As with all trauma patients, the evaluation of a patient with thoracic trauma begins with a determination of airway patency, adequacy of breathing, hemodynamic stability, and neurological status. Where available, ultrasound and chest X-ray are useful diagnostic adjuncts.

Pneumothorax, Hemothorax

1. In a patient with thoracic trauma and a clinically patent airway who has rapid, inadequate, or labored respirations, the diagnosis of pneumothorax must be assumed until proven otherwise.
2. Absent or markedly decreased breath sounds in a patient with known thoracic trauma indicate the need for intervention without additional diagnostic testing. In addition to treating pneumothorax or hemothorax when present, tube thoracostomy may be diagnostic of these conditions based on a rush of air or blood after tube placement.
3. In a patient with normal hemodynamics and adequate oxygenation and ventilation, it is reasonable to confirm a pneumothorax by chest X-ray or ultrasound prior to tube thoracostomy.

Tension Pneumothorax

1. Signs and symptoms of tension pneumothorax include severe or progressive shortness of breath or hemodynamic compromise in the setting of chest trauma.
2. Differentiating between a simple pneumothorax and a tension pneumothorax is based on the presence of hemodynamic effects (hypotension and decreased perfusion) in the latter condition. While a patient with thoracic trauma and a pneumothorax may present with multiple injuries and an alternate explanation for hypotension (such as cardiac tamponade, intraabdominal bleeding, or hemothorax), immediate needle or tube thoracostomy is the necessary first step in this scenario. In the case of a tension pneumothorax, this maneuver should have both diagnostic and therapeutic benefit.
3. Patients who are hypovolemic are more susceptible to the hemodynamic effects of tension pneumothorax.

Open Pneumothorax (Sucking Chest Wound)

Open pneumothorax occurs when a defect in the chest wall is sufficiently large to impair effective air exchange (air will preferentially pass through the defect if larger than 2/3 the tracheal diameter). In the case of an open pneumothorax due to a large chest wall defect, the diagnosis will be clinically obvious on physical examination.

Rib Fractures, Flail Chest

1. Rib fractures are a clinical diagnosis based on chest wall pain and point tenderness (with or without crepitus) in the setting of blunt or penetrating chest wall trauma.
2. Maintain a high index of suspicion for associated injuries (pulmonary contusion, pneumothorax, splenic or liver laceration, etc.).
3. Rib fractures are associated with pneumothorax, hemothorax, solid abdominal organ injury, and thoracic great vessel injury. Patients must be assessed for these associated injuries.
4. Flail chest may be diagnosed clinically by gross chest wall instability or paradoxical chest wall movement with respiration. Practically, the differentiation between rib fractures alone and a flail segment is not important, as the initial management is the same for both conditions. The morbidity of this type of injury is determined by the underlying pulmonary contusion which may impair gas exchange and the consequences of low lung volumes due to pain.

Pulmonary Contusion

1. Pulmonary contusion is most common with blunt trauma or blast injury.
2. Patients with pulmonary contusion may present with respiratory distress and reduced breath sounds on the injured side. Often, symptoms may not manifest immediately after injury. Chest X-ray may show patchy opacity(s). However, lung contusion is primarily a clinical diagnosis.
3. It can be difficult to differentiate between pulmonary contusion and pneumothorax when imaging is not available. In this scenario, if the patient is significantly symptomatic and does not improve with initial pain management, one must assume that pneumothorax is present, and tube or needle thoracostomy is indicated (particularly prior to transport).

Cardiac Tamponade

1. For low-velocity penetrating injuries, the possibility of intra-pericardial cardiac or great vessel injury should be considered when there is penetrating trauma in the “box” defined by the space inferior to the clavicles, superior to the costal margin and medial to the mid-clavicular line.
2. With high velocity gunshot wounds and multiple penetrating blast fragment wounds, intra-pericardial damage is possible with any penetrating injury to the chest or upper abdomen.
3. Ultrasound assessment is a rapid, simple, and widely available tool to assess for significant hemopericardium, which indicates intra-pericardial injury in this setting. When a hemopericardium and hypotension co-exist in a patient with significant trauma (of any mechanism), no further diagnostic evaluation is indicated. However a negative pericardial ultrasound in penetrating chest trauma does not definitively rule out cardiac injury or pericardial blood as sometimes blood can drain from the pericardium into either the right or left chest if there is a hole in the pleural pericardium.
4. Classic physical exam findings of tamponade (distended neck veins, muffled heart sounds) are not reliable.
5. In a hypotensive patient undergoing exploratory laparotomy for penetrating abdominal injury, a trans-diaphragmatic pericardial window is a rapid means to evaluate for hemopericardium/tamponade.

Great Vessel Injury

1. Most combat-related great vessel injuries are fatal at the point of injury.
2. In some cases, particularly after major blunt trauma, a patient may present with a contained great vessel injury associated with a mediastinal hematoma. Although a widened mediastinum on plain chest X-ray may be suggestive of this injury, computed tomographic angiography is necessary for diagnosis. Other X-ray findings suggestive of great vessel injury include apical capping, tracheal deviation, wide paratracheal stripe, and downward deviation of the left main bronchus.
3. If a contained great vessel injury is suspected (mediastinal hematoma), such an injury is unlikely to acutely cause hypotension, and other causes of bleeding and hypotension should be sought.

Esophageal Perforation

1. Esophageal perforation is a rare injury since the esophagus is protected in the posterior mediastinum. It may be suspected due to wound trajectory, and occurs most often in association with other penetrating injuries.
2. The diagnosis is commonly delayed and there should be high index of suspicion for this rare injury depending on mechanism of injury and fragment trajectories. The diagnosis may be suspected or confirmed after placement of a tube thoracostomy for a pleural effusion/hemothorax. Contents of the drainage may contain gastrointestinal contents.
3. Endoscopy, esophagram and/or computed tomographic (CT) scan can confirm the diagnosis.6

Tracheobronchial Injuries

1. Penetrating proximal thoracic tracheobronchial injuries are rarely encountered due to their proximity to the great vessels and heart and subsequent lethality.
2. Diagnosis requires a high index of suspicion. The most common diagnostic signs are subcutaneous emphysema, pneumothorax and hemoptysis. Hoarseness and dysphonia are also common symptoms. Respiratory failure, the presence of a pneumothorax on chest X-ray, or a large air leak after tube thoracostomy are typical but non-specific findings.
3. If there is concern for a tracheobronchial injury, bronchoscopy should be performed with documentation of injury location and severity of injury.7 The most common locations are in the distal trachea and proximal mainstem bronchi (within 2cm of the carina).

Diaphragmatic Injuries

1. Diaphragm injuries commonly occur with high energy blunt trauma or penetrating thoracoabdominal injuries. Diaphragm injury should be considered in any thoracoabdominal penetrating trauma.
2. Auscultation of bowel sounds in the chest are highly suggestive of diaphragm injury but are rarely identified. On ultrasound exam, bowel may be seen in the chest. If there is concern for diaphragm injury, placement of a nasogastric tube with subsequent chest X-ray may confirm the diagnosis.
3. Small diaphragm injuries typically go undetected until direct examination of the diaphragm at the time of surgery (laparotomy, laparoscopy, thoracotomy, thoracoscopy). A high index of suspicion for diaphragm injury should be maintained for penetrating wounds to the left and right upper quadrant.

Diaphragm injuries may allow blood from the abdomen to be drawn into the negative pressure region of the chest. In this case, abdominal bleeding may present as a hemothorax.