INTRODUCTION — The presentation of penetrating thoracic trauma can vary widely, from stable patients with few complaints to hemodynamically unstable patients requiring immediate life-saving interventions. Even apparently stable patients with penetrating chest injuries can deteriorate precipitously and a focused evaluation must be rapidly performed to assess for life-threatening conditions.

This topic review will discuss the epidemiology, mechanisms, and general approach to the initial management of injuries sustained by adults with penetrating thoracic trauma. Blunt thoracic trauma, thoracic trauma in children, and definitive management of specific injuries are reviewed separately. (See "Initial evaluation and management of blunt thoracic trauma in adults" and "Thoracic trauma in children: Initial stabilization and evaluation".)

EPIDEMIOLOGY — Penetrating chest trauma is generally less common but more deadly than blunt chest trauma. According to small retrospective reviews, chest injuries are a relatively common cause of preventable death among trauma patients [1,2]. Thoracic wall penetration occurs most often from gunshots and stabbings, which comprise up to 10 and 9.5 percent, respectively, of all major trauma in the United States [3]. Other causes of penetrating thoracic injury include being impaled by objects as a result of industrial accidents, falls, collisions, blast injuries, and fragmenting military devices.

The incidence of penetrating thoracic trauma varies geographically. In the United States, 9 percent of all trauma related deaths occur from injuries to the thorax, of which one-third involve a penetrating mechanism [4,5]. In Europe, the incidence of penetrating trauma is reported to be as low as 4 percent [6]. However, in countries or regions engaged in warfare, up to 95 percent of military deaths may result from a penetrating mechanism [7]. Urban centers tend to have higher rates of interpersonal violence and a correspondingly higher percentage of injuries involve penetrating mechanisms compared to rural regions.

Most penetrating chest injuries do not require major operative intervention and many patients are managed with observation and serial evaluation using radiography or simple tube thoracostomy. Approximately 15 to 30 percent of penetrating thoracic injuries require surgery, as opposed to less than 10 percent of injuries from blunt chest trauma.

The exact incidence of specific wounds incurred from penetrating thoracic trauma is difficult to determine. Major vascular injuries occur in approximately 4 percent of patients with penetrating chest injuries. Penetrating tracheobronchial wounds are associated with concurrent esophageal and major vascular injures in approximately 30 percent of cases [8]. Cardiac injuries are sustained by 3 percent of patients with penetrating tracheobronchial wounds and are associated with high mortality.

The incidence of diaphragm injuries associated with penetrating trauma to the thoracoabdominal area is reported to be 11 to 19 percent [9-11]. This number increases to approximately 30 percent for stab wounds and 60 percent for gunshot wounds isolated to the left lower chest. Injuries to the diaphragm may be difficult to diagnose, as up to 31 percent of patients may demonstrate no abdominal tenderness and 40 percent may have normal chest radiographs. Among all asymptomatic patients with penetrating chest injuries, the risk of occult diaphragm injury is reported to be 7 percent [12]. If undiagnosed, diaphragm injury is associated with a high risk of bowel herniation. (See "Recognition and management of diaphragmatic injury in adults".)

ANATOMY, PATHOPHYSIOLOGY, AND MECHANISM — The thoracic structures at risk from penetrating chest trauma include the chest wall, lungs, tracheobronchial tree, heart, aorta and thoracic great vessels, esophagus, diaphragm, spinal cord, thoracic vertebrae, and the thoracic duct. Thoracic anatomy is reviewed separately; elements of particular relevance to penetrating trauma are discussed below. (See "Initial evaluation and management of blunt thoracic trauma in adults", section on 'Anatomy and mechanism'.)

Common mechanisms and associated injuries by location

●Chest wall – By definition, penetrating chest trauma violates the chest wall. However, depending upon the mechanism, penetrating trauma often causes less significant injury than blunt trauma. Low-energy mechanisms, such as stab wounds, rarely cause important injuries to the chest wall, with the exception of intercostal artery lacerations or single rib fractures. High-energy shotgun wounds can cause significant bony and soft tissue damage that may affect the stability of the chest wall leading to difficulties with ventilation. (See "Initial evaluation and management of chest wall trauma in adults".)

●Lungs – Lung injuries from penetrating trauma may include pneumothorax, pulmonary contusion, hemothorax, pulmonary laceration, or a combination thereof. Pneumothorax occurs in the great majority of patients with transpleural penetrating chest injuries. Pneumothorax is discussed in detail separately. (See "Thoracostomy tubes and catheters: Indications and tube selection in adults and children".)

Pulmonary contusion is a common injury after high-energy penetrating chest trauma [13]. Direct injury to the interstitium and alveoli occurs along the wound track. Hemorrhage within the lung parenchyma occurs at the time of trauma followed by interstitial edema, which usually begins within one to two hours and peaks at 24 hours following injury. Such hemorrhage may cause significant difficulties with oxygenation and ventilation. Occasionally, complications, such as abscesses or a bronchopleural fistula, can develop following penetrating chest trauma.

●Heart – Penetrating wounds of the heart often cause tamponade physiology or hemorrhagic shock, depending upon whether blood can escape the pericardial space. Due to the poor compliance of the pericardium, the acute accumulation of as little as 50 mL of blood can cause tamponade. The right ventricle is the most commonly injured chamber in penetrating trauma due to its anterior position within the chest cavity [14,15]. The next most common is the left ventricle. Atrial injuries are less common and generally less severe, while multi-chamber injuries cause higher mortality. (See "Cardiac tamponade".)

●Great vessels – Major vessels within the thorax include the aorta, the brachiocephalic trunk, and the left subclavian, left common carotid, and innominate arteries. Injuries to major vessels are rarely encountered in the emergency department because most patients with such wounds expire in the field [16]. However, vascular injury can present as massive hemothorax, necessitating immediate decompression and emergency operative intervention. (See "Overview of blunt and penetrating thoracic vascular injury in adults".)

●Tracheobronchial tree – Injuries to the tracheobronchial tree are less common in penetrating trauma than in blunt trauma and generally involve the cervical trachea [8]. These injuries often go unrecognized because early symptoms and signs of injury are nonspecific. Although complete transection of the trachea is usually diagnosed during initial evaluation, partial tears of the trachea and complete or partial tears of the bronchi may not be detected until the development of sequelae, such as tracheoesophageal fistula, mediastinitis, or empyema.

●Esophagus – Esophageal injuries can be difficult to detect. The uncommon nature of this injury, lack of specific clinical signs or chest radiographic findings, and the need for early diagnosis to avoid dangerous complications necessitate careful evaluation [17]. Further diagnostic testing of both the esophagus and tracheobronchial tree is needed for any penetrating trauma suspected to cross the mediastinum. (See "Overview of esophageal injury due to blunt or penetrating trauma in adults".)

●Diaphragm – Stab or gunshot wounds to the lower chest often entail injury of the diaphragm. The diaphragm can rise up to the level of the fourth intercostal space during exhalation and thus penetrating wounds of the thorax can involve intraabdominal organs as well. (See "Recognition and management of diaphragmatic injury in adults" and "Initial evaluation and management of abdominal gunshot wounds in adults" and "Initial evaluation and management of abdominal stab wounds in adults".)

General concepts about mechanism — The direction and extent of penetration from a stab wound is difficult to assess from the physical examination, and examination alone has poor sensitivity and specificity for identifying significant pathology, including pneumothorax and hemothorax [18]. Generally, a knife or other sharp object produces injury along its entry track and may damage any intrathoracic organ in its path. Although knowledge of the size and shape, as well as the angle and direction of the entrance, of the wounding instrument provides some guidance about potential injuries, the extent of internal injury from a seemingly small external wound can easily be underestimated. Of particular importance are penetrating wounds to “the box” because of the high risk of injury to the heart and other mediastinal structures [19]. The box is defined superiorly by the clavicles and sternal notch, laterally by the nipple line, and inferiorly by the costal margins.

Gunshot wounds and other higher velocity implements or debris have a less predictable pattern of injury. The trajectory of a missile may not follow a straight course. In addition, tissues can sustain damage not only from the direct path of the bullet, known as the permanent cavity, but also from the shock waves caused by the bullet, known as the temporary cavity. Temporary cavity wounds are caused by high velocity missiles. (See "Initial evaluation and management of abdominal gunshot wounds in adults", section on 'Mechanisms of injury'.)

PREHOSPITAL MANAGEMENT — Any patient with a penetrating chest injury, regardless of apparent stability, should be transported to the closest facility capable of caring for patients with major injuries. Patients with signs of shock or respiratory distress should be transported immediately. Scene time should be minimized and emergency life-saving interventions, such as tracheal intubation or needle decompression of a tension pneumothorax, are the only activities that may be permitted to delay transport [20]. Intravenous access and fluid resuscitation may be initiated while en route to the hospital [16,21]. Appropriate fluid resuscitation for trauma patients in the prehospital setting is discussed in detail separately. (See "Prehospital care of the adult trauma patient", section on 'Fluid resuscitation'.)

Patients with certain injuries from penetrating chest trauma may benefit from a select number of interventions performed in the field [22]. A "sucking" chest wound exists when air enters the pleural cavity preferentially via an open chest wound, rather than the lungs via the trachea. Placement of an occlusive dressing, taped on three sides, over a sucking chest wound can seal off air entry into the pleural cavity and prevent the expansion of a pneumothorax.

Evidence of a tension pneumothorax (eg, severe dyspnea with asymmetric breath sounds and hypotension) requires prehospital decompression with needle thoracostomy. Decompression appears to be successful more often when needle thoracostomy is performed in the fourth or fifth intercostal space using a longer needle (8 cm versus 5 cm) [23,24]. Advanced Trauma Life Support has adopted this approach in adults and recommends that chest decompression be performed at the fifth intercostal space in the midaxillary line, rather than the second intercostal space in the midclavicular line. However, in the prehospital environment, anterior placement may be preferred. Keys to successful performance of this important procedure are described separately. (See "Prehospital care of the adult trauma patient", section on 'Needle chest decompression'.)

Whether to maintain spinal precautions in patients suffering from penetrating trauma is a topic of debate. Isolated, low-energy, penetrating thoracic trauma is unlikely to create spinal instability and immobilization of the cervical spine may not be necessary in patients who are alert and free of neurologic deficits [25,26]. However, victims of penetrating trauma may also have sustained blunt trauma (eg, falling after being shot) and spinal precautions should generally be observed in patients with alterations in mental status or neurologic deficits. (See "Penetrating neck injuries: Initial evaluation and management", section on 'Cervical spine immobilization'.)

CLINICAL FINDINGS

Common signs of injury — Clinical findings in patients with penetrating chest trauma vary widely depending upon the structures injured, the extent of the injuries, concomitant injuries, and the patient’s body habitus and mental status.

The following symptoms and signs raise suspicion for significant underlying injury in patients who may not otherwise manifest specific or concerning findings:

●Any vital sign abnormality, especially hypotension, hypoxia, or persistent tachycardia, should raise suspicion for underlying injury. Young healthy patients or elders in shock may not present in typical fashion. (See "Initial management of NON-hemorrhagic shock in adult trauma" and "Geriatric trauma: Initial evaluation and management".)

●Persistent shortness of breath (SOB) or pleuritic chest pain suggests injury to the lungs or pericardium.

●A foreign body sensation in the throat or change in voice suggests tracheal or esophageal injury. (See "Penetrating neck injuries: Initial evaluation and management".)

●Diminished breath sounds strongly suggest pneumothorax but may not be appreciated if the pneumothorax is small or the environment is loud.

●Jugular venous distension suggests pericardial effusion. However, jugular veins may appear prominent in supine patients without an effusion. Conversely, distended veins may not be present in hypovolemic patients with tamponade.

●Subcutaneous air (crepitus) strongly suggests a tracheobronchial injury or a pneumothorax, either large or small. Both injuries must be considered.

Specific injuries

Pneumothorax — Pneumothorax should be suspected in any patient with penetrating chest trauma, although a small pneumothorax may be clinically undetectable. The severity of clinical findings even in patients with a significant pneumothorax varies and does not necessarily correlate with size (image 1). Unilateral diminished breath sounds strongly suggest pneumothorax, and subcutaneous air anywhere in the chest wall of a patient with penetrating thoracic trauma almost guarantees it. Hyperresonance is more common with tension pneumothorax and may be detectable with percussion.

Tension pneumothorax causes severe acute respiratory and cardiovascular distress. Symptoms and signs include dyspnea, agitation, tachycardia, hypotension, depressed mental status, diminished breath sounds, and in the absence of significant hemorrhage, jugular venous distension. With intubated patients, airway resistance increases and bag-mask ventilation becomes difficult [27].

Pulmonary contusion — Pulmonary contusion is a direct bruise of the lung, which causes alveolar hemorrhage and edema [28]. Clinical symptoms and signs of pulmonary contusion include dyspnea, hypoxia, tachypnea, and hemoptysis. The severity of these signs usually correlates with the extent of alveolar injury.

Radiographic findings associated with pulmonary contusion most often consist of patchy or diffuse areas of infiltrate, which may initially be subtle but worsen over 24 to 48 hours, especially in the setting of large volume fluid resuscitation [29]. Once infiltrates appear, crackles and rhonchi often become audible and clinical manifestations, such as dyspnea and hypoxia, worsen.

In most cases, significant force (ie, high-energy trauma) is required for a pulmonary contusion. In addition, high velocity gunshot wounds can cause clinically significant damage to the lung parenchyma.

Hemothorax — Patients with injuries to the great vessels rarely survive to reach the hospital. Survivors with a significant hemothorax have often sustained injuries to the lung parenchyma, or possibly intercostal blood vessels. Depending upon the size of the hemothorax, breath sounds are diminished and signs of shock may be present. Hemothorax often occurs concomitantly with pneumothorax and other injuries.

Pericardial tamponade — Any patient with a penetrating wound to the chest, back, neck, or abdomen can develop pericardial tamponade. If the rate of bleeding is slow or the pericardium periodically decompresses by emptying blood into the pleural space, patients may initially appear stable [27]. Some patients may complain of shortness of breath. Beck’s triad (hypotension, jugular venous distension (JVD), muffled heart sounds) can be difficult to detect and may not be present. In hypovolemic patients, JVD may be absent. Ultimately, tamponade physiology causes diminished cardiac output, leading to a decrease in systolic blood pressure and a narrowing of the pulse pressure. Diagnosis should be determined rapidly by ultrasound, if immediately available (waveform 1 and movie 1 and movie 2). (See 'Extended Focused Assessment with Sonography in Trauma' below and "Emergency ultrasound in adults with abdominal and thoracic trauma", section on 'Pericardial and limited cardiac examination'.)

Tracheobronchial injury — Lacerations of the trachea or bronchi allow air into the mediastinum, which can dissect into the soft tissues of the anterior neck (image 2 and image 3). This subcutaneous emphysema may be palpable. A crunching sound (Hamman sign (movie 3)) may be heard over the precordium, reflecting the presence of air in the mediastinum. Air may leak into the pleural space leading to symptoms and signs of a pneumothorax. Neck injuries involving the tracheobronchial tree and the esophagus are discussed separately. (See "Penetrating neck injuries: Initial evaluation and management".)

Esophageal injury — Esophageal injuries have no specific associated clinical signs and are notoriously difficult to diagnose, but patient mortality increases substantially when diagnosis is delayed [17]. Symptoms and signs may include painful swallowing, throat, neck, or chest pain, cough, hematemesis, difficulty breathing, and subcutaneous emphysema. Any patient with possible esophageal injury must be evaluated with advanced diagnostic imaging. (See 'Secondary survey' below and 'Chest computed tomography (CT)' below and 'Esophagoscopy and esophagography' below.)

INITIAL EVALUATION AND MANAGEMENT — Before beginning the primary survey, the patient’s appearance may provide the clinician with a clear sense of their condition. Respiratory distress, diaphoresis, combativeness, or an unwillingness to lie flat may signal active or imminent cardiopulmonary decompensation.

Rapid assessment of the patient with penetrating chest trauma is essential. The primary survey of Advanced Trauma Life Support provides a clear approach to the initial evaluation of the trauma patient organized according to the injuries that pose the most immediate threats to life. Many such injuries involve thoracic structures.

The primary survey is reviewed in detail separately; aspects of the survey of particular importance to penetrating thoracic trauma are discussed below. (See "Initial management of trauma in adults", section on 'Primary evaluation and management'.)

Airway — Assessment of the airway to determine its patency and the need for tracheal intubation is generally the first step of the primary survey [30]. However, immediate tracheal intubation of patients with pericardial tamponade or a tension pneumothorax can exacerbate hypotension and even cause cardiovascular collapse. This is due to the increased intrathoracic pressure caused by positive pressure ventilation, which reduces venous return. Therefore, whenever possible, evacuation of the pericardial effusion or decompression of the pneumothorax should be performed first, while the patient is prepared for intubation.

If time allows and resources are available, it is best to perform these procedures (including tracheal intubation) in the operating room, but this may not be possible in unstable patients. In addition, management will vary depending upon clinical circumstances. As examples, a patient with an isolated tension pneumothorax treated successfully with a chest tube may not need to go to the operating room while a patient with tamponade physiology will require surgical repair (eg, thoracotomy or pericardial window).

Airway management is discussed in detail separately. (See "Basic airway management in adults" and "Approach to advanced emergency airway management in adults" and "Rapid sequence intubation for adults outside the operating room".)

Breathing — Breathing assessment in penetrating chest trauma includes inspection of the chest wall for asymmetries in appearance or chest rise, auscultation of breath sounds, palpation of the chest wall for flail segments, step-off, and crepitus, and palpation of the trachea for any deviation from midline. In patients with a tension pneumothorax, asymmetric breath sounds, hypoxia, and hypotension are common; tracheal deviation is a late finding. Oxygenation is measured with a pulse oximeter and oxygen provided as necessary.

Although the sensitivity of physical examination for a large pneumothorax appears to be better, physical examination has not been shown to be sufficiently sensitive to rule out a pneumothorax or hemothorax from penetrating trauma [18,31,32].

If the clinician detects asymmetric breath sounds and the patient is hemodynamically unstable or shows signs of respiratory distress, a tension pneumothorax is assumed to be present and a thoracostomy (chest) tube is inserted immediately [30]. Needle decompression may be performed first if there is any delay in placing the chest tube.

A 28 to 32 French chest tube should be used for thoracostomy in the setting of penetrating trauma [33,34]. Available evidence for the use of small-bore catheters (eg, 14 French) to manage traumatic hemothoraces is of limited quality, and further research is required before changes to standard practice can be considered [35,36]. If few experienced trauma clinicians are present, the chest tube is placed prior to assessing the circulation; at trauma centers with multiple clinicians available, assessment and management of the airway, breathing, and circulation are often performed in parallel, under the direction of the team leader. (See "Initial management of trauma in adults", section on 'Trauma team' and "Thoracostomy tubes and catheters: Indications and tube selection in adults and children" and "Prehospital care of the adult trauma patient", section on 'Needle chest decompression'.)

Circulation — Check for diminished pulses and hypotension. Look for tension pneumothorax and cardiac tamponade in any patient with hypotension following penetrating thoracic trauma.

The best to approach to volume resuscitation in patients with isolated penetrating thoracic trauma remains uncertain. For patients with signs of hemorrhagic shock, fluid resuscitation with either isotonic saline or Lactated Ringer and transfusion with blood products is administered as necessary. Blood products should be given as soon as the need for transfusion is recognized. Diagnosis and treatment of shock in the adult trauma patient is discussed in detail separately. (See "Initial management of NON-hemorrhagic shock in adult trauma" and "Initial management of moderate to severe hemorrhage in the adult trauma patient".)

Low-volume resuscitation (or "permissive hypotension"), as part of a "damage-control resuscitation" approach to the critical trauma patient may offer a survival benefit over conventional resuscitation strategies for patients with significant hemorrhage from penetrating trauma. Low-volume resuscitation aims to use the minimum volume of fluid necessary to maintain organ perfusion and tissue oxygenation while preventing the dilution of clotting factors, hypothermia, and disruption of thrombus from excessive IV fluid. Young, otherwise healthy trauma patients with penetrating torso injuries and no evidence of head injury, being treated surgically at a major trauma center, are likely the best candidates for this approach. However, much remains uncertain about low-volume resuscitation and further research is needed. This approach is reviewed in greater detail separately. (See "Initial management of moderate to severe hemorrhage in the adult trauma patient", section on 'Delayed fluid resuscitation/controlled hypotension' and "Overview of damage control surgery and resuscitation in patients sustaining severe injury".)

Extended Focused Assessment with Sonography in Trauma — The Extended Focused Assessment with Sonography in Trauma (E-FAST) examination is an important part of the initial evaluation of patients with penetrating chest trauma. It accurately detects the presence of hemopericardium, pneumothorax, hemothorax, and peritoneal fluid, thereby helping to determine management priorities. A detailed description of how to perform E-FAST, and the clinical evidence supporting its use in penetrating thoracic trauma, are presented separately. (See "Emergency ultrasound in adults with abdominal and thoracic trauma".)

The pericardial ultrasound examination is performed first and identifies hemopericardium with high sensitivity, specificity and accuracy. However, there are case reports of false-negative examinations. These inaccurate examinations occur most commonly in patients with concurrent, large hemothoraces or mediastinal hemorrhage. To improve accuracy in such cases, we recommend that the pericardial ultrasound examination be repeated after the hemothorax is cleared by chest tube. False-negative examinations remain possible despite such maneuvers if the hemopericardium empties into the thoracic cavity, thereby preventing blood from accumulating in the pericardium. (See "Emergency ultrasound in adults with abdominal and thoracic trauma", section on 'Pericardial and limited cardiac examination'.)

An abdominal ultrasound examination showing intraperitoneal free fluid following thoracoabdominal trauma strongly suggests an intraabdominal injury, and in hemodynamically unstable patients assists in rapidly prioritizing operative interventions. (See "Emergency ultrasound in adults with abdominal and thoracic trauma", section on 'Abdominal examination'.)

Of note, in penetrating trauma, a negative E-FAST does not definitively exclude intra-abdominal wounds, such as a diaphragm or hollow viscous injury, and further evaluation with serial abdominal examinations, diagnostic peritoneal tap and lavage, computed tomography (CT), or exploratory surgery is required [37].

Thoracoabdominal trauma — Thoracoabdominal wounds present a diagnostic challenge as movement of the diaphragm makes it difficult to predict the tract of a penetrating injury [38]. If the wound is close to the upper abdomen, intraabdominal and diaphragmatic injuries must be considered and evaluated in addition to intrathoracic injury. Clinicians should consider the possibility of diaphragmatic and intra-abdominal injuries with all anterior penetrating wounds that lie inferior to the nipple line (fourth intercostal space) and posterior penetrating wounds inferior to the tip of the scapula (seventh intercostal space). Potential sites of intraabdominal injury include the liver, spleen, aorta and other great vessels. Diaphragmatic injury is often impossible to rule out solely on the basis of the physical examination. (See "Initial evaluation and management of abdominal stab wounds in adults" and "Initial evaluation and management of abdominal gunshot wounds in adults" and "Recognition and management of diaphragmatic injury in adults".)

Triage and transfer to a trauma center — Patients with symptoms or signs of significant injury following penetrating thoracic trauma should be transported directly to a trauma center whenever possible, rather than a community hospital. Retrospective studies suggest that mortality is reduced when severely injured patients are transported directly to a trauma center [39-43], and direct transport may be of relatively greater importance with penetrating thoracoabdominal injuries. However, field triage and transfer decisions may not be straightforward in some instances and the responsible clinician may need to consider such factors as the severity of injuries, local resources, and (particularly in rural areas) the distance and time necessary to complete the transfer to a trauma center [44,45].

Some patients with penetrating thoracic trauma will receive their initial care at community hospitals, possibly because they are initially asymptomatic. Indications for transfer to a higher level of care depend upon the needs of the patient and the capabilities of the clinicians and hospital [46]. In all cases, once the clinician determines that a trauma patient requires a higher level of care, transfer should be arranged as quickly as possible and should not be delayed for further diagnostic evaluations. Arranging transfer is sometimes difficult but rapid transport to a tertiary care hospital can be life-saving and must be anticipated.

The primary survey and initial interventions for life-threatening injuries of patients with penetrating chest trauma is no different at the community hospital, with the possible exception of emergency department (ED) thoracotomy. ED thoracotomy is not recommended if surgical back-up is not readily available. Appropriate airway management and resuscitation remain cornerstones of care. Patients meeting criteria for tube thoracostomy should have chest tubes placed prior to transfer and chest radiographs performed to confirm proper placement. Patients with ultrasound evidence of hemopericardium may benefit from pericardiocentesis and placement of a catheter that can be used to decompress the pericardium in case signs of tamponade develop during transport. (See 'Emergency department thoracotomy (EDT)' below and "Emergency pericardiocentesis".)

SECONDARY SURVEY — Definitive management of a hemodynamically unstable patient with penetrating thoracic trauma must not be delayed to perform a more detailed secondary evaluation. Such patients are taken directly to the operating room or angiography suite, or transferred to a major trauma center.

A careful, head-to-toe secondary assessment (ie, secondary survey) is performed in all trauma patients determined to be stable upon completion of the primary survey. The secondary survey is discussed in detail separately. (See "Initial management of trauma in adults", section on 'Secondary evaluation and management'.)

In patients with penetrating thoracic trauma, the clinician asks about symptoms, such as dyspnea, odynophagia, chest pain, and back pain, which may reflect a worsening pneumothorax, esophageal perforation, or tracheobronchial injury. Physical examination findings consistent with these injuries can include hematemesis, stridor, chest wall crepitus, and a crunching sound (Hamman sign (movie 3)) heard over the precordium, suggesting air in the mediastinum. Symptoms and signs of esophageal injury are nonspecific but may include chest pain, followed by fever, dyspnea, and chest wall crepitus. Chest wounds should be carefully examined for hematomas and air bubbling through the opening.

Care of the thoracic trauma patient does not end with the secondary survey. Continual reassessment of the primary survey and areas of potential injury is essential. Patients with penetrating thoracic trauma can deteriorate rapidly, and neither stable vital signs nor the absence of symptoms initially excludes the presence of a life-threatening injury. Continuous pulse oximetry monitoring is needed for patients with evidence of pulmonary injury, such as contusion or pneumothorax. In addition, if suspicion of pneumothorax or hemopericardium persists or increases, repeat bedside ultrasonography should be performed.

DIAGNOSTIC IMAGING

Chest radiograph — In general, a plain chest radiograph is obtained for all hemodynamically stable patients who present with penetrating chest trauma, whether or not they are experiencing signs or symptoms of intrathoracic injury. For stable patients, many recommend obtaining a posteroanterior (PA) film with the patient upright. With more severely injured patients, this approach is often impractical and possibly dangerous if spinal injuries are suspected. Supine anteroposterior (AP) films are generally obtained in such cases. Retrospective studies suggest that chest radiographs taken during expiration do not increase the sensitivity for detecting pneumothorax [47,48].

Up to 62 percent of civilian patients who are admitted with penetrating injuries to the chest are asymptomatic and have normal chest radiographs [49]. However, the initial chest radiograph shows variable sensitivity in detecting injuries, such as pneumothorax and hemothorax. Some studies report sensitivities for the detection of pneumothorax as low as 36 to 48 percent for supine AP films (image 1 and image 4) [50-52].

Injuries may not manifest initially. Early studies showed that 2 to 12 percent of initially asymptomatic patients with a normal AP chest radiograph at presentation are at risk for subsequently developing a pneumothorax or hemothorax. However, the negative predictive value of plain radiographs to diagnose these injuries increases to nearly 100 percent if repeated six hours after presentation [53]. Several small subsequent studies have found that a normal repeat upright PA chest radiograph performed at three hours is likely as sensitive as a repeat chest radiograph done at six hours [54-56].

Other important injuries may be detected on AP chest radiograph. Radiographic findings of pulmonary contusion range from patchy, irregular, alveolar infiltrates to frank consolidation. Usually these changes are present on the initial examination, but may worsen over the next several hours [28]. Cervical and mediastinal emphysema, alteration of the mediastinal contour, and left pleural effusion may be signs of esophageal injury. Rib fractures may also be identified. While not well studied, the straight left heart border sign (filling in of the left heart border inferior to the pulmonary artery) suggests the presence of hemopericardium after penetrating chest injury. In a study of 162 patients with penetrating chest trauma treated with a pericardial window, the sensitivity of this sign was 40 percent and the specificity 84 percent [57].

Thoracic ultrasound — We recommend that an ultrasound examination of the chest (E-FAST) be performed in all patients with penetrating chest trauma who do not proceed immediately to the operating room upon arrival. Ultrasound is easily portable, immediately available, and non-invasive. Overall, ultrasound appears to have superior sensitivity and similar specificity to supine AP chest radiography for the identification of pneumothorax in adults. Of note, the size and location of a pneumothorax affects ultrasound’s accuracy (as is the case with plain radiographs); small apical and medial pneumothoraces are more difficult to detect.

Detection of pneumothorax is based on the absence of pleural sliding and comet tail artifacts. The presence of pleural sliding excludes the diagnosis of pneumothorax at that location on the chest wall. Performance of the ultrasound examination in the setting of thoracic trauma and the ultrasound findings associated with the presence of a pneumothorax are discussed in greater detail separately. (See "Emergency ultrasound in adults with abdominal and thoracic trauma", section on 'Pleural examination'.)

Echocardiography — When the heart can be clearly visualized (eg, hemothorax does not obscure the image), the sensitivity of the cardiac portion of the FAST examination for identifying hemopericardium after penetrating chest trauma is reported to be as high as 100 percent [58,59], decreasing the need to obtain formal echocardiography. However, if the FAST examination cannot be performed or is inadequate because the heart cannot be well visualized or findings are ambiguous, formal transthoracic echocardiography should be performed if there is any concern for cardiac injury.

Chest computed tomography (CT) — Indications for obtaining a chest CT in a hemodynamically stable patient with penetrating thoracic trauma include the following:

●Trajectory of a penetrating object crosses the mediastinum or middle of the chest.

●Symptoms or signs concerning for esophageal or tracheobronchial or vascular injury are present. (See 'Clinical findings' above.)

●Chest pain, shortness of breath, or other symptoms consistent with injury are present that are not explained adequately by a plain chest radiograph.

These indications are not exhaustive and if there is clinical suspicion for a thoracic injury on other grounds it is reasonable to obtain a CT. CT of the chest demonstrates the greatest sensitivity and specificity for detecting pneumothorax and hemothorax, and most studies of ultrasound and chest radiographs use CT as the gold standard. However, CT exposes the patient to higher levels of radiation and may not be necessary if initial and follow-up plain chest radiographs are normal and there is no clinical suspicion for aortic or other major thoracic injury.

Overcrowded emergency departments are common, causing some patients to leave before repeat chest radiographs are obtained. Thus, some centers choose to perform an initial chest CT rather than plain chest radiographs to rule out pneumothorax and hemothorax, thereby ensuring the absence of gross injury and expediting disposition [60]. However, in the young, low-risk patient, this approach may be harder to justify when both cost and radiation risks are considered.

Any patient with a knife or gunshot wound that traverses the mediastinum should be evaluated with a chest CT. Injuries to a number of vital structures, including the heart, great vessels, esophagus, and trachea, can be missed on plain chest radiograph [61-63]. If CT reveals that the wound track does not traverse the mediastinum or travel close to vital structures, additional diagnostic imaging, such as angiography, echocardiography, and esophagoscopy, may be unnecessary [61,62].

Direct visualization of the tracheobronchial tree with bronchoscopy and evaluation of the esophagus with either esophagoscopy or a contrast esophagogram is necessary for any trajectory that passes close to mediastinal structures. Esophageal injuries in particular have a high incidence of morbidity and mortality when surgical repair is delayed, making early diagnosis imperative. (See 'Bronchoscopy' below and 'Esophagoscopy and esophagography' below.)

Some experts claim that a single non-contrast chest CT is preferable to serial chest radiographs in penetrating thoracic trauma for the exclusion of pneumothorax or other thoracic injury requiring intervention [64]. A normal non-contrast chest CT allows for expedited discharge, relieving overcrowded emergency departments, and may reduce costs [60]. According to a ten-year retrospective review from a single, level one trauma center, CT detected injuries not identified by plain chest radiograph in up to one-third of patients, but of the 42 patients found with such injuries, only 16 required significant intervention (tube thoracostomy in 14 and surgery for hemopericardium in 2) [65]. While CT is not the screening test of choice for pericardial effusions, especially in a symptomatic patient, one retrospective study reported that CT detected all four effusions present among the 60 patients with penetrating chest trauma who were evaluated [66].

CT is useful for excluding intraabdominal injury in hemodynamically stable patients with thoracoabdominal wounds. The trajectory of many penetrating injuries is difficult to assess by examination, and evaluation of the diaphragm, stomach, intestines, and solid organs using abdominal CT is often necessary. In a small study of hemodynamically stable patients, clinicians inserted sterile sponges soaked with Betadine or Visipaque into the tracts of posterior or flank stab wounds to improve wound visualization on CT [67]. Although effective in this small sample, further study of this technique is needed.

Multidetector CT (MDCT) is a useful method for evaluating the diaphragm in patients with penetrating trauma, provided the entire contour of the diaphragm is visualized and not obscured by artifact, effusion, or bone fragments. If high quality images obtained with a MDCT suggest the presence of diaphragmatic injury, further evaluation is warranted. (See "Recognition and management of diaphragmatic injury in adults", section on 'Computed tomography'.)

Preliminary retrospective studies suggest that CT esophagography is sensitive and specific for identifying penetrating esophageal and hypopharyngeal injuries [68]. However, given the limitations of these small studies and morbidity and mortality associated with missed esophageal injury, confirmation of such injuries with esophagography remains the preferred approach at many trauma centers.

Esophagoscopy and esophagography — An esophagram is usually performed in any patient with transmediastinal injuries or possible injury of the esophagus. Some centers perform a contrast esophagram with water-soluble contrast first and, if that study is negative, then repeat the study using barium sulfate contrast [69]. Other centers recommend a single contrast esophagram with barium rather than water-soluble contrast for increased sensitivity, superior image quality, and decreased risk of aspiration [70,71]. Flexible esophagogastroduodenoscopy (EGD) is an alternative approach but is generally less favored in the acute trauma setting because of the risk of causing additional injury, including pneumothorax. Whichever approach is used, rapid diagnostic evaluation is important because morbidity is reduced and the best surgical results are obtained when the time between injury and repair is minimized [72].

Bronchoscopy — Bronchoscopy is the diagnostic modality of choice to confirm injuries to the tracheobronchial tree. Early diagnosis is essential to reduce morbidity and obtain a successful primary reanastomosis [73].

DISPOSITION AND DEFINITIVE MANAGEMENT

Asymptomatic patient — Asymptomatic patients with penetrating thoracic injuries and a normal chest radiograph and eFAST ultrasound examination at presentation are observed for development of a delayed pneumothorax or hemothorax. A repeat examination and chest radiograph should be performed six hours after arrival. If the reevaluation is unremarkable, the patient can be discharged from the emergency department (ED), with instructions to return immediately should any concerning symptoms (eg, increasing shortness of breath, painful swallowing) develop.

While this is not our approach, some centers shorten the observation time and repeat the chest radiograph at three hours post injury based upon the results of small retrospective studies [54-56], while others perform initial noncontrast chest computed tomography (CT) to expedite patient disposition [60].

Patient with isolated pneumothorax or hemothorax — Pneumothorax is the most common serious injury associated with penetrating thoracic trauma and tube thoracostomy (ie, chest tube) is the most common intervention needed for treatment [74]. A chest tube alone is sufficient to manage 85 percent of cases.

Tube thoracostomy is needed for any patient with a pneumothorax who has chest pain, dyspnea, or hypoxia. Among asymptomatic patients, a chest tube is needed for any pneumothorax that occupies over 15 percent of the lung’s total volume, as these are not likely to resolve spontaneously.

Hemothoraces of volumes greater than 300 to 500 mL are treated with tube thoracostomy (28 to 32 French chest tube). A volume of 300 mL is needed for hemothorax to manifest on an upright chest radiograph. Large hemothoraces that remain undrained can compromise ventilation and may not resorb, and this unresorbed blood can eventually lead to infection and pulmonary fibrosis.

Immediate bloody drainage of ≥20 mL/kg (approximately 1500 mL) is generally considered an indication for surgical thoracotomy. Shock and persistent, substantial bleeding (generally >3 mL/kg/hour) are additional indications. Vital signs, fluid resuscitation requirements, and concomitant injuries are considered when determining the need for thoracotomy.

Occult pneumothorax — The management of occult pneumothorax, defined as a pneumothorax observed on CT but not visible on a plain chest radiograph, is discussed separately. (See "Initial evaluation and management of blunt thoracic trauma in adults", section on 'Occult pneumothorax'.)

Indications for operative management — Approximately 15 percent of patients with penetrating thoracic trauma require surgical management. Indications for urgent thoracotomy include cardiac tamponade and significant hemorrhage or a persistent air leak from a chest tube.

The presence of cardiac tamponade, most often identified by ultrasound during the FAST examination, mandates intervention with a pericardial window or median sternotomy. For hemodynamically unstable patients, emergency pericardiocentesis and placement of a catheter may be needed (see "Emergency pericardiocentesis"). However, pericardiocentesis cannot be relied upon for definitive diagnosis and provides only temporary pericardial decompression when a thoracotomy cannot be performed promptly. However, pericardial drainage in the emergency department is a reasonable option when surgery is not immediately available and the patient is hypotensive or otherwise appears hemodynamically unstable.

The drainage of massive amounts of blood upon placement of a chest tube indicates the presence of a major vascular injury that is unlikely to stop without surgical intervention. Many authors use 1500 mL of immediate chest tube drainage as the threshold for surgical thoracotomy, but others use 1000 mL [75]. Some authorities use 20 mL/kg as the surgical threshold. Ongoing bleeding at a rate of 200 to 300 mL/hour is another common indication for chest exploration [76,77].

Massive air leak is an indication for surgical exploration of the chest after penetrating injury. Massive air leak is defined as one present during all phases of respiration and preventing full expansion of the affected lung or impairing ventilation through diminished tidal volume [75]. These findings suggest major tracheobronchial injury that is unlikely to heal without surgical repair.

EMERGENCY DEPARTMENT THORACOTOMY (EDT)

Overview and survival — Emergency thoracotomy is performed to resuscitate trauma patients who have just sustained or are on the verge of cardiac arrest. A left anterolateral thoracotomy enables knowledgeable clinicians to perform several potentially life-saving maneuvers, including pericardotomy to decompress pericardial tamponade, temporary repair of penetrating myocardial wounds, cross-clamping of the descending thoracic aorta (thereby preventing exsanguinating hemorrhage in the abdomen and increasing perfusion of the brain and heart), and open cardiac massage. The performance of EDT is discussed separately. (See "Resuscitative thoracotomy: Technique".)

The effectiveness of EDT varies widely depending upon the location and mechanism of injury and whether signs of life were present upon arrival at the hospital [78-81]. According to multiple systematic reviews involving many thousands of cases of EDT performed at multiple institutions over approximately 30 years, survival following EDT is greatest among patients with isolated stab wounds to the heart who show signs of life at presentation [78,79,82]. Conversely, survival is rare among blunt trauma victims without signs of life upon arrival or patients with multiple gunshot wounds to the chest [83-85].

When analyzed by recognized factors of clinical importance, survival rates following EDT are as follows [78]:

●Mechanism of injury:

•Stab wound – 16.8 percent

•Gunshot wound – 4.3 percent

•Blunt trauma – 1.4 percent

●Location of injury:

•Thoracic injuries – 10.7 percent

•Abdominal injuries – 4.5 percent

•Multiple injuries – 0.7 percent

●Signs of life:

•Signs of life in the hospital – 11.5 percent

•Signs of life during transport – 8.9 percent

but not in the hospital

•No signs of life in the field – 1.2 percent

Survival data from a subsequent review performed by the Eastern Association for the Surgery of Trauma (EAST), including neurologically-intact survival, is summarized in the accompanying table (table 1).

Indications — EDT entails risk [86]. Transmission of communicable diseases, such as HIV and hepatitis, can occur; multiple sharp instruments, suture needles, and open rib fractures can cause iatrogenic injury. In addition, patients receiving EDT require many resources, diverting care from other patients in frequently over-burdened trauma centers. Given the resources required and risks entailed in EDT, we strongly recommend that hospitals develop policies to determine the circumstances under which the procedure is to be performed.

We believe that EDT is justified if the following conditions are met:

●Patient manifests signs of life in the field or the hospital, AND

●Patient has penetrating thoracic trauma and is hemodynamically unstable despite appropriate fluid resuscitation OR has not been pulseless for longer than 15 minutes, AND

●A thoracic or trauma surgeon is available within approximately 45 minutes

Signs of life that justify the performance of EDT include: spontaneous breathing, palpable carotid pulse, measurable blood pressure, electrical cardiac activity, pupillary response to light, and spontaneous extremity movement [79,87].

We believe that EDT is futile in the following circumstances:

●Patient has no pulse or blood pressure in the field

●Asystole is the presenting rhythm, and there is no pericardial tamponade

●Prolonged pulselessness (over 15 minutes) occurs at any time

●Massive, nonsurvivable injuries have occurred

●No thoracic or trauma surgeon is available within approximately 45 minutes

This approach is largely consistent with major society practice guidelines, which are described below [79,80,82]. In addition, we agree with the general warning expressed in guidelines from the Western Trauma Association that hospital-based physicians must be cautious about prematurely abandoning resuscitation efforts based upon prehospital assessment [80]. Ultrasound is a useful tool for helping to determine when the risks and resource burdens of EDT may be justified by helping to identify likely survivors [88].

The time frame in which a surgeon should be available following EDT is an approximation and not based upon any clear evidence or published guidelines. Given the logistics of community emergency medicine practice, 45 minutes seems to be a reasonable period. However, the appropriate time frame varies depending upon physician judgement and clinical circumstances. As examples, a longer period might be appropriate in the case of an isolated stab wound to the right atrium where bleeding is rapidly controlled and blood pressure maintained or when abdominal bleeding is well controlled by cross-clamping of the aorta and intermittent release of the clamp every 10 to 30 minutes is performed to reduce the risk of spinal cord ischemia and permanent injury while awaiting the surgeon's arrival.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is being investigated as a possible alternative to EDT in some trauma patients, possibly including blunt thoracic trauma. (See "Endovascular methods for aortic control in trauma".)

Guidelines from trauma organizations — The appropriate indications for emergency resuscitative thoracotomy continue to be debated in the literature, and several practice guidelines have been published, including ones from the American College of Surgeons Committee on Trauma (ACS-COT), the Western Trauma Association (WTA), and the Eastern Association for the Surgery of Trauma (EAST), which are summarized below.

Practice Management Guidelines published by the American College of Surgeons Committee on Trauma (ACS-COT) include the following recommendations [79]:

●EDT is best applied to patients sustaining penetrating cardiac injuries who arrive at trauma centers after a short scene and transport time with witnessed or objectively measured physiologic parameters showing signs of life.

●EDT should be performed in patients sustaining penetrating noncardiac thoracic injuries, but these patients generally experience a low survival rate. Because it is difficult to ascertain whether the injuries are noncardiac thoracic versus cardiac, EDT can be used to establish the diagnosis.

●EDT should be performed rarely in the patient sustaining cardiopulmonary arrest secondary to blunt trauma because of its very low survival rate and poor neurologic outcomes. It should be limited to patients who arrive with vital signs at the trauma center and experience witnessed cardiac arrest.

●EDT should be performed in patients sustaining exsanguinating abdominal vascular injuries, but these patients generally experience a low survival rate.

Practice Management Guidelines published by the Western Trauma Association include the following recommendations for EDT, referred to as Resuscitative Thoracotomy (RT) in these guidelines [80]:

●Patients undergoing cardiopulmonary resuscitation (CPR) on arrival to the hospital should be stratified based on injury and transport time.

●Indications for RT include the following:

•Blunt trauma patients with less than 10 minutes of prehospital CPR

•Penetrating torso trauma patients with less than 15 minutes of CPR

•Patients with penetrating trauma to the neck or extremity with less than 5 minutes of prehospital CPR

•Patients in profound refractory shock.

●Immediately following RT, the patient's intrinsic cardiac activity is evaluated; patients in asystole without cardiac tamponade are declared dead.

The Eastern Association for the Surgery of Trauma attempted to use the GRADE methodology to formulate recommendations for the appropriate use of EDT, including the following [82]:

●A strong recommendation that patients who present pulseless with signs of life after penetrating thoracic injury undergo EDT.

●A conditional recommendation for EDT in patients who present pulseless and have absent signs of life after penetrating thoracic injury, present or absent signs of life after penetrating extra-thoracic injury, or present signs of life after blunt injury.

●A conditional recommendation against EDT for pulseless patients without sign of life after blunt injury.

OUTCOMES — Overall mortality for severe penetrating thoracic trauma is high. However, among patients who survive to hospital admission, mortality is approximately 5 to 6 percent [89]. Outcomes correlate with the extent of injury and timeliness of treatment. Patients who are hemodynamically stable at presentation generally recover well with appropriate management.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: General issues of trauma management in adults" and "Society guideline links: Thoracic trauma" and "Society guideline links: Thoracic and lumbar spine injury in adults".)

SUMMARY AND RECOMMENDATIONS

●The presentation of penetrating thoracic trauma can vary widely, from stable patients with few complaints to hemodynamically unstable patients requiring immediate life-saving interventions. The thoracic structures at risk from penetrating chest trauma include the chest wall (including intercostal neurovascular bundles), lungs, tracheobronchial tree, heart, aorta and thoracic great vessels, esophagus, diaphragm, spinal cord, thoracic vertebrae, and the thoracic duct. (See 'Anatomy, pathophysiology, and mechanism' above.)

●Clinical findings in patients with penetrating chest trauma vary widely depending upon the structures injured, the extent of the injuries, concomitant injuries, and the patient’s body habitus and mental status. Symptoms and signs consistent with significant underlying injury include abnormal vital signs, persistent dyspnea, pleuritic chest pain, foreign body sensation in the throat or change in voice, diminished breath sounds, jugular venous distension, and subcutaneous air. Clinical findings associated with common injuries are described in the text. (See 'Clinical findings' above.)

●Rapid assessment of the patient with penetrating chest trauma is essential. The primary survey of the adult trauma patient is reviewed in detail separately; aspects of the survey of particular importance to penetrating thoracic trauma are discussed in the text. (See "Initial management of trauma in adults", section on 'Primary evaluation and management' and 'Initial evaluation and management' above.)

●Immediate tracheal intubation of patients with pericardial tamponade or a tension pneumothorax can exacerbate hypotension and even cause cardiovascular collapse. Therefore, whenever possible, evacuation of the pericardial effusion or decompression of the pneumothorax should be performed first, while the patient is prepared for intubation. (See 'Airway' above.)

●The best approach to volume resuscitation in patients with isolated penetrating thoracic trauma remains uncertain. Blood products should be given as soon as the need for transfusion is recognized. Low-volume resuscitation or permissive hypotension may offer a survival benefit. (See "Initial management of moderate to severe hemorrhage in the adult trauma patient".)

●Imaging studies used to evaluate patients with penetrating thoracic trauma are reviewed in the text. Ultrasound (E-FAST examination) and plain chest radiography are performed in nearly all cases that do not require immediate transfer to the operating room. A chest CT is performed if there is concern for esophageal, tracheobronchial, or vascular injury. (See 'Diagnostic imaging' above.)

●Patients with penetrating chest trauma who have just sustained or are on the verge of cardiac arrest in the emergency department may benefit from emergency thoracotomy. The indications, contraindications, and utility of emergency thoracotomy are reviewed in the text. (See 'Emergency department thoracotomy (EDT)' above.)

●Continual reassessment of the primary survey and areas of potential injury is essential. Patients with penetrating thoracic trauma can deteriorate rapidly, and neither stable vital signs nor the absence of symptoms initially exclude the presence of a life-threatening injury. (See 'Disposition and definitive management' above and 'Outcomes' above.)