Chapter 19: Chest Trauma

Introduction

Although the chest wall can absorb significant amounts of trauma without serious injury to the patient, chest trauma is a frequent indication for critical care and mechanical ventilation. Unlike other disease states requiring mechanical ventilation (eg, chronic obstructive pulmonary disease [COPD]), patients suffering chest trauma are typically young and previously healthy and an increasing number are being managed with noninvasive approaches.

Overview

Blunt Chest Trauma

With blunt chest trauma, there are often no exterior signs or symptoms of injury to the chest. Clinical entities associated with blunt chest trauma include fractures, pulmonary contusion, tracheobronchial injury, myocardial and vascular injury, esophageal perforation, and diaphragmatic injury. Fractures can involve the ribs, sternum, vertebrae, clavicles, or scapulae. Of these, rib fractures are the most common. Rib fractures without flailing can be painful, resulting in splinting, atelectasis, and hypoxemia due to ventilation/perfusion mismatching. Isolated rib fractures almost never necessitate mechanical ventilation unless they are associated with other injuries such as pulmonary contusion. Flail chest is a loss of stability of the rib cage caused by multiple rib fractures, which frequently results in significant ventilatory disturbances due to underlying damage to the lung parenchyma, inefficient expansion of the thorax due to paradoxical movement of the chest wall, and pain leading to hypoventilation. Until recently, it was common practice to internally stabilize the rib cage in patients with flail chest by use of positive pressure ventilation and positive end-expiratory pressure (PEEP). Many patients with flail chest are now adequately managed without intubation and mechanical ventilation. This is particularly the case with appropriate pain control and noninvasive ventilation (NIV). It is now generally accepted that mechanical ventilation is only required for patients with flail chest if one of the following is present: shock, closed head injury, need for immediate operation, severe pulmonary dysfunction, or deteriorating respiratory status.

Pulmonary contusion results from high impact blunt chest trauma, which produces leakage of blood and protein from the vascular to the interstitial and alveolar space of the lungs. Clinically, pulmonary contusion is similar in presentation and treatment to acute respiratory distress syndrome (ARDS). If the contusion is localized, high levels of PEEP may produce a paradoxical decrease in arterial oxygenation because blood may be diverted from normal to the injured lung increasing shunt fraction. Mild to moderate forms of pulmonary contusion may not require intubation, and hypoxemia can be adequately treated with oxygen and mask continuous positive airway pressure (CPAP) or NIV.

Tracheobronchial injuries most often occur near ...