Thoracic Trauma: What You Need to Know

Its presentation can be subtle, but its consequences severe.


Scott Snyder and Kevin Collopy are featured speakers at EMS World Expo, October 29–November 2, in New Orleans, LA.

This CE activity is approved by EMS World Magazine, an organization accredited by the Continuing Education Coordinating Board for Emergency Medical Services (CECBEMS), for 1.5 CEUs. There are two ways to take the CE test that accompanies this article and receive 1.5 hours of CE credit accredited by CECBEMS: 1. Click here to download a PDF of the test. The PDF has instructions for completing the test. 2. Or go to www.rapidce.com to take the test and immediately receive your CE credit. Questions? E-mail editor@EMSWorld.com.

Objectives

  • Review chest wall injuries
  • Review pulmonary injuries
  • Review cardiovascular injuries
  • Discuss prehospital assessment and management of thoracic trauma

In 2009 trauma was again the country’s leading cause of death for those aged 1–44 years, according to the CDC.1 It is estimated that thoracic trauma accounts for about 20%–25% of all deaths resulting from trauma, or about 16,000 annually in the U.S. Common intrathoracic injuries resulting in death include tension pneumothorax, uncontrolled hemorrhage, airway obstruction and cardiac tamponade.2

The early presentation of severe, life-threatening intrathoracic injury can sometimes be subtle. This article reviews the pathophysiology, clinical exam findings and prehospital management of these injuries, allowing prehospital providers to better anticipate, identify and treat them in the field. For purposes of this article, thoracic trauma will be divided into three classes: chest wall injuries, pulmonary injuries and cardiovascular injuries.

Chest Wall Injuries

An intact thoracic cage is required for adequate ventilation (see Figure 1). Any blunt chest wall injury that results in inadequate ventilation can lead to hypoxia, hypercarbia and eventually acidosis and respiratory failure. Blunt chest wall injuries include rib fractures from a single rib to a flail chest, as well as sternal fractures. Alternatively, penetrating chest trauma can cause hypoxia with hypocarbia as inspiratory pressure is lost.

Rib and Sternal Fractures

Rib fractures are the most common form of significant chest injury, resulting from more than half of cases of blunt trauma to the chest. The issue with a rib fracture is not in the fracture itself; an isolated rib fracture is painful but not life-threatening. The danger with rib fractures lies with the potential for underlying injury such as pneumothorax, hemothorax, cardiac injury, and liver and spleen lacerations.

Fractures to the first three ribs are uncommon, as they are short and stiff and protected by the clavicle, scapula and muscles of the upper chest wall. A fracture to these ribs suggests significant force was transmitted into the thorax, and the risk of intrathoracic injury is high. The presence of two or more rib fractures at any level on the thoracic cage is associated with a higher incidence of internal injuries.

Ribs 4–9 are the most commonly injured because of their exposed position and relative immobility, as they are attached to the sternum anteriorly and the spine posteriorly. Fractures to ribs 9–11 are associated with increased risk of intra-abdominal injury, specifically to the liver and spleen.

Sternal fracture and costochondral separation (separation of the sternum from the ribs) are most often caused by anterior blunt force trauma, the most frequent mechanism being collision of the chest with a steering wheel. In one study, motor vehicle collisions accounted for 68% of all sternal fractures.3 Contrary to intuition, a restrained passenger is more likely than an unrestrained passenger to suffer sternal fracture. The occurrence of sternal fractures has increased threefold since the widespread use of over-the-shoulder seat belts.4 During frontal collisions (which often result in rapid deceleration), the compressive force generated when the anterior chest strikes the seat belt is often significant enough to result in sternal fracture or separation from the ribs.

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