Blunt Chest Trauma

Updated: Nov 10, 2022
Author: Mary C Mancini, MD, PhD, MMM; Chief Editor: John Geibel, MD, MSc, DSc, AGAF 

Overview

Practice Essentials

Trauma is the leading cause of death, morbidity, hospitalization, and disability in Americans from the age of 1 year to the middle of the fifth decade of life. As such, it constitutes a major health care problem. According to the Centers for Disease Control and Prevention (CDC), 200,955 deaths occurred from unintentional injury in 2020.[1]  

In particular, chest trauma is a significant source of morbidity and mortality in the United States. This article focuses on chest trauma caused by blunt mechanisms. Penetrating thoracic injuries are addressed in Penetrating Chest Trauma.

Blunt injury to the chest can affect any one or all components of the chest wall and thoracic cavity.[2] These components include the bony skeleton (ribs, clavicles, scapulae, and sternum), the lungs and pleurae, the tracheobronchial tree, the esophagus, the heart, the great vessels of the chest, and the diaphragm. In this article, each particular injury and injury pattern resulting from blunt mechanisms is discussed. The pathophysiology of these injuries is elucidated, and diagnostic and treatment measures are outlined.

Operative intervention is rarely necessary in blunt thoracic injuries. Most such injuries can be treated with supportive measures and simple interventional procedures such as tube thoracostomy.

Future directions for improving the diagnosis and management of blunt thoracic trauma involve diagnostic testing, endovascular techniques, and patient selection, as follows:

  • The use of thoracoscopy for the diagnosis and management of thoracic injuries will increase; the use of ultrasonography (US) for the diagnosis of conditions such as hemothorax and cardiac tamponade will become more widespread; spiral (helical) computed tomography (CT) techniques will be used more frequently for definitive diagnosis of major vascular lesions (eg, injuries to the thoracic aorta and its branches)
  • Endovascular techniques for the repair of great-vessel injuries will be developed further and applied more frequently
  • Patient selection and nonsurgical therapies for delayed operative management of thoracic aortic rupture will be refined

Anatomy

The thorax is bordered superiorly by the thoracic inlet, just cephalad to the clavicles. The major arterial blood supply to and the venous drainage from the head and neck pass through the thoracic inlet.

The thoracic outlets form the superolateral borders of the thorax and transmit branches of the thoracic great vessels that supply blood to the upper extremities. The nerves that make up the brachial plexus also access the upper extremities via the thoracic outlet. The veins that drain the arm (of which the most important is the axillary vein) empty into the subclavian vein, which returns to the chest via the thoracic outlet.

Inferiorly, the pleural cavities are separated from the peritoneal cavity by the hemidiaphragms. Communication routes between the thorax and abdomen are supplied by the diaphragmatic hiatuses, which allow egress of the aorta, esophagus, and vagal nerves into the abdomen and ingress of the vena cava and thoracic duct into the chest.

The chest wall is composed of layers of muscle, bony ribs, costal cartilages, sternum, clavicles, and scapulae. In addition, important neurovascular bundles course along each rib, containing an intercostal nerve, artery, and vein. The inner lining of the chest wall is the parietal pleura. The visceral pleura invests the lungs. Between the visceral and parietal pleurae is a potential space, which, under normal conditions, contains a small amount of fluid that serves mainly as a lubricant.

The lungs occupy most of the volume of each hemithorax. Each is divided into lobes. The right lung has three lobes, and the left lung has two lobes. Each lobe is further divided into segments.

The trachea enters through the thoracic inlet and descends to the carina at thoracic vertebral level 4, where it divides into the right and left mainstem bronchi. Each mainstem bronchus divides into lobar bronchi. The bronchi continue to arborize to supply the pulmonary segments and subsegments.

The heart is a mediastinal structure contained within the pericardium. The right atrium receives blood from the superior vena cava (SVC) and the inferior vena cava (IVC). Right atrial blood passes through the tricuspid valve into the right ventricle. Right ventricular contraction forces blood through the pulmonary valve and into the pulmonary arteries. Blood circulates through the lungs, where it acquires oxygen and releases carbon dioxide.

Oxygenated blood courses through the pulmonary veins to the left atrium. The left heart receives small amounts of nonoxygenated blood via the thebesian veins, which drain the heart, and the bronchial veins. Left atrial blood proceeds through the mitral valve into the left ventricle.

Left ventricular contraction propels blood through the aortic valve into the coronary circulation and the thoracic aorta, which exits the chest through the diaphragmatic hiatus into the abdomen. A ligamentous attachment (a remnant of the ductus arteriosus) exists between the descending thoracic aorta and the pulmonary artery just beyond the takeoff of the left subclavian artery.

The esophagus exits the neck to enter the posterior mediastinum. Through much of its course, it lies posterior to the trachea. In the upper thorax, it lies slightly to the right, with the aortic arch and descending thoracic aorta to its left. Inferiorly, the esophagus turns leftward and enters the abdomen through the esophageal diaphragmatic hiatus.

The thoracic duct arises primarily from the cisterna chyli in the abdomen. It traverses the diaphragm and runs cephalad through the posterior mediastinum in proximity to the spinal column. It enters the neck and veers to the left to empty into the left subclavian vein.

Pathophysiology

The major pathophysiologies encountered in blunt chest trauma involve derangements in the flow of air, blood, or both in combination. Sepsis due to leakage of alimentary tract contents, as in esophageal perforations, also must be considered.

Blunt trauma commonly results in chest-wall injuries (eg, rib fractures). The pain associated with these injuries can make breathing difficult, and this may compromise ventilation. Direct lung injuries, such as pulmonary contusions (see the image below), are frequently associated with major chest trauma and may impair ventilation by a similar mechanism. Shunting and dead-space ventilation produced by these injuries can also impair oxygenation.

Left pulmonary contusion following a motor vehicle Left pulmonary contusion following a motor vehicle accident involving a pedestrian.

Space-occupying lesions (eg, pneumothorax, hemothorax, and hemopneumothorax) interfere with oxygenation and ventilation by compressing otherwise healthy lung parenchyma. A special concern is tension pneumothorax, in which pressure continues to build in the affected hemithorax as air leaks from the pulmonary parenchyma into the pleural space. This can push mediastinal contents toward the opposite hemithorax. Distortion of the SVC by this mediastinal shift can result in decreased blood return to the heart, circulatory compromise, and shock.

At the molecular level, animal experimentation supports a mediator-driven inflammatory process that further leads to respiratory insult after chest trauma. After blunt chest trauma, several blood-borne mediators are released, including interleukin (IL)-6, tumor necrosis factor (TNF), and prostanoids. These mediators are thought to induce secondary cardiopulmonary changes.

Blunt trauma that causes significant cardiac injuries (eg, chamber rupture) or severe great-vessel injuries (eg, thoracic aortic disruption) frequently results in death before adequate treatment can be instituted. This is due to immediate and devastating exsanguination or loss of cardiac pump function, which causes hypovolemic or cardiogenic shock and death.

Sternal fractures are rarely of any consequence, except when they result in blunt cardiac injuries.

Etiology

By far the most important cause of significant blunt chest trauma is motor vehicle accidents (MVAs). MVAs account for 70-80% of such injuries. As a result, preventive strategies to reduce MVAs have been instituted in the form of speed limit restriction and the use of restraints. Vehicles striking pedestrians, falls, and acts of violence are other causative mechanisms. Blast injuries can also result in significant blunt thoracic trauma.

Epidemiology

Trauma is responsible for more than 100,000 deaths annually in the United States.[1]  Estimates of thoracic trauma frequency indicate that injuries occur in 12 persons per 1 million population per day. Approximately 33% of these injuries necessitate hospital admission. Overall, blunt thoracic injuries are directly responsible for 20-25% of all deaths, and chest trauma is a major contributor in another 50% of deaths.

Prognosis

For the great majority of patients with blunt chest trauma, outcome and prognosis are excellent. Most (>80%) require either no invasive therapy or, at most, a tube thoracostomy to effect resolution of their injuries. The most important determinant of outcome is the presence or absence of significant associated injuries of the central nervous system, abdomen, and pelvis.

Some injuries, such as cardiac chamber rupture, thoracic aortic rupture, injuries of the intrathoracic IVC and SVC, and delayed recognition of esophageal rupture, are associated with high morbidity and mortality.

A study using data from the TraumaRegister of the German Trauma Society (N = 50,519) found obesity to have a negative impact on outcomes after blunt chest trauma (ie, increased duration of mechanical ventilation, intensive care unit [ICU] stay, and hospital stay), though it did not document a comparable effect on mortality.[3]

A study by Beshay et al (N = 630) found that the presence of severe lung contusion, a higher Injury Severity Score (ISS), a higher Abbreviated Injury Scale (AIS) score in the thoracic region, and advanced age were independent risk factors directly related to higher mortality.[4]

Refaely et al analyzed clinical outcomes in patients with blunt and penetrating chest injuries who underwent urgent thoracotomy (ie, thoracotomy performed in the operating room within the first 48 hours of the patient's intensive care unit [ICU] stay) and found that mortality was higher in the blunt chest trauma group.[5] ​ They suggested that in both penetrating and blunt chest trauma, urgent thoracotomy should be performed as quickly as possible and should be limited to damage control and that acidosis and hypothermia should be treated extremely aggressively before, during, and after the procedure.

 

Presentation

History and Physical Examination

The clinical presentation of patients with blunt chest trauma varies widely and ranges from minor reports of pain to florid shock.[6] The presentation depends on the mechanism of injury and the organ systems injured.

Obtaining as detailed a clinical history as possible is extremely important in the assessment of a patient who has sustained blunt thoracic trauma. The time of injury, mechanism of injury, estimates of motor vehicle accident (MVA) velocity and deceleration, and evidence of associated injury to other systems (eg, loss of consciousness) are all salient features of an adequate clinical history. Information should be obtained directly from the patient whenever possible and from other witnesses to the accident if available.

For the purposes of this discussion, blunt thoracic injuries may be divided into the following three broad categories:

  • Chest-wall fractures, dislocations, and barotrauma (including diaphragmatic injuries)
  • Blunt injuries of the pleurae, lungs, and aerodigestive tracts
  • Blunt injuries of the heart, great arteries, veins, and lymphatic vessels

This article presents a concise exegesis of the clinical features of each condition in these categories, which then serves as the basis for outlining indications for medical and surgical therapy for these conditions (see Treatment).

The American Association for the Study of Trauma (AAST) has developed several scales for assessing the severity of injury to organs that may be affected by blunt chest trauma.[7, 8]

 

Workup

Approach Considerations

Initial emergency workup of a patient with multiple injuries should begin with the ABCs (airway, breathing, and circulation), with appropriate intervention taken for each step. Subsequent steps in the workup (see below) may include laboratory studies, radiography, computed tomography (CT), ultrasonography (US), endoscopy, and electrocardiography (ECG).

In the setting of blunt chest trauma with suspected cardiac injury, the American College of Radiology (ACR) has made the following assessments regarding appropriate use of imaging in hemodynamically stable patients[9] :

  • Transthoracic echocardiography (TTE), resting - Usually appropriate 
  • Radiography of the chest - Usually appropriate 
  • CT of the chest with intravenous (IV) contrast - Usually appropriate 
  • CT of the chest without and with IV contrast - Usually appropriate 
  • CT angiography (CTA) of the chest with IV contrast - Usually appropriate 
  • CTA of chest without and with IV contrast - Usually appropriate 
  • Transesophageal echocardiography (TEE) - May be appropriate 
  • CT of the chest without IV contrast - May be appropriate 
  • CT of heart function and morphology with IV contrast - May be appropriate

For hemodynamically unstable patients, the assessments are as follows[9] :

  • TTE, resting - Usually appropriate 
  • Radiography of the chest - Usually appropriate 
  • CT of the chest with IV contrast - Usually appropriate 
  • CT of the chest without and with IV contrast - Usually appropriate 
  • CTA of the chest with IV contrast - Usually appropriate 
  • CTA of chest without and with IV contrast - Usually appropriate 
  • CT of heart function and morphology with IV contrast - Usually appropriate
  • TEE - May be appropriate
  • CT of the chest without IV contrast - May be appropriate
  • CTA of coronary arteries with IV contrast - May be appropriate

Laboratory Studies

A complete blood count (CBC) is a routine laboratory test for most trauma patients. The CBC helps gauge blood loss, though it is not entirely reliable for accurately determining acute blood loss. Other important information provided includes platelet and white blood cell (WBC) counts, with or without differential.

Arterial blood gas (ABG) analysis, though not as important in the initial assessment of trauma victims, is important in their subsequent management. ABG determinations are an objective measure of ventilation, oxygenation, and acid-base status, and their results help guide therapeutic decisions such as the need for endotracheal intubation and subsequent extubation.

Patients who are seriously injured and require fluid resuscitation should have periodic monitoring of their electrolyte status. This can help avoid problems such as hyponatremia or hypernatremia. The etiology of certain acid-base abnormalities can also be identified (eg, chloride-responsive metabolic alkalosis or hyperchloremic metabolic acidosis).

The coagulation profile, including prothrombin time (PT)/activated partial thromboplastin time (aPTT), fibrinogen, fibrin degradation product, and D-dimer analyses, can be helpful in the management of patients who receive massive transfusions (eg, >10 units of packed red blood cells [RBCs]). Patients who manifest hemorrhage that cannot be explained by surgical causes should also have their profile monitored.

Whereas elevated serum troponin I levels correlate with the presence of echocardiographic or ECG abnormalities in patients with significant blunt cardiac injuries, these levels have low sensitivity and predictive values in diagnosing myocardial contusion in those without such injuries. Accordingly, troponin I level determination does not, by itself, help predict the occurrence of complications that may necessitate admission to the hospital. Accordingly, its routine use in this clinical situation is not well supported.[10, 11]

Measurement of serum myocardial muscle creatine kinase isoenzyme (creatine kinase-MB) levels is frequently performed in patients with possible blunt myocardial injuries. The test is rapid and inexpensive. This diagnostic modality has been criticized because of poor sensitivity, specificity, and positive predictive value in relation to clinically significant blunt myocardial injuries.

Lactate is an end product of anaerobic glycolysis and, as such, can be used as a measure of tissue perfusion. Well-perfused tissues mainly use aerobic glycolytic pathways. Persistently elevated lactate levels have been associated with poorer outcomes. Patients whose initial lactate levels are high but are rapidly cleared to normal have been resuscitated well and have better outcomes.

Type and crossmatch are among the most important blood tests in the evaluation and management of a seriously injured trauma patient, especially one who is predicted to require major operative intervention.

Plain and Contrast Radiography

Chest radiography

The chest x-ray (CXR) is the initial radiographic study of choice in patients with thoracic blunt trauma. A chest radiograph is an important adjunct in the diagnosis of many conditions, including chest-wall fractures, pneumothorax, hemothorax, and injuries to the heart and great vessels (eg, enlarged cardiac silhouette, widened mediastinum).

In contrast, certain cases arise in which physicians should not wait for a chest radiograph to confirm clinical suspicion. The classic example is a patient presenting with decreased breath sounds, a hyperresonant hemithorax, and signs of hemodynamic compromise (ie, tension pneumothorax). This scenario warrants immediate decompression before a chest radiograph is obtained.[12]

A 2012 study by Paydar et al indicated that routine chest radiography in stable blunt trauma patients may be of low clinical value. The authors proposed that careful physical examination and history taking can accurately identify those patients at low risk for chest injury, thus making routine radiographs unnecessary.[13]

Aortography

Aortography has been the criterion standard for diagnosing traumatic thoracic aortic injuries. However, its limited availability and the logistics of moving a relatively critical patient to a remote location make it less desirable. In addition, the introduction of spiral CT scanners, which have 100% sensitivity and greater than 99% specificity, has caused the role of aortography in the evaluation of trauma patients to decline.

However, where spiral CT is equivocal, aortography can provide a more exact delineation of the location and extent of aortic injuries. Aortography is much better at demonstrating injuries of the ascending aorta. In addition, it is superior for imaging injuries of the thoracic great vessels.[14, 15]

Contrast esophagography

Contrast esophagograms are indicated for patients with possible esophageal injuries in whom esophagoscopy results (see Endoscopy) are negative. Esophagography is first performed with water-soluble contrast media. If this provides a negative result, a barium esophagogram is obtained. If these results are also negative, esophageal injury is reliably excluded.

Esophagoscopy and esophagography are each approximately 80-90% sensitive for esophageal injuries. These studies are complementary and, when performed in sequence, identify nearly 100% of esophageal injuries.

Computed Tomography

Because of the relative insensitivity of chest radiography for identifying significant injuries, CT of the chest is frequently performed in the trauma bay in the hemodynamically stable patient. In one study, 50% of patients with normal chest radiographs were found to have multiple injuries on chest CT. As a result, obtaining a chest CT scan in a supposedly stable patient with significant mechanism of injury is becoming routine practice.

Spiral (helical) CT and CT angiography (CTA) are being used more commonly in the diagnosis of patients with possible blunt aortic injuries. Most authors recommend that positive findings or findings suggestive of an aortic injury (eg, mediastinal hematoma) be augmented by aortography for more precise definition of the location and extent of the injury.[16, 17, 18]

In a study by Akoglu et al, abdominal CT alone or combined with cervical spinal CT detected almost all occult small pneumothoraces in one study of patients with blunt trauma, whereas cervical spinal CT alone detected only one third of cases.[19]

Ultrasonography

Thoracic ultrasonography

Ultrasound examinations of the pericardium, heart, and thoracic cavities can be expeditiously performed by surgeons and emergency department (ED) physicians within the ED. Pericardial effusions or tamponade can be reliably recognized, as can hemothoraces associated with trauma.[20] The sensitivity, specificity, and overall accuracy of US in these settings are all greater than 90%. Point-of-care US (PoCUS) in the ED has been used as a means of detecting rib fractures in patients who have sustained blunt chest trauma,[21]  as well as for detecting pneumothorax.[22, 23]

Focused assessment with sonography for trauma

The focused assessment with sonography for trauma (FAST) is routinely conducted in many trauma centers. Although this examination mainly deals with abdominal trauma, the first step is to obtain an image of the heart and pericardium to assess for evidence of intrapericardial bleeding.

Echocardiography

Transesophageal echocardiography (TEE) has been extensively studied for use in the workup of possible blunt rupture of the thoracic aorta. Its sensitivity, specificity, and accuracy in the diagnosis of this injury are each approximately 93-96%.

The advantages of TEE include the easy portability, the absence of a need for contrast material, the minimal invasiveness, and the short time required to perform it. TEE can also be used intraoperatively to help identify cardiac abnormalities and monitor cardiac function.[24, 25, 26]  The disadvantages include the requirement for operator expertise, the long learning curve, and the relative weakness of the modality for helping identify injuries to the descending aorta.

Transthoracic echocardiography (TTE) can help identify pericardial effusions and tamponade, valvular abnormalities, and disturbances in cardiac wall motion. TTE is also performed in cases where patients have possible blunt myocardial injuries and abnormal ECG findings.

Endoscopy

Esophagoscopy

Esophagoscopy is the initial diagnostic procedure of choice in patients with possible esophageal injuries. Either flexible or rigid esophagoscopy is appropriate, and the choice depends on the experience of the clinician. Some authors prefer rigid esophagoscopy to evaluate the cervical esophagus and flexible esophagoscopy for possible injuries of the thoracic and abdominal esophagus. If esophagoscopy findings are negative, esophagography should be performed as outlined above.

Bronchoscopy

Fiberoptic or rigid bronchoscopy is performed in patients with possible tracheobronchial injuries. Both techniques are extremely sensitive for the diagnosis of these injuries. Fiberoptic bronchoscopy offers the advantage of allowing an endotracheal tube to be loaded onto the scope and the endotracheal intubation to be performed under direct visualization if necessary.

Electrocardiography

The 12-lead ECG is a standard test performed on all thoracic trauma victims. ECG findings can help identify new cardiac abnormalities and help discover underlying problems that may impact treatment decisions. Furthermore, it is the most important discriminator to help identify patients with clinically significant blunt cardiac injuries.

Patients with possible blunt cardiac injuries and normal ECG findings require no further treatment or investigation for this injury. The most common ECG abnormalities found in patients with blunt cardiac injuries are tachyarrhythmias and conduction disturbances, such as first-degree heart block and bundle-branch blocks.

However, according to a 2012 practice management guideline from the Eastern Association for the Surgery of Trauma (see Guidelines), ECG alone should not be considered sufficient for ruling out blunt cardiac injury. The guideline recommends obtaining an admission ECG and troponin I from all patients in whom blunt cardiac injury is suspected and states that such injury can be ruled out only if both the ECG and the troponin I level are normal.[27]

 

Treatment

Approach Considerations

Indications for operative intervention

Operative intervention is rarely necessary in blunt thoracic injuries. In one report, only 8% of cases with blunt thoracic injuries required an operation. Most such injuries can be treated with supportive measures and simple interventional procedures such as tube thoracostomy.

Indications for surgical intervention in blunt traumatic injuries may be categorized according to the classification system previously described (see Presentation). These indications may be further stratified into conditions necessitating an immediate operation and those in which surgery is needed for delayed manifestations or complications of trauma.

Chest-wall fractures, dislocations, and barotrauma (including diaphragmatic injuries)

Indications for immediate surgery include the following:

  • Traumatic disruption with loss of chest-wall integrity
  • Blunt diaphragmatic injuries

Relatively immediate and long-term indications for surgery include the following:

  • Delayed recognition of blunt diaphragmatic injury
  • Development of a traumatic diaphragmatic hernia

Blunt injuries of pleurae, lungs, and aerodigestive tract

Indications for immediate surgery include the following:

  • Massive air leak following chest-tube insertion
  • Massive hemothorax or continued high rate of blood loss via the chest tube (ie, 1500 mL of blood upon chest-tube insertion or continued loss of 250 mL/hr for 3 consecutive hours)
  • Radiographically or endoscopically confirmed tracheal, major bronchial, or esophageal injury
  • Recovery of gastrointestinal (GI) tract contents via the chest tube

Relatively immediate and long-term indications for surgery include the following:

  • Chronic clotted hemothorax or fibrothorax, especially when associated with a trapped or nonexpanding lung
  • Empyema
  • Traumatic lung abscess
  • Delayed recognition of tracheobronchial or esophageal injury
  • Tracheoesophageal fistula
  • Persistent thoracic duct fistula/chylothorax

Blunt injuries to heart, great arteries, veins, and lymphatic vessels

Indications for immediate surgery include the following:

  • Cardiac tamponade
  • Radiographic confirmation of a great-vessel injury
  • Embolism into the pulmonary artery or the heart

Relatively immediate and long-term indications for surgery include the late recognition of a great-vessel injury (eg, development of traumatic pseudoaneurysm).

Contraindications for operative intervention

No distinct, absolute contraindications exist for surgery in blunt thoracic trauma. Rather, guidelines have been instituted to define which patients have clear indications for surgery (eg, massive hemothorax, continued high rates of blood loss via chest tube).

A controversial area has been the use of emergency department (ED) thoracotomy in patients with blunt trauma who present without vital signs. The results of this approach in this particular patient population have been dismal and have led many authors to condemn it. (See Guidelines.[28] )

Chest-Wall Fractures, Dislocations, and Barotrauma

Rib fractures

Rib fractures are the most common blunt thoracic injuries. Ribs 4-10 are the ones most frequently involved. Patients usually report inspiratory chest pain and discomfort over the fractured rib or ribs. Physical findings include local tenderness and crepitus over the site of the fracture. If a pneumothorax is present, breath sounds may be decreased and resonance to percussion may be increased.

Rib fractures may also be a marker for other associated significant injury, both intrathoracic and extrathoracic. In one report, 50% of patients with blunt cardiac injury have rib fractures. Fractures of ribs 8-12 should raise the suggestion of associated abdominal injuries. Lee et al reported a 1.4- and 1.7-fold increase in the incidence of splenic and hepatic injury, respectively, in those with rib fractures.

Elderly patients with three or more rib fractures have been shown to have a fivefold increase in mortality and a fourfold increase in the incidence of pneumonia.

Effective pain control is the cornerstone of medical therapy for patients with rib fractures. For most patients, this consists of oral or parenteral analgesic agents. Intercostal nerve blocks may be feasible for those with severe pain who do not have numerous rib fractures. A local anesthetic with a relatively long duration of action (eg, bupivacaine) can be used. Patients with multiple rib fractures whose pain is difficult to control can be treated with epidural analgesia.

Adjunctive measures in the care of these patients include early mobilization and aggressive pulmonary toilet. Rib fractures typically do not require surgery. Pain relief and the establishment of adequate ventilation are the therapeutic goals.

There has been increasing interest in open reduction and internal fixation (ORIF) in selected patients with rib fractures,[29] though the patient subset that would benefit most has not been fully defined. The Eastern Association for the Surgery of Trauma (EAST) conditionally recommended ORIF of rib fractures in adult patients with flail chest to reduce mortality, duration of mechanical ventilation, length of stay in the hospital or intensive care unit (ICU), incidence of pneumonia, and need for tracheostomy.[30] ; no recommendation was made for pain control or for any of the outcomes in patients without flail chest. It remains to be determined what role operative fixation may play in this setting.[31]

Rarely, a fractured rib lacerates an intercostal artery or other vessel, resulting in the need for surgical control to achieve hemostasis acutely. In the chronic phase, nonunion and persistent pain may also necessitate an operation.

Flail chest

A flail chest, by definition, involves three or more consecutive rib fractures in two or more places, which produce a free-floating, unstable segment of chest wall. Separation of the bony ribs from their cartilaginous attachments, termed costochondral separation, can also cause flail chest.

Patients report pain at the fracture sites, pain upon inspiration, and, frequently, dyspnea. Physical examination reveals paradoxical motion of the flail segment. The chest wall moves inward with inspiration and outward with expiration. Tenderness at the fracture sites is the rule. Dyspnea, tachypnea, and tachycardia may be present. The patient may overtly exhibit labored respiration due to the increased work of breathing induced by the paradoxical motion of the flail segment.

A significant amount of force is required to produce a flail segment. Therefore, associated injuries are common and should be aggressively sought. The clinician should specifically be aware of the high incidence of associated thoracic injuries such as pulmonary contusions and closed head injuries, which, in combination, significantly increase the mortality associated with flail chest.

All of the treatments mentioned above for rib fractures are suitable for flail chest. Respiratory distress or insufficiency can ensue in some patients with flail chest because of severe pain secondary to the multiple rib fractures, the increased work of breathing, and the associated pulmonary contusion. This may necessitate endotracheal intubation and positive-pressure mechanical ventilation. Intravenous fluids are administered judiciously; fluid overloading can precipitate respiratory failure, especially in those with significant pulmonary contusions.

To stabilize the chest wall and avoid endotracheal intubation and mechanical ventilation, various operations have been devised for correcting flail chest (eg, pericostal sutures, application of external fixation devices, and placement of plates or pins for internal fixation). With improved understanding of pulmonary mechanics and better mechanical ventilatory support, surgical therapy has not proved superior to supportive and medical measures.[31] Most authors, however, would agree that stabilization is warranted if thoracotomy is indicated for another reason.

The EAST has published a practice management guideline on the management of flail chest and pulmonary contusion.[32]  (See Guidelines.)

First- and second-rib fractures

First- and second-rib fractures are considered a separate entity from other rib fractures because of the excessive energy transfer required to injure these sturdy and well-protected structures. First- and second-rib fractures are harbingers of associated cranial, major vascular, thoracic, and abdominal injuries. The clinician should aggressively seek to exclude the presence of these other injuries.

Pain control and pulmonary toilet are the specific treatment measures for rib fractures. First- and second-rib fractures do not require surgical therapy. An exception to this would be the need to excise a greatly displaced bone fragment.

Clavicular fractures

Clavicular fractures are among the most common injuries to the shoulder-girdle area. Common mechanisms include a direct blow to the shaft of the bone, a fall on an outstretched hand, and a direct lateral fall against the shoulder. Approximately 75-80% of clavicular fractures occur in the middle third of the bone. Patients report tenderness over the fracture site and pain with movement of the ipsilateral shoulder or arm.

Physical findings include anteroinferior positioning of the ipsilateral arm as compared with the contralateral arm. The proximal segment of the clavicle is displaced superiorly because of the action of the sternocleidomastoid.

Nearly all clavicular fractures can be managed without surgery. Primary treatment consists of immobilization with a figure-eight dressing, a clavicle strap, or a similar dressing or sling. Oral analgesics can be used to control pain. Surgery is rarely indicated. Surgical intervention is occasionally indicated for the reduction of a badly displaced fracture.

Sternoclavicular joint dislocations

Strong lateral compressive forces against the shoulder can cause sternoclavicular joint dislocation. Anterior dislocation is more common than posterior dislocation. Patients report pain with arm motion or when a compressive force is applied against the affected shoulder. The ipsilateral arm and shoulder may be anteroinferiorly displaced. With anterior dislocations, the medial end of the clavicle can become more prominent. With posterior dislocations, a depression may be discernible adjacent to the sternum. Associated injuries to the trachea, subclavian vessels, or brachial plexus can occur with posterior dislocations.

Closed or open reduction is generally advised. Treatment strategies depend on whether the patient has an anterior or posterior dislocation.

For anterior dislocations, local anesthesia and sedative medications are administered, and lateral traction is applied to the affected arm that is placed in abduction and extension. This maneuver, combined with direct pressure over the medial clavicle, can occasionally reduce an anterior dislocation. For posterior dislocations, a penetrating towel clip can be used to grasp the medial clavicle to provide the necessary purchase for anterior manual traction to reduce the joint. Proper levels of pain control, up to and including general anesthesia, are provided. If closed reduction fails, open reduction is performed.

Sternal fractures

Most sternal fractures are caused by motor vehicle accidents (MVAs). The upper and middle thirds of the bone are most commonly affected in a transverse fashion. Patients report pain around the injured area. Inspiratory pain or a sense of dyspnea may be present. Physical examination reveals local tenderness and swelling. Ecchymosis is noted in the area around the fracture. A palpable defect or fracture-related crepitus may be present.

Associated injuries occur in 55-70% of patients with sternal fractures. The most common associated injuries are rib fractures, long-bone fractures, and closed head injuries. The association of blunt cardiac injuries with sternal fractures has been a source of great debate. Blunt cardiac injuries are diagnosed in fewer than 20% of patients with sternal fractures. Caution should be exercised before myocardial injury is completely excluded. The workup should begin with electrocardiography (ECG).

Most sternal fractures require no therapy specifically directed at correcting the injury. Patients are treated with analgesics and are advised to minimize activities that involve the use of pectoral and shoulder-girdle muscles. The most important aspect of the care for these patients is to exclude blunt myocardial and other associated injuries.

Patients who are experiencing severe pain related to the fracture and those with a badly displaced fracture are candidates for ORIF. Various techniques have been described, including wire suturing and the placement of plates and screws. The latter technique is associated with better outcomes.

Scapular fractures

Scapular fractures are uncommon. Their main clinical importance is the high-energy forces required to produce them and the attendant high incidence of associated injuries. The rate of associated injuries is 75-100%, most commonly involving the head, chest, or abdomen.

Patients with scapular fractures report pain around the scapula. Tenderness, swelling, ecchymosis, and fracture-related crepitus can all be present. The fracture is most frequently located in the body or neck of the scapula. More than 30% of scapular fractures are missed during the initial patient evaluation. The discovery of a scapular fracture should prompt a concerted effort to exclude major vascular injuries and injuries of the thorax, abdomen, and neurovascular bundle of the ipsilateral arm.

Shoulder immobilization is the standard initial treatment. This can be accomplished by placing the arm in a sling or shoulder harness. Range-of-motion (ROM) exercises are started as soon as possible to help prevent loss of shoulder mobility. Surgery is infrequently indicated. Involvement of the glenoid, acromion, or coracoid may require ORIF with the goal of maintaining proper shoulder mobility.

Scapulothoracic dissociation

Sometimes called flail shoulder, this rare injury occurs when very strong traction forces pull the scapula and other elements of the shoulder girdle away from the thorax. The muscular, vascular, and nervous components of the shoulder and arm are severely compromised. Physical findings include significant hematoma formation and edema in the shoulder area. Neurologic deficits include loss of sensation and motor function distal to the shoulder. Pulses in the arm are typically decreased or lost as a consequence of axillary artery thrombosis.

No specific medical therapy has been developed for this devastating injury. Surgery is rarely indicated early in the course of the injury. If the affected limb retains sufficient neurovascular integrity and function, operative fixation may be indicated to restore shoulder stability. Many scapulothoracic dissociations result in a flail limb that is insensate or is associated with severe pain due to proximal brachial plexus injury. An above-elbow amputation may be the best approach for these patients.

Chest-wall defects

The management of large open chest-wall defects initially requires irrigation and debridement of devitalized tissue to prevent progression into a necrotizing wound infection. Once the infection is under control, subsequent treatment depends on the severity and level of defect. Reconstructive options range from skin grafting to well-vascularized flaps to a variety of meshes with or without methylmethacrylate. The choice of reconstruction depends upon the depth of the defect.

Traumatic asphyxia

The curious clinical constellation known as traumatic asphyxia is the result of thoracic injury due to a strong crushing mechanism, such as might occur when an individual is pinned under a very heavy object. Some effects of the injury are compounded if the glottis is closed during application of the crushing force.

Patients present with cyanosis of the head and neck, subconjunctival hemorrhage, periorbital ecchymosis, and petechiae of the head and neck. The face frequently appears very edematous or moonlike. Epistaxis and hemotympanum may be present. A history of loss of consciousness, seizures, or blindness may be elicited. Neurologic sequelae are usually transient. Recognition of this syndrome should prompt a search for associated thoracic and abdominal injuries.

The head of the patient's bed should be elevated to approximately 30° to decrease transmission of pressure to the head. Adequate airway and ventilatory status must be assured, and the patient is given supplemental oxygen. Serial neurologic examinations are performed while the patient is monitored in an intensive care setting. No specific surgical therapy is indicated for traumatic asphyxia. Associated injuries to the torso and head frequently necessitate surgical intervention.

Blunt diaphragmatic injuries

Diaphragmatic injuries are relatively uncommon. Blunt mechanisms, usually a result of high-speed MVAs, cause approximately 33% of diaphragmatic injuries. Most diaphragmatic injuries recognized clinically involve the left side, though autopsy and computed tomography (CT)-based investigations suggest a roughly equal incidence for both sides.

This injury should be considered in patients who sustain a blow to the abdomen and present with dyspnea or respiratory distress. Because of the very high incidence of associated injuries (eg, major splenic or hepatic trauma), it is not unusual for these patients to present with hypovolemic shock.

Most diaphragmatic injuries are diagnosed incidentally at the time of laparotomy or thoracotomy for associated intra-abdominal or intrathoracic injuries. Initial chest radiographs are normal. Findings suggestive of diaphragmatic disruption on chest radiographs may include abnormal location of the nasogastric tube in the chest, ipsilateral hemidiaphragm elevation, or abdominal visceral herniation into the chest.

In a patient with multiple injuries, CT is not very accurate, and magnetic resonance imaging (MRI) is not very realistic. Bedside emergency ultrasonography is gaining popularity, and case reports in the literature have supported its use in the evaluation of the diaphragm. Diagnostic laparoscopy and thoracoscopy have also been reported to be successful in the identification of diaphragmatic injury.

A confirmed diagnosis or the suggestion of blunt diaphragmatic injury is an indication for surgery. Blunt diaphragmatic injuries typically produce large tears measuring 5-10 cm or longer. Most injuries are best approached via laparotomy. An abdominal approach facilitates exposure of the injury and allows exploration for associated abdominal organ injuries. The exception to this rule is a posterolateral injury of the right hemidiaphragm. This injury is best approached through the chest because the liver obscures the abdominal approach.

Most injuries can be repaired primarily with a continuous or interrupted braided suture (1-0 or larger). Centrally located injuries are most easily repaired. Lateral injuries near the chest wall may require reattachment of the diaphragm to the chest wall by encirclement of the ribs with suture during the repair. Synthetic mesh made of polypropylene or Dacron is occasionally needed to repair large defects.[33, 34]

Blunt Injuries to Pleurae, Lungs, and Aerodigestive Tract

Pneumothorax

Pneumothoraces in blunt thoracic trauma are most frequently caused when a fractured rib penetrates the lung parenchyma. However, this is not an absolute rule. Pneumothoraces can result from deceleration or barotrauma to the lung without associated rib fractures.

Patients report inspiratory pain or dyspnea and pain at the sites of the rib fractures. Physical examination demonstrates decreased breath sounds and hyperresonance to percussion over the affected hemithorax. In practice, many patients with traumatic pneumothoraces also have some element of hemorrhage, producing a hemopneumothorax.

Patients with pneumothoraces require pain control and pulmonary toilet. All patients with pneumothoraces due to trauma need a tube thoracostomy. The chest tube is connected to a collection system (eg, Pleur-evac) that is entrained to suction at a pressure of approximately –20 cm H2O. Suction continues until no air leak is detected. The tube is then disconnected from suction and placed to water seal. If the lung remains fully expanded, the tube may be removed and another chest radiograph obtained to ensure continued complete lung expansion.

A prospective, observational, multicenter study sought to determine which factors predicted failed observation in blunt trauma patients.[35]  Using data from 569 blunt trauma patients, the study identified 588 with an occult pneumothorax (OPTX); one group underwent immediate tube thoracostomy, and the second group was observed.

Patients in whom observation failed spent more days on ventilators and had longer hospital and intensive care unit lengths of stay; 15% developed complications.[35]  No patient in this group developed a tension pneumothorax or experienced adverse events by delaying tube thoracostomy. The investigators concluded that whereas most blunt trauma patients with OPTX can be carefully monitored without tube thoracostomy, OPTX progression and respiratory distress were significant predictors of failed observation.

Open pneumothorax

Open pneumothorax is more commonly caused by penetrating mechanisms but may rarely occur with blunt thoracic trauma.

Patients are typically in respiratory distress due to collapse of the lung on the affected side. Physical examination should reveal a chest-wall defect that is larger than the cross-sectional area of the larynx. The affected hemithorax demonstrates a significant-to-complete loss of breath sounds. The increased intrathoracic pressure can shift the contents of the mediastinum to the opposite side, decreasing the return of blood to the heart, potentially leading to hemodynamic instability.

Treatment for an open pneumothorax consists of placing a three-way occlusive dressing over the wound to preclude continued ingress of air into the hemithorax and to allow egress of air from the chest cavity. A tube thoracostomy is then performed. Pain control and pulmonary toilet measures are applied.

After initial stabilization, most patients with open pneumothoraces and loss of chest-wall integrity undergo operative wound debridement and closure. Those with loss of large chest-wall segments may need reconstruction and closure with prosthetic devices (eg, polytetrafluoroethylene patches). Patch placement can serve as definitive therapy or as a bridge to formal closure with rotational or free tissue flaps.

For low chest-wall injuries, some authors describe detachment of the diaphragm, with operative reattachment at a higher intrathoracic level. This converts the open chest wound into an open abdominal wound, which is easier to manage.

Traumatic pulmonary herniation through the ribs, though uncommon, may occur after chest trauma. Unless incarceration or infarction is evident, immediate repair is not indicated.

Tension pneumothorax

The mechanisms that produce tension pneumothoraces are the same as those that produce simple pneumothoraces. However, with a tension pneumothorax, air continues to leak from an underlying pulmonary parenchymal injury, increasing pressure within the affected hemithorax.

Patients are typically in respiratory distress. Breath sounds are severely diminished to absent, and the hemithorax is hyperresonant to percussion. The trachea is deviated away from the side of the injury. The mediastinal contents are shifted away from the affected side. This results in decreased venous return of blood to the heart. The patient exhibits signs of hemodynamic instability, such as hypotension, which can rapidly progress to complete cardiovascular collapse.

Immediate therapy for this life-threatening condition includes decompression of the affected hemithorax by means of needle thoracostomy. A large-bore (ie, 14- to 16-gauge) needle is inserted through the second intercostal space in the midclavicular line. A tube thoracostomy is then performed. Pain control and pulmonary toilet are instituted.

Hemothorax

Accumulation of blood within the pleural space can be due to bleeding from the chest wall (eg, lacerations of the intercostal or internal mammary vessels attributable to fractures of chest wall elements) or to hemorrhage from the lung parenchyma or major thoracic vessels.

Patients report pain and dyspnea. Physical examination findings vary with the extent of the hemothorax. Most hemothoraces are associated with a decrease in breath sounds and dullness to percussion over the affected area. Massive hemothoraces due to major vascular injuries manifest with the aforementioned physical findings and varying degrees of hemodynamic instability.

Hemothoraces are evacuated by means of tube thoracostomy. Multiple chest tubes may be required. Pain control and aggressive pulmonary toilet are provided. Tube output is monitored closely. Indications for surgery can be based on the initial and cumulative hourly chest tube drainage, in that massive initial output and continued high hourly output are frequently associated with thoracic vascular injuries that require surgical intervention.

Large, clotted hemothoraces may necessitate an operation for evacuation to allow full expansion of the lung and to avoid the development of other complications such as fibrothorax and empyema. Thoracoscopic approaches have been used successfully in the management of this problem.[36]

Pulmonary contusion and other parenchymal injuries

The forces associated with blunt thoracic trauma can be transmitted to the lung parenchyma. This results in pulmonary contusion, characterized by development of pulmonary infiltrates with hemorrhage into the lung tissue.

Clinical findings in pulmonary contusion depend on the extent of the injury. Patients present with varying degrees of respiratory difficulty. Physical examination demonstrates decreased breath sounds over the affected area. Other parenchymal injuries (eg, lacerations) can be produced by fractured ribs and, rarely, by deceleration mechanisms.

Pain control, pulmonary toilet, and supplemental oxygen are the primary therapies for pulmonary contusions and other parenchymal injuries. If the injury involves a large amount of parenchyma, significant pulmonary shunting and dead-space ventilation may develop, necessitating endotracheal intubation and mechanical ventilation.

Laceration or avulsion injuries that cause massive hemothoraces or prolonged high rates of bloody chest-tube output may require thoracotomy for surgical control of bleeding vessels. If central bleeding is identified during thoracotomy, hilar control is gained first. Once the extent of injury is confirmed, it may become necessary to perform a pneumonectomy, with the caveat that trauma pneumonectomy is generally associated with a high mortality (>50%).[37]

The EAST has published a practice management guideline on the management of pulmonary contusion and flail chest.[32]  (See Guidelines.)

Blunt tracheal injuries

Although the incidence of blunt tracheobronchial injuries is low (1-3%), most patients with such injuries die before reaching the hospital. These injuries include fractures, lacerations, and disruptions. Blunt trauma most often produces fractures. These injuries are devastating and are frequently caused by severe rapid deceleration or compressive forces applied directly to the trachea between the sternum and vertebrae.

Patients are in respiratory distress. They typically cannot phonate and frequently present with stridor. Other physical signs include an associated pneumothorax and massive subcutaneous emphysema.

Blunt tracheal injuries are immediately life-threatening and require surgical repair. Bronchoscopy is required to make the definitive diagnosis. The first therapeutic maneuver is the establishment of an adequate airway. If airway compromise is present or probable, a definitive airway is established.

Endotracheal intubation remains the preferred route if feasible. This can be facilitated by arming a flexible bronchoscope with an endotracheal tube and performing the intubation under direct bronchoscopic guidance. The tube must be placed distal to the site of injury. Always be prepared to perform an emergency tracheotomy or cricothyroidotomy to establish an airway if this fails. These maneuvers are best performed in the controlled environment of an operating room.

The operative approach to repair of a blunt tracheal injury includes debridement of the fracture site and restoration of airway continuity with a primary end-to-end anastomosis. Defects of 3 cm or larger frequently require proximal and distal mobilization of the trachea to reduce tension on the anastomosis. The type of incision made for repairing the tracheal injury is determined by the level and extent of injury and the involvement of other thoracic organs.

Blunt bronchial injuries

Rapid deceleration is the most common mechanism causing major blunt bronchial injuries. Many of these patients die of inadequate ventilation or severe associated injuries before definitive therapy can be provided.

Patients are in respiratory distress and present with physical signs consistent with a massive pneumothorax. Ipsilateral breath sounds are severely diminished to absent, and the hemithorax is hyperresonant to percussion. Subcutaneous emphysema may be present and may be massive. Hemodynamic instability may be present and is caused by tension pneumothorax or massive blood loss from associated injuries.

Laceration, tear, or disruption of a major bronchus is life-threatening. These injuries require surgical repair. As with tracheal injuries, establishment of a secure and adequate airway is of primary importance.

Patients with major bronchial lacerations or avulsions have massive air leaks. The approach to repair of these injuries is ipsilateral thoracotomy on the affected side after single-lung ventilation is established on the uninjured side. Some patients cannot tolerate this and require jet-insufflation techniques. Operative repair consists of debridement of the injury and construction of a primary end-to-end anastomosis.

Blunt esophageal injuries

Because of the relatively protected location of the esophagus in the posterior mediastinum, blunt injuries to this organ are rare. Blunt esophageal injuries are usually caused by a sudden increase in esophageal luminal pressure resulting from a forceful blow. Injury occurs predominantly in the cervical region; rarely, intrathoracic and subdiaphragmatic ruptures are also encountered.

Associated injuries to other organs are common. Physical clues to the diagnosis may include subcutaneous emphysema, pneumomediastinum, pneumothorax, or intra-abdominal free air. Patients who present a significant time after the injury may manifest signs and symptoms of systemic sepsis.

General medical supportive measures are appropriate. Fluid resuscitation and broad-spectrum intravenous antibiotics with activity against gram-positive organisms and anaerobic oral flora are administered. Surgery is required.

Injuries identified within 24 hours of their occurrence are treated by debridement and primary closure. Some surgeons choose to reinforce these repairs with autologous tissue. Wide mediastinal drainage is established with multiple chest tubes.

If more than 24 hours has passed since injury, primary repair buttressed by well-vascularized autologous tissue is still the best option if technically feasible. Examples of tissues used to reinforce esophageal repairs include parietal pleura and intercostal muscle. Very distal esophageal injuries can be covered with a tongue of gastric fundus. This is called a Thal patch.

For patients in poor general condition and those with advanced mediastinitis or severe associated injuries, the most prudent choice is esophageal exclusion and diversion. A cervical esophagostomy is made, the distal esophagus is stapled, the stomach is decompressed via gastrostomy, and a feeding jejunostomy tube is placed. Wide mediastinal drainage is established with multiple chest tubes.

Blunt Injuries to Heart, Great Arteries, Veins, and Lymphatic Vessels

Blunt pericardial injuries

Isolated blunt pericardial injuries are rare. Blunt mechanisms produce pericardial tears that can result in herniation of the heart and associated decrements in cardiac output. Physical examination may elicit a pericardial rub.

Most blunt pericardial injuries can be closed by simple pericardiorrhaphy. Large defects that cannot be closed primarily without tension can usually be left open or be patch-repaired.

Blunt cardiac injuries

MVAs are the most common cause of blunt cardiac injuries. Falls, crush injuries, acts of violence, and sporting injuries are other causes. Blunt cardiac injuries range from mild trauma associated only with transient arrhythmias to rupture of the valve mechanisms, interventricular septum, or myocardium (cardiac chamber rupture).

Therefore, patients can be asymptomatic or can manifest signs and symptoms ranging from chest pain to cardiac tamponade (eg, muffled heart tones, jugular venous distention, hypotension) to complete cardiovascular collapse and shock due to rapid exsanguination.

Many patients with blunt cardiac injuries do not require specific therapy. Those who develop an arrhythmia are treated with the appropriate antiarrhythmic drug. Elaboration on these drugs and their administration is beyond the scope of this article.

Patients with severe blunt cardiac injuries who survive to reach the hospital require surgery. Most patients in this group have cardiac chamber rupture due to a high-speed MVA. Right-side involvement is most common, involving the right atrium and right ventricle. These patients present with signs and symptoms of cardiac tamponade or exsanguinating hemorrhage. A few may be stable initially, and diagnosis may be delayed as a result.

Those with tamponade benefit from rapid pericardiocentesis or surgical creation of a subxiphoid window. The next step is to repair the cardiac chamber via cardiorrhaphy. Cardiopulmonary bypass techniques can facilitate this procedure. Unstable patients may benefit from insertion of an intra-aortic counterpulsation balloon pump.

Commotio cordis or sudden cardiac death in an otherwise healthy individual generally results from participation in a sporting event or some form of recreational activity. It is a direct result of blow to the heart just before the T-wave, resulting in ventricular fibrillation. Survival is not unheard of, provided that resuscitation and defibrillation are started within minutes. Preventive strategies include wearing chest-protective gear during sporting activities.[38, 39, 40]

Blunt injuries to thoracic aorta and major thoracic arteries

High-speed MVAs are the most common cause of blunt injuries to the thoracic aorta and the major thoracic arteries. Falls from heights and MVAs involving a pedestrian are other recognized causes. Injury mechanisms include rapid deceleration, production of shearing forces, and direct luminal compression against points of fixation (especially at the ligamentum arteriosum). Many of these patients die of vessel rupture and rapid exsanguination at the scene or before reaching definitive care. Blunt aortic injuries follow closely behind head injury as a cause of death after blunt trauma.

Important historical details include the exact mechanism of injury and estimates of the amount of energy transferred to the patient (eg, magnitude of deceleration). Other important details include whether the victim was ejected from a vehicle or thrown if struck by a vehicle, the height of the fall, and whether other fatalities occurred at the scene.

Physical clues include signs of significant chest-wall trauma (eg, scapular fractures, first- or second-rib fractures, sternal fractures, steering wheel imprint), hypotension, upper-extremity blood pressure differential, loss of upper- or lower-extremity pulses, and thoracic spine fractures. Signs of cardiac tamponade may be present. Decreased breath sounds and dullness to percussion due to massive hemothorax can also be found.

As many as 50% of patients with these devastating, life-threatening injuries have no overt external signs of injury. Therefore, a high index of suspicion is warranted for earlier intervention.

The management of these injuries, especially those of the thoracic aorta, is evolving. Many patients undergo delayed repair of contained descending thoracic aortic ruptures. This approach is most frequently used when severe associated injuries are present that require urgent correction.

Temporizing medical therapy includes the administration of short-acting beta-blockers (eg, labetalol, esmolol) to control the heart rate and to decrease the mean arterial pressure to approximately 60 mm Hg.

Because repair of thoracic aortic injuries using cardiopulmonary bypass is associated with fewer major neurologic complications, some authors advocate stabilization of the victim plus beta-blocker administration until it is feasible to transfer the patient to a facility where the injury can be repaired by means of cardiopulmonary bypass or centrifugal pump techniques. These techniques maintain distal aortic perfusion. Results have been excellent, and postoperative paraplegia rates have been significantly reduced.[41]

Endovascular stent grafts have been developed to repair thoracic aortic injuries.[42] Although several authors have reported success in treating such injuries with endovascular stents, the long-term durability of the stents remains to be established. Further experience with this technique will allow more victims with concomitant severe injuries to become operative candidates.

Techniques for repair of the innominate artery and subclavian vessels vary, depending on the type of injury. For many of these injuries, only lateral arteriorrhaphy is required. Large injuries of the innominate artery are managed first by placing a bypass graft from the ascending aorta to the distal innominate artery. The injury is then approached directly and is oversewn or patched.[43, 44, 45]

Proximal pulmonary arterial injuries are relatively easy to repair when in an anterior location. Posterior injuries frequently necessitate cardiopulmonary bypass. Pulmonary hilar injuries present the possibility of rapid exsanguination and are best treated with pneumonectomy. Peripheral pulmonary arterial injuries are approached easily by thoracotomy on the affected side. They may be repaired or the corresponding pulmonary lobe or segment may be resected.

The EAST has published a practice management guideline on the management of blunt traumatic aortic injury.[46] (See Guidelines.)

Blunt injuries to superior vena cava and major thoracic veins

Injuries limited to the major veins of the thorax are rare. These patients usually present with associated injuries to other major thoracic vascular structures. The clinical history, including mechanisms of injury, and the findings from physical examination are similar to those described for blunt injuries of the thoracic aorta and major thoracic arteries.

Major thoracic venous injuries are amenable to lateral venorrhaphy. If repair proves to be difficult or impossible, injured subclavian or azygos veins can be ligated. Injuries to the thoracic inferior vena cava (IVC) or superior vena cava (SVC) may require shunt placement or cardiopulmonary bypass to facilitate repair.

Blunt injuries to thoracic duct

Thoracic ductal injuries due to blunt mechanisms are rare. They are sometimes found in association with thoracic vertebral trauma. No signs or symptoms are specific for this injury at presentation. The diagnosis is usually delayed and is confirmed when a chest tube is inserted for a pleural effusion and returns chyle. This is termed a chylothorax.

Conservative management with chest-tube drainage is successful in most cases, effecting closure of the ductal injury without surgery. Chyle production can be decreased by maintaining the patient on total parenteral nutrition or by providing enteral nutrition with medium-chain triglycerides as the fat source.

If a fistula persists after an attempt at nonoperative management, thoracotomy is performed to identify and ligate the fistula. This is usually advisable after 2-3 weeks of persistent drainage or if the total lymphocyte count dwindles. Provision of a meal high in fat content (or ice cream) the night before the operation increases the volume of chyle and facilitates identification of the fistula.

General Surgical Approach

Patients with immediately life-threatening injuries that necessitate surgery cannot afford a protracted workup. At minimum, the ABCs (airay, breathing, and circulation) must be established. Frequently, resuscitation efforts in these patients must continue in transit to and in the operating room.

Those with indications for surgery but who are not in extremis should also have their ABCs established. On the basis of the mechanism of injury, clinical history, and physical findings, a search is conducted to exclude associated injuries. Diagnostic procedures (eg, cervical spine radiography; CT of the head, chest, and abdomen; and focused assessment with sonography for trauma [FAST]) are completed if time and the patient's condition permit . Blood is drawn and sent for typing, crossmatching, and other tests (eg, complete blood count and arterial blood gas analysis).

An adequate, secured airway is necessary, as is intravenous access. Monitoring devices (eg, a Foley urinary catheter, central venous pressure monitor, or pulmonary artery catheter) should be considered on the basis of the severity of injury, the patient's preoperative functional status, and the anticipated length of the operation. Some injuries may necessitate the use of single-lung ventilation techniques. This should be discussed with the anesthesiologist as early as possible.

Cardiopulmonary bypass or a centrifugal pump is used when necessary. Patient positioning and choice of incision are very important. A median sternotomy is used to access the heart, the intrapericardial portion of the pulmonary vessels, the ascending aorta and aortic arch, the SVC and IVC, and the innominate artery. Branches of the innominate artery are exposed by extending the median sternotomy into the neck.

A posterolateral left thoracotomy in the fourth intercostal space is used to approach the descending thoracic aorta. The right subclavian artery is exposed via a median sternotomy that is extended into the neck. Proximal control for the left subclavian artery is achieved through an anterolateral left thoracotomy in the third intercostal space. Distal control for this vessel is obtained through a supraclavicular incision.

The distal esophagus can be approached via a left posterolateral thoracotomy; more proximal injuries require a right thoracotomy. The thoracic duct is approached through a right thoracotomy.

Injuries to the lung or more peripheral pulmonary vessels are accessed through a posterolateral thoracotomy. Injuries to the proximal two thirds of the trachea are best approached through a collar incision and extension via a T-incision through the manubrium, which allows exposure to the middle and distal trachea. Injuries to the distal trachea, the carina, or the right mainstem bronchus are best approached through a right fourth intercostal posterolateral thoracotomy. Injuries to the left mainstem bronchus are best approached through a left posterolateral thoracotomy.

Postoperative Care

Patients are extubated as soon as feasible in the postoperative period. Monitoring devices are kept in place while needed but are removed as soon as possible.

Intravenous fluids are provided until the patient has had a return of GI function, at which time the patient can be fed. Patients with severe associated injuries, especially those in a coma, may require prolonged enteral tube feedings.

Pain control[47] is important in these patients because it facilitates breathing and helps to prevent pulmonary complications such as atelectasis and pneumonia. Chest physiotherapy and nebulizer treatments are used as necessary, and the use of an incentive spirometer is encouraged.

Chest tubes are placed for suction until fluid drainage has fallen sufficiently and the lung is completely expanded without evidence of air leak. Tubes may then be placed to water seal and may be removed if a chest radiograph demonstrates continued lung expansion.

Complications

Patients with blunt thoracic trauma are subject to myriad complications during the course of their care.

Wound complications include the following:

  • Wound infection
  • Wound dehiscence (particularly problematic in  sternal wounds)

Cardiac complications include the following:

Pulmonary and bronchial complications include the following:

Vascular complications include the following:

Neurologic complications include the following:

  • Causalgia (injuries that involve the brachial plexus)
  • Paraplegia (the spinal cord is at risk during repair of a ruptured thoracic aorta)
  • Stroke

Esophageal complications include the following:

Complications involving the bony skeleton include the following:

  • Skeletal deformity
  • Chronic pain
  • Impaired pulmonary mechanics

Long-Term Monitoring

After discharge, patients are monitored to ensure that adequate wound healing has occurred and to assess for the development of complications. Patients with vascular injuries and grafts may be monitored to ensure that complications such as pseudoaneurysms do not develop.

 

Guidelines

EAST Guidelines for ED Thoracotomy

In 2015, the Eastern Association for the Surgery of Trauma (EAST) published a practice management guideline on patient selection for emergency department (ED) thoracotomy.[28] The following recommendations are pertinent to blunt chest trauma:

  • Patients presenting pulseless to the ED with signs of life after blunt injury - Conditional recommendation in favor of ED thoracotomy (moderate-quality evidence) 
  • Patients presenting pulseless to the ED without signs of life after blunt injury - Conditional recommendation against ED thoracotomy (low-quality evidence)

EAST Guidelines for Blunt Aortic Injury

In 2015, the EAST published a practice management guideline on evaluation and management of blunt traumatic aortic injury (BTAI),[46] which included the following recommendations:

  • Patients with suspected BTAI - Strong recommendation in favor of computed tomography (CT) of the chest with intravenous contrast for diagnosis of clinically significant BTAI (low-quality evidence)
  • Patients diagnosed with BTAI - Strong recommendation in favor of using endovascular repair in patients without contraindications for such repair (low-quality to moderate-quality evidence)
  • Patients diagnosed with BTAI - Suggestion in favor of delayed repair as opposed to immediate repair (very-low-quality to high-quality evidence)

EAST Guidelines for Pulmonary Contusion and Flail Chest

In 2012, the EAST published a practice management guideline on management of pulmonary contusion and flail chest.[32]  Recommendations were stratified as follows:

  • Level 1 - Convincingly justifiable on the basis of the available scientific evidence alone
  • Level 2 - Reasonably justifiable on the basis of the available scientific evidence and strongly supported by expert opinion
  • Level 3 - Supported by the available data but lacking adequate scientific evidence

No level 1 recommendations were made.

Level 2 recommendations included the following:

  • Patients should not be excessively fluid-restricted but should be resuscitated as necessary; once this is done, unnecessary fluid administration should be avoided
  • A pulmonary artery catheter may be useful
  • In the absence of respiratory failure, obligatory mechanical ventilation solely for overcoming chest-wall instability should be avoided
  • Patients needing mechanical ventilation should be supported according to institutional and physician preference and separated from the ventilator as soon as possible; positive end-expiratory pressure (PEEP)/continuous positive airway pressure (CPAP) should be included
  • Optimal analgesia and aggressive chest physiotherapy should be applied to minimize the likelihood of respiratory failure and ensuing ventilatory support
  • Steroids should not be used

Level 3 recommendations included the following:

  • A trial of mask CPAP should be considered in alert, compliant patients with marginal respiratory status in combination with optimal regional anesthesia
  • Paravertebral analgesia may be considered in certain situations when epidural analgesia is contraindicated
  • Independent lung ventilation may be considered in severe unilateral PC when shunt cannot be otherwise corrected or when crossover bleeding is problematic
  • High-frequency oscillatory ventilation (HFOV) should be considered for patients failing conventional ventilatory modes
  • Diuretics may be used in the setting of hydrostatic fluid overload or in the setting of known concurrent congestive heart failure
  • Surgical fixation of flail chest may be considered in severe cases when patients cannot be weaned from the ventilator or when thoracotomy is required for other reasons
  • Rib plating or wrapping devices are likely superior to intramedullary wires for surgical fixation of rib fractures, and these should be preferred for this purpose
  • Self-activating multidisciplinary protocols for the treatment of chest-wall injuries should be considered where feasible

EAST Guidelines for Screening for Blunt Cardiac Injuries

In 2012, the EAST published a practice management guideline on screening for blunt cardiac injury (BCI).[27]  Recommendations were stratified as follows:

  • Level 1 - Convincingly justifiable on the basis of the available scientific evidence alone
  • Level 2 - Reasonably justifiable on the basis of the available scientific evidence and strongly supported by expert opinion
  • Level 3 - Supported by the available data but lacking adequate scientific evidence

The single level 1 recommendation was that electrocardiography (ECG) should be performed at admission on all patients in whom BCI is suspected (no change)..

Level 2 recommendations included the following:

  • If the admission ECG reveals a new abnormality, the patient should be admitted for continuous ECG monitoring; if the patient has preexisting abnormalities, comparison should be made to a previous ECG to determine need for monitoring
  • In patients with a normal ECG result and normal troponin I level, BCI is ruled out; patients with normal ECG results but elevated troponin I level should be admitted to a monitored setting
  • For patients with hemodynamic instability or persistent new arrhythmia, an echocardiogram should be obtained; if optimal transthoracic echocardiography (TTE) cannot be performed, transesophageal echocardiography (TEE) should be performed
  • The presence of a sternal fracture alone does not predict the presence of BCI and thus should not prompt monitoring in the setting of normal ECG result and troponin I level
  • Creatinine phosphokinase with isoenzyme analysis should not be performed
  • Nuclear medicine studies should not be routinely performed

Level 3 recommendations included the following:

  • Elderly patients with known cardiac disease, unstable patients, and patient with an abnormal admission ECG result can safely undergo surgery if appropriately monitored; placement of a pulmonary artery catheter may be considered
  • With suspected BCI, troponin I should be routinely measured; if elevated, patients should be admitted to a monitored setting and troponin I followed up serially
  • Cardiac CT or magnetic resonance imaging (MRI) can help differentiate acute myocardial infarction (AMI) from BCI in trauma patients with abnormal ECG results, cardiac enzymes, or echocardiograms to determine need for cardiac catheterization or anticoagulation