizing movement of the extremities. While neurogenic shock should always be considered in the setting of hypotension with lack of extremity movement, the provider must be careful in attributing shock to an SCI due to the frequency of hemorrhage in the trauma patient. It is important to recognize that classic teaching requires a cervical or high thoracic spine injury to produce neurogenic shock. If a patient is able to move their upper extremities, the likelihood of neurogenic shock is greatly diminished.

All clothing is removed at this time to allow for an adequate examination, core body temperature measurement, and any required intervention. As hypothermia is one of the components in the “terrible triad of death” in trauma (coagulopathy, acidosis, hypothermia), efforts to restore physiologic body temperature with blankets, heating elements (i.e., Bair Hugger), elevated room/operating room (OR) temperature, and warmed resuscitative fluids are of critical importance.

Resuscitative Thoracotomy and Endovascular Aortic Occlusion

After critical injury, select patients who experience cardiac arrest may benefit from resuscitative thoracotomy (RT) in the emergency department. First formally described by Cooley and Debakey over 50 years ago for penetrating cardiovascular trauma, RT provides opportunity for four therapeutic maneuvers: release of cardiac tamponade, temporary repair of cardiac injury, cross-clamping the distal thoracic aorta, and management of intrathoracic bleeding. Given risks to health care providers performing the procedure and overall low rates of salvage, multiple studies have attempted to define what groups of patients should be candidates for the procedure on the basis of injury mechanism and physiology at the time of presentation. Patients with the best outcomes after RT are those with penetrating thoracic injuries and signs of life (reactive pupils, spontaneous ventilation, carotid pulse, measurable or palpable blood pressure, extremity movement, or cardiac electrical activity) upon reaching the emergency department. Seamon and colleagues reviewed 72 studies with 10,238 patients, concluding that patients presenting after penetrating chest mechanism, with and without signs of life, survived at 21.3% and 8.3%, respectively. By converse, blunt trauma patients presenting with and without signs of life reveals 4.6% and 0.7% survival from RT, respectively. Moreover, an NTDB review of 11,380 patients undergoing RT revealed a 100% mortality in both blunt and penetrating mechanisms for patients above the age of 57. In these circumstances, bilateral thoracostomy tubes with conservative transfusion measures are likely more appropriate. RT should only be performed in locations with readily available surgical support for definitive repair of thoracic injuries if return of spontaneous circulation is achieved.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has emerged over the past decade as a promising method of obtaining temporary hemorrhage control in the decompensating trauma patient. Although traditionally employed in the setting of abdominal aortic aneurysm repair, application for combat casualty care in noncompressible truncal hemorrhage was first described during the Korean War. With the evolution of this technology for rapid deployment in both military and civilian sectors, REBOA is now being used in approximately 51 domestic trauma centers (median 6 cases per center per year) in the setting of advanced shock and imminent cardiac arrest. Depending on the zone of trauma, REBOA is introduced through the common femoral artery, advanced proximal to level of injury, and inflated, effectively shunting blood to the heart and brain while also decreasing hemorrhage. Currently, there is no high-grade evidence to support indications or the superiority of REBOA beyond standard care, and a comparison of technique to RT introduces both survival and indication biases. Deployment of this technology should only take place within a trauma system capable of managing definitive surgical hemostasis and the multiple possible complications of placement (i.e., vascular injury, extremity ischemia, spinal cord ischemia). At present, protocols for utility are developed by multidisciplinary committee and may vary by institution.

Secondary Survey

ATLS defines the secondary survey as a thorough head-to-toe examination and patient history. This is often performed immediately after the primary survey in patients who are stable and not requiring emergent intervention. Findings identified during the secondary survey often prompt further evaluation with imaging or other diagnostic modalities. A more detailed neurologic evaluation can be completed at this time and abnormalities of the face and neck are identified. Posterior surfaces that are more difficult to visualize because of the cervical collar are now better examined. The torso is evaluated to identify evidence of pulmonary dysfunction, and findings consistent with peritonitis must be recognized. Seat belt marks or other superficial injury to the neck and abdomen may prompt further evaluation. The pelvis is assessed for tenderness and instability, with care taken to avoid excessive compression. A rectal examination with a nonbloody glove to assess the position of the prostate and the presence of gross gastrointestinal (GI) blood should be included. The extremities are manipulated to identify open or closed deformities and distal perfusion must be carefully assessed. Formal evaluation consisting of distal blood pressure measurements with comparison to uninjured extremities (i.e., ankle-brachial indices) is valuable to obviate further imaging for major vascular injuries. The patient is rolled to evaluate the spine for deformity or tenderness and the long spine board should be removed. In the setting of penetrating trauma, all possible areas of skin must be visualized, including those within body folds, scalp, posterior neck, mouth, axilla, perineum, and back. Marking of penetrating injuries with radiopaque markers can be extremely helpful if subsequent imaging studies are obtained.

Damage Control Principles

The concept of damage control arose in contrast to the traditional approach of definitive injury repair at index operation. It was noted that a portion of patients in the latter group would develop progressive intraoperative physiologic derangement with exacerbation of hypothermia, coagulopathy, and metabolic acidosis. Therefore, damage control emerged as a method of halting this rapid deterioration by expeditious hemostasis, including application of packs, management of GI contamination with repair or resection, and temporary abdominal closure. The patient was then transported to the intensive care unit, and definitive reconstruction could be delayed until resuscitation had been completed. Rotondo and associates first coined the term “damage control” to describe this approach to management in a series of 46 patients operated for penetrating abdominal injury. While actual survival rates were similar between damage control and definitive laparotomy groups (55% vs. 58%, respectively), a significant improvement in survival was noted in a subset of patients with major vascular injury and two or more visceral injuries (77% vs. 11%, P < 0.02). Although damage control began as a method to manage severe abdominal injuries, it is now universally used in the chest, pelvis, and extremities.

Functioning in tandem with damage control surgery, massive transfusion protocols (MTPs) have emerged from the military experience to reveal improved survival with transfusion of equivalent blood component ratios (1:1:1—plasma, platelets, PRBC) in order to approximate whole blood. This approach to the severely injured patient was termed damage control resuscitation and defined by permissive hypotension, facilitation of rapid hemostasis with early balanced transfusion, treatment of coagulopathy, and minimization of crystalloid. To inform initiation of MTP, the Assessment of Blood Consumption score provides a 4-point metric (penetrating mechanism, positive FAST, arrival systolic blood pressure 90 mm Hg, and arrival pulse >120 bpm) whereby clinicians may request product coolers based on prehospital (if available) or initial vital signs. A score of at least 2 was predictive of MTP need (75% sensitivity, 86% specificity) and a delay in initiation is associated with a 5% increase in mortality per minute. Many trauma centers have adopted this strategy and now have well-defined MTPs.

In certain locations, thromboelastography (TEG) provides adjunctive guidance to ongoing MTP and is rapidly obtainable as a point-of-care metric. Originally developed approximately 70 years ago for assessment of inherited bleeding disorders, TEG has historically been employed in liver transplant and cardiac surgery. In traditional analyzers, clot formation is assessed based on resistance transduced from a pin in a small quantity (360 μL) of whole blood. As the blood oscillates, a real-time graphic is produced, providing a dynamic representation of clot generation. Component deficiencies are illustrated as morphologic changes to the clot cylinder ( Fig. 17.7 ). Potential advantages to utilization of TEG-based resuscitation include rapid results for individualized component transfusion, overall conservation of blood products, and a survival benefit with fewer deaths due to hemorrhagic shock in the first 6 hours after injury.

Lastly, an additional treatment adjunct to MTP in damage control resuscitation is tranexamic acid (TXA). TXA is a synthetic derivative of lysine with high affinity for lysine binding sites on plasminogen, thus inhibiting fibrinolysis via antagonism of plasmin binding to fibrin surfaces. It has been shown previously to reduce the need for blood transfusion in elective surgery by one third. The Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage (CRASH)-2 trial randomized 20,211 injured patients to either early administration of TXA (within 8 hours) versus placebo. Patients who received TXA demonstrated a decrease in all-cause mortality compared with placebo (14.5% vs. 16%, P = 0.0035) and a reduction in risk of death due to bleeding (4.9% vs. 5.7%, P = 0.0077). Notably, there was no observed difference in rates of vascular occlusive events between the treatment and placebo groups (1.7% vs. 2.0%, respectively). While the study had limitations due to the inclusion of large numbers that did not require transfusion, it has led to TXA becoming a standard part of the initial resuscitation within many prehospital systems and trauma centers.

Injuries to the Brain

Even in the setting of optimal care, TBIs result in substantial morbidity and account for approximately one-third of all trauma-related mortality, resulting in an annual cost of $75 billion to the U.S. economy. Those who survive often experience permanent disability that ranges from mild deficits to conditions requiring permanent total care. Outcomes faced by patients who sustain polytrauma are often dictated predominantly by the TBI. As injury epidemiology has evolved, falls are now the most common cause of brain injuries, with those at the extremes of age being most vulnerable. Although further high-quality evidence for TBI is needed, comprehensive guidelines for management are described by the Brain Trauma Foundation, American College of Surgeons, EAST, and WTA.

At the tissue level, brain injuries are the result of either direct transmission of energy, the accumulation of blood within the cranium, or a combination of the two. Energy transmitted to the cranium and the underlying brain tissue can cause direct injury both at the location of contact and on the contralateral side (coup contrecoup). Further, the shearing of blood vessels at the time of injury can result in the accumulation of blood within the cranium. As is the case with most tissue, injured brain develops inflammation and edema after trauma that can be worsened by ongoing ischemia. According to the Monro-Kellie doctrine, any increase in the volume of intracranial contents (from extravascular blood or edema) results in an elevation of intracranial pressure (ICP) with an associated decrease in the volume of other tissues (i.e., brain parenchyma, intravascular blood, and cerebrospinal fluid [CSF]). As seen in Fig. 17.8 , an increase in intracranial volume ultimately results in an exponential increase in ICP, thereby worsening cerebral perfusion pressure (CPP), oxygenation, and increasing the risk of herniation.

In terms of specific TBI, epidural hematomas ( Fig. 17.9 ) typically result from a lateral fracture of the cranium, causing bleeding from the middle meningeal artery or a nearby vessel. Classically, the clinical course consists of an initial loss of consciousness followed by a lucid interval, during which time the hematoma expands. Upon reaching a significant size, the epidural hematoma causes profound neurologic deterioration. Recognition of this clinical course early may result in treatment with decompression, leading to a favorable outcome. Fortunately, the underlying brain tissue is often not severely injured in the setting of an epidural hematoma. This is in distinction to subdural hematomas, which commonly are associated with severe underlying brain tissue injury (see Fig. 17.9 ). Subdural hematomas are commonly caused by tearing of the bridging veins deep to the dura mater and superficial to the arachnoid mater. Although the hematoma itself can be compressive, it is usually the underlying contusion and axonal injury that predict the outcome after these injuries. Bleeding within the subarachnoid space is indicative of diffuse bleeding from brain tissue and in itself is not deleterious. Despite this, subarachnoid hemorrhages are not benign, and surveillance is mandated to identify deterioration. Parenchymal contusions of brain tissue result from the direct transmission of energy to the cranium and underlying brain as well as from movement of the brain within the rigid cranial vault, resulting in contrecoup injury. Finally, diffuse axonal injury describes the phenomenon of axonal disruption of from the neuronal body secondary to severe rotational forces. Imaging often underestimates the severity of diffuse axonal injury, revealing only punctate hemorrhages and loss of gray and white matter differentiation. Commonly, diffuse axonal injury becomes evident when patients demonstrate poor neurologic status in the setting of underwhelming imaging studies, although ultimate functional prognosis remains difficult to predict based on this finding.