Approximately 20 percent of all trauma patients sustain injury to their thorax. Thoracic injuries are often obvious on presentation as with penetrating trauma from gunshot wounds or stab wounds. Sequelae may also be easier to identify due to the presence of subcutaneous emphysema or sucking chest wounds. Alternatively, thoracic injury may be indolent in nature as in some cases of blunt trauma where signs of injury may be more subtle, presenting solely with tachypnea or tachycardia. Understanding the mechanism of injury can increase awareness of potential injuries and help direct the diagnostic evaluation. Physical examination is essential in determining injuries as part of your initial assessment.

Guidelines promoted by the Advanced Trauma Life Support (ATLS) course offered by the American College of Surgeons remain the best approach to the care of injured patients. Control of airway, breathing, and circulation is of paramount importance to the successful management of thoracic trauma. After ensuring adequate control of the airway, the entire chest should be exposed. Bilateral chest rise and fall should be observed. The lungs should be auscultated to assess breath sounds. The front, back, and both axillae should be evaluated for external signs of trauma. Other physical findings such as tracheal position, heart sounds, and jugular venous status should be noted. Electrocardiographic leads should be placed and the rhythm determined. A chest x-ray should be obtained. All of this is accomplished as part of the ATLS primary survey.

Several further diagnostic tests are routinely used in the workup of thoracic trauma. The selection of these tests is based on the clinical condition, the mechanism of injury, and the examiner’s suspicion of a particular injury. Ultrasound imaging is a simple and rapid method of identifying pericardial fluid and assessing cardiac wall motion,¹ and can be used to detect the presence of a pneumothorax.² In hemodynamically stable patients, thoracic computed tomography (CT), aortography, esophagography/esophagoscopy, and transesophageal ultrasound may also have a role in the diagnosis of thoracic injury. Ultimately, thoracotomy may be necessary for both diagnosis and therapy. It is important to note that patients with thoracic trauma frequently demonstrate multisystem trauma. The workup and therapy need to focus on addressing the most life-threatening injuries first, potentially not involving the thorax.

This chapter discusses the diagnosis and management of common thoracic injuries with a focus on the pathophysiologic perturbation that results from trauma. A structure-specific approach is presented (e.g., heart injury, lung injury, etc.), recognizing that injuries to multiple structures often occur simultaneously and need to be concomitantly managed.

The bony thorax comprises the sternum and manubrium anteriorly, a solid rib cage anterolaterally, and the vertebral column posteriorly. The upper thorax is also superficially covered by the scapulae posteriorly, and the clavicles are positioned along the anterior apices bilaterally. These structures combine to confer substantial protection to the underlying soft tissues. The vast majority of information regarding injuries to the bony thorax can be obtained from physical examination and the initial chest x-ray, followed by further radiographic imaging.

Injury to the rib cage can range from simple rib fractures to flail segments that can alter breathing mechanics. Simple rib fractures are generally well tolerated. In the absence of underlying pathology, the treatment consists of pain control, incentive spirometry (IS), and aggressive pulmonary toilet. However, multiple rib fractures pose a greater challenge with pain control and can result in major morbidity in the older trauma patient (Fig. 2-1).³ Morbidities include the need for intubation, development of pneumonia, and prolonged ventilator support. Mortality has been reported to be as high as 22 percent in elderly patients with multiple rib fractures.⁴ The risk of death for all ages increases with the number of rib fractures. A large study using the National Trauma Databank showed a significant break point for mortality when more than six ribs were fractured.⁵

In patients with multiple fractures, early epidural analgesia should be considered. High thoracic epidural analgesia has been shown to improve outcomes.⁶ The Eastern Association of the Surgery of Trauma Practice management guidelines for pain management in blunt thoracic trauma presents Level I recommendations that epidural anesthesia is effective and Level II recommendations that thoracic epidurals should be placed for patients >65 years with four or more rib fractures (when not contraindicated, a thoracic epidural should be used) and considered in younger patients with the same injuries.⁷

Vital capacity and IS can be used to determine if adequate pain control has been achieved. Morbidity and mortality improves if IS is ≥15 mL/kg while achieving adequate pain control. Appropriate analgesia allows the patient to better expand the lung. It also prevents significant atelectasis and helps the patient clear secretions, thereby reducing the risk of pneumonia. In addition to epidural and intercostal blocks, nonsteroidal anti-inflammatory drugs and opioid analgesics play an important role in obtaining adequate pain control.⁸

The location of rib fractures is very important in the workup of the multiply injured patient. Fracture of the upper ribs (first, second, and third) suggests that a significant force was transmitted to the thorax and consequently an increased risk of concomitant great vessel injury; fractures should heighten the suspicion for these injuries and guide diagnostic investigation accordingly. In stable patients, the investigation of choice to evaluate possible great vessel injury is a CT angiogram.⁹ Alternatively, fracture of the lower ribs (eighth, ninth, and tenth) should raise the suspicion of injury of solid abdominal organs.

A segment of chest wall that is fractured in multiple places, resulting in an area of the bony thorax that is “free” from rigid fixation, is termed a flail chest. Small flail segments may be tolerated with good analgesia. Posterior flail segments benefit from several natural points of fixation (such as the overlying scapula) and do not contribute to respiratory embarrassment. However, larger flail segments, especially those encountered anteriorly and laterally, may compromise pulmonary function by blunting the negative inspiratory force of spontaneous inspiration. The negative pressure of the descending diaphragm preferentially collapses the chest wall, preventing aeration of the lung. In these cases, the treatment is positive pressure ventilation (PPV) (pneumatic stabilization) until the chest wall mechanics improves. Often, oxygenation is additionally impaired by the underlying pulmonary contusion that nearly always accompanies such an injury. The underlying pulmonary contusion and the protracted recovery usually govern the length of time needed for mechanical ventilation.

Occasionally, the flail segment requires fixation to maintain the integrity of the chest wall to allow ventilation and healing and re-establish lung volume. In addition, some ribs, fractured inward, may pose a threat to intrathoracic structures from sharp edges. A number of commercial systems of plates (both flat and U-shaped) are available for this.

Common causes of thoracic spinal fractures include falling from a height, motor vehicle accidents, and penetrating trauma. The entire spinal column is inspected and palpated on secondary survey. Crepitus or tenderness found on examination, suspicion due to mechanism, or the inability to obtain an adequate examination due to other distracting injuries should prompt additional radiographic study. CT scans are the preferred imaging modality for the detection of spinal fractures due to the speed of acquisition and the increased sensitivity and specificity.¹⁰ Because of the mechanisms of injury, many of these patients routinely have CT scans of their chest, abdomen, and pelvis to diagnose injuries within the chest or abdomen. Reconstructions of the thoracic spine can be created from these CT scans, further increasing sensitivity of detection of spine fractures.¹¹

These CT reconstructions are helpful in determining if a fracture of the thoracic spine is stable or unstable. Fractures of the vertebral body or transverse process are common whereas unstable fractures are not. There have been several classification systems to describe unstable fractures. The most commonly used classification system was described by Denis et al.¹² This classification system divides the spine into three columns (anterior, posterior, and middle). Disruption of two of the three columns is definitive for an unstable fracture. Unstable fractures require spinal precautions and eventual fixation. Assessment of the spinal canal and injury of the cord often requires magnetic resonance imaging (MRI).

In penetrating trauma, there is no role for the administration of steroids for spinal cord injuries. However, in blunt trauma, the administration of steroids for patients with neurologic deficits is controversial.¹³ The basis for their administration was derived from a post hoc analysis of the data collected in the National Acute Spinal Cord Injury Study (NACIS).^14,15 This led to the following recommendations. A bolus of methylprednisolone should be administered within 8 h of injury at a dose of 30 mg/kg/h. If the diagnosis is made within 3 h of injury, the infusion of methylprednisolone should be continued for 23 h at a dose of 5.4 mg/kg/h. If the steroid is started between 3 and 8 h, the infusion should be maintained for 48 h.

However, the results from this post hoc analysis have not been able to be duplicated. In addition, other studies have shown harm from steroid administration.¹⁶ Higher rates of respiratory tract infections, sepsis, urinary tract infections, and wound site infections have been associated with the administration of methylprednisolone. Subsequent evidence-based reviews of the literature have also not shown a benefit.^17–19 The lack of sufficient evidence prompted the deletion of steroid administration for spinal cord injury from the 8th edition of the ATLS course.

Sternal fractures are most often treated conservatively and do require additional treatment (Fig. 2-2); however, the presence of a sternal fracture can be a strong indicator of severe force injury and should raise awareness for associated injuries, such as blunt aortic, cardiac, and pulmonary injury. Scapular fractures also rarely contribute to the life-threatening nature of chest trauma. Similar to sternal fractures, their presence is a strong indicator of severe force injury that should raise suspicion of simultaneous injury to the great vessels. The treatment is typically conservative, focused on pain management.

Pulmonary Contusion

Pulmonary contusion is common after mechanisms of injury that impart substantial kinetic energy to the thorax. In blunt trauma, pulmonary contusion results from the transmission of force across the bony thorax. Due to the elastic nature of immature bone, children may present with a large pulmonary contusion with little evidence of bony thoracic injury. Penetrating injury results in contusion from both the direct tissue lacerations (especially injury to peripheral pulmonary vasculature) and the dissipation of the kinetic energy of the missile.

Alveolar hemorrhage and pulmonary parenchymal destruction typically manifest themselves within hours of injury and usually resolve within approximately 7 days. Clinical symptoms, including respiratory distress with hypoxemia and hypercarbia, worsen for the first 24 to 48 h.²⁰ The diagnosis of pulmonary contusion is made by the combination of pulmonary dysfunction and radiographic findings (Fig. 2-3A). CT of the chest has been shown to be superior to plain film in identifying a pulmonary contusion (Fig. 2-3B) and may help predict the likelihood of pneumonia, acute respiratory distress syndrome (ARDS), or mechanical ventilation. The main goals of management are pain control, judicious fluid administration, careful hemodynamic monitoring, and aggressive pulmonary toilet. Older patients are particularly susceptible to complications following pulmonary contusion.²¹

Penetrating Lung Injury

The majority of patients with penetrating lung injury can be managed with tube thoracostomy alone.²² However, 20 percent of those that require thoracotomy will need some form of lung resection.²³ The extent of the lung resection has been shown to be an independent predictor of hospital mortality. The worst outcomes are seen with pneumonectomy.²⁴ The higher mortality has encouraged the development of techniques to facilitate rapid and minimal resections. These techniques have used staplers for nonanatomic lobectomy and tractotomy.

Stapled pulmonary tractotomy has been shown in several series to provide rapid and effective exposure to bleeding pulmonary parenchymal vessels and transected bronchi.²⁵ Unilateral lung isolation is required. This technique can be performed with either single- or double-lumen endotracheal intubations. Most traumas do not allow the luxury of time and stability that is required to place a double-lumen endotracheal tube. If the surgeon is working on the left chest, right mainstem placement of the tube effectively isolates the left lung from ventilation. Conversely, while working on the right chest, a bronchial blocker can be placed in the right bronchus to isolate the right side. These maneuvers may be of benefit if tolerated by the patient because of the reduced positive pressure to the injured lung.

Using a Duval lung clamp placed parallel to the tract of the bullet, the stapling device is positioned so that one of the arms is placed through the entrance and exit wounds of the lungs. When the stapler fires, the bullet tract is exposed fully, allowing the surgeon to directly suture bleeding vessels and transected bronchi (Figs. 2-4 and 2-5). Pulmonary tractotomy for hemorrhage has dramatically decreased the number of patients requiring anatomic resection for trauma.

An underappreciated and potentially devastating consequence of thoracotomy for ongoing thoracic bleeding is systemic air embolism. The typical trauma patient has depressed intravascular volumes from major ongoing hemorrhage. In addition, the pulmonary architecture is destroyed from the traumatic insult. Both of these circumstances in combination with PPV allow air to escape the small airways and enter the bronchial veins, ultimately leading to a systemic air embolism. While the contributing factors are unavoidable, a heightened sense of urgency and rapid transport to the operating room before intubation is advised. Decreasing the length of time of increased airway pressures prior to controlling ongoing pulmonary bleeding minimizes this risk. Furthermore, when the thorax is entered, occlusion of the pulmonary hilum with a vascular clamp or with the surgeon’s fingers can impede the continuous passage of air into the coronary, cerebral, and other systemic arteries.

Tracheobronchial Injuries

Tracheobronchial injury is uncommon, but immediately life threatening. The true incidence of tracheobronchial injuries is difficult to define since a large portion of these patients will die prior to arrival at a hospital due to the loss of their airway. Based on autopsy reports, it is estimated that 2.5 to 3.2 percent of patients who die as a result of trauma have associated tracheobronchial injuries.²⁶ More than 80 percent of tracheobronchial injuries are due to blunt trauma located within 2.5 cm of the carina.²⁷ Tracheobronchial injury can present with subcutaneous emphysema, pneumothorax, massive air leak after tube thoracostomy, or hemoptysis.

In addition to tracheobronchial injury, it is important to recognize the potential for other associated injuries. A delay in the diagnosis of these injuries can potentially affect the overall morbidity and mortality of these patients.²⁸ Blunt trauma is often associated with multisystem trauma involving not only the chest, but the head, abdomen, and bony structures. Cervical trauma of the airway frequently involve the esophagus, the recurrent laryngeal nerves, the cervical spine and spinal cord, the larynx, and the carotid arteries and jugular veins.²⁹

Immediate recognition and stabilization of airway injuries is the first priority in trauma. The diagnosis and management should proceed simultaneously. Patients with respiratory distress and the clinical suspicion of an airway injury should be intubated immediately, preferably with guidance of a flexible bronchoscope. In the unstable patient, you should proceed with direct laryngoscopy and oral intubation with in-line cervical stabilization. Intubation should be followed by diagnostic bronchoscopy. For a bronchial laceration, placement of the endotracheal tube into the uninjured side facilitates repair and improves oxygenation. The operative approach depends on the location of injury. Posterior tracheal injury is repaired via a right posterolateral thoracotomy. The anterior and superior aspects of the upper trachea are best approached via median sternotomy; the distal trachea, carina, and left mainstem through the right chest; and the distal left and right bronchi by their respective thoracotomies. Repair is performed with nonabsorbable sutures, with care taken to reapproximate the mucosa (Fig. 2-6).

Blunt Cardiac Injury

Blunt cardiac injury (BCI) occurs when an anterior force compresses the chest. The transmitted force and the compression of the heart between the sternum and anterior thoracic spine is the predominant mechanism for BCI. Other mechanisms such as sudden deceleration, where the heart moves freely and strikes the sternum, can also cause BCI. Both of these mechanisms are seen during motor vehicle accidents where an unrestrained driver is propelled forward into the steering wheel. The sudden deceleration of the body and the compression of the chest contuse the heart. Patients sustaining blunt cardiac trauma have been reported to develop cardiac complications, including pump failure, dysrhythmias, myocardial infarction, myocardial rupture, valvular dysfunction, pericarditis, and tamponade.³⁰

The true incidence of BCI remains unknown as there is no diagnostic gold standard. Often, the presence of a myocardial contusion is defined by the particular method employed to detect it rather than by the presence of cardiac complications. Electrocardiograms (ECG), cardiac enzymes, and echocardiogram have all been used to identify BCI. However, the lack of a clinical gold standard makes it difficult to consistently define and difficult to interpret the literature. Postmortem, BCI is seen as a well-demarcated hemorrhagic area of the anterior wall of the right ventricle.

Current consensus suggests that patients who present with a mechanism consistent for BCI should have an ECG. The most common dysrhythmia seen with BCI is sinus tachycardia or atrial fibrillation. Other findings include new bundle branch block, ST segment depressions, or ST segment elevations.³¹ If an abnormality is present on the ECG, the patient should be admitted for monitoring for 24 to 48 h. Hemodynamically unstable patients should have an echocardiogram performed.³² There remains controversy regarding cardiac enzymes. At present there are not enough data to recommend using cardiac enzymes for screening of BCI.

Penetrating Cardiac Injury

Penetrating cardiac trauma remains a highly lethal but potentially salvageable injury.³³ Approximately 90 percent of victims with penetrating cardiac wounds die before reaching the hospital.³⁴ Patients arriving at the trauma center with vital signs who receive a prompt diagnosis and surgical intervention have substantially better survival rates. Other factors predicting improved survival include stab wounds versus gunshot wounds, single-chamber versus multiple-chamber injury, and the location of thoracotomy (operating room vs. ED (emergency department)).^35,36 Death occurs as a result of cardiac tamponade or exsanguination. The diagnosis of cardiac injury should be entertained in any patients with a precordial penetrating wound. The term “cardiac box” has been used to describe an area of the trunk in which penetrating injuries risk injuring the heart. It is defined laterally by the midclavicular lines (MCLs), superiorly by the clavicles, and inferiorly by the costal margins.

The diagnosis of tamponade by physical examination can be challenging, since the classic triad of tamponade (hypotension, muffled heart tones, and jugular venous distension) is only present in one-third of patients presenting with the diagnosis and the busy, noisy trauma bay makes physical diagnosis difficult. The presence of penetrating chest trauma in a moribund patient is an indication to proceed with a median sternotomy or left anterolateral thoracotomy. In stable patients, the subxiphoid pericardial view, as part of the focused abdominal sonography for trauma or FAST, can aid in determining the diagnosis of tamponade.^37,38 An equivocal or positive FAST examination necessitates an operative pericardial window. The presence of hemothorax can confound the results of the FAST. The decompression of blood from the pericardial sac into the chest cavity can result in a false negative. In this subset of patients, it may be reasonable to proceed with a pericardial window irrespective of the FAST results. Pericardial windows can be accomplished through either a subxiphoid approach or a transdiaphragmatic approach. The transdiaphragmatic approach is useful if there are concurrent intra-abdominal injuries requiring laparotomy. Regardless of the approach, the chest should be prepped and draped in preparation for a sternotomy.