Understanding Thoracic Trauma
Chest injuries account for approximately 25% of all trauma deaths. The thorax contains vital organs including the heart, great vessels, lungs, and esophagus, all protected by the relatively rigid rib cage. Injuries to these structures can rapidly become life-threatening. As an EMS provider, your ability to quickly identify chest injuries, understand their pathophysiology, and initiate appropriate interventions can mean the difference between life and death.
Chest injuries are classified as either blunt or penetrating. Blunt chest trauma (from motor vehicle collisions, falls, or assaults) causes injury through compression, deceleration, and shearing forces. Penetrating chest trauma (from gunshots, stabbings, or impalement) causes direct tissue destruction. Both mechanisms can produce the same life-threatening conditions, though the presentation and management may differ.
Pneumothorax
A pneumothorax occurs when air enters the pleural space (the potential space between the lung and the chest wall), causing the lung to collapse. A simple pneumothorax results from a ruptured bleb or small tear in the lung. Patients present with pleuritic chest pain, dyspnea, decreased breath sounds on the affected side, and tachycardia. A simple pneumothorax is uncomfortable but not immediately life-threatening.
A tension pneumothorax is a life-threatening emergency. Air enters the pleural space through a one-way valve mechanism, progressively accumulating with each breath but unable to escape. The increasing pressure collapses the affected lung completely, then shifts the mediastinum (the central structures including the heart and great vessels) toward the opposite side, compressing the unaffected lung and kinking the great vessels. Signs include severe respiratory distress, absent breath sounds on the affected side, hypotension, jugular venous distension (JVD), and tracheal deviation away from the affected side (a late finding). Treatment at the paramedic level includes needle decompression: inserting a large-bore needle (14-gauge, at least 3.25 inches long) into the second intercostal space at the midclavicular line on the affected side to release trapped air.
Hemothorax
A hemothorax is the accumulation of blood in the pleural space, usually from lacerated intercostal vessels, internal mammary arteries, or lung parenchyma. Each hemithorax can hold up to 3 liters of blood, meaning a massive hemothorax can cause hemorrhagic shock. Findings include decreased breath sounds on the affected side (due to blood), signs of shock (tachycardia, hypotension, pale skin), and dullness to percussion on the affected side. Prehospital management focuses on high-flow oxygen, IV fluid resuscitation for shock, and rapid transport to a trauma center where a chest tube can be placed.
Flail Chest
A flail chest occurs when three or more adjacent ribs are fractured in two or more places, creating a free-floating segment of chest wall. This segment moves paradoxically during breathing: inward during inspiration and outward during expiration. The real danger is not the paradoxical motion itself but the underlying pulmonary contusion (bruised lung tissue) that almost always accompanies it. Pulmonary contusion causes progressive hypoxia as bruised tissue fills with fluid and blood. Management includes high-flow oxygen, positive pressure ventilation if the patient develops respiratory failure, stabilizing the flail segment with a bulky dressing or pillow (though this is less emphasized in current guidelines), and rapid transport. Pain control is critical; rib fractures are extremely painful, and pain limits the patient's ability to breathe deeply.