Thoracic Trauma

Chapter 100


Thoracic Trauma



The initial management of thoracic trauma should be identical to that of other traumatic injuries: rapid evaluation of airway, breathing, and circulation followed by a secondary assessment of injuries as delineated in the Advanced Trauma Life Support (ATLS) guidelines (see Chapter 96). Patients presenting with trauma to the thorax, however, may require rapid interventions unique to the mechanism of injury such as chest tube thoracostomy or pericardiocentesis. Although these interventions are often performed only after radiographic imaging, patients presenting with thoracic trauma may require such a procedure before imaging can be obtained. A chest radiograph should be attained in the trauma bay as soon as possible and should be evaluated for pneumothorax, subcutaneous or mediastinal emphysema, diaphragmatic rupture, widened mediastinum, and foreign bodies. The primary and secondary surveys, along with the initial chest radiograph, are usually sufficient to guide the provider along a tri-directional decision tree: additional imaging, tube thoracostomy, or the operating room. This chapter discusses in greater detail the variety of injuries and interventions associated with blunt and penetrating thoracic trauma.



Scope of Injuries and Management



Chest Wall Injuries


Injuries to the chest wall include fractures of the ribs, sternum, clavicle, scapula, and flail chest. It is important to note that blunt chest wall trauma, as opposed to penetrating trauma, is often associated with more severe intrathoracic injuries. Blunt thoracic trauma causes injury by three distinct (often overlapping) mechanisms: deceleration, direct impact, and compression. Deceleration injuries damage the structures suspended within and adhered to the thorax, such as the heart, lungs, and aorta. Direct impact typically causes localized fractures of the ribs or sternum but can also damage the underlying heart or lungs. Compression injuries, similar to those caused by direct impact, can involve not only the surrounding thoracic wall but also, when severe enough, organs and vessels within. It is thus critical for the clinician to be cognizant of the fact that any trauma to the chest wall can be associated with much more severe intrathoracic damage.


The most common injury to the thorax is rib fracture. The diagnosis can usually be made by simply observing the patient’s respiratory pattern and level of pain upon deep inspiration. The treatment of unilateral rib fractures is pain control. For multiple or bilateral fractures, a more aggressive and complex analgesic plan is usually required, often involving some form of neuraxial anesthetic (e.g., epidural catheter), paravertebral block, or intercostal nerve block (see Chapter 86).


When trauma causes a part of the chest wall to move separately from the surrounding bony structures, a paradoxical motion occurs with respiration known as “flail chest.” The flail portion moves inward as the patient takes an active inspiratory effort. Flail chest can result from unilateral or bilateral rib fractures, or disruption of the costochondral junction. It is seen more commonly in elderly patients because of their reduced chest wall compliance. As a result of the discordance between the motion of the chest wall and the intrathoracic volume, there is decreased vital capacity and ineffective ventilation, which, when coupled with an underlying pulmonary contusion, can result in the development of acute respiratory distress syndrome (ARDS). Early intervention, including pain control, humidification of air, and aggressive pulmonary toilet, is critical in order to avoid clinical deterioration. Arterial blood gases can be followed to evaluate the adequacy of ventilation and oxygenation over a short period of time. Non-invasive ventilation is often unsuccessful because the primary problem remains severe pain and discordant chest movement; however, obligatory intubation without evidence of respiratory failure is not recommended. If clinical improvement is not seen rapidly, elective mechanical ventilation should be considered. Mortality has improved significantly over the years from flail chest, but many patients suffer from long-term debilitation including dyspnea, abnormal exercise tests, and pain. In short, flail chest is a serious injury that must be managed early and aggressively.


Other fractures of the chest wall include those of the sternum, clavicle, and scapula. Sternal fractures are frequently secondary to motor vehicle crashes. Although imaging can be helpful, diagnosis can often be made by physical examination demonstrating point tenderness and sternal deformity. Myocardial injury is frequently associated with these fractures; however, the clinical significance varies by patient. The treatment of chest wall fractures is similar to that of rib fractures except in cases where the fracture is severely displaced. Such cases require operative intervention. Scapular fractures are rare but are almost always associated with concomitant injury, particularly within the brachial plexus. Treatment is mostly nonoperative, although there are specific fracture patterns that require an operation. There are no defined guidelines for surgical intervention of chest wall fractures. Therapy is typically individualized based on the fracture type and other comorbidities. Unlike scapular fractures, those of the clavicle are often isolated and have little clinical consequence.



Lung and Myocardial Contusion


Myocardial contusion is usually secondary to blunt chest trauma. Serum troponin levels, though not specific for contusion, are a sensitive indicator of myocardial injury. Patients with normal troponin levels, normal electrocardiogram, and no other significant injuries typically do not require hospital admission. Elevated troponin levels require admission and monitoring until they return to normal. Early sequelae of cardiac contusion include ventricular arrhythmia, ventricular wall rupture, septal rupture, valvular insufficiency, intracardiac thrombus formation, and laceration of coronary artery resulting in myocardial infarction. Manifestations of these complications typically occur within the first 24 to 48 hours after injury. Echocardiography is indicated when there is hemodynamic instability, a discrepancy between troponin levels and ECG findings, and when troponin levels continue to rise. In general, the treatment of myocardial contusion is supportive.


Pulmonary contusion can result from severe blunt chest wall trauma causing intraparenchymal hemorrhage and edema. It is usually apparent on the initial chest radiograph, though it may not become apparent until 24 to 48 hours after the initial injury. Indications for endotracheal intubation are similar to those of other chest trauma and should be guided by clinical judgment and arterial blood gas trends. Fluid restriction is appropriate in elderly patients and those with evidence of volume overload; however, not all pulmonary contusion patients warrant fluid restriction and diuresis. Massive contusions causing large intrapulmonary shunts with hypoxemia can be managed with a double-lumen endotracheal tube. It is important to distinguish a pulmonary hematoma from a contusion on initial chest film. After 24 to 48 hours, a hematoma will appear as a discrete mass on chest radiography or computed tomography (CT) scan and is usually of minor clinical consequence.

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Jul 7, 2016 | Posted by in CRITICAL CARE | Comments Off on Thoracic Trauma

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